A control method and device of an air conditioning system, the air conditioning system and a storage medium

Abstract

The application discloses a control method and device of an air conditioning system, the air conditioning system and a storage medium, and relates to the technical field of air conditioning systems. The method comprises the following steps: after power-on, if the compressor is not started, performing preset stop detection logic according to the current continuous stop time of the compressor and the currently recorded outdoor environment temperature and suction pressure value; if the compressor has been started, performing preset operation detection logic according to the currently recorded outdoor environment temperature and suction pressure value; obtaining a first type cumulative count value and / or a second type cumulative count value of the number of times of low-pressure protection of the compressor; and controlling the compressor to resume operation in combination with the first type cumulative count value and the second type cumulative count value. According to the scheme, the number of times of low-pressure protection of the compressor is classified and counted according to the interval of the outdoor environment temperature, and whether the compressor automatically resumes operation after being locked by low-pressure protection is determined in combination with the outdoor environment temperature, so that the low-pressure protection of the compressor is timely and effective, manual intervention can be reduced, and operation and maintenance costs can be reduced.

Description

Technical Field

[0001] This invention belongs to the field of air conditioning system technology, specifically relating to a control method, device, air conditioning system, and storage medium for an air conditioning system, and particularly to a compressor low-pressure protection control method, device, air conditioning system (such as a computer room air conditioner or other large multi-split system), and storage medium for an air conditioning system (such as a computer room air conditioner or other large multi-split system). Background Technology

[0002] In engineering applications, air conditioning systems (such as computer room air conditioners or other large multi-split systems) often involve long connecting pipes between the indoor and outdoor units, typically exceeding 20 meters, and in some cases reaching nearly 100 meters. When the compressor is located on the indoor unit side, in extremely low outdoor temperatures (e.g., below -30°C), the refrigerant flow is slow during the compressor's start-up phase, easily causing a vacuum-like situation and triggering the compressor's low-pressure protection. This is especially problematic when cost control is a primary concern, particularly if a compressor with poor low-pressure performance is selected. If the low-pressure protection is not timely, compressor damage is highly likely. However, unlimited low-pressure protection means the compressor is operating in an unreliable low-pressure range without limit, further increasing the risk of compressor failure.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The purpose of this invention is to provide a control method, device, air conditioning system, and storage medium for an air conditioning system. This addresses the problem that untimely low-pressure protection of the compressor in air conditioning systems (such as computer room air conditioners or other large multi-split systems) can easily damage the compressor; and that unlimited low-pressure protection can also lead to compressor damage. The invention achieves this by categorizing and cumulatively counting the number of low-pressure protection calls based on the outdoor ambient temperature range, and combining the outdoor ambient temperature with the total cumulative count to determine whether the compressor automatically resumes operation after being locked by low-pressure protection. This ensures timely and effective low-pressure protection while preventing excessive cumulative low-pressure protection calls from locking the compressor and preventing automatic recovery. It effectively reduces manual intervention and lowers maintenance costs.

[0005] This invention provides a control method for an air conditioning system, comprising: after the air conditioning system is powered on, collecting the operating parameters of the air conditioning system; recording the operating parameters of the air conditioning system before the compressor is turned on; if the compressor shuts down due to low-pressure protection, re-recording the operating parameters of the air conditioning system before the compressor is turned on; determining whether the compressor has been turned on; if it is determined that the compressor has not been turned on, when the compressor is subjected to low-pressure protection, executing a preset shutdown detection logic based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system; and during the execution of the preset shutdown detection logic, performing a categorized cumulative count of the number of times the compressor has undergone low-pressure protection based on the outdoor ambient temperature range in the currently recorded parameters of the air conditioning system, obtaining a first type of cumulative count value of the number of times the compressor has undergone low-pressure protection and / or a second type of cumulative count value of the number of times the compressor has undergone low-pressure protection. If it is determined that the compressor has been turned on, when the compressor is under low-pressure protection, a preset operation detection logic is executed according to the currently recorded operating parameters of the air conditioning system. During the execution of the preset operation detection logic, the number of times the compressor has underwent low-pressure protection is cumulatively counted according to the range of outdoor ambient temperature in the currently recorded parameters of the air conditioning system, resulting in a first type of cumulative count value and / or a second type of cumulative count value. After the compressor stops due to low-pressure protection, the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the compressor underwent low-pressure protection are combined to automatically unlock the compressor from its low-pressure protection state, so that the compressor can resume operation.

[0006] In some implementations, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system, a preset shutdown detection logic is executed; and during the execution of the preset shutdown detection logic, based on the range of the outdoor ambient temperature in the currently recorded parameters of the air conditioning system, the number of times the compressor experiences low-pressure protection is cumulatively counted by type, to obtain a first type of cumulative count value of the number of times the compressor experiences low-pressure protection and / or the pressure... The second type of cumulative count value for the number of times the compressor has low-pressure protection occurs includes: determining whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, the suction pressure value of the compressor currently recorded within the first set detection time is less than the first set pressure threshold, and the outdoor ambient temperature of the air conditioning system currently recorded is greater than the set outdoor ambient temperature threshold; if these conditions are met, the low-pressure protection situation of the compressor is displayed, the first type of cumulative count value for the number of times the compressor has low-pressure protection occurs is incremented by 1, and the compressor is kept off and prevented from starting; if these conditions are not met, the preset shutdown detection logic is stopped.

[0007] In some implementations, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; based on the currently recorded operating parameters of the air conditioning system, a preset operation detection logic is executed; and during the execution of the preset operation detection logic, based on the range of the outdoor ambient temperature in the currently recorded parameters of the air conditioning system, the number of times the compressor experiences low-pressure protection is cumulatively counted by type, to obtain a first type of cumulative count value and / or a second type of cumulative count value of the number of times the compressor experiences low-pressure protection, including: determining whether the following conditions are met: the currently recorded suction pressure value of the compressor is less than a first preset pressure threshold within a continuous second preset detection time, and the currently recorded outdoor ambient temperature of the air conditioning system is greater than a critical temperature setting value; if met, the first type of cumulative count value of the number of times the compressor experiences low-pressure protection is incremented by 1, and the compressor is kept off and prohibited from being turned on; if not met, the second type of cumulative count value of the number of times the compressor experiences low-pressure protection is incremented by 1, and the compressor is kept off and prohibited from being turned on.

[0008] In some implementations, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; after the compressor stops due to low-pressure protection, based on the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, the system automatically unlocks the compressor to allow it to resume operation, including: determining the sum of the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, and recording it as the total cumulative count value of the number of times the compressor has experienced low-pressure protection; determining whether the total cumulative count value of the number of times the compressor has experienced low-pressure protection is greater than or equal to a preset shutdown protection number threshold; if so, then based on the currently recorded outdoor ambient temperature of the air conditioning system... The system uses the temperature, the first cumulative count of the number of times the compressor has experienced low-pressure protection, and the second cumulative count of the number of times the compressor has experienced low-pressure protection to determine whether to display the low-pressure protection status of the compressor and to automatically unlock the compressor that has stopped due to low-pressure protection, so that the compressor can resume operation. The currently recorded outdoor ambient temperature of the air conditioning system is the outdoor ambient temperature of the air conditioning system recorded after the total cumulative count of the number of times the compressor has experienced low-pressure protection minus one instance of compressor shutdown due to low-pressure protection, and before the compressor is restarted. If this condition is not met, the system uses the current continuous shutdown time of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection to automatically unlock the compressor that has stopped due to low-pressure protection, so that the compressor can resume operation.

[0009] In some implementations, based on the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, it is determined whether to display the low-pressure protection status of the compressor and to automatically unlock the compressor from shutdown due to low-pressure protection, so that the compressor can resume operation. This includes: determining whether the currently recorded outdoor ambient temperature critical temperature setting of the air conditioning system is met; if so, displaying the low-pressure protection status of the compressor and keeping the compressor off and preventing it from starting; if not, not displaying the low-pressure protection status of the compressor and keeping the compressor off and preventing it from starting; and determining whether the currently recorded outdoor ambient temperature of the air conditioning system is greater than the critical temperature setting within a third consecutive set detection time; if so, clearing the second cumulative count of the number of times the compressor has experienced low-pressure protection, and then determining whether the sum of the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection is less than a preset shutdown protection threshold. If the condition is not met, then determine whether the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than the preset shutdown protection threshold. If it is determined that the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than the preset shutdown protection threshold, then clear the display of the compressor experiencing low-pressure protection. Then, based on the current continuous shutdown time of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, control the compressor to automatically unlock the shutdown due to low-pressure protection, so that the compressor can resume operation. If it is determined that the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is greater than or equal to the preset shutdown protection threshold, then return to display the compressor experiencing low-pressure protection, keep the compressor off, and prevent the compressor from starting.

[0010] In some implementations, based on the compressor's current continuous downtime, the currently recorded compressor suction pressure value, the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, the system automatically unlocks the compressor from shutdown due to low-pressure protection, allowing the compressor to resume operation. This includes determining whether the following conditions are met: the compressor's current continuous downtime is greater than a set downtime, and the currently recorded compressor suction pressure value is greater than a second set pressure within a fourth consecutive set detection time. If these conditions are met, the system automatically unlocks the compressor from shutdown due to low-pressure protection, allowing the compressor to resume operation. After the compressor resumes operation, the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection are adjusted based on the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running. If the adjustment is not satisfied, the process returns to normal. After the compressor stops due to low-pressure protection, the system continues to automatically unlock the compressor's low-pressure protection status by combining the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, so that the compressor can resume operation.

[0011] In some implementations, the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection are adjusted, taking into account the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running. This includes: determining whether the currently recorded outdoor ambient temperature of the air conditioning system is greater than a critical temperature setting within a fifth consecutive set detection time; if so, clearing the second cumulative count of the number of times the compressor has experienced low-pressure protection, and then determining whether the compressor has started running within a sixth consecutive detection time; if not, determining whether the compressor has started running within the sixth consecutive detection time; if it is determined that the compressor has started running within the sixth consecutive detection time, clearing both the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, and then returning to re-record the operating parameters of the air conditioning system before the compressor started; if it is determined that the compressor has not started running within the sixth consecutive detection time, returning to re-record the operating parameters of the air conditioning system before the compressor started.

[0012] In conjunction with the above method, another aspect of the present invention provides a control device for an air conditioning system, comprising: a data acquisition unit configured to acquire operating parameters of the air conditioning system after the air conditioning system is powered on; record the operating parameters of the air conditioning system before the compressor is turned on; and if the compressor shuts down due to low-pressure protection, re-record the operating parameters of the air conditioning system before the compressor is turned on; a control unit configured to determine whether the compressor has been turned on; the control unit is further configured to, if it is determined that the compressor is not turned on, execute a preset shutdown detection logic based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system when performing low-pressure protection on the compressor; and, during the execution of the preset shutdown detection logic, perform a categorized cumulative count of the number of times the compressor has performed low-pressure protection based on the range of outdoor ambient temperature in the currently recorded parameters of the air conditioning system, to obtain a first-type cumulative count value of the number of times the compressor has performed low-pressure protection and / or the number of times the compressor has performed low-pressure protection. The control unit is further configured to, if it is determined that the compressor has been turned on, execute a preset operation detection logic based on the currently recorded operating parameters of the air conditioning system when performing low-pressure protection on the compressor; and during the execution of the preset operation detection logic, perform a categorized cumulative count of the number of times the compressor has performed low-pressure protection based on the range of outdoor ambient temperature in the currently recorded parameters of the air conditioning system, to obtain a first-type cumulative count value and / or a second-type cumulative count value of the number of times the compressor has performed low-pressure protection; the control unit is further configured to, after the compressor stops due to low-pressure protection, combine the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first-type cumulative count value and the second-type cumulative count value of the number of times the compressor has performed low-pressure protection, to automatically unlock the compressor from the low-pressure protection shutdown state, so that the compressor can resume operation.

[0013] In some embodiments, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; the control unit executes a preset shutdown detection logic based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system; and during the execution of the preset shutdown detection logic, based on the range of the outdoor ambient temperature in the currently recorded parameters of the air conditioning system, it performs a categorized cumulative count of the number of times the compressor experiences low-pressure protection, obtaining a first-type cumulative count value of the number of times the compressor experiences low-pressure protection and / or The second type of cumulative count value for the number of times the compressor experiences low-pressure protection includes: determining whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, the suction pressure value of the compressor currently recorded within the first set detection time is less than the first set pressure threshold, and the outdoor ambient temperature of the air conditioning system currently recorded is greater than the set outdoor ambient temperature threshold; if these conditions are met, the low-pressure protection status of the compressor is displayed, the first type of cumulative count value for the number of times the compressor experiences low-pressure protection is incremented by 1, and the compressor is kept off and prevented from starting; if these conditions are not met, the preset shutdown detection logic is stopped.

[0014] In some implementations, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; the control unit executes a preset operation detection logic based on the currently recorded operating parameters of the air conditioning system; and during the execution of the preset operation detection logic, based on the range of the outdoor ambient temperature in the currently recorded parameters of the air conditioning system, it performs a categorized cumulative count of the number of times the compressor experiences low-pressure protection, obtaining a first type of cumulative count value and / or a second type of cumulative count value of the number of times the compressor experiences low-pressure protection, including: determining whether the following conditions are met: the currently recorded suction pressure value of the compressor is less than a first set pressure threshold within a continuous second set detection time, and the currently recorded outdoor ambient temperature of the air conditioning system is greater than a critical temperature set value; if met, the first type of cumulative count value of the number of times the compressor experiences low-pressure protection is incremented by 1, and the compressor is kept off and prohibited from being turned on; if not met, the second type of cumulative count value of the number of times the compressor experiences low-pressure protection is incremented by 1, and the compressor is kept off and prohibited from being turned on.

[0015] In some implementations, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; the control unit, after the compressor stops due to low pressure protection, combines the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low pressure protection, to control the compressor to automatically unlock the low pressure protection shutdown situation so that the compressor can resume operation, including: determining the sum of the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low pressure protection, and recording it as the total cumulative count value of the number of times the compressor has experienced low pressure protection; determining whether the total cumulative count value of the number of times the compressor has experienced low pressure protection is greater than or equal to a preset shutdown protection number threshold; if so, then based on the currently recorded outdoor ambient temperature of the air conditioning system... The system uses ambient temperature, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, to determine whether to display the low-pressure protection status of the compressor and automatically unlock the compressor from shutdown due to low-pressure protection, allowing the compressor to resume operation. The currently recorded outdoor ambient temperature of the air conditioning system is the temperature recorded after the total cumulative count of the number of times the compressor has experienced low-pressure protection minus one instance of low-pressure protection shutdown, and before the compressor restarts. If this condition is not met, the system uses the current continuous shutdown time of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection to automatically unlock the compressor from shutdown, allowing the compressor to resume operation.

[0016] In some implementations, the control unit determines whether to display a low-pressure protection status for the compressor and automatically unlock the compressor from a low-pressure protection shutdown state, based on the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the compressor's low-pressure protection occurrences. This allows the compressor to resume operation. The control unit includes: determining whether the currently recorded outdoor ambient temperature threshold setting for the air conditioning system is met; if so, displaying the low-pressure protection status and keeping the compressor off and preventing it from starting; if not, not displaying the low-pressure protection status and keeping the compressor off and preventing it from starting; and determining whether the currently recorded outdoor ambient temperature for the air conditioning system is greater than the threshold setting within a third consecutive set detection time; if so, clearing the second cumulative count of the compressor's low-pressure protection occurrences, and then determining whether the sum of the first and second cumulative counts of the compressor's low-pressure protection occurrences is less than a preset shutdown protection value. If the threshold for the number of times the compressor experiences low-pressure protection is not met, then it is determined whether the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor experiencing low-pressure protection is less than the preset shutdown protection threshold. If it is determined that the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor experiencing low-pressure protection is less than the preset shutdown protection threshold, then the display of the compressor experiencing low-pressure protection is cleared. Then, based on the current continuous shutdown time of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the compressor experiencing low-pressure protection, the compressor is controlled to automatically unlock the shutdown due to low-pressure protection, so that the compressor can resume operation. If it is determined that the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor experiencing low-pressure protection is greater than or equal to the preset shutdown protection threshold, then the process returns to display the compressor experiencing low-pressure protection, and keeps the compressor off and prevents the compressor from starting.

[0017] In some embodiments, the control unit, based on the compressor's current continuous downtime, the currently recorded compressor suction pressure value, the currently recorded outdoor ambient temperature of the air conditioning system, and a first type of cumulative count of the number of times the compressor has experienced low-pressure protection, and a second type of cumulative count of the number of times the compressor has experienced low-pressure protection, controls the compressor to automatically unlock from low-pressure protection to resume operation, thereby enabling the compressor to resume operation. This includes determining whether the following conditions are met: the compressor's current continuous downtime is greater than a set downtime, and the currently recorded compressor suction pressure value is greater than a second set pressure within a fourth consecutive set detection time; if these conditions are met, then the compressor is controlled to automatically unlock from low-pressure protection. To allow the compressor to resume operation, the system then adjusts the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, taking into account the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running. If the adjustment is not satisfied, the system returns to its previous state and continues to automatically unlock the compressor after it has experienced low-pressure protection and stopped, taking into account the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, so that the compressor can resume operation.

[0018] In some implementations, the control unit, in conjunction with the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has been started, adjusts the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection. This includes: determining whether the currently recorded outdoor ambient temperature of the air conditioning system is greater than a critical temperature setting value within a fifth consecutive set detection time; if so, clearing the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, and then determining whether the compressor has been started within a sixth consecutive detection time; if not, determining whether the compressor has been started within a sixth consecutive detection time; if it is determined that the compressor has been started within a sixth consecutive detection time, clearing both the first and second type of cumulative count values ​​of the number of times the compressor has experienced low-pressure protection, and then returning to re-record the operating parameters of the air conditioning system before the compressor was started; if it is determined that the compressor has not been started within a sixth consecutive detection time, returning to re-record the operating parameters of the air conditioning system before the compressor was started.

[0019] In conjunction with the above-described device, the present invention further provides an air conditioning system, comprising: the control device for the air conditioning system described above.

[0020] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device on which the storage medium is located controls the execution of the control method of the air conditioning system described above.

[0021] Therefore, the solution of the present invention, in the case where there is a long connecting pipe between the indoor and outdoor units in the air conditioning system (i.e., a connecting pipe where the installation distance between the indoor and outdoor units is greater than a set distance), when the entire air conditioning system is powered on and the air conditioning system controller has completed initialization, collects the outdoor ambient temperature and the low-pressure value of the compressor, and records the outdoor ambient temperature and the low-pressure value of the compressor before the compressor starts; determines whether the compressor has started running: if so, executes the preset compressor low-pressure protection operation detection logic; otherwise, executes the preset compressor low-pressure protection shutdown detection logic; and, when executing the preset compressor low-pressure protection operation detection logic or executing the preset... During the compressor low-pressure protection shutdown detection logic, the number of compressor low-pressure protection occurrences is cumulatively counted according to the outdoor ambient temperature range. Compressor low-pressure protection occurrences within the normal temperature range are counted in the first category, while those within the ultra-low temperature range are counted in the second category. Specifically, when executing the preset compressor low-pressure protection operation detection logic, it is determined whether the compressor's low-pressure value is continuously below the set pressure threshold and the outdoor ambient temperature is above the critical set temperature for a given period. If these conditions are met, the first category's cumulative count is incremented by 1, and the compressor remains shut down, prohibiting further pressure increases. The compressor starts, then checks if the sum of the first and second type of cumulative counts is less than a preset number of times. If not, the second type of cumulative count is incremented by 1, and the compressor remains off and is prevented from starting. Then, it checks if the sum of the first and second type of cumulative counts is less than a preset number of times. When executing the preset compressor low-pressure protection shutdown detection logic, it checks if the following conditions are met: the compressor continuous shutdown time exceeds the set shutdown time; the compressor's low-pressure value is detected to be less than the set pressure threshold for a continuous period; and the outdoor ambient temperature is greater than the critical temperature setting. If these conditions are met, the compressor low-pressure protection is displayed, the first type of cumulative count is incremented by 1, and the compressor remains off and is prevented from starting. The compressor remains off and is prevented from starting. Then, it is determined whether the sum of the cumulative counts for the first and second categories is less than a preset number of times. If not, no display is shown and no low-pressure compressor detection is performed. The system then returns to determine if the following conditions are met: the compressor's continuous shutdown time exceeds the set shutdown time; the compressor's low-pressure value is detected as less than the set pressure threshold for a continuous period; and the outdoor ambient temperature is greater than the critical temperature setting. After determining whether the sum of the cumulative counts for the first and second categories is less than a preset number of times: if the conditions are met, it is determined whether the compressor can resume automatic operation based on the compressor's continuous running time and the compressor's low-pressure value for a period of time.If the conditions are not met, the system determines whether the compressor low-pressure protection is activated based on the outdoor ambient temperature before the compressor starts following the previous low-pressure protection activation. This ensures that the compressor, after being locked due to low-pressure protection, cannot automatically resume operation. Under normal operating temperature conditions, it can automatically unlock and resume normal operation without manual reset or power interruption restart. Therefore, by categorizing and cumulatively counting the number of compressor low-pressure protection activations based on the outdoor ambient temperature range, and combining the outdoor ambient temperature with the total cumulative count of compressor low-pressure protection activations, the system determines whether the compressor will automatically resume operation after being locked due to low-pressure protection. This ensures timely and effective execution of compressor low-pressure protection, while preventing excessive accumulation of low-pressure protection activations that could lead to compressor lockup and inability to automatically resume operation. This effectively reduces manual intervention and lowers maintenance costs.

[0022] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0023] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating an embodiment of the control method for an air conditioning system according to the present invention;

[0025] Figure 2 This is a flowchart illustrating an embodiment of the method of the present invention, which executes shutdown detection logic when the compressor is not turned on and obtains a first type of cumulative count value and / or a second type of cumulative count value of the number of times the compressor has experienced low-pressure protection.

[0026] Figure 3 This is a flowchart illustrating an embodiment of the method of the present invention, in which the operation detection logic is executed when the compressor is turned on to obtain a first type of cumulative count value and / or a second type of cumulative count value of the number of times the compressor has experienced low-pressure protection.

[0027] Figure 4 This is a flowchart illustrating an embodiment of the method of the present invention, which combines a first type of cumulative count value and / or a second type of cumulative count value of the number of times the compressor experiences low-pressure protection to control the compressor to unlock and resume operation.

[0028] Figure 5 This is a schematic flowchart of an embodiment of the method of the present invention, in which the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor low-pressure protection number is greater than or equal to a preset shutdown protection number threshold.

[0029] Figure 6This is a schematic flowchart of an embodiment of the method of the present invention, in which the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor low-pressure protection is less than a preset shutdown protection count threshold;

[0030] Figure 7 This is a flowchart illustrating an embodiment of the method of the present invention, which adjusts the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor experiences low-pressure protection after the compressor is unlocked and resumes operation.

[0031] Figure 8 This is a schematic diagram of the structure of an embodiment of the control device for the air conditioning system of the present invention;

[0032] Figure 9 This is a flowchart illustrating an embodiment of a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split system) according to the present invention.

[0033] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0034] 102 - Acquisition unit; 104 - Control unit. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] The compressor's technical specifications typically outline the compressor's technical parameters, such as rated power, rated current, rated voltage, motor speed, frequency range, oil return frequency range, applicable refrigerant, and applicable suction and discharge pressure ranges. Under normal circumstances, the compressor should operate in accordance with the parameters specified in the technical specifications after startup; otherwise, damage to the compressor may occur.

[0037] Air conditioning systems (such as computer room air conditioning or other large multi-split systems) are widely used in data center construction. After the air conditioning system is installed and debugged, there are few maintenance personnel on site to monitor the operation of the unit (i.e. the unit where the air conditioning system is located) in real time. Moreover, the core computer room area has extremely high requirements for environmental temperature and humidity control. Once the unit compressor is damaged and cannot be repaired in time, it is very easy to cause server downtime, resulting in unpredictable risks and losses.

[0038] Considering that if the low-pressure protection of the air conditioning system's compressor is not timely, it can easily damage the compressor. However, unlimited low-pressure protection means that the compressor will operate in an unreliable low-pressure range an unlimited number of times, which can easily damage the compressor.

[0039] In the relevant solutions, the control logic for low-pressure protection of the compressor in the air conditioning system is as follows: when the cumulative number of low-pressure protection events is less than 6, if the compressor runs continuously for more than 6 minutes after starting, it indicates that the compressor can start and run normally, and the cumulative number of low-pressure protection events is cleared. If the compressor continues to experience low-pressure protection after a cumulative total of 6 or more events, the compressor will be locked and cannot be started. Manual reset or a complete power-off restart is required to restore normal operation, which is inconvenient to use.

[0040] Furthermore, after the compressor starts, adjusting the opening of the electronic expansion valve or the compressor operating frequency (the frequency of a fixed-frequency compressor cannot be adjusted) based on changes in the compressor's discharge temperature or the evaporator inlet and outlet pipe temperatures is complex and prone to causing the compressor to operate with liquid, leading to wear. It also fails to effectively address the low-pressure protection issue of the compressor in ultra-low outdoor temperatures under long-connected pipe conditions between the indoor and outdoor units. During the overall operation of the air conditioning system, temperature changes such as compressor discharge temperature or evaporator inlet and outlet pipe temperatures typically exhibit a certain lag. Under long-connected pipe conditions, it is difficult for the refrigerant to quickly establish effective circulation after the compressor has been running for a period of time. For example, in cases of long-connected pipe conditions between the indoor and outdoor units, theoretically, the discharge temperature will rise after the compressor starts because the refrigerant has not yet effectively established circulation. According to the control logic in the relevant scheme, the electronic expansion valve should be opened wider to ensure refrigerant flow. However, once the refrigerant actually reaches the electronic expansion valve, the excessively large opening of the valve may cause the compressor to operate with liquid, leading to compressor wear.

[0041] Furthermore, in engineering installation, adding a low-temperature start-up component to preheat the refrigerant accumulation side under ultra-low temperature conditions can effectively solve the compressor low-pressure protection problem, but the cost is too high. The low-temperature start-up component is designed to preheat the refrigerant under low-temperature conditions to enhance its fluidity, which facilitates the rapid establishment of an effective cycle and thus avoids compressor low-pressure protection.

[0042] It is evident that during the operation of an air conditioning system, if compressor low-pressure protection occurs, it must activate. However, frequent occurrences of compressor low-pressure protection are unacceptable. The reason for locking the compressor after frequent low-pressure protection is to prevent compressor damage. Therefore, compressor low-pressure protection must be executed promptly and effectively, and not indefinitely, to avoid compressor damage. Conversely, limiting the number of times compressor low-pressure protection can lead to compressor locking and inability to automatically resume operation. This requires manual intervention to reset the unit or a power outage and re-energization before normal operation can resume. These two aspects are contradictory, yet both must be balanced. Furthermore, some solutions control the opening of the electronic expansion valve by detecting changes in compressor exhaust temperature or evaporator inlet and outlet pipe temperatures to minimize compressor low-pressure protection. However, in practice, it is difficult to ensure the reliability of compressor operation under all operating conditions.

[0043] Therefore, the present invention proposes a control method for an air conditioning system, specifically a compressor low-pressure protection control method for an air conditioning system. The compressor low-pressure protection under different conditions is classified and handled flexibly after classification, so as to avoid the compressor from locking up due to frequent low-pressure protection. This avoids complex control logic design and eliminates the need for low-temperature components in engineering.

[0044] According to embodiments of the present invention, a control method for an air conditioning system is provided, such as... Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. A long connecting pipe connects the indoor and outdoor units of the air conditioning system. The control method of the air conditioning system includes steps S110 to S150.

[0045] In step S110, after the air conditioning system is powered on, specifically when the entire unit of the air conditioning system is powered on and the controller of the air conditioning system has completed initialization, the outdoor ambient temperature of the air conditioning system (e.g., outdoor ambient temperature OUTtemp) is collected, and the suction pressure value of the compressor in the air conditioning system (e.g., low pressure value Clowpress) is collected; the operating parameters of the air conditioning system before the compressor starts are recorded; if the compressor shuts down due to low pressure protection, the operating parameters of the air conditioning system before the compressor starts are recorded again. Specifically, Figure 9 This is a flowchart illustrating an embodiment of a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split system) according to the present invention. Figure 9As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split system), comprising: Step 01, after the air conditioning system (such as a computer room air conditioner or other large multi-split system) is powered on, the controller completes initialization and begins to collect outdoor ambient temperature OUTtemp and compressor low-pressure value ClowPress in real time, and collects and records outdoor ambient temperature OUTtemp and low-pressure value Clowpress in real time before the compressor starts; after the compressor starts, the recorded values ​​of outdoor ambient temperature OUTtemp and low-pressure value Clowpress remain unchanged; after the compressor is turned off, outdoor ambient temperature OUTtemp and low-pressure value Clowpress are re-recorded in real time, and then step 02 is executed.

[0046] In step S120, it is determined whether the compressor has been turned on. Specifically, as follows: Figure 9 As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes: Step 02, determining whether the compressor is running: if the compressor is not running, performing a compressor low-pressure protection shutdown detection, and proceeding to Step 03; if the compressor is running, performing a compressor low-pressure protection operation detection, and proceeding to Step 04. Figure 9 In the compressor low-pressure protection control process of the air conditioning system (such as computer room air conditioning or other large multi-split system) shown, the compressor low-pressure protection is divided into compressor shutdown detection and compressor operation detection.

[0047] Whether the compressor starts or runs is determined by the air conditioning unit's controller program, which executes start and stop commands based on set parameters. If the air conditioning unit is running and the temperature conditions for starting the compressor are met, and there are no other limiting conditions affecting compressor operation, the compressor will start. Conversely, if the temperature conditions for shutting down the compressor are met, or if other limiting conditions affect compressor operation, the compressor will shut down.

[0048] In step S130, if it is determined that the compressor is not turned on, when performing low-pressure protection on the compressor, a preset shutdown detection logic is executed based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system. During the execution of the preset shutdown detection logic, the number of times the compressor experiences low-pressure protection is cumulatively counted according to the outdoor ambient temperature range in the currently recorded parameters of the air conditioning system, resulting in a first type of cumulative count value and / or a second type of cumulative count value. The first type of cumulative count value is such as NUMA, and the second type of cumulative count value is such as NUMB. Specifically, as shown... Figure 9As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split systems), which further includes: step 03, performing compressor low-pressure protection shutdown detection. The compressor shutdown detection is to detect whether there is refrigerant leakage after the entire air conditioning system has been shut down and left undisturbed for a long time (e.g., several days or even several months). At the same time, it must not falsely report low-pressure protection. Therefore, the solution is to not detect compressor low-pressure protection when the outdoor ambient temperature OUTtemp < -30℃, because under extremely low temperature conditions, the refrigerant's gaseous or near-liquid state results in very low expansion pressure within the pipeline.

[0049] In some embodiments, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; in step S130, when the compressor is not turned on, when the compressor is under low-pressure protection, a preset shutdown detection logic is executed based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system; and during the execution of the preset shutdown detection logic, the number of times the compressor underwent low-pressure protection is cumulatively counted according to the range of the outdoor ambient temperature in the currently recorded parameters of the air conditioning system, and the specific process of obtaining the first type of cumulative count value and / or the second type of cumulative count value of the number of times the compressor underwent low-pressure protection is obtained is described in the following exemplary description.

[0050] The following is combined Figure 2 The illustrated flowchart shows an embodiment of the method of the present invention in which the shutdown detection logic is executed when the compressor is not turned on and the first type of cumulative count value and / or the second type of cumulative count value of the number of times the compressor has experienced low pressure protection is obtained. The specific process of executing the shutdown detection logic and obtaining the first type of cumulative count value and / or the second type of cumulative count value of the number of times the compressor has experienced low pressure protection in step S130 is further explained, including steps S210 to S230.

[0051] Step S210: When the compressor is not turned on, and low-pressure protection is applied to the compressor, determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time; the currently recorded suction pressure value of the compressor within a continuous first set detection time is less than a first set pressure threshold; and the currently recorded outdoor ambient temperature of the air conditioning system is greater than a set outdoor ambient temperature threshold. Wherein, the set shutdown time is, for example, 3 minutes; the first set detection time is, for example, Time2; the first set pressure threshold is, for example, 150 kPa; and the set outdoor ambient temperature threshold is, for example, -30°C.

[0052] Step S220: If satisfied, the low-pressure protection status of the compressor is displayed, the first type of cumulative count of the number of times the compressor has experienced low-pressure protection is incremented by 1, and the compressor is kept off and prevented from starting. Then, after executing the preset shutdown detection logic and / or the preset operation detection logic, and after obtaining the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and / or the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, if the compressor stops due to low-pressure protection, then after the compressor stops due to low-pressure protection, based on the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, the compressor is controlled to automatically unlock the low-pressure protection shutdown status so that the compressor can resume operation.

[0053] Step S230: If the conditions are not met, the execution of the preset shutdown detection logic is stopped, and the process returns to re-record the operating parameters of the air conditioning system before the compressor starts. That is, if the conditions are not met, the low-pressure protection status of the compressor is not displayed, and when the compressor is not running, the preset shutdown detection logic is not executed based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system during low-pressure protection, and the process returns to re-record the operating parameters of the air conditioning system before the compressor starts.

[0054] Specifically, such as Figure 9 As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split systems), which further includes: in step 03, when performing compressor low-pressure protection shutdown detection, determining whether the compressor continuous shutdown time is more than 3 minutes, and whether the compressor low-pressure value Clowpress < 150 kPa is detected for a continuous Time2 time (e.g., 15s to 60s), and whether the outdoor ambient temperature OUTtemp > -30°C.

[0055] If the compressor is continuously shut down for more than 3 minutes, and the low pressure value of the compressor (Clowpress) is detected to be <150 kPa for a continuous Time2 period, and the outdoor ambient temperature (OUTtemp) is >30°C, then the compressor low pressure protection will be displayed, the cumulative number of compressor low pressure protection calls (NUMA) will be incremented by 1, the compressor will remain off, and starting will be prohibited.

[0056] Conversely, if the following conditions are not met: the compressor has been continuously stopped for more than 3 minutes, and the low pressure value detected for Time2 is <150KPa, and the outdoor ambient temperature OUTtemp is >-30℃, then the compressor low pressure protection will not be displayed or detected, and step 05 will be executed again.

[0057] The compressor shutdown detection, under normal circumstances, involves the air conditioning system being installed and commissioned. The system is pre-charged with the required amount of refrigerant according to technical specifications. When the unit is powered on, the controller can monitor various parameters in real time, such as evaporator inlet and outlet pipe temperatures, exhaust temperature, outdoor ambient temperature, suction pressure, and condensing pressure. With the compressor off, the system uses the detected suction pressure to determine if there is a refrigerant leak. For example, under normal refrigerant charge conditions, the compressor suction pressure is approximately between 1000 kPa and 1500 kPa at room temperature. If the detected suction pressure is very low, such as below 150 kPa, it is determined to be a refrigerant shortage.

[0058] In step S140, if it is determined that the compressor has been turned on, then when performing low-pressure protection on the compressor, a preset operation detection logic is executed according to the currently recorded operating parameters of the air conditioning system; and during the execution of the preset operation detection logic, the number of times the compressor experiences low-pressure protection is cumulatively counted according to the outdoor ambient temperature range in the currently recorded parameters of the air conditioning system, resulting in a first type of cumulative count value and / or a second type of cumulative count value for the number of times the compressor experiences low-pressure protection. Specifically, as shown... Figure 9 As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split systems), which further includes: Step 04, performing compressor low-pressure protection operation detection. Compressor operation detection is to check whether the compressor intake and exhaust meet normal operating conditions (i.e., whether the relevant technical parameters meet the requirements in the compressor technical specifications) during the overall operation of the air conditioning system. During compressor operation, if there is pipe blockage, insufficient refrigerant, load damage or abnormal wiring leading to uncontrolled load, or compressor reversal due to electrical wiring errors, the compressor intake pressure (i.e., low-pressure) may become extremely low, exceeding the normal operating range. If protection is not implemented in time, it can easily damage the compressor.

[0059] In some embodiments, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; in step S140, when the compressor is turned on and low-pressure protection is applied to the compressor, a preset operation detection logic is executed according to the currently recorded operating parameters of the air conditioning system; and during the execution of the preset operation detection logic, the number of times the compressor experiences low-pressure protection is cumulatively counted according to the range of the outdoor ambient temperature in the currently recorded parameters of the air conditioning system, and the specific process of obtaining the first type of cumulative count value and / or the second type of cumulative count value of the number of times the compressor experiences low-pressure protection is applied is described in the following exemplary description.

[0060] The following is combined Figure 3 The illustrated flowchart shows an embodiment of the method of the present invention in which the operation detection logic is executed when the compressor is turned on and the first type of cumulative count value and / or the second type of cumulative count value of the number of times the compressor has experienced low pressure protection is obtained. The specific process of executing the operation detection logic and obtaining the first type of cumulative count value and / or the second type of cumulative count value of the number of times the compressor has experienced low pressure protection in step S140 is further explained, including steps S310 to S330.

[0061] Step S310: When the compressor is turned on, during low-pressure protection of the compressor, determine whether the following conditions are met: the suction pressure value of the compressor currently recorded within a continuous second set detection time is less than the first set pressure threshold, and the outdoor ambient temperature of the air conditioning system currently recorded is greater than the critical temperature set value. Wherein, the second set detection time is, for example, Time1 time, the first set pressure threshold is, for example, 150 kPa, and the critical temperature set value is, for example, Tset.

[0062] Step S320: If satisfied, increment the first type of cumulative count value of the number of times the compressor has experienced low-pressure protection by 1, keep the compressor off and prevent it from starting. Then, after executing the preset shutdown detection logic and / or the preset operation detection logic, and after obtaining the first type of cumulative count value of the number of times the compressor has experienced low-pressure protection and / or the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, if the compressor stops due to low-pressure protection, then after the compressor stops due to low-pressure protection, based on the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, control the compressor to automatically unlock the low-pressure protection shutdown situation so that the compressor can resume operation.

[0063] Step S330: If the condition is not met, increment the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection by 1, keep the compressor off and prevent it from starting. Then, after executing the preset shutdown detection logic and / or the preset operation detection logic, and after obtaining the first type of cumulative count value of the number of times the compressor has experienced low-pressure protection and / or the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, if the compressor stops due to low-pressure protection, then after the compressor stops due to low-pressure protection, combine the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, control the compressor to automatically unlock the low-pressure protection shutdown situation so that the compressor can resume operation.

[0064] Specifically, such as Figure 9 As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes: in step 04, when performing compressor low-pressure protection operation detection, determining whether the following conditions are met: the compressor low-pressure value Clowpress < 150 kPa is detected continuously for Time1, and the outdoor ambient temperature OUTtemp > the critical set temperature Tset.

[0065] If the compressor is already running and the low pressure value Clowpress < 150 kPa is detected for a continuous Time1 period, when the outdoor ambient temperature OUTtemp > the critical set temperature Tset, the compressor low pressure protection cumulative count NUMA is incremented by 1, the compressor remains off and is prohibited from starting, and then step 05 is executed.

[0066] Conversely, when the outdoor ambient temperature OUTtemp ≤ the critical temperature setpoint Tset, the cumulative number of low-pressure protection cycles for the compressor NUMB is incremented by 1, the compressor remains off and is prohibited from being turned on, and then step 05 is executed.

[0067] The compressor operation detection involves continuously detecting a suction pressure of less than 150 kPa within a certain period after the compressor is started, which indicates low-pressure protection. Common causes of low-pressure protection include refrigerant shortage, obstructed piping leading to abnormal refrigerant circulation, or excessively long piping preventing the establishment of effective refrigerant circulation within a short time.

[0068] Additionally, Time1 should not exceed 2 minutes, such as 30s to 60s. The aforementioned -30℃ is used to determine whether the compressor low-pressure protection detected when the compressor is stopped should be displayed. The critical set temperature Tset is used to distinguish between the cumulative number of faults A and the cumulative number of faults B.

[0069] In step S150, after executing the preset shutdown detection logic and / or the preset operation detection logic, and after obtaining the first type of cumulative count value and / or the second type of cumulative count value of the compressor's low-pressure protection occurrences, if the compressor shuts down due to low-pressure protection, then after the compressor shuts down due to low-pressure protection, based on the compressor's current continuous shutdown time, the currently recorded operating parameters of the air conditioning system, and the first and second type of cumulative count values ​​of the compressor's low-pressure protection occurrences, the compressor's shutdown due to low-pressure protection is automatically unlocked to allow the compressor to resume operation. Here, the compressor's current continuous shutdown time is the shutdown time since the compressor's last shutdown after the air conditioning system is powered on. Specifically, as... Figure 9 As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split systems), which further includes: classifying compressor low-pressure protection under different conditions, specifically classifying the cumulative number of compressor low-pressure protections according to the range of outdoor ambient temperature OUTtemp into cumulative number A (i.e., NUMA) and cumulative number B (i.e., NUMB). NUMA represents the cumulative number of protections within a stable temperature range, which is generally unlikely to occur under normal circumstances; its occurrence indicates a genuine abnormality in the unit's operation. NUMB represents the cumulative number of protections within an unstable temperature range, which is generally affected by the length of the connecting pipe between the indoor and outdoor units and the compressor's performance, and is more likely to occur under extremely low temperatures, but its occurrence does not necessarily indicate a abnormality in the unit's operation. The compressor's outdoor ambient temperature OUTtemp can be automatically reset to zero when it rises above the critical set temperature Tset. Related solutions do not distinguish between the types of cumulative low-pressure protection counts for compressors. However, the solution of this invention requires differentiation. For example, based on the range of the outdoor ambient temperature OUTtemp of the compressor, the cumulative low-pressure protection counts can be divided into cumulative counts A (i.e., NUMA) and cumulative counts B (i.e., NUMB). In this way, by classifying the compressor low-pressure protection under different conditions, the compressor low-pressure protection can be flexibly handled after classification, so as to avoid the compressor from locking up due to frequent low-pressure protection. This avoids complex control logic design and eliminates the need for low-temperature components in engineering.

[0070] This invention proposes a compressor low-pressure protection control method for an air conditioning system. The method categorizes the cumulative number of compressor low-pressure protection calls based on the outdoor ambient temperature range of the air conditioning system. When the cumulative number of low-pressure protection calls reaches 12 or more, the compressor remains shut down and is not allowed to start. The method then determines whether to display compressor low-pressure protection based on the outdoor ambient temperature before the last compressor start-up. When the outdoor ambient temperature rises above the critical set temperature, the cumulative number of compressor low-pressure protection calls in the ultra-low temperature range is automatically cleared, allowing the compressor to unlock and automatically resume operation. This categorizes compressor low-pressure protection under different conditions, enabling flexible handling and minimizing the risk of the compressor locking up due to frequent low-pressure protection. This avoids complex control logic design and eliminates the need for low-temperature components in engineering.

[0071] In some implementations, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; in step S150, after executing the preset shutdown detection logic and / or executing the preset operation detection logic, and after obtaining the first type of cumulative count value of the number of times the compressor has experienced low-pressure protection and / or the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, if the compressor stops due to low-pressure protection, then after the compressor stops due to low-pressure protection, the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection are combined to control the automatic unlocking of the compressor's low-pressure protection shutdown situation so that the compressor can resume operation. For the specific process, please refer to the following exemplary description.

[0072] The following is combined Figure 4 The schematic diagram of an embodiment of the method of the present invention, which combines the first type of cumulative count value and / or the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, is shown. The specific process of controlling the compressor to unlock and resume operation by combining the first type of cumulative count value and / or the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection in step S150 is further explained, including steps S410 to S430.

[0073] Step S410: Determine the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor's low-pressure protection occurrences, and record it as the total cumulative count value of the compressor's low-pressure protection occurrences; determine whether the following condition is met: the total cumulative count value of the compressor's low-pressure protection occurrences is greater than or equal to a preset shutdown protection number threshold. The preset shutdown protection number threshold is, for example, 12 times.

[0074] Step S420: If satisfied, then if the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is greater than or equal to the preset shutdown protection threshold, based on the currently recorded outdoor ambient temperature of the air conditioning system and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, determine whether to display the low-pressure protection situation of the compressor and control the compressor to automatically unlock the shutdown situation caused by low-pressure protection so that the compressor can resume operation; wherein, the currently recorded outdoor ambient temperature of the air conditioning system is the outdoor ambient temperature of the air conditioning system recorded after the total cumulative count of the number of times the compressor has experienced low-pressure protection minus 1 time the compressor has experienced low-pressure protection and shut down, and before the compressor is restarted.

[0075] Step S430: If the condition is not met, then if the sum of the first type of cumulative count of the number of times the compressor has low-pressure protection and the second type of cumulative count of the number of times the compressor has low-pressure protection is less than the preset shutdown protection threshold, then based on the current continuous shutdown time of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count of the number of times the compressor has low-pressure protection and the second type of cumulative count of the number of times the compressor has low-pressure protection, the compressor will be automatically unlocked to allow the compressor to resume operation.

[0076] Specifically, such as Figure 9 As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes:

[0077] Step 05: After the compressor stops due to low pressure protection, determine whether the sum of the cumulative number of low pressure protection calls NUMA and NUMB is ≥12. If not, determine whether the compressor can resume automatic operation and proceed to step 06. If it is satisfied, determine whether the compressor low pressure protection is displayed and proceed to step 07.

[0078] Referring to the example shown in step 05, the principle for distinguishing the cumulative number of compressor low-pressure protection events is as follows: The cumulative number of low-pressure protection events is divided into cumulative number A (NUMA) and cumulative number B (NUMB) based on the range of the outdoor ambient temperature OUTtemp of the compressor. Record the outdoor ambient temperature OUTtemp before the compressor starts running. If low-pressure protection occurs after the compressor starts running, determine whether the low-pressure protection is classified as cumulative number A or cumulative number B based on the recorded outdoor ambient temperature OUTtemp. For example, if the outdoor ambient temperature before the compressor starts is below -25℃, low-pressure protection after the compressor starts is recorded as cumulative number B; conversely, if the outdoor ambient temperature is above -25℃, low-pressure protection is recorded as cumulative number A.

[0079] The critical temperature value Tset can be set according to actual needs. Specifically, the critical low temperature start-up temperature value can be reasonably set according to the length of the connecting pipe between the indoor and outdoor units and the climate characteristics of the location of use. This can maximize the safe start-up of the compressors of different units and maximize the accuracy of timely on-site temperature and humidity control.

[0080] Step 06: If the sum of the cumulative number of low-pressure protection calls (NUMA and NUMB) is less than 12, determine whether the compressor should automatically resume operation.

[0081] Step 07: If the cumulative number of compressor low-pressure protection calls is ≥12, determine whether to display compressor low-pressure protection.

[0082] In some embodiments, in step S420, if the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is greater than or equal to a preset shutdown protection threshold, the system determines whether to display the low-pressure protection status of the compressor and controls the compressor to automatically unlock the shutdown status due to low-pressure protection, based on the currently recorded outdoor ambient temperature of the air conditioning system and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, so as to restore the compressor to operation. For the specific process, please refer to the following exemplary description.

[0083] The following is combined Figure 5The illustrated flowchart shows an embodiment of the method of the present invention in which the compressor is unlocked and resumed operation when the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor low-pressure protection occurrence is greater than or equal to a preset shutdown protection occurrence threshold. The flowchart further illustrates the specific process of controlling the compressor to unlock and resume operation when the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor low-pressure protection occurrence is greater than or equal to the preset shutdown protection occurrence threshold in step S420, including steps S510 to S540.

[0084] Step S510: If the sum of the first type of cumulative count of the number of times the compressor experiences low-pressure protection and the second type of cumulative count of the number of times the compressor experiences low-pressure protection is greater than or equal to a preset shutdown protection threshold, determine whether the currently recorded outdoor ambient temperature critical temperature setting value of the air conditioning system is met. If it is met, the low-pressure protection status of the compressor is displayed, and the compressor is kept off and prohibited from starting. If it is not met, the low-pressure protection status of the compressor is not displayed, and the compressor is kept off and prohibited from starting. The currently recorded outdoor ambient temperature of the air conditioning system is the outdoor ambient temperature of the air conditioning system recorded after the total cumulative count of the number of times the compressor experiences low-pressure protection minus one instance of low-pressure protection causing shutdown, and before the compressor restarts.

[0085] Step S520: Determine whether the outdoor ambient temperature of the air conditioning system currently recorded within the third consecutive set detection time is greater than the critical temperature set value. If so, clear the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection. Then, determine whether the sum of the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection is less than the preset shutdown protection number threshold. If not, determine whether the sum of the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection is less than the preset shutdown protection number threshold. The third set detection time is, for example, Time4.

[0086] Step S530: If the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than a preset shutdown protection threshold, then the display of the compressor's low-pressure protection status is cleared. That is, if the compressor's low-pressure protection status has already been displayed, the display is cleared; if the compressor's low-pressure protection status has not been displayed, the display remains closed. Then, if the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than the preset shutdown protection threshold, based on the compressor's current continuous shutdown time, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, the compressor is automatically unlocked to allow it to resume operation.

[0087] Step S540: If the sum of the first type of cumulative count value of the number of times the compressor has low-pressure protection and the second type of cumulative count value of the number of times the compressor has low-pressure protection is greater than or equal to the preset shutdown protection number threshold, then return to display the low-pressure protection situation of the compressor, keep the compressor off and prevent the compressor from starting.

[0088] Specifically, such as Figure 9 As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes:

[0089] In step 07, if the cumulative number of compressor low-pressure protection calls is ≥12, then it checks whether the outdoor ambient temperature OUTtemp before the compressor starts after the 11th low-pressure protection call is greater than the critical temperature setting Tset. If it is, the compressor low-pressure protection is displayed, the compressor remains off, and starting is prohibited. If it is not, the compressor low-pressure protection is not displayed, the compressor remains off, and starting is prohibited, then proceed to step 08. Displaying a fault message can easily cause user anxiety and unnecessary tension. In the solution of this invention, low-pressure protection is only displayed under specific low-pressure protection conditions. If factors such as excessively low outdoor ambient temperature could easily lead to false low-pressure protection alarms, low-pressure protection is not displayed.

[0090] Step 08: When the outdoor ambient temperature OUTtemp is detected to be greater than the critical temperature setpoint Tset for a continuous Time4 period (e.g., 1min to 5min), the cumulative count NUMB is cleared. If the sum of the compressor low-pressure protection counts NUMA and NUMB is less than 12 times, the compressor low-pressure protection display is cleared, and then the process is repeated as in step 06.

[0091] In some embodiments, in steps S430 and S530, if the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than a preset shutdown protection threshold, the compressor is automatically unlocked due to low-pressure protection and shutdown, based on the compressor's current continuous shutdown time, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, so as to restore the compressor's operation. For the specific process, please refer to the following exemplary description.

[0092] The following is combined Figure 6 The illustrated flowchart shows an embodiment of the method of the present invention in which the compressor is unlocked and resumed operation when the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor's low-pressure protection occurrences is less than a preset shutdown protection occurrence threshold. The flowchart further illustrates the specific process of controlling the compressor to unlock and resume operation when the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor's low-pressure protection occurrences is less than the preset shutdown protection occurrence threshold in steps S430 and S530, including steps S610 to S630.

[0093] Step S610: If the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than a preset shutdown protection threshold, determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, and the currently recorded suction pressure value of the compressor within the fourth consecutive set detection time is greater than the second set pressure. Wherein, the second set pressure is, for example, 250 kPa, and the fourth set detection time is, for example, Time3.

[0094] Step S620: If the condition is met, the compressor is automatically unlocked when it stops due to low pressure protection, so that the compressor can resume operation. Then, based on the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running, the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low pressure protection are adjusted.

[0095] Step S630: If not satisfied, return to continue executing the preset shutdown detection logic and / or the preset operation detection logic. After obtaining the first type of cumulative count value of the number of times the compressor has experienced low-pressure protection and / or the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, if the compressor stops due to low-pressure protection, then after the compressor stops due to low-pressure protection, based on the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, control the compressor to automatically unlock the low-pressure protection shutdown situation so that the compressor can resume operation.

[0096] Specifically, such as Figure 9 As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes: in step 06, if the sum of the cumulative number of compressor low-pressure protection NUMA and NUMB is less than 12 times, and the compressor has been continuously stopped for more than 3 minutes, and the low-pressure value detected for a continuous Time3 period (such as 15s to 30s) is greater than 250KPa, the compressor automatically resumes operation, and then the process proceeds to step 09.

[0097] In some implementations, step S620 involves automatically unlocking the compressor when it shuts down due to low-pressure protection, allowing the compressor to resume operation. The specific process of adjusting the first type of cumulative count of the number of times the compressor has experienced low-pressure protection, taking into account the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running, is described in the following exemplary description.

[0098] The following is combined Figure 7 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention, which adjusts the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has low pressure protection after the compressor is unlocked and resumed operation. It further illustrates the specific process of adjusting the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has low pressure protection after the compressor is unlocked and resumed operation in step S620, including steps S710 to S730.

[0099] Step S710: Determine whether the outdoor ambient temperature of the air conditioning system currently recorded within the fifth consecutive set detection time is greater than the critical temperature set value. If it is satisfied, clear the second type of cumulative count value of the number of times the compressor has low pressure protection. Then determine whether the compressor has been turned on and running within the sixth consecutive detection time. If it is not satisfied, determine whether the compressor has been turned on and running within the sixth consecutive detection time.

[0100] Step S720: If it is determined whether the compressor has been turned on and running within the sixth consecutive detection time, then clear the first type of cumulative count value of the number of times the compressor has encountered low pressure protection, and clear the second type of cumulative count value of the number of times the compressor has encountered low pressure protection, and then return to record the operating parameters of the air conditioning system before the compressor is turned on again.

[0101] Step S730: If it is determined that the compressor has not been turned on during the sixth consecutive detection time, return to the previous step to re-record the operating parameters of the air conditioning system before the compressor was turned on.

[0102] Specifically, such as Figure 9 As shown, the present invention proposes a compressor low-pressure protection control method for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes:

[0103] Step 09: If the outdoor ambient temperature OUTtemp is detected to be greater than the critical temperature setpoint Tset for a continuous Time 5 time period (e.g., 1 min to 5 min), clear the accumulated count NUMB and then proceed to step 10. If the outdoor ambient temperature OUTtemp is detected to be greater than the critical temperature setpoint Tset for a continuous Time 5 time period, proceed directly to step 10.

[0104] Step 10: If the compressor starts running and is continuously detected to be running for a continuous Time6 period (e.g., 3 min to 6 min), then clear the accumulated counts NUMA and NUMB, and return to step 01 for execution, repeating the process. Referring to the examples shown in steps 06 to 10, in the solution of this invention, the type of accumulated count for compressor low-pressure protection is distinguished based on the outdoor ambient temperature OUTtemp range, divided into accumulated counts NUMA for the normal temperature range and accumulated counts NUMB for the ultra-low temperature range. When the sum of the two reaches 12 or more, the compressor remains off and is prohibited from starting. When the outdoor ambient temperature OUTtemp rises above the critical set temperature Tset, the accumulated counts NUMB for compressor low-pressure protection in the ultra-low temperature range are automatically cleared, making the sum of the accumulated counts less than 12, thereby unlocking the compressor and automatically resuming operation. In this way, the compressor cannot automatically resume operation after being locked due to low pressure protection. Under normal operating temperature conditions, it can automatically unlock and resume normal operation without manual reset or power failure restart. Thus, it can effectively and timely implement compressor low pressure protection, and also avoid the compressor being locked due to excessive accumulation of low pressure protection, which can effectively reduce manual intervention and lower operation and maintenance costs.

[0105] Referring to the examples shown in steps 01 to 10, in the solution of this invention, after the compressor experiences low-pressure protection, the cumulative number of compressor low-pressure protection calls (NUMA and NUMB) is calculated according to the range of the compressor's outdoor ambient temperature (OUTtemp). When the sum of the cumulative numbers of NUMA and NUMB is greater than or equal to 12, the outdoor ambient temperature (OUTtemp) before the 12th low-pressure protection call is used to determine whether to display compressor low-pressure protection and whether to lock the compressor so that it cannot automatically resume operation. When the outdoor ambient temperature (OUTtemp) rises to a critical temperature value (Tset) or higher, the cumulative number of calls (NUMB) is reset to zero, making the sum of the cumulative numbers less than 12, thus removing the restriction that the compressor cannot automatically resume operation due to low-pressure protection. Alternatively, after the compressor experiences low-pressure protection, the cumulative number of compressor low-pressure protection calls (NUMA and NUMB) is calculated according to the range of the compressor's outdoor ambient temperature (OUTtemp). If the sum of the cumulative numbers of NUMA and NUMB is less than 12, and the compressor can run normally for more than 5 minutes, then the cumulative number of compressor low-pressure protection calls (NUMA and NUMB) is reset to zero, and the compressor low-pressure protection call count is re-detected and accumulated.

[0106] In particular, due to the influence of ultra-low temperature environments, the refrigerant has poor fluidity based on the principle of thermal expansion and contraction. If combined with actual engineering conditions, such as long pipe connections between indoor and outdoor units, it is difficult to establish effective refrigerant circulation after the compressor is turned on. In this case, compressor low-pressure protection is prone to occur. By distinguishing and recording the cumulative number of compressor low-pressure protections based on the range of outdoor ambient temperature OUTtemp, the low-pressure protection in the ultra-low temperature range can be separated from the low-pressure protection in the normal temperature range. In the control logic of the air conditioning system, compressor low-pressure protection at ultra-low temperatures is unreliable. Even if compressor low-pressure protection occurs, it cannot accurately indicate that the whole unit is short of refrigerant or that a certain component of the whole unit is abnormally controlled. However, compressor low-pressure protection in the normal temperature range is reliable. Once compressor low-pressure protection occurs, it can accurately indicate that the whole unit is short of refrigerant or that a certain component of the whole unit is abnormally controlled.

[0107] In related solutions, the compressor low-pressure protection can automatically recover within a certain number of times, but will shut down if it exceeds a certain number of times; if the compressor low-pressure protection reaches a certain number of times within a certain time, it will lock up, display a fault, and cannot be reset without manual intervention; within a certain number of times, each protection trigger condition is that the compressor stops for a period of time and then restarts, until a certain number of times are reached and the protection condition is triggered, at which point an alarm signal is issued; etc., which are unreliable for large engineering units, especially under conditions where the indoor and outdoor units are connected by long pipes. The solution of this invention records the compressor low-pressure protection under different outdoor temperatures OUTtemp and performs conditional automatic reset processing for unreliable compressor low-pressure protection. In addition, if the compressor can run normally for a long time after resuming operation after low-pressure protection, all accumulated protection counts are cleared. This can protect the compressor and greatly reduce the risk of the compressor locking up and not being able to automatically reset due to frequent compressor low-pressure protection. It is more practical for large engineering units, such as computer room air conditioners, multi-split systems, etc., especially when there are long connecting pipes between the indoor and outdoor units of the air conditioning system. The so-called long connecting pipe refers to the installation distance between the indoor unit and the outdoor unit of the air conditioning system, which is generally more than 20 meters. Ordinary household air conditioners generally do not involve long connecting pipes.

[0108] The solution of this invention categorizes compressor low-pressure protection under different conditions, allowing for flexible handling of this categorization and minimizing compressor lockup due to frequent low-pressure protection activation. This avoids complex control logic design and eliminates the need for cryogenic components in engineering. Under normal circumstances, compressor low-pressure protection is executed promptly and effectively, while preventing excessive accumulation of low-pressure protection activations that could lead to compressor lockup and inability to automatically resume operation. Therefore, this solution addresses both the problem of compressor low-pressure protection requiring timely and effective execution without unlimited activation to prevent compressor damage, and the problem of limiting the number of low-pressure protection activations causing compressor lockup and requiring manual intervention for reset or power-off and power-back operation to restore normal operation. As can be seen, the solution of this invention is mainly aimed at low-pressure protection in the case of long connecting pipes between indoor and outdoor units and in ultra-low temperature outdoor conditions. It judges the low-pressure protection of the compressor by using the outdoor ambient temperature OUTtemp and the compressor suction pressure value (i.e., the low-pressure pressure value Clowpress) and distinguishes the protection type. When the outdoor ambient temperature changes, it can clear some of the accumulated number of low-pressure protections, unlock the compressor and restore automatic operation. It can maximize the on-site temperature and humidity control and maximize the protection of the compressor from damage. It has better applicability and stronger versatility.

[0109] The technical solution of this embodiment addresses the situation where a long connecting pipe exists between the indoor and outdoor units in an air conditioning system (i.e., a connecting pipe where the installation distance between the indoor and outdoor units is greater than a set distance). When the entire air conditioning system is powered on and the controller has completed initialization, the outdoor ambient temperature and the compressor's low-pressure value are collected, and the outdoor ambient temperature and compressor's low-pressure value before the compressor starts are recorded. It then determines whether the compressor is already running: if so, a preset compressor low-pressure protection operation detection logic is executed; otherwise, a preset compressor low-pressure protection shutdown detection logic is executed. Furthermore, when executing the preset compressor low-pressure protection operation detection logic or executing... During the preset compressor low-pressure protection shutdown detection logic, the number of compressor low-pressure protection occurrences is cumulatively counted according to the outdoor ambient temperature range. Compressor low-pressure protection occurrences within the normal temperature range are counted in the first category, while those within the ultra-low temperature range are counted in the second category. Specifically, when executing the preset compressor low-pressure protection operation detection logic, it is determined whether the compressor's low-pressure value is continuously below the set pressure threshold and the outdoor ambient temperature is above the critical set temperature for a given period. If both conditions are met, the first category's cumulative count is incremented by 1, and the compressor remains shut down and disabled. The compressor starts, then checks if the sum of the first and second type of cumulative counts is less than a preset number of times. If not, the second type of cumulative count is incremented by 1, and the compressor remains off and is prevented from starting. Then, it checks if the sum of the first and second type of cumulative counts is less than a preset number of times. When executing the preset compressor low-pressure protection shutdown detection logic, it checks if the following conditions are met: the compressor continuous shutdown time exceeds the set shutdown time; the compressor's low-pressure value is detected to be less than the set pressure threshold for a continuous period; and the outdoor ambient temperature is greater than the critical temperature setting. If these conditions are met, the compressor low-pressure protection is displayed, the first type of cumulative count is incremented by 1, and... The compressor is kept off and prevented from starting. Then, it is determined whether the sum of the cumulative count values ​​of the first type and the second type is less than a preset number of times. If not, no display is shown and no compressor low-pressure detection is performed. Then, it returns to re-determine whether the following conditions are met: the compressor continuous shutdown time is longer than the set shutdown time, the compressor low-pressure value is detected to be less than the set pressure threshold for a continuous period of time, and the outdoor ambient temperature is greater than the critical temperature setting value. After determining whether the sum of the cumulative count values ​​of the first type and the second type is less than a preset number of times: if the conditions are met, it is determined whether the compressor can resume automatic operation based on the compressor continuous running time and the compressor low-pressure value for a period of time.If the conditions are not met, the system determines whether the compressor low-pressure protection is activated based on the outdoor ambient temperature before the compressor starts following the previous low-pressure protection activation. This ensures that the compressor, after being locked due to low-pressure protection, cannot automatically resume operation. Under normal operating temperature conditions, it can automatically unlock and resume normal operation without manual reset or power interruption restart. Therefore, by categorizing and cumulatively counting the number of compressor low-pressure protection activations based on the outdoor ambient temperature range, and combining the outdoor ambient temperature with the total cumulative count of compressor low-pressure protection activations, the system determines whether the compressor will automatically resume operation after being locked due to low-pressure protection. This ensures timely and effective execution of compressor low-pressure protection, while preventing excessive accumulation of low-pressure protection activations that could lead to compressor lockup and inability to automatically resume operation. This effectively reduces manual intervention and lowers maintenance costs.

[0110] According to an embodiment of the present invention, a control device for an air conditioning system corresponding to a control method for an air conditioning system is also provided. See also Figure 8 The diagram shows a structural schematic of an embodiment of the device of the present invention. A long connecting pipe connects the indoor and outdoor units of the air conditioning system. The control device of the air conditioning system includes: a data acquisition unit 102 and a control unit 104.

[0111] The acquisition unit 102 is configured to, after the air conditioning system is powered on—specifically, when the entire unit of the air conditioning system is powered on and the controller of the air conditioning system has completed initialization—acquire the outdoor ambient temperature (e.g., outdoor ambient temperature OUTtemp) and the suction pressure value of the compressor in the air conditioning system (e.g., low pressure value Clowpress); record the operating parameters of the air conditioning system before the compressor starts; if the compressor shuts down due to low pressure protection, then re-record the operating parameters of the air conditioning system before the compressor starts. The specific functions and processing of this acquisition unit 102 are described in step S110. Specifically, Figure 9 This is a schematic flowchart illustrating an embodiment of a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split system) according to the present invention. Figure 9As shown, the present invention proposes a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split system), comprising: Step 01: After the air conditioning system (such as a computer room air conditioner or other large multi-split system) is powered on, the controller completes initialization and begins to collect outdoor ambient temperature OUTtemp and compressor low-pressure value ClowPress in real time, and collects and records outdoor ambient temperature OUTtemp and low-pressure value Clowpress in real time before the compressor starts; the recorded values ​​of outdoor ambient temperature OUTtemp and low-pressure value Clowpress remain unchanged after the compressor starts, and after the compressor is turned off, outdoor ambient temperature OUTtemp and low-pressure value Clowpress are re-recorded in real time, and then step 02 is executed.

[0112] The control unit 104 is configured to determine whether the compressor has been turned on. The specific functions and processing of the control unit 104 are described in step S120. Specifically, as follows... Figure 9 As shown, the present invention proposes a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes: step 02, determining whether the compressor is running: if the compressor is not running, performing a compressor low-pressure protection shutdown detection, and proceeding to step 03; if the compressor is running, performing a compressor low-pressure protection operation detection, and proceeding to step 04. Figure 9 In the compressor low-pressure protection control process of the air conditioning system (such as computer room air conditioning or other large multi-split system) shown, the compressor low-pressure protection is divided into compressor shutdown detection and compressor operation detection.

[0113] The control unit 104 is further configured to, if it is determined that the compressor is not turned on, execute a preset shutdown detection logic based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system when performing low-pressure protection on the compressor; and during the execution of the preset shutdown detection logic, perform a categorized cumulative count of the number of times the compressor has performed low-pressure protection based on the outdoor ambient temperature range in the currently recorded parameters of the air conditioning system, to obtain a first type of cumulative count value and / or a second type of cumulative count value of the number of times the compressor has performed low-pressure protection. The specific functions and processing of this control unit 104 are further described in step S130. The first type of cumulative count value is such as NUMA, and the second type of cumulative count value is such as NUMB. Specifically, as shown... Figure 9As shown, the present invention proposes a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split systems), which further includes: step 03, performing compressor low-pressure protection shutdown detection. The compressor shutdown detection is to detect whether there is refrigerant leakage after the entire air conditioning system has been shut down and left undisturbed for a long time (e.g., several days or even several months). At the same time, it must not falsely report low-pressure protection. Therefore, the solution is to not detect compressor low-pressure protection when the outdoor ambient temperature OUTtemp < -30℃, because under extremely low temperature conditions, the refrigerant's gaseous or near-liquid state results in very low expansion pressure within the pipeline.

[0114] In some embodiments, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; when the compressor is not turned on, the control unit 104, when performing low-pressure protection on the compressor, executes a preset shutdown detection logic based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system; and during the execution of the preset shutdown detection logic, according to the range of the outdoor ambient temperature in the currently recorded parameters of the air conditioning system, performs a categorized cumulative count of the number of times the compressor has performed low-pressure protection, obtaining a first type of cumulative count value and / or a second type of cumulative count value of the number of times the compressor has performed low-pressure protection, including:

[0115] The control unit 104 is further configured to, when the compressor is not turned on and low-pressure protection is applied to the compressor, determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than a set shutdown time; the currently recorded suction pressure value of the compressor within a continuous first set detection time is less than a first set pressure threshold; and the currently recorded outdoor ambient temperature of the air conditioning system is greater than a set outdoor ambient temperature threshold. The specific functions and processing of this control unit 104 are further described in step S210. The set shutdown time is, for example, 3 minutes; the first set detection time is, for example, Time2; the first set pressure threshold is, for example, 150 kPa; and the set outdoor ambient temperature threshold is, for example, -30°C.

[0116] The control unit 104 is further configured to, if the conditions are met, display the low-pressure protection status of the compressor, increment the first type of cumulative count of the compressor's low-pressure protection occurrences by 1, keep the compressor off and prevent it from starting, and then, after executing preset shutdown detection logic and / or preset operation detection logic, and after obtaining the first type of cumulative count of the compressor's low-pressure protection occurrences and / or the second type of cumulative count of the compressor's low-pressure protection occurrences, if the compressor stops due to low-pressure protection, then, after the compressor stops due to low-pressure protection, based on the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first and second type of cumulative counts of the compressor's low-pressure protection occurrences, automatically unlock the compressor's low-pressure protection shutdown status to allow the compressor to resume operation. The specific functions and processing of this control unit 104 are also described in step S220.

[0117] The control unit 104 is further configured to, if the conditions are not met, stop executing the preset shutdown detection logic and then return to re-record the operating parameters of the air conditioning system before the compressor starts. That is, if the conditions are not met, the low-pressure protection status of the compressor will not be displayed, nor will the preset shutdown detection logic be executed based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system when the compressor is not running, and then returned to re-record the operating parameters of the air conditioning system before the compressor starts. The specific functions and processing of this control unit 104 are further described in step S230.

[0118] Specifically, such as Figure 9 As shown, the present invention proposes a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes: in step 03, when performing compressor low-pressure protection shutdown detection, determining whether the compressor continuous shutdown time is more than 3 minutes, and the compressor low-pressure value Clowpress < 150 kPa is detected for a continuous Time2 time, and the outdoor ambient temperature OUTtemp > -30°C:

[0119] If the compressor is continuously shut down for more than 3 minutes, and the low pressure value of the compressor (Clowpress) is detected to be <150 kPa for a continuous Time2 period, and the outdoor ambient temperature (OUTtemp) is >30°C, then the compressor low pressure protection will be displayed, the cumulative number of compressor low pressure protection calls (NUMA) will be incremented by 1, the compressor will remain off, and starting will be prohibited.

[0120] Conversely, if the following conditions are not met: the compressor has been continuously stopped for more than 3 minutes, and the low pressure value detected for Time2 is <150KPa, and the outdoor ambient temperature OUTtemp is >-30℃, then the compressor low pressure protection will not be displayed or detected, and step 05 will be executed again.

[0121] The compressor shutdown detection, under normal circumstances, involves the air conditioning system being installed and commissioned. The system is pre-charged with the required amount of refrigerant according to technical specifications. When the unit is powered on, the controller can monitor various parameters in real time, such as evaporator inlet and outlet pipe temperatures, exhaust temperature, outdoor ambient temperature, suction pressure, and condensing pressure. With the compressor off, the system uses the detected suction pressure to determine if there is a refrigerant leak. For example, under normal refrigerant charge conditions, the compressor suction pressure is approximately between 1000 kPa and 1500 kPa at room temperature. If the detected suction pressure is very low, such as below 150 kPa, it is determined to be a refrigerant shortage.

[0122] The control unit 104 is further configured to, if it is determined that the compressor is turned on, execute a preset operation detection logic based on the currently recorded operating parameters of the air conditioning system when performing low-pressure protection on the compressor; and during the execution of the preset operation detection logic, perform a categorized cumulative count of the number of times the compressor has performed low-pressure protection based on the outdoor ambient temperature range in the currently recorded parameters of the air conditioning system, to obtain a first-type cumulative count value and / or a second-type cumulative count value of the number of times the compressor has performed low-pressure protection. The specific functions and processing of this control unit 104 are further described in step S140. Specifically, as follows... Figure 9 As shown, the present invention proposes a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split systems), which further includes: Step 04, performing compressor low-pressure protection operation detection. Compressor operation detection is to check whether the compressor intake and exhaust meet normal operating conditions (i.e., whether the relevant technical parameters meet the requirements in the compressor technical specifications) during the overall operation of the air conditioning system. During compressor operation, if there is pipe blockage, insufficient refrigerant, load damage or abnormal wiring leading to uncontrolled load, or compressor reversal due to electrical wiring errors, the compressor intake pressure (i.e., low-pressure) may become extremely low, exceeding the normal operating range. If protection is not implemented in time, it can easily damage the compressor.

[0123] In some embodiments, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; when the compressor is turned on, the control unit 104, when performing low-pressure protection on the compressor, executes a preset operation detection logic based on the currently recorded operating parameters of the air conditioning system; and during the execution of the preset operation detection logic, based on the range of the outdoor ambient temperature in the currently recorded parameters of the air conditioning system, performs a categorized cumulative count of the number of times the compressor performs low-pressure protection, obtaining a first type of cumulative count value and / or a second type of cumulative count value of the number of times the compressor performs low-pressure protection, including:

[0124] The control unit 104 is further configured to, when the compressor is turned on and low-pressure protection is applied to the compressor, determine whether the following conditions are met: the currently recorded suction pressure value of the compressor within a continuous second set detection time is less than a first set pressure threshold, and the currently recorded outdoor ambient temperature of the air conditioning system is greater than a critical temperature set value. The specific functions and processing of this control unit 104 are further described in step S310. The second set detection time is, for example, Time1 time; the first set pressure threshold is, for example, 150 kPa; and the critical temperature set value is, for example, Tset.

[0125] The control unit 104 is further configured to, if the condition is met, increment the first type of cumulative count of the number of times the compressor has experienced low-pressure protection by 1, keep the compressor off and prevent it from starting, and then, after executing preset shutdown detection logic and / or preset operation detection logic, and after obtaining the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and / or the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, if the compressor stops due to low-pressure protection, then, after the compressor stops due to low-pressure protection, based on the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, automatically unlock the compressor to allow it to resume operation. The specific functions and processing of this control unit 104 are also described in step S320.

[0126] The control unit 104 is further configured to, if the condition is not met, increment the second type of cumulative count of the number of times the compressor has experienced low-pressure protection by 1, keep the compressor off and prevent it from starting. Then, after executing preset shutdown detection logic and / or preset operation detection logic, and after obtaining the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and / or the second type of cumulative count, if the compressor stops due to low-pressure protection, then, after the compressor stops due to low-pressure protection, based on the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first and second type of cumulative counts of the number of times the compressor has experienced low-pressure protection, automatically unlock the compressor to allow it to resume operation. The specific functions and processing of this control unit 104 are further described in step S330.

[0127] Specifically, such as Figure 9 As shown, the present invention proposes a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes: in step 04, when performing compressor low-pressure protection operation detection, determining whether the following conditions are met: the compressor low-pressure value Clowpress < 150 kPa is detected continuously for Time1, and the outdoor ambient temperature OUTtemp > the critical set temperature Tset.

[0128] If the compressor is already running and the low pressure value Clowpress < 150 kPa is detected for a continuous Time1 period, when the outdoor ambient temperature OUTtemp > the critical set temperature Tset, the compressor low pressure protection cumulative count NUMA is incremented by 1, the compressor remains off and is prohibited from starting, and then step 05 is executed.

[0129] Conversely, when the outdoor ambient temperature OUTtemp ≤ the critical temperature setpoint Tset, the cumulative number of low-pressure protection cycles for the compressor NUMB is incremented by 1, the compressor remains off and is prohibited from being turned on, and then step 05 is executed.

[0130] The compressor operation detection involves continuously detecting a suction pressure of less than 150 kPa within a certain period after the compressor is started, which indicates low-pressure protection. Common causes of low-pressure protection include refrigerant shortage, obstructed piping leading to abnormal refrigerant circulation, or excessively long piping preventing the establishment of effective refrigerant circulation within a short time.

[0131] The control unit 104 is further configured to, after executing preset shutdown detection logic and / or executing preset operation detection logic, and after obtaining the first type of cumulative count value and / or the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, if the compressor stops due to low-pressure protection, then, after the compressor stops due to low-pressure protection, based on the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, control the compressor to automatically unlock the low-pressure protection shutdown situation so that the compressor can resume operation. The specific functions and processing of this control unit 104 are also described in step S150. The current continuous shutdown time of the compressor is the shutdown time since the compressor last stopped after the air conditioning system was powered on. Specifically, as shown in step S150... Figure 9 As shown, the present invention proposes a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split systems), which further includes: classifying compressor low-pressure protection under different conditions, specifically classifying the cumulative number of compressor low-pressure protections according to the range of outdoor ambient temperature OUTtemp into cumulative number A (i.e., NUMA) and cumulative number B (i.e., NUMB). NUMA represents the cumulative number of protections within a stable temperature range, which is generally unlikely to occur under normal circumstances; its occurrence indicates a genuine abnormality in the unit's operation. NUMB represents the cumulative number of protections within an unstable temperature range, which is generally affected by the connecting pipe between the indoor and outdoor units and the compressor's performance, and is more likely to occur under extremely low temperatures, but its occurrence does not necessarily indicate a abnormality in the unit's operation; the device can automatically reset to zero when the compressor's outdoor ambient temperature OUTtemp rises above the critical set temperature Tset. Related solutions do not distinguish between the types of cumulative low-pressure protection counts for compressors. However, the solution of this invention requires differentiation. For example, based on the range of the outdoor ambient temperature OUTtemp of the compressor, the cumulative low-pressure protection counts can be divided into cumulative counts A (i.e., NUMA) and cumulative counts B (i.e., NUMB). In this way, by classifying the compressor low-pressure protection under different conditions, the compressor low-pressure protection can be flexibly handled after classification, so as to avoid the compressor from locking up due to frequent low-pressure protection. This avoids complex control logic design and eliminates the need for low-temperature components in engineering.

[0132] This invention proposes a compressor low-pressure protection control device for an air conditioning system. It distinguishes the type of accumulated low-pressure protection count based on the outdoor ambient temperature range of the air conditioning system. When the accumulated low-pressure protection count reaches 12 or more, the compressor remains shut down and is not allowed to start. The system determines whether to display compressor low-pressure protection based on the outdoor ambient temperature before the last compressor start. When the outdoor ambient temperature rises above the critical set temperature, the accumulated low-pressure protection count for the ultra-low temperature range is automatically cleared, allowing the compressor to unlock and automatically resume operation. This categorizes compressor low-pressure protection under different conditions, enabling flexible handling and minimizing the risk of compressor lockup due to frequent low-pressure protection. This avoids complex control logic design and eliminates the need for low-temperature components in engineering.

[0133] In some embodiments, the currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; after executing preset shutdown detection logic and / or executing preset operation detection logic, and after obtaining the first type of cumulative count value of the number of times the compressor has experienced low-pressure protection and / or the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, if the compressor stops due to low-pressure protection, then after the compressor stops due to low-pressure protection, combining the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, the control unit 104 controls the compressor to automatically unlock the low-pressure protection shutdown situation so that the compressor can resume operation, including:

[0134] The control unit 104 is further configured to determine the sum of a first type of cumulative count of the number of times the compressor has experienced low-pressure protection and a second type of cumulative count of the number of times the compressor has experienced low-pressure protection, denoted as the total cumulative count of the number of times the compressor has experienced low-pressure protection; and to determine whether the total cumulative count of the number of times the compressor has experienced low-pressure protection is greater than or equal to a preset shutdown protection count threshold. The specific functions and processing of this control unit 104 are further described in step S410. The preset shutdown protection count threshold is, for example, 12 times.

[0135] The control unit 104 is further configured to, if the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is greater than or equal to a preset shutdown protection threshold, determine whether to display the low-pressure protection status of the compressor based on the currently recorded outdoor ambient temperature of the air conditioning system and the first and second type of cumulative counts of the number of times the compressor has experienced low-pressure protection, and control the compressor to automatically unlock the shutdown due to low-pressure protection, so that the compressor can resume operation; wherein, the currently recorded outdoor ambient temperature of the air conditioning system is the outdoor ambient temperature of the air conditioning system recorded after the total cumulative count of the number of times the compressor has experienced low-pressure protection minus one shutdown due to low-pressure protection, and before the compressor is restarted. The specific functions and processing of this control unit 104 are also described in step S420.

[0136] The control unit 104 is further configured to, if the condition is not met, automatically unlock the compressor from low-pressure protection shutdown if the sum of the first type of cumulative count value and the second type of cumulative count value of the compressor's low-pressure protection occurrences is less than a preset shutdown protection count threshold, based on the compressor's current continuous shutdown time, the currently recorded compressor suction pressure value, the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second type of cumulative count values ​​of the compressor's low-pressure protection occurrences, so as to allow the compressor to resume operation. The specific functions and processing of this control unit 104 are further described in step S430.

[0137] Specifically, such as Figure 9 As shown, the present invention provides a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes:

[0138] Step 05: After the compressor stops due to low pressure protection, determine whether the sum of the cumulative number of low pressure protection calls NUMA and NUMB is ≥12. If not, determine whether the compressor can resume automatic operation and proceed to step 06. If it is satisfied, determine whether the compressor low pressure protection is displayed and proceed to step 07.

[0139] Referring to the example shown in step 05, the principle for distinguishing the cumulative number of compressor low-pressure protection events is as follows: The cumulative number of low-pressure protection events is divided into cumulative number A (NUMA) and cumulative number B (NUMB) based on the range of the outdoor ambient temperature OUTtemp of the compressor. Record the outdoor ambient temperature OUTtemp before the compressor starts running. If low-pressure protection occurs after the compressor starts running, determine whether the low-pressure protection is classified as cumulative number A or cumulative number B based on the recorded outdoor ambient temperature OUTtemp. For example, if the outdoor ambient temperature before the compressor starts is below -25℃, low-pressure protection after the compressor starts is recorded as cumulative number B; conversely, if the outdoor ambient temperature is above -25℃, low-pressure protection is recorded as cumulative number A.

[0140] The critical temperature value Tset can be set according to actual needs. Specifically, the critical low temperature start-up temperature value can be reasonably set according to the length of the connecting pipe between the indoor and outdoor units and the climate characteristics of the location of use. This can maximize the safe start-up of the compressors of different units and maximize the accuracy of timely on-site temperature and humidity control.

[0141] Step 06: If the sum of the cumulative number of low-pressure protection calls (NUMA and NUMB) is less than 12, determine whether the compressor should automatically resume operation.

[0142] Step 07: If the cumulative number of compressor low-pressure protection calls is ≥12, determine whether to display compressor low-pressure protection.

[0143] In some embodiments, the control unit 104, when the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is greater than or equal to a preset shutdown protection threshold, determines whether to display the low-pressure protection status of the compressor based on the currently recorded outdoor ambient temperature of the air conditioning system and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, and controls the compressor to automatically unlock the shutdown status due to low-pressure protection, so that the compressor can resume operation, including:

[0144] The control unit 104 is further configured to determine whether the currently recorded outdoor ambient temperature critical temperature setting of the air conditioning system is met when the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is greater than or equal to a preset shutdown protection number threshold. If the condition is met, the system displays the low-pressure protection status of the compressor, keeps the compressor off, and prohibits the compressor from starting. If the condition is not met, the system does not display the low-pressure protection status of the compressor, keeps the compressor off, and prohibits the compressor from starting. The specific functions and processing of the control unit 104 are further described in step S510. The currently recorded outdoor ambient temperature of the air conditioning system is the outdoor ambient temperature recorded after the total cumulative count of the number of times the compressor has experienced low-pressure protection minus one instance of the compressor shutting down due to low-pressure protection, and before the compressor restarts.

[0145] The control unit 104 is further configured to determine whether the outdoor ambient temperature of the air conditioning system currently recorded within a third consecutive set detection time is greater than a critical temperature set value. If so, the second type of cumulative count value of the number of times the compressor experiences low-pressure protection is cleared, and then it is determined whether the sum of the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor experiences low-pressure protection is less than a preset shutdown protection number threshold. If not, it is determined whether the sum of the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor experiences low-pressure protection is less than a preset shutdown protection number threshold. The specific functions and processing of this control unit 104 are further described in step S520. The third set detection time is, for example, Time4.

[0146] The control unit 104 is further configured to, if the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than a preset shutdown protection threshold, then clear the display of the low-pressure protection status of the compressor. That is, if the low-pressure protection status of the compressor has already been displayed, clear the display; if the low-pressure protection status of the compressor has not been displayed, continue not to display it. Then, if the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than the preset shutdown protection threshold, based on the current continuous shutdown time of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, automatically unlock the compressor to allow it to resume operation. The specific functions and processing of this control unit 104 are also described in step S530.

[0147] The control unit 104 is further configured to, if the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is greater than or equal to a preset shutdown protection count threshold, return to display the low-pressure protection status of the compressor, keep the compressor off, and prevent the compressor from starting. The specific functions and processing of this control unit 104 are further described in step S540.

[0148] Specifically, such as Figure 9 As shown, the present invention provides a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes:

[0149] In step 07, if the cumulative number of compressor low-pressure protections is ≥12, then check whether the outdoor ambient temperature OUTtemp before the compressor starts after the 11th compressor low-pressure protection is greater than the critical temperature setting value Tset: if it is satisfied, then the compressor low-pressure protection is displayed, the compressor remains off, and starting is prohibited; if it is not satisfied, then the compressor low-pressure protection is not displayed, the compressor remains off, and starting is prohibited, and then proceed to step 08.

[0150] Step 08: When the outdoor ambient temperature OUTtemp is detected to be greater than the critical temperature setpoint Tset for a continuous Time4 period, the cumulative count NUMB is cleared. If the sum of the compressor low-pressure protection counts NUMA and NUMB is less than 12 times, the compressor low-pressure protection display is cleared, and then the process is repeated as in step 06.

[0151] In some embodiments, the control unit 104, when the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than a preset shutdown protection threshold, controls the compressor to automatically unlock the low-pressure protection shutdown situation based on the current continuous shutdown time of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, so as to allow the compressor to resume operation, including:

[0152] The control unit 104 is further configured to determine whether the following conditions are met when the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than a preset shutdown protection count threshold: the current continuous shutdown time of the compressor is greater than a set shutdown time, and the currently recorded suction pressure value of the compressor within a fourth consecutive set detection time is greater than a second set pressure. The specific function and processing of this control unit 104 are further described in step S610. The second set pressure is, for example, 250 kPa, and the fourth set detection time is, for example, Time3.

[0153] The control unit 104 is further configured to automatically unlock the compressor in the event of a low-pressure protection shutdown if the condition is met, thereby allowing the compressor to resume operation. Then, based on the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running, the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection are adjusted. The specific functions and processing of this control unit 104 are further described in step S620.

[0154] The control unit 104 is further configured to, if the condition is not met, return to the previous state and continue executing the preset shutdown detection logic and / or the preset operation detection logic. After obtaining the first type of cumulative count value and / or the second type of cumulative count value of the compressor's low-pressure protection occurrences, if the compressor shuts down due to low-pressure protection, then, after the compressor shuts down due to low-pressure protection, based on the compressor's current continuous shutdown time, the currently recorded operating parameters of the air conditioning system, and the first and second type of cumulative count values ​​of the compressor's low-pressure protection occurrences, the control unit 104 is configured to automatically unlock the compressor's low-pressure protection shutdown status, thereby allowing the compressor to resume operation. The specific functions and processing of this control unit 104 are further described in step S630.

[0155] Specifically, such as Figure 9 As shown, the present invention proposes a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes: in step 06, if the sum of the cumulative number of compressor low-pressure protection NUMA and NUMB is less than 12 times, and the compressor has been continuously stopped for more than 3 minutes, and the low-pressure value detected for a continuous Time3 time is greater than 250KPa, the compressor automatically resumes operation, and then the process proceeds to step 09.

[0156] In some embodiments, the control unit 104 automatically unlocks when the compressor stops due to low-pressure protection, allowing the compressor to resume operation. Then, based on the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started operating, it adjusts the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, including:

[0157] The control unit 104 is further configured to determine whether the outdoor ambient temperature of the air conditioning system currently recorded within a fifth consecutive set detection time is greater than a critical temperature set value. If so, the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection is cleared, and then it is determined whether the compressor has been started within a sixth consecutive detection time. If not, it is determined whether the compressor has been started within a sixth consecutive detection time. The specific functions and processing of this control unit 104 are further described in step S710.

[0158] The control unit 104 is further configured to, if it is determined whether the compressor has been started within the sixth consecutive detection time, clear the first type of cumulative count value of the number of times the compressor has experienced low-pressure protection, and clear the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, and then return to re-record the operating parameters of the air conditioning system before the compressor was started. The specific functions and processing of this control unit 104 are further described in step S720.

[0159] The control unit 104 is further configured to return to the previous state if it is determined that the compressor has not been started within the sixth consecutive detection period, so as to re-record the operating parameters of the air conditioning system before the compressor was started. The specific functions and processing of this control unit 104 are further described in step S730.

[0160] Specifically, such as Figure 9 As shown, the present invention provides a compressor low-pressure protection control device for an air conditioning system (such as a computer room air conditioner or other large multi-split system), which further includes:

[0161] Step 09: If the outdoor ambient temperature OUTtemp is detected to be greater than the critical temperature setting Tset for a continuous Time 5 period, clear the accumulated count NUMB and then proceed to step 10. If the count is less than "If the outdoor ambient temperature OUTtemp is detected to be greater than the critical temperature setting Tset for a continuous Time 5 period, then proceed directly to step 10".

[0162] Step 10: If the compressor is running and continuous operation is detected for a continuous Time6 period, clear the accumulated counts NUMA and NUMB, then return to step 01 and repeat the process. Referring to the examples shown in steps 06 to 10, in this invention, the type of accumulated count for compressor low-pressure protection is distinguished based on the outdoor ambient temperature OUTtemp range. This is divided into accumulated counts NUMA for the normal temperature range and accumulated counts NUMB for the ultra-low temperature range. When the sum of these two counts reaches 12 or more, the compressor remains off and is prohibited from starting. When the outdoor ambient temperature OUTtemp rises above the critical set temperature Tset, the accumulated counts NUMB for compressor low-pressure protection in the ultra-low temperature range are automatically cleared, making the sum of the accumulated counts less than 12, thereby unlocking the compressor and automatically resuming operation. In this way, the compressor cannot automatically resume operation after being locked due to low pressure protection. Under normal operating temperature conditions, it can automatically unlock and resume normal operation without manual reset or power failure restart. Thus, it can effectively and timely implement compressor low pressure protection, and also avoid the compressor being locked due to excessive accumulation of low pressure protection, which can effectively reduce manual intervention and lower operation and maintenance costs.

[0163] Referring to the examples shown in steps 01 to 10, in the solution of this invention, after the compressor experiences low-pressure protection, the cumulative number of compressor low-pressure protection calls (NUMA and NUMB) is calculated according to the range of the compressor's outdoor ambient temperature (OUTtemp). When the sum of the cumulative numbers of NUMA and NUMB is greater than or equal to 12, the outdoor ambient temperature (OUTtemp) before the 12th low-pressure protection call is used to determine whether to display compressor low-pressure protection and whether to lock the compressor so that it cannot automatically resume operation. When the outdoor ambient temperature (OUTtemp) rises to a critical temperature value (Tset) or higher, the cumulative number of calls (NUMB) is reset to zero, making the sum of the cumulative numbers less than 12, thus removing the restriction that the compressor cannot automatically resume operation due to low-pressure protection. Alternatively, after the compressor experiences low-pressure protection, the cumulative number of compressor low-pressure protection calls (NUMA and NUMB) is calculated according to the range of the compressor's outdoor ambient temperature (OUTtemp). If the sum of the cumulative numbers of NUMA and NUMB is less than 12, and the compressor can run normally for more than 5 minutes, then the cumulative number of compressor low-pressure protection calls (NUMA and NUMB) is reset to zero, and the compressor low-pressure protection call count is re-detected and accumulated.

[0164] In particular, due to the influence of ultra-low temperature environments, the refrigerant has poor fluidity based on the principle of thermal expansion and contraction. If combined with actual engineering conditions, such as long pipe connections between indoor and outdoor units, it is difficult to establish effective refrigerant circulation after the compressor is turned on. In this case, compressor low-pressure protection is prone to occur. By distinguishing and recording the cumulative number of compressor low-pressure protections based on the range of outdoor ambient temperature OUTtemp, the low-pressure protection in the ultra-low temperature range can be separated from the low-pressure protection in the normal temperature range. In the control logic of the air conditioning system, compressor low-pressure protection at ultra-low temperatures is unreliable. Even if compressor low-pressure protection occurs, it cannot accurately indicate that the whole unit is short of refrigerant or that a certain component of the whole unit is abnormally controlled. However, compressor low-pressure protection in the normal temperature range is reliable. Once compressor low-pressure protection occurs, it can accurately indicate that the whole unit is short of refrigerant or that a certain component of the whole unit is abnormally controlled.

[0165] In related solutions, the compressor low-pressure protection can automatically recover within a certain number of times, but will shut down if it exceeds a certain number of times; if the compressor low-pressure protection reaches a certain number of times within a certain time, it will lock up, display a fault, and cannot be reset without manual intervention; within a certain number of times, each protection trigger condition is that the compressor stops for a period of time and then restarts, until a certain number of times are reached and the protection condition is triggered, at which point an alarm signal is issued; etc., which are unreliable for large engineering units, especially under conditions where the indoor and outdoor units are connected by long pipes. The solution of this invention records the compressor low-pressure protection under different outdoor temperatures OUTtemp and performs conditional automatic reset processing for unreliable compressor low-pressure protection. In addition, if the compressor can run normally for a long time after resuming operation after low-pressure protection, all accumulated protection counts are cleared. This can protect the compressor and greatly reduce the risk of the compressor locking up and not being able to automatically reset due to frequent compressor low-pressure protection. It is more practical for large engineering units, such as computer room air conditioners, multi-split systems, etc., especially when there are long connecting pipes between the indoor and outdoor units of the air conditioning system. The so-called long connecting pipe refers to the installation distance between the indoor unit and the outdoor unit of the air conditioning system, which is generally more than 20 meters. Ordinary household air conditioners generally do not involve long connecting pipes.

[0166] The solution of this invention categorizes compressor low-pressure protection under different conditions, allowing for flexible handling of this categorization and minimizing compressor lockup due to frequent low-pressure protection activation. This avoids complex control logic design and eliminates the need for cryogenic components in engineering. Under normal circumstances, compressor low-pressure protection is executed promptly and effectively, while preventing excessive accumulation of low-pressure protection activations that could lead to compressor lockup and inability to automatically resume operation. Therefore, this solution addresses both the problem of compressor low-pressure protection requiring timely and effective execution without unlimited activation to prevent compressor damage, and the problem of limiting the number of low-pressure protection activations causing compressor lockup and requiring manual intervention for reset or power-off and power-back operation to restore normal operation. As can be seen, the solution of this invention is mainly aimed at low-pressure protection in the case of long connecting pipes between indoor and outdoor units and in ultra-low temperature outdoor conditions. It judges the low-pressure protection of the compressor by using the outdoor ambient temperature OUTtemp and the compressor suction pressure value (i.e., the low-pressure pressure value Clowpress) and distinguishes the protection type. When the outdoor ambient temperature changes, it can clear some of the accumulated number of low-pressure protections, unlock the compressor and restore automatic operation. It can maximize the on-site temperature and humidity control and maximize the protection of the compressor from damage. It has better applicability and stronger versatility.

[0167] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0168] Using the technical solution of this invention, in cases where there is a long connecting pipe between the indoor and outdoor units in an air conditioning system (i.e., a connecting pipe where the installation distance between the indoor and outdoor units is greater than a set distance), when the entire air conditioning system is powered on and the controller of the air conditioning system has completed initialization, the outdoor ambient temperature and the low-pressure value of the compressor are collected, and the outdoor ambient temperature and the low-pressure value of the compressor before the compressor starts are recorded; it is determined whether the compressor has started running: if so, a preset compressor low-pressure protection operation detection logic is executed; otherwise, a preset compressor low-pressure protection shutdown detection logic is executed; and, when the preset compressor low-pressure protection operation detection logic is executed or the preset compressor low-pressure protection shutdown detection logic is executed... In the compressor low-pressure protection shutdown detection logic, the number of compressor low-pressure protection occurrences is cumulatively counted according to the outdoor ambient temperature range. Compressor low-pressure protection occurrences within the normal temperature range are counted in the first category, while those within the ultra-low temperature range are counted in the second category. Specifically, when executing the preset compressor low-pressure protection operation detection logic, it is determined whether the compressor's low-pressure value is continuously below a set pressure threshold and the outdoor ambient temperature is above a critical set temperature for a given period. If both conditions are met, the first category's cumulative count is incremented by 1, and the compressor remains shut down and is disabled. The compressor starts, then checks if the sum of the first and second type of cumulative counts is less than a preset number of times. If not, the second type of cumulative count is incremented by 1, and the compressor remains off and is prevented from starting. Then, it checks if the sum of the first and second type of cumulative counts is less than a preset number of times. When executing the preset compressor low-pressure protection shutdown detection logic, it checks if the following conditions are met: the compressor continuous shutdown time exceeds the set shutdown time; the compressor's low-pressure value is detected to be less than the set pressure threshold for a continuous period; and the outdoor ambient temperature is greater than the critical temperature setting. If these conditions are met, the compressor low-pressure protection is displayed, the first type of cumulative count is incremented by 1, and... The compressor is kept off and prevented from starting. Then, it is determined whether the sum of the cumulative count values ​​of the first type and the second type is less than a preset number of times. If not, no display is shown and no compressor low-pressure detection is performed. Then, it returns to re-determine whether the following conditions are met: the compressor continuous shutdown time is longer than the set shutdown time, the compressor low-pressure value is detected to be less than the set pressure threshold for a continuous period of time, and the outdoor ambient temperature is greater than the critical temperature setting value. After determining whether the sum of the cumulative count values ​​of the first type and the second type is less than a preset number of times: if the conditions are met, it is determined whether the compressor can resume automatic operation based on the compressor continuous running time and the compressor low-pressure value for a period of time.If these conditions are not met, the system determines whether the compressor's low-pressure protection is activated based on the outdoor ambient temperature before the compressor starts following the previous low-pressure protection activation. This prevents the compressor from automatically resuming operation after being locked due to low-pressure protection. Under normal operating temperature conditions, the compressor automatically unlocks and resumes normal operation without manual reset or power interruption restart. When the outdoor ambient temperature changes, some of the accumulated low-pressure protection activations can be cleared, unlocking the compressor and restoring automatic operation. This maximizes on-site temperature and humidity control while also protecting the compressor from damage, resulting in higher reliability.

[0169] According to an embodiment of the present invention, an air conditioning system corresponding to a control device for an air conditioning system is also provided. This air conditioning system may include the control device for the air conditioning system described above.

[0170] Since the processing and functions implemented by the air conditioning system in this embodiment are basically the same as those of the aforementioned device embodiments, principles and examples, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0171] Using the technical solution of this invention, in cases where there is a long connecting pipe between the indoor and outdoor units in an air conditioning system (i.e., a connecting pipe where the installation distance between the indoor and outdoor units is greater than a set distance), when the entire air conditioning system is powered on and the controller of the air conditioning system has completed initialization, the outdoor ambient temperature and the low-pressure value of the compressor are collected, and the outdoor ambient temperature and the low-pressure value of the compressor before the compressor starts are recorded; it is determined whether the compressor has started running: if so, a preset compressor low-pressure protection operation detection logic is executed; otherwise, a preset compressor low-pressure protection shutdown detection logic is executed; and, when the preset compressor low-pressure protection operation detection logic is executed or the preset compressor low-pressure protection shutdown detection logic is executed... In the compressor low-pressure protection shutdown detection logic, the number of compressor low-pressure protection occurrences is cumulatively counted according to the outdoor ambient temperature range. Compressor low-pressure protection occurrences within the normal temperature range are counted in the first category, while those within the ultra-low temperature range are counted in the second category. Specifically, when executing the preset compressor low-pressure protection operation detection logic, it is determined whether the compressor's low-pressure value is continuously below a set pressure threshold and the outdoor ambient temperature is above a critical set temperature for a given period. If both conditions are met, the first category's cumulative count is incremented by 1, and the compressor remains shut down and is disabled. The compressor starts, then checks if the sum of the first and second type of cumulative counts is less than a preset number of times. If not, the second type of cumulative count is incremented by 1, and the compressor remains off and is prevented from starting. Then, it checks if the sum of the first and second type of cumulative counts is less than a preset number of times. When executing the preset compressor low-pressure protection shutdown detection logic, it checks if the following conditions are met: the compressor continuous shutdown time exceeds the set shutdown time; the compressor's low-pressure value is detected to be less than the set pressure threshold for a continuous period; and the outdoor ambient temperature is greater than the critical temperature setting. If these conditions are met, the compressor low-pressure protection is displayed, the first type of cumulative count is incremented by 1, and... The compressor is kept off and prevented from starting. Then, it is determined whether the sum of the cumulative count values ​​of the first type and the second type is less than a preset number of times. If not, no display is shown and no compressor low-pressure detection is performed. Then, it returns to re-determine whether the following conditions are met: the compressor continuous shutdown time is longer than the set shutdown time, the compressor low-pressure value is detected to be less than the set pressure threshold for a continuous period of time, and the outdoor ambient temperature is greater than the critical temperature setting value. After determining whether the sum of the cumulative count values ​​of the first type and the second type is less than a preset number of times: if the conditions are met, it is determined whether the compressor can resume automatic operation based on the compressor continuous running time and the compressor low-pressure value for a period of time.If the conditions are not met, the system determines whether the compressor low-pressure protection is activated based on the outdoor ambient temperature before the compressor starts following the previous low-pressure protection activation. This ensures that the compressor, locked due to low-pressure protection, cannot automatically resume operation. Under normal operating temperature conditions, the system automatically unlocks and resumes normal operation without manual reset or power interruption. Under normal circumstances, this effectively and promptly implements compressor low-pressure protection, preventing excessive accumulation of low-pressure protection activations that could lead to compressor lockup and inability to automatically resume operation.

[0172] According to an embodiment of the present invention, a storage medium corresponding to a control method for an air conditioning system is also provided. The storage medium includes a stored program, wherein the program controls the device where the storage medium is located to execute the control method for the air conditioning system described above when it is executed.

[0173] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0174] Using the technical solution of this invention, in cases where there is a long connecting pipe between the indoor and outdoor units in an air conditioning system (i.e., a connecting pipe where the installation distance between the indoor and outdoor units is greater than a set distance), when the entire air conditioning system is powered on and the controller of the air conditioning system has completed initialization, the outdoor ambient temperature and the low-pressure value of the compressor are collected, and the outdoor ambient temperature and the low-pressure value of the compressor before the compressor starts are recorded; it is determined whether the compressor has started running: if so, a preset compressor low-pressure protection operation detection logic is executed; otherwise, a preset compressor low-pressure protection shutdown detection logic is executed; and, when the preset compressor low-pressure protection operation detection logic is executed or the preset compressor low-pressure protection shutdown detection logic is executed... In the compressor low-pressure protection shutdown detection logic, the number of compressor low-pressure protection occurrences is cumulatively counted according to the outdoor ambient temperature range. Compressor low-pressure protection occurrences within the normal temperature range are counted in the first category, while those within the ultra-low temperature range are counted in the second category. Specifically, when executing the preset compressor low-pressure protection operation detection logic, it is determined whether the compressor's low-pressure value is continuously below a set pressure threshold and the outdoor ambient temperature is above a critical set temperature for a given period. If both conditions are met, the first category's cumulative count is incremented by 1, and the compressor remains shut down and is disabled. The compressor starts, then checks if the sum of the first and second type of cumulative counts is less than a preset number of times. If not, the second type of cumulative count is incremented by 1, and the compressor remains off and is prevented from starting. Then, it checks if the sum of the first and second type of cumulative counts is less than a preset number of times. When executing the preset compressor low-pressure protection shutdown detection logic, it checks if the following conditions are met: the compressor continuous shutdown time exceeds the set shutdown time; the compressor's low-pressure value is detected to be less than the set pressure threshold for a continuous period; and the outdoor ambient temperature is greater than the critical temperature setting. If these conditions are met, the compressor low-pressure protection is displayed, the first type of cumulative count is incremented by 1, and... The compressor is kept off and prevented from starting. Then, it is determined whether the sum of the cumulative count values ​​of the first type and the second type is less than a preset number of times. If not, no display is shown and no compressor low-pressure detection is performed. Then, it returns to re-determine whether the following conditions are met: the compressor continuous shutdown time is longer than the set shutdown time, the compressor low-pressure value is detected to be less than the set pressure threshold for a continuous period of time, and the outdoor ambient temperature is greater than the critical temperature setting value. After determining whether the sum of the cumulative count values ​​of the first type and the second type is less than a preset number of times: if the conditions are met, it is determined whether the compressor can resume automatic operation based on the compressor continuous running time and the compressor low-pressure value for a period of time.If the conditions are not met, the outdoor ambient temperature before the compressor starts after the previous low-pressure protection event determines whether the compressor low-pressure protection is activated. This prevents the compressor from automatically resuming operation after being locked due to low-pressure protection. Under normal operating temperature conditions, the compressor can automatically unlock and resume normal operation without manual reset or power failure. Low-pressure protection events under different conditions are categorized for flexible handling, minimizing the risk of frequent compressor lock-up due to low-pressure protection. This avoids complex control logic design and eliminates the need for cryogenic components in the engineering.

[0175] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0176] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method for an air conditioning system, characterized in that, include: After the air conditioning system is powered on, the operating parameters of the air conditioning system are collected; the operating parameters of the air conditioning system before the compressor is turned on are recorded. If the compressor shuts down due to low pressure protection, the operating parameters of the air conditioning system before the compressor was turned on are recorded again. The currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; Determine whether the compressor is turned on; If it is determined that the compressor is not turned on, when performing low-pressure protection on the compressor, a preset shutdown detection logic is executed based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system. During the execution of the preset shutdown detection logic, it is determined whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, the suction pressure value of the compressor currently recorded within the first set detection time is less than the first set pressure threshold, and the outdoor ambient temperature of the air conditioning system currently recorded is greater than the set outdoor ambient temperature threshold. If these conditions are met, the low-pressure protection status of the compressor is displayed, the first type of cumulative count value of the number of times the compressor has performed low-pressure protection is incremented by 1, and the compressor is kept off and prevented from being turned on. If it is determined that the compressor is turned on, when performing low-pressure protection on the compressor, a preset operation detection logic is executed based on the currently recorded operating parameters of the air conditioning system. During the execution of the preset operation detection logic, it is determined whether the following conditions are met: the currently recorded suction pressure value of the compressor is less than the first preset pressure threshold within a second consecutive set detection time, and the currently recorded outdoor ambient temperature of the air conditioning system is greater than the critical temperature set value. If these conditions are met, the first type of cumulative count value of the number of times the compressor has performed low-pressure protection is incremented by 1, and the compressor is kept off and prevented from turning on. If these conditions are not met, the second type of cumulative count value of the number of times the compressor has performed low-pressure protection is incremented by 1, and the compressor is kept off and prevented from turning on. After the compressor stops due to low pressure protection, the system combines the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has stopped due to low pressure protection to automatically unlock the compressor and allow it to resume operation.

2. The control method for the air conditioning system according to claim 1, characterized in that, When performing low-pressure protection on the compressor, a preset shutdown detection logic is executed based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system. And during the execution of the preset shutdown detection logic, it also includes: Determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, the suction pressure value of the compressor currently recorded within the first set detection time is less than the first set pressure threshold, and the outdoor ambient temperature of the air conditioning system currently recorded is greater than the set outdoor ambient temperature threshold. If the conditions are not met, the preset shutdown detection logic will be stopped.

3. The control method for the air conditioning system according to claim 1 or 2, characterized in that, After the compressor stops due to low-pressure protection, based on the compressor's current continuous shutdown time, the currently recorded operating parameters of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, the compressor is automatically unlocked to resume operation, including: The sum of the first type of cumulative count of the number of times the compressor has low-pressure protection occurred and the second type of cumulative count of the number of times the compressor has low-pressure protection occurred is recorded as the total cumulative count of the number of times the compressor has low-pressure protection occurred; it is then determined whether the following condition is met: the total cumulative count of the number of times the compressor has low-pressure protection occurred is greater than or equal to a preset shutdown protection number threshold. If the conditions are met, then based on the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the compressor low-pressure protection occurrences, it is determined whether to display the low-pressure protection status of the compressor, and to automatically unlock the compressor from the low-pressure protection shutdown state so that the compressor can resume operation; wherein, the currently recorded outdoor ambient temperature of the air conditioning system is the outdoor ambient temperature of the air conditioning system recorded after the cumulative count value of the compressor low-pressure protection occurrences minus 1 low-pressure protection shutdown occurrence, and before the compressor restarts; If the conditions are not met, the compressor will be automatically unlocked due to low-pressure protection based on the compressor's current continuous downtime, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, the first type of cumulative count of the number of times the compressor has experienced low-pressure protection, and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, so that the compressor can resume operation.

4. The control method for the air conditioning system according to claim 3, characterized in that, Based on the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, it is determined whether to display the low-pressure protection status of the compressor, and the compressor is automatically unlocked when it stops due to low-pressure protection, so that the compressor can resume operation. This includes: Determine whether the currently recorded outdoor ambient temperature critical temperature setting value of the air conditioning system is met: if it is met, display the low-pressure protection status of the compressor, keep the compressor off and prevent it from starting; if it is not met, do not display the low-pressure protection status of the compressor, keep the compressor off and prevent it from starting. Determine whether the outdoor ambient temperature of the air conditioning system currently recorded within the third consecutive set detection time is greater than the critical temperature set value: if it is satisfied, then clear the second type of cumulative count value of the number of times the compressor has low-pressure protection, and then determine whether the sum of the first type of cumulative count value of the number of times the compressor has low-pressure protection and the second type of cumulative count value of the number of times the compressor has low-pressure protection is less than the preset shutdown protection number threshold; if it is not satisfied, then determine whether the sum of the first type of cumulative count value of the number of times the compressor has low-pressure protection and the second type of cumulative count value of the number of times the compressor has low-pressure protection is less than the preset shutdown protection number threshold. If the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than the preset shutdown protection threshold, then the display of the compressor experiencing low-pressure protection is cleared. Afterwards, based on the current continuous shutdown time of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, the compressor is controlled to automatically unlock the shutdown situation caused by low-pressure protection, so that the compressor can resume operation. If the sum of the first type of cumulative count of the number of times the compressor has low-pressure protection and the second type of cumulative count of the number of times the compressor has low-pressure protection is greater than or equal to the preset shutdown protection threshold, then return to display the low-pressure protection status of the compressor, keep the compressor off and prevent the compressor from starting.

5. The control method for an air conditioning system according to claim 3, characterized in that, Based on the current continuous downtime of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, the compressor is automatically unlocked when it stops due to low-pressure protection, so that the compressor can resume operation. This includes: Determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, and the current recorded suction pressure value of the compressor is greater than the second set pressure within the fourth consecutive set detection time. If the conditions are met, the compressor will automatically unlock when it stops due to low pressure protection, so that the compressor can resume operation. Then, based on the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running, the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has low pressure protection will be adjusted. If the conditions are not met, the process returns to normal and continues after the compressor stops due to low pressure protection. This is done by combining the compressor's current continuous shutdown time, the currently recorded operating parameters of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has stopped due to low pressure protection. The system then controls the compressor to automatically unlock from the low pressure protection state so that it can resume operation.

6. The control method for the air conditioning system according to claim 4, characterized in that, Based on the current continuous downtime of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, the compressor is automatically unlocked when it stops due to low-pressure protection, so that the compressor can resume operation. This includes: Determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, and the current recorded suction pressure value of the compressor is greater than the second set pressure within the fourth consecutive set detection time. If the conditions are met, the compressor will automatically unlock when it stops due to low pressure protection, so that the compressor can resume operation. Then, based on the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running, the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has low pressure protection will be adjusted. If the conditions are not met, the process returns to normal and continues after the compressor stops due to low pressure protection. This is done by combining the compressor's current continuous shutdown time, the currently recorded operating parameters of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has stopped due to low pressure protection. The system then controls the compressor to automatically unlock from the low pressure protection state so that it can resume operation.

7. The control method for an air conditioning system according to claim 5 or 6, characterized in that, Based on the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running, the first type of cumulative count value and the second type of cumulative count value of the compressor low-pressure protection occurrences are adjusted, including: Determine whether the outdoor ambient temperature of the air conditioning system currently recorded within the fifth consecutive set detection time is greater than the critical temperature set value: if it is satisfied, then clear the second type of cumulative count value of the number of times the compressor has low pressure protection, and then determine whether the compressor has been turned on and running within the sixth consecutive detection time; if it is not satisfied, then determine whether the compressor has been turned on and running within the sixth consecutive detection time. If it is determined whether the compressor has been turned on and running within the sixth consecutive detection time, then the first type of cumulative count value of the number of times the compressor has low pressure protection is cleared, and the second type of cumulative count value of the number of times the compressor has low pressure protection is cleared, and then the process is returned to re-record the operating parameters of the air conditioning system before the compressor is turned on; If it is determined that the compressor has not been turned on during the sixth consecutive detection period, the process returns to record the operating parameters of the air conditioning system before the compressor was turned on.

8. A control device for an air conditioning system, characterized in that, include: The data acquisition unit is configured to acquire the operating parameters of the air conditioning system after the air conditioning system is powered on; and to record the operating parameters of the air conditioning system before the compressor of the air conditioning system is turned on. If the compressor shuts down due to low pressure protection, the operating parameters of the air conditioning system before the compressor was turned on are recorded again. The currently recorded operating parameters of the air conditioning system include: the currently recorded outdoor ambient temperature of the air conditioning system and the currently recorded suction pressure value of the compressor; The control unit is configured to determine whether the compressor has been turned on; The control unit is further configured to, if it is determined that the compressor is not turned on, execute a preset shutdown detection logic based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system when performing low-pressure protection on the compressor; and during the execution of the preset shutdown detection logic, determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, the suction pressure value of the compressor currently recorded within the first set detection time is less than the first set pressure threshold, and the outdoor ambient temperature of the air conditioning system currently recorded is greater than the set outdoor ambient temperature threshold; if these conditions are met, display the low-pressure protection status of the compressor, increment the first type of cumulative count value of the number of times the compressor has performed low-pressure protection by 1, and keep the compressor off and prevent the compressor from turning on; The control unit is further configured to, if it is determined that the compressor is turned on, determine whether the following conditions are met when performing low-pressure protection on the compressor: the suction pressure value of the compressor currently recorded within a second set detection time is less than a first set pressure threshold, and the outdoor ambient temperature of the air conditioning system currently recorded is greater than a critical temperature set value; if these conditions are met, the first type of cumulative count value of the number of times the compressor has performed low-pressure protection is incremented by 1, and the compressor is kept off and prevented from turning on; if these conditions are not met, the second type of cumulative count value of the number of times the compressor has performed low-pressure protection is incremented by 1, and the compressor is kept off and prevented from turning on. The control unit is further configured to, after the compressor stops due to low pressure protection, combine the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has stopped due to low pressure protection, to automatically unlock the compressor so that the compressor can resume operation.

9. The control device for the air conditioning system according to claim 8, characterized in that, The control unit executes a preset shutdown detection logic based on the current continuous shutdown time of the compressor and the currently recorded operating parameters of the air conditioning system. And during the execution of the preset shutdown detection logic, it also includes: Determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, the suction pressure value of the compressor currently recorded within the first set detection time is less than the first set pressure threshold, and the outdoor ambient temperature of the air conditioning system currently recorded is greater than the set outdoor ambient temperature threshold. If the conditions are not met, the preset shutdown detection logic will be stopped.

10. The control device for an air conditioning system according to claim 8 or 9, characterized in that, The control unit, after the compressor stops due to low-pressure protection, combines the current continuous shutdown time of the compressor, the currently recorded operating parameters of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, to automatically unlock the compressor from shutdown due to low-pressure protection, so that the compressor can resume operation. This includes: The sum of the first type of cumulative count of the number of times the compressor has low-pressure protection occurred and the second type of cumulative count of the number of times the compressor has low-pressure protection occurred is recorded as the total cumulative count of the number of times the compressor has low-pressure protection occurred; it is then determined whether the following condition is met: the total cumulative count of the number of times the compressor has low-pressure protection occurred is greater than or equal to a preset shutdown protection number threshold. If the conditions are met, then based on the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count value and the second type of cumulative count value of the compressor low-pressure protection occurrences, it is determined whether to display the low-pressure protection status of the compressor, and to automatically unlock the compressor from the low-pressure protection shutdown state so that the compressor can resume operation; wherein, the currently recorded outdoor ambient temperature of the air conditioning system is the outdoor ambient temperature of the air conditioning system recorded after the cumulative count value of the compressor low-pressure protection occurrences minus 1 low-pressure protection shutdown occurrence, and before the compressor restarts; If the conditions are not met, the compressor will be automatically unlocked due to low-pressure protection based on the compressor's current continuous downtime, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, the first type of cumulative count of the number of times the compressor has experienced low-pressure protection, and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, so that the compressor can resume operation.

11. The control device for an air conditioning system according to claim 10, characterized in that, The control unit, based on the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, determines whether to display the low-pressure protection status of the compressor, and controls the compressor to automatically unlock when it has stopped due to low-pressure protection, so that the compressor can resume operation. This includes: Determine whether the currently recorded outdoor ambient temperature critical temperature setting value of the air conditioning system is met: if it is met, display the low-pressure protection status of the compressor, keep the compressor off and prevent it from starting; if it is not met, do not display the low-pressure protection status of the compressor, keep the compressor off and prevent it from starting. Determine whether the outdoor ambient temperature of the air conditioning system currently recorded within the third consecutive set detection time is greater than the critical temperature set value: if it is satisfied, then clear the second type of cumulative count value of the number of times the compressor has low-pressure protection, and then determine whether the sum of the first type of cumulative count value of the number of times the compressor has low-pressure protection and the second type of cumulative count value of the number of times the compressor has low-pressure protection is less than the preset shutdown protection number threshold; if it is not satisfied, then determine whether the sum of the first type of cumulative count value of the number of times the compressor has low-pressure protection and the second type of cumulative count value of the number of times the compressor has low-pressure protection is less than the preset shutdown protection number threshold. If the sum of the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection is less than the preset shutdown protection threshold, then the display of the compressor experiencing low-pressure protection is cleared. Afterwards, based on the current continuous shutdown time of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first type of cumulative count of the number of times the compressor has experienced low-pressure protection and the second type of cumulative count of the number of times the compressor has experienced low-pressure protection, the compressor is controlled to automatically unlock the shutdown situation caused by low-pressure protection, so that the compressor can resume operation. If the sum of the first type of cumulative count of the number of times the compressor has low-pressure protection and the second type of cumulative count of the number of times the compressor has low-pressure protection is greater than or equal to the preset shutdown protection threshold, then return to display the low-pressure protection status of the compressor, keep the compressor off and prevent the compressor from starting.

12. The control device for an air conditioning system according to claim 10, characterized in that, The control unit, based on the current continuous downtime of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, controls the compressor to automatically unlock from low-pressure protection shutdown, so as to allow the compressor to resume operation. This includes: Determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, and the current recorded suction pressure value of the compressor is greater than the second set pressure within the fourth consecutive set detection time. If the conditions are met, the compressor will automatically unlock when it stops due to low pressure protection, so that the compressor can resume operation. Then, based on the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running, the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has low pressure protection will be adjusted. If the conditions are not met, the process returns to normal and continues after the compressor stops due to low pressure protection. This is done by combining the compressor's current continuous shutdown time, the currently recorded operating parameters of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has stopped due to low pressure protection. The system then controls the compressor to automatically unlock from the low pressure protection state so that it can resume operation.

13. The control device for the air conditioning system according to claim 11, characterized in that, The control unit, based on the current continuous downtime of the compressor, the currently recorded suction pressure value of the compressor, the currently recorded outdoor ambient temperature of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has experienced low-pressure protection, controls the compressor to automatically unlock from low-pressure protection shutdown, so as to allow the compressor to resume operation. This includes: Determine whether the following conditions are met: the current continuous shutdown time of the compressor is greater than the set shutdown time, and the current recorded suction pressure value of the compressor is greater than the second set pressure within the fourth consecutive set detection time. If the conditions are met, the compressor will automatically unlock when it stops due to low pressure protection, so that the compressor can resume operation. Then, based on the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running, the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has low pressure protection will be adjusted. If the conditions are not met, the process returns to normal and continues after the compressor stops due to low pressure protection. This is done by combining the compressor's current continuous shutdown time, the currently recorded operating parameters of the air conditioning system, and the first and second cumulative counts of the number of times the compressor has stopped due to low pressure protection. The system then controls the compressor to automatically unlock from the low pressure protection state so that it can resume operation.

14. The control device for the air conditioning system according to claim 12 or 13, characterized in that, The control unit, taking into account the currently recorded outdoor ambient temperature of the air conditioning system and whether the compressor has started running, adjusts the first type of cumulative count value and the second type of cumulative count value of the number of times the compressor has experienced low-pressure protection, including: Determine whether the outdoor ambient temperature of the air conditioning system currently recorded within the fifth consecutive set detection time is greater than the critical temperature set value: if it is satisfied, then clear the second type of cumulative count value of the number of times the compressor has low pressure protection, and then determine whether the compressor has been turned on and running within the sixth consecutive detection time; if it is not satisfied, then determine whether the compressor has been turned on and running within the sixth consecutive detection time. If it is determined whether the compressor has been turned on and running within the sixth consecutive detection time, then the first type of cumulative count value of the number of times the compressor has low pressure protection is cleared, and the second type of cumulative count value of the number of times the compressor has low pressure protection is cleared, and then the process is returned to re-record the operating parameters of the air conditioning system before the compressor is turned on; If it is determined that the compressor has not been turned on during the sixth consecutive detection period, the process returns to record the operating parameters of the air conditioning system before the compressor was turned on.

15. An air conditioning system, characterized in that, include: The control device for the air conditioning system as described in any one of claims 8 to 14.

16. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the control method of the air conditioning system according to any one of claims 1 to 7.

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