Control method and control device of air conditioner and air conditioner

Abstract

The invention provides an air conditioner control method and device and an air conditioner. The control method of the air conditioner comprises the steps that it is determined that the air conditioner is started, and fault detection is conducted on an electronic expansion valve of the air conditioner; under the condition that the electronic expansion valve is free of faults, the low pressure of the air conditioner and the temperature of an air suction port of a compressor in the air conditioner are obtained; and according to the low pressure and the temperature of the air suction port, working parameters of the air conditioner are controlled and adjusted so as to prevent liquid impact of the compressor. According to the control method and device of the air conditioner and the air conditioner, the liquid impact phenomenon of the compressor can be effectively prevented by monitoring the state of the electronic expansion valve in real time and calculating the air suction superheat degree, and therefore the reliability of a multi-split system is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical appliances, and in particular to a control method and a control device for an air conditioner, and an air conditioner. Background Art

[0002] In related technologies, air conditioners operating at low loads, starting at low temperatures, or using oil return defrost can easily experience liquid accumulation in the gas phase due to reduced heat exchange or low refrigerant circulation. This can lead to compressor hammering and damage. The electronic expansion valve is a key component in controlling refrigerant flow in air conditioners. If the valve fails, internal leakage can cause excessive refrigerant flow, also leading to compressor hammering. This hammering is a significant issue affecting the reliability of multi-split systems and poses a significant threat to the system. Summary of the Invention

[0003] The present invention provides an air conditioner control method, a control device, and an air conditioner to address the defects in the prior art and achieve the following technical effects: by real-time monitoring of the state of the electronic expansion valve and calculation of the suction superheat, the present invention can effectively prevent compressor liquid hammer, thereby significantly improving the reliability of the multi-split system.

[0004] A method for controlling an air conditioner according to a first embodiment of the present invention includes:

[0005] Determining that the air conditioner is turned on, and performing fault detection on an electronic expansion valve of the air conditioner;

[0006] When the electronic expansion valve is in good working order, obtaining the low pressure of the air conditioner and the air inlet temperature of the compressor in the air conditioner;

[0007] According to the low pressure and the air inlet temperature, operating parameters of the air conditioner are controlled and adjusted to prevent liquid hammer in the compressor.

[0008] According to one embodiment of the present invention, the step of controlling and adjusting the operating parameters of the air conditioner according to the low pressure and the air inlet temperature to prevent liquid hammer in the compressor specifically includes:

[0009] Calculating the suction superheat of the compressor according to the low pressure and the suction port temperature;

[0010] The liquid backflow risk at the suction port of the compressor is determined according to the range of the suction superheat, and the operating parameters of the air conditioner are controlled and adjusted to eliminate the liquid backflow risk.

[0011] According to one embodiment of the present invention, the step of determining the risk of liquid backflow at the suction port of the compressor based on the range of the suction superheat, and controlling and adjusting the operating parameters of the air conditioner to eliminate the risk of liquid backflow specifically includes:

[0012] When the suction superheat is less than or equal to a first set superheat, it is determined that the suction port has a risk of liquid backflow, and the electronic expansion valve is controlled to decrease, the compressor frequency is controlled to decrease, and the on-off valve located downstream of the liquid outlet of the gas-liquid separator is controlled to be in a closed state until the suction superheat exceeds the first set superheat;

[0013] Alternatively, when the suction air superheat is greater than the first set superheat, it is determined that there is no risk of liquid return at the suction port, and the air conditioner is controlled to maintain the original operating parameters.

[0014] According to one embodiment of the present invention, in the steps of controlling the electronic expansion valve to decrease and controlling the compressor frequency to decrease, the electronic expansion valve remains unchanged after being reduced to the minimum set opening, and the compressor frequency remains unchanged after being reduced to the minimum set frequency.

[0015] According to one embodiment of the present invention, after controlling and adjusting the operating parameters of the air conditioner according to the low pressure and the air inlet temperature to prevent the compressor from liquid hammer, the method further includes:

[0016] After determining that the air conditioner has been running continuously for a set period of time according to the original operating parameters, obtaining the low pressure and the air intake temperature again and calculating the air intake superheat;

[0017] The operating parameters of the air conditioner are adjusted according to the range of the suction air superheat.

[0018] According to one embodiment of the present invention, the step of adjusting the operating parameters of the air conditioner according to the range of the suction air superheat specifically includes:

[0019] When the suction superheat is greater than a second set superheat, the opening of the electronic expansion valve is controlled to increase, the frequency of the compressor is controlled to increase, and the switch valve is controlled to be in an open state;

[0020] When the suction superheat is less than or equal to the second set superheat, the liquid backflow risk of the suction port is determined again based on the comparison result of the suction superheat and the first set superheat, and the operating parameters of the air conditioner are controlled and adjusted to eliminate the liquid backflow risk.

[0021] According to one embodiment of the present invention, the step of performing fault detection on the electronic expansion valve of the air conditioner specifically includes:

[0022] determining that the air conditioner is turned on and in a heating mode, controlling the compressor of the air conditioner to maintain a set frequency unchanged, the fan to maintain a set speed unchanged, and controlling the electronic expansion valve to perform an opening increase operation to increase its opening;

[0023] After the opening degree increasing operation is completed, obtaining a first pressure change value of the high pressure of the air conditioner before and after the opening degree increasing operation is performed, a first power change value of the frequency of the compressor before and after the opening degree increasing operation is performed, and a first temperature change value of the exhaust temperature of the compressor before and after the opening degree increasing operation is performed;

[0024] Whether the electronic expansion valve fails is determined according to the first pressure change value, the first power change value, and the first temperature change value.

[0025] According to an embodiment of the present invention, the step of determining whether the electronic expansion valve has failed based on the first pressure change value, the first power change value, and the first temperature change value specifically includes:

[0026] When the first pressure change value, the first power change value, and the first temperature change value are all greater than zero, it is determined that the electronic expansion valve has no fault.

[0027] According to an embodiment of the present invention, the step of determining whether the electronic expansion valve has failed based on the first pressure change value, the first power change value, and the first temperature change value further includes:

[0028] When at least one of the first pressure change value, the first power change value, and the first temperature change value is less than or equal to zero, the compressor is controlled to continue to maintain a set frequency, the fan is controlled to maintain a set speed, and the electronic expansion valve is controlled to perform an opening reduction operation to reduce its opening;

[0029] After the opening degree reduction operation is completed, obtaining a second pressure change value of the high pressure of the air conditioner before and after the opening degree reduction operation is performed, a second power change value of the frequency of the compressor before and after the opening degree reduction operation is performed, and a second temperature change value of the exhaust temperature of the compressor before and after the opening degree reduction operation is performed;

[0030] Whether the electronic expansion valve fails is determined according to the second pressure change value, the second power change value, and the second temperature change value.

[0031] According to one embodiment of the present invention, the step of determining whether the electronic expansion valve has failed based on the second pressure change value, the second power change value, and the second temperature change value specifically includes:

[0032] When the second pressure change value, the second power change value, and the second temperature change value are all less than zero, it is determined that the electronic expansion valve has no fault;

[0033] When at least one of the second pressure change value, the second power change value, and the second temperature change value is greater than or equal to zero, it is determined that the electronic expansion valve has a fault, and an alarm is issued.

[0034] A control device for an air conditioner according to a second embodiment of the present invention includes:

[0035] a detection module, configured to determine that the air conditioner is turned on and perform fault detection on the electronic expansion valve of the air conditioner;

[0036] an acquisition module, configured to acquire the low pressure of the air conditioner and the air inlet temperature of the compressor in the air conditioner when the electronic expansion valve is not faulty;

[0037] The control module is used to control and adjust the operating parameters of the air conditioner according to the low pressure and the suction port temperature to prevent the compressor from liquid hammer.

[0038] According to an embodiment of the third aspect of the present invention, an air conditioner includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the air conditioner control method as described in the embodiment of the first aspect of the present invention is implemented.

[0039] The present invention provides a method for controlling an air conditioner, which has the following advantages over related technologies:

[0040] (1) Improved system reliability: By real-time monitoring of the electronic expansion valve status and calculating the suction superheat, the present invention can effectively prevent compressor liquid hammer, thereby significantly improving the reliability of the multi-connected system. Liquid hammer is a common cause of compressor damage and system failure. The control method of the present invention can significantly reduce the occurrence of such problems.

[0041] (2) Enhanced fault diagnosis capability: The present invention not only provides a control method but also includes a fault detection mechanism for the electronic expansion valve. This fault detection capability enables the system to promptly detect and address potential faults, thus avoiding refrigerant flow loss and compressor liquid hammer problems caused by electronic expansion valve failure.

[0042] (3) Intelligent Control: Utilizing advanced sensors and control algorithms, the present invention enables intelligent monitoring and regulation of the air conditioning system's operating status. This intelligent control method dynamically adjusts operating parameters based on real-time data, enabling the system to maintain optimal performance under varying operating conditions.

[0043] (4) Extending Equipment Life: By effectively avoiding liquid hammer, the present invention helps extend the service life of the compressor and other key components, reducing the number of equipment repairs and replacements, thereby reducing long-term operating costs.

[0044] (5) Improve energy efficiency: By precisely controlling the opening of the electronic expansion valve and the operating frequency of the compressor and other parameters, the present invention can optimize energy consumption and improve the energy efficiency ratio of the air-conditioning system while ensuring safe and stable operation of the system.

[0045] (6) Strong adaptability: The control method of the present invention is applicable to various multi-split and household air conditioning systems and has good adaptability and versatility. This means that it can function in different environments and conditions, providing users with a stable cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 This is one of the flow charts of the air conditioner control method provided by the present invention;

[0048] Figure 2 This is the second flow chart of the air conditioner control method provided by the present invention;

[0049] Figure 3 This is the third flow chart of the air conditioner control method provided by the present invention

[0050] Figure 4 1 is a schematic structural diagram of the control device of the air conditioner provided by the present invention;

[0051] Figure 5 It is a structural schematic diagram of the air conditioner provided by the present invention;

[0052] Figure 6 It is a structural schematic diagram of the electronic device provided by the present invention.

[0053] Reference numerals:

[0054] 1. Compressor; 2. Electronic expansion valve; 3. Outdoor heat exchanger; 4. Four-way valve; 5. Gas-liquid separator; 51. Switch valve; 52. Filter; 6. Oil separator; 7. Low-pressure pressure sensor; 8. High-pressure pressure sensor; 110. Detection module; 120. Acquisition module; 130. Control module. DETAILED DESCRIPTION

[0055] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0056] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0057] The following describes the control method, control device, and air conditioner of the air conditioner proposed by the present invention with reference to the accompanying drawings. Before describing the embodiments of the present invention in detail, the entire application scenario is described first. The control method, control device, electronic device, and computer-readable storage medium of the air conditioner of the embodiment of the present invention can be applied to the air conditioner locally, can be applied to the cloud platform in the Internet field, or other types of cloud platforms in the Internet field, or can also be applied to third-party devices. Among them, third-party devices may include various types such as mobile phones, tablet computers, notebooks, car computers, and other smart terminals.

[0058] The following description only takes the control method applicable to air conditioners as an example. It should be understood that the control method of the embodiment of the present invention can also be applied to cloud platforms and third-party devices.

[0059] like Figure 1 As shown, the air conditioner control method according to the first embodiment of the present invention includes:

[0060] Make sure the air conditioner is turned on and perform a fault check on the electronic expansion valve 2 of the air conditioner;

[0061] When the electronic expansion valve 2 is in good working order, the low pressure of the air conditioner and the air inlet temperature of the compressor 1 in the air conditioner are obtained;

[0062] According to the low pressure and the suction port temperature, the operating parameters of the air conditioner are controlled and adjusted to prevent liquid hammer in compressor 1.

[0063] In the air conditioner control method of this embodiment of the present invention, the normal operation of electronic expansion valve 2 is first ensured. Then, real-time monitoring of system pressure and temperature data is used to determine whether compressor 1 is at risk of liquid hammer. Based on this data, the system intelligently adjusts operating parameters, such as the opening of electronic expansion valve 2, the operating frequency of compressor 1, and the status of the oil return valve, to optimize refrigerant flow, prevent liquid hammer, and thus improve the reliability and efficiency of the air conditioning system.

[0064] Specifically, the air conditioner control method of the present invention operates as follows: When the user turns on the air conditioner, the system enters a standby state, preparing for subsequent fault detection and operational control. After the air conditioning system is started, the system automatically executes a fault detection routine for the electronic expansion valve 2. This ensures the proper functioning of the electronic expansion valve 2, a key component in controlling the refrigerant flow rate, and its operating status directly impacts the system's stability and efficiency. Fault detection may include checking parameters such as the valve's open / closed state, response speed, and current consumption to confirm its functionality.

[0065] If electronic expansion valve 2 passes fault detection, the system enters normal operation. At this point, the system uses the installed pressure and temperature sensors to obtain the current low-pressure pressure and the temperature at the suction port of compressor 1. This data is crucial for subsequent control strategies, as it helps the system determine whether there is a risk of liquid hammer.

[0066] Furthermore, based on the acquired pressure and temperature data, the system calculates the suction superheat (SH) and adjusts operating parameters accordingly. If the calculated SH is below a certain threshold (e.g., 4), indicating a risk of liquid hammer, the system will reduce the opening of electronic expansion valve 2, adjust the operating frequency of compressor 1, and control the opening and closing of the oil return valve to reduce the refrigerant flow rate, thereby preventing liquid hammer. If the SH is above the threshold, indicating no risk of liquid hammer, the system will appropriately increase the opening of electronic expansion valve 2 to maintain system efficiency.

[0067] As can be understood, the air conditioning control method of the present invention operates on the basis of real-time monitoring and intelligent control of key parameters within the air conditioning system. Specifically, by precisely controlling the refrigerant flow rate and the operating status of compressor 1, the system effectively avoids liquid hammering and ensures the stability and efficiency of the air conditioning system under various operating conditions. This method improves the overall performance of the air conditioning system through technical means, while also extending the service life of the equipment.

[0068] In related technologies, air conditioners operating at low loads, starting at low temperatures, or using oil return defrost can easily experience liquid accumulation in the gas phase due to reduced heat exchange or low refrigerant circulation. This can lead to compressor hammering and damage. The electronic expansion valve is a key component in controlling refrigerant flow in air conditioners. If the valve fails, internal leakage can cause excessive refrigerant flow, also leading to compressor hammering. This hammering is a significant issue affecting the reliability of multi-split systems and poses a significant threat to the system.

[0069] Therefore, in order to solve the technical defects existing in the above-mentioned related technologies, the present invention provides a control method for an air conditioner, which has the following advantages compared with the related technologies:

[0070] (1) Improved System Reliability: By real-time monitoring of the electronic expansion valve 2's status and calculating the suction superheat, the present invention effectively prevents liquid hammering in the compressor 1, thereby significantly improving the reliability of the VRF system. Liquid hammering is a common cause of compressor 1 damage and system failures. The control method of the present invention can significantly reduce the occurrence of such problems.

[0071] (2) Enhanced fault diagnosis capability: The present invention not only provides a control method, but also includes a fault detection mechanism for the electronic expansion valve 2. This fault detection capability enables the system to promptly detect and handle potential faults, thus avoiding the refrigerant flow loss and compressor 1 liquid hammer problems caused by the failure of the electronic expansion valve 2.

[0072] (3) Intelligent Control: Utilizing advanced sensors and control algorithms, the present invention enables intelligent monitoring and regulation of the air conditioning system's operating status. This intelligent control method dynamically adjusts operating parameters based on real-time data, enabling the system to maintain optimal performance under varying operating conditions.

[0073] (4) Extending Equipment Life: By effectively avoiding liquid hammer, the present invention helps to extend the service life of the compressor 1 and other key components, reducing the number of equipment repairs and replacements, thereby reducing long-term operating costs.

[0074] (5) Improve energy efficiency: By precisely controlling the opening of the electronic expansion valve 2 and the operating frequency of the compressor 1 and other parameters, the present invention can optimize energy consumption and improve the energy efficiency ratio of the air-conditioning system while ensuring safe and stable operation of the system.

[0075] (6) Strong adaptability: The control method of the present invention is applicable to various multi-split and household air conditioning systems and has good adaptability and versatility. This means that it can function in different environments and conditions, providing users with a stable cooling effect.

[0076] like Figure 2As shown, according to some embodiments of the present invention, the steps of controlling and adjusting the operating parameters of the air conditioner to prevent liquid hammer of the compressor 1 according to the low pressure and the suction port temperature specifically include:

[0077] Calculate the suction superheat of compressor 1 based on the low pressure and suction port temperature;

[0078] According to the range of the suction superheat, the risk of liquid backflow at the suction port of the compressor 1 is determined, and the operating parameters of the air conditioner are controlled and adjusted to eliminate the risk of liquid backflow.

[0079] In this embodiment, the system first obtains the current low-pressure pressure (Ps) and intake air temperature (Ts) from the low-pressure pressure sensor 7 and intake air temperature sensor installed in the air conditioning system. This data is then used to calculate the intake air superheat (SH), typically using the formula SH = Ts - Ps - t, where t is the saturation temperature corresponding to the low pressure. Intake air superheat is an important parameter for measuring the refrigerant condition at the intake air port of compressor 1, reflecting whether the refrigerant is overheated or contains excessive liquid components.

[0080] Based on the calculated suction superheat, the system then determines whether there is a risk of liquid flashback at the suction port of Compressor 1. This is typically determined within a certain range. For example, if the suction superheat is below a certain threshold (e.g., 4°C), the risk of liquid flashback is considered high, as it indicates that the refrigerant may contain excessive liquid components. Conversely, if the suction superheat is above the threshold (e.g., 4°C), the risk of liquid flashback is considered low.

[0081] Finally, based on the liquid backflow risk determined by the suction superheat, the system will take corresponding measures to adjust the operating parameters of the air conditioner (such as adjusting the opening of the electronic expansion valve 2 or the frequency of the compressor 1) to eliminate or reduce the liquid backflow risk.

[0082] In this way, through the above-mentioned intelligent control measures, the system can effectively manage the flow and state of the refrigerant, prevent liquid refrigerant from entering the compressor 1, thereby avoiding the occurrence of liquid hammer, protecting the compressor 1 from damage, and improving the stability and efficiency of the entire air-conditioning system.

[0083] like Figure 2 As shown, further, according to the range of the suction superheat, the liquid backflow risk at the suction port of the compressor 1 is determined, and the operating parameters of the air conditioner are controlled to eliminate the liquid backflow risk. The steps specifically include:

[0084] When the suction superheat is less than or equal to the first set superheat, it is determined that there is a risk of liquid backflow at the suction port, and the electronic expansion valve 2 is controlled to decrease, the frequency of the compressor 1 is controlled to decrease, and the switch valve 51 located downstream of the liquid outlet of the gas-liquid separator 5 is controlled to be in a closed state until the suction superheat is greater than the first set superheat;

[0085] Alternatively, when the suction superheat is greater than the first set superheat, it is determined that there is no risk of liquid return at the suction port, and the air conditioner is controlled to maintain the original operating parameters.

[0086] In this embodiment, when the calculated suction superheat is less than or equal to a preset first set superheat (e.g., 4°C), the system determines that there is a risk of liquid floodback at the suction port of compressor 1. This is because a lower suction superheat indicates that the temperature of the refrigerant at the suction port is close to its saturation temperature, increasing the possibility of liquid refrigerant entering compressor 1.

[0087] To reduce the refrigerant flow entering the evaporator, the system controls the electronic expansion valve 2 (LevA) to reduce its opening. This reduces the refrigerant flow and the risk of liquid refrigerant entering the compressor 1. The system also reduces the operating frequency of the compressor 1, that is, reduces its speed. This helps slow the refrigerant circulation speed and further reduces the possibility of liquid refrigerant entering the compressor 1. In addition, the switch valve 51 (SV1) located downstream of the liquid outlet of the gas-liquid separator 5 is controlled to be in the closed state. This prevents the liquid refrigerant from flowing out of the gas-liquid separator 5 and preventing it from entering the compressor 1.

[0088] The system will continuously monitor the suction superheat. When the suction superheat exceeds the first set superheat, it indicates that the risk of liquid floodback has been eliminated. At this point, the system will maintain the current control state until the suction superheat drops below the first set superheat again.

[0089] If the suction superheat is always greater than the first set superheat in subsequent monitoring, the system determines that there is no risk of liquid return at the suction port. At this time, the air conditioner will maintain the original operating parameters unchanged and continue to operate normally.

[0090] As described above, the above embodiment is based on real-time monitoring and intelligent control of the suction superheat. It determines whether there is a risk of liquid backflow by setting a specific superheat threshold, and intelligently adjusts the working state of the electronic expansion valve 2, the compressor 1 frequency and the switch valve 51 according to the judgment result, thereby effectively preventing liquid refrigerant from entering the compressor 1, thereby avoiding liquid hammer, protecting the compressor 1 from damage, and ensuring stable and efficient operation of the air-conditioning system.

[0091] In some specific embodiments, in the steps of controlling the electronic expansion valve 2 to decrease and controlling the frequency of the compressor 1 to decrease, the electronic expansion valve 2 remains unchanged after decreasing to the minimum set opening, and the frequency of the compressor 1 remains unchanged after decreasing to the minimum set frequency.

[0092] It's understood that when the system determines there's a risk of liquid backflow at the intake port of compressor 1, it instructs electronic expansion valve 2 (LevA) to begin decreasing its opening. The opening of electronic expansion valve 2 is gradually reduced until it reaches its minimum setting. Once the minimum opening is reached, the opening of electronic expansion valve 2 remains unchanged, regardless of whether the intake superheat decreases further. This ensures that while the system reduces refrigerant flow, it doesn't overly restrict flow and affect the normal operation of the air conditioning system. For example, the minimum setting could be 32 steps.

[0093] Similar to the control of electronic expansion valve 2, the system also adjusts the operating frequency of compressor 1. When the suction superheat indicates a risk of liquid floodback, the system reduces the operating frequency of compressor 1. The frequency decreases gradually until it reaches a preset minimum set frequency. At this minimum frequency, compressor 1 operates at its lowest speed. Similar to electronic expansion valve 2, even if the suction superheat improves, the frequency of compressor 1 remains constant after it reaches the minimum set frequency. For example, the minimum set frequency could be 30 Hz.

[0094] In this way, the above embodiment can maintain basic operation of the air conditioning system while ensuring that compressor 1 is not damaged by liquid refrigerant backflow. In other words, by controlling the frequency of electronic expansion valve 2 and compressor 1 to the minimum set value, the system can still maintain a certain cooling capacity while dealing with the risk of liquid backflow, avoiding system performance degradation or shutdown caused by over-adjustment.

[0095] like Figure 2 As shown, according to some embodiments of the present invention, after controlling and adjusting the operating parameters of the air conditioner according to the low pressure and the suction port temperature to prevent the compressor 1 from liquid hammer, the method further includes:

[0096] After confirming that the air conditioner has been running continuously for the set time according to the original working parameters, obtain the low pressure and suction port temperature again and calculate the suction superheat;

[0097] Adjust the operating parameters of the air conditioner according to the range of the suction superheat.

[0098] like Figure 2 As shown, further, the step of adjusting the operating parameters of the air conditioner according to the range of the suction air superheat degree specifically includes:

[0099] When the suction superheat is greater than the second set superheat, the opening of the electronic expansion valve 2 is controlled to increase, the frequency of the compressor 1 is controlled to increase, and the switch valve 51 is controlled to be in the open state;

[0100] When the suction superheat is less than or equal to the second set superheat, the liquid backflow risk of the suction port is judged again based on the comparison result of the suction superheat and the first set superheat, and the operating parameters of the air conditioner are controlled and adjusted to eliminate the liquid backflow risk.

[0101] With respect to the above embodiment, it is understood that the process of controlling the air conditioning operating parameters to prevent liquid hammer in the compressor 1 includes not only adjusting the current state, but also a cyclic process of periodically checking and adjusting the air conditioning system. The following is an introduction to the specific steps of the control process in the above embodiment:

[0102] After the air conditioning system adjusts its operating parameters based on the current low-pressure and intake air temperature, it will continue to operate at the original parameters for a set period of time. This period allows you to observe the actual effect of the adjusted operating parameters on the system. After this period, the system will re-obtain the low-pressure and intake air temperature and recalculate the intake air superheat.

[0103] Afterwards, the system decides whether further adjustment of operating parameters is required based on the latest suction superheat value.

[0104] If the calculated suction superheat exceeds the second set superheat (typically a higher value than the first set superheat, such as 6Hz), the system determines that the current refrigerant flow may be insufficient to meet the cooling demand. Therefore, the system takes the following measures: Increase the opening of electronic expansion valve 2 to allow more refrigerant to flow into the evaporator; increase the operating frequency of compressor 1 to increase the refrigerant circulation speed; and open on-off valve 51 to ensure smooth refrigerant flow from gas-liquid separator 5 to maintain normal system operation.

[0105] If the suction superheat is less than or equal to the second set superheat, the system will again determine whether there is a risk of liquid floodback based on the comparison result with the first set superheat. If the suction superheat is still lower than the first set superheat, indicating a risk of liquid floodback, the system will repeat the previous steps, reducing the opening of electronic expansion valve 2 and the frequency of compressor 1, and closing on-off valve 51 to prevent liquid hammer. If the suction superheat is higher than the first set superheat, indicating no risk of liquid floodback, the system may maintain the current operating parameters or make minor adjustments as needed.

[0106] Thus, the embodiments of the present invention periodically monitor and adjust the operating parameters of the air conditioning system, ensuring that the system effectively prevents compressor 1 from liquid hammer under varying operating conditions while still meeting cooling requirements. This approach not only improves the system's adaptability and stability, but also optimizes energy efficiency, ensuring the long-term stable operation of the air conditioning system. Through this dynamic adjustment mechanism, the system can automatically adapt to changes in the environment and operating conditions, providing users with a consistently comfortable environment.

[0107] like Figure 3 As shown, according to some embodiments of the present invention, the steps of performing fault detection on the electronic expansion valve 2 of the air conditioner specifically include:

[0108] Determining that the air conditioner is turned on and in heating mode, the compressor 1 of the air conditioner is controlled to maintain a set frequency unchanged, the fan is controlled to maintain a set speed unchanged, and the electronic expansion valve 2 is controlled to perform an opening increase operation to increase its opening;

[0109] After the opening degree increasing operation is completed, obtaining a first pressure change value of the high pressure of the air conditioner before and after the opening degree increasing operation is performed, a first power change value of the frequency of the compressor 1 before and after the opening degree increasing operation is performed, and a first temperature change value of the exhaust temperature of the compressor 1 before and after the opening degree increasing operation is performed;

[0110] Whether the electronic expansion valve 2 fails is determined according to the first pressure change value, the first power change value, and the first temperature change value.

[0111] In this embodiment, when the air conditioner is turned on and in heating mode, the system controls compressor 1 to maintain a set frequency and fan speed. Furthermore, the system instructs electronic expansion valve 2 to increase its opening. This operation simulates the need for increased flow rate that electronic expansion valve 2 might encounter in actual operation, thereby testing its responsiveness and functionality.

[0112] After the electronic expansion valve 2's opening degree increase operation is completed, the system obtains changes in the high-pressure pressure, compressor 1 frequency, and exhaust gas temperature. Specifically, the system compares the high-pressure pressure (first pressure change), compressor 1 frequency (first power change), and exhaust gas temperature (first temperature change) before and after the opening degree increase operation. These changes are key indicators for evaluating the performance of the electronic expansion valve 2.

[0113] The system then analyzes the operating status of electronic expansion valve 2 based on the acquired first pressure change, first power change, and first temperature change values. If the changes in pressure, power, and temperature conform to the expected pattern—that is, an increase in the opening leads to an increase in high-pressure pressure, an increase in compressor 1 power, and an increase in exhaust temperature—then electronic expansion valve 2 can be considered to be operating normally. If these changes do not conform to expectations, or if no significant changes are observed, this may indicate a malfunction in electronic expansion valve 2.

[0114] This fault detection method allows the system to promptly identify potential problems with the electronic expansion valve 2 and repair or replace it before the problem affects the normal operation of the air conditioning system. This preventative maintenance strategy helps improve system reliability and efficiency, reduces the risk of unplanned downtime, and ensures that users enjoy continuous and stable air conditioning service.

[0115] like Figure 3 As shown, in some embodiments of the present invention, the step of determining whether the electronic expansion valve 2 has a fault according to the first pressure change value, the first power change value, and the first temperature change value specifically includes:

[0116] When the first pressure change value, the first power change value, and the first temperature change value are all greater than zero, it is determined that the electronic expansion valve 2 has no fault.

[0117] In this embodiment, the system checks whether the first pressure change value, the first power change value, and the first temperature change value are all greater than zero. If all three change values ​​are positive, i.e., the high-pressure pressure has increased, the compressor 1 power has increased, and the exhaust gas temperature has increased, this generally means that the electronic expansion valve 2 has correctly responded to the command to increase its opening degree, and the system parameters have subsequently changed as expected.

[0118] Based on the above analysis, if all three change values ​​are greater than zero, the system determines that there is no fault in electronic expansion valve 2. This is a positive indication that electronic expansion valve 2 is functioning properly and meeting the air conditioning system's refrigerant flow control requirements in heating mode.

[0119] like Figure 3 As shown, in other embodiments of the present invention, the step of determining whether the electronic expansion valve 2 has failed according to the first pressure change value, the first power change value, and the first temperature change value further includes:

[0120] When at least one of the first pressure change value, the first power change value, and the first temperature change value is less than or equal to zero, the compressor 1 is controlled to continue to maintain the set frequency unchanged, the fan is controlled to maintain the set speed unchanged, and the electronic expansion valve 2 is controlled to perform an opening reduction operation to reduce its opening;

[0121] After the opening degree reduction operation is completed, obtaining a second pressure change value of the high pressure of the air conditioner before and after the opening degree reduction operation is performed, a second power change value of the frequency of the compressor 1 before and after the opening degree reduction operation is performed, and a second temperature change value of the exhaust temperature of the compressor 1 before and after the opening degree reduction operation is performed;

[0122] Whether the electronic expansion valve 2 fails is determined according to the second pressure change value, the second power change value, and the second temperature change value.

[0123] In this embodiment, after performing an opening increase operation, the system analyzes the first pressure change, the first power change, and the first temperature change. If at least one of the change values ​​in the first step is less than or equal to zero, this may indicate a problem with electronic expansion valve 2. In this case, the system proceeds to the next step, controlling electronic expansion valve 2 to decrease its opening. At this point, the system controls compressor 1 to maintain a set frequency and fan speed, while simultaneously instructing electronic expansion valve 2 to decrease its opening. This operation tests the responsiveness and functionality of electronic expansion valve 2 when reducing flow.

[0124] Subsequently, after the opening degree reduction operation is completed, the system obtains new change values ​​of the high pressure pressure, the compressor 1 frequency, and the exhaust temperature, namely, the second pressure change value, the second power change value, and the second temperature change value.

[0125] Finally, the system further determines the status of electronic expansion valve 2 based on the second set of changing values. If these values ​​show a pattern consistent with a reduced opening operation—namely, a drop in high-pressure pressure, a reduction in compressor 1 power, and a decrease in exhaust temperature—then it can be assumed that electronic expansion valve 2 is functioning properly when the flow rate is reduced. If these values ​​do not show the expected changes or the changes do not conform to the pattern, the system may determine that electronic expansion valve 2 has failed.

[0126] In summary, this step-by-step detection method allows the system to more accurately assess the operating status of the electronic expansion valve 2, both when increasing and decreasing the flow rate. This method helps ensure the reliability of the electronic expansion valve 2, thereby guaranteeing the stable operation of the entire air conditioning system. If the electronic expansion valve 2 is ultimately determined to be faulty, the system will take necessary repair or replacement measures to avoid possible performance degradation or system failure.

[0127] like Figure 3 As shown, further, the step of determining whether the electronic expansion valve 2 has a fault according to the second pressure change value, the second power change value and the second temperature change value specifically includes:

[0128] When the second pressure change value, the second power change value, and the second temperature change value are all less than zero, it is determined that the electronic expansion valve 2 has no fault;

[0129] When at least one of the second pressure change value, the second power change value, and the second temperature change value is greater than or equal to zero, it is determined that the electronic expansion valve 2 has a fault, and an alarm is issued.

[0130] The control device of the air conditioner provided by the present invention is described below. The control device of the air conditioner described below and the control method of the air conditioner described above can be referred to each other.

[0131] like Figure 4 As shown, the control device of the air conditioner according to the second embodiment of the present invention includes:

[0132] The detection module 110 is used to determine whether the air conditioner is turned on and perform fault detection on the electronic expansion valve 2 of the air conditioner;

[0133] The acquisition module 120 is used to obtain the low pressure of the air conditioner and the air inlet temperature of the compressor 1 in the air conditioner when the electronic expansion valve 2 is not faulty;

[0134] The control module 130 is used to control and adjust the operating parameters of the air conditioner according to the low pressure and the suction port temperature to prevent the compressor 1 from liquid hammer.

[0135] like Figure 5 As shown, the air conditioner according to the third embodiment of the present invention includes a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the program, the air conditioner control method described in the first embodiment of the present invention is implemented.

[0136] like Figure 5 As shown, the air conditioner further includes an electronic expansion valve 2, an outdoor heat exchanger 3, a four-way valve 4, a gas-liquid separator 5, an oil separator 6, and a compressor 1, which are connected via a refrigerant pipeline. A switch valve 51 and a filter 52 are provided downstream of the liquid outlet of the gas-liquid separator 5. A low-pressure sensor 7 is provided between the four-way valve 4 and the inlet of the gas-liquid separator 5 to detect the low pressure. A high-pressure sensor 8 is provided between the four-way valve 4 and the outlet of the oil separator 6 to detect the high pressure.

[0137] Figure 6 An example of a physical structure diagram of an electronic device is shown below. Figure 6 As shown, the electronic device may include: a processor 810, a communications interface 820, a memory 830, and a communications bus 840, wherein the processor 810, the communications interface 820, and the memory 830 communicate with each other via the communications bus 840. The processor 810 may call logic instructions in the memory 830 to execute an air conditioner control method, which includes: determining that the air conditioner is turned on and performing fault detection on the air conditioner's electronic expansion valve 2; if the electronic expansion valve 2 is not faulty, obtaining the air conditioner's low pressure and the air intake temperature of the air conditioner's compressor 1; and controlling and adjusting the air conditioner's operating parameters based on the low pressure and the air intake temperature to prevent liquid hammer in the compressor 1.

[0138] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0139] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the air conditioner control method provided by the above methods, which includes: determining that the air conditioner is turned on, and performing fault detection on the electronic expansion valve 2 of the air conditioner; when the electronic expansion valve 2 is not faulty, obtaining the low pressure of the air conditioner and the intake port temperature of the compressor 1 in the air conditioner; and controlling and adjusting the working parameters of the air conditioner according to the low pressure and the intake port temperature to prevent liquid hammer of the compressor 1.

[0140] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it is implemented to execute the air conditioner control method provided by the above methods, the method including: determining that the air conditioner is turned on, and performing fault detection on the electronic expansion valve 2 of the air conditioner; when the electronic expansion valve 2 is not faulty, obtaining the low pressure of the air conditioner and the intake port temperature of the compressor 1 in the air conditioner; and controlling and adjusting the working parameters of the air conditioner according to the low pressure and the intake port temperature to prevent liquid hammer of the compressor 1.

[0141] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. That is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0142] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus the necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or certain parts of the embodiment.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for controlling an air conditioner, characterized in that: include: Determining that the air conditioner is turned on, and performing fault detection on an electronic expansion valve of the air conditioner; When the electronic expansion valve is in good working order, obtaining the low pressure of the air conditioner and the air inlet temperature of the compressor in the air conditioner; According to the low pressure and the air inlet temperature, operating parameters of the air conditioner are controlled and adjusted to prevent liquid hammer in the compressor.

2. The air conditioner control method according to claim 1, characterized in that: The step of controlling and adjusting the operating parameters of the air conditioner according to the low pressure and the air inlet temperature to prevent the compressor from liquid hammer specifically includes: Calculating the suction superheat of the compressor according to the low pressure and the suction port temperature; The liquid backflow risk at the suction port of the compressor is determined according to the range of the suction superheat, and the operating parameters of the air conditioner are controlled and adjusted to eliminate the liquid backflow risk.

3. The air conditioner control method according to claim 2, characterized in that: The step of determining the risk of liquid backflow at the suction port of the compressor according to the range of the suction superheat, and controlling and adjusting the operating parameters of the air conditioner to eliminate the risk of liquid backflow specifically includes: When the suction superheat is less than or equal to a first set superheat, it is determined that the suction port has a risk of liquid backflow, and the electronic expansion valve is controlled to decrease, the compressor frequency is controlled to decrease, and the on-off valve located downstream of the liquid outlet of the gas-liquid separator is controlled to be in a closed state until the suction superheat exceeds the first set superheat; Alternatively, when the suction air superheat is greater than the first set superheat, it is determined that there is no risk of liquid return at the suction port, and the air conditioner is controlled to maintain the original operating parameters.

4. The air conditioner control method according to claim 3, characterized in that: In the steps of controlling the electronic expansion valve to decrease and controlling the compressor frequency to decrease, the electronic expansion valve remains unchanged after decreasing to the minimum set opening, and the compressor frequency remains unchanged after decreasing to the minimum set frequency.

5. The air conditioner control method according to claim 3, characterized in that: After controlling and adjusting the operating parameters of the air conditioner according to the low pressure and the air inlet temperature to prevent the compressor from liquid hammer, the method further includes: After determining that the air conditioner has been running continuously for a set period of time according to the original operating parameters, obtaining the low pressure and the air intake temperature again and calculating the air intake superheat; The operating parameters of the air conditioner are adjusted according to the range of the suction air superheat.

6. The air conditioner control method according to claim 5, characterized in that: The step of adjusting the operating parameters of the air conditioner according to the range of the suction air superheat specifically includes: When the suction superheat is greater than a second set superheat, the opening of the electronic expansion valve is controlled to increase, the frequency of the compressor is controlled to increase, and the switch valve is controlled to be in an open state; When the suction superheat is less than or equal to the second set superheat, the liquid backflow risk of the suction port is determined again based on the comparison result of the suction superheat and the first set superheat, and the operating parameters of the air conditioner are controlled and adjusted to eliminate the liquid backflow risk.

7. The air conditioner control method according to any one of claims 1 to 6, characterized in that: The step of performing fault detection on the electronic expansion valve of the air conditioner specifically includes: determining that the air conditioner is turned on and in a heating mode, controlling the compressor of the air conditioner to maintain a set frequency unchanged, the fan to maintain a set speed unchanged, and controlling the electronic expansion valve to perform an opening increase operation to increase its opening; After the opening degree increasing operation is completed, obtaining a first pressure change value of the high pressure of the air conditioner before and after the opening degree increasing operation is performed, a first power change value of the frequency of the compressor before and after the opening degree increasing operation is performed, and a first temperature change value of the exhaust temperature of the compressor before and after the opening degree increasing operation is performed; Whether the electronic expansion valve fails is determined according to the first pressure change value, the first power change value, and the first temperature change value.

8. The air conditioner control method according to claim 7, characterized in that: The step of determining whether the electronic expansion valve has failed based on the first pressure change value, the first power change value, and the first temperature change value specifically includes: When the first pressure change value, the first power change value, and the first temperature change value are all greater than zero, it is determined that the electronic expansion valve has no fault.

9. The air conditioner control method according to claim 7, characterized in that: The step of determining whether the electronic expansion valve has a fault according to the first pressure change value, the first power change value, and the first temperature change value further includes: When at least one of the first pressure change value, the first power change value, and the first temperature change value is less than or equal to zero, the compressor is controlled to continue to maintain a set frequency, the fan is controlled to maintain a set speed, and the electronic expansion valve is controlled to perform an opening reduction operation to reduce its opening; After the opening degree reduction operation is completed, obtaining a second pressure change value of the high pressure of the air conditioner before and after the opening degree reduction operation is performed, a second power change value of the frequency of the compressor before and after the opening degree reduction operation is performed, and a second temperature change value of the exhaust temperature of the compressor before and after the opening degree reduction operation is performed; Whether the electronic expansion valve fails is determined according to the second pressure change value, the second power change value, and the second temperature change value.

10. The air conditioner control method according to claim 9, characterized in that: The step of determining whether the electronic expansion valve has failed based on the second pressure change value, the second power change value, and the second temperature change value specifically includes: When the second pressure change value, the second power change value, and the second temperature change value are all less than zero, it is determined that the electronic expansion valve has no fault; When at least one of the second pressure change value, the second power change value, and the second temperature change value is greater than or equal to zero, it is determined that the electronic expansion valve has a fault, and an alarm is issued.

11. A control device for an air conditioner, characterized in that: include: a detection module, configured to determine that the air conditioner is turned on and perform fault detection on the electronic expansion valve of the air conditioner; an acquisition module, configured to acquire the low pressure of the air conditioner and the air inlet temperature of the compressor in the air conditioner when the electronic expansion valve is not faulty; The control module is used to control and adjust the operating parameters of the air conditioner according to the low pressure and the suction port temperature to prevent the compressor from liquid hammer.

12. An air conditioner comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the air conditioner control method according to any one of claims 1 to 10 is implemented.

Images