Air conditioner control method, control device and air conditioner

Abstract

An air conditioner control method includes: detecting the compressor exhaust temperature during startup; determining whether a hold control, frequency reduction control, or forced shutdown protection condition is met; if so, executing the corresponding hold, frequency reduction, or forced shutdown protection; recording the number of frequency reduction and protection control events; executing exhaust protection control if either condition meets the exhaust protection condition; determining whether the compressor exhaust temperature again meets the frequency reduction control condition; if so, applying an exhaust temperature correction value to correct the boundary threshold of the hold control condition until the compressor operating frequency remains within a set range within a first set period, calculating the sum of the exhaust temperature correction values; and comparing the sum of the exhaust temperature correction values with multiple refrigerant status set values to determine the current refrigerant status. Also disclosed are an air conditioner control device and an air conditioner. The present invention can automatically identify a refrigerant shortage and its actual status, requires low data processing, and is minimally affected by changes in air conditioning load.

Description

Technical Field

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

[0002] The five main components of a refrigeration system are the refrigerant, compressor, evaporator, throttling device, and condenser. The refrigerant circulates in the system as a fluid, absorbing or releasing energy. Refrigerant can exist in three states within a refrigeration system: liquid (subcooled), vapor (superheated), and saturated (a mixture of liquid and gas). Saturated refrigerant consists of a mixture of liquid and vapor in any proportion. Superheated refrigerant exists entirely in vapor form, with the temperature exceeding the saturated evaporation temperature. Subcooled refrigerant exists entirely in liquid form, with the temperature below the saturated condensation temperature. Refrigerant absorbs heat when it transforms from liquid to vapor, and releases heat when it transforms from vapor to liquid. During refrigeration system operation, the majority of the refrigerant exists in the condenser and evaporator in either liquid or saturated vapor form. An ideal refrigerant must meet a variety of requirements, including the ability to carry a significant amount of heat during phase changes; safety, stability, and detectability; and excellent compression characteristics, environmental friendliness, and cost-effectiveness. Although most refrigerants have low or non-toxic toxicity, excessive leakage of refrigerants can cause harm to the human body because they are heavier than air and will displace the surrounding oxygen. In addition, insufficient or leaking refrigerants can also cause the refrigeration system's capacity to decline, affecting the stability of the equipment.

[0003] The prior art discloses various methods for detecting refrigerant leaks or shortages, particularly in air conditioners. One method relies on the difference between the indoor ambient temperature and the coil temperature. However, if the set temperature difference is large, this method can easily lead to misjudgments when the indoor ambient temperature and the set temperature are close. If the set temperature difference is small, detection is difficult and can be affected by the indoor fan speed. Another method, such as the one disclosed in Chinese invention patent (CN109323363A), involves: "Obtaining indoor and outdoor ambient temperatures; obtaining parameter thresholds based on the indoor and outdoor ambient temperatures; obtaining operating parameters of the air conditioner; scoring the air conditioner based on the operating parameters and the parameter thresholds to generate a score; and determining whether a refrigerant shortage fault has occurred based on the air conditioner score." This reference document provides a method for determining whether a refrigerant shortage fault has occurred based on the resulting score. By comparing the resulting scores for multiple scenarios with pre-set scoring criteria, accurate refrigerant leakage determination is achieved.

[0004] Although the above method can accurately determine whether a refrigerant leak occurs, it requires the processor's high data processing capabilities and has low applicability for economical products. Moreover, the entire system relies on the detection results of multiple sensors. If a hardware failure occurs in one of the sensors, it may cause deviations in the overall score and reduce the accuracy of the judgment result. Summary of the Invention

[0005] The present invention is based on the prior art that makes judgments based on the difference between the indoor ambient temperature and the coil temperature. However, if the set temperature difference is large, misjudgment is likely to occur when the indoor ambient temperature and the set temperature are close; if the set temperature difference is small, it is not easy to detect and is easily affected by the indoor fan speed. The final score values generated for multiple situations are compared with the preset score standards to determine whether the refrigerant has leaked. This requires the processor to have a high data processing capability, and the system as a whole relies on the detection results of multiple sensors, resulting in low robustness. A first aspect of the present invention provides an air conditioner control method.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0007] A method for controlling an air conditioner comprises the following steps:

[0008] Detect the compressor exhaust temperature during the normal startup of the air conditioner;

[0009] Determine whether the compressor exhaust temperature meets any one of a holding control condition, a frequency reduction control condition, or a forced shutdown protection condition; if so, execute the corresponding holding control, frequency reduction control, or forced shutdown protection for the compressor;

[0010] Recording the number of times the frequency reduction control is executed and the number of times the forced shutdown protection control is executed; if one of the frequency reduction control number and the protection control number meets the exhaust protection condition, executing the exhaust protection control;

[0011] When the exhaust protection control is executed: determining whether the exhaust temperature of the compressor meets the frequency reduction control condition again, and each time the frequency reduction control condition is met again, calling the exhaust temperature correction value once to correct the boundary threshold of the maintenance control condition until the compressor operating frequency remains in the set range within the first set period, and calculating the sum of the exhaust temperature correction values;

[0012] The sum of the exhaust temperature correction values is compared with a plurality of refrigerant state setting values to determine the current refrigerant state; the refrigerant state setting values correspond to a sufficient state, a first refrigerant insufficient state, and a second refrigerant insufficient state, respectively.

[0013] A second aspect of the present invention provides an air conditioner control device, the air conditioner control device comprising:

[0014] a sampling module configured to detect the compressor exhaust temperature during normal startup of the air conditioner;

[0015] a first determination module configured to determine whether the compressor exhaust temperature satisfies any one of a maintenance control condition, a frequency reduction control condition, or a forced shutdown protection condition;

[0016] a first execution module, configured to execute corresponding maintenance control, frequency reduction control or forced shutdown protection on the compressor when the exhaust temperature of the compressor meets any one of a maintenance control condition, a frequency reduction control condition or a forced shutdown protection condition;

[0017] a recording module configured to record the number of frequency reduction controls executed and the number of protection controls executed for forced shutdown protection control;

[0018] a second execution module configured to execute exhaust protection control when one of the frequency reduction control times and the protection control times meets an exhaust protection condition;

[0019] a second determination module configured to determine whether the compressor exhaust temperature meets the frequency reduction control condition again when performing exhaust protection control;

[0020] a calculation module configured to, each time the frequency reduction control condition is met again, call the exhaust temperature correction value to correct the boundary threshold of the maintenance control condition until the compressor operating frequency remains within the set range within a first set period, and calculate the sum of the exhaust temperature correction values; and

[0021] A determination module is configured to compare the sum of the exhaust temperature correction values with multiple refrigerant state setting values to determine the current refrigerant state; the refrigerant state setting values correspond to the sufficient state, the first refrigerant insufficient state and the second refrigerant insufficient state respectively.

[0022] A third aspect of the present invention provides an air conditioner, applying the following air conditioner control method: the air conditioner control method comprises the following steps:

[0023] Detect the compressor exhaust temperature during the normal startup of the air conditioner;

[0024] Determine whether the compressor exhaust temperature meets any one of a holding control condition, a frequency reduction control condition, or a forced shutdown protection condition; if so, execute the corresponding holding control, frequency reduction control, or forced shutdown protection for the compressor;

[0025] Recording the number of times the frequency reduction control is executed and the number of times the forced shutdown protection control is executed; if one of the frequency reduction control number and the protection control number meets the exhaust protection condition, executing the exhaust protection control;

[0026] When the exhaust protection control is executed: determining whether the exhaust temperature of the compressor meets the frequency reduction control condition again, and each time the frequency reduction control condition is met again, calling the exhaust temperature correction value once to correct the boundary threshold of the maintenance control condition until the compressor operating frequency remains in the set range within the first set period, and calculating the sum of the exhaust temperature correction values;

[0027] The sum of the exhaust temperature correction values is compared with a plurality of refrigerant state setting values to determine the current refrigerant state; the refrigerant state setting values correspond to a sufficient state, a first refrigerant insufficient state, and a second refrigerant insufficient state, respectively.

[0028] Compared with the prior art, the advantages and positive effects of the present invention are:

[0029] The present invention can determine the refrigerant status by using only one parameter, the compressor exhaust temperature. While protecting the compressor, it automatically identifies the situation of insufficient refrigerant and the actual status of the refrigerant. The required data processing amount is low, and the influence of changes in air-conditioning load is small. It has the advantages of high judgment accuracy and good practicality.

[0030] Other features and advantages of the present invention will become more apparent after reading the detailed description of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. 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.

[0032] Figure 1 A flow chart of the air conditioner control method provided by the present invention;

[0033] Figure 2 A flow chart for executing frequency reduction control;

[0034] Figure 3 Another flow chart for executing frequency reduction control;

[0035] Figure 4 Another flow chart for executing frequency reduction control;

[0036] Figure 5Another flow chart for executing frequency reduction control;

[0037] Figure 6 This is a schematic block diagram of the structure of the air conditioner control device provided by the present invention. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0039] The terms "first," "second," "third," and so on, in the description, claims, and drawings of the present invention are used to distinguish between different items, not to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof, represent non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0040] In the present invention, the phrase "embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. Those skilled in the art will appreciate that the embodiments described herein may be combined with other embodiments.

[0041] Based on the existing technology of judging based on the difference between the indoor ambient temperature and the coil temperature, there is a problem that if the set temperature difference is large, it is easy to make a misjudgment when the indoor ambient temperature and the set temperature are close; if the set temperature difference is small, it is difficult to detect and is easily affected by the indoor fan speed. The final score value generated for multiple situations is compared with the preset score standard to determine whether the refrigerant leaks. This requires the processor's high data processing capabilities. The system as a whole relies on the detection results of multiple sensors, and has low robustness. Figure 1The present invention provides an air conditioner control method. The air conditioner described herein delivers air with specific parameters into the room (supply air) and simultaneously removes a corresponding amount of air from the room (return air). The simultaneous operation of supply and return air maintains the desired indoor air condition. The supply air is pre-processed by air handling equipment. In addition to the typical heating and cooling processes, it may also include additional humidification, dehumidification, filtration, purification, and other treatment processes. The air conditioner utilizes a vapor compression refrigeration cycle, which includes a compressor, a throttling device, a condenser, an evaporator, and various auxiliary equipment such as storage, separation, and safety protection. The condenser cools and condenses the high-temperature, high-pressure refrigerant discharged from the compressor into a liquid. The heat released by the refrigerant in the condenser is removed by the cooling medium (water or air). The evaporator utilizes the evaporation (boiling) of the liquid refrigerant at low pressure, converting it into vapor and absorbing heat from the cooling medium to achieve cooling. The evaporator is the device in the refrigeration system that generates and outputs cooling capacity. The compressor is a variable capacity compressor. Air conditioners are equipped with a microprocessor that controls the compressor to continuously operate at different speeds based on the indoor load, achieving optimal control of the refrigeration system. Given the multivariable, nonlinear, and time-varying nature of air conditioning loads, conventional techniques typically use fuzzy control algorithms, PID control algorithms, a combination of fuzzy and PID control algorithms, or more precise mathematical models to calculate the compressor operating frequency under normal operating conditions.

[0042] like Figure 1 As shown, the air conditioner control method provided in this embodiment performs the following steps:

[0043] Step S11: Detecting the compressor exhaust temperature during the normal startup of the air conditioner.

[0044] Step S12: Determine whether the compressor exhaust temperature meets one of the following conditions: a hold control condition, a frequency reduction control condition, or a forced shutdown protection condition. Hold control refers to continuing to calculate and maintain the compressor operating frequency according to the algorithm or mathematical model stored in the processor, without actively intervening. Frequency reduction control refers to forcibly reducing the compressor operating frequency at a certain rate. Forced shutdown protection refers to shutting down the compressor. Excessively high compressor exhaust temperature can degrade the compressor's operating environment, potentially leading to overheating or overload. Therefore, pre-conditions for frequency reduction control and forced shutdown protection are set to identify any of these abnormalities.

[0045] Step S13: If the conditions are met, the system executes corresponding maintenance control, frequency reduction control, or forced shutdown protection for the compressor. Specifically, when the frequency reduction control or forced shutdown protection conditions are met, the system first proactively intervenes in the compressor's operating state to prevent irreversible damage to the compressor. It then intelligently determines the cause of the abnormal compressor exhaust temperature, eliminating the impact of minor, automatically repairable faults such as sensor communication anomalies.

[0046] Step S14: recording the number of times the frequency reduction control is performed and the number of times the forced shutdown protection control is performed.

[0047] Step S15: Determine whether any one of the recorded frequency reduction control times and protection control times meets the exhaust protection conditions. If both the frequency reduction control times and the protection control times do not meet the exhaust protection conditions, it means that the factors that caused the abnormal exhaust temperature have been automatically repaired or eliminated, and no intervention is performed, and the air conditioner operates normally; if the frequency reduction control times or the protection control times meet the exhaust protection conditions, it means that the system cannot repair the relevant problems by itself. This is most likely caused by insufficient refrigerant filling in the refrigeration cycle system. When the refrigerant filling amount is insufficient, even if the opening of the electronic expansion valve is increased to the maximum opening, the refrigerant flow rate cannot change, and the refrigerant vapor in the evaporator is overheated, causing the compressor suction temperature to increase, further causing the exhaust temperature to increase accordingly and cannot be self-repaired, and the exhaust protection control is executed.

[0048] Step S16: When executing exhaust protection control, the system first determines whether the compressor exhaust temperature again meets the frequency reduction control conditions. The purposes of executing exhaust protection are, first, to protect the compressor, second, to determine whether refrigerant insufficiency (refrigerant leakage) actually exists, and third, to determine the extent of the refrigerant insufficiency.

[0049] Step S17: If the frequency reduction control condition is met again, the exhaust temperature correction value is used to adjust the threshold of the maintenance control condition. Specifically, the exhaust temperature correction value is negative, and the threshold of the maintenance control condition after the correction is the sum of the threshold of the maintenance control condition before the correction and the exhaust temperature correction value. Simply put, the threshold of the maintenance control condition is reduced by a set amount, expanding the allowable range of the maintenance control condition.

[0050] Step S18: Determine whether the compressor operating frequency remains in the set range within the first set period. The set range is a relatively small range, and whether the compressor operating frequency is stable is measured by whether the compressor operating frequency remains in the set range; if the compressor operating frequency remains in the set range within the first set period, it means that under the current maintenance control conditions, the compressor can maintain normal operation, that is, maintain stable operation after reaching the set temperature; thus, it can be determined that the high compressor exhaust pressure is caused by insufficient refrigerant, not by hardware damage to the compressor itself. The first set period is to eliminate the impact of changes in the compressor operating frequency caused by changes in air-conditioning load. If the compressor operating frequency cannot be maintained in the set range within the first set period, the exhaust temperature correction value is called again to correct the boundary threshold of the maintenance control condition until the compressor operating frequency remains in the set range within the first set period.

[0051] Step S19: If the compressor operating frequency is maintained within the set interval within the first set period after one or more corrections are made to maintain the control condition, the sum of all the called exhaust gas temperature correction values is calculated.

[0052] Step S20: Compare the sum of the exhaust temperature correction values with multiple refrigerant status setting values to determine the current refrigerant status. The multiple refrigerant status setting values are preferably obtained by professionals in the field under experimental conditions and stored in advance in the microprocessor for easy access. The refrigerant status setting values correspond to a sufficient state, a first refrigerant insufficient state, and a second refrigerant insufficient state, respectively.

[0053] Through the above method, the refrigerant status can be confirmed by using only one parameter, the compressor exhaust temperature. While protecting the compressor, the insufficient refrigerant and the actual status of the refrigerant can be automatically identified. The required data processing amount is small, the influence of changes in air-conditioning load is small, the judgment accuracy is high, and the practicality is good.

[0054] In order to achieve optimal control of the compressor during the protection process, the frequency reduction control condition includes a first frequency reduction control condition and a second frequency reduction control condition.

[0055] like Figure 2 As shown, step S12-11: determine whether the compressor exhaust temperature meets the first frequency reduction control condition; step S12-12: if the first frequency reduction control condition is met, control the compressor to reduce the frequency according to the first set frequency reduction rate.

[0056] like Figure 3 As shown, step S12-21: determine whether the compressor exhaust temperature meets the second frequency reduction control condition; step S12-22: if the second frequency reduction control condition is met, control the compressor to operate at a frequency reduction rate according to the second set frequency reduction rate.

[0057] The first frequency reduction rate is less than the second frequency reduction rate. Specifically, the first set frequency reduction rate corresponds to slow frequency reduction, while the second set frequency reduction rate corresponds to fast frequency reduction. In some control scenarios requiring higher precision, the number of fast frequency reduction control executions and the number of forced shutdown protection control executions can be recorded and used as a condition for executing exhaust protection control.

[0058] like Figure 4 and Figure 5 As shown, the frequency reduction control process includes the following steps.

[0059] Step S12-31: Determine whether the compressor exhaust temperature meets the first frequency protection condition;

[0060] Step S12-32: If the first frequency protection condition is met, the compressor frequency is prohibited from decreasing and only the compressor frequency is allowed to increase.

[0061] Step S12-41: Determine whether the compressor exhaust temperature meets the second frequency protection condition;

[0062] Step S12-42: If the second frequency protection condition is met, the compressor frequency is controlled to increase according to the first set frequency increase rate.

[0063] The above process avoids excessive sacrifice of air conditioner performance during exhaust protection control, which would result in excessive degradation of user experience.

[0064] The lower limit thresholds for the hold control condition, the first frequency reduction control condition, the second frequency reduction control condition, and the forced shutdown protection condition increase in sequence. Assuming the lower limit threshold for the hold control condition is A, the lower limit threshold for the first frequency reduction control condition is B, the lower limit threshold for the second frequency reduction control condition is C, and the lower limit threshold for the forced shutdown protection condition is D, then the compressor exhaust temperature is greater than or equal to A and less than B, satisfying the hold control condition; the compressor exhaust temperature is greater than or equal to B and less than C, satisfying the first frequency reduction control condition; the compressor exhaust temperature is greater than or equal to C and less than D, satisfying the second frequency reduction control condition; and the compressor exhaust temperature is greater than or equal to D, satisfying the forced shutdown protection condition. The boundary thresholds for the hold control condition after correction are the sum of the lower limit threshold A before correction of the hold control condition and the exhaust temperature correction value.

[0065] During the frequency reduction control process, if the compressor exhaust temperature drops to less than or equal to the upper boundary threshold F of the first frequency protection condition, the first frequency protection condition is met and the compressor frequency is prohibited from decreasing. If the compressor exhaust temperature drops to less than or equal to the upper boundary threshold E of the second frequency protection condition, the second frequency protection condition is met and the compressor frequency is controlled to increase according to the first set frequency increase rate. The upper boundary threshold F of the first frequency protection condition and the upper boundary threshold E of the second frequency protection condition satisfy E<A<F<B<C<D. The exhaust temperature correction value is preferably set to -1°C, that is, the lower boundary threshold A before the control condition correction is maintained at a single decrease of 1°C.

[0066] Comparing the sum of the exhaust temperature correction values with multiple refrigerant status setpoints to determine the current refrigerant status specifically includes the following process: If the sum of the exhaust temperature correction values is less than the first refrigerant status setpoint, the current refrigerant status is relatively sufficient. This relatively sufficient status can be understood as a slightly insufficient refrigerant, but temporarily ensuring safe operation without requiring active intervention. If the sum of the exhaust temperature correction values is less than the second refrigerant status setpoint and greater than the first refrigerant status setpoint, the current refrigerant status is a first refrigerant shortage state. If the sum of the exhaust temperature correction values is greater than the second refrigerant status setpoint, the current refrigerant status is a second refrigerant shortage state. The refrigerant shortage in the second refrigerant shortage state is greater than the refrigerant shortage in the first refrigerant shortage state. For example, the first refrigerant shortage state corresponds to 80% of the marked amount, while the second refrigerant shortage state corresponds to 60% of the marked amount. When the relatively sufficient state is determined, the system indicates this with a green indicator light; when the first refrigerant shortage state is determined, the system indicates this with a yellow indicator light; and when the second refrigerant shortage state is determined, the system indicates this with a red indicator light, reminding the user to add refrigerant promptly.

[0067] The second aspect of the present invention provides an air conditioner control device. Figure 6 As shown, the air conditioner control device includes the following components.

[0068] The sampling module 11 is configured to detect the compressor exhaust temperature during the normal startup process of the air conditioner.

[0069] The first determination module 12 is configured to determine whether the compressor exhaust temperature satisfies any of the following conditions: a maintenance control condition, a frequency reduction control condition, or a forced shutdown protection condition. Maintenance control refers to continuing to calculate and maintain the compressor operating frequency according to an algorithm or mathematical model stored in the processor, without actively intervening in the calculation; frequency reduction control refers to forcibly controlling the compressor operating frequency to decrease at a certain rate; and forced shutdown protection refers to controlling the compressor to shut down. Excessively high compressor exhaust temperature can degrade the compressor's operating environment, potentially leading to overheating or overload. Therefore, pre-conditions for frequency reduction control and forced shutdown protection are set to identify any of these abnormalities.

[0070] The first execution module 13 is configured to execute the corresponding maintenance control, frequency reduction control, or forced shutdown protection for the compressor when the compressor exhaust temperature meets any of the following conditions: maintenance control, frequency reduction control, or forced shutdown protection. Specifically, when the frequency reduction control or forced shutdown protection conditions are met, the module first proactively intervenes in the compressor's operating state to prevent irreversible damage to the compressor. It then intelligently determines the cause of the abnormal compressor exhaust temperature, eliminating the impact of minor, automatically repairable faults such as sensor communication anomalies.

[0071] The recording module 14 is configured to record the number of frequency reduction controls executed and the number of forced shutdown protection controls executed.

[0072] The second execution module 15 is configured to execute exhaust protection control when one of the frequency reduction control times and the protection control times meets the exhaust protection condition. If both the frequency reduction control times and the protection control times do not meet the exhaust protection condition, it means that the factors causing the abnormal exhaust temperature have been automatically repaired or eliminated, and no intervention is performed, and the air conditioner operates normally; if the frequency reduction control times or the protection control times meet the exhaust protection condition, it means that the system cannot repair the relevant problems by itself. This is most likely caused by insufficient refrigerant filling in the refrigeration cycle system. When the refrigerant filling amount is insufficient, even if the opening of the electronic expansion valve is increased to the maximum opening, the refrigerant flow rate cannot change, and the refrigerant vapor in the evaporator is overheated, causing the compressor suction temperature to increase, further causing the exhaust temperature to increase accordingly and cannot be self-repaired, and the exhaust protection control is executed.

[0073] The second determination module 16 is configured to determine whether the compressor exhaust temperature again meets the frequency reduction control conditions during the execution of exhaust protection control. The purposes of executing exhaust protection control are, first, to protect the compressor, second, to determine whether there is a true refrigerant shortage (refrigerant leakage), and third, to determine the extent of the refrigerant shortage.

[0074] The calculation module 17 is configured to call the exhaust temperature correction value to correct the boundary threshold of the maintenance control condition each time the frequency reduction control condition is met again until the compressor operating frequency remains in the set range within the first set period, and calculate the sum of the exhaust temperature correction values. Specifically, the exhaust temperature correction value is a negative value, and the boundary threshold of the maintenance control condition after correction is the sum of the boundary threshold before correction and the exhaust temperature correction value. In simple terms, the boundary threshold of the maintenance control condition is reduced by the set amplitude, and the allowable range of the maintenance control condition is expanded. The set range is a relatively small range, and whether the compressor operating frequency remains in the set range is measured to determine whether the compressor operating frequency is stable; if the compressor operating frequency remains in the set range within the first set period, it means that under the current maintenance control conditions, the compressor can maintain normal operation, that is, maintain stable operation after reaching the set temperature; thus, it can be determined that the excessively high compressor exhaust pressure is caused by insufficient refrigerant, not by damage to the compressor hardware itself. The first set period is to eliminate the impact of changes in the compressor operating frequency caused by changes in air-conditioning load. If the compressor operating frequency cannot be maintained in the set range within the first set period, the exhaust temperature correction value is called again to correct the boundary threshold of the control condition until the compressor operating frequency is maintained in the set range within the first set period.

[0075] Determination module 18 is configured to compare the sum of the exhaust temperature correction value with a plurality of refrigerant state set values to determine the current refrigerant state; the refrigerant state set values correspond to a sufficient state, a first refrigerant insufficient state, and a second refrigerant insufficient state, respectively. The plurality of refrigerant state set values are preferably obtained by professionals skilled in the art under experimental conditions and stored in advance in the microprocessor for easy access. The refrigerant state set values correspond to a sufficient state, a first refrigerant insufficient state, and a second refrigerant insufficient state, respectively.

[0076] The control device can confirm the refrigerant status only by using the compressor exhaust temperature, and automatically and accurately identify the situation of insufficient refrigerant while protecting the compressor.

[0077] Specifically, the frequency reduction control conditions include: a first frequency reduction control condition and a second frequency reduction control condition;

[0078] The first execution module is configured to control the compressor to operate at a first set frequency reduction rate when the compressor exhaust temperature meets the first frequency reduction control condition; and control the compressor to operate at a second set frequency reduction rate when the compressor exhaust temperature meets the second frequency reduction control condition;

[0079] The first frequency reduction rate is less than the second frequency reduction rate. Specifically, the first set frequency reduction rate corresponds to slow frequency reduction, while the second set frequency reduction rate corresponds to fast frequency reduction. In some control scenarios requiring higher precision, the number of fast frequency reduction control executions and the number of forced shutdown protection control executions can be recorded and used as a condition for executing exhaust protection control.

[0080] Assuming the lower limit threshold of the hold control condition is A, the lower limit threshold of the first frequency reduction control condition is B, the lower limit threshold of the second frequency reduction control condition is C, and the lower limit threshold of the forced shutdown protection condition is D, then the compressor exhaust temperature is greater than or equal to A and less than B to meet the hold control condition; the compressor exhaust temperature is greater than or equal to B and less than C to meet the first frequency reduction control condition; the compressor exhaust temperature is greater than or equal to C and less than D to meet the second frequency reduction control condition; and the compressor exhaust temperature is greater than or equal to D to meet the forced shutdown protection condition. The corrected limit threshold of the hold control condition is the sum of the lower limit threshold A before the hold control condition is corrected and the corrected exhaust temperature value.

[0081] In order to avoid sacrificing too much air conditioning performance, during the frequency reduction control process, the first execution module is configured to prohibit the compressor frequency from decreasing when the compressor exhaust temperature meets the first frequency protection condition; and to control the compressor frequency to increase according to the first set frequency increase rate when the compressor exhaust temperature meets the second frequency protection condition. If the compressor exhaust temperature drops to less than or equal to the upper boundary threshold F of the first frequency protection condition, the first frequency protection condition is met and the compressor frequency is prohibited from decreasing; if the compressor exhaust temperature drops to less than or equal to the upper boundary threshold E of the second frequency protection condition, the second frequency protection condition is met and the compressor frequency is controlled to increase according to the first set frequency increase rate. The upper boundary threshold F of the first frequency protection condition and the upper boundary threshold E of the second frequency protection condition satisfy E<A<F<B<C<D. The exhaust temperature correction value is preferably set to -1°C, that is, the lower boundary threshold A before the control condition correction is maintained at a single decrease of 1°C.

[0082] The determination module is specifically configured as follows: when the sum of the exhaust temperature correction values is less than the first refrigerant state setting value, the current refrigerant state is determined to be a relatively sufficient state; when the sum of the exhaust temperature correction values is less than the second refrigerant state setting value and greater than the first refrigerant state setting value, the current refrigerant state is determined to be a first refrigerant shortage state; when the sum of the exhaust temperature correction values is greater than the second refrigerant state setting value, the current refrigerant state is determined to be a second refrigerant shortage state; wherein the refrigerant shortage amount in the second refrigerant shortage state is greater than the refrigerant shortage amount in the first refrigerant shortage state. A relatively sufficient state can be understood as a refrigerant state that is slightly insufficient, but temporarily ensures safe operation without active intervention. For example, the first refrigerant shortage state can correspond to 80% of the marked amount, and the second refrigerant shortage state corresponds to 60% of the marked amount. When a relatively sufficient state is determined, the system can indicate this with a green indicator light; when the first refrigerant shortage state is determined, the system can indicate this with a yellow indicator light; when the second refrigerant shortage state is determined, the system can indicate this with a red indicator light, reminding the user to add refrigerant in time.

[0083] The present application also provides an air conditioner that utilizes the aforementioned air conditioner control method. The specific steps of the air conditioner control method are described in detail in the aforementioned embodiment and in the accompanying drawings. These steps will not be repeated here; an air conditioner utilizing the aforementioned air conditioner control method can achieve the same technical effects.

[0084] An embodiment of the present application also provides a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, and the computer program enables the air conditioner to execute part or all of the steps of any method described in the above method embodiments.

[0085] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0086] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely schematic, and the division of the above-mentioned units or modules is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical or other forms.

[0087] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one physical space, or may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0088] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A method for controlling an air conditioner, characterized in that: The following steps are involved: Detect the compressor exhaust temperature during the normal startup of the air conditioner; Determining whether the compressor exhaust temperature meets any one of a maintenance control condition, a frequency reduction control condition, or a forced shutdown protection condition; If the conditions are met, the compressor will be kept under control, frequency-reducing controlled or forced to stop for protection. Recording the number of frequency reduction controls performed and the number of forced shutdown protection controls performed; If one of the frequency reduction control times and the protection control times meets the exhaust protection condition, performing exhaust protection control; When the exhaust protection control is executed: determining whether the exhaust temperature of the compressor meets the frequency reduction control condition again, and each time the frequency reduction control condition is met again, calling the exhaust temperature correction value once to correct the boundary threshold of the maintenance control condition until the compressor operating frequency remains in the set range within the first set period, and calculating the sum of the exhaust temperature correction values; The sum of the exhaust temperature correction values is compared with multiple refrigerant state setting values to determine the current refrigerant state; if the sum of the exhaust temperature correction values is less than the first refrigerant state setting value, the current refrigerant state is a relatively sufficient state; if the sum of the exhaust temperature correction values is less than the second refrigerant state setting value and greater than the first refrigerant state setting value, the current refrigerant state is a first refrigerant insufficient state; if the sum of the exhaust temperature correction values is greater than the second refrigerant state setting value, the current refrigerant state is a second refrigerant insufficient state; wherein the refrigerant shortage amount of the second refrigerant insufficient state is greater than the refrigerant shortage amount of the first refrigerant insufficient state; the refrigerant state setting values correspond to the sufficient state, the first refrigerant insufficient state and the second refrigerant insufficient state, respectively.

2. The air conditioner control method according to claim 1, wherein: The frequency reduction control conditions include: a first frequency reduction control condition and a second frequency reduction control condition; If the compressor exhaust temperature meets the first frequency reduction control condition, the compressor is controlled to operate at a frequency reduction rate of a first set frequency reduction rate; if the compressor exhaust temperature meets the second frequency reduction control condition, the compressor is controlled to operate at a frequency reduction rate of a second set frequency reduction rate; the first set frequency reduction rate is less than the second set frequency reduction rate.

3. The air conditioner control method according to claim 2, wherein: During the frequency reduction control process, if the compressor exhaust temperature meets the first frequency protection condition, the compressor frequency is prohibited from decreasing; if the compressor exhaust temperature meets the second frequency protection condition, the compressor frequency is controlled to increase according to the first set frequency increase rate.

4. The air conditioner control method according to claim 2, wherein: The lower limit boundary thresholds of the maintenance control condition, the first frequency reduction control condition, the second frequency reduction control condition and the forced shutdown protection condition are increased in sequence; The exhaust temperature correction value is a negative value, and the boundary threshold after the control condition is corrected is the sum of the boundary threshold before the control condition is corrected and the exhaust temperature correction value.

5. An air conditioner control device, characterized in that: include: a sampling module configured to detect the compressor exhaust temperature during normal startup of the air conditioner; a first determination module configured to determine whether the compressor exhaust temperature satisfies any one of a maintenance control condition, a frequency reduction control condition, or a forced shutdown protection condition; a first execution module, configured to execute corresponding maintenance control, frequency reduction control or forced shutdown protection on the compressor when the exhaust temperature of the compressor meets any one of a maintenance control condition, a frequency reduction control condition or a forced shutdown protection condition; a recording module configured to record the number of frequency reduction controls executed and the number of protection controls executed for forced shutdown protection control; a second execution module configured to execute exhaust protection control when one of the frequency reduction control times and the protection control times meets an exhaust protection condition; a second determination module configured to determine whether the compressor exhaust temperature meets the frequency reduction control condition again when performing exhaust protection control; a calculation module configured to call the exhaust temperature correction value to correct the boundary threshold of the maintenance control condition each time the frequency reduction control condition is met again until the compressor operating frequency remains within the set range within a first set period, and calculate the sum of the exhaust temperature correction values; and A determination module, wherein the determination module is configured to compare the sum of the exhaust temperature correction values with a plurality of refrigerant state setting values to determine the current refrigerant state: when the sum of the exhaust temperature correction values is less than the first refrigerant state setting value, the current refrigerant state is determined to be a relatively sufficient state; when the sum of the exhaust temperature correction values is less than the second refrigerant state setting value and greater than the first refrigerant state setting value, the current refrigerant state is determined to be a first refrigerant insufficient state; when the sum of the exhaust temperature correction values is greater than the second refrigerant state setting value, the current refrigerant state is determined to be a second refrigerant insufficient state; wherein the refrigerant insufficient amount of the second refrigerant insufficient state is greater than the refrigerant insufficient amount of the first refrigerant insufficient state; the refrigerant state setting values correspond to the sufficient state, the first refrigerant insufficient state and the second refrigerant insufficient state, respectively.

6. The air conditioner control device according to claim 5, characterized in that: The frequency reduction control conditions include: a first frequency reduction control condition and a second frequency reduction control condition; The first execution module is configured to control the compressor to operate at a first set frequency reduction rate when the compressor exhaust temperature meets the first frequency reduction control condition; and control the compressor to operate at a second set frequency reduction rate when the compressor exhaust temperature meets the second frequency reduction control condition; The first set frequency reduction rate is less than the second set frequency reduction rate; the boundary thresholds of the maintenance control condition, the first frequency reduction control condition, the second frequency reduction control condition and the forced shutdown protection condition increase in sequence.

7. The air conditioner control device according to claim 6, characterized in that: During the frequency reduction control process, the first execution module is configured to prohibit the compressor frequency from decreasing when the compressor exhaust temperature meets the first frequency protection condition; and control the compressor frequency to increase according to the first set frequency increase rate when the compressor exhaust temperature meets the second frequency protection condition.

8. An air conditioner, characterized in that: Apply the air conditioner control method according to any one of claims 1 to 4.

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