Control method and system of heat pump air conditioning system, storage medium and program product

Abstract

The embodiment of the invention provides a control method and system of a heat pump air conditioning system, a storage medium and a program product. The method comprises the steps that when a control unit receives a heating operation instruction, a compressor is controlled to conduct heating, and the outdoor environment temperature of the compressor is obtained; when the outdoor environment temperature is smaller than or equal to a preset first temperature threshold value, the control unit controls the electromagnetic valve to be in an open state, so that a refrigerant compressed by the compressor heats the compressor and then returns to the compressor through the electromagnetic valve; the control unit controls the electromagnetic valve to be in a closed state when the outdoor environment temperature is larger than a first temperature threshold value. The opening and closing state of the electromagnetic valve is adjusted through the control unit according to the change of the outdoor environment temperature, so that part of high-temperature refrigerants are subjected to self-circulation through the electromagnetic valve to quickly heat the compressor, the heating power is large, and discharging of the refrigerants in the compressor is facilitated. And the problems of liquid impact, starting with liquid and oil shortage caused by too low temperature in a low-temperature environment are effectively prevented.

Description

Technical Field

[0001] The present application relates to the field of rail transit vehicles, and in particular to a control method, system, storage medium and program product of a heat pump air-conditioning system. Background Art

[0002] As the primary air conditioning device, heat pump air conditioning systems play a crucial role in controlling the ambient temperature and humidity inside rail transit vehicles and ensuring passenger comfort. They consist of a compressor, indoor and outdoor heat exchangers, a throttling device, and indoor and outdoor fans. They can switch between cooling and heating by switching the direction of the refrigerant flow through a four-way reversing valve.

[0003] During the winter heating season, the compressor temperature drops too low. When the compressor is shut down, its temperature is lower than that of the evaporator. The pressure differential between the compressor and evaporator forces liquid refrigerant to migrate into the compressor. Because the low temperature makes it easier for refrigerant to accumulate inside the compressor, excess liquid refrigerant quickly evaporates when the compressor starts, but it doesn't have enough time to completely vaporize, causing liquid shock. The lowered lubricating oil temperature absorbs refrigerant vapor from the oil surface, causing the oil sump pressure to drop below that of the evaporator, attracting vaporized refrigerant from the evaporator to gradually migrate into the compressor. During the next startup, this refrigerant causes the lubricant to foam, forming a foamy mixture that affects proper lubrication and startup of the compressor. This refrigerant migration and the potential for flooded startups cause the refrigerant to mix with the lubricant, diluting the lubricant. This not only reduces the lubricating oil's viscosity and lubrication effectiveness, but can also cause some of the lubricant to be discharged from the compressor along with the refrigerant, causing the compressor to starve.

[0004] After the vehicle is put into operation in winter, the air conditioning equipment needs to be started quickly to make the temperature inside the vehicle reach the set target temperature. However, the power of the compressor electric heating belt is too small. After the air conditioning unit is powered on, there is not enough time to heat the compressor. The refrigerant that migrates to the inside of the compressor cannot be effectively discharged, causing problems such as liquid shock, liquid start and oil shortage. Summary of the Invention

[0005] The embodiments of the present application provide a control method, system, storage medium and program product for a heat pump air conditioning system, which are used to increase the heating rate and accelerate the discharge of refrigerant inside the compressor, thereby avoiding problems such as liquid shock, liquid start-up and oil shortage after the compressor is started.

[0006] In a first aspect, an embodiment of the present application provides a method for controlling a heat pump air conditioning system, the heat pump air conditioning system comprising a compressor, a solenoid valve connected in parallel with the compressor, and a control unit communicatively connected to the compressor and the solenoid valve, the method comprising:

[0007] When receiving a heating operation instruction, the control unit controls the compressor to perform heating and obtains the outdoor ambient temperature of the compressor;

[0008] The control unit controls the solenoid valve to be in an open state when the outdoor ambient temperature is less than or equal to a preset first temperature threshold, so that the refrigerant compressed by the compressor heats the compressor and then returns to the compressor through the solenoid valve;

[0009] The control unit controls the solenoid valve to be in a closed state when the outdoor ambient temperature is greater than the first temperature threshold.

[0010] In a possible implementation, there are multiple compressors, each of which corresponds to a solenoid valve, and controlling the compressors to perform heating includes:

[0011] determining a first temperature difference between a set temperature and the outdoor ambient temperature, and determining a target number of compressors according to the first temperature difference, wherein the target number of compressors is positively correlated with the first temperature difference;

[0012] determining a first compressor of the target number of compressors from the plurality of compressors;

[0013] The first compressor is controlled to perform heating through the four-way valve of the first compressor, and the second compressor is controlled to be in a stopped state, where the second compressor is a compressor other than the first compressor.

[0014] In a possible implementation, controlling the solenoid valve to be in an open state includes:

[0015] controlling the solenoid valve corresponding to the first compressor to be in an open state;

[0016] The solenoid valve controlling the second compressor is in a closed state.

[0017] In a possible implementation, the method further includes:

[0018] After opening the solenoid valve, the control unit obtains the exhaust temperature and exhaust pressure of the compressor and determines the saturation temperature corresponding to the exhaust pressure;

[0019] The control unit calculates a second temperature difference between the exhaust temperature and the saturation temperature;

[0020] The control unit controls the solenoid valve to be in a closed state when the second temperature difference is greater than a preset second temperature threshold.

[0021] In one possible implementation, the method further includes:

[0022] When the second temperature difference is less than the second temperature threshold, the control unit controls the solenoid valve to be in an open state and returns to the step of obtaining the exhaust temperature and exhaust pressure of the compressor.

[0023] In a possible implementation, the method further includes:

[0024] When receiving a cooling operation instruction, the control unit operates the compressor and controls the solenoid valve to be in a closed state.

[0025] In a second aspect, an embodiment of the present application provides a heat pump air conditioning system, comprising a compressor, a solenoid valve connected in parallel with the compressor, and a control unit communicatively connected to the compressor and the solenoid valve, wherein the control unit is configured to:

[0026] When a heating operation instruction is received, controlling the compressor to perform heating and obtaining the outdoor ambient temperature of the compressor;

[0027] When the outdoor ambient temperature is less than or equal to a preset first temperature threshold, controlling the solenoid valve to be in an open state so that the refrigerant compressed by the compressor heats the compressor and then returns to the compressor through the solenoid valve;

[0028] When the outdoor ambient temperature is greater than the first temperature threshold, the solenoid valve is controlled to be in a closed state.

[0029] In a possible implementation manner, the control unit is specifically configured to:

[0030] determining a first temperature difference between a set temperature and the outdoor ambient temperature, and determining a target number of compressors according to the first temperature difference, wherein the target number of compressors is positively correlated with the first temperature difference;

[0031] determining a first compressor of the target number of compressors from the plurality of compressors;

[0032] The first compressor is controlled to perform heating through the four-way valve of the first compressor, and the second compressor is controlled to be in a stopped state, where the second compressor is a compressor other than the first compressor.

[0033] In a possible implementation manner, the control unit is specifically configured to:

[0034] controlling the solenoid valve corresponding to the first compressor to be in an open state;

[0035] The solenoid valve controlling the second compressor is in a closed state.

[0036] In a possible implementation manner, the control unit is further configured to:

[0037] After opening the solenoid valve, the control unit obtains the exhaust temperature and exhaust pressure of the compressor and determines the saturation temperature corresponding to the exhaust pressure;

[0038] The control unit calculates a second temperature difference between the exhaust temperature and the saturation temperature;

[0039] The control unit controls the solenoid valve to be in a closed state when the second temperature difference is greater than a preset second temperature threshold.

[0040] In a possible implementation manner, the control unit is further configured to:

[0041] When the second temperature difference is less than the second temperature threshold, the control unit controls the solenoid valve to be in an open state and returns to the step of obtaining the exhaust temperature and exhaust pressure of the compressor.

[0042] In a possible implementation manner, the control unit is further configured to:

[0043] When receiving a cooling operation instruction, the control unit operates the compressor and controls the solenoid valve to be in a closed state.

[0044] In a third aspect, an embodiment of the present application provides a control unit, including: a memory, a processor;

[0045] The memory stores computer-executable instructions;

[0046] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementations of the first aspect.

[0047] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the first aspect above and / or various possible implementation methods of the first aspect.

[0048] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above first aspect and / or various possible implementation methods of the first aspect.

[0049] The control method, system, storage medium and program product of the heat pump air conditioning system provided in the embodiment of the present application are as follows: when the control unit receives a heating operation instruction, it controls the compressor to perform heating and obtains the outdoor ambient temperature of the compressor; when the outdoor ambient temperature is less than or equal to a preset first temperature threshold, the control unit controls the solenoid valve to be in an open state, so that the refrigerant compressed by the compressor heats the compressor and then returns to the compressor through the solenoid valve; when the outdoor ambient temperature is greater than the first temperature threshold, the control unit controls the solenoid valve to be in a closed state. By intelligently adjusting the opening and closing state of the solenoid valve according to changes in the outdoor ambient temperature by the control unit, the protection of the compressor and the optimization of the heating efficiency of the heat pump air conditioning system are achieved. In a low temperature environment, the solenoid valve is opened to heat the compressor to prevent it from having problems such as liquid shock, liquid start-up and oil shortage due to too low temperature; when the temperature is suitably higher, the solenoid valve is closed to allow the system to heat normally. By automatically controlling the opening and closing of the solenoid valve, energy utilization efficiency and operational reliability are effectively improved, and the adverse effects of low temperature environment on the compressor are effectively avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0051] Figure 1 A schematic diagram of the structure of the heat pump air conditioning system provided in this application;

[0052] Figure 2 A flow chart of a control method for a heat pump air conditioning system provided in this application;

[0053] Figure 3 This is a schematic diagram of the structure of the control unit provided in this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] 10-compressor; 20-solenoid valve; 30-control unit; 40-four-way valve;

[0055] 101-first compressor; 102-second compressor; 103-indoor heat exchanger; 104-outdoor heat exchanger;

[0056] 201-first solenoid valve; 202-second solenoid valve;

[0057] 301 - processor; 302 - memory; 303 - communication component; 304 - bus.

[0058] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0059] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0060] When the compressor is stopped, its temperature is lower than that of the evaporator. The pressure difference between the two causes liquid refrigerant to migrate toward the compressor. In winter, the low temperatures make it more likely for refrigerant to accumulate inside the compressor. When the compressor starts, excess liquid refrigerant quickly evaporates before it can fully vaporize, causing liquid hammer.

[0061] When the compressor is shut down, the lubricating oil cools and absorbs refrigerant vapor from the oil surface, causing the oil sump pressure to drop below that of the evaporator. This attracts the vaporized refrigerant from the evaporator and gradually migrates into the compressor. Upon the next startup, this migrated refrigerant causes the lubricating oil to foam, forming a foamy mixture that can affect proper lubrication and startup of the compressor. If the air conditioning system is shut down for extended periods, refrigerant migration is exacerbated. The longer the downtime, the more refrigerant migrates into the lubricating oil, increasing the likelihood of flooded startup.

[0062] During the winter heating season, refrigerant migration and possible flooded startups cause the refrigerant to mix with the lubricant, diluting the lubricant. This not only reduces the lubricant's viscosity and lubrication effectiveness, but can also cause some of the lubricant to be discharged from the compressor along with the refrigerant, causing the compressor to run out of oil. In low winter temperatures, the lubricant's viscosity increases, impairing its fluidity, further exacerbating the problem of poor oil return.

[0063] In the existing technology, after a vehicle is put into operation in winter, the air-conditioning equipment needs to be started quickly to make the temperature inside the vehicle reach the set target temperature. However, the power of the compressor electric heating belt is too small, and the air-conditioning unit does not have enough time to heat the compressor after being powered on. The refrigerant that migrates to the inside of the compressor cannot be effectively discharged, causing problems such as liquid shock, liquid start-up and oil shortage after the compressor is started.

[0064] The control method of the heat pump air-conditioning system provided in the present application effectively reduces the occurrence of liquid shock, liquid start-up and oil shortage after the compressor is started by increasing the heating rate and accelerating the discharge of refrigerant inside the compressor.

[0065] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0066] Figure 1 A schematic diagram of the structure of the heat pump air conditioning system provided in this application; Figure 2 A flow chart of the control method of the heat pump air conditioning system provided in this application is shown as follows: Figure 1 、 Figure 2 As shown, the heat pump air conditioning system includes a compressor 10 , a solenoid valve 20 connected in parallel with the compressor 10 , and a control unit 30 communicatively connected to the compressor 10 and the solenoid valve 20 .

[0067] Specifically, Figure 1 The example uses a system circuit consisting of two compressors. The first system circuit includes compressor 101, four-way valve 40, outdoor heat exchanger 104, indoor heat exchanger 103, and solenoid valve 201; the second system circuit includes compressor 102, four-way valve 40, outdoor heat exchanger 104, indoor heat exchanger 103, and solenoid valve 202. Each system circuit switches between the cooling cycle and the heating cycle via four-way valve 40. When the ambient temperature is too low, compressor 10 will self-heat. By opening solenoid valve 20, some high-temperature refrigerant will self-circulate through solenoid valve 20, rapidly heating compressor 10. This high heating power and rapid heating speed effectively raise the temperature of compressor 10 while vaporizing the liquid refrigerant inside compressor 10 and discharging it from compressor 10. At the same time, the lubricating oil removed from compressor 10 by the vaporized refrigerant will be carried back into compressor 10 by the gaseous refrigerant, solving the problems of liquid shock, flooded start-up, and oil shortage that are often caused by low-temperature startup of compressor 10.

[0068] The control method of the heat pump air conditioning system specifically includes the following steps:

[0069] Step S1: upon receiving a heating operation instruction, the control unit controls the compressor to perform heating and obtains the outdoor ambient temperature of the compressor.

[0070] Specifically, when a user requires the heat pump air conditioning system to operate in heating mode, a heating operation instruction is sent to the system. The control unit is responsible for receiving and processing the instruction. After receiving the heating instruction, it sends a corresponding control signal to the compressor, driving the compressor to start operating in heating mode. At the same time, the control unit obtains real-time temperature information of the outdoor environment where the compressor is located through a connection with an external temperature sensor. This enables the heat pump air conditioning system to switch from standby or other operating states to heating mode, causing the compressor to start working to provide heat. By accurately understanding the temperature conditions of the outdoor environment, it provides a basis for subsequent control, ensuring that the system enters heating mode according to user needs and preparing for subsequent intelligent adjustment based on the outdoor ambient temperature.

[0071] The control unit can quickly respond to user needs and start the heating function in time. It can also obtain the outdoor ambient temperature in real time, perform precise control according to actual conditions, and improve energy utilization efficiency.

[0072] Step S2: When the outdoor ambient temperature is less than or equal to a preset first temperature threshold, the control unit controls the solenoid valve to be in an open state, so that the refrigerant compressed by the compressor heats the compressor and then returns to the compressor through the solenoid valve.

[0073] Specifically, when the outdoor ambient temperature is less than or equal to a first temperature threshold, the control unit determines that the compressor's operating environment is relatively cold, and the refrigerant temperature within the compressor is low, potentially causing compressor operational issues due to excessive cold. By sending a control signal to the solenoid valve, turning it open, the high-temperature, high-pressure refrigerant compressed by the compressor can flow back through the solenoid valve into the compressor, heating the compressor itself and raising the temperature within the compressor, thereby ensuring stable and efficient operation in low-temperature environments.

[0074] The system automatically adjusts the opening and closing of the solenoid valve based on the outdoor ambient temperature, enabling real-time adaptation to varying environmental conditions without manual intervention, enhancing the system's intelligence and operational reliability. Furthermore, heating protection for the compressor improves the heating efficiency and stability of the heat pump air conditioning system.

[0075] Step S3: When the outdoor ambient temperature is greater than a first temperature threshold, the control unit controls the solenoid valve to be in a closed state.

[0076] Specifically, when the outdoor ambient temperature exceeds a preset first temperature threshold, the ambient temperature of the compressor is relatively high, and the temperature of the refrigerant is also correspondingly high, so the operation of the compressor itself is not affected by the low temperature. The control unit sends a control signal to the solenoid valve to control the solenoid valve to be in a closed state, thereby cutting off the refrigerant from flowing back to the compressor.

[0077] The control method for a heat pump air conditioning system provided in an embodiment of the present invention uses a control unit to adjust the opening and closing state of a solenoid valve according to changes in the outdoor ambient temperature, allowing some high-temperature refrigerant to self-circulate through the solenoid valve to quickly heat the compressor. This method has high heating power, fast heating speed, and facilitates the discharge of refrigerant from the compressor. This method effectively prevents problems such as liquid shock, liquid start-up, and oil shortage caused by excessively low temperatures in low-temperature environments. When the temperature is suitably higher, the solenoid valve is closed to allow the system to heat normally. By controlling the on-off state of the solenoid valve, energy utilization efficiency and operational reliability are effectively improved, and the adverse effects of low-temperature environments on the compressor are effectively avoided.

[0078] In this embodiment, there are multiple compressors, and each compressor corresponds to a solenoid valve.

[0079] Specifically, in a heat pump air-conditioning system equipped with multiple compressors and each compressor corresponds to a solenoid valve, when a heating operation instruction is received, the control unit will monitor the outdoor ambient temperature of each compressor respectively. Figure 1 In the figure, only a circuit consisting of two compressors is used as an example. The number of compressors can be multiple, and each compressor corresponds to a solenoid valve.

[0080] Multiple compressors can operate independently and collaboratively based on their respective operating conditions. In heating scenarios with small temperature differences, only some compressors need to be activated to meet indoor heating needs. Compared to activating all compressors, this effectively reduces system energy consumption, achieving energy-saving operation and reducing energy consumption and operating costs.

[0081] In heating scenarios with small temperature differences, since not all compressors are running at full intensity all the time, wear and tear on the compressors is reduced, thereby extending their service life. This also reduces the potential for failures caused by excessive operation, improving the reliability and stability of the entire system.

[0082] The process of controlling the compressor to perform heating in the above embodiment is specifically implemented by the following steps:

[0083] Step a1: determining a first temperature difference between a set temperature and an outdoor ambient temperature, and determining a target number of compressors according to the first temperature difference, wherein the target number of compressors is positively correlated with the first temperature difference.

[0084] Specifically, the system can accurately determine the number of compressors required based on actual temperature requirements, avoiding the problem of too many compressors, which would lead to energy waste and excessive heating, or too few compressors, which would fail to meet indoor temperature requirements. Determining the target number of compressors based on temperature differences allows for quick and accurate adaptation to varying ambient temperature conditions, improving the system's flexibility and adaptability. Furthermore, determining the number of compressors based on actual demand helps improve energy efficiency and reduce unnecessary energy consumption.

[0085] Step a2: determining a first compressor of a target number of compressors from a plurality of compressors.

[0086] Specifically, the target number of compressors is determined by ranking them based on factors such as priority, performance, and age, and then selecting them in order. For example, compressors with good maintenance and stable performance may be prioritized, or compressors may be rotated to ensure uniform wear. This selection process can be accomplished by establishing a database or using a priority algorithm model.

[0087] Proper compressor selection can optimize the performance and lifespan of the entire system. For example, by avoiding excessive wear of certain compressors due to prolonged continuous operation, rotating compressors can distribute wear more evenly across the compressors, extending the lifespan of the entire compressor unit. Furthermore, carefully selected compressors can help improve system reliability and reduce the risk of system failures caused by compressor failures.

[0088] Step a3: Control the first compressor to perform heating through the four-way valve of the first compressor, and control the second compressor to be in a stopped state, where the second compressor is a compressor other than the first compressor.

[0089] Specifically, the second compressor is a compressor other than the first compressor, and the number can be one or more. The four-way valve can change the flow direction of the refrigerant, and the compressor can be placed in a heating cycle state by controlling the four-way valve. In heating mode, the four-way valve will cause the high-temperature and high-pressure refrigerant discharged from the compressor to flow to the indoor heat exchanger, thereby releasing heat into the room. In heating scenarios with small temperature differences, only some compressors need to be started to meet indoor heating needs. Compared with starting all compressors, starting only the first compressor effectively reduces the energy consumption of the system, achieves energy-saving operation, and reduces energy consumption and operating costs.

[0090] This embodiment describes in detail the process of controlling the solenoid valve to be in the open state in the above embodiment. The specific implementation of this process includes the following steps:

[0091] Step b1, controlling the solenoid valve corresponding to the first compressor to be in an open state.

[0092] Specifically, when the solenoid valve corresponding to the first compressor needs to be opened, the control system sends an electrical signal through the control circuit to the solenoid valve's coil, generating a magnetic field. Under the influence of this magnetic field, the valve core inside the solenoid valve is attracted and moves, thereby opening the channel, allowing the refrigerant to circulate through the solenoid valve and flow back into the first compressor. After entering the first compressor, the refrigerant is compressed in the compressor, causing its pressure and temperature to rise. Because the solenoid valve is in the open state, the refrigerant compressed by the compressor heats the compressor and then returns to the compressor through the solenoid valve, completing the self-circulating heating process.

[0093] Step b2: Control the solenoid valve of the second compressor to be in a closed state.

[0094] Specifically, the second compressor is a compressor other than the first compressor, and the number can be one or more. The second compressor is in a stopped state, and the solenoid valve of the second compressor is in a closed state, which reduces the number of compressor operations, effectively avoids energy waste, and reduces compressor losses.

[0095] By precisely controlling a single compressor, the present invention allows the system to better adapt to varying temperature environments. For example, in partial load conditions, only the first compressor can be operated, meeting heating requirements while reducing energy consumption. Furthermore, the solenoid valve's closing operation is simple and responsive, enabling timely adjustment based on actual conditions.

[0096] In some optional embodiments, the method further includes:

[0097] In step c1, after the solenoid valve is opened, the control unit obtains the exhaust temperature and exhaust pressure of the compressor and determines the saturation temperature corresponding to the exhaust pressure.

[0098] Specifically, after the solenoid valve is opened, the compressor starts working and the refrigerant is compressed for self-circulation heating. The control unit can obtain the exhaust temperature and exhaust pressure of the compressor through sensors. The exhaust temperature sensor usually uses a thermocouple or thermistor, which can accurately measure the exhaust temperature; the exhaust pressure is obtained through a pressure sensor.

[0099] When the gas composition and physical properties are known, the corresponding saturation temperature can be calculated based on the measured pressure. For example, for R410A refrigerant, the saturation temperature corresponding to the exhaust pressure can be accurately determined using existing pressure-temperature comparison tables. By acquiring the exhaust temperature, pressure, and saturation temperature of the compressor in real time, the operating status of the compressor and the refrigerant can be reflected, providing a data foundation for subsequent control.

[0100] In step c2, the control unit calculates a second temperature difference obtained by subtracting the saturation temperature from the exhaust temperature.

[0101] Specifically, the second temperature difference may reflect the degree of deviation between the compressor exhaust state and the ideal saturation state.

[0102] In step c3, the control unit controls the solenoid valve to be in a closed state when the second temperature difference is greater than a preset second temperature threshold.

[0103] Specifically, when the second temperature difference exceeds a preset second temperature threshold, the control unit issues a command to close the solenoid valve. The second temperature threshold is a value pre-set based on the compressor's performance, the refrigerant's properties, and operational requirements. When the second temperature difference exceeds the preset second temperature threshold, the solenoid valve closes, preventing further refrigerant from entering the compressor and ending the self-circulating heating process, thereby preventing further compressor overheating and effectively protecting the compressor.

[0104] In some optional embodiments, the method further includes:

[0105] When the second temperature difference is less than the second temperature threshold, the control unit controls the solenoid valve to be in an open state and returns to the step of obtaining the exhaust temperature and exhaust pressure of the compressor.

[0106] Specifically, the switching state of the solenoid valve is dynamically adjusted by real-time monitoring of the temperature difference to ensure that the compressor operates under appropriate temperature conditions. When the second temperature difference is less than the second temperature threshold, the solenoid valve is kept open, allowing the refrigerant to continue to enter the compressor for self-circulation heating, thereby increasing the operating temperature of the compressor. At the same time, by continuously returning to obtain the exhaust temperature and exhaust pressure, the control unit can grasp the operating status of the compressor in real time and promptly detect any possible abnormal conditions, such as sudden changes in temperature or pressure, so that appropriate measures can be taken quickly to make adjustments. This helps to improve the operating efficiency and stability of the entire system and reduce performance degradation or failures caused by unstable compressor operating conditions.

[0107] The working state of the compressor will also change. By continuously monitoring the exhaust temperature and pressure and adjusting the solenoid valve state according to the temperature difference, it can meet the thermal operating conditions. If the temperature is not high enough, it will increase the temperature through self-circulation heating. When the temperature meets the requirements, the self-circulation heating will be stopped. The heating efficiency is high and the speed is fast, which effectively avoids the problem of compressor failure caused by low temperature.

[0108] In some optional embodiments, the method further includes:

[0109] When the control unit receives the cooling operation instruction, it runs the compressor and controls the solenoid valve to be in the closed state.

[0110] Specifically, in cooling mode, a heat pump air conditioning system absorbs indoor heat and discharges it outdoors to lower the indoor temperature. The closed solenoid valve prevents refrigerant from flowing into unnecessary branches, concentrating heat exchange within the main circulation loop and ensuring cooling efficiency.

[0111] like Figure 1 As shown, the heat pump air conditioning system includes: a compressor 10, a solenoid valve 20 connected in parallel with the compressor 10, and a control unit 30 communicatively connected to the compressor 10 and the solenoid valve 20, the control unit 30 is used to:

[0112] When receiving a heating operation instruction, the compressor 10 is controlled to perform heating and the outdoor ambient temperature of the compressor 10 is obtained;

[0113] When the outdoor ambient temperature is less than or equal to a preset first temperature threshold, the solenoid valve 20 is controlled to be in an open state, so that the refrigerant compressed by the compressor 10 heats the compressor 10 and then returns to the compressor 10 through the solenoid valve 20;

[0114] When the outdoor ambient temperature is greater than the first temperature threshold, the solenoid valve 20 is controlled to be in a closed state.

[0115] In a possible implementation, the control unit 30 is specifically configured to:

[0116] Determine a first temperature difference between the set temperature and the outdoor ambient temperature, and determine a target number of compressors 10 according to the first temperature difference, wherein the target number of compressors 10 is positively correlated with the first temperature difference;

[0117] A first compressor 101 that determines a target number of compressors 10 from among the plurality of compressors 10;

[0118] The four-way valve 40 of the first compressor 101 controls the first compressor 101 to perform heating, and controls the second compressor 102 to be in a stopped state. The second compressor 102 is a compressor 10 other than the first compressor 101 .

[0119] In a possible implementation, the control unit 30 is specifically configured to:

[0120] Control the solenoid valve corresponding to the first compressor 101 to be in an open state;

[0121] The solenoid valve controlling the second compressor 102 is in a closed state.

[0122] In a possible implementation, the control unit 30 is further configured to:

[0123] After opening the solenoid valve, the control unit 30 obtains the exhaust temperature and exhaust pressure of the compressor 10 and determines the saturation temperature corresponding to the exhaust pressure;

[0124] The control unit 30 calculates a second temperature difference of the exhaust gas temperature minus the saturation temperature;

[0125] The control unit 30 controls the solenoid valve to be in a closed state when the second temperature difference is greater than a preset second temperature threshold.

[0126] In a possible implementation, the control unit 30 is further configured to:

[0127] When the second temperature difference is less than the second temperature threshold, the control unit 30 controls the solenoid valve to be in an open state and returns to the step of obtaining the exhaust temperature and exhaust pressure of the compressor 10 .

[0128] In a possible implementation, the control unit 30 is further configured to:

[0129] When receiving the cooling operation instruction, the control unit 30 operates the compressor 10 and controls the solenoid valve to be in a closed state.

[0130] The heat pump air conditioning system provided in this embodiment can be used to execute the control method of the heat pump air conditioning system described above. Its implementation principle and technical effects are similar and will not be described in detail in this embodiment.

[0131] Figure 3 The schematic diagram of the control unit provided in this application is as follows: Figure 3 As shown, the control unit 30 includes: at least one processor 301 and a memory 302. Optionally, the control unit 30 also includes a communication component 303. The processor 301, the memory 302 and the communication component 303 are connected via a bus 304.

[0132] In a specific implementation process, at least one processor 301 executes the computer-executable instructions stored in the memory 302, so that the at least one processor 301 performs the above method.

[0133] The specific implementation process of the processor 301 can be found in the above method embodiment. Its implementation principle and technical effects are similar and will not be repeated here in this embodiment.

[0134] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASICs), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly executed by a hardware processor or by a combination of hardware and software modules within the processor.

[0135] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage.

[0136] A bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be categorized as address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0137] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0138] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0139] The readable storage medium may be implemented by any type of volatile or non-volatile memory device, or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0140] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0141] The division of units is merely a logical functional division; actual implementations may employ alternative divisions, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, any direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units, either through an interface, electrical, mechanical, or other means.

[0142] Units described as separate components may or may not be physically separate, and 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 these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0143] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0144] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the method of the present invention. The aforementioned storage medium includes various media that can store program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0145] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0146] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A control method for a heat pump air conditioning system, characterized in that: The heat pump air conditioning system includes a compressor, a solenoid valve connected in parallel with the compressor, and a control unit communicatively connected to the compressor and the solenoid valve. The method includes: When receiving a heating operation instruction, the control unit controls the compressor to perform heating and obtains the outdoor ambient temperature of the compressor; The control unit controls the solenoid valve to be in an open state when the outdoor ambient temperature is less than or equal to a preset first temperature threshold, so that the refrigerant compressed by the compressor heats the compressor and then returns to the compressor through the solenoid valve; The control unit controls the solenoid valve to be in a closed state when the outdoor ambient temperature is greater than the first temperature threshold.

2. The method according to claim 1, characterized in that There are multiple compressors, each of which corresponds to a solenoid valve, and controlling the compressors to perform heating includes: determining a first temperature difference between a set temperature and the outdoor ambient temperature, and determining a target number of compressors according to the first temperature difference, wherein the target number of compressors is positively correlated with the first temperature difference; determining a first compressor of the target number of compressors from the plurality of compressors; The first compressor is controlled to perform heating through the four-way valve of the first compressor, and the second compressor is controlled to be in a stopped state, where the second compressor is a compressor other than the first compressor.

3. The method according to claim 2, characterized in that The controlling the solenoid valve to be in an open state includes: controlling the solenoid valve corresponding to the first compressor to be in an open state; The solenoid valve controlling the second compressor is in a closed state.

4. The method according to any one of claims 1 to 3, characterized in that Also includes: After opening the solenoid valve, the control unit obtains the exhaust temperature and exhaust pressure of the compressor and determines the saturation temperature corresponding to the exhaust pressure; The control unit calculates a second temperature difference between the exhaust temperature and the saturation temperature; The control unit controls the solenoid valve to be in a closed state when the second temperature difference is greater than a preset second temperature threshold.

5. The method according to claim 4, characterized in that The method further comprises: When the second temperature difference is less than the second temperature threshold, the control unit controls the solenoid valve to be in an open state and returns to the step of obtaining the exhaust temperature and exhaust pressure of the compressor.

6. The method according to any one of claims 1 to 3, characterized in that Also includes: When receiving a cooling operation instruction, the control unit operates the compressor and controls the solenoid valve to be in a closed state.

7. A heat pump air conditioning system, characterized in that: The invention comprises a compressor, a solenoid valve connected in parallel with the compressor, and a control unit communicatively connected to the compressor and the solenoid valve, wherein the control unit is configured to: When a heating operation instruction is received, controlling the compressor to perform heating and obtaining the outdoor ambient temperature of the compressor; When the outdoor ambient temperature is less than or equal to a preset first temperature threshold, controlling the solenoid valve to be in an open state so that the refrigerant compressed by the compressor heats the compressor and then returns to the compressor through the solenoid valve; When the outdoor ambient temperature is greater than the first temperature threshold, the solenoid valve is controlled to be in a closed state.

8. A control unit, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 6 when executed by a processor.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 6 when the computer program is executed by a processor.

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