Control method and device for auxiliary expansion valve and heat pump

Abstract

The invention discloses a control method and device for an auxiliary expansion valve and a heat pump, and belongs to the technical field of heat pump systems. According to the technical scheme, under the condition that the enhanced vapor injection heat pump system starts the enhanced vapor injection function, whether the outlet water temperature of the target radiator is larger than or equal to the outlet water temperature threshold value or not is judged. When the outlet water temperature is larger than or equal to the outlet water temperature threshold value, it shows that the outlet water temperature is high, whether the exhaust temperature of the compressor is larger than or equal to the reference exhaust temperature or not is determined, and that is, whether the exhaust temperature of the compressor is high or not is judged. Under the condition that the exhaust temperature of the compressor is high, the auxiliary path expansion valve is closed to stop circulation of the refrigerant in the auxiliary loop, and the exhaust temperature of the compressor is prevented from rising rapidly, so that the probability of frequency reduction of the compressor and triggering of exhaust temperature protection is reduced, and the stability of the enhanced vapor injection heat pump system can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of heat pump systems, and in particular to a control method and device for an auxiliary expansion valve and a heat pump. Background Art

[0002] Under low ambient temperature conditions, the jet enthalpy heat pump system will increase the low-temperature heating capacity by jet enthalpy in the auxiliary circuit, that is, by opening the auxiliary circuit expansion valve.

[0003] As the auxiliary expansion valve is opened and the opening degree increases, the refrigerant has a high degree of superheat after heat exchange. When it returns to the compressor of the jet regenerative heat pump system, it is easy to cause the compressor exhaust temperature to rise rapidly, thereby triggering frequency reduction or exhaust temperature protection, which is not conducive to the stable operation of the jet regenerative heat pump system.

[0004] Therefore, how to improve the stability of the jet enthalpy heat pump system is a hot topic of research. Summary of the invention

[0005] The embodiment of the present application provides a control method, device and heat pump for an auxiliary expansion valve, which can improve the stability of an injection enthalpy heat pump system. The technical solution is as follows:

[0006] In one aspect, a method for controlling an auxiliary expansion valve is provided, the method comprising:

[0007] When the auxiliary expansion valve of the jet enthalpy heat pump system is opened, obtaining the outlet water temperature of the target heat exchanger of the jet enthalpy heat pump system, wherein the target heat exchanger is used to change the temperature of the water flowing through the target heat exchanger;

[0008] In the case where the outlet water temperature is greater than or equal to the outlet water temperature threshold, determining whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to a reference exhaust temperature, and the reference exhaust temperature is less than an exhaust protection temperature of the compressor;

[0009] When the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, the auxiliary expansion valve is controlled to be closed.

[0010] In one aspect, a control device for an auxiliary expansion valve is provided, the device comprising:

[0011] An acquisition module, used for acquiring the outlet water temperature of a target heat exchanger of the jet enthalpy heat pump system when the auxiliary expansion valve of the jet enthalpy heat pump system is opened, wherein the target heat exchanger is used for changing the temperature of water flowing through the target heat exchanger;

[0012] a determination module, configured to determine, when the outlet water temperature is greater than or equal to an outlet water temperature threshold, whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to a reference exhaust temperature, and the reference exhaust temperature is less than an exhaust protection temperature of the compressor;

[0013] The control module is used to control the auxiliary expansion valve to close when the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature.

[0014] In a possible implementation, the determination module is used to determine whether the exhaust temperature of the compressor tends to be stable when the outlet water temperature is greater than or equal to the outlet water temperature threshold; when the exhaust temperature of the compressor tends to be stable, determine whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to a reference exhaust temperature; when the exhaust temperature of the compressor does not tend to be stable, wait for the exhaust temperature of the compressor to stabilize before determining whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature.

[0015] In a possible implementation, the determination module is used to control the auxiliary expansion valve to open to a first opening at a first rate when the outlet water temperature is greater than or equal to the outlet water temperature threshold, and the first opening is the opening when the auxiliary expansion valve is fully opened; in the process of the auxiliary expansion valve opening at the first rate, obtain the first refrigerant temperature of the refrigerant in the auxiliary circuit before the economizer of the jet enthalpy heat pump system completes the heat exchange and the second refrigerant temperature after the economizer completes the heat exchange; when the difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold, control the auxiliary expansion valve to close to a second opening at a second rate, and the second opening is one tenth of the first opening; after a preset period of time, determine whether the exhaust temperature of the compressor tends to stabilize.

[0016] In a possible implementation manner, the control module is further configured to control the auxiliary circuit expansion valve to continue operating at a current opening when a difference between the second refrigerant temperature and the first refrigerant temperature is greater than the refrigerant temperature threshold.

[0017] In a possible implementation, the determination module is used to obtain N exhaust temperatures of the compressor, where the N exhaust temperatures are continuously collected exhaust temperatures and N is a positive integer; determine the average exhaust temperature of the first N-1 exhaust temperatures among the N exhaust temperatures; determine that the exhaust temperature of the compressor tends to be stable when the difference between the Nth exhaust temperature among the N exhaust temperatures and the average exhaust temperature is within a preset temperature range; determine that the exhaust temperature of the compressor does not tend to be stable when the difference between the Nth exhaust temperature among the N exhaust temperatures and the average exhaust temperature is not within the preset temperature range.

[0018] In a possible implementation manner, the control module is further configured to control the opening of the auxiliary expansion valve to increase a third opening when the exhaust temperature of the compressor is lower than the reference exhaust temperature.

[0019] In a possible implementation manner, the determination module is further used to re-determine whether the exhaust temperature of the compressor of the injection enthalpy heat pump system is greater than or equal to a reference exhaust temperature;

[0020] The control module is also used to control the auxiliary expansion valve to continue operating at the current opening when the re-determined exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature; to obtain the first refrigerant temperature of the refrigerant in the auxiliary circuit before the economizer of the jet enthalpy heat pump system completes heat exchange and the second refrigerant temperature after the economizer completes heat exchange when the re-determined exhaust temperature of the compressor is less than the reference exhaust temperature; and to control the auxiliary expansion valve based on the difference between the first refrigerant temperature and the second refrigerant temperature.

[0021] In a possible implementation, the control module is also used to control the auxiliary circuit expansion valve to continue operating at the current opening when the difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold; and to control the opening of the auxiliary circuit expansion valve to further increase the third opening when the difference between the second refrigerant temperature and the first refrigerant temperature is greater than the refrigerant temperature threshold.

[0022] In a possible implementation, the determination module is also used to determine whether the exhaust temperature of the compressor tends to be stable; when the exhaust temperature of the compressor tends to be stable, re-determine whether the exhaust temperature of the compressor of the jet regenerative heat pump system is greater than or equal to a reference exhaust temperature; when the exhaust temperature of the compressor does not tend to be stable, wait until the exhaust temperature of the compressor tends to be stable and then re-determine whether the exhaust temperature of the compressor of the jet regenerative heat pump system is greater than or equal to the reference exhaust temperature.

[0023] On the one hand, a heat pump is provided, which includes a control chip, the control chip includes one or more processors and one or more memories, at least one computer program is stored in the one or more memories, and the computer program is loaded and executed by the one or more processors to implement the control method of the auxiliary expansion valve.

[0024] On the one hand, a computer-readable storage medium is provided, in which at least one computer program is stored. The computer program is loaded and executed by a processor to implement the control method of the auxiliary expansion valve.

[0025] On the one hand, a computer program product or a computer program is provided, which includes a program code, and the program code is stored in a computer-readable storage medium. The processor of the control chip reads the program code from the computer-readable storage medium, and the processor executes the program code, so that the control chip executes the above-mentioned control method of the auxiliary expansion valve.

[0026] Through the technical solution provided in the embodiment of the present application, when the jet enthalpy increase function is turned on in the jet enthalpy increase heat pump system, it is determined whether the outlet water temperature of the target radiator is greater than or equal to the outlet water temperature threshold. When the outlet water temperature is greater than or equal to the outlet water temperature threshold, it means that the outlet water temperature is high, and it is determined whether the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, that is, whether the exhaust temperature of the compressor is high. When the exhaust temperature of the compressor is high, the auxiliary expansion valve is closed to terminate the circulation of the refrigerant in the auxiliary circuit to prevent the exhaust temperature of the compressor from rising rapidly, thereby reducing the probability of the compressor reducing frequency and triggering the exhaust temperature protection, and thus improving the stability of the jet enthalpy increase heat pump system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a schematic diagram of an implementation environment of a control method for an auxiliary circuit expansion valve provided in an embodiment of the present application;

[0029] Figure 2 This is a flow chart of a control method of an auxiliary circuit expansion valve provided in an embodiment of the present application;

[0030] Figure 3 is a flow chart of another control method of an auxiliary circuit expansion valve provided in an embodiment of the present application;

[0031] Figure 4 This is a flow chart of another method for controlling an auxiliary expansion valve provided in an embodiment of the present application;

[0032] Figure 5 It is a structural schematic diagram of a control device for an auxiliary circuit expansion valve provided in an embodiment of the present application;

[0033] Figure 6 It is a schematic diagram of the structure of a heat pump provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0035] In this application, the terms "first", "second", etc. are used to distinguish identical or similar items with basically the same effects and functions. It should be understood that there is no logical or temporal dependency between "first", "second", and "nth", nor is there any limitation on quantity and execution order.

[0036] In order to illustrate the technical solution provided by the embodiments of the present application, some terms involved in the embodiments of the present application are introduced below.

[0037] Heat pump system: The heat pump system is an efficient and environmentally friendly heat energy supply solution. It transfers heat energy from low-temperature heat sources to high-temperature heat sources by consuming a small amount of electricity to achieve functions such as heating, cooling or hot water supply. The working principle of the heat pump system is based on the reverse Carnot cycle and is mainly composed of components such as compressors, evaporators, condensers and expansion valves.

[0038] Jet enthalpy technology: Jet enthalpy technology is an innovative refrigerant cycle optimization method that aims to solve the problem of air source heat pump performance degradation in low temperature environments. Its core principle is to introduce intermediate air supplementation in the compressor to improve the heating capacity and efficiency of the system through additional refrigerant injection. This method cleverly achieves the decomposition of the compression ratio, reduces the pressure ratio of each compressor stage, thereby improving the volumetric efficiency and effectively controlling the exhaust temperature.

[0039] Compressor: A compressor is a driven fluid machine that boosts low-pressure gas to high-pressure gas. It is regarded as the heart of the heat pump system. Its actual responsibility is to increase the pressure and raise the suction pressure state to the exhaust pressure state.

[0040] Expansion valve: The expansion valve is an important component in the refrigeration system. It mainly plays the role of throttling, reducing pressure and regulating flow. It also has the function of preventing wet compression and liquid hammer to protect the compressor and abnormal overheating.

[0041] Refrigerant: A substance that transfers heat through evaporation and condensation in a heat pump system. It is a substance that easily absorbs heat and turns into gas, and easily releases heat and turns into water.

[0042] Economizer: A heat exchanger widely used in heat pump systems. Its main function is to absorb heat through the throttling evaporation process of the refrigerant itself, thereby supercooling another part of the refrigerant and improving the efficiency of the heat pump system.

[0043] Evaporator: The evaporator of a heat pump system works on the principle of heat exchange. In a heat pump system, when the refrigerant flows through the evaporator, its temperature rises and evaporates, thereby absorbing heat from the surrounding air.

[0044] After introducing the technical solution provided by the embodiment of the present application, the implementation environment of the technical solution provided by the embodiment of the present application is introduced below. Figure 1 The jet enthalpy heat pump system 100 of the embodiment of the present application includes a compressor 101, an economizer 102, an auxiliary expansion valve 103, a main expansion valve 104, a target heat exchanger 105 and an outdoor heat exchanger 106.

[0045] The compressor 101 is connected to the target heat exchanger 105 through a four-way valve, the target heat exchanger 105 is connected to the economizer 102, the economizer 102 is connected to the auxiliary expansion valve 103 and the main expansion valve 104 respectively, so as to divide the circuit into a main circuit and an auxiliary circuit. The main expansion valve 104 is connected to the outdoor heat exchanger 106, and the outdoor heat exchanger 106 is connected to the compressor through a four-way valve.

[0046] The compressor 101 includes two air intakes and one air exhaust port, wherein the two air intakes include a main air intake and an auxiliary air intake, and the main air intake is responsible for inhaling low-temperature and low-pressure refrigerant vapor from the evaporator. The auxiliary air intake is used to receive specially treated medium-pressure refrigerant vapor. When the jet enthalpy heat pump system turns on the jet enthalpy, the working process of the compressor 101 includes the following key steps. 1. Primary compression: The compressor inhales low-temperature and low-pressure refrigerant vapor from the main air intake and starts to perform preliminary compression on it. 2. Intermediate injection: At a certain moment in the compression process, the medium-pressure refrigerant vapor from the auxiliary air intake is injected into the compression chamber. 3. Mixed compression: The injected medium-pressure refrigerant vapor is fully mixed with the refrigerant vapor undergoing primary compression to form a new mixture. 4. Secondary compression: The mixed refrigerant vapor continues to be compressed to a high-pressure state and is finally discharged from the compressor. This design decomposes the original one-stage compression process of the compressor 101 into two stages, effectively reducing the pressure ratio of each compression, thereby improving the overall energy efficiency of the jet enthalpy heat pump system 100 and significantly enhancing the heating capacity in a low-temperature environment.

[0047] The economizer 102 plays a vital role in the jet enthalpy heat pump system 100. Its main function is to promote the heat exchange of the refrigerant between the main circuit and the auxiliary circuit, so as to realize the efficient operation of the enthalpy heat pump system 100. The working principle of the economizer is based on the phase change characteristics of the refrigerant. It realizes the mutual conversion of the refrigerant at different pressures and temperatures through the heat exchange process. Specifically, the working process of the economizer includes the following key steps: 1. Supercooling of the main circuit refrigerant: The high-pressure refrigerant water from the condenser is divided into two paths, one of which enters the main circuit of the economizer. Here, it exchanges heat with the low-pressure refrigerant in the auxiliary circuit to further reduce the temperature and achieve the supercooling effect. 2. Evaporation of the auxiliary circuit refrigerant: The other refrigerant enters the auxiliary circuit and becomes a low-pressure gas-liquid mixture after being reduced in pressure by the expansion valve. These mixtures come into contact with the refrigerant in the main circuit in the economizer, absorb heat and evaporate into gas. 3. Refrigerant separation: Inside the economizer, the evaporated gas is guided to the auxiliary air intake of the compressor 101, and the unevaporated water returns to the main circuit. 4. Refrigerant circulation: The evaporated gas directly enters the auxiliary air intake port of the compressor 101, and is compressed together with the refrigerant in the main circuit. This increases the air intake volume of the compressor 101, reduces the exhaust temperature of the compressor 101, and improves the overall efficiency of the jet enthalpy heat pump system 100.

[0048] The four-way valve is used to connect the refrigerant circuit. The S end and C end of the four-way valve are connected, and the E end and D end are connected.

[0049] The auxiliary circuit expansion valve 103 is used to adjust the flow rate of the refrigerant in the auxiliary cycle. The main circuit expansion valve 104 is used to adjust the flow rate of the refrigerant in the main circuit.

[0050] The target heat exchanger 105 is a heat exchanger for heating water, which can transfer the heat of the refrigerant to the water, and is also called an indoor condenser or water module. The water heated by the target heat exchanger 105 can be supplied to other facilities such as floor heating. In some embodiments, the target heat exchanger 105 is a shell and tube heat exchanger.

[0051] The outdoor heat exchanger 106 is used to absorb heat from the air, and is also called an outdoor evaporator. In some embodiments, the outdoor heat exchanger 106 is a fin heat exchanger.

[0052] The main circuit and the auxiliary circuit in the embodiment of the present application are explained below by taking the heating process and the refrigerant flow direction as an example.

[0053] The refrigerant flows out of the compressor and enters the D end of the four-way valve, and flows out from the E end of the four-way valve. The refrigerant enters the target heat exchanger 105, and flows out from the target heat exchanger 105 and enters the first passage of the economizer 102 ( Figure 1The refrigerant flows out of the first passage and passes through the main expansion valve 104, the outdoor heat exchanger 106, the C end of the four-way valve and the S end of the four-way valve, and finally returns to the compressor 101. The circuit through which the refrigerant passes is the main circuit.

[0054] After flowing out of the compressor, the refrigerant enters the D end of the four-way valve and flows out from the E end of the four-way valve. The refrigerant enters the target heat exchanger 105, flows out of the target heat exchanger 105 and enters the first passage of the economizer 102. After flowing out of the first passage, it flows through the auxiliary expansion valve 103 and enters the economizer 102 again. At this time, the refrigerant enters the second passage of the economizer 102 ( Figure 1 The refrigerant returns to the compressor 101 through the second passage, and the circuit through which the refrigerant passes is an auxiliary circuit.

[0055] Combination Figure 1 It can be seen that when the auxiliary expansion valve 103 is opened, the refrigerant flowing out of the first passage of the economizer 102 is divided into two parts, one part passes through the auxiliary expansion valve 103, and the other part passes through the main expansion valve 104, wherein the refrigerant passing through the auxiliary expansion valve 103 circulates in the auxiliary circuit, and the refrigerant passing through the main expansion valve 104 circulates in the main circuit.

[0056] The cooling process is the same as the heating process, except that the flow direction of the refrigerant is opposite, so it will not be described here.

[0057] After introducing the implementation environment of the embodiments of the present application, the application scenarios of the embodiments of the present application will be described below.

[0058] The control method of the auxiliary expansion valve provided in the embodiment of the present application can be applied to any jet reheat heat pump system. By adopting the technical solution provided in the embodiment of the present application, the auxiliary expansion valve can be controlled according to the exhaust temperature of the compressor, thereby improving the stability of the jet reheat heat pump system.

[0059] After introducing the implementation environment and application scenarios of the embodiment of the present application, the control method of the auxiliary expansion valve provided by the embodiment of the present application is described below. Figure 2 Taking the control chip of the jet enthalpy heat pump system as an example, the method includes the following steps.

[0060] 201. When the auxiliary expansion valve of the jet enthalpy heat pump system is opened, the control chip obtains the outlet water temperature of the target heat exchanger of the jet enthalpy heat pump system, and the target heat exchanger is used to change the temperature of the water flowing through.

[0061] Among them, the opening of the auxiliary expansion valve also means that the jet reheat function is turned on, and the refrigerant circulates in the main circuit and the auxiliary circuit (also called the auxiliary circuit). The auxiliary expansion valve refers to the expansion valve located on the auxiliary circuit, which can control the flow of the refrigerant in the auxiliary circuit. Correspondingly, the jet reheat heat pump system also includes a main expansion valve, which can control the flow of the refrigerant in the main circuit. The target heat exchanger includes a water inlet and a water outlet. Water enters the target heat exchanger through the water inlet and flows out of the target heat exchanger through the water outlet. The outlet water temperature refers to the water temperature measured at the water outlet. In addition, there is a refrigerant circulation pipeline in the target heat exchanger, so as to realize the heat exchange between the refrigerant and the flowing water. The refrigerant circulation pipeline is in contact with the water circulation pipeline and is not connected. In the heating scenario, the refrigerant absorbs heat from the outside, and the heat of the refrigerant can be transferred to the flowing water through the target heat exchanger, thereby realizing the heating of the flowing water. In the cooling scenario, the refrigerant absorbs heat from the water flowing through it, and the heat of the refrigerant can be transferred to the outside through the target heat exchanger, thereby cooling the water flowing through it.

[0062] 202. When the outlet water temperature is greater than or equal to the outlet water temperature threshold, the control chip determines whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to a reference exhaust temperature, and the reference exhaust temperature is less than the exhaust protection temperature of the compressor.

[0063] Among them, the outlet water temperature is greater than or equal to the outlet water temperature threshold, which means that the outlet water temperature is relatively high, the energy transferred from the refrigerant to the water is relatively limited, and the temperature of the refrigerant after passing through the target heat exchanger may be relatively high. The exhaust temperature of the compressor is the temperature of the refrigerant after the compressor compresses the refrigerant. The reference exhaust temperature is equivalent to an exhaust temperature limit. After the exhaust temperature exceeds the reference exhaust temperature, the compressor may experience frequency reduction and exhaust temperature protection, thereby affecting the stability of the jet enthalpy heat pump system. The exhaust protection temperature of the compressor can be regarded as the upper limit of the exhaust temperature of the compressor. When the exhaust temperature reaches or exceeds the exhaust protection temperature, the compressor will trigger the exhaust temperature protection, that is, the compressor will stop working to prevent damage. The exhaust protection temperature is associated with the model of the compressor, and the embodiments of the present application are not limited to this.

[0064] 203. When the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, the control chip controls the auxiliary expansion valve to close.

[0065] Among them, the exhaust temperature is greater than or equal to the reference exhaust temperature, which means that the exhaust temperature is high. When the auxiliary expansion valve is opened, it means that the jet reheat function is turned on. The refrigerant in the auxiliary circuit will enter the compressor, making the compressor's one compression process become a two-compression process, increasing the compression ratio of the refrigerant, and thus increasing the temperature of the refrigerant after compression. If the exhaust temperature of the compressor is high, close the auxiliary expansion valve to turn off the jet reheat function, and the refrigerant cannot circulate in the auxiliary circuit, preventing the compressor exhaust temperature from rising rapidly, thereby reducing the probability of the compressor reducing frequency and triggering the exhaust temperature protection.

[0066] Through the technical solution provided in the embodiment of the present application, when the jet enthalpy increase function is turned on in the jet enthalpy increase heat pump system, it is determined whether the outlet water temperature of the target radiator is greater than or equal to the outlet water temperature threshold. When the outlet water temperature is greater than or equal to the outlet water temperature threshold, it means that the outlet water temperature is high, and it is determined whether the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, that is, whether the exhaust temperature of the compressor is high. When the exhaust temperature of the compressor is high, the auxiliary expansion valve is closed to terminate the circulation of the refrigerant in the auxiliary circuit to prevent the exhaust temperature of the compressor from rising rapidly, thereby reducing the probability of the compressor reducing frequency and triggering the exhaust temperature protection, and thus improving the stability of the jet enthalpy increase heat pump system.

[0067] The above steps 201-203 are a brief introduction to the control method of the auxiliary expansion valve provided in the embodiment of the present application. The following will combine some examples to more clearly illustrate the technical solution provided in the embodiment of the present application. Figure 3 Taking the execution subject as a control chip as an example, the method includes the following steps.

[0068] 301. When the jet enthalpy heat pump system is running, the control chip determines whether to open the auxiliary expansion valve.

[0069] Among them, determining whether to turn on the auxiliary circuit expansion is to determine whether to turn on the jet reheat function. When the jet reheat function is turned on, the refrigerant can circulate in the main circuit and the auxiliary circuit; when the jet reheat function is not turned on, the refrigerant circulates in the main circuit. The auxiliary circuit expansion valve refers to an expansion valve located on the auxiliary circuit, which can control the flow of the refrigerant in the auxiliary circuit. Accordingly, the jet reheat heat pump system also includes a main circuit expansion valve, which can control the flow of the refrigerant in the main circuit. The exhaust temperature of the compressor is the temperature of the refrigerant after the compressor compresses the refrigerant. In the embodiment of the present application, the main circuit expansion valve and the auxiliary circuit expansion valve are both electronic expansion valves.

[0070] In a possible implementation, when the jet enthalpy heat pump system is running, the control chip obtains at least one of the external ambient temperature, the exhaust temperature of the compressor, and the heating demand parameter. The control chip determines whether to open the auxiliary expansion valve based on at least one of the external ambient temperature, the exhaust temperature of the compressor, and the heating demand parameter.

[0071] The external ambient temperature is the ambient temperature of the environment in which the evaporator of the jet enthalpy heat pump system is located outdoors, and the heating demand parameter is used to reflect the demand for the heating capacity of the jet enthalpy heat pump system. In some embodiments, the heating demand parameter includes the heating demand power.

[0072] In this embodiment, when the jet regenerative heat pump system is running, the external ambient temperature, the exhaust temperature of the compressor and at least one of the heating demand parameters are used to determine whether to open the auxiliary expansion valve. That is, the environment or demand is combined to determine whether to open the auxiliary expansion valve. The result of the judgment is more consistent with the environment or demand and has a higher accuracy.

[0073] For example, when the jet enthalpy heat pump system is running, the control chip obtains at least one of the external ambient temperature, the exhaust temperature of the compressor, and the heating demand parameter. When the external ambient temperature is less than or equal to the ambient temperature threshold, or the exhaust temperature is greater than or equal to the exhaust temperature threshold, or the heating demand is greater than or equal to the heating demand parameter threshold (for example, the heating demand power is greater than or equal to the heating demand power threshold), the control chip determines to open the auxiliary expansion valve. Accordingly, when the external ambient temperature is greater than the ambient temperature threshold, or the exhaust temperature is less than the exhaust temperature threshold, or the heating demand is less than the heating demand parameter threshold (for example, the heating demand power is less than the heating demand power threshold), the control chip determines not to open the auxiliary expansion valve.

[0074] Among them, the ambient temperature threshold, exhaust temperature threshold and heating demand parameter threshold are set by technical personnel according to actual conditions, and the embodiments of the present application do not limit this.

[0075] 302. When the auxiliary expansion valve of the jet enthalpy heat pump system is opened, the control chip obtains the outlet water temperature of the target heat exchanger of the jet enthalpy heat pump system, and the target heat exchanger is used to change the temperature of the water flowing through the target heat exchanger.

[0076] Among them, the opening of the auxiliary expansion valve also means that the jet enthalpy increase function is turned on, and the refrigerant circulates in the main circuit and the auxiliary circuit (also referred to as the auxiliary circuit). The target heat exchanger includes a water inlet and a water outlet. Water enters the target heat exchanger through the water inlet and flows out of the target heat exchanger through the water outlet. The outlet water temperature refers to the water temperature measured at the outlet. There is also a refrigerant circulation pipeline in the target heat exchanger to achieve heat exchange between the refrigerant and the water flowing through. The refrigerant circulation pipeline is in contact with the water circulation pipeline and does not penetrate. In some embodiments, the target heat exchanger is a shell and tube heat exchanger. Changing the temperature of the water flowing through includes increasing the temperature of the water flowing through and lowering the temperature of the water flowing through. In the heating scenario, the refrigerant absorbs heat from the outside world, and the heat of the refrigerant can be transferred to the water flowing through through the target heat exchanger, thereby achieving heating of the water flowing through. In the cooling scenario, the refrigerant absorbs heat from the water flowing through, and the heat of the refrigerant can be transferred to the outside world through the target heat exchanger, thereby achieving cooling of the water flowing through.

[0077] In a possible implementation, when the auxiliary expansion valve of the jet enthalpy heat pump system is opened, the control chip obtains the outlet water temperature of the target heat exchanger through a temperature sensor at the outlet of the target heat exchanger.

[0078] In this implementation, the outlet water temperature can be quickly acquired using the temperature sensor, and the acquisition efficiency of the outlet water temperature is high.

[0079] 303. When the outlet water temperature is greater than or equal to the outlet water temperature threshold, the control chip determines whether the exhaust temperature of the compressor tends to be stable.

[0080] Among them, the outlet water temperature is greater than or equal to the outlet water temperature threshold, which means that the outlet water temperature is high, the energy transferred by the refrigerant to the water is relatively limited, and the temperature of the refrigerant after passing through the target heat exchanger may still be relatively high. Then, after the refrigerant enters the auxiliary circuit, even if the temperature and pressure are reduced by the auxiliary expansion valve, the temperature is still high. In this way, when the refrigerant in the auxiliary circuit enters the compressor, the exhaust temperature of the compressor will be quickly increased. The outlet water temperature threshold is set by the technician according to the actual situation, such as 50°C, etc., and the embodiment of the present application does not limit this. Determining whether the exhaust temperature tends to be stable can improve the accuracy of the subsequent control of the auxiliary expansion valve. This is because the exhaust temperature of the compressor will be used to control the auxiliary expansion valve in the future. When the exhaust temperature of the compressor tends to be stable, the credibility of the exhaust temperature of the compressor is high, so the accuracy of controlling the auxiliary expansion valve is also high; when the exhaust temperature of the compressor is not stable, the credibility of the exhaust temperature of the compressor is low, so the accuracy of controlling the auxiliary expansion valve is also low.

[0081] In a possible implementation, when the outlet water temperature is greater than or equal to the outlet water temperature threshold, the control chip controls the auxiliary expansion valve to open to a first opening at a first rate, and the first opening is the opening when the auxiliary expansion valve is fully opened. In the process of the auxiliary expansion valve opening at the first rate, the control chip obtains the first refrigerant temperature of the refrigerant in the auxiliary circuit before the economizer of the jet enthalpy heat pump system completes the heat exchange and the second refrigerant temperature after the economizer completes the heat exchange. When the difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold, the control chip controls the auxiliary expansion valve to close to a second opening at a second rate, and the second opening is one tenth of the first opening. After a preset period of time, the control chip determines whether the exhaust temperature of the compressor tends to stabilize.

[0082] Among them, under normal circumstances, the exhaust temperature of the compressor can be lowered after the auxiliary expansion valve is opened. This is because when the refrigerant circulates in the auxiliary circuit, it will be reduced in pressure and temperature by the auxiliary expansion valve to become a medium-temperature and medium-pressure refrigerant. The medium-temperature and medium-pressure refrigerant is sprayed into the compressor, which can reduce the temperature of the refrigerant after one compression, thereby reducing the exhaust temperature of the compressor. Therefore, when the outlet water temperature is high, the auxiliary expansion valve is controlled to open at a first rate to fully open, thereby trying to reduce the exhaust temperature of the compressor. The auxiliary expansion valve is controlled to open at a first rate to ensure the speed of the increase of the refrigerant in the auxiliary circuit, thereby controlling the speed of the refrigerant in the auxiliary circuit being sprayed into the compressor and improving the stability of the compressor. The first rate is set by the technician according to the actual situation, such as being set to open 10% per second, and the embodiment of the present application is not limited to this. In the economizer, the refrigerants in the main circuit and the auxiliary circuit will undergo heat exchange, see Figure 1, the refrigerant in the main circuit of the economizer is the high-temperature and high-pressure refrigerant after passing through the target heat exchanger, and the refrigerant in the auxiliary circuit of the economizer is the medium-temperature and medium-pressure refrigerant after passing through the auxiliary circuit expansion valve. Therefore, the refrigerant in the main circuit can transfer heat to the refrigerant in the auxiliary circuit. The first refrigerant temperature is the temperature of the refrigerant in the auxiliary circuit before entering the economizer, and the second refrigerant temperature is the temperature of the refrigerant in the auxiliary circuit flowing out of the economizer. The difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold, indicating that the refrigerant in the auxiliary circuit absorbs less heat in the economizer and the temperature rises less; the difference between the second refrigerant temperature and the first refrigerant temperature is greater than the refrigerant temperature threshold, indicating that the refrigerant in the auxiliary circuit absorbs more heat in the economizer and the temperature rises more. The refrigerant temperature threshold is set by the technician according to the actual situation, such as 1°C, etc., and the embodiment of the present application does not limit this. Controlling the auxiliary circuit expansion valve to close to the second opening at the second rate is to reduce the flow rate of the refrigerant in the auxiliary circuit, thereby reducing the amount of refrigerant in the auxiliary circuit sprayed into the compressor. The auxiliary circuit expansion valve is controlled to close at the second rate in order to ensure the speed at which the refrigerant in the auxiliary circuit is reduced, thereby controlling the speed at which the refrigerant in the auxiliary circuit is sprayed into the compressor, and improving the stability of the compressor. In some embodiments, the first rate and the second rate are the same. In addition, the preset time length is set by the technician according to the actual situation, such as being set to 10s, etc., and the embodiments of the present application are not limited to this.

[0083] In this implementation, when the outlet water temperature is high, the auxiliary circuit expansion valve is controlled to be fully opened at the first rate to increase the flow rate of the refrigerant in the auxiliary circuit. During the opening of the auxiliary circuit expansion valve, the first refrigerant temperature and the second refrigerant temperature of the refrigerant in the auxiliary circuit are obtained, and the difference between the first refrigerant temperature and the second refrigerant temperature and the refrigerant temperature threshold are used to control the auxiliary circuit expansion valve and determine whether the exhaust temperature tends to be stable, with high accuracy.

[0084] For example, when the outlet water temperature is greater than or equal to the outlet water temperature threshold, the control chip sends a first instruction to the auxiliary expansion valve, the first instruction carries the first rate and the first opening, so as to control the auxiliary expansion valve to open to the first opening at the first rate. In the process of the auxiliary expansion valve opening at the first rate, the control chip obtains the first refrigerant temperature through the first temperature sensor installed in the economizer, and obtains the second refrigerant temperature through the second temperature sensor installed in the economizer. The first temperature sensor is installed at the entrance of the auxiliary circuit entering the economizer, and the second temperature sensor is installed at the outlet of the auxiliary circuit passing through the economizer. When the difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold, the control chip sends a second instruction to the auxiliary expansion valve, the second instruction carries the second rate and the second opening, so as to control the auxiliary expansion valve to close to the second opening at the second rate. After a preset time, the control chip determines whether the exhaust temperature of the compressor tends to be stable.

[0085] In order to explain the above step 303 more clearly, the method of determining whether the exhaust temperature of the compressor tends to be stable in the above step 303 is explained below.

[0086] In a possible implementation, the control chip acquires N exhaust temperatures of the compressor, where the N exhaust temperatures are continuously collected exhaust temperatures, and N is a positive integer. The control chip determines the average exhaust temperature of the first N-1 exhaust temperatures among the N exhaust temperatures. When the difference between the Nth exhaust temperature among the N exhaust temperatures and the average exhaust temperature is within a preset temperature range, the control chip determines that the exhaust temperature of the compressor tends to be stable. When the difference between the Nth exhaust temperature among the N exhaust temperatures and the average exhaust temperature is not within the preset temperature range, the control chip determines that the exhaust temperature of the compressor does not tend to be stable.

[0087] Among them, N and the preset temperature range are set by technicians according to actual conditions, for example, N is set to 11 and the preset temperature range is set to (-0.2, 0.2), and this embodiment of the present application does not limit this.

[0088] For example, the above implementation can be described as controlling the chip based on whether the exhaust temperature meets the preset condition. Taking N as 11 and the preset temperature range as (-0.2, 0.2) as an example, the preset condition is expressed by the following formula (1).

[0089] T p (N) ± 0.2 = [T p (N-1)+......T p (N-10)] / 10 (1)

[0090] When the exhaust temperature meets the preset conditions, the control chip determines that the exhaust temperature of the compressor tends to be stable. When the exhaust temperature does not meet the preset conditions, the control chip determines that the exhaust temperature of the compressor does not tend to be stable.

[0091] Optionally, based on the above implementation, the following steps can also be performed.

[0092] In a possible implementation manner, when the difference between the second refrigerant temperature and the first refrigerant temperature is greater than the refrigerant temperature threshold, the control chip controls the auxiliary expansion valve to continue operating at the current opening.

[0093] Optionally, based on the above implementation, after controlling the auxiliary expansion valve to continue to operate at the current opening, the control chip controls the auxiliary expansion valve with a default control logic.

[0094] In addition, after step 302, in addition to being able to execute the above step 303, the following steps can also be executed.

[0095] In a possible implementation manner, when the outlet water temperature is lower than the outlet water temperature threshold, the control chip controls the auxiliary expansion valve using a default control logic.

[0096] Optionally, after step 303, the control chip can execute the following step 304 or 305 according to actual conditions.

[0097] 304. When the exhaust temperature of the compressor tends to be stable, the control chip determines whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to a reference exhaust temperature, and the reference exhaust temperature is less than the exhaust protection temperature of the compressor.

[0098] Among them, the reference exhaust temperature is equivalent to an exhaust temperature limit. When the exhaust temperature exceeds the reference exhaust temperature, the compressor may experience frequency reduction and exhaust temperature protection, thereby affecting the stability of the jet enthalpy heat pump system. The exhaust protection temperature of the compressor can be regarded as the upper limit of the exhaust temperature of the compressor. When the exhaust temperature reaches or exceeds the exhaust protection temperature, the compressor will trigger the exhaust temperature protection, that is, the compressor will stop working to prevent damage. The exhaust protection temperature is associated with the model of the compressor, and the embodiment of the present application does not limit this. The difference between the reference exhaust temperature and the exhaust protection temperature is set by the technician according to the actual situation. For example, the reference exhaust temperature is set to be 10°C lower than the exhaust protection temperature. The embodiment of the present application does not limit this.

[0099] In a possible implementation, when the exhaust temperature of the compressor tends to be stable, the control chip compares the exhaust temperature of the compressor with the reference exhaust temperature to determine whether the exhaust temperature is greater than or equal to the reference exhaust temperature.

[0100] In the above embodiment, the exhaust temperature is compared with the reference exhaust temperature instead of the exhaust temperature with the exhaust protection temperature in order to leave a certain temperature space for the control of the auxiliary expansion valve to prevent the compressor from stopping directly due to excessively high exhaust temperature.

[0101] 305. When the exhaust temperature of the compressor has not stabilized, the control chip waits for the exhaust temperature of the compressor to stabilize before determining whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature.

[0102] Among them, the method of judging whether the exhaust temperature tends to be stable in step 305 belongs to the same inventive concept as the above step 303, and the method of judging whether the exhaust temperature is greater than or equal to the reference exhaust temperature belongs to the same inventive concept as the above step 304, and the implementation process is not repeated here.

[0103] 306. When the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, the control chip controls the auxiliary expansion valve to close.

[0104] Among them, the exhaust temperature is greater than or equal to the reference exhaust temperature, which means that the exhaust temperature is relatively high. When the auxiliary expansion valve is opened, it means that the jet reheat function is turned on. The refrigerant in the auxiliary circuit will enter the compressor, making the compressor's one compression process become a two-compression process, increasing the compression ratio of the refrigerant, and also increasing the temperature of the refrigerant after compression. Therefore, when the exhaust temperature of the compressor is high, close the auxiliary expansion valve to turn off the jet reheat function to prevent the exhaust temperature from rising rapidly, reduce the exhaust temperature of the compressor, and reduce the probability of the compressor reducing frequency and triggering the exhaust temperature protection.

[0105] In a possible implementation manner, when the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, the control chip sends a third control instruction to the auxiliary expansion valve to control the auxiliary expansion valve to close.

[0106] 307. When the exhaust temperature of the compressor is lower than the reference exhaust temperature, the control chip controls the opening of the auxiliary expansion valve to increase a third opening.

[0107] Among them, the exhaust temperature is lower than the reference exhaust temperature, which means that the exhaust temperature is low. At this time, the capacity of the compressor can be fully utilized by increasing the flow rate of the refrigerant in the auxiliary circuit, thereby improving the heating effect. At this time, the opening of the auxiliary circuit expansion valve is controlled to increase the third opening to increase the flow rate of the refrigerant in the auxiliary circuit. The third opening is set by the technician according to the actual situation, such as being set to 1% of the first opening, etc., and the embodiments of the present application are not limited to this.

[0108] In a possible implementation, when the exhaust temperature of the compressor is lower than the reference exhaust temperature, the control chip sends a fourth control instruction to the auxiliary expansion valve, and the fourth control instruction carries the third opening degree to control the auxiliary expansion valve to continue opening the third opening degree.

[0109] 308. The control chip re-determines whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature.

[0110] Among them, in step 307, the opening of the auxiliary expansion valve is adjusted. The adjustment of the opening of the auxiliary expansion valve will cause the change of the refrigerant flow in the auxiliary circuit, thereby affecting the exhaust temperature of the compressor. Therefore, it is necessary to use the above-mentioned step 308 to determine again whether the exhaust temperature of the compressor is too high.

[0111] In a possible implementation, the control chip determines whether the exhaust temperature of the compressor tends to be stable. If the exhaust temperature of the compressor tends to be stable, the control chip re-determines whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature. If the exhaust temperature of the compressor does not tend to be stable, the control chip waits for the exhaust temperature of the compressor to stabilize and then re-determines whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature.

[0112] Among them, the method of judging whether the exhaust temperature tends to be stable in the above embodiment belongs to the same inventive concept as the above step 303, and the method of judging whether the exhaust temperature is greater than or equal to the reference exhaust temperature belongs to the same inventive concept as the above step 304, and the implementation process will not be repeated.

[0113] Optionally, after step 303, the control chip can execute the following step 309 or 310 according to actual conditions.

[0114] 309. When the re-determined exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, the control chip controls the auxiliary expansion valve to continue operating at the current opening.

[0115] 310. When the re-determined exhaust temperature of the compressor is lower than the reference exhaust temperature, the control chip obtains a first refrigerant temperature of the refrigerant in the auxiliary circuit before the economizer of the jet enthalpy heat pump system completes heat exchange and a second refrigerant temperature of the refrigerant after the economizer completes heat exchange.

[0116] Among them, in step 307, the opening of the auxiliary expansion valve is adjusted. The adjustment of the opening of the auxiliary expansion valve will cause the change of the refrigerant flow in the auxiliary circuit and the main circuit. Therefore, the first refrigerant temperature and the second refrigerant temperature of the refrigerant in the auxiliary circuit of the economizer will also change accordingly. Before performing subsequent judgments, it is necessary to re-acquire the first refrigerant temperature and the second refrigerant temperature.

[0117] 311. The control chip controls the auxiliary expansion valve based on the difference between the first refrigerant temperature and the second refrigerant temperature.

[0118] In a possible implementation, when the difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold, the control chip controls the auxiliary expansion valve to continue to operate at the current opening. When the difference between the second refrigerant temperature and the first refrigerant temperature is greater than the refrigerant temperature threshold, the control chip controls the opening of the auxiliary expansion valve to increase the third opening.

[0119] After the auxiliary expansion valve is controlled to continue to work at the current opening, the control chip controls the auxiliary expansion valve with the default control logic. In addition, controlling the opening of the auxiliary expansion valve to increase the third opening is actually equivalent to returning to step 307 in a loop.

[0120] In order to more clearly illustrate the technical solution provided in the embodiment of the present application, Figure 4 The technical solution provided in the embodiment of the present application is described in detail. Figure 4 , when the jet enthalpy heat pump system is running and the auxiliary expansion valve opening conditions are met, the outlet water temperature T of the target heat exchanger is obtained out At the outlet water temperature T out When the outlet water temperature is less than the threshold value Y, the control chip controls the auxiliary expansion valve with the default control logic. out When the temperature is greater than or equal to the outlet water temperature threshold value Y, the control chip controls the auxiliary expansion valve to open at a first rate s1 to a first opening degree k1. During the opening of the auxiliary expansion valve, the control chip obtains the first refrigerant temperature T of the refrigerant in the auxiliary circuit. 9i1 and the second refrigerant temperature T 9o1 , and determine the first refrigerant temperature T 9i1 and the second refrigerant temperature T 9o1 Is the difference between the two values ​​less than or equal to the refrigerant temperature threshold Tt At the first refrigerant temperature T 9i1 and the second refrigerant temperature T 9o1 The difference between them is less than or equal to the refrigerant temperature threshold T t In the case of the first refrigerant temperature T, the control chip controls the auxiliary expansion valve to maintain the current opening, and controls the auxiliary expansion valve with the default control logic. 9i1 and the second refrigerant temperature T 9o1 The difference between them is greater than the refrigerant temperature threshold T t In the case of, the control chip controls the auxiliary expansion valve to close to the second opening degree k2 at the second rate s2. After 10s (preset time), the exhaust temperature T of the compressor is detected. p , until the exhaust temperature of the compressor tends to be stable, and the exhaust temperature T at this time is determined. p1 Is it greater than or equal to X-10, where X is the exhaust protection temperature and X-10 is the reference exhaust temperature. p1 When the exhaust temperature is greater than or equal to X-10, the control chip controls the auxiliary expansion valve to close. p1 When the temperature is less than X-10, the control chip controls the opening of the auxiliary expansion valve to increase the third opening k3. After 10s, the exhaust temperature T of the compressor is re-detected. p , until the exhaust temperature of the compressor tends to be stable, and the exhaust temperature T at this time is determined p2 Is it greater than or equal to X-10? p2 When the exhaust temperature is greater than or equal to X-10, the control chip controls the auxiliary expansion valve to maintain the current opening. p2 When the temperature is less than X-10, the control chip re-acquires the first refrigerant temperature T of the refrigerant in the auxiliary circuit. 9i2 and the second refrigerant temperature T 9o2 , and determine the first refrigerant temperature T 9i2 and the second refrigerant temperature T 9o2 Is the difference between the two values ​​less than or equal to the refrigerant temperature threshold T t At the first refrigerant temperature T 9i2 and the second refrigerant temperature T 9o2 The difference between them is less than or equal to the refrigerant temperature threshold T t In the case of the first refrigerant temperature T, the control chip controls the auxiliary expansion valve to maintain the current opening, and controls the auxiliary expansion valve with the default control logic. 9i2 and the second refrigerant temperature T 9o2 The difference between them is greater than the refrigerant temperature threshold T t In this case, the control chip controls the opening of the auxiliary expansion valve to increase the third opening k3.

[0121] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.

[0122] Through the technical solution provided in the embodiment of the present application, when the jet enthalpy increase function is turned on in the jet enthalpy increase heat pump system, it is determined whether the outlet water temperature of the target radiator is greater than or equal to the outlet water temperature threshold. When the outlet water temperature is greater than or equal to the outlet water temperature threshold, it means that the outlet water temperature is high, and it is determined whether the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, that is, whether the exhaust temperature of the compressor is high. When the exhaust temperature of the compressor is high, the auxiliary expansion valve is closed to terminate the circulation of the refrigerant in the auxiliary circuit to prevent the exhaust temperature of the compressor from rising rapidly, thereby reducing the probability of the compressor reducing frequency and triggering the exhaust temperature protection, and thus improving the stability of the jet enthalpy increase heat pump system.

[0123] Figure 5 is a schematic diagram of the structure of a control device for an auxiliary expansion valve provided in an embodiment of the present application, see Figure 5 The device includes: an acquisition module 501, a determination module 502 and a control module 503.

[0124] The acquisition module 501 is used to acquire the outlet water temperature of the target heat exchanger of the jet enthalpy heat pump system when the auxiliary expansion valve of the jet enthalpy heat pump system is opened. The target heat exchanger is used to change the temperature of the water flowing through the target heat exchanger.

[0125] The determination module 502 is used to determine whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature when the outlet water temperature is greater than or equal to the outlet water temperature threshold, and the reference exhaust temperature is less than the exhaust protection temperature of the compressor.

[0126] The control module 503 is used to control the auxiliary expansion valve to close when the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature.

[0127] In a possible implementation, the determination module 502 is used to determine whether the exhaust temperature of the compressor tends to be stable when the outlet water temperature is greater than or equal to the outlet water temperature threshold. When the exhaust temperature of the compressor tends to be stable, determine whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature. When the exhaust temperature of the compressor does not tend to be stable, wait until the exhaust temperature of the compressor tends to be stable before determining whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature.

[0128] In a possible implementation, the determination module 502 is used to control the auxiliary expansion valve to open to a first opening at a first rate when the outlet water temperature is greater than or equal to the outlet water temperature threshold, and the first opening is the opening when the auxiliary expansion valve is fully opened. In the process of the auxiliary expansion valve opening at the first rate, the first refrigerant temperature of the refrigerant in the auxiliary circuit before the economizer of the jet enthalpy heat pump system completes the heat exchange and the second refrigerant temperature after the economizer completes the heat exchange. When the difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold, the auxiliary expansion valve is controlled to close to a second opening at a second rate, and the second opening is one tenth of the first opening. After a preset period of time, determine whether the exhaust temperature of the compressor tends to stabilize.

[0129] In a possible implementation, the control module 503 is further configured to control the auxiliary expansion valve to continue operating at a current opening when a difference between the second refrigerant temperature and the first refrigerant temperature is greater than the refrigerant temperature threshold.

[0130] In a possible implementation, the determination module 502 is used to obtain N exhaust temperatures of the compressor, where the N exhaust temperatures are continuously collected exhaust temperatures, and N is a positive integer. The average exhaust temperature of the first N-1 exhaust temperatures among the N exhaust temperatures is determined. When the difference between the Nth exhaust temperature among the N exhaust temperatures and the average exhaust temperature is within a preset temperature range, it is determined that the exhaust temperature of the compressor tends to be stable. When the difference between the Nth exhaust temperature among the N exhaust temperatures and the average exhaust temperature is not within the preset temperature range, it is determined that the exhaust temperature of the compressor does not tend to be stable.

[0131] In a possible implementation, the control module 503 is further configured to control the opening of the auxiliary expansion valve to increase a third opening when the exhaust temperature of the compressor is lower than the reference exhaust temperature.

[0132] In a possible implementation, the determination module 502 is further configured to re-determine whether the exhaust temperature of the compressor of the injection enthalpy heat pump system is greater than or equal to a reference exhaust temperature.

[0133] The control module 503 is also used to control the auxiliary circuit expansion valve to continue to work at the current opening when the re-determined exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature. When the re-determined exhaust temperature of the compressor is less than the reference exhaust temperature, the first refrigerant temperature of the refrigerant in the auxiliary circuit before the economizer of the jet enthalpy heat pump system completes the heat exchange and the second refrigerant temperature after the economizer completes the heat exchange. Based on the difference between the first refrigerant temperature and the second refrigerant temperature, the auxiliary circuit expansion valve is controlled.

[0134] In a possible implementation, the control module 503 is further configured to control the auxiliary expansion valve to continue to operate at the current opening when the difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold. When the difference between the second refrigerant temperature and the first refrigerant temperature is greater than the refrigerant temperature threshold, control the opening of the auxiliary expansion valve to further increase the third opening.

[0135] In a possible implementation, the determination module 502 is further used to determine whether the exhaust temperature of the compressor tends to be stable. If the exhaust temperature of the compressor tends to be stable, it is re-determined whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature. If the exhaust temperature of the compressor does not tend to be stable, it is waited until the exhaust temperature of the compressor tends to be stable before re-determining whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature.

[0136] It should be noted that: the control device for the auxiliary expansion valve provided in the above embodiment only uses the division of the above functional modules as an example when controlling the auxiliary expansion valve. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the control chip is divided into different functional modules to complete all or part of the functions described above. In addition, the control device for the auxiliary expansion valve provided in the above embodiment and the control method embodiment of the auxiliary expansion valve belong to the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0137] Through the technical solution provided in the embodiment of the present application, when the jet enthalpy increase function is turned on in the jet enthalpy increase heat pump system, it is determined whether the outlet water temperature of the target radiator is greater than or equal to the outlet water temperature threshold. When the outlet water temperature is greater than or equal to the outlet water temperature threshold, it means that the outlet water temperature is high, and it is determined whether the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, that is, whether the exhaust temperature of the compressor is high. When the exhaust temperature of the compressor is high, the auxiliary expansion valve is closed to terminate the circulation of the refrigerant in the auxiliary circuit to prevent the exhaust temperature of the compressor from rising rapidly, thereby reducing the probability of the compressor reducing frequency and triggering the exhaust temperature protection, and thus improving the stability of the jet enthalpy increase heat pump system.

[0138] Figure 6 6 is a schematic diagram of a heat pump structure provided by an embodiment of the present application. Generally, the heat pump includes a control chip 600 , and the control chip 600 includes: one or more processors 601 and one or more memories 602 .

[0139] The processor 601 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 601 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor 601 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 601 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 601 may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning.

[0140] The memory 602 may include one or more computer-readable storage media, which may be non-transitory. The memory 602 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In some embodiments, the non-transitory computer-readable storage medium in the memory 602 is used to store at least one computer program, which is used to be executed by the processor 601 to implement the control method of the auxiliary expansion valve provided in the method embodiment of the present application.

[0141] Those skilled in the art will understand that Figure 6 The structure shown in the figure does not constitute a limitation on the control chip 600, and may include more or less components than those shown in the figure, or combine certain components, or adopt a different component arrangement.

[0142] In an exemplary embodiment, a computer-readable storage medium is also provided, such as a memory including a computer program, and the computer program can be executed by a processor to complete the control method of the auxiliary expansion valve in the above embodiment. For example, the computer-readable storage medium can be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), a magnetic tape, a floppy disk, an optical data storage device, etc.

[0143] In an exemplary embodiment, a computer program product or a computer program is also provided, which includes a program code, and the program code is stored in a computer-readable storage medium. The processor of the control chip reads the program code from the computer-readable storage medium, and the processor executes the program code, so that the control chip executes the above-mentioned control method of the auxiliary expansion valve.

[0144] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware or by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0145] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A control method for an auxiliary expansion valve, characterized in that: The method comprises: When the auxiliary expansion valve of the jet enthalpy heat pump system is opened, obtaining the outlet water temperature of the target heat exchanger of the jet enthalpy heat pump system, wherein the target heat exchanger is used to change the temperature of the water flowing through the target heat exchanger; In the case where the outlet water temperature is greater than or equal to the outlet water temperature threshold, determining whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to a reference exhaust temperature, and the reference exhaust temperature is less than an exhaust protection temperature of the compressor; When the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, the auxiliary expansion valve is controlled to be closed.

2. The method according to claim 1, characterized in that The step of determining whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to a reference exhaust temperature when the outlet water temperature is greater than or equal to an outlet water temperature threshold comprises: When the outlet water temperature is greater than or equal to the outlet water temperature threshold, determining whether the exhaust temperature of the compressor tends to be stable; When the exhaust temperature of the compressor tends to be stable, determining whether the exhaust temperature of the compressor of the injection enthalpy heat pump system is greater than or equal to a reference exhaust temperature; In the case that the exhaust temperature of the compressor has not stabilized, it is determined whether the exhaust temperature of the compressor of the injection enthalpy heat pump system is greater than or equal to the reference exhaust temperature after the exhaust temperature of the compressor stabilizes.

3. The method according to claim 2, characterized in that When the outlet water temperature is greater than or equal to the outlet water temperature threshold, determining whether the exhaust temperature of the compressor tends to be stable includes: When the outlet water temperature is greater than or equal to the outlet water temperature threshold, controlling the auxiliary expansion valve to open at a first rate to a first opening degree, wherein the first opening degree is the opening degree when the auxiliary expansion valve is fully opened; In the process of the auxiliary circuit expansion valve being opened at the first rate, obtaining a first refrigerant temperature of the refrigerant in the auxiliary circuit before the economizer of the jet enthalpy heat pump system completes heat exchange and a second refrigerant temperature after the economizer completes heat exchange; When the difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold, controlling the auxiliary expansion valve to close to a second opening degree at a second rate, wherein the second opening degree is one tenth of the first opening degree; After a preset time period, it is determined whether the exhaust temperature of the compressor tends to be stable.

4. The method according to claim 3, characterized in that: The method further comprises: When the difference between the second refrigerant temperature and the first refrigerant temperature is greater than the refrigerant temperature threshold, the auxiliary circuit expansion valve is controlled to continue operating at the current opening.

5. The method according to any one of claims 2 to 4, characterized in that: The step of determining whether the exhaust gas temperature of the compressor tends to be stable comprises: Acquire N exhaust temperatures of the compressor, where the N exhaust temperatures are continuously collected exhaust temperatures, and N is a positive integer; Determining an average exhaust temperature of first N-1 exhaust temperatures among the N exhaust temperatures; When a difference between an Nth exhaust temperature among the N exhaust temperatures and the average exhaust temperature is within a preset temperature range, determining that the exhaust temperature of the compressor tends to be stable; When the difference between the Nth exhaust temperature among the N exhaust temperatures and the average exhaust temperature is not within the preset temperature range, it is determined that the exhaust temperature of the compressor is not stable.

6. The method according to claim 1, characterized in that The method further comprises: When the exhaust temperature of the compressor is lower than the reference exhaust temperature, the opening degree of the auxiliary expansion valve is controlled to increase by a third opening degree.

7. The method according to claim 6, characterized in that After controlling the opening degree of the auxiliary expansion valve to increase by a third opening degree when the exhaust temperature of the compressor is lower than the reference exhaust temperature, the method further includes: re-determining whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature; When the re-determined exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature, controlling the auxiliary expansion valve to continue operating at the current opening; When the re-determined exhaust temperature of the compressor is lower than the reference exhaust temperature, the first refrigerant temperature of the refrigerant in the auxiliary circuit before the economizer of the jet enthalpy heat pump system completes the heat exchange and the second refrigerant temperature after the economizer completes the heat exchange are obtained; based on the difference between the first refrigerant temperature and the second refrigerant temperature, the auxiliary circuit expansion valve is controlled.

8. The method according to claim 7, characterized in that The controlling the auxiliary expansion valve based on the difference between the first refrigerant temperature and the second refrigerant temperature includes: When the difference between the second refrigerant temperature and the first refrigerant temperature is less than or equal to the refrigerant temperature threshold, controlling the auxiliary circuit expansion valve to continue operating at the current opening; When the difference between the second refrigerant temperature and the first refrigerant temperature is greater than the refrigerant temperature threshold, the opening degree of the auxiliary expansion valve is controlled to further increase the third opening degree.

9. The method according to claim 7, characterized in that: Before re-determining whether the exhaust temperature of the compressor of the injection enthalpy heat pump system is greater than or equal to the reference exhaust temperature, the method further includes: Determining whether the exhaust temperature of the compressor is stable; The re-determining whether the exhaust temperature of the compressor of the injection enthalpy heat pump system is greater than or equal to the reference exhaust temperature includes: When the exhaust temperature of the compressor tends to be stable, re-determining whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to the reference exhaust temperature; In the case that the exhaust temperature of the compressor is not stable, it is necessary to wait until the exhaust temperature of the compressor is stable before re-determining whether the exhaust temperature of the compressor of the injection enthalpy heat pump system is greater than or equal to the reference exhaust temperature.

10. A control device for an auxiliary expansion valve, characterized in that: The device comprises: An acquisition module, used for acquiring the outlet water temperature of a target heat exchanger of the jet enthalpy heat pump system when the auxiliary expansion valve of the jet enthalpy heat pump system is opened, wherein the target heat exchanger is used for changing the temperature of water flowing through the target heat exchanger; a determination module, configured to determine, when the outlet water temperature is greater than or equal to an outlet water temperature threshold, whether the exhaust temperature of the compressor of the jet enthalpy heat pump system is greater than or equal to a reference exhaust temperature, and the reference exhaust temperature is less than an exhaust protection temperature of the compressor; The control module is used to control the auxiliary expansion valve to close when the exhaust temperature of the compressor is greater than or equal to the reference exhaust temperature.

11. A heat pump, characterized in that: The heat pump includes a control chip, which includes one or more processors and one or more memories, wherein at least one computer program is stored in the one or more memories, and the computer program is loaded and executed by the one or more processors to implement the control method of the auxiliary expansion valve as described in any one of claims 1 to 9.

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