A heat pump system with adaptive evaporation capacity

Abstract

This invention relates to an adaptive evaporation capacity heat pump system. By dynamically adjusting the evaporator area and refrigerant flow rate in real time based on the evaporator's heat load demand, it adapts to different heat load requirements, thereby protecting the compressor from overheating or liquid slugging damage. Specifically, it includes determining the electronic expansion valve connected to the heat pump system based on the heat load demand, setting the initial opening, and adjusting the opening of the electronic expansion valve using parameters such as return gas superheat to control the refrigerant flow rate; the system continuously monitors the circulating water return temperature to redetermine the required electronic expansion valve, and dynamically adjusts the evaporator area and refrigerant flow rate to adapt to changes in heat load demand, ensuring safe compressor operation; simultaneously, it synchronously monitors the exhaust superheat ΔT in real time. p To prevent exhaust overheating ΔT p Excessive heat pump levels can have a series of negative effects on the system, so it is important to ensure the safe operation of the system.

Description

Technical Field

[0001] This invention relates to the field of heat pump technology, and in particular to a heat pump system with adaptive evaporation capacity. Background Technology

[0002] Ground source heat pump water heaters can be used for hot water supply in residential and commercial buildings. They provide a stable temperature, and because the water source temperature is relatively stable, the heat pump operates more reliably and efficiently. Their working principle involves a refrigerant absorbing heat from the water flowing through the evaporator, which is then heated by the compressor and released into the hot water storage tank.

[0003] Currently, evaporators can absorb heat from various low-temperature media during operation. For example, WO2022267814A1 proposes a temperature control system coupled to a heat pump water heater. This system couples the evaporator to the return pipe of the indoor heating system. The refrigerant in the evaporator absorbs heat from the circulating water, changing from a liquid to a gaseous state. After being compressed, it becomes a high-temperature, high-pressure gas, which then flows through the water tank heat exchanger to heat the water in the tank, thus providing domestic hot water. However, with this temperature control system, significant differences in user applications within the indoor heating system, including varying house sizes and the number and type of heat exchanger units (such as underfloor heating, radiators, and fan coil units), can lead to drastic variations in the temperature and flow rate of the circulating water in the return pipe.

[0004] In existing technologies, traditional water source heat pump water heater systems typically use a single expansion valve to control the flow of refrigerant into the evaporator, which has a fixed volume. While this system design is simple, it has certain limitations. A single expansion valve and a fixed-volume evaporator may not be sufficient to dynamically adjust the evaporator's capacity according to the actual heat load, affecting the stability and lifespan of the compressor. Therefore, there is an urgent need to optimize the evaporator and propose corresponding control methods. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to overcome the defects or deficiencies of the prior art and provide a heat pump system with adaptive evaporation capacity.

[0006] An adaptive evaporation capacity heat pump system includes a compressor, a condenser, a first electronic expansion valve and a second electronic expansion valve connected in parallel, and an evaporator with an adjustable evaporation area, all connected by a refrigerant circulation pipeline. The first electronic expansion valve controls the flow rate of refrigerant flowing through the larger evaporation area, and the second electronic expansion valve controls the flow rate of refrigerant flowing through the smaller evaporation area. The system also includes a pressure detection module, a temperature detection module, a switching module, and a controller communicatively connected to the compressor, the first electronic expansion valve, the second electronic expansion valve, the pressure detection module, the temperature detection module, and the switching module. The controller adaptively controls the evaporation capacity of the heat pump system in the following manner:

[0007] Get the current circulating water return temperature T i If the current circulating water return temperature T i Greater than the evaporation temperature T z If the condition is met, the second electronic expansion valve will be activated; otherwise, the first electronic expansion valve will be activated.

[0008] After the system has been running for a period of time, based on the current return gas temperature T... s With evaporation temperature T z Calculate the return gas superheat ΔT s And based on the return gas superheat ΔT s Adjust the opening degree of the activated electronic expansion valve to continuously obtain the circulating water return temperature T at the next moment. i .

[0009] Compared to existing technologies, the heat pump system with adaptive evaporation capacity proposed in this invention can dynamically adjust the evaporator capacity according to the actual heat load, solving the problems of accelerated wear of compressor components caused by superheated steam entering the compressor, and liquid slugging caused by liquid or wet steam entering the compressor. This protects the compressor, improves the energy efficiency of the heat pump system, and extends the service life of the equipment.

[0010] Specifically, based on the current return gas temperature T s With evaporation temperature T z Calculate the return gas superheat ΔT s Determine the current superheat ΔT of the return gas. s With the target superheat ΔT s-set Relationship:

[0011] For example, the current superheat of the return gas ΔT s Greater than the target superheat ΔT s-set This increases the opening degree of the electronic expansion valve;

[0012] For example, the current superheat of the return gas ΔT s Equal to the target superheat ΔT s-set If so, the opening degree of the electronic expansion valve remains unchanged;

[0013] For example, the current superheat of the return gas ΔT s Less than the target superheat ΔT s-set This reduces the opening degree of the electronic expansion valve.

[0014] Furthermore, when the second electronic expansion valve is activated, the opening degree of the second electronic expansion valve is obtained. If its opening degree is less than or equal to the minimum allowable opening degree and is maintained for more than 10 seconds, the second electronic expansion valve is closed and the first electronic expansion valve is activated.

[0015] Furthermore, when the first electronic expansion valve is activated, the opening degree of the first electronic expansion valve is obtained. If the opening degree is greater than or equal to the maximum allowable opening degree and is maintained for more than 10 seconds, the first electronic expansion valve is closed and the second electronic expansion valve is activated.

[0016] Furthermore, it also includes the system's startup control method: obtaining the current actual water tank temperature T. t The status of the target-type flow switch and the current circulating water return temperature T. i The compressor's downtime, if it satisfies: the actual water tank temperature T at the current moment... t Less than or equal to the water tank set temperature T t-set Temperature difference between start and stop ΔT qt The difference between them, the target flow switch being on, and the current circulating water return temperature T i Greater than the minimum return water temperature T i-low If the compressor has been off for more than 3 minutes, start the system.

[0017] Furthermore, it also includes controlling the opening of the electronic expansion valve based on the exhaust superheat: according to the actual exhaust temperature T at the current moment. p With condensation temperature T l Calculate exhaust superheat ΔT p Determine the exhaust superheat ΔT at the current moment. p Is it greater than the allowable valve opening temperature difference ΔT? k If the current exhaust superheat ΔT is satisfied... p Greater than the allowable valve opening temperature difference ΔT k Obtain the current opening degree of the electronic expansion valve and determine whether the current opening degree of the electronic expansion valve is greater than the maximum allowable opening degree:

[0018] If the opening degree of the electronic expansion valve at the current moment equals the maximum allowable opening degree, then the electronic expansion valve will maintain its current opening degree.

[0019] If the opening degree of the electronic expansion valve at the current moment is less than the maximum allowable opening degree, the electronic expansion valve will increase the opening degree according to a specific period and a specific increment.

[0020] In other cases, the opening of the electronic expansion valve remains unchanged.

[0021] Specifically, the water tank is set to temperature T. t-set The temperature is 55℃; the start-stop temperature difference ΔT qt The minimum return water temperature is 5℃; i-low The temperature is 7℃; the allowable valve opening temperature difference ΔT k The target temperature is 25℃; the target superheat ΔT s-set The temperature is 3℃.

[0022] Specifically, the evaporator includes a refrigerant pipeline through which the refrigerant flows and a circulating water pipeline through which the circulating water in the return water pipe of the indoor heating system flows. The evaporator is coupled to the return water pipe of the indoor heating system that flows through the user terminal heat exchanger. The circulating water in the return water pipe exchanges heat with the refrigerant in the refrigerant pipeline through the circulating water pipeline.

[0023] Furthermore, the refrigerant pipeline has a first inlet and a first outlet at both ends, a second inlet in the middle of the refrigerant pipeline, and a third inlet and a second outlet at both ends of the circulating water pipeline; the first electronic expansion valve is connected to the refrigerant pipeline through the first inlet, and the second electronic expansion valve is connected to the refrigerant pipeline through the second inlet; the compressor is connected to the refrigerant pipeline through the first outlet.

[0024] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a heat pump system structure according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the evaporator structure in a heat pump system according to an embodiment of the present invention;

[0027] Figure 3 This is a flowchart of an evaporator capacity adaptive control method according to an embodiment of the present invention;

[0028] Figure 4 This is a flowchart of a system startup control method according to an embodiment of the present invention;

[0029] Figure 5 This is a flowchart of a control method for controlling the opening of an electronic expansion valve based on exhaust superheat, according to an embodiment of the present invention. Detailed Implementation

[0030] When using a fixed-volume evaporator, if the temperature and flow rate of the return water pipe in the indoor heating system are too high, it means that the heat provided for exchanging with the refrigerant in the evaporator is excessive, leading to refrigerant overheating. This, in turn, causes the temperature of the vapor drawn into the compressor to rise, reducing the heating coefficient of the heat pump system, increasing the compressor's energy consumption, and long-term superheated steam entering the compressor will also accelerate the wear of compressor components and shorten its lifespan. Conversely, if the temperature and flow rate of the return water pipe in the indoor heating system are too low, it means that the heat provided for exchanging with the refrigerant in the evaporator is insufficient, resulting in incomplete refrigerant evaporation. Liquid or wet vapor may be drawn into the compressor, causing liquid slugging and severely damaging the compressor.

[0031] Therefore, the control method and device provided by the present invention change the evaporation area of ​​the evaporator according to the actual heat load, and at the same time adjust the refrigerant flow rate in combination with the opening of the electronic expansion valve, thereby dynamically and accurately adjusting the capacity of the evaporator and avoiding the negative impact of refrigerant overheating or insufficient evaporation on the compressor.

[0032] The present invention will now be described in detail with reference to the accompanying drawings.

[0033] like Figure 1 As shown, the heat pump system with adaptive evaporation capacity according to an embodiment of the present invention includes a compressor 110, a condenser 120, a filter 130, an electronic expansion valve assembly 140, an evaporator 150, a temperature detection module 160, a pressure detection module 170, a switch module 180, a control module 190, and other auxiliary pipes connected by a refrigerant circulation pipeline.

[0034] Specifically, the condenser 120 consists of a condenser coil 122 wound around the outer wall of the water tank 121.

[0035] Specifically, the electronic expansion valve assembly 140 includes a first electronic expansion valve 141 and a second electronic expansion valve 142, which are connected in parallel. One end of each is connected to the filter 130, and the other end is connected to the evaporator 150.

[0036] Specifically, such as Figure 2 As shown, the evaporator 150 includes a refrigerant pipe 151 through which refrigerant flows and a circulating water pipe 152 through which circulating water in the return water pipe of the indoor heating system flows. The refrigerant pipe 151 is provided with a first inlet A and a first outlet C at both ends, a second inlet B is provided in the middle of the refrigerant pipe 151, and the circulating water pipe 152 is provided with a third inlet E and a second outlet F at both ends.

[0037] The first electronic expansion valve 141 is connected to the refrigerant line 151 through the first inlet A, and the second electronic expansion valve 142 is connected to the refrigerant line 151 through the second inlet B; the compressor 110 is connected to the refrigerant line 151 through the first outlet C.

[0038] Evaporator 150 is coupled to the return water pipe of the indoor heating system that flows through the user terminal heat exchanger. The circulating water in the return water pipe flows through the third inlet E and the second outlet F through the circulating water pipe 152 in evaporator 150. Evaporator 150 absorbs the heat of the circulating water, thereby raising the temperature of the refrigerant in evaporator 150 and lowering the temperature of the circulating water. Then, the water in the water tank is heated by compressor 110 and condenser 120 to provide domestic hot water.

[0039] Specifically, the temperature detection module 160 includes a first temperature sensor 161, a second temperature sensor 162, a third temperature sensor 163, and a fourth temperature sensor 164.

[0040] The first temperature sensor 161 is installed at the compressor discharge end to collect the actual discharge temperature T of the compressor 110. p and the actual exhaust temperature T p Transmitted to the controller.

[0041] The second temperature sensor 162 is installed on the water tank 121 to collect the actual temperature T of the water tank 121. t and the actual temperature T t Transmitted to the controller.

[0042] The third temperature sensor 163 is installed on the compressor return gas end and is used to collect the actual return gas temperature T of the compressor 110. s and the actual return gas temperature T s Transmitted to the controller.

[0043] The fourth temperature sensor 164 is installed at the third inlet E of the circulating water pipeline 152 to collect the circulating water return temperature T. i and set the circulating water return temperature T i Transmitted to the controller.

[0044] Specifically, the pressure detection module 170 includes a high-pressure sensor 171 and a low-pressure sensor 172.

[0045] High-pressure sensor 171 is installed at the compressor discharge end to collect the pressure signal P of the high-temperature, high-pressure gaseous refrigerant discharged from compressor 110. h By combining the temperature and pressure comparison table, the condensation temperature T of the refrigerant at that pressure can be accurately obtained. l And transmit it to the controller.

[0046] Low-pressure sensor 172 is installed on the compressor return end to collect the pressure signal P of the low-temperature, low-pressure gaseous refrigerant drawn into the compressor 110. d By combining the temperature and pressure comparison table, the evaporation temperature T of the refrigerant at that pressure can be accurately obtained. z And transmit it to the controller.

[0047] Among them, exhaust superheat ΔT p The actual exhaust temperature T p With condensation temperature T l The difference between them; return gas superheat ΔT s The actual return gas temperature T s With evaporation temperature T z The difference between them.

[0048] Specifically, the switch module 180 includes a first switch 181 and a second switch 182.

[0049] The first switch 181 is a high-pressure switch, located at the compressor discharge end, used to protect the refrigeration system and compressor, preventing damage or malfunction of system components due to excessive condensing pressure.

[0050] The second switch 182 is a target-type flow switch, which is installed at the third inlet E of the circulating water pipeline 152 to detect the flow of circulating water.

[0051] Specifically, the control module 190 includes a controller (not shown), wherein the controller is electrically or communicatively connected to the compressor 110, the electronic expansion valve assembly 140, the temperature detection module 160, the pressure detection module 170, and the switch module 180.

[0052] For details, please refer to Figures 3 to 4 The controller of the heat pump system of the present invention performs adaptive control of evaporation capacity through the following method.

[0053] S10 obtains the current actual temperature T of the water tank. t The status of the target-type flow switch and the current circulating water return temperature T. i The compressor's downtime, if it satisfies: the actual water tank temperature T at the current moment... t Less than or equal to the water tank set temperature T t-set Temperature difference between start and stop ΔT qt The difference between them, the target flow switch being on, and the current circulating water return temperature T i Greater than the minimum return water temperature T i-low If the compressor has been off for more than 3 minutes, start the system.

[0054] S20 determines the current circulating water return temperature T. i Is it greater than the evaporation temperature T?z :

[0055] If the current circulating water return temperature T i > Evaporation temperature T z Control the second electronic expansion valve to open to the initial opening degree and the first electronic expansion valve to close, start the compressor, and after the compressor has been running for more than 5 minutes, execute step S30;

[0056] If the current circulating water return temperature T i ≤ Evaporation temperature T z The first electronic expansion valve is opened to its initial opening degree, the second electronic expansion valve is closed, the compressor is started, and after the compressor has been running for more than 5 minutes, step S40 is executed.

[0057] S30 obtains the current return gas superheat ΔT. s Determine the current superheat ΔT of the return gas. s Is it greater than the target superheat ΔT? s-set :

[0058] For example, the current superheat of the return gas ΔT s >Target superheat ΔT s-set This increases the opening of the second electronic expansion valve;

[0059] For example, the current superheat of the return gas ΔT s =Target superheat ΔT s-set Then the opening degree of the second electronic expansion valve remains unchanged;

[0060] For example, the current superheat of the return gas ΔT s <Target superheat ΔT s-set This reduces the opening of the second electronic expansion valve;

[0061] During this process, the opening degree of the second electronic expansion valve is continuously acquired. If the opening degree is less than or equal to the minimum allowable opening degree and is maintained for more than 10 seconds, then step S20 is executed.

[0062] S40 obtains the current return gas superheat ΔT. s Determine the current superheat ΔT of the return gas. s Is it greater than the target superheat ΔT? s-set :

[0063] For example, the current superheat of the return gas ΔT s >Target superheat ΔT s-set This increases the opening degree of the first electronic expansion valve;

[0064] For example, the current superheat of the return gas ΔT s =Target superheat ΔT s-setIf the opening of the first electronic expansion valve remains unchanged, then the opening of the first electronic expansion valve remains unchanged.

[0065] For example, the current superheat of the return gas ΔT s <Target superheat ΔT s-set This reduces the opening degree of the first electronic expansion valve.

[0066] During this process, the opening degree of the first electronic expansion valve is continuously acquired. If the opening degree is greater than or equal to the maximum allowable opening degree and is maintained for more than 10 seconds, then step S20 is executed.

[0067] Specifically, the values ​​of each parameter are shown in Table 1.

[0068]

[0069] Please see Figure 5 Furthermore, the controller of the heat pump system of the present invention also includes controlling the opening degree of the electronic expansion valve based on the exhaust superheat:

[0070] Obtain the current exhaust superheat ΔT p Determine the exhaust superheat ΔT at the current moment. p Is it greater than the allowable valve opening temperature difference ΔT? k If the current exhaust superheat ΔT is satisfied... p Greater than the allowable valve opening temperature difference ΔT k Obtain the current opening degree of the electronic expansion valve and determine whether the current opening degree of the electronic expansion valve is greater than the maximum allowable opening degree:

[0071] If the opening degree of the electronic expansion valve at the current moment equals the maximum allowable opening degree, then the electronic expansion valve will maintain its current opening degree.

[0072] If the opening degree of the electronic expansion valve at the current moment is less than the maximum allowable opening degree, the electronic expansion valve will increase the opening degree according to a specific period and a specific increment.

[0073] In other cases, the opening of the electronic expansion valve remains unchanged.

[0074] Specifically, the exhaust superheat ΔT at the current moment p Less than or equal to the allowable valve opening temperature difference ΔT k The opening degree of the electronic expansion valve is not adjusted.

[0075] Specifically, the allowable valve opening temperature difference ΔT k The value is 25℃.

[0076] Specifically, when implementing the adaptive evaporation capacity control method, the exhaust superheat ΔT is monitored synchronously in real time. p Through the aforementioned exhaust superheat ΔT pThe control method achieves macroscopic adjustment of the electronic expansion valve opening. When both control methods are required to control the electronic expansion valve opening simultaneously, the method based on exhaust superheat ΔT is preferred. p Control the opening degree of the electronic expansion valve.

[0077] The adaptive evaporation capacity heat pump system proposed in this application dynamically adjusts the evaporation area and refrigerant flow rate by real-time monitoring of the evaporator's heat load demand to adapt to different heat load requirements, thereby protecting the compressor from overheating or liquid slugging damage. Specifically, this includes determining the electronic expansion valve connected to the heat pump system based on the heat load demand, setting the initial opening, and adjusting the opening of the electronic expansion valve using parameters such as return gas superheat to control the refrigerant flow rate; the system continuously monitors the circulating water return temperature to redetermine the required electronic expansion valve, and dynamically adjusts the evaporation area and refrigerant flow rate to adapt to changes in heat load demand, ensuring safe compressor operation; simultaneously, it synchronously monitors the exhaust superheat ΔT in real time. p To prevent exhaust overheating ΔT p Excessive heat pump levels can have a series of negative effects on the system, so it is important to ensure the safe operation of the system.

[0078] This method not only improves the energy efficiency of the heat pump system, but also protects the compressor and extends the service life of the equipment through precise control of the electronic expansion valve.

[0079] The terminology used in the embodiments of this application is for the purpose of describing specific embodiments only and is not intended to limit the embodiments of this application. The singular forms "a," "described," and "the" used in the embodiments and claims of this application are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that, unless otherwise stated, "first," "second," "third," etc., are used only for distinction and not to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. When the above description relates to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of this application, those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0080] The embodiments described above merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A heat pump system with adaptive evaporation capacity, comprising a compressor, a condenser, a first electronic expansion valve and a second electronic expansion valve connected in parallel, and an evaporator with adjustable evaporation area, wherein the first electronic expansion valve controls the flow rate of refrigerant flowing through the larger evaporation area, and the second electronic expansion valve controls the flow rate of refrigerant flowing through the smaller evaporation area; further comprising a pressure detection module, a temperature detection module, a switching module, and a controller communicatively connected to the compressor, the first electronic expansion valve, the second electronic expansion valve, the pressure detection module, the temperature detection module, and the switching module, characterized in that... The controller adaptively controls the evaporation capacity of the heat pump system in the following manner: Get the current actual temperature T of the water tank. t The status of the target-type flow switch and the current circulating water return temperature T. i and the compressor's shutdown time, if it satisfies: the actual water tank temperature T at the current moment. t Less than or equal to the water tank set temperature T t-set Temperature difference ∆T between start and stop qt The difference between them, the target flow switch being on, and the current circulating water return temperature T i Greater than the minimum return water temperature T i-low If the compressor has been off for more than 3 minutes, start the system. Get the current circulating water return temperature T i If the current circulating water return temperature T i Greater than the evaporation temperature T z If the second electronic expansion valve is activated, its opening degree is obtained. If the opening degree is less than or equal to the minimum allowable opening degree and is maintained for more than 10 seconds, the second electronic expansion valve is closed and the first electronic expansion valve is activated. Otherwise, the first electronic expansion valve is activated. After the system has been running for a period of time, based on the current return gas temperature T... s With evaporation temperature T z Calculate the return gas superheat ∆T s And based on the return gas superheat ∆T s and exhaust superheat ∆T p Adjust the opening degree of the activated electronic expansion valve and continuously acquire the circulating water return temperature T at the next moment. i ; Among them, based on exhaust superheat ∆T p Controlling the opening degree of the electronic expansion valve includes: based on the actual exhaust temperature T at the current moment. p With condensation temperature T l Calculate exhaust superheat ∆T p Determine the exhaust superheat ∆T at the current moment. p Is it greater than the allowable valve opening temperature difference ∆T? k If the current exhaust superheat ∆T is satisfied... p Greater than the allowable valve opening temperature difference ∆T k Obtain the current opening degree of the electronic expansion valve and determine whether the current opening degree of the electronic expansion valve is greater than the maximum allowable opening degree: If the opening degree of the electronic expansion valve at the current moment equals the maximum allowable opening degree, then the electronic expansion valve will maintain its current opening degree. If the opening degree of the electronic expansion valve at the current moment is less than the maximum allowable opening degree, the electronic expansion valve will increase the opening degree according to a specific period and a specific increment. In other cases, the opening of the electronic expansion valve remains unchanged.

2. The heat pump system with adaptive evaporation capacity according to claim 1, characterized in that: Based on the current return gas temperature T s With evaporation temperature T z Calculate the return gas superheat ∆T s Determine the current superheat ∆T of the return gas. s With the target superheat ∆T s-set Relationship: If the current return gas superheat ∆T s Greater than the target superheat ∆T s-set This increases the opening degree of the electronic expansion valve; If the current return gas superheat ∆T s Equal to the target superheat ∆T s-set If so, the opening degree of the electronic expansion valve remains unchanged; If the current return gas superheat ∆T s Less than the target superheat ∆T s-set This reduces the opening degree of the electronic expansion valve.

3. The heat pump system with adaptive evaporation capacity according to claim 2, characterized in that: It also includes, when the first electronic expansion valve is activated, obtaining the opening degree of the first electronic expansion valve, and if its opening degree is greater than or equal to the maximum allowable opening degree and is maintained for more than 10 seconds, closing the first electronic expansion valve and activating the second electronic expansion valve.

4. The heat pump system with adaptive evaporation capacity according to claim 3, characterized in that: Water tank set temperature T t-set 55℃; Start-stop temperature difference ∆T qt The minimum return water temperature is 5℃; i-low The temperature is 7℃; the allowable valve opening temperature difference ∆T k The target temperature is 25℃; the target superheat ∆T s-set The temperature is 3℃.

5. The heat pump system with adaptive evaporation capacity according to claim 1, characterized in that: The evaporator includes a refrigerant pipeline through which the refrigerant flows and a circulating water pipeline through which the circulating water in the return water pipe of the indoor heating system flows. The evaporator is coupled to the return water pipe of the indoor heating system that flows through the user terminal heat exchanger. The circulating water in the return water pipe exchanges heat with the refrigerant in the refrigerant pipeline through the circulating water pipeline.

6. The heat pump system with adaptive evaporation capacity according to claim 5, characterized in that: It also includes a first inlet and a first outlet at both ends of the refrigerant pipeline, a second inlet in the middle of the refrigerant pipeline, and a third inlet and a second outlet at both ends of the circulating water pipeline.

7. The heat pump system with adaptive evaporation capacity according to claim 6, characterized in that: The first electronic expansion valve is connected to the refrigerant pipeline through the first inlet, and the second electronic expansion valve is connected to the refrigerant pipeline through the second inlet; the compressor is connected to the refrigerant pipeline through the first outlet, and the circulating water in the return water pipe flows through the circulating water pipeline in the evaporator through the third inlet and the second outlet.

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