A heating heat pump defrosting control method coupled with a phase change heat storage technology and a heating heat pump

Abstract

The application relates to a heating heat pump defrosting control method coupled with a phase change heat storage technology and a heating heat pump. The defrosting control method can accurately determine the starting point of defrosting through cooperative defrosting judgment based on the current time difference parameters of coil temperature, outdoor ring temperature and indoor ring temperature and the current time change rate of inlet and outlet water temperature difference based on heating water supply, thereby fundamentally avoiding system performance degradation caused by 'defrosting not being performed in the presence of frost' and energy invalid loss caused by 'defrosting being performed in the absence of frost'; the first phase change heat accumulator can be used for efficiently scheduling the heat storage in the phase change heat accumulator for defrosting, effectively reducing the influence of defrosting on heating of the heating terminal, the second phase change heat accumulator can be used for effectively reducing the influence of reverse cycle defrosting on heating of the heating terminal in the case that the heat of the first phase change heat accumulator is insufficient to complete defrosting and reverse cycle defrosting is performed, and the optimal balance between heating continuity and defrosting effectiveness is realized.

Description

Technical Field

[0001] This invention relates to the field of heating heat pump control technology, and in particular to a defrosting control method for a heating heat pump coupled with phase change thermal storage technology, and a heating heat pump thereof. Background Technology

[0002] Air source heat pumps are widely used due to their high efficiency, energy saving, and environmental friendliness. However, in winter heating conditions, when the outdoor air temperature is low and the humidity is high, frost is prone to form on the evaporator surface. Frost formation can significantly deteriorate heat exchange performance, causing a sharp drop in heating capacity or even unit shutdown. Therefore, timely defrosting is necessary to maintain the system's efficient and stable operation.

[0003] Currently, air source heat pumps often experience "false defrosting" malfunctions during actual operation: if frost is not defrosted when present, the unit's heating capacity and overall performance will be severely limited; if defrosting occurs when there is no frost, unnecessary heat loss and increased energy consumption will result. Therefore, accurately determining the start and end points of defrosting is crucial for optimizing defrosting control; effective defrosting control, based on reasonable defrosting start and end times, can ensure stable system operation, reduce energy consumption, and maintain indoor thermal comfort levels throughout the defrosting cycle.

[0004] In heat pump defrosting technology, reverse cycle defrosting is currently the most widely used method. Its principle is to switch the refrigerant flow direction by switching the four-way reversing valve, thus switching the system from heating mode to cooling mode. At this time, the high-temperature, high-pressure refrigerant gas discharged from the compressor first enters the outdoor heat exchanger to condense and release heat, achieving defrosting; then it passes through the capillary tube for throttling and pressure reduction, entering the indoor heat exchanger for evaporation and heat absorption; finally, it returns to the compressor through the gas-liquid separator 104, completing the cycle. This method is technically mature and has low cost, hence its widespread adoption.

[0005] However, reverse circulation defrosting still has several problems in practical applications, mainly including: long defrosting cycles, defrosting water retention, insufficient defrosting heat source, and a significant drop in indoor temperature leading to reduced thermal comfort. In addition, this method is prone to generating significant noise during the switching of the four-way reversing valve, and may also experience "oil run-in" when the system switches between high and low pressure, affecting operational stability and reliability. Summary of the Invention

[0006] Therefore, the purpose of this invention is to provide a defrosting control method for heating heat pumps coupled with phase change thermal storage technology. By optimizing the defrosting control logic, the starting and ending points of defrosting are accurately determined. Combined with phase change thermal storage technology, the method enables the switching between compressor exhaust heat storage defrosting mode and ordinary reverse circulation defrosting mode. This ensures stable system operation, reduces energy consumption, and maintains indoor thermal comfort levels during the defrosting cycle.

[0007] A defrosting control method for a heating heat pump coupled with phase change thermal storage technology is disclosed. The heating heat pump includes a compressor, a four-way valve, a first phase change thermal accumulator, a water-based heat exchanger, a solenoid valve, an electronic expansion valve, an air source heat exchanger, and a one-way valve disposed between the first phase change thermal accumulator and the electronic expansion valve, all connected sequentially via refrigerant piping. The defrosting control method for the heating heat pump includes the following steps:

[0008] S1: In heating mode, obtain the current outdoor ambient temperature. Indoor ambient temperature Coil temperature Calculate the temperature difference parameter at the current moment. and temperature difference parameter change value ; Obtain the outlet water temperature Return water temperature Calculate the inlet and outlet water temperature difference at the current moment. and the rate of change of inlet and outlet water temperature difference : If the following conditions are met: temperature difference parameter change value ≥Temperature difference parameter change threshold And the rate of change of inlet and outlet water temperature difference ≤ Threshold for rate of change of inlet and outlet water temperature Control the heating heat pump to enter defrost mode; Among them, the temperature difference parameter at the current moment satisfy: ; Current temperature difference parameter change value satisfy: ; in, , This indicates the outdoor ambient temperature at the previous moment. This indicates the indoor ambient temperature at the previous moment. This indicates the coil temperature at the previous moment.

[0009] Furthermore, the defrosting mode is controlled as follows: S2: Obtain the current heat storage temperature of the first phase change heat accumulator. ; If the following is satisfied: current heat storage temperature ≤Minimum allowable temperature for phase change heat storage Control the heating heat pump to enter phase change heat storage defrosting mode; In other cases, control the heating heat pump to enter reverse circulation defrosting mode.

[0010] Furthermore, the phase change heat storage defrosting mode is specifically as follows: The working ports D and E of the four-way valve are connected, the check valve is connected, and the solenoid valve is closed, so that the refrigerant circulation of the heating heat pump is compressor, four-way valve, air source heat exchanger, electronic expansion valve, check valve, first phase change heat accumulator, four-way valve, and compressor.

[0011] Furthermore, the minimum allowable temperature for phase change heat storage... satisfy: ; In the formula, This indicates the phase change temperature of the phase change heat storage material in the first phase change heat storage unit. This indicates the set allowable temperature fluctuation value.

[0012] Furthermore, the reverse-cycle defrosting mode is specifically as follows: The working ports D and E of the four-way valve are connected, the check valve is closed, and the solenoid valve is connected, so that the refrigerant circulation of the heating heat pump is through the compressor, the four-way valve, the air source heat exchanger, the electronic expansion valve, the solenoid valve, the water heat exchanger, the first phase change heat accumulator, the four-way valve, and the compressor.

[0013] Furthermore, the reverse cycle defrosting mode also includes controlling the heat release of the second phase change accumulator; The second phase change heat accumulator is installed on the outlet pipe of the water working medium heat exchanger.

[0014] Furthermore, it also includes step S3: In defrost mode, obtain the current temperature of the defrost coil. and the defrosting operation time t` of the compressor; If the following condition is met: the current defrosting coil temperature ≥Defrosting coil temperature reaches set value And the defrosting operation time t` is greater than or equal to the minimum operation time t of the compressor to exit defrosting. min-2 Control the heating heat pump to exit defrost mode and enter heating mode.

[0015] Furthermore, the current inlet and outlet water temperature difference satisfy: ; The rate of change of inlet and outlet water temperature difference at the current moment satisfy: ; in, , This indicates the temperature difference between the inlet and outlet water at the previous moment. This indicates the water temperature at the previous moment. This indicates the return water temperature at the previous moment.

[0016] Furthermore, it also includes determining the compressor's heating time, specifically: Obtain the heating time t of the compressor since it exited the previous defrost mode: If the following condition is met: Heating time t ≥ Minimum operating time t of compressor entering defrost mode min-1 Then the heating heat pump will be controlled to enter defrost mode. That is, simultaneously satisfying the change value of the temperature difference parameter ≥Temperature difference parameter change threshold And the rate of change of inlet and outlet water temperature difference ≤ Threshold for rate of change of inlet and outlet water temperature And the heating time t ≥ the minimum operating time t of the compressor to enter defrost mode. min-1 Control the heating heat pump to enter defrost mode.

[0017] Compared to existing technologies, the defrosting control method for heating heat pumps coupled with phase change thermal storage technology proposed in this invention can accurately determine the starting point of defrosting by using the current temperature difference parameters based on coil temperature, outdoor ambient temperature, and indoor ambient temperature, and the rate of change of the inlet and outlet water temperature difference based on the current temperature difference of the heating water supply. This fundamentally avoids system performance degradation caused by "not defrosting when there is frost" and ineffective energy loss caused by "defrosting when there is no frost". The first phase change thermal accumulator can efficiently dispatch the heat stored in the phase change thermal accumulator for defrosting, effectively reducing the impact of defrosting on the heating terminal. The second phase change thermal accumulator can effectively reduce the impact of reverse circulation defrosting on the heating terminal when the heat of the first phase change thermal accumulator is insufficient to complete defrosting and reverse circulation defrosting is performed. Overall, this invention significantly reduces the disturbance of the indoor thermal environment during the defrosting process, achieves an optimized balance between heating continuity and defrosting effectiveness, and ensures stable system operation, reduces energy consumption, and maintains indoor thermal comfort levels during the defrosting cycle.

[0018] Meanwhile, the present invention provides a heating heat pump, comprising a compressor, a four-way valve, a first phase change heat accumulator, a water-based heat exchanger, a solenoid valve, an electronic expansion valve, an air source heat exchanger, and a one-way valve disposed between the first phase change heat accumulator and the electronic expansion valve, which are connected in sequence through refrigerant pipelines. It also includes a second phase change heat accumulator disposed on the outlet pipeline of the water-based heat exchanger, a temperature detection unit, and a controller electrically and / or communicatively connected to the compressor, the four-way valve, the solenoid valve, the first phase change heat accumulator, the second phase change heat accumulator, and the temperature detection unit. The controller implements the defrosting control method for the heating heat pump coupled with phase change heat storage technology as described in any of the above embodiments.

[0019] Compared with the prior art, the beneficial effects of the heating heat pump provided by the present invention are the same as those of the above-mentioned heating heat pump defrosting control method with coupled phase change thermal storage technology, and will not be repeated here. Attached Figure Description

[0020] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of a heating heat pump using the coupled phase change thermal energy storage technology of the present invention. Figure 2 This is a flowchart of the defrosting control method for a heating heat pump using the coupled phase change thermal energy storage technology of the present invention. Figure 3 This is a schematic diagram of the phase change thermal storage defrosting mode of the coupled phase change thermal storage technology of the present invention; Figure 4 This is a schematic diagram of the reverse circulation defrosting mode of the coupled phase change thermal storage technology of the present invention. Detailed Implementation

[0022] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings of the embodiments of the present invention. The described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0023] Please see Figure 1 The heating heat pump with coupled phase change heat storage technology proposed in this invention includes a compressor 1, a four-way valve 2, a first phase change heat accumulator 3, a water-based heat exchanger 4, a solenoid valve 5, an electronic expansion valve 6, an air source heat exchanger 7, and a one-way valve 8 disposed between the first phase change heat accumulator 3 and the electronic expansion valve 6, which are connected in sequence through refrigerant pipelines; it also includes a second phase change heat accumulator 9 disposed on the outlet pipeline of the water-based heat exchanger 4, a temperature detection unit, and a controller that is electrically and / or communicatively connected to the compressor 1, the four-way valve 2, the solenoid valve 5, the first phase change heat accumulator 3, the second phase change heat accumulator 9, and the temperature detection unit.

[0024] The compressor 1 includes an exhaust port A and a return port B. Further, an oil separator 102 is connected between the compressor 1 exhaust port A and the four-way valve 2. Further, a gas-liquid separator 104 is connected between the compressor 1 return port B and the four-way valve 2.

[0025] The four-way valve 2 includes a working port D, a working port E, a working port S, and a working port C. The working port D is connected to the exhaust port A of the compressor 1 through the oil separator 102, the working port E is connected to a refrigerant port of the air source heat exchanger 7, the working port S is connected to the return port B of the compressor 1 through the gas-liquid separator 104, and the working port C is connected to a refrigerant port of the water working fluid heat exchanger 4.

[0026] The water-based heat exchanger 4 has one refrigerant port connected to the first phase change heat storage unit 3, and the other refrigerant port connected to the electronic expansion valve 6; its water pipe is connected to the heating terminal water pipe. The water-based heat exchanger 4 is installed indoors and is a shell-and-tube heat exchanger, a plate heat exchanger, or a high-efficiency tank heat exchanger. Further, a water pump 402 is installed on the return water pipe of the water-based heat exchanger 4, and a water tank 404 is installed on the outlet water pipe of the water-based heat exchanger 4. The heating terminal includes a distributor, a collector, and a heating device installed between the distributor and the collector. The heating device is not limited to underfloor heating pipes or radiators. The water flow direction of the water-based heat exchanger 4 is: collector → water pump 402 → water-based heat exchanger 4 → water tank 404 → second phase change heat storage unit 9 → distributor → underfloor heating pipes / radiators → collector.

[0027] The air source heat exchanger 7 has one refrigerant port connected to the electronic expansion valve 3 and the other refrigerant port connected to the four-way valve 2. The air source heat exchanger 7 is installed outdoors and is a finned heat exchanger. Furthermore, a liquid valve 602 is installed between the air source heat exchanger 7 and the electronic expansion valve 3, and a gas valve 604 is installed between the air source heat exchanger 7 and the four-way valve 2.

[0028] The second phase change heat storage device 9 is installed between the outlet pipe of the water working medium heat exchanger 4 and the heating terminal.

[0029] The temperature detection unit includes a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor, and a fifth temperature sensor.

[0030] The first temperature sensor is installed outdoors and is used to measure the outdoor ambient temperature. And real-time outdoor ambient temperature Transmitted to the controller.

[0031] The second temperature sensor, installed outdoors at the heating terminal, is used to measure the indoor ambient temperature. And monitor the indoor ambient temperature in real time. Transmitted to the controller.

[0032] The third temperature sensor is installed on the coil of the air source heat exchanger and is used to measure the coil temperature. And monitor the coil temperature in real time. Transmitted to the controller.

[0033] The fourth temperature sensor is installed at the outlet of the water pipe of the water heat exchanger and is used to measure the outlet water temperature. and the outlet water temperature is displayed in real time. Transmitted to the controller.

[0034] The fifth temperature sensor is installed at the return water inlet of the water pipe in the water heat exchanger and is used to measure the return water temperature. and real-time return water temperature Transmitted to the controller.

[0035] The controller acquires data transmitted from the temperature detection unit, compressor, and first phase change heat storage unit, and controls the heat release of the four-way valve, electronic expansion valve, first phase change heat storage unit, and second phase change heat storage unit according to the defrosting control method of heating heat pump with coupled phase change heat storage technology.

[0036] During the operation of a heating heat pump system, when frost forms on the surface of the air source heat exchanger fins and accumulates to a certain thickness, the system's heating capacity and operational efficiency will significantly decrease. The additional thermal resistance formed by the frost severely hinders effective heat exchange between the air source heat exchanger fins and the outdoor environment, leading to a sharp drop in the heat exchanger's capacity. At this time, the process of releasing cold energy from the air source heat exchanger coil to the outside is obstructed, the coil temperature drops rapidly, and the temperature difference between the coil and the environment abnormally increases.

[0037] Based on the aforementioned physical phenomena and thermodynamic principles, this application establishes the coil temperature change rate of the air source heat exchanger as the primary criterion for defrosting initiation. Simultaneously, considering that the heating terminal of the heating heat pump system adopts floor radiant heating, this heating method, due to its high thermal inertia and slow heat transfer response, results in minimal fluctuations in indoor ambient temperature per unit time, exhibiting significant stability. Therefore, this stable indoor thermal environment parameter is incorporated into the defrosting initiation criterion to improve the accuracy and robustness of defrosting judgment.

[0038] Please see Figure 2 The controller implements defrosting control of the heating heat pump coupled with phase change thermal storage technology in the following manner, specifically including the following steps.

[0039] S1: In heating mode, obtain the current outdoor ambient temperature. Indoor ambient temperature Coil temperature Calculate the temperature difference parameter at the current moment. and temperature difference parameter change value ; Obtain the outlet water temperature Return water temperature Calculate the inlet and outlet water temperature difference at the current moment. and the rate of change of inlet and outlet water temperature difference : If the following conditions are met: temperature difference parameter change value ≥Temperature difference parameter change threshold And the rate of change of inlet and outlet water temperature difference ≤ Threshold for rate of change of inlet and outlet water temperature If so, proceed to step S2 to control the heating heat pump to enter defrost mode.

[0040] The temperature difference parameter at the current moment satisfy: ; In the formula, This indicates the current outdoor ambient temperature. This indicates the current indoor ambient temperature. This indicates the current coil temperature.

[0041] The change value of the temperature difference parameter at the current moment satisfy: ; in This represents the change in temperature difference parameter at the previous moment. ; In the formula, This indicates the outdoor ambient temperature at the previous moment. This indicates the indoor ambient temperature at the previous moment. This indicates the coil temperature at the previous moment.

[0042] When frost buildup significantly impacts the heat exchange performance of the air source heat exchanger, the coil temperature will drop dramatically, while the outdoor and indoor ambient temperatures remain relatively stable, resulting in a change in the current temperature difference parameter. Increase rapidly; if and The difference exceeds the preset threshold for temperature difference parameter change. Air source heat exchanger fins have a very high probability of frosting, and the frosting layer is quite thick. Therefore, this application will use the current temperature difference parameter... This serves as the first core criterion for determining system frost formation.

[0043] The current inlet and outlet water temperature difference satisfy: ; In the formula, This indicates the current water temperature. This indicates the current return water temperature.

[0044] The rate of change of inlet and outlet water temperature difference at the current moment satisfy: ; In the formula, This indicates the current temperature difference between the inlet and outlet water. This indicates the temperature difference between the inlet and outlet water at the previous moment.

[0045] Meanwhile, the outlet and return water temperatures of the water-based heat exchanger's piping are also significantly affected by the frosting process on the air-source heat exchanger fins. When frosting leads to a decrease in the system's heating capacity and energy efficiency, the temperature difference between the outlet and return water will show a significant narrowing trend, reducing the rate of change of the inlet and outlet water temperature difference. It possesses clear physical directionality and measurability. Therefore, this application will use the rate of change of inlet and outlet water temperature difference. This serves as the second core criterion for determining system frost formation.

[0046] To further enhance the robustness of the defrosting control system and prevent false triggering due to sudden anomalies such as sensor malfunction or signal interference, the parameter determination for controlling the heating heat pump to enter defrosting mode also includes the determination of the compressor's heating time. Specifically: Obtain the heating time t of the compressor since it exited the previous defrost mode: If the following condition is met: Heating time t ≥ Minimum operating time t of compressor entering defrost mode min-1 Then the heating heat pump will be controlled to enter defrost mode.

[0047] That is, simultaneously satisfying the change value of the temperature difference parameter ≥Temperature difference parameter change threshold And the rate of change of inlet and outlet water temperature difference ≤ Threshold for rate of change of inlet and outlet water temperature And the heating time t ≥ the minimum operating time t of the compressor to enter defrost mode. min-1 Control the heating heat pump to enter defrost mode.

[0048] S2: Obtain the current heat storage temperature of the first phase change heat accumulator. ; If the following is satisfied: current heat storage temperature ≤Minimum allowable temperature for phase change heat storage Control the heating heat pump to enter phase change heat storage defrosting mode; In other cases, control the heating heat pump to enter reverse circulation defrosting mode.

[0049] The minimum allowable temperature for phase change heat storage satisfy: ; In the formula, This indicates the phase change temperature of the phase change heat storage material in the first phase change heat storage unit. This indicates the set allowable temperature fluctuation value, such as 2℃, 3℃, etc.

[0050] Please see Figure 3 The phase change heat storage defrosting mode is as follows: The working ports D and E of the four-way valve are connected, the check valve is connected, the solenoid valve is closed, and the gas valve and liquid valve are connected, so that the refrigerant circulation of the heating heat pump is as follows: compressor → oil separator 102 → four-way valve → air source heat exchanger → electronic expansion valve → check valve → first phase change heat accumulator → four-way valve → gas-liquid separator 104 → compressor.

[0051] Please see Figure 4 The reverse-cycle defrosting mode is as follows: The working ports D and E of the four-way valve are connected, the check valve is closed, the solenoid valve is connected, and the gas valve and liquid valve are connected, so that the refrigerant circulation of the heating heat pump is as follows: compressor → oil separator 102 → four-way valve → air source heat exchanger → electronic expansion valve → solenoid valve → water working medium heat exchanger → first phase change heat accumulator → four-way valve → gas-liquid separator 104 → compressor; at the same time, the second phase change heat accumulator is controlled to release heat.

[0052] It works in conjunction with a second phase change heat accumulator installed on the outlet pipe of the water-based heat exchanger. Even during reverse circulation defrosting, the water entering the heating terminals is still heated, reducing the impact of reverse circulation defrosting on heating and improving the user experience at the heating terminals.

[0053] To reduce the impact of air source heat pump fin defrosting on the temperature fluctuations of the heating terminal, this invention prioritizes using the heat from the first phase change heat accumulator for defrosting. When the required defrosting heat is high and the heat stored in the first phase change heat accumulator is insufficient, the system switches to reverse circulation for supplementary defrosting, while simultaneously activating the second phase change heat accumulator to heat the outlet water of the water-based heat exchanger.

[0054] S3: In defrost mode, obtain the current temperature of the defrost coil. and the defrosting operation time t` of the compressor; If the following condition is met: the current defrosting coil temperature ≥Defrosting coil temperature reaches set value And the defrosting operation time t` is greater than or equal to the minimum operation time t of the compressor to exit defrosting. min-2 Control the heating heat pump to exit defrost mode and enter heating mode.

[0055] Compared to existing technologies, the defrosting control method for heating heat pumps coupled with phase change thermal storage technology proposed in this invention can accurately determine the starting point of defrosting by using the current temperature difference parameters based on coil temperature, outdoor ambient temperature, and indoor ambient temperature, and the rate of change of the inlet and outlet water temperature difference based on the current temperature difference of the heating water supply. This fundamentally avoids system performance degradation caused by "not defrosting when there is frost" and ineffective energy loss caused by "defrosting when there is no frost". The first phase change thermal accumulator can efficiently dispatch the heat stored in the phase change thermal accumulator for defrosting, effectively reducing the impact of defrosting on the heating terminal. The second phase change thermal accumulator can effectively reduce the impact of reverse circulation defrosting on the heating terminal when the heat of the first phase change thermal accumulator is insufficient to complete defrosting and reverse circulation defrosting is performed. Overall, this invention significantly reduces the disturbance of the indoor thermal environment during the defrosting process, achieves an optimized balance between heating continuity and defrosting effectiveness, and ensures stable system operation, reduces energy consumption, and maintains indoor thermal comfort levels during the defrosting cycle.

[0056] The aforementioned defrosting control method for heating heat pumps using coupled phase change thermal energy storage technology is stored in an electronic device and executed by this electronic device to achieve defrosting control of the heating heat pump. The electronic device includes, but is not limited to, a memory, processor, and network interface that can be interconnected via a system bus.

[0057] The memory includes at least one type of readable storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. The memory can be an internal storage unit of the electronic device, such as the hard disk or RAM of the electronic device. The memory can also be an external storage device of the electronic device, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc. The memory may also include both internal storage units and external storage devices of the electronic device.

[0058] The processor can be a central processing unit (CPU), controller, microcontroller, microprocessor, or other data processing chip. This processor is typically used to control the overall operation of the electronic device, such as performing control and processing related to data interaction or communication with the electronic device. The processor is used to run program code stored in the memory or process data, for example, to run the defrosting control method for a heating heat pump using the coupled phase change thermal storage technology.

[0059] The network interface may include a wireless network interface or a wired network interface, which is typically used to establish communication connections between the electronic device and other electronic devices. For example, the network interface is used to connect the electronic device to an external data platform via a network, establishing a data transmission channel and communication connection between the electronic device and the external data platform. The network may be an intranet, the Internet, Global System for Mobile communication (GSM), Wideband Code Division Multiple Access (WCDMA), 4G network, 5G network, Bluetooth, Wi-Fi, or other wireless or wired networks.

[0060] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0061] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0062] The embodiments described above are merely examples of several implementations 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 defrosting control method for a heating heat pump coupled with phase change thermal storage technology, characterized in that, This method is applicable to heating heat pumps, which include a compressor, a four-way valve, a first phase change heat accumulator, a water-based heat exchanger, a solenoid valve, an electronic expansion valve, an air source heat exchanger, and a one-way valve located between the first phase change heat accumulator and the electronic expansion valve, all connected sequentially via refrigerant piping. The defrosting control method for the heating heat pump includes the following steps: S1: In heating mode, obtain the current outdoor ambient temperature. Indoor ambient temperature Coil temperature Calculate the temperature difference parameter at the current moment. and temperature difference parameter change value ; Obtain the outlet water temperature Return water temperature Calculate the inlet and outlet water temperature difference at the current moment. and the rate of change of inlet and outlet water temperature difference : If the following conditions are met: temperature difference parameter change value ≥Temperature difference parameter change threshold And the rate of change of inlet and outlet water temperature difference ≤ Threshold for rate of change of inlet and outlet water temperature Control the heating heat pump to enter defrost mode; Among them, the temperature difference parameter at the current moment satisfy: ； Current temperature difference parameter change value satisfy: ； in, , This indicates the outdoor ambient temperature at the previous moment. This indicates the indoor ambient temperature at the previous moment. This indicates the coil temperature at the previous moment.

2. The defrosting control method for heating heat pumps using coupled phase change thermal storage technology according to claim 1, characterized in that, The defrosting mode is controlled as follows: S2: Obtain the current heat storage temperature of the first phase change heat accumulator. ; If the following is satisfied: current heat storage temperature ≤Minimum allowable temperature for phase change heat storage Control the heating heat pump to enter phase change heat storage defrosting mode; In other cases, control the heating heat pump to enter reverse circulation defrosting mode.

3. The defrosting control method for heating heat pumps using coupled phase change thermal storage technology according to claim 2, characterized in that, The phase change thermal storage defrosting mode is as follows: The working ports D and E of the four-way valve are connected, the check valve is connected, and the solenoid valve is closed, so that the refrigerant circulation of the heating heat pump is compressor, four-way valve, air source heat exchanger, electronic expansion valve, check valve, first phase change heat accumulator, four-way valve, and compressor.

4. The defrosting control method for heating heat pumps using coupled phase change thermal storage technology according to claim 2, characterized in that, The minimum allowable temperature for phase change heat storage satisfy: ； In the formula, This indicates the phase change temperature of the phase change heat storage material in the first phase change heat storage unit. This indicates the set allowable temperature fluctuation value.

5. The defrosting control method for heating heat pumps using coupled phase change thermal storage technology according to claim 2, characterized in that, The reverse-cycle defrosting mode is as follows: The working ports D and E of the four-way valve are connected, the check valve is closed, and the solenoid valve is connected, so that the refrigerant circulation of the heating heat pump is through the compressor, the four-way valve, the air source heat exchanger, the electronic expansion valve, the solenoid valve, the water heat exchanger, the first phase change heat accumulator, the four-way valve, and the compressor.

6. The defrosting control method for heating heat pumps using coupled phase change thermal storage technology according to claim 5, characterized in that, The reverse cycle defrosting mode also includes controlling the heat release of the second phase change heat accumulator; The second phase change heat accumulator is installed on the outlet pipe of the water working medium heat exchanger.

7. The defrosting control method for heating heat pumps using coupled phase change thermal storage technology according to claim 2, characterized in that, It also includes step S3: In defrost mode, obtain the current temperature of the defrost coil. and the defrosting operation time t` of the compressor; If the following condition is met: the current defrosting coil temperature ≥Defrosting coil temperature reaches set value And the defrosting operation time t` is greater than or equal to the minimum operation time t of the compressor to exit defrosting. min-2 Control the heating heat pump to exit defrost mode and enter heating mode.

8. The defrosting control method for heating heat pumps using coupled phase change thermal storage technology according to claim 1, characterized in that, The current inlet and outlet water temperature difference satisfy: ； The rate of change of inlet and outlet water temperature difference at the current moment satisfy: ； in, , This indicates the temperature difference between the inlet and outlet water at the previous moment. This indicates the water temperature at the previous moment. This indicates the return water temperature at the previous moment.

9. The defrosting control method for heating heat pumps using coupled phase change thermal storage technology according to claim 1, characterized in that, It also includes determining the compressor's heating time, specifically: Obtain the heating time t of the compressor since it exited the previous defrost mode: If the following condition is met: Heating time t ≥ Minimum operating time t of compressor entering defrost mode min-1 Then the heating heat pump will be controlled to enter defrost mode. That is, simultaneously satisfying the change value of the temperature difference parameter ≥Temperature difference parameter change threshold And the rate of change of inlet and outlet water temperature difference ≤ Threshold for rate of change of inlet and outlet water temperature And the heating time t ≥ the minimum operating time t of the compressor to enter defrost mode. min-1 Control the heating heat pump to enter defrost mode.

10. A heating heat pump, characterized in that, The system includes a compressor, a four-way valve, a first phase change heat accumulator, a water-based heat exchanger, a solenoid valve, an electronic expansion valve, an air-source heat exchanger, and a one-way valve located between the first phase change heat accumulator and the electronic expansion valve, all connected sequentially via refrigerant piping. It also includes a second phase change heat accumulator located on the outlet pipe of the water-based heat exchanger, a temperature detection unit, and a controller electrically and / or communicatively connected to the compressor, the four-way valve, the solenoid valve, the first phase change heat accumulator, the second phase change heat accumulator, and the temperature detection unit. The controller implements the defrosting control method for heating heat pumps coupled with phase change heat storage technology as described in any one of claims 1 to 9.

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