Method for realizing multi-energy complementary heat pump cold and heat dual storage based on light storage direct flexible

Abstract

The application provides an implementation method of a multi-energy complementary heat pump cold-heat dual storage based on "light storage direct flexibility", which comprises a heat pump subsystem, a first jet augmenting enthalpy subsystem, a second jet augmenting enthalpy subsystem, an energy storage subsystem, a photovoltaic power generation subsystem and a mains power system. The implementation method adopts a power supply mode of "AC mains power + photovoltaic direct current" dual power input and photovoltaic priority, realizes maximum power saving, and realizes refrigeration or heating according to instructions. According to actual load demand, the corresponding jet augmenting enthalpy subsystem is selected. In summer, cold water storage is used to reduce the condensing temperature of the unit, improve the EER and refrigeration effect; in heating, hot water storage is used as the external heat source of the second active jet augmenting enthalpy, to improve the COP and heating capacity of the heat pump, solve the technical bottleneck problem that the heat pump cannot be applied in extremely low temperature environment, and release the stored cold and heat sources when the load is high, to improve the EER and the heating performance coefficient of the heat pump.

Description

Technical Field

[0001] This invention relates to the field of heat pump technology, and more specifically, to a method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" energy transfer. Background Technology

[0002] Photovoltaics, Energy Storage, Direct Current and Flexibility (PEDF) refers to a new type of building energy system that integrates photovoltaic and other renewable energy sources for power generation, energy storage, DC power distribution, and flexible energy use to meet the needs of "dual carbon" targets. It is a crucial pathway for the building sector to address the significant demands for "carbon peaking and carbon neutrality" and achieve technological breakthroughs. However, existing heating sources primarily rely on coal-fired boilers and natural gas, which cannot be integrated with PEDF buildings that combine photovoltaic power generation, energy storage, DC power distribution, and flexible energy use, thus hindering the implementation of "dual carbon" targets in the building sector.

[0003] Research on "photovoltaic-storage-direct-flexible" heat pump systems primarily focuses on the performance of solar photovoltaic / solar thermal heat pumps and technical measures to improve energy efficiency. Solar heat pumps have evolved through two stages: solar thermal and photovoltaic. The former mainly includes heat pump-assisted solar water heaters and solar-assisted heat pumps. In heat pump-assisted solar water heaters, the heat pump system and the solar collector system are independent, with the heat pump system serving only as an auxiliary heat source when the solar collector system cannot meet the heating demand. In solar-assisted heat pumps, the solar absorber panels are used as evaporators to absorb solar energy, increase the evaporation temperature, and thus improve heating capacity and energy efficiency. From an application perspective, these include direct expansion, indirect expansion, and hybrid types, offering significant energy savings. However, these systems cannot be used for cooling; they only provide heating and cannot achieve dual cold / heat storage. To achieve cooling, the system needs to be designed with two evaporators, one of which is a finned evaporator for cooling. For photovoltaic heat pumps, solar photovoltaic panels generate electricity to drive the heat pump unit.

[0004] Photovoltaic / solar thermal air conditioning reduces energy consumption, but the dispersed and unstable nature of solar energy leads to low utilization rates and difficulty in matching with heat pump systems. Jet enthalpy enhancement technology, due to its simple structure and low added cost, has been commercialized.

[0005] Currently, the vapor injection enthalpy enhancement technology used in heat pumps is based on heat exchange with the refrigerant within the system. It improves heat pump performance by increasing subcooling to absorb more air energy and increasing compression work. Vapor injection enthalpy enhancement methods include liquid injection, gas injection, and two-phase injection. From the perspective of vapor injection enthalpy enhancement devices, these include economizer injection and flash tank injection.

[0006] Regarding liquid injection, research suggests that its effect on improving heat pump performance is almost negligible, but it can achieve temperature control, reduce compressor exhaust temperature, expand the compressor's applicable range, and ensure the safe operation of the heat pump in low-temperature environments.

[0007] While injecting gas into the economizer and flash tank can improve heat pump performance, the improvement is limited, especially in terms of energy efficiency. At even lower ambient temperatures, such as below -25°C, heating performance is difficult to guarantee, and the heat pump may even become unusable, even with vapor injection enthalpy enhancement.

[0008] To address the above issues, this invention proposes a two-stage jet enthalpy-enhancing heat pump based on a multi-energy complementary system of "photovoltaic-storage-direct-flexible" technology, achieving dual cold and heat storage. This technical solution contributes significantly to promoting the implementation of "carbon peaking and carbon neutrality." Summary of the Invention

[0009] The problem solved by this invention is to overcome at least one defect in the prior art and provide a method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic storage, direct current and flexible energy storage". By designing a self-sufficient energy storage device with dual cooling and heating storage in the system, the cooling efficiency ratio and heating performance of the heat pump are improved, and the power saving effect is maximized.

[0010] To address the aforementioned problems, this invention provides a method for implementing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" energy transfer. The heat pump includes a heat pump subsystem comprising a compressor, an oil separator, a four-way valve, an outdoor heat exchanger, a main electronic expansion valve, a liquid storage tank, a liquid pipe shut-off valve, a first branch pipe, a second branch pipe, a gas pipe shut-off valve, a gas-liquid separator, a first electronic expansion valve, a first solenoid valve, a heat exchanger, and a first water pump. The compressor outlet is connected to the inlet of the four-way valve via the oil separator, and the first outlet of the four-way valve is connected to one end of the outdoor heat exchanger. The other end of the outdoor heat exchanger is connected to one end of the liquid storage tank via the main electronic expansion valve. The other end of the liquid storage tank is connected to the first inlet of the heat exchanger via the liquid pipe shut-off valve, the first branch pipe, and the first electronic expansion valve. The first outlet of the heat exchanger is connected to the second inlet of the four-way valve via the solenoid valve, the second branch pipe, and the gas-liquid shut-off valve. The second outlet of the four-way valve is connected to the oil return port of the compressor via the gas-liquid separator. The heat pump also includes a first-stage vapor injection enthalpy enhancement subsystem, a second-stage vapor injection enthalpy enhancement subsystem, an energy storage subsystem, and a power supply system.

[0011] The energy storage subsystem includes an energy storage tank, a second electronic expansion valve, a second solenoid valve, and a third water pump. One end of the second electronic expansion valve is connected to the first branch pipe, and the other end is connected to the energy storage tank. One end of the second solenoid valve is connected to the energy storage tank, and the other end is connected to the second branch pipe. The third water pump is connected between the outdoor heat exchanger and the energy storage tank.

[0012] The first-stage jet enthalpy enhancement subsystem includes a first subcooled electronic expansion valve, a first economizer, and a first injection pipe. The first inlet of the first economizer is connected to the outlet of the liquid storage tank, the first outlet of the first economizer is connected to the liquid pipe shut-off valve, and the first outlet of the first economizer is connected to the compressor via the first injection pipe. One end of the first subcooled electronic expansion valve is connected to the second outlet of the first economizer, and the other end is connected to the second inlet of the first economizer.

[0013] The secondary jet enthalpy enhancement subsystem includes a second subcooled electronic expansion valve, a second economizer, a second water pump, and a second injection pipe. One end of the second subcooled electronic expansion valve is connected to one end of the liquid storage tank, and the other end is connected to the first inlet of the second economizer. The first outlet of the second economizer is connected to the compressor via the second injection pipe. The second outlet and the second outlet of the second economizer are both connected to the energy storage tank.

[0014] The power supply system includes a photovoltaic power generation system and a mains power system;

[0015] The heat pump operates in two modes: cooling and heating. The specific implementation methods are as follows:

[0016] a: When the unit is turned on, it operates according to the relevant instructions received by the wired controller. The wired controller is electrically connected to the heat pump controller.

[0017] b: When the unit receives a cooling command and starts operating, the controller determines the load source. When there is no cooling load, the heat pump subsystem operates for cooling, and the chilled water produced by the heat exchanger can be stored in the energy storage tank. When there is a cooling load, the heat pump subsystem operates for cooling, and the chilled water produced by the heat exchanger is delivered to the room terminal. When the cooling load is high, while operating for cooling, the third water pump is used to deliver the chilled water in the energy storage tank to the outdoor heat exchanger.

[0018] When the unit receives a heating command and starts operating, the controller determines the load source. When there is no heat load or the heat load is low, the heat pump subsystem operates to provide heating, and the hot water can be stored in the energy storage tank. During heating, the first-stage vapor injection enthalpy enhancement subsystem is activated. The refrigerant passing through the liquid pipe shut-off valve, a portion of the refrigerant is throttled by the subcooled electronic expansion valve and enters the first economizer to exchange heat with the refrigerant in the main circulation loop in the first economizer. When the heat load is high, the heat pump subsystem operates to provide heating, and the second-stage vapor injection enthalpy enhancement subsystem is activated simultaneously. The second water pump can be used to transport the hot water in the energy storage tank to the second economizer to exchange heat with the injected refrigerant, converting the low-grade heat source heat into heating capacity through vapor injection enthalpy enhancement.

[0019] During operation in either cooling or heating mode, when the photovoltaic power generation is higher than the machine's operating power, the electricity required for the heat pump to operate is supplied by the photovoltaic power generation; when the photovoltaic power generation is lower than the machine's operating power, the electricity required for the heat pump to operate is supplied by the photovoltaic power generation, supplemented by the mains power system.

[0020] The advantages of this invention compared to the prior art are:

[0021] This invention belongs to the field of heat pump systems. It designs a two-stage vapor injection enthalpy-enhancing air source heat pump system driven by photovoltaic power generation. It features a dual power input of "photovoltaic DC + AC mains power," with photovoltaic power as the priority and mains power as a supplement, achieving maximum energy savings. To improve the heat pump's cooling energy efficiency ratio (EER) and heating coefficient of performance (COP), and to address the technical bottlenecks of poor unit performance and applicability in harsh environments, a self-sufficient energy storage device with dual cold and heat storage is designed within the system. During summer cooling, the stored chilled water is used to lower the unit's condensing temperature, improving EER and cooling effect. During heating, the stored hot water is used to generate heat from the external heat source for the secondary active vapor injection enthalpy enhancement, improving the heat pump's COP and heating capacity, and solving the technical bottleneck problem of heat pumps' inapplicability in extremely low temperature environments. Details are as follows:

[0022] In summer, when cooling load is not required, the solar photovoltaic power generation drives the compressor to perform cooling work, producing chilled water, which is then pumped to the energy storage device. When cooling load is required, the heat pump operates in cooling mode, producing chilled water, which is delivered to the room terminals to absorb heat from the air, lowering the air temperature and achieving a cooling effect. At the same time, the water pump delivers chilled water from the energy storage device to the condenser, lowering the condensing temperature, increasing the energy efficiency (EER), and improving the unit's cooling performance in high-temperature environments.

[0023] In winter, when the heat load is low or there is no heat load, the solar photovoltaic power generation drives the compressor to do work to generate heat. The hot water is stored in the energy storage device. When heating at night, the water pump delivers the stored hot water to the second economizer, which converts the low-grade heat source heat into heat generation through jet enthalpy increase. This can greatly improve the heat generation and heating performance coefficient.

[0024] Furthermore, the cooling modes include conventional cooling mode, full cold storage mode, partial cold storage mode, and high-efficiency cooling mode.

[0025] In normal cooling mode: the main electronic expansion valve and the first electronic expansion valve are open and adjusted according to certain control targets; the first solenoid valve is open; the second electronic expansion valve, the first subcooling electronic expansion valve, and the second subcooling electronic expansion valve are closed; the second solenoid valve is closed; the first water pump is on; and the second and third water pumps are off. The high-temperature gaseous refrigerant discharged from the compressor passes through the oil separator and the four-way valve, enters the heat exchanger, and exchanges heat with the air. After releasing heat, the refrigerant passes through the electronic expansion valve, the liquid receiver, and the first economizer, and enters the electronic expansion valve for throttling. The throttled refrigerant enters the heat exchanger, where it exchanges heat with water, absorbing heat from the water to produce chilled water. After absorbing heat, the refrigerant passes through the first solenoid valve, the second branch pipe, and the gas pipe shut-off valve back to the four-way valve, then enters the gas-liquid separator, and finally returns to the compressor, completing the refrigeration cycle. The chilled water produced in the process is pumped by the first water pump to the room terminal to exchange heat with the air, absorbing heat from the air and lowering the air temperature. The water after exchanging heat returns to the heat exchanger, continuously circulating.

[0026] In full cold storage mode: the main electronic expansion valve and the second electronic expansion valve are open and adjusted according to certain control targets; the second solenoid valve is open; the first electronic expansion valve, the first subcooled electronic expansion valve, and the second subcooled electronic expansion valve are closed; the first solenoid valve is closed; the second water pump is on; and the first and third water pumps are off. The high-temperature gaseous refrigerant discharged from compressor 1 passes through the oil separator and the four-way valve, enters the heat exchanger, and exchanges heat with the air. The refrigerant that has released heat passes through the electronic expansion valve, the liquid receiver, the first economizer, the liquid pipe shut-off valve, and the manifold, and enters the electronic expansion valve for throttling. The throttled refrigerant enters the energy storage tank, where it exchanges heat with the water, absorbing the heat from the water to produce cold water. The refrigerant that has absorbed heat passes through the solenoid valve, the second manifold, and the gas pipe shut-off valve, returns to the four-way valve, then enters the gas-liquid separator, and finally returns to the compressor, completing the cold storage cycle. The cold water produced in the energy storage tank is pumped by the third water pump and circulates in the heat exchanger, water pipes, and energy storage tank to lower the water temperature and achieve cold storage.

[0027] In partial cold storage mode: when cooling produces cold water, the process is the same as conventional heat pump cooling; when partial cold storage is used, the process is the same as full cold storage operation.

[0028] In high-efficiency cooling mode: the compressor starts, the fan on the heat exchanger starts, the four-way valve is de-energized, the electronic expansion valve opens (350-450 steps), the main electronic expansion valve opens and adjusts according to a certain control target, the first solenoid valve opens, the first electronic expansion valve, the first subcooling electronic expansion valve, and the second subcooling electronic expansion valve close, the second solenoid valve closes, the first and second water pumps start, and the third water pump closes. In this operating mode, the heat pump produces chilled water in the same way as in conventional cooling. At the same time, the second water pump pumps chilled water from the energy storage tank to the outdoor heat exchanger to exchange heat with the refrigerant in the outdoor heat exchanger.

[0029] As an improvement, after startup, under the refrigeration mode, the unit determines the operating mode according to the set conditions.

[0030] When there is no cooling load demand, the heat pump is in the standby state, and the photovoltaic power generation subsystem is used to drive the full cold storage mode operation. In this operating mode, the mains power is cut off, and the compressor is driven by solar power generation to do work for cold storage.

[0031] When the unit receives the refrigeration operation instruction, it conducts refrigeration operation according to the principle of preferring refrigeration operation. After the set refrigeration operation time, it makes a judgment. If the following conditions are met simultaneously, it conducts partial cold storage mode operation, that is, while producing chilled water by refrigeration, it conducts cold storage operation.

[0032] 1) The outdoor ambient temperature Tao < Tao,s1, where Tao,s1 is the temperature set by the user.

[0033] 2) The current water temperature T in the energy storage water tank tank,cur and the set water temperature T of the water tank tank,set1 satisfy: T tank,cur > T tank,set1 + set value 1;

[0034] 3) The heat pump return water temperature T w,in and the user-set outlet water temperature T set,c satisfy: T w,in > T set,c + set value 2;

[0035] 4) The power of the photovoltaic power generation subsystem is higher than X1% of the actual operating power of the unit.

[0036] 5) The current operating frequency INV_F of the compressor cur < (1 - ζ c ) × INV_F max , INV_F max is the maximum operating frequency set in the controller, ζ c is the cold storage ratio, ζ c = Q c,s / Q c , where Q c is the rated cooling capacity of the unit, Q C,s = ρ × V × C p × (T c,o - T c,tar )

[0037] In the formula: ρ and C p are the density of water 1000 kg / m 3 and the specific heat 4180 J / kg.℃ respectively; T c,0T represents the water temperature in the energy storage device before the machine starts cooling in summer. c,tar The target temperature for cold storage can be set customizable in the unit control program.

[0038] In a further improved version, partial cold storage will stop and switch to conventional or high-efficiency cooling operation mode when one of the following conditions is met during partial cold storage mode operation.

[0039] 1) Outdoor ambient temperature Tao > Tao,s2,T ao,s2 Set the temperature for the user.

[0040] 2) The current water temperature in the energy storage tank is lower than the set cold storage water temperature, i.e., T tank,cur <T tank,set1 -Set value 1,

[0041] 3) The power generated by solar photovoltaic power generation is less than 2% of the actual operating power.

[0042] Further improvements include the unit detecting the outdoor ambient temperature T. ao >T ao,s2 ,T ao,s2 Set the temperature for the user, and the current water temperature T in the energy storage tank. tan,cur <T ao -T ao,comp1 At ℃, T ao,comp1 When the compensation temperature is set to 1, the third water pump runs, pumping the cold water in the energy storage tank to the outdoor heat exchanger to exchange heat with the refrigerant in the outdoor heat exchanger, thus achieving a high-efficiency cooling operation mode.

[0043] When T tan,cur Tao-T ao,comp2 At ℃, T ao,comp2 When the compensation temperature is set to 2 (customizable), the third water pump stops running, enabling normal cooling mode operation.

[0044] On the other hand, the heating modes include conventional heating mode, full heat storage mode, partial heat storage mode and high-efficiency heating mode;

[0045] In normal heating mode: the main electronic expansion valve and the first electronic expansion valve open according to the set opening degree, the second solenoid valve opens, the second electronic expansion valve and the second subcooling electronic expansion valve close, the first solenoid valve closes, and the first water pump, the second water pump, and the third water pump are all closed; the first subcooling electronic expansion valve opens and is adjusted according to a certain control target; the high-temperature gaseous refrigerant discharged from the compressor passes through the oil separator, the four-way valve, the gas pipe shut-off valve, the second branch pipe, and the second solenoid valve, and enters the energy storage tank to exchange heat with the water. The refrigerant that releases heat passes through the second electronic expansion valve, the first branch pipe, and the liquid pipe shut-off valve, and enters the first economizer and the liquid tank, and then enters the main electronic expansion valve for throttling. The throttled refrigerant enters the outdoor heat exchanger, where it exchanges heat with the air. After absorbing heat, the refrigerant passes through the four-way valve, then enters the gas-liquid separator, and finally returns to the compressor to complete the heating cycle.

[0046] During this process, a portion of the refrigerant passing through the liquid line shut-off valve is throttled by the first subcooled electronic expansion valve and enters the first economizer. It exchanges heat with the refrigerant in the main circulation loop in the first economizer, and then, under the action of pressure difference, it is injected into the intermediate pressure chamber of the compressor through the first injection pipe.

[0047] In full heat storage mode: the main electronic expansion valve and the second electronic expansion valve are opened at their set openings, the second solenoid valve is open, the first electronic expansion valve and the second subcooled electronic expansion valve are closed, the first solenoid valve is closed, and the first water pump, the second water pump, and the third water pump are all closed; the first subcooled electronic expansion valve is open and adjusted according to a certain control target; the high-temperature gaseous refrigerant discharged from the compressor passes through the oil separator, the four-way valve, the gas pipe shut-off valve, the second branch pipe, and the second solenoid valve, and enters the energy storage water tank to exchange heat with the water; the refrigerant that has released heat passes through the second electronic expansion valve, the first branch pipe, and the liquid pipe shut-off valve, and enters the first economizer and the liquid tank, and then enters the main electronic expansion valve for throttling; the throttled refrigerant enters the outdoor heat exchanger, where it exchanges heat with the air; the refrigerant that has absorbed heat passes through the four-way valve, and then enters the gas-liquid separator, and finally returns to the compressor to complete the heating cycle;

[0048] During this process, a portion of the refrigerant passing through the liquid pipe shut-off valve is throttled by the first subcooled electronic expansion valve and enters the first economizer. It exchanges heat with the refrigerant in the main circulation loop in the first economizer, and then, under the action of pressure difference, it is injected into the intermediate pressure chamber of compressor 1 through the first injection pipe.

[0049] In partial heat storage mode: the main electronic expansion valve, the first electronic expansion valve, and the second electronic expansion valve are all open according to the set opening degree; the first solenoid valve and the second solenoid valve are both open; the second subcooled electronic expansion valve is closed; the first electric water pump is started; and the third and second water pumps are closed. When heating to produce hot water, the process is the same as the conventional heating of a heat pump. In partial heat storage mode, the process is the same as the full heat storage operation. In this process, a portion of the refrigerant passing through the liquid pipe shut-off valve is throttled by the first subcooled electronic expansion valve and enters the first economizer. It exchanges heat with the refrigerant in the main circulation loop in the first economizer and then, under the action of pressure difference, is injected into the intermediate pressure chamber of the compressor through the first injection pipe.

[0050] In high-efficiency heating mode: the main electronic expansion valve and the first electronic expansion valve open according to the set opening degree, the first solenoid valve opens, the second electronic expansion valve and the first subcooling electronic expansion valve close, the second solenoid valve closes, the first water pump and the second water pump open, and the third water pump closes; the high-temperature gaseous refrigerant discharged from the compressor passes through the oil separator, the four-way valve, the gas pipe shut-off valve, the second branch pipe and the first solenoid valve and then enters the heat exchanger to exchange heat with water. The refrigerant that releases heat passes through the first electronic expansion valve, the first branch pipe and the liquid pipe shut-off valve, enters the first economizer and the liquid tank, and then enters the main electronic expansion valve for throttling. The throttled refrigerant enters the outdoor heat exchanger, where it exchanges heat with the air. After absorbing heat, the refrigerant passes through the four-way valve and then enters the gas-liquid separator, and finally returns to the compressor to complete the heating cycle.

[0051] During this process, the second subcooled electronic expansion valve opens and is adjusted according to a certain control target. The hot water in the energy storage tank is pumped to the second economizer by the second water pump. The refrigerant and hot water in the second economizer exchange heat through the second subcooled electronic expansion valve and the second economizer. The refrigerant that absorbs heat is injected into the intermediate pressure chamber of the compressor through the second injection pipe.

[0052] As an improvement, after startup, in heating mode, the unit determines the operating mode based on set conditions. When there is no heat load demand, the heat pump is in standby mode and uses the photovoltaic power generation system to drive the full heat storage mode. In this mode, the mains power is cut off, and the compressor is driven by solar power to perform work and store heat. When the unit receives a heating operation command, it performs heating operation according to the principle of preferred heating operation. After the set operation time, a judgment is made. If the following conditions are met at the same time, the unit will operate in partial heat storage mode, that is, while producing cold water for heating, it will also perform partial heat storage operation.

[0053] 1) Outdoor ambient temperature Tao > T ao,s3 ,T ao,s3 Set the temperature for the user;

[0054] 2) The current water temperature in the energy storage tank is higher than the set water temperature T for thermal storage.tank,set2 Low setting value 1, T tank,cur <T tank,set2 -Set value 1;

[0055] 3) Temperature T of the hot water generated by the heat pump w,out <T set,h +Set value 2;

[0056] 4) The power output of solar photovoltaic power generation is more than 1% higher than the actual operating power of the unit;

[0057] 5) Compressor current operating frequency INV_F cur <(1-ζ h )×INV_F max INV_F max The maximum operating frequency set in the controller; ζ h For the heat storage ratio, ζ h =Q h,s / Q h Q h The rated cooling capacity of the unit.

[0058] Q h,s =ρ×V×C p ×(T h,tar -T h,o )

[0059] In the formula: ρ and C p The density of water is 1000 kg / m³. 3 Specific heat 4180 J / kg·℃; T h,0 T represents the water temperature in the energy storage device before the machine starts heating in winter. h,ta The target temperature for heat storage can be set customizable in the unit control program.

[0060] In a further improved version, partial heat storage will stop and switch to conventional heating mode when one of the following conditions is met during operation.

[0061] 1) Outdoor ambient temperature Tao <Tao,s4,T ao,s4 Set the temperature for the user;

[0062] 2) The current water temperature in the energy storage tank is higher than the set water temperature for cold storage, i.e., T tank,cur >T tank,set2 +Set value 2;

[0063] 3) The power generated by solar photovoltaic power generation is less than 2% of the actual operating power.

[0064] Further improvements include enabling the generator to detect the current water temperature T in the energy storage tank. tan,cur >T inj,outWhen the set value is 1, the second water pump runs and the second subcooled electronic expansion valve opens to a certain degree to perform active jet enthalpy enhancement.

[0065] When T tan,cur <T inj,out At that time, the second water pump stopped running, and the subcooled electronic expansion valve closed;

[0066] If the current water temperature T in the energy storage tank inj,out ≤T tan,cur ≤T inj,out +Set value 1, the unit maintains the current operating mode. Attached Figure Description

[0067] Figure 1 This is a system schematic diagram of the multi-energy complementary heat pump based on "photovoltaic storage direct current and flexible energy" according to the present invention;

[0068] Figure 2 This is a refrigerant flow diagram of the multi-energy complementary heat pump based on "photovoltaic storage direct-flexible" in the conventional refrigeration mode of the present invention.

[0069] Figure 3 This is a refrigerant flow diagram of the multi-energy complementary heat pump based on "photovoltaic storage direct-flexible" in the full cold storage mode of the present invention.

[0070] Figure 4 This is a refrigerant flow diagram of the multi-energy complementary heat pump based on "photovoltaic storage direct-flexible" in the partial cold storage mode of the present invention.

[0071] Figure 5 This is a refrigerant flow diagram of the multi-energy complementary heat pump based on "photovoltaic storage direct-flexible" in the high-efficiency cooling mode of the present invention.

[0072] Figure 6 This is a refrigerant flow diagram of the multi-energy complementary heat pump based on "photovoltaic storage direct-flexible" in the conventional heating mode of the present invention.

[0073] Figure 7 This is a refrigerant flow diagram of the multi-energy complementary heat pump based on "photovoltaic storage direct-flexible" in the full thermal storage mode of the present invention.

[0074] Figure 8 This is a refrigerant flow diagram of the multi-energy complementary heat pump based on "photovoltaic storage direct-flexible" in the partial heat storage mode of the present invention.

[0075] Figure 9 This is a refrigerant flow diagram of the multi-energy complementary heat pump based on "photovoltaic storage direct-flexible" in the high-efficiency heating mode of the present invention.

[0076] Explanation of reference numerals in the attached figures:

[0077] 1. Compressor; 2. Oil separator; 3. Four-way valve; 4. Outdoor heat exchanger; 5. Main electronic expansion valve; 6. Liquid storage tank; 7. Liquid pipe shut-off valve; 8. First branch pipe; 9. Second branch pipe; 10. Gas pipe shut-off valve; 11. Gas-liquid separator; 12. Oil return capillary tube; 13. First electronic expansion valve; 14. First solenoid valve; 15. Heat exchanger; 16. First water pump; 21. Energy storage tank; 22. Second electronic expansion valve; 23. Second solenoid valve; 24. Third water pump; 31. First subcooled electronic expansion valve; 32. First economizer; 33. First injection pipe; 41. Second subcooled electronic expansion valve; 42. Second economizer; 43. Second water pump; 44. Second injection pipe; 45. Injection main pipe; 51. Solar photovoltaic panel; 52. Inverter; 53. Filter. Detailed Implementation

[0078] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0079] 1. System Composition

[0080] This invention provides a method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" energy storage. The heat pump includes a heat pump subsystem, a first-stage vapor injection enthalpy enhancement subsystem, a second-stage vapor injection enthalpy enhancement subsystem, an energy storage subsystem, and a power supply system.

[0081] 1.1 Heat Pump Subsystem

[0082] The system includes a compressor 1, an oil separator 2, a four-way valve 3, an outdoor heat exchanger 4, a main electronic expansion valve 5, a liquid storage tank 6, a liquid line shut-off valve 7, a first branch pipe 8, a second branch pipe 9, a gas line shut-off valve 10, a gas-liquid separator 11, a first electronic expansion valve 13, a first solenoid valve 14, a heat exchanger 15, and a first water pump 16. Specifically, the outlet of compressor 1 connects to the first inlet of four-way valve 3 via oil separator 2. The first outlet of four-way valve 3 connects to one end of outdoor heat exchanger 4. The other end of outdoor heat exchanger 4 connects to one end of liquid storage tank 6 via main electronic expansion valve 5. The other end of liquid storage tank 6 connects to the first inlet of heat exchanger 15 via liquid line shut-off valve 7, first branch pipe 8, and first electronic expansion valve 13. The first outlet of heat exchanger 15 connects to the second inlet of four-way valve 3 via solenoid valve, second branch pipe 9, and gas-liquid shut-off valve. The second outlet of four-way valve 3 connects to the oil return port of compressor 1 via gas-liquid separator 11. (See [reference]). Figure 1 In this embodiment, an oil return capillary tube 12 is provided between the oil separator 2 and the return port of the compressor 1, and filters 53 are provided on the inlet and outlet pipes of the main electronic expansion valve 5, the first electronic expansion valve 13, and the second electronic expansion valve 22.

[0083] 1.2 Energy Storage Subsystem

[0084] It includes an energy storage tank 21, a second electronic expansion valve 22, a second solenoid valve 23, and a third water pump 24. One end of the second electronic expansion valve 22 is connected to the first branch pipe 8, and the other end is connected to the energy storage tank 21. One end of the second solenoid valve 23 is connected to the energy storage tank 21, and the other end is connected to the second branch pipe 9. The third water pump 24 is connected between the outdoor heat exchanger 4 and the energy storage tank 21.

[0085] 1.3 First-stage jet enthalpy enhancement subsystem

[0086] It includes a first subcooled electronic expansion valve 31, a first economizer 32, and a first injection pipe 33. The first inlet of the first economizer 32 is connected to the outlet of the liquid storage tank 6, the first outlet of the first economizer 32 is connected to the liquid pipe shut-off valve 7, and the first outlet of the first economizer 32 is connected to the compressor 1 via the first injection pipe 33. One end of the first subcooled electronic expansion valve 31 is connected to the second outlet of the first economizer 32, and the other end is connected to the second inlet of the first economizer 32.

[0087] 1.4 Second-stage jet enthalpy enhancement subsystem

[0088] It includes a second subcooled electronic expansion valve 41, a second economizer 42, a second water pump 43, and a second injection pipe 44. One end of the second subcooled electronic expansion valve 41 is connected to one end of the liquid storage tank 6, and the other end is connected to the first inlet of the second economizer 42. The first outlet of the second economizer 42 is connected to the compressor 1 via the second injection pipe 44. The second outlet and the second outlet of the second economizer 42 are both connected to the energy storage water tank 21.

[0089] 1.5 Power Supply System

[0090] It includes a photovoltaic power generation system and a mains power system; the photovoltaic power generation system includes a solar photovoltaic panel 51 and an inverter 52. The solar photovoltaic panel is connected to the compressor 1 through the inverter 52, and the mains power system directly supplies power to the compressor 1.

[0091] 2. Implementation Method

[0092] The cooling modes include conventional cooling mode, full cold storage mode, partial cold storage mode, and high-efficiency cooling mode.

[0093] 2.1 Conventional Cooling Mode

[0094] like Figure 2As shown, compressor 1 is turned on, the fan on heat exchanger 15 is turned on, four-way valve 3 is de-energized, main electronic expansion valve 5 and first electronic expansion valve 13 are turned on and adjusted according to a certain control target, first solenoid valve 14 is turned on, second electronic expansion valve 22, first subcooled electronic expansion valve 31 and second subcooled electronic expansion valve 41 are turned off, second solenoid valve 23 is turned off, first water pump 16 is turned on, second water pump 43 and third water pump 24 are turned off; the high-temperature gaseous refrigerant discharged from compressor 1 passes through oil separator 2 and four-way valve 3 and enters heat exchanger 15 to exchange heat with air. After releasing heat, the refrigerant passes through electronic expansion valve, After passing through the liquid storage tank 6, the first economizer 32, the liquid pipe shut-off valve 7, and the first branch pipe 8, the refrigerant enters the electronic expansion valve for throttling. The throttled refrigerant then enters the heat exchanger 15, where it exchanges heat with water, absorbing heat from the water to produce chilled water. After absorbing heat, the refrigerant passes through the first solenoid valve 14, the second branch pipe 9, and the gas pipe shut-off valve 10 back to the four-way valve 3, then enters the gas-liquid separator 11, and finally returns to the compressor 1, completing the refrigeration cycle. The chilled water produced during the process is pumped by the first water pump 16 to the room terminal to exchange heat with the air, absorbing heat from the air and lowering the air temperature. The water after exchanging heat returns to the heat exchanger 15, continuously circulating.

[0095] 2.2 Full Cold Storage Mode

[0096] The unit is equipped with a wired controller, which communicates with the controller of the heat pump main unit via a communication cable. When the unit controller determines that the unit is in "full cold storage" operation, the unit will operate in full cold storage mode, and the refrigerant flow direction is shown by the arrow.

[0097] like Figure 3As shown, compressor 1 is turned on, the fan on heat exchanger 15 is turned on, four-way valve 3 is de-energized, main electronic expansion valve 5 is opened with an opening degree of 350-450 steps, second electronic expansion valve 22 is opened and adjusted according to a certain control target, second solenoid valve 23 is opened, first electronic expansion valve 13, first subcooling electronic expansion valve 31, and second subcooling electronic expansion valve 41 are closed, first solenoid valve 14 is closed, second water pump 43 is turned on, first water pump 16 and third water pump 24 are closed; the high-temperature gaseous refrigerant discharged from compressor 1 passes through oil separator 2 and four-way valve 3, enters heat exchanger 15 to exchange heat with air, and releases heat. A certain amount of refrigerant passes through the electronic expansion valve, liquid storage tank 6, first economizer 32, liquid pipe shut-off valve 7, and manifold, then enters the second electronic expansion valve 22 for throttling. The throttled refrigerant then enters the energy storage tank, where it exchanges heat with water, absorbing heat to produce chilled water. After absorbing heat, the refrigerant passes through the solenoid valve, second manifold 9, and gas pipe shut-off valve 10, returning to the four-way valve 3, then entering the gas-liquid separator 11, and finally returning to the compressor 1, completing the cold storage cycle. The chilled water produced in the energy storage tank 21 is pumped by the third water pump 24, circulating through the heat exchanger 15, water pipes, and energy storage tank 21 to lower the water temperature and achieve cold storage. In this mode, solar energy is converted into chilled water for storage. When the cooling load is high, the stored chilled water is used for heat exchange and cooling, saving energy and improving efficiency.

[0098] 2.3 Partial Cold Storage Mode

[0099] like Figure 4 As shown, compressor 1 is turned on, the fan on heat exchanger 15 is turned on, four-way valve 3 is de-energized, main electronic expansion valve 5, first electronic expansion valve 13, and second electronic expansion valve 22 are turned on and adjusted according to a certain control target, first solenoid valve 14 and second solenoid valve 23 are turned on, first subcooling electronic expansion valve 31 and second subcooling electronic expansion valve 41 are turned off, first water pump 16 is turned on, and second water pump 43 and third water pump 24 are turned off.

[0100] The high-temperature gaseous refrigerant discharged from compressor 1 passes through oil separator 2 and four-way valve 3, and enters heat exchanger 15 to exchange heat with air. After releasing heat, the refrigerant passes through electronic expansion valve, liquid receiver 6, first economizer 32, liquid pipe shut-off valve 7, and first branch pipe 8, and then enters electronic expansion valve for throttling. Part of the throttled refrigerant enters heat exchanger 15, where it exchanges heat with water, absorbing heat from the water to produce chilled water. The other part of the throttled refrigerant enters energy storage tank, where it exchanges heat with water, absorbing heat from the water to produce chilled water, achieving partial cold storage. After absorbing heat, the refrigerant passes through second branch pipe 9, gas pipe shut-off valve 10, and solenoid valve, returning to four-way valve 3, then entering gas-liquid separator 11, and finally returning to compressor 1, completing the refrigeration cycle. The chilled water produced during the process is pumped by first water pump 16 to the room terminal to exchange heat with the air, absorbing heat from the air and lowering the air temperature. The water after exchanging heat returns to heat exchanger 15, continuously circulating.

[0101] 2.4 High-efficiency cooling mode

[0102] Based on the principles of air conditioning refrigeration, lowering the condensing temperature can improve energy efficiency and enhance cooling performance in high-temperature environments. This discovery utilizes chilled water to cool the condenser, thereby lowering the condensing temperature. The implementation process is as follows: Figure 5 As shown in the diagram, the unit is equipped with a wired controller and the heat pump main unit controller, which are connected via a communication cable for communication. When the unit controller determines that the operating status is "cooling" and detects that the conditions for high-efficiency operation are met, the unit will operate in high-efficiency mode, and the refrigerant flow direction is shown by the arrow.

[0103] like Figure 5 As shown, compressor 1 is turned on, the fan on heat exchanger 15 is turned on, four-way valve 3 is de-energized, main electronic expansion valve 5 is opened (350-450 steps), first electronic expansion valve 13 is opened and adjusted according to a certain control target, first solenoid valve 14 is opened, second electronic expansion valve 22, first subcooling electronic expansion valve 31, and second subcooling electronic expansion valve 41 are closed, second solenoid valve 23 is closed, first water pump 16 and second water pump 43 are turned on, and third water pump 24 is turned off. In this operating mode, the heat pump produces chilled water in the same way as conventional refrigeration. At the same time, second water pump 43 pumps chilled water from energy storage tank 21 to outdoor heat exchanger 4 to exchange heat with the refrigerant in outdoor heat exchanger 4, reducing the condensing temperature, improving the heat pump's cooling energy efficiency ratio, and improving the unit's cooling effect in high-temperature environments.

[0104] 3. Specific control methods for refrigeration operation mode

[0105] In order to better achieve energy conservation and ensure the efficient operation of the unit, in this embodiment, the controller in the unit automatically converts several specific operating modes in the refrigeration mode according to corresponding set conditions, that is, to avoid high-efficiency refrigeration when the cooling load is low or non-existent, resulting in energy waste.

[0106] 3.1 Refrigeration + Cold Energy Storage Mode

[0107] After starting up, the unit in the refrigeration mode determines the operating mode according to the set conditions.

[0108] After receiving the "refrigeration" startup instruction and starting up by the line controller, and when the return water temperature T w,in is higher than the user-set temperature T set,c by more than the set value 1, refrigeration operation is carried out. The set value 1 here is 2°C; following the principle of preferred refrigeration operation, refrigeration operation is carried out. After the set refrigeration operation time (which can be set to 30 - 45 minutes), a determination is made. If the following conditions are simultaneously met, partial cold energy storage mode operation is carried out, that is, while producing chilled water by refrigeration, cold energy storage operation is carried out.

[0109] 1) The outdoor ambient temperature Tao < Tao,s1, where Tao,s1 is the user-set temperature, and T ao,s1 can be set to 30 - 32°C;

[0110] 2) The current water temperature T tank,cur in the energy storage water tank 21 and the water tank set temperature T tank,set1 meet: T tank,cur > T tank,set1 + the set value 1; in this embodiment, it is: T tank,cur > T tank,set1 + 2°C

[0111] 3) The heat pump return water temperature T w,in and the user-set outlet water temperature T set,c meet: T w,in > T set,c + the set value 1; in this embodiment, it is: T w,in > T set,c + 2°C, that is, the heat pump refrigeration operation condition is met;

[0112] If during the operation process, T w,in < T set,c - 2°C, the heat pump refrigeration stops, and a determination is made whether the full cold energy storage condition is met. If it is met, the heat pump conducts full cold energy storage operation; when T set,c - 2 ≤ T w,in ≤ T set,c + 2°C, the heat pump maintains the current operating state;

[0113] 4) The power of the photovoltaic power generation system is higher than X1% (X1 can be set to 70-100) of the actual operating power of the unit;

[0114] 5) Current operating frequency of compressor 1, INV_F cur <(1-ζ c )×INV_F max INV_F max ζ is the maximum operating frequency set in the controller. c This refers to the cold storage ratio.

[0115] 3.2 Full Cold Storage Mode

[0116] When the wired controller receives the "cooling" start command and starts the machine, the controller makes a judgment. When there is no cooling load demand, the heat pump is in standby mode and then the photovoltaic power generation system is used to drive the full cold storage mode. In this mode, the mains power is cut off and the compressor 1 is driven by solar power generation to do work and store cold. The operating frequency of the compressor 1 is adjusted in real time according to the amount of power generation.

[0117] During the full cold storage process, when the wired controller receives a "cooling" operation command, it will initiate cooling operation based on the principle of prioritizing cooling operation. After half an hour of cooling operation, a judgment will be made. If the conditions for partial cold storage are met, partial cold storage operation will be initiated.

[0118] 3.3 High-efficiency cooling mode

[0119] When the wired controller receives the "cooling" start command, the unit starts cooling and determines whether the energy storage device should release cold water. When the following conditions are met simultaneously, the stored cold water is released.

[0120] If any of the following conditions are met during the operation of the aforementioned partial cold storage mode, partial cold storage will stop and the system will switch to conventional cooling or high-efficiency cooling operation mode.

[0121] 1) Outdoor ambient temperature Tao > Tao,s2,T ao,s2 Set the temperature for the user; here it is 34-36℃.

[0122] 2) The current water temperature in the energy storage tank 21 is lower than the set cold storage water temperature, i.e., T tank,cur <T tank,set1 -Set value 1, here is T tank,cur <T tank,set1 -2℃

[0123] 3) The power generated by solar photovoltaic power generation is less than 2% of the actual operating power (X2 can be set to 60-65).

[0124] Furthermore, in this mode, the outdoor ambient temperature Tao,s1≤Tao≤Tao,s2 serves as the criterion for maintaining the current cold storage operation state. tank,set1 -2≤T tank,cur ≤T tank,set1 At +2℃, as a criterion for maintaining the current cold storage operation state, the power of solar photovoltaic power generation is between X1% and X2% of the actual operating power.

[0125] More specifically, in the above mode, when the unit detects the outdoor ambient temperature T ao >T ao,s2 ,T ao,s2 Set the temperature for the user, here it is 33-36℃, and the current water temperature T in the energy storage tank 21 is... tan,cur <T ao -T ao,comp1 At ℃, T ao,comp1 The compensation temperature 1 is customizable and can be set in the control program. Here, the compensation temperature 1 is 5-8℃. The third water pump 24 runs and pumps the cold water in the energy storage tank 21 to the outdoor heat exchanger to exchange heat with the refrigerant in the outdoor heat exchanger, thus achieving a high-efficiency cooling operation mode.

[0126] When T tan,cur Tao-T ao,comp2 At ℃, T ao,comp2 The compensation temperature 2 is customizable; specific parameters can be set in the control program. Here, compensation temperature 2 is set to 3-4℃. The third water pump 24 stops operating, achieving normal cooling mode operation. Furthermore, in this mode, Tao-T... ao,comp1 ≤T tan,cur ≤Tao-T ao,comp2 This serves as a criterion for determining whether the third water pump 24 maintains its current operating state.

[0127] 4. Heating modes include conventional heating mode, full heat storage mode, partial heat storage mode, and high-efficiency heating mode;

[0128] 4.1 Conventional Heating Mode

[0129] To improve energy efficiency, vapor injection enthalpy enhancement is employed. A wired controller is designed on the unit, connected to the heat pump main unit's controller via a communication line. When the wired controller receives a "heating" command, the unit initiates heating operation, with the refrigerant flow direction as follows: Figure 6 As shown by the arrow in the image.

[0130] When the unit starts up, compressor 1 turns on, the fan on heat exchanger 15 turns on, four-way valve 3 is energized, main electronic expansion valve 5 opens and its opening degree is adjusted according to a certain control target, first electronic expansion valve 13 opens according to the set opening degree (350-450 steps), second solenoid valve 23 opens, second electronic expansion valve 22 and second subcooling electronic expansion valve 41 close, first solenoid valve 14 closes, and first water pump 16, second water pump 43, and third water pump 24 are all closed; first subcooling electronic expansion valve 31 opens and is adjusted according to a certain control target; high-temperature air discharged from compressor 1... The warm gaseous refrigerant passes through the oil separator 2, four-way valve 3, gas pipe shut-off valve 10, second branch pipe 9, and second solenoid valve 23, and enters the energy storage water tank 21 to exchange heat with water. The refrigerant that releases heat passes through the second electronic expansion valve 22, first branch pipe 8, and liquid pipe shut-off valve 7, and enters the first economizer 32 and liquid storage tank 6. It then enters the main electronic expansion valve 5 for throttling. The throttled refrigerant enters the outdoor heat exchanger 4, where it exchanges heat with the air. After absorbing heat, the refrigerant passes through the four-way valve 3 and then enters the gas-liquid separator 11, finally returning to the compressor 1 to complete the heating cycle.

[0131] During this process, a portion of the refrigerant passing through the liquid pipe shut-off valve 7 is throttled by the first subcooled electronic expansion valve 31 and enters the first economizer 32, where it exchanges heat with the refrigerant in the main circulation loop. Then, under the action of the pressure difference, it is injected into the intermediate pressure chamber of the compressor 1 through the first injection pipe 33 and the injection manifold 45.

[0132] 4.2 Full Heat Storage Mode

[0133] like Figure 7 As shown, compressor 1 is turned on, the fan on heat exchanger 15 is turned on, four-way valve 3 is energized, main electronic expansion valve 5 is opened and its opening degree is adjusted according to a certain control target, second electronic expansion valve 22 is opened according to the set opening degree, the opening degree is 350-450 steps, second solenoid valve 23 is opened, first electronic expansion valve 13, second subcooling electronic expansion valve 41 are closed, first solenoid valve 14 is closed, first water pump 16, second water pump 43, and third water pump 24 are all closed; first subcooling electronic expansion valve 31 is opened and adjusted according to a certain control target; high-temperature gaseous gas discharged from compressor 1 The refrigerant passes through the oil separator 2, four-way valve 3, gas pipe shut-off valve 10, second branch pipe 9, and second solenoid valve 23, and enters the energy storage water tank 21 to exchange heat with water. The refrigerant that releases heat passes through the second electronic expansion valve 22, first branch pipe 8, and liquid pipe shut-off valve 7, and enters the first economizer 32 and liquid storage tank 6, and then enters the main electronic expansion valve 5 for throttling. The throttled refrigerant enters the outdoor heat exchanger 4, where it exchanges heat with the air. After absorbing heat, the refrigerant passes through the four-way valve 3, then enters the gas-liquid separator 11, and finally returns to the compressor 1 to complete the heating cycle.

[0134] During this process, a portion of the refrigerant passing through the liquid pipe shut-off valve 7 is throttled by the first subcooled electronic expansion valve 31 and enters the first economizer 32, where it exchanges heat with the refrigerant in the main circulation loop. Then, under the action of the pressure difference, it is injected into the intermediate pressure chamber of the compressor 1 through the first injection pipe 33 and the injection manifold 45.

[0135] 4.3 Partial Heat Storage Mode

[0136] like Figure 8 As shown, the unit is designed with a wired controller and the heat pump main unit's controller connected via a communication line for communication. When the wired controller receives a "heating" command, and the controller detects that the conditions for "partial heat storage" operation are met, the unit performs partial heat storage operation. That is, the heat pump generates hot water while simultaneously storing heat, heating the water in the energy storage tank. The process is as follows: Figure 8 As shown, the refrigerant flow direction is indicated by the arrow.

[0137] When the unit starts up, the main electronic expansion valve 5, the first electronic expansion valve 13, and the second electronic expansion valve 22 are all opened according to the set opening degree. The first solenoid valve 14 and the second solenoid valve 23 are both open, the second subcooled electronic expansion valve 41 is closed, the first electric water pump starts up, and the third water pump 24 and the second water pump 43 are closed. When heating to produce hot water, the process is the same as conventional heating of a heat pump. When partially storing heat, the process is the same as full heat storage operation. In this process, the refrigerant passing through the liquid pipe shut-off valve 7, part of the refrigerant is throttled by the first subcooled electronic expansion valve 31 and enters the first economizer 32, where it exchanges heat with the refrigerant in the main circulation loop. Then, under the action of pressure difference, it is injected into the intermediate pressure chamber of the compressor 1 through the first injection pipe 33 and the injection main pipe 45.

[0138] 4.4 High-efficiency heating mode

[0139] like Figure 9 As shown, an active vapor injection enthalpy enhancement method is adopted to improve heating capacity and energy efficiency ratio. Hot water in the energy storage tank 21 is pumped to the first economizer 32 for heat exchange with the injected refrigerant. After absorbing heat, the refrigerant is injected into the intermediate pressure chamber of compressor 1 under pressure difference, converting the heat of the stored hot water into heating capacity in the form of injection enthalpy difference, significantly improving heat pump performance. A wired controller is designed on the unit and connects to the controller of the heat pump main unit via a communication line. When the wired controller receives a "heating" command and the secondary active vapor injection enthalpy enhancement conditions are met, high-efficiency heating operation is initiated, as shown in the diagram. Figure 9 As shown.

[0140] When the unit starts up, compressor 1 turns on, the fan on heat exchanger 15 turns on, and four-way valve 3 is energized; main electronic expansion valve 5 opens, and its opening degree is adjusted according to a certain control target; first electronic expansion valve 13 opens according to the set opening degree, which is 350-450 steps; first solenoid valve 14 opens; second electronic expansion valve 22 and first subcooling electronic expansion valve 31 close; second solenoid valve 23 closes; first water pump 16 and second water pump 43 turn on, and third water pump 24 closes; the high-temperature gaseous refrigerant discharged from compressor 1 passes through oil separator 2. After passing through the four-way valve 3, gas pipe shut-off valve 10, second branch pipe 9, and first solenoid valve 14, the refrigerant enters the heat exchanger 15 to exchange heat with water. The refrigerant that releases heat passes through the first electronic expansion valve 13, first branch pipe 8, and liquid pipe shut-off valve 7, enters the first economizer 32 and liquid storage tank 6, and then enters the main electronic expansion valve 5 for throttling. The throttled refrigerant enters the outdoor heat exchanger 4, where it exchanges heat with the air. After absorbing heat, the refrigerant passes through the four-way valve 3, then enters the gas-liquid separator 11, and finally returns to the compressor 1 to complete the heating cycle.

[0141] In this process, in order to improve heating capacity and energy efficiency, a two-stage jet enthalpy enhancement is performed, that is, the second subcooled electronic expansion valve 41 is opened and adjusted according to a certain control target. The hot water in the energy storage tank 21 is pumped to the second economizer 42 by the second water pump 43. The refrigerant and hot water in the second subcooled electronic expansion valve 41 and the second economizer 42 exchange heat. The refrigerant that absorbs heat is injected into the intermediate pressure chamber of the compressor 1 through the second injection pipe 44 and the injection main pipe 45.

[0142] 5. Specific control methods for heating operation mode

[0143] 5.1 Heating + Heat Storage Mode

[0144] When the unit receives a heating operation command, it will operate in heating mode according to the principle of preferred heating operation. After the set operation time, it will make a judgment. If the following conditions are met at the same time, it will operate in partial heat storage mode, that is, while producing cold water for heating, it will also operate in partial heat storage mode.

[0145] 1) Outdoor ambient temperature Tao > T ao,s3 ,T ao,s3 Set the temperature for the user; here it is 10-12℃.

[0146] 2) The current water temperature in the energy storage tank 21 is higher than the set water temperature T for heat storage. tank,set2 Low setting value 1, T tank,cur <T tank,set2 - Setting value 1, where setting value 1 is 2℃;

[0147] 3) Temperature T of the hot water generated by the heat pump w,out <T set,h+Setting value 2, where setting value 2 is 1℃; when T w,out <T set,h At -1℃, the heat pump stops heating to determine if the full heat storage conditions are met. If so, the heat pump operates in full heat storage mode; when T... set,h -1≤T w,out ≤T set,h +1℃, the heat pump remains in its current operating state.

[0148] 4) The power generated by solar photovoltaic power generation is more than Y1% (Y1 can be set to 70-100) higher than the actual operating power of the unit;

[0149] 5) Current operating frequency of compressor 1, INV_F cur <(1-ζ h )×INV_F max INV_F max The maximum operating frequency set in the controller; ζ h The heat storage ratio;

[0150] 5.2 Full Heat Storage Mode

[0151] After startup, in heating mode, the unit determines the operating mode based on the set conditions.

[0152] When there is no heat load demand, the heat pump is in standby mode and is driven by a photovoltaic power generation system to operate in full heat storage mode. In this operating mode, the mains power is cut off and the compressor 1 is driven by solar power generation to perform work and store heat.

[0153] During the full heat storage process, when the heat load demand increases, heating operation is prioritized based on the principle of optimal heating operation. After half an hour of heating operation, a judgment is made; if the conditions for partial heat storage are met, partial heat storage operation is then initiated.

[0154] 5.3 High-efficiency heating operation mode

[0155] When the wired controller receives a "heating" start command, the unit starts cooling and determines whether the energy storage device is releasing heat. More specifically, during the operation of the aforementioned partial heat storage mode, if one of the following conditions is met, partial heat storage will stop and switch to the regular heating mode.

[0156] 1) Outdoor ambient temperature Tao <Tao,s4,T ao,s4 Set the temperature for the user; here it is 6-8 degrees Celsius.

[0157] 2) The current water temperature in the energy storage tank 21 is higher than the set cold storage water temperature, i.e., T tank,cur >T tank,set2 +Setting value 2, where setting value 2 is 1℃;

[0158] 3) The power generated by solar photovoltaic power generation is less than Y2% of the actual operating power (Y2 can be set to 60-65).

[0159] On another note, in the aforementioned heating mode, when the unit detects the current water temperature T in the energy storage tank 21... tan,cur >T inj,out When the setting value is 1, which is 2°, the second water pump 43 runs and the second subcooled electronic expansion valve 41 opens to a certain degree, usually 300-450 steps, to perform active jet enthalpy enhancement. At this time, the heat source of the energy storage tank 21 can serve as the external heat source of the secondary jet enthalpy enhancement subsystem, thereby improving the heating effect and energy efficiency.

[0160] When T tan,cur <T inj,out At this time, the second water pump 43 stops operating, and the second subcooling electronic expansion valve 41 closes; if the current water temperature T in the energy storage tank 21 is... inj,out ≤T tan,cur ≤T inj,out +Setting value 1, here setting value 1 is 2℃, the unit maintains the current two-stage injection mode operation.

[0161] 6. Power supply switching method

[0162] This invention features a dual power input design: photovoltaic DC power and AC mains power. The heat pump controller includes a relay that controls an AC contactor. The external mains power is connected to the AC contactor, and the relay's output controls the contactor's on / off state, thereby controlling the external power supply. Different power supply methods are used for different operating modes of the heat pump.

[0163] 6.1 Full Cooling Mode

[0164] When the unit operates in full cooling mode, it employs a control method that combines solar photovoltaic power generation with grid power supplementation. When the photovoltaic power generation exceeds the machine's operating power, the electricity required for the heat pump's operation is supplied by the photovoltaic power generation, with any excess electricity transmitted to the grid. When the photovoltaic power generation is lower than the machine's operating power, the electricity required for the heat pump's operation is supplied by the photovoltaic power generation, supplemented by grid power.

[0165] 6.2 Cooling + Cold Storage Mode

[0166] When the unit meets the partial cooling storage mode (cooling + cooling storage), the unit activates cooling storage, and the power supply is provided by solar photovoltaic power generation supplemented by grid power. When the photovoltaic power generation is higher than the machine's operating power, the electricity required for the heat pump to operate is supplied by the photovoltaic power generation, and the excess electricity is transmitted to the grid through grid connection. When the photovoltaic power generation is lower than the power required for the machine to operate, the electricity required for the heat pump to operate is supplied by the photovoltaic power generation, while the grid power provides supplementation.

[0167] 6.3 Full Cold Storage Mode

[0168] When the heat pump operates in full cold storage mode, photovoltaic power generation drives the heat pump compressor 1 to perform work, and the mains power is cut off. The power supply switching method is as follows:

[0169] The heat pump control system includes a relay that controls the AC contactor. The external AC power supply is connected to the AC contactor, and the controller controls the relay to disconnect the AC contactor, thus stopping the AC power supply to the heat pump.

[0170] 6.4 Full heating

[0171] When the unit operates in full heating mode, it employs a control method that combines solar photovoltaic power generation with grid power supplementation. When the photovoltaic power generation capacity exceeds the machine's operating power, the electricity required for the heat pump's operation is supplied by the photovoltaic power generation, with any excess electricity transmitted to the grid. When the photovoltaic power generation capacity is lower than the machine's operating power, the electricity required for the heat pump's operation is supplied by the photovoltaic power generation, while grid power supplementation is provided.

[0172] 6.5 Heating + Partial Heat Storage Mode

[0173] When the unit meets the heating + partial heat storage mode, the solar power generation is judged. The judgment method is: if the power of solar photovoltaic power generation is higher than Y1% of the actual operating power of the unit (Y1 can be set to 70-100), the cold storage is activated, and the power supply is solar photovoltaic power generation and mains power supplement. The switching method is the same as the power switching method in the full heating mode.

[0174] 6.6 Full Heat Storage Mode

[0175] When the heat pump operates in full heat storage mode, photovoltaic power generation drives the heat pump compressor 1 to perform work, and the mains power is cut off. The power supply switching method is as follows:

[0176] The heat pump control system includes a relay that controls the AC contactor. The external AC power supply is connected to the AC contactor, and the controller controls the relay to disconnect the AC contactor, thus stopping the AC power supply to the heat pump.

[0177] 7. Calculation methods for cold storage capacity and heat storage capacity of energy storage devices

[0178] Assuming the energy storage tank 21 has a volume of V, an initial water temperature of T0, and target temperatures after cold and heat storage of T0 and T1 respectively, the energy storage tank 21 has a volume of V, an initial water temperature of T0, and target temperatures after cold and heat storage of T0 respectively. c,tar (This can be set in the unit control program, such as 18℃) and T h,tar (This can be set in the unit control program, such as to 50℃), and the corresponding cold storage capacity and heat storage capacity are Q, respectively. c,s and Q h,s The calculation formulas are as follows:

[0179] Q C,s =ρ×V×Cp ×(T c,o -T c,tar (1)

[0180] Q h,s =ρ×V×C p ×(T h,tar -T h,o (2)

[0181] In the formula: ρ and C p The density of water (1000 kg / m³) 3 ) and specific heat (4180 J / kg·℃). T c,0 ,T h,0 These are the water temperatures in the energy storage tank 21 before the machine starts cooling in summer and the water temperatures in the energy storage tank 21 before the machine starts heating in winter, respectively.

[0182] The rated cooling capacity and rated heating capacity of the unit are Q c Q h This is the value on the generator nameplate, which is input into the control program.

[0183] Cold storage ratio ζ c And heat storage ratio ζ h Defined respectively

[0184] ζ c =Q c,s / Q c (3)

[0185] ζ h =Q h,s / Q h (4)

[0186] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" technology, wherein the heat pump includes a heat pump subsystem, the heat pump subsystem including a compressor (1), an oil separator (2), a four-way valve (3), an outdoor heat exchanger (4), a main electronic expansion valve (5), a liquid storage tank (6), a liquid pipe shut-off valve (7), a first branch pipe (8), a second branch pipe (9), a gas pipe shut-off valve (10), a gas-liquid separator (11), a first electronic expansion valve (13), a first solenoid valve (14), a heat exchanger (15), and a first water pump (16), wherein the outlet of the compressor (1) is connected to the inlet of the four-way valve (3) after passing through the oil separator (2), the four-way valve ( 3) The first outlet is connected to one end of the outdoor heat exchanger (4), and the other end of the outdoor heat exchanger (4) is connected to one end of the liquid storage tank (6) after passing through the main electronic expansion valve (5). The other end of the liquid storage tank (6) is connected to the first inlet of the heat exchanger (15) after passing through the liquid pipe shut-off valve (7), the first branch pipe (8), and the first electronic expansion valve (13) in sequence. The first outlet of the heat exchanger (15) is connected to the second inlet of the four-way valve (3) after passing through the solenoid valve, the second branch pipe (9), and the gas-liquid shut-off valve in sequence. The second outlet of the four-way valve (3) is connected to the oil return port of the compressor (1) after passing through the gas-liquid separator (11). The characteristic is that: The heat pump also includes a primary vapor injection enthalpy enhancement subsystem, a secondary vapor injection enthalpy enhancement subsystem, an energy storage subsystem, and a power supply system; The energy storage subsystem includes an energy storage tank (21), a second electronic expansion valve (22), a second solenoid valve (23), and a third water pump (24). One end of the second electronic expansion valve (22) is connected to the first branch pipe (8), and the other end is connected to the energy storage tank (21). One end of the second solenoid valve (23) is connected to the energy storage tank (21), and the other end is connected to the second branch pipe (9). The third water pump (24) is connected between the outdoor heat exchanger (4) and the energy storage tank (21). The first-stage jet enthalpy enhancement subsystem includes a first subcooled electronic expansion valve (31), a first economizer (32), and a first injection pipe (33). The first inlet of the first economizer (32) is connected to the outlet of the liquid storage tank (6), and the first outlet of the first economizer (32) is connected to the liquid pipe shut-off valve (7). The first outlet of the first economizer (32) is connected to the compressor (1) via the first injection pipe (33). One end of the first subcooled electronic expansion valve (31) is connected to the second outlet of the first economizer (32), and the other end is connected to the second inlet of the first economizer (32). The secondary jet enthalpy enhancement subsystem includes a second subcooled electronic expansion valve (41), a second economizer (42), a second water pump (43), and a second injection pipe (44). One end of the second subcooled electronic expansion valve (41) is connected to one end of the liquid storage tank (6), and the other end is connected to the first inlet of the second economizer (42). The first outlet of the second economizer (42) is connected to the compressor (1) via the second injection pipe (44). The second outlet and the second outlet of the second economizer (42) are both connected to the energy storage tank (21). The power supply system includes a photovoltaic power generation system and a mains power system; The heat pump operates in two modes: cooling and heating. The specific implementation methods are as follows: a: When the unit is turned on, it operates according to the relevant instructions received by the wired controller. The wired controller is electrically connected to the heat pump controller. b: When the unit receives the cooling command and starts running, the controller determines the load source. When there is no cooling load, the heat pump subsystem runs cooling and the generated cold water can be stored in the energy storage tank (21). When there is a cooling load, the heat pump subsystem runs cooling and the cold water generated by the heat exchanger (15) is delivered to the end of the room. When the cooling load is high, while running cooling, the third water pump (24) is used to deliver the cold water in the energy storage tank (21) to the outdoor heat exchanger (4). When the unit receives a heating command and starts operating, the controller determines the load source. When there is no heat load or the heat load is low, the heat pump subsystem operates to heat, and the hot water can be stored in the energy storage tank (21). When heating, the first-stage jet enthalpy enhancement subsystem is operated. The refrigerant passing through the liquid pipe shut-off valve (7) is partially throttled by the subcooled electronic expansion valve and enters the first economizer (32) to exchange heat with the refrigerant in the main circulation loop in the first economizer (32). When the heat load is high, the heat pump subsystem operates to heat, and at the same time, the second-stage jet enthalpy enhancement subsystem is operated. The second water pump (43) can be used to transport the hot water in the energy storage tank (21) to the second economizer (42) to exchange heat with the jet refrigerant, and convert the low-grade heat source heat into heat generation by jet enthalpy enhancement. During operation in either cooling or heating mode, when the photovoltaic power generation is higher than the machine's operating power, the electrical energy required for the heat pump to operate is supplied by the photovoltaic power generation system; when the photovoltaic power generation is lower than the machine's operating power, the electrical energy required for the heat pump to operate is supplied by the photovoltaic power generation system, supplemented by the mains power system.

2. The method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" energy storage as described in claim 1, characterized in that: The cooling modes include conventional cooling mode, full cold storage mode, partial cold storage mode, and high-efficiency cooling mode. In normal cooling mode: the high-temperature gaseous refrigerant discharged by the compressor (1) passes through the oil separator (2) and the four-way valve (3) and enters the outdoor heat exchanger (4) to exchange heat with the air. After releasing heat, the refrigerant passes through the electronic expansion valve, the liquid tank (6), and the first economizer (32) and enters the electronic expansion valve for throttling. After throttling, the refrigerant enters the heat exchanger (15) to exchange heat with water and absorb the heat of the water to produce cold water. After absorbing heat, the refrigerant passes through the first solenoid valve (14), the second branch pipe (9), and the gas pipe shut-off valve (10) and returns to the four-way valve (3), then enters the gas-liquid separator (11) and finally returns to the compressor (1) to complete the cooling cycle. The cold water produced in the process is pumped to the room terminal by the first water pump (16) to exchange heat with the air, absorb the heat in the air, and reduce the air temperature. After exchanging heat, the water returns to the heat exchanger (15) and continues to circulate. In full cold storage mode: the high-temperature gaseous refrigerant discharged by the compressor (1) passes through the oil separator (2) and the four-way valve (3) and enters the outdoor heat exchanger (4) to exchange heat with the air. The refrigerant that releases heat passes through the electronic expansion valve, the liquid tank (6), the first economizer (32), the liquid pipe shut-off valve (7) and the manifold, and enters the second electronic expansion valve (22) for throttling. The throttled refrigerant enters the energy storage tank, where it exchanges heat with the water and absorbs the heat of the water to produce cold water. The refrigerant that has absorbed heat passes through the solenoid valve, the second manifold (9) and the gas pipe shut-off valve (10) and returns to the four-way valve (3), then enters the gas-liquid separator (11) and finally returns to the compressor (1) to complete the cold storage cycle. The cold water produced in the energy storage tank (21) is pumped by the third water pump (24) and circulates in the heat exchanger (15), water pipe and energy storage tank (21) to reduce the water temperature and achieve cold storage. In partial cold storage mode: when cooling produces cold water, the process is the same as conventional heat pump cooling; when partial cold storage is used, the process is the same as full cold storage operation. In high-efficiency cooling mode: In this operating mode, the heat pump generates cold water in the same way as in conventional cooling. At the same time, the second water pump (43) pumps the cold water in the energy storage tank (21) to the outdoor heat exchanger (4) to exchange heat with the refrigerant in the outdoor heat exchanger (4).

3. The method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" energy storage as described in claim 2, characterized in that: After powering on, in cooling mode, the unit determines the operating mode based on the set conditions. When there is no cooling load demand, the heat pump is in standby mode and is driven by a photovoltaic power generation system to operate in full cold storage mode. In this operating mode, the mains power is cut off and the compressor (1) is driven by solar power generation to do work and store cold. When the unit receives a cooling operation command, it will perform cooling operation according to the principle of cooling operation priority. After the cooling operation is set for a time, it will make a judgment. If the following conditions are met at the same time, it will operate in partial cold storage mode, that is, while producing cold water, it will perform cold storage operation. 1) Outdoor ambient temperature Tao < Tao,s1, where Tao,s1 is the user-set temperature; 2) The current water temperature T in the energy storage tank (21) tank,cur and the water tank set temperature T tank,set1 Satisfy: T tank,cur > T tank,set1 +Set value 1; 3) Heat pump return water temperature T w,in With the user-set outlet water temperature T set,c Satisfy: T w,in >T set,c +Set value 1; 4) The power output of the photovoltaic power generation system is more than 1% higher than the actual operating power of the unit; 5) Compressor (1) Current operating frequency INV_F cur < (1-ζ c )×INV_F max INV_F max ζ is the maximum operating frequency set in the controller. c For the cold storage ratio, ζ c =Q c,s / Q c Q c The rated cooling capacity of the unit. In the formula: ρ and C p The density of water is 1000 kg / m³. 3 Specific heat 4180 J / kg·℃; T c,0 T represents the water temperature in the energy storage tank (21) before the machine starts cooling in summer. c,tar The target temperature for cold storage can be set customizable in the unit control program.

4. The method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" as described in claim 3, characterized in that: During partial cold storage mode operation, partial cold storage will stop and switch to conventional cooling or high-efficiency cooling operation mode when one of the following conditions is met. 1) Outdoor ambient temperature Tao > Tao,s2, T ao,s2 Set the temperature for the user. 2) The current water temperature in the energy storage tank (21) is lower than the set cold storage water temperature, i.e., T tank,cur < T tank,set1 -Set value 1, 3) The power generated by solar photovoltaic power generation is less than 2% of the actual operating power.

5. The method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" as described in claim 4, characterized in that: When the unit detects the outdoor ambient temperature T ao > T ao,s2 , T ao,s2 Set the temperature for the user, and the current water temperature T in the energy storage tank (21) tan,cur <T ao -T ao,comp1 At ℃, T ao,comp1 For the customizable compensation temperature 1, the third water pump (24) operates, pumping the cold water in the energy storage tank (21) to the outdoor heat exchanger (4) to exchange heat with the refrigerant, thus achieving a high-efficiency cooling operation mode; When T tan,cur >Tao- T ao,comp2 At ℃, T ao,comp2 When the compensation temperature is set to 2, the third water pump (24) stops running, and the normal cooling mode is realized.

6. The method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" as described in claim 1, characterized in that: The heating modes include conventional heating mode, full heat storage mode, partial heat storage mode, and high-efficiency heating mode. In the normal heating mode: the high-temperature gaseous refrigerant discharged by the compressor (1) passes through the oil separator (2), four-way valve (3), gas pipe shut-off valve (10), second branch pipe (9) and second solenoid valve (23), and enters the energy storage tank (21) to exchange heat with water. The refrigerant that releases heat passes through the second electronic expansion valve (22), first branch pipe (8) and liquid pipe shut-off valve (7), enters the first economizer (32) and liquid storage tank (6), and enters the main electronic expansion valve (5) for throttling. The throttled refrigerant enters the outdoor heat exchanger (4), where the refrigerant exchanges heat with the air. After absorbing heat, the refrigerant passes through the four-way valve (3), then enters the gas-liquid separator (11), and finally returns to the compressor (1) to complete the heating cycle. During this process, the refrigerant passing through the liquid pipe shut-off valve (7) is partially throttled by the first subcooled electronic expansion valve (31) and enters the first economizer (32), where it exchanges heat with the refrigerant in the main circulation loop in the first economizer (32). Then, under the action of pressure difference, it is injected into the intermediate pressure chamber of the compressor (1) through the first injection pipe (33). In full heat storage mode: the high-temperature gaseous refrigerant discharged by the compressor (1) passes through the oil separator (2), four-way valve (3), gas pipe shut-off valve (10), second branch pipe (9) and second solenoid valve (23), and enters the energy storage water tank (21) to exchange heat with water. The refrigerant that releases heat passes through the second electronic expansion valve (22), first branch pipe (8) and liquid pipe shut-off valve (7), enters the first economizer (32), liquid storage tank (6) and then enters the main electronic expansion valve (5) for throttling. The throttled refrigerant enters the outdoor heat exchanger (4) to exchange heat with the refrigerant and air. The refrigerant that absorbs heat passes through the four-way valve (3) and then enters the gas-liquid separator (11), and finally returns to the compressor (1) to complete the heating cycle. During this process, the refrigerant passing through the liquid pipe shut-off valve (7) is partially throttled by the first subcooled electronic expansion valve (31) and enters the first economizer (32). The refrigerant in the main circulation loop exchanges heat in the first economizer (32), and then, under the action of pressure difference, it is injected into the intermediate pressure chamber of the compressor (1) through the first injection pipe (33). In partial heat storage mode: when heating to produce hot water, the process is the same as conventional heat pump heating. In partial heat storage mode, the process is the same as full heat storage operation. In this process, the refrigerant passing through the liquid pipe shut-off valve (7) is throttled by the first subcooled electronic expansion valve (31) and enters the first economizer (32). It exchanges heat with the refrigerant in the main circulation loop in the first economizer (32). Then, under the action of pressure difference, it is injected into the intermediate pressure chamber of the compressor (1) through the first injection pipe (33). In high-efficiency heating mode: the high-temperature gaseous refrigerant discharged by the compressor (1) passes through the oil separator (2), four-way valve (3), gas pipe shut-off valve (10), second branch pipe (9) and first solenoid valve (14) and enters the heat exchanger (15) to exchange heat with water. The refrigerant that releases heat passes through the first electronic expansion valve (13), first branch pipe (8) and liquid pipe shut-off valve (7), enters the first economizer (32) and liquid tank (6), and enters the main electronic expansion valve (5) for throttling. The throttled refrigerant enters the outdoor heat exchanger (4), where the refrigerant exchanges heat with the air. After absorbing heat, the refrigerant passes through the four-way valve (3) and then enters the gas-liquid separator (11), and finally returns to the compressor (1) to complete the heating cycle. During this process, the second subcooled electronic expansion valve (41) opens, and the hot water in the energy storage tank (21) is pumped to the second economizer (42) by the second water pump (43). The refrigerant and hot water in the second subcooled electronic expansion valve (41) and the second economizer (42) exchange heat. The refrigerant that absorbs heat is injected into the intermediate pressure chamber of the compressor (1) through the second injection pipe (44).

7. The method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" energy storage as described in claim 6, characterized in that: After startup, in heating mode, the unit determines the operating mode based on the set conditions. When there is no heat load demand, the heat pump is in standby mode and is driven by a photovoltaic power generation system to operate in full heat storage mode. In this operating mode, the mains power is cut off and the compressor (1) is driven by solar power generation to do work and store heat. When the unit receives a heating operation command, it will operate in heating mode according to the principle of preferred heating operation. After the set operation time, it will make a judgment. If the following conditions are met at the same time, it will operate in partial heat storage mode, that is, while heating to produce hot water, it will also operate in partial heat storage mode. 1) Outdoor ambient temperature Tao > T ao,s3 , T ao,s3 Set the temperature for the user; 2) The current water temperature in the energy storage tank (21) is higher than the set water temperature T for heat storage. tank,set2 Low setting value 1, T tank,cur < T tank,set2 -Set value 1; 3) Temperature T of the hot water generated by the heat pump w,out <T set,h +Set value 2; 4) The power output of solar photovoltaic power generation is more than 1% higher than the actual operating power of the unit; 5) Compressor (1) Current operating frequency INV_F cur < (1-ζ) h )×INV_F max INV_F max The maximum operating frequency set in the controller; ζ h For the heat storage ratio, ζ h =Q h,s / Q h Q h The rated cooling capacity of the unit. In the formula: ρ and C p The density of water is 1000 kg / m³. 3 Specific heat 4180 J / kg·℃; T h,0 T represents the water temperature in the energy storage tank (21) before the machine starts heating in winter. h,tar The target temperature for heat storage can be set customizable in the unit control program.

8. The method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" as described in claim 7, characterized in that: During partial heat storage mode operation, partial heat storage will stop and switch to conventional heating mode when one of the following conditions is met. 1) Outdoor ambient temperature Tao <Tao,s4, T ao,s4 Set the temperature for the user; 2) The current water temperature in the energy storage tank (21) is higher than the set water temperature for cold storage, i.e., T tank,cur > T tank,set2 +Set value 2; 3) The power generated by solar photovoltaic power generation is less than 2% of the actual operating power.

9. The method for realizing a multi-energy complementary heat pump with dual cooling and heating storage based on "photovoltaic-storage-direct-flexible" as described in claim 8, characterized in that: When the unit detects the current water temperature T in the energy storage tank (21) tank,cur >T inj,out When the set value is 1, the second water pump (43) runs and the second subcooled electronic expansion valve (41) opens to a certain degree to perform active jet enthalpy enhancement. When T tank,cur < T inj,out At this time, the second water pump (43) stops running and the second subcooled electronic expansion valve (41) closes; If the current water temperature T in the energy storage tank (21) is inj,out ≤T tank,cur ≤T inj,out +Set value 1, the unit maintains the current operating mode.

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