A multi-mode air source heat pump system based on photovoltaic direct drive

Abstract

The utility model discloses a kind of multi-modal air source heat pump systems based on photovoltaic direct drive, including refrigerant circulation system, water circulation system and production / power supply system;Refrigerant circulation system includes compressor, electric three-way valve, T-shaped three-way pipe, check valve, refrigerant / air heat exchanger, refrigerant / water heat exchanger, four-way valve, main electronic expansion valve, enthalpy-increasing electronic expansion valve, filter, economizer, liquid storage tank;Water circulation system includes heating and refrigeration system and hot water system, heating and refrigeration system includes first water pump, second water pump, energy storage water tank, circulating pipeline, differential pressure bypass valve, indoor terminal, exhaust valve;Hot water system includes hot water storage tank, circulating pipeline, water mixing valve, and heat exchanger connected with refrigerant circulation system is equipped in hot water storage tank;Production / power supply system includes photovoltaic array, direct current MPPT control converter, ac-dc inverter;Adopt photovoltaic direct drive, multi-modal joint mode, practical, pollution-free, heating stability, reduce environmental pollution and energy consumption.

Description

Technical Field

[0001] This utility model belongs to the field of air source heat pump technology, specifically relating to a multi-modal air source heat pump system based on photovoltaic direct drive. Background Technology

[0002] With societal progress and improved living standards, people's demands for comfortable living environments are increasing, as are their requirements for central air conditioning functions. From simple air conditioning for cooling and heating, the current demand for integrated air conditioning and hot water systems has evolved. Especially in northern my country, heating has become indispensable for most families. In recent years, air source heat pump systems have seen significant development. However, these systems cannot freely switch between cooling, heating, and hot water modes. Typically, two separate systems are needed to achieve heating, cooling, and hot water production: one for heating and cooling, and another for hot water. This not only increases costs but also requires a large footprint. Systems using domestic hot water in cooling mode are complex and cannot effectively recover and utilize the heat generated in cooling mode, often resulting in a heavy compressor load that fails to reach the ideal hot water temperature. The complex structure also increases user costs. Furthermore, existing air source tri-generation units, when reaching the set temperature in heating or cooling mode, cannot circulate excess heat to the domestic hot water system for reuse, leading to energy waste. Air source heat pump systems are generally powered by the municipal power grid. Since there is no combustion process, they do not cause pollution emissions to the surrounding environment. However, they still consume a lot of mains electricity during long-term operation, and cannot achieve the effect of energy saving.

[0003] Solar energy, as one of the renewable energy sources strongly promoted by China, possesses numerous advantages, including its universality, safety, sustainability, and enormous potential. It is an inexhaustible energy source, and its significant economic benefits have led to its widespread application in production and daily life.

[0004] For example, Chinese invention patent application number CN202211570509.0 discloses a photovoltaic direct-drive air conditioning system and its operation control method. This photovoltaic direct-drive air conditioning system includes a photovoltaic array, a first energy router, a second energy router, and a photovoltaic direct-drive air conditioner. The first energy router includes a sensor, a main control module, and a DC-DC conversion module. The output terminal of the photovoltaic array is connected to the input terminal of the DC-DC conversion module, the output terminal of the DC-DC conversion module is connected to the input terminal of the second energy router, and the output terminal of the second energy router is connected to the photovoltaic direct-drive air conditioner. The output terminal of the DC-DC conversion module is connected to the input terminal of the sensor, the output terminal of the sensor is connected to the input terminal of the main control module, and the output terminal of the main control module is connected to the control terminal of the DC-DC conversion module. This solution addresses the problem that existing photovoltaic direct-drive air conditioning systems sample the voltage and current values ​​output by the photovoltaic array, leading to a complex system structure.

[0005] For example, Chinese utility model patent application CN201720426920.9 discloses a solar photovoltaic and solar thermal integrated air source heat pump heating system, including a compressor, compressor terminal, high-pressure protector, four-way reversing valve, solenoid valve, water tank, third solenoid valve, solar photovoltaic thermal panel, first variable frequency water pump, phase change heat storage device, second variable frequency water pump, electronic expansion valve, evaporator, low-pressure protector, fourth solenoid valve, and photovoltaic module. When solar radiation intensity is high, this system generates electricity to power the heat pump unit and produces hot water for users' heating or domestic hot water needs. When solar radiation intensity is low, the air source heat pump is used as the primary heating method, while the heat generated by solar energy is stored in the phase change heat storage device as a low-temperature heat source in the air source heat pump's defrosting mode to defrost the evaporator. This avoids the water temperature fluctuations caused by using hot water in the water tank as a low-temperature heat source during reverse circulation defrosting in traditional systems, thereby improving the overall utilization performance of the system.

[0006] None of the above-mentioned existing technologies simultaneously possess the functions of cooling, heating, and hot water supply, and do not fully utilize solar energy. Therefore, this application provides a multi-modal air source heat pump system based on photovoltaic direct drive. Summary of the Invention

[0007] This invention addresses the shortcomings of existing technologies by providing a multimodal air source heat pump system based on photovoltaic direct drive.

[0008] The multimodal air source heat pump system includes a refrigerant circulation system, a water circulation system, and a power generation / distribution system; wherein,

[0009] The refrigerant circulation system includes a compressor, an electric three-way valve, a T-type three-way pipe, a check valve, a refrigerant / air heat exchanger, a refrigerant / water heat exchanger, a four-way valve, a main electronic expansion valve, an enthalpy-increasing electronic expansion valve, a filter, an economizer, and a liquid receiver.

[0010] The compressor's exhaust port is connected in sequence to port A of the electric three-way valve, port B of the electric three-way valve, the T-type three-way pipe, and the inlet of the four-way valve through pipelines. The middle outlet of the four-way valve is connected to the compressor's air inlet through the compressor's gas-liquid separator. Port C of the electric three-way valve is connected to the inlet of the hot water storage tank heat exchanger, and the middle port of the T-type three-way pipe is connected to the outlet of the hot water storage tank heat exchanger.

[0011] The left port of the four-way valve is connected in sequence to the refrigerant / air heat exchanger, the distributor head, the second check valve, the liquid receiver, the economizer, and the filter. The filter outlet is divided into two paths: one path is connected to the enthalpy-increasing port of the compressor via the enthalpy-increasing electronic expansion valve and the economizer, and the other path is connected to the right port of the four-way valve via the main electronic expansion valve, the third check valve, and the refrigerant / water heat exchanger.

[0012] The water circulation system includes a heating and cooling system and a hot water system. The heating and cooling system includes a first water pump, a second water pump, a storage tank, circulation pipelines, a differential pressure bypass valve, indoor terminals, and an air vent valve. The storage tank is connected to the first and second water pumps through pipelines. The hot water system includes a hot water storage tank, circulation pipelines, and a mixing valve. The hot water storage tank is equipped with a heat exchanger connected to the refrigerant circulation system.

[0013] The power generation / supply system includes a photovoltaic array, a DC MPPT control converter, and an AC / DC inverter. The photovoltaic array is connected to the DC MPPT control converter, and the municipal power grid is connected to the AC / DC inverter. The outputs of the DC MPPT control converter and the AC / DC inverter are combined and then connected to the compressor, fan, electric three-way valve, four-way valve, enthalpy-increasing electronic expansion valve, main electronic expansion valve, and the first and second water pumps.

[0014] Furthermore, the compressor is a DC inverter compressor, and the compressor type includes any one of rotary, scroll, or reciprocating types.

[0015] Furthermore, the refrigerant / water heat exchanger can be any one of the following: flat plate, spiral plate, plate-fin, submerged spiral tube, shell-and-tube, or tube-and-plate type.

[0016] Furthermore, the main electronic expansion valve and the enthalpy-increasing electronic expansion valve are configured as either a thermostatic expansion valve or a capillary tube.

[0017] Furthermore, the indoor terminals of the heating and cooling system are one or more of the following: fan coil units, radiators, or underfloor heating pipes.

[0018] Furthermore, the heat exchanger of the hot water storage tank is any one of the following: an inner tank outer disc microchannel heat exchanger, an external copper coil heat exchanger, an internal copper coil heat exchanger, or an internal stainless steel coil heat exchanger.

[0019] Furthermore, the energy storage tank is equipped with a pressure gauge, an expansion tank, and an air vent.

[0020] Furthermore, the power generation / supply system prioritizes the power generated by the photovoltaic array. When the photovoltaic array's power generation is insufficient, the municipal power grid supplements the power supply via AC / DC inverters.

[0021] Furthermore, a differential pressure bypass valve is installed between the system's supply and return water mains to maintain stable differential pressure at key system points and ensure the minimum flow rate through core equipment.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] 1. The multi-modal air source heat pump system based on photovoltaic direct drive described in this utility model realizes flexible switching between three modes: cooling, heating, and hot water production through the integrated design of electric three-way valve and T-type three-way pipe in the refrigerant circulation system. When cooling, the refrigerant directly enters the four-way valve through port B of the electric three-way valve, and when producing hot water, it enters the heat exchanger of the hot water storage tank through port C. There is no need to configure two additional heat exchange systems, which greatly simplifies the system structure and reduces equipment costs and installation space requirements.

[0024] 2. The multi-mode air source heat pump system based on photovoltaic direct drive described in this utility model realizes photovoltaic direct drive through a photovoltaic array + DC MPPT control converter + AC / DC inverter. The DC power generated by the photovoltaic array is directly used to power core components such as compressor and fan after being controlled by MPPT. When insufficient, it is supplemented by the municipal power grid. The photovoltaic power is given priority to use, which reduces the energy loss in the municipal power grid conversion link, improves the overall energy efficiency ratio of the system, and reduces the indirect carbon emissions caused by traditional power grid supply.

[0025] 3. The multi-modal air source heat pump system based on photovoltaic direct drive described in this utility model achieves cascade utilization of cold and heat through the design of the water circulation system. During the cooling season, the low-grade cooling energy after the indoor terminal fan coil units absorb heat can be preferentially used for fresh air cooling, and the remaining cooling energy can be used for radiant terminals, thereby improving the utilization rate of cooling energy. During the heating season, the low-grade heat energy after preheating domestic hot water can be used to heat fresh air, avoiding the waste of high-temperature heat energy. The non-cooling / heating system only operates in hot water production mode, making full use of the low-grade heat energy absorbed by the air source heat pump to heat domestic hot water, avoiding equipment idleness.

[0026] 4. The multi-modal air source heat pump system based on photovoltaic direct drive described in this utility model improves the heating capacity of the compressor at low temperatures and expands the system's applicability by setting an enthalpy-increasing electronic expansion valve and an economizer in the refrigerant circulation. In low-temperature environments, part of the refrigerant enters the economizer through the enthalpy-increasing electronic expansion valve to absorb heat, and then replenishes the compressor's enthalpy-increasing port.

[0027] 5. The multi-modal air source heat pump system based on photovoltaic direct drive described in this utility model uses a differential pressure bypass valve to maintain a stable differential pressure at key points between the supply and return water mains of the water circulation system, ensuring the minimum flow rate of core equipment under low load conditions and preventing equipment damage or system failure due to insufficient flow. The energy storage tank buffers the heat exchange fluctuations between the refrigerant and water, the pressure gauge monitors the pressure in real time, the expansion tank balances system pressure changes, and the exhaust valve discharges gas from the pipeline, all of which together ensure the stable operation of the water circulation system. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the photovoltaic direct-drive multimodal air source heat pump system.

[0029] Figure 2 A schematic diagram of the operation of the photovoltaic direct-drive multimodal air source heat pump system that combines cooling and hot water modes;

[0030] Figure 3 This is a schematic diagram of the operation of the multimodal air source heat pump system based on photovoltaic direct drive, which also supports both heating and hot water modes.

[0031] Figure 4 This is a schematic diagram of the operation of the photovoltaic direct-drive-based multimodal air source heat pump system in hot water only mode during the non-cooling and heating seasons.

[0032] Figure 5 for Figures 1 to 4 Schematic diagram of a check valve;

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Compressor; 2. Electric three-way valve; 3. T-type three-way pipe; 4. Check valve; 5. Refrigerant / air heat exchanger; 6. Refrigerant / water heat exchanger; 7. Four-way valve; 8. Main electronic expansion valve; 9. Enthalpy-increasing electronic expansion valve; 10. Filter; 11. Economizer; 12. Liquid receiver; 13. Hot water storage tank; 14. Distributor; 15. First water pump; 16. Second water pump; 17. Energy storage tank; 19. Differential pressure bypass valve; 21. Air vent valve; 22. Mixing valve; 23. Heat exchanger; 24. Photovoltaic array; 25. DC MPPT control converter; 26. AC / DC inverter; 27. Fan; 28. Fan coil unit; 29. ​​Radiator; 30. Underfloor heating pipe; 31. Pressure gauge; 32. Expansion tank; 33. Air vent valve; 111. First check valve; 112. Second check valve; 113. Third check valve; 114. Fourth check valve. Detailed Implementation

[0035] The following describes in detail, with reference to the accompanying drawings, specific embodiments of the multimodal air source heat pump system based on photovoltaic direct drive described in this utility model. Example

[0036] like Figure 1 As shown, the multimodal air source heat pump system includes a refrigerant circulation system, a water circulation system, and a power generation / distribution system; wherein,

[0037] The refrigerant circulation system includes a compressor 1, an electric three-way valve 2, a T-type three-way pipe 3, a check valve 4, a refrigerant / air heat exchanger 5, a refrigerant / water heat exchanger 6, a four-way valve 7, a main electronic expansion valve 8, an enthalpy-increasing electronic expansion valve 9, a filter 10, an economizer 11, and a liquid receiver 12, etc. Figure 5 As shown, the one-way valve 4 includes a first one-way valve 111, a second one-way valve 112, a third one-way valve 113, and a fourth one-way valve 114;

[0038] The exhaust port of compressor 1 is connected in sequence to port A of electric three-way valve 2, port B of electric three-way valve 2, T-type three-way pipe 3 and the inlet of four-way valve 7 through pipelines. The middle outlet of four-way valve 7 is connected to the air inlet of compressor 1 through the gas-liquid separator of compressor 1. Port C of electric three-way valve 2 is connected to the inlet of heat exchanger of hot water storage tank 13, and the middle port of T-type three-way pipe 3 is connected to the outlet of heat exchanger of hot water storage tank 13.

[0039] The left port of the four-way valve 7 is connected in sequence to the refrigerant / air heat exchanger 5, the liquid distributor 14, the second check valve 112, the liquid storage tank 12, the economizer 11, and the filter 10. The outlet of the filter 10 is divided into two paths: one path is connected to the enthalpy-increasing port of the compressor 1 via the enthalpy-increasing electronic expansion valve 9 and the economizer 11; the other path is connected to the right port of the four-way valve 7 via the main electronic expansion valve 8, the third check valve 113, and the refrigerant / water heat exchanger 6.

[0040] The water circulation system includes a heating and cooling system and a hot water system. The heating and cooling system includes a first water pump 15, a second water pump 16, a storage tank 17, circulation pipelines, a differential pressure bypass valve 19, indoor terminals, and an air vent valve 21. The storage tank 17 is connected to the first water pump 15 and the second water pump 16 through pipelines. The hot water system includes a hot water storage tank 13, circulation pipelines, and a mixing valve 22. The hot water storage tank 13 is equipped with a heat exchanger 23 that is connected to the refrigerant circulation system.

[0041] The power generation / supply system includes a photovoltaic array 24, a DC MPPT control converter 25, and an AC / DC inverter 26. The photovoltaic array 24 is connected to the DC MPPT control converter 25, and the municipal power grid is connected to the AC / DC inverter 26. The outputs of the DC MPPT control converter 25 and the AC / DC inverter 26 are combined and connected to the compressor 1, the fan 27, the electric three-way valve 2, the four-way valve 7, the main electronic expansion valve 8, the enthalpy-increasing electronic expansion valve 9, and the first water pump 15 and the second water pump 16.

[0042] Furthermore, compressor 1 is a DC inverter compressor, and compressor 1 type includes any one of rotary, scroll or piston type.

[0043] Furthermore, the refrigerant / water heat exchanger 6 can be any one of the following types: flat plate, spiral plate, plate-ribbed, submerged spiral tube, shell-and-tube, or tube-and-plate.

[0044] Furthermore, the main electronic expansion valve 8 and the enthalpy-increasing electronic expansion valve 9 can also be configured as thermal expansion valves or capillary tubes;

[0045] The main electronic expansion valve 8 is usually located at the inlet end of the refrigerant / water heat exchanger 6. Its function is to regulate the refrigerant flow rate entering the refrigerant / water heat exchanger 6 to match the water-side load, thereby avoiding the risk of reduced heat exchange efficiency or liquid carryover in the compressor suction due to excessive or insufficient refrigerant. If the main electronic expansion valve 8 is replaced with a thermostatic expansion valve, the flow rate is adaptively adjusted. The refrigerant flow rate is dynamically adjusted according to the superheat of the evaporator outlet to ensure that the refrigerant in the evaporator is fully evaporated, avoiding liquid slugging or overheating. This simplifies the control logic, eliminates the need for an external power supply or controller, and can operate solely based on a physical temperature sensor. It is suitable for scenarios where cost is sensitive or control accuracy requirements are not high.

[0046] If the main electronic expansion valve 8 is replaced with a capillary tube, there are no moving parts, and the throttling is based solely on the physical structure. There is almost no maintenance required, making it suitable for small systems with stable operating conditions. The throttling effect of the capillary tube is uniquely determined by its length and inner diameter. It needs to be precisely selected according to the system design, such as the compressor displacement and the evaporator / condenser capacity. If the selection is appropriate, the refrigerant flow can be stably controlled.

[0047] The enthalpy-increasing electronic expansion valve 9 is located at the outlet end of the economizer 11. Its function is to regulate the flow rate of refrigerant entering the enthalpy-increasing port of the compressor 1. By supplementing low-temperature and low-pressure refrigerant gas, the suction volume of the compressor 1 is increased, thereby enhancing the heating capacity in low-temperature environments.

[0048] If the enthalpy-increasing electronic expansion valve 9 is replaced with a thermostatic expansion valve, the thermostatic expansion valve can sense the temperature of the refrigerant at the economizer outlet and adjust the refrigerant flow rate supplied to the compressor, avoiding compressor liquid slugging due to excessive gas supply or insufficient enthalpy-increasing effect due to insufficient gas supply. If the enthalpy-increasing electronic expansion valve 9 is replaced with a capillary tube, the capillary tube provides a stable gas supply refrigerant flow rate to the economizer through a fixed throttling effect, which is suitable for scenarios with clearly defined design conditions, such as when the minimum winter temperature in the target area is stable above -10℃.

[0049] Furthermore, the indoor terminal of the heating and cooling system is one or more of the following: fan coil unit 28, radiator 29, or underfloor heating pipe 30.

[0050] Furthermore, the heat exchanger 23 of the hot water storage tank 13 is any one of the following: an inner tank outer disc microchannel heat exchanger, an external copper coil heat exchanger, an internal copper coil heat exchanger, or an internal stainless steel coil heat exchanger.

[0051] Furthermore, the energy storage tank 17 is equipped with a pressure gauge 31, an expansion tank 32, and an air vent valve 33;

[0052] Among them, pressure gauge 31 displays the water pressure status in energy storage tank 17 and water circulation system in real time; expansion tank 32 absorbs the volume expansion or contraction caused by temperature changes in water circulation system to maintain system pressure stability; exhaust valve 33 automatically or manually discharges dissolved air or free air in water circulation system to avoid air resistance.

[0053] Furthermore, the DC power generated by the photovoltaic array 24 is processed by the DC MPPT control converter 25 and then used to power the compressor 1, fan 27, etc. The power generation / power supply system prioritizes the power generated by the photovoltaic array 24. When the power generation of the photovoltaic array 24 is insufficient, the municipal power grid provides supplementary power through the AC / DC inverter 26.

[0054] Furthermore, the differential pressure bypass valve 29 is installed between the system's supply and return water mains to maintain stable differential pressure at key system points and ensure the minimum flow rate through the core equipment.

[0055] Specifically, such as Figure 2 As shown, during the cooling season, a cooling and hot water mode is adopted. When producing hot water, the high-temperature and high-pressure refrigerant supplied by compressor 1 enters the hot water storage heat exchanger through ports A and C of the electric three-way valve 2 to heat the cold water in the hot water storage tank 13. Then, it enters the lower port of the four-way valve 7 through the middle port and outlet of the T-shaped three-way pipe 3. When cooling, the high-temperature and high-pressure refrigerant supplied by compressor 1 directly enters the lower port of the four-way valve 7 through ports A and B of the electric three-way valve 2. The switching is convenient, and hot water can be heated first before sunrise or during off-peak electricity hours at night, saving energy costs.

[0056] Cooling process: Indoor fan coil unit 28 absorbs indoor heat and cools the room. Second water pump 16 circulates water into energy storage tank 17. First water pump 15 circulates water and exchanges heat with the refrigerant in refrigerant / water heat exchanger 6. After absorbing heat, the refrigerant enters from the right port of four-way valve 7 and exits from the middle port of four-way valve 7. It then enters compressor 1 through the air inlet of compressor 1. Compressor 1 pressurizes and heats the refrigerant. It releases heat through indoor refrigerant / air heat exchanger 5 and flows through distributor head 14, second one-way valve 112, liquid storage tank 12, economizer 11, filter 10, and main electronic expansion valve 9 to reduce pressure and temperature. It then returns to refrigerant / water heat exchanger 6 through third one-way valve 113 to exchange heat with circulating water and cool the water.

[0057] like Figure 3As shown, during the heating season, a heating and hot water mode is adopted. When producing hot water, the high-temperature and high-pressure refrigerant supplied by compressor 1 enters the hot water storage heat exchanger through ports A and C of the electric three-way valve 2 to heat the cold water in the hot water storage tank 13, and then enters the lower port of the four-way valve 7 through the middle port and outlet of the T-shaped three-way pipe 3. When producing heat, the high-temperature and high-pressure refrigerant supplied by compressor 1 directly enters the lower port of the four-way valve 7 through ports A and B of the electric three-way valve 2. The switching is convenient, and hot water can be heated first before sunrise or during off-peak electricity hours at night, saving energy costs.

[0058] Heating process: In refrigerant / air heat exchanger 6, the refrigerant absorbs the low-temperature heat source from the outdoor air, evaporates after absorbing heat, and the low-temperature, low-pressure gaseous refrigerant enters through the left port and exits through the middle port of four-way valve 7, enters compressor 1 through the air inlet, compressor 1 compresses and heats the refrigerant, and the high-temperature, high-pressure gaseous refrigerant exits from the exhaust port of compressor 1, enters the lower port of four-way valve 7 through ports A and B of electric three-way valve 2, exits through the right port of four-way valve 7, and enters refrigerant / water heat exchanger 6, where the refrigerant releases heat and condenses, heating the heating water. The medium-temperature, high-pressure liquid refrigerant passes through the first one-way valve 111, the liquid storage tank 12, the economizer 11, and the filter 10. Most of the refrigerant passes through the main electronic expansion valve 8, where it is throttled, its pressure and temperature are reduced. The low-temperature, low-pressure liquid refrigerant passes through the fourth one-way valve 114 and the distributor 14, returning to the evaporator refrigerant / air heat exchanger 5. A small portion of the refrigerant passes through the enthalpy-increasing electronic expansion valve 9, enters the economizer 11, absorbs some heat, and enters the compressor 1 to replenish gas, thereby improving the compressor 1's heating capacity in low-temperature environments.

[0059] Heating hot water enters the energy storage tank 17 under the drive of the first water pump 15, and then enters the indoor heating terminal fan coil unit 28 via the second water pump 16. The radiators 29 / floor heating pipes 30 heat the room. After heat dissipation, the cold water circulates back to the energy storage tank 17 and returns to the refrigerant / water heat exchanger 6 via the first water pump 15 for heating.

[0060] like Figure 4 As shown, during non-cooling and non-heating seasons, the hot water mode is used:

[0061] Heating process:

[0062] In the refrigerant / air heat exchanger 5, the refrigerant absorbs the low-temperature heat source from the outdoor air, evaporates after absorbing heat, and the low-temperature, low-pressure gaseous refrigerant enters through the left port and exits through the middle port of the four-way valve 7. It enters the compressor 1 through the air inlet of the compressor 1, where the compressor 1 compresses and heats the refrigerant. The high-temperature, high-pressure gaseous refrigerant exits through the exhaust port of the compressor 1, enters the heat exchanger of the hot water storage tank 13 through the A and C ports of the electric three-way valve 2, and heats the water in the hot water storage tank 13. From the heat exchanger outlet of the hot water storage tank 13, it enters the lower port of the four-way valve 7 through the middle port of the T-type three-way valve 3, exits through the right port of the four-way valve 7, and enters the refrigerant / water heat exchanger 6. It then passes through the first one-way valve 111, the liquid storage tank 12, the economizer 11, and the filter 10. The refrigerant passes through the main electronic expansion valve 8, where it is throttled, depressurized, and cooled. The low-temperature, low-pressure liquid refrigerant returns to the evaporator refrigerant / air heat exchanger 5 through the fourth one-way valve 114 and the distributor 14.

[0063] This utility model adopts a photovoltaic direct drive and multi-modal combination method, which can not only meet the requirements of energy saving, practicality and pollution-free, but also ensure the stability of heating and meet the requirements of long-term heating, cooling and hot water circulation, so as to reduce the environmental pollution and energy consumption caused by traditional heating.

[0064] The multi-modal air source heat pump system based on photovoltaic direct drive described in this utility model has high energy utilization efficiency. The electrical part of the air source heat pump system can be directly driven by photovoltaics, which reduces energy loss in intermediate links and improves the overall energy efficiency of the system.

[0065] The multi-modal air source heat pump system based on photovoltaic direct drive described in this utility model has the function of cascade utilization of cold and heat. The air source heat pump system has high energy efficiency. In the heating season, the low-grade heat energy after preheating domestic hot water is used to heat fresh air. In the cooling season, the air source heat pump system prioritizes the use of high-grade cooling energy for radiant terminals, and then uses the low-grade cooling energy after the radiant terminals are used for fresh air cooling, thereby improving the overall energy efficiency of the air source heat pump system.

[0066] The multi-modal air source heat pump system based on photovoltaic direct drive described in this utility model has high integration, small footprint, and low cost. The liquid circulation system is equipped with a first three-way solenoid valve and a second three-way solenoid valve, which can freely switch between cooling mode, heating mode, and hot water mode. The hot water mode is switched according to the temperature change of the water in the insulation box, so as to provide hot water continuously.

[0067] The preferred embodiments of this utility model are not intended to limit the utility model. Any modifications, equivalent substitutions, and improvements made within the concept and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A multimodal air source heat pump system based on photovoltaic direct drive, characterized in that, This includes a refrigerant circulation system, a water circulation system, and a power generation / supply system; among which, The refrigerant circulation system includes a compressor, an electric three-way valve, a T-type three-way pipe, a check valve, a refrigerant / air heat exchanger, a refrigerant / water heat exchanger, a four-way valve, a main electronic expansion valve, an enthalpy-increasing electronic expansion valve, a filter, an economizer, and a liquid receiver. The compressor's exhaust port is connected in sequence to port A of the electric three-way valve, port B of the electric three-way valve, T-type three-way pipe, and the inlet of the four-way valve through pipelines. The middle outlet of the four-way valve is connected to the compressor's air inlet through the compressor's gas-liquid separator. Port C of the electric three-way valve is connected to the inlet of the hot water storage tank heat exchanger, and the middle port of the T-type three-way pipe is connected to the outlet of the hot water storage tank heat exchanger. The left port of the four-way valve is connected in sequence to the refrigerant / air heat exchanger, the distributor head, the second check valve, the liquid receiver, the economizer, and the filter. The filter outlet is divided into two paths: one path is connected to the enthalpy-increasing port of the compressor via the enthalpy-increasing electronic expansion valve and the economizer, and the other path is connected to the right port of the four-way valve via the main electronic expansion valve, the third check valve, and the refrigerant / water heat exchanger. The water circulation system includes a heating and cooling system and a hot water system. The heating and cooling system includes a first water pump, a second water pump, a storage tank, circulation pipelines, a differential pressure bypass valve, indoor terminals, and an air vent valve. The storage tank is connected to the first and second water pumps through pipelines. The hot water system includes a hot water storage tank, circulation pipelines, and a mixing valve. The hot water storage tank is equipped with a heat exchanger connected to the refrigerant circulation system. The power generation / supply system includes a photovoltaic array, a DC MPPT control converter, and an AC / DC inverter. The photovoltaic array is connected to the DC MPPT control converter, and the municipal power grid is connected to the AC / DC inverter. The outputs of the DC MPPT control converter and the AC / DC inverter are combined and then connected to the compressor, fan, electric three-way valve, four-way valve, main electronic expansion valve, enthalpy-increasing electronic expansion valve, and the first and second water pumps.

2. The multi-modal air source heat pump system based on photovoltaic direct drive according to claim 1, characterized in that, The compressor is a DC inverter compressor, and the compressor type includes any one of rotary, scroll, or reciprocating types.

3. The multi-modal air source heat pump system based on photovoltaic direct drive according to claim 1, characterized in that, The refrigerant / water heat exchanger can be any one of the following types: flat plate, spiral plate, plate-fin, submerged spiral tube, shell-and-tube, or tube-and-plate.

4. The multi-modal air source heat pump system based on photovoltaic direct drive according to claim 1, characterized in that, The main electronic expansion valve and the enthalpy-increasing electronic expansion valve are configured as either a thermostatic expansion valve or a capillary tube.

5. The multi-modal air source heat pump system based on photovoltaic direct drive according to claim 1, characterized in that, The indoor terminals of the heating and cooling system are one or more of the following: fan coil units, radiators, or underfloor heating pipes.

6. The multi-modal air source heat pump system based on photovoltaic direct drive according to claim 1, characterized in that, The heat exchanger of the hot water storage tank is any one of the following: an inner tank outer disc microchannel heat exchanger, an external copper coil heat exchanger, an internal copper coil heat exchanger, or an internal stainless steel coil heat exchanger.

7. The multi-modal air source heat pump system based on photovoltaic direct drive according to claim 1, characterized in that, The energy storage tank is equipped with a pressure gauge, an expansion tank, and an air vent valve.

8. The multi-modal air source heat pump system based on photovoltaic direct drive according to claim 1, characterized in that, The power generation system prioritizes the use of electricity generated by the photovoltaic array. When the photovoltaic array's power generation is insufficient, the municipal power grid provides supplementary power through AC / DC inverters.

9. The multi-modal air source heat pump system based on photovoltaic direct drive according to claim 1, characterized in that, The differential pressure bypass valve is installed between the system's supply and return water mains to maintain stable differential pressure at key system points and ensure minimum flow through core equipment.

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