Novel solar coupling air-water double-source heat pump system based on thermal diode

Abstract

According to the novel solar coupling air-water double-source heat pump system based on the thermal diode, heat supply network circulating water exchanges heat with the heat pump working medium in the air-water double-source heat pump condenser, one part of the cooled heat pump working medium enters the thermal diode and exchanges heat with hot water from a solar PVT plate, and the other part of the cooled heat pump working medium enters the thermal diode and exchanges heat with the hot water from the solar PVT plate. The heated heat pump working medium enters a compressor, the other part of the heat pump working medium enters an air-water double-source heat pump evaporator and is heated by an air source or a water source, and the heated heat pump working medium enters the compressor and is mixed with the heat pump working medium output by a heat diode for boosting; the heated and pressurized heat pump working medium enters an air-water double-source heat pump condenser to continue to exchange heat with heat supply network circulating water; the heat supply system is particularly suitable for running under complex and changeable weather conditions, and can be widely applied to the fields of heat supply in cold regions, industrial and agricultural hot water supply and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of cogeneration, and in particular relates to a novel solar-coupled air-water dual-source heat pump system based on thermal diodes. Background Art

[0002] With the intensification of the global energy crisis and the increasing demand for low-carbon environmental protection, the multi-energy complementary system of heating, cooling and electricity supply has gradually become an important development direction in the field of energy utilization. Traditional heating systems usually rely on a single energy source, such as coal, natural gas or electricity. This method not only has low energy utilization efficiency, but is also easily affected by energy price fluctuations and unstable supply. In addition, in areas with complex climatic conditions, the operating efficiency of the heating system is often limited by changes in ambient temperature. Especially in cold areas or on cloudy days, the energy efficiency of the heating system drops significantly, making it difficult to meet the heating needs of users.

[0003] In recent years, solar energy, as a renewable and clean energy source, has been increasingly used in the field of heating. Solar photovoltaic-thermoelectric (PVT) modules can not only provide clean electricity, but also provide heat sources for heat pumps through photothermal conversion. However, solar energy resources are intermittent and volatile, and heating systems that rely solely on solar energy still have deficiencies in the stability of energy supply. Therefore, a coupled heating system combining multiple heat sources, such as air source heat pumps and water source heat pumps, can achieve a more stable energy supply. However, the design of existing multi-source heat pump systems still has technical bottlenecks in terms of heat source switching efficiency and heat energy transfer losses. Especially in cold weather conditions, how to achieve efficient utilization and switching of heat sources is still a technical problem. Summary of the invention

[0004] The purpose of the present invention is to provide a novel solar-coupled air-water dual-source heat pump system based on thermal diodes, which solves the defects of low switching efficiency and large heat loss in existing multi-source heat pump systems during heating.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: The present invention provides a novel solar-coupled air-water dual-source heat pump system based on a thermal diode, comprising a solar PVT panel, a thermal diode, an air preheater, an air-water dual-source heat pump evaporator and an air-water dual-source heat pump condenser, wherein: The heat pump working medium outlet of the air-water dual-source heat pump condenser is divided into two paths, one of which is connected to the heat pump working medium inlet of the thermal diode, and the other is connected to the heat pump working medium inlet of the air-water dual-source heat pump evaporator; the heat pump working medium outlet of the thermal diode and the heat pump working medium outlet of the air-water dual-source heat pump evaporator are both connected to the heat pump working medium inlet of the air-water dual-source heat pump condenser; The water supply circulating water inlet of the air-water dual-source heat pump condenser is connected to the return water pipeline of the heating network, and the water supply circulating water outlet of the air-water dual-source heat pump condenser is connected to the water supply pipeline of the heating network; The water source inlet of the thermal diode is connected to the hot water outlet of the solar PVT panel, and the water source outlet of the thermal diode is connected to the hot water inlet of the solar PVT panel; The air-water dual-source heat pump evaporator comprises an air source evaporator and a water source evaporator, wherein the inlet of the air source evaporator is connected to an air preheater; the water working medium inlet of the water source evaporator is connected to the water source outlet of the thermal diode, and the water working medium outlet of the water source evaporator is connected to the water source inlet of the thermal diode.

[0006] Preferably, the thermal diode comprises an evaporation section and a condensation section, wherein the evaporation section is provided with a water source inlet, a water source outlet, a thermal diode working medium inlet and a thermal diode working medium outlet, the water source inlet is respectively connected to the hot water outlet of the solar PVT panel and the water working medium outlet of the water source evaporator, and the water source outlet is respectively connected to the hot water inlet of the solar PVT panel and the water working medium inlet of the water source evaporator; The condensing section is provided with a heat pump working fluid inlet, a heat pump working fluid outlet, a thermal diode working fluid inlet and a thermal diode working fluid outlet. The heat pump working fluid inlet and outlet are respectively connected to the heat pump working fluid outlet and inlet of the air-water dual-source heat pump condenser; the thermal diode working fluid inlet and outlet are respectively connected to the thermal diode working fluid outlet and inlet on the evaporating section.

[0007] Preferably, a first water pump is provided between the hot water outlet of the solar PVT panel and the water source inlet of the thermal diode.

[0008] Preferably, a second water pump and a third valve are provided between the water source outlet of the thermal diode and the water working medium inlet of the water source evaporator.

[0009] Preferably, the thermal diode and the heat pump working medium outlet of the air-water dual-source heat pump evaporator are connected to the heat pump working medium inlet of the air-water dual-source heat pump condenser through a second three-way valve.

[0010] Preferably, a second valve is provided on the connecting pipeline between the thermal diode and the second three-way valve; and a fifth valve is provided on the connecting pipeline between the air-water dual-source heat pump evaporator and the second three-way valve.

[0011] Preferably, a compressor is provided on the connecting pipeline between the second three-way valve and the air-water dual-source heat pump condenser.

[0012] Preferably, an electronic expansion valve is provided on the connecting pipe between the air-water dual-source heat pump condenser and the thermal diode.

[0013] Preferably, the electronic expansion valve is respectively connected to the thermal diode and the air-water dual-source heat pump evaporator through a first three-way valve; a first valve is arranged on the connecting pipeline between the first three-way valve and the thermal diode; and a fourth valve is arranged on the connecting pipeline between the first three-way valve and the air-water dual-source heat pump evaporator.

[0014] A method for operating a novel solar-coupled air-water dual-source heat pump system based on a thermal diode, based on the system, includes the following modes: Mode 1: Sunny and non-severely cold weather The water source evaporator does not work, and the heat pump working fluid is divided into two parts, one part of the heat pump working fluid is heated by solar energy; the other part of the heat pump working fluid is heated by air source; Afterwards, the two parts of the heat pump working fluid are mixed and pressurized, and heat is exchanged with the heating return water to provide heat; Mode 2: Cold and cloudy weather The thermal diode and air source evaporator do not work, and the water source is heated by solar energy. Then the low-temperature hot water source and the heat pump working fluid are heat exchanged in the water source evaporator. The heated heat pump working fluid is pressurized and then heat exchanged with the heating return water to provide heat. Mode 3: Cold and cloudy weather, and the temperature of the hot water source is lower than the preset threshold The solar PVT panels, thermal diodes and water source evaporator are all not working. The air preheater is used to preheat the air. The preheated air is used to heat the heat pump working fluid in the air source evaporator. The heated heat pump working fluid is pressurized and then heat-exchanged with the heating return water to provide heat. Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a new solar-coupled air-water dual-source heat pump system based on thermal diodes, which realizes one-way efficient transfer of heat energy by introducing and flexibly switching the working modes of air source and water source heat pumps, significantly improving the heating efficiency and adaptability of the system. The system is designed as a transfer medium for heat energy, effectively reducing heat energy loss, and realizing efficient heating, cooling and power support through multi-energy synergy, providing an innovative solution for new energy heating systems.

[0015] To sum up, the energy utilization efficiency is significantly improved: the present invention makes full use of solar energy and environmental thermal energy, realizes efficient heat transfer through thermal diodes, reduces energy loss, and realizes cascade utilization of energy; the operation mode is flexible and adjustable: the system can switch freely between air source and water source modes according to external climate conditions, adapt to heating needs under different climate conditions, and improve system operation stability and user experience; the structural design is reasonable and the operation cost is low: gravity-type thermal diodes are used to realize unidirectional heat transfer, which reduces the energy consumption of additional heat transfer devices, and reduces the noise and maintenance costs during system operation; wide applicability: the heating system of the present invention is particularly suitable for operation under complex and changeable climatic conditions, and can be widely used in heating in cold areas, industrial and agricultural hot water supply and other fields; therefore, the present invention not only effectively improves the energy efficiency level and operation stability of the heating system, but also provides an efficient and economical solution for the coupled application of solar energy and heat pump technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the system of the present invention; Among them, solar PVT panel 1, battery 2, evaporation section 3, thermal diode 4, condensation section 5, electronic expansion valve 6, air preheater 7, air-water dual-source heat pump evaporator 8, compressor 9, air-water dual-source heat pump condenser 10, first water pump 11, second water pump 12, first three-way valve 13, second three-way valve 14, first valve 15, second valve 16, third valve 17, fourth valve 18, fifth valve 19. DETAILED DESCRIPTION

[0017] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, and circuits are omitted to prevent unnecessary details from obstructing the description of the present application.

[0018] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0019] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0020] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0021] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0022] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0023] Example 1 refer to Figure 1 The present embodiment provides a novel solar-coupled air-water dual-source heat pump system based on a thermal diode, comprising a solar PVT panel 1, a battery 2, an evaporation section 3, a thermal diode 4, a condensation section 5, an electronic expansion valve 6, an air preheater 7, an air-water dual-source heat pump evaporator 8, a compressor 9, an air-water dual-source heat pump condenser 10, a first water pump 11, a second water pump 12, a first three-way valve 13, a second three-way valve 14, a first valve 15, a second valve 16, a third valve 17, a fourth valve 18 and a fifth valve 19, wherein: The power output end of the solar PVT panel 1 is connected to the input end of the battery 2, and the power output end of the battery 2 is connected to the power input end of the first water pump 11, the power input end of the second water pump 12, the power input end of the air preheater 7 and the power input end of the compressor 9 and or connected to the power grid to supply power to users.

[0024] The air preheater 7 is arranged before the air-water dual-source heat pump evaporator 8, and the air enters the air-water dual-source heat pump evaporator 8 after being preheated by the outdoor air.

[0025] The hot water outlet of the solar PVT panel 1 is connected to the inlet of the first water pump 11, and the outlet of the first water pump 11 is connected to the water source inlet of the evaporation section 3 of the gravity thermal diode 4, transferring heat to the thermal diode working medium or the hot water source of the water source evaporator, and the water source outlet of the evaporation section 3 is connected to the hot water inlet of the solar PVT panel 1, and the hot water returns to the solar PVT panel 1 to continue to heat up, thereby realizing circulation.

[0026] The thermal diode working medium outlet end of the evaporation section 3 is connected to the thermal diode working medium inlet end of the condensation section 5 of the thermal diode 4, exchanges heat with the heat pump working medium, and conducts heat to the heat pump working medium. The thermal diode working medium outlet end of the condensation section 5 is connected to the thermal diode working medium inlet end of the evaporation section 3, thereby realizing the thermal diode working medium circulation of the thermal diode 4.

[0027] The water source outlet end of the evaporation section 3 is connected to the inlet of the second water pump 12, and the outlet of the second water pump 12 is connected to the inlet of the third valve 17; the outlet of the third valve 17 is connected to the water working medium inlet of the water source evaporator in the air-water dual-source heat pump evaporator 8, and the water working medium outlet end of the water source evaporator in the air-water dual-source heat pump evaporator 8 is connected to the water source inlet of the evaporation section 3; thereby realizing the circulation of hot water.

[0028] The heat pump medium inlet of the condensing section 5 is connected to the outlet of the first valve 15, the inlet of the first valve 15 is connected to one outlet end of the first three-way valve 13, the other outlet of the first three-way valve 13 is connected to the inlet of the fourth valve 18, the outlet of the fourth valve 18 is connected to the heat pump medium inlet of the air-water dual-source heat pump evaporator 8, the heat pump medium outlet of the air-water dual-source heat pump evaporator 8 is connected to the inlet of the fifth valve 19, and the outlet of the fifth valve 19 is connected to one inlet of the second three-way valve 14. The heat pump medium output end of the condensing section 5 is connected to the inlet of the first valve 16, the outlet of the first valve 16 is connected to another inlet of the second three-way valve 14; the outlet of the second three-way valve 14 is connected to the inlet of the compressor 9, the outlet of the compressor 9 is connected to the heat pump inlet of the air-water dual-source heat pump condenser 10, the heat pump outlet of the air-water dual-source heat pump condenser 10 is connected to the inlet of the electronic expansion valve 6, and the outlet of the electronic expansion valve 6 is connected to the inlet of the first three-way valve 13.

[0029] The heat output end of the air-water dual-source heat pump condenser 10 is connected to the heat user's heating system.

[0030] In this embodiment, the heat network circulating water exchanges heat with the heat pump working fluid in the air-water dual-source heat pump condenser 10. A part of the heat pump working fluid after cooling enters the thermal diode and exchanges heat with the hot water from the solar PVT panel. The heated heat pump working fluid enters the compressor 9, and the cooled hot water returns to the solar PVT panel for heating and temperature increase; another part of the heat pump working fluid enters the air-water dual-source heat pump evaporator 8 to be heated and heated by the air source or the water source. The heated heat pump working fluid is mixed and pressurized with the heat pump working fluid output from the thermal diode in the compressor 9, and the cooled air source is discharged, or the cooled water source returns to the solar PVT panel for heating and temperature increase; the heated and pressurized heat pump working fluid enters the air-water dual-source heat pump condenser 10 to continue to exchange heat with the heat network circulating water.

[0031] This embodiment significantly improves the heating efficiency and adaptability of the system by introducing a one-way efficient transfer of heat energy and flexibly switching the working modes of air source and water source heat pumps. The system is designed as a transfer medium for heat energy, effectively reducing heat energy loss, and achieving efficient heating, cooling and power support through multi-energy synergy, providing an innovative solution for new energy heating systems.

[0032] Example 2 This embodiment is based on the system described in Embodiment 1 and provides an operation method of a novel solar-coupled air-water dual-source heat pump system based on thermal diodes. The system can operate in three modes according to external weather conditions: Mode 1: Sunny and non-cold weather (in this embodiment, the outdoor temperature is above 0°C and the solar radiation is 800W / m 2 Around, using air source to heat the heat pump working fluid) The air source evaporator in the air-water dual-source heat pump evaporator 8 is activated, the first valve 15 , the second valve 16 , the fourth valve 18 and the fifth valve 19 are opened, and the third valve 17 is closed.

[0033] Heat pump working fluid diversion and heat exchange: The heat pump working fluid is divided into two parts by the first three-way valve 13. The first part flows through the first valve 15 and enters the condensing section 5 for heat exchange and temperature rise, and high-temperature hot water is used to heat the heat pump working fluid. The second part flows through the fourth valve 18 and exchanges heat with the outdoor air in the air source evaporator for temperature rise.

[0034] Combining and boosting the heat pump working fluid: After the two parts of the heated heat pump working fluid are mixed at the second three-way valve 14, they enter the compressor 9 for boosting the pressure and increasing the temperature.

[0035] Heating and circulation: The high-temperature heat pump working fluid transfers heat to the heat user through the air-water dual-source heat pump condenser 10, and after cooling, it is depressurized by the electronic expansion valve 6 and returns to the first three-way valve 13 to complete the cycle.

[0036] Mode 2: Cold and cloudy weather (in this embodiment, the solar radiation is less than 200W / m 2 , the solar radiation duration is greater than 36 hours, the outdoor temperature is below 0℃, and the water source is used to heat the heat pump working fluid) Switch to the water source evaporator in the air-water dual-source heat pump evaporator, close the first valve 15 and the second valve 16, and open the third valve 17, the fourth valve 18 and the fifth valve 19.

[0037] Water source heat pump heat exchange: The evaporation section 3 provides low-temperature hot water, which is pressurized by the first water pump 12 and flows into the water source evaporator in the air-water dual-source heat pump evaporator 8 to exchange heat with the heat pump working fluid to increase the temperature.

[0038] Heat pump working fluid pressure boosting and heating: The heated heat pump working fluid enters the second three-way valve 14 through the fifth valve 19, is connected to the compressor 9, and after pressure boosting and temperature increase, supplies heat to heat users through the air-water dual-source heat pump condenser 10.

[0039] Cycle: After the heat pump working fluid releases heat through condensation, it is depressurized through the electronic expansion valve 6 and returns to the first three-way valve 13 to repeat the cycle.

[0040] Mode 3: Special conditions (in this embodiment, the solar radiation intensity is less than 200W / m 2 , the solar radiation duration is less than or equal to 36 hours, the outdoor temperature is below 0℃, and the air source is used to heat the heat pump working fluid) Under special conditions (such as when the water temperature in the thermal diode 4 cannot be directly heated or used as a low-temperature heat source), the air preheater 7 is activated: The air source evaporator in the air-water dual-source heat pump evaporator 8 is activated, the first valve 15 , the second valve 16 , and the third valve 17 are closed, and the fourth valve 18 and the fifth valve 19 are opened.

[0041] Heat exchange of heat pump working fluid: After passing through the first three-way valve 13, the heat pump working fluid all flows through the fourth valve 18, and exchanges heat with the preheated outdoor air in the air source evaporator of the air-water dual-source heat pump evaporator 8 to increase the temperature.

[0042] Heat pump working fluid pressure boosting and heating: The heated heat pump working fluid enters the second three-way valve 14 through the fifth valve 19, is connected to the compressor 9, and after pressure boosting and temperature increase, supplies heat to heat users through the air-water dual-source heat pump condenser 10.

[0043] Cycle: After the heat pump working fluid releases heat through condensation, it is depressurized through the electronic expansion valve 6 and returns to the first three-way valve 13 to repeat the cycle.

[0044] Utilize grid power or battery power to heat outdoor air and increase the inlet temperature of the air source evaporator, thereby improving system energy efficiency.

[0045] This embodiment makes full use of solar energy and environmental thermal energy, realizes efficient heat transfer through thermal diodes, reduces energy loss, and realizes cascade utilization of energy; it can freely switch between air source and water source modes according to external climatic conditions, adapt to heating needs under different climatic conditions, and improve system operation stability and user experience; it uses gravity-type structured thermal diodes to realize unidirectional heat transfer, reduces additional energy consumption of heat transfer devices, and reduces noise and maintenance costs during system operation; the heating system involved in this embodiment is particularly suitable for operation under complex and changeable climatic conditions, and can be widely used in heating in cold areas, industrial and agricultural hot water supply and other fields; therefore, this application not only effectively improves the energy efficiency level and operation stability of the heating system, but also provides an efficient and economical solution for the coupled application of solar energy and heat pump technology.

[0046] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A new solar-coupled air-water dual-source heat pump system based on thermal diodes, characterized in that: It includes solar PVT panels, thermal diodes, air preheaters, air-water dual-source heat pump evaporators and air-water dual-source heat pump condensers, among which: The heat pump working medium outlet of the air-water dual-source heat pump condenser is divided into two paths, one of which is connected to the heat pump working medium inlet of the thermal diode, and the other is connected to the heat pump working medium inlet of the air-water dual-source heat pump evaporator; the heat pump working medium outlet of the thermal diode and the heat pump working medium outlet of the air-water dual-source heat pump evaporator are both connected to the heat pump working medium inlet of the air-water dual-source heat pump condenser; The water supply circulating water inlet of the air-water dual-source heat pump condenser is connected to the return water pipeline of the heating network, and the water supply circulating water outlet of the air-water dual-source heat pump condenser is connected to the water supply pipeline of the heating network; The water source inlet of the thermal diode is connected to the hot water outlet of the solar PVT panel, and the water source outlet of the thermal diode is connected to the hot water inlet of the solar PVT panel; The air-water dual-source heat pump evaporator comprises an air source evaporator and a water source evaporator, wherein the inlet of the air source evaporator is connected to an air preheater; the water working medium inlet of the water source evaporator is connected to the water source outlet of the thermal diode, and the water working medium outlet of the water source evaporator is connected to the water source inlet of the thermal diode.

2. A novel solar-coupled air-water dual-source heat pump system based on thermal diode according to claim 1, characterized in that: The thermal diode comprises an evaporation section and a condensation section, wherein the evaporation section is provided with a water source inlet, a water source outlet, a thermal diode working medium inlet and a thermal diode working medium outlet, the water source inlet is respectively connected to the hot water outlet of the solar PVT panel and the water working medium outlet of the water source evaporator, and the water source outlet is respectively connected to the hot water inlet of the solar PVT panel and the water working medium inlet of the water source evaporator; The condensing section is provided with a heat pump working fluid inlet, a heat pump working fluid outlet, a thermal diode working fluid inlet and a thermal diode working fluid outlet. The heat pump working fluid inlet and outlet are respectively connected to the heat pump working fluid outlet and inlet of the air-water dual-source heat pump condenser; the thermal diode working fluid inlet and outlet are respectively connected to the thermal diode working fluid outlet and inlet on the evaporating section.

3. A novel solar-coupled air-water dual-source heat pump system based on thermal diode according to claim 1, characterized in that: A first water pump is arranged between the hot water outlet of the solar PVT panel and the water source inlet of the thermal diode.

4. A novel solar-coupled air-water dual-source heat pump system based on thermal diode according to claim 1, characterized in that: A second water pump and a third valve are provided between the water source outlet of the thermal diode and the water working medium inlet of the water source evaporator.

5. A novel solar-coupled air-water dual-source heat pump system based on thermal diode according to claim 1, characterized in that: The heat pump working medium outlet of the thermal diode and the air-water dual-source heat pump evaporator is connected to the heat pump working medium inlet of the air-water dual-source heat pump condenser through a second three-way valve.

6. A novel solar-coupled air-water dual-source heat pump system based on thermal diode according to claim 5, characterized in that: A second valve is arranged on the connecting pipeline between the thermal diode and the second three-way valve; and a fifth valve is arranged on the connecting pipeline between the air-water dual-source heat pump evaporator and the second three-way valve.

7. A novel solar-coupled air-water dual-source heat pump system based on thermal diode according to claim 5, characterized in that: A compressor is arranged on the connecting pipeline between the second three-way valve and the air-water dual-source heat pump condenser.

8. A novel solar-coupled air-water dual-source heat pump system based on thermal diode according to claim 1, characterized in that: An electronic expansion valve is arranged on the connecting pipe between the air-water dual-source heat pump condenser and the thermal diode.

9. A novel solar-coupled air-water dual-source heat pump system based on thermal diodes according to claim 8, characterized in that: The electronic expansion valve is connected to the thermal diode and the air-water dual-source heat pump evaporator respectively through the first three-way valve; a first valve is arranged on the connecting pipeline between the first three-way valve and the thermal diode; a fourth valve is arranged on the connecting pipeline between the first three-way valve and the air-water dual-source heat pump evaporator.

10. An operating method of a novel solar-coupled air-water dual-source heat pump system based on thermal diodes, characterized in that: The system according to any one of claims 1 to 9 comprises the following modes: Mode 1: Sunny and non-severely cold weather The water source evaporator does not work, and the heat pump working fluid is divided into two parts, one part of the heat pump working fluid is heated by solar energy; the other part of the heat pump working fluid is heated by air source; Afterwards, the two parts of the heat pump working fluid are mixed and pressurized, and heat is exchanged with the heating return water to provide heat; Mode 2: Cold and cloudy weather The thermal diode and air source evaporator do not work, and the water source is heated by solar energy. Then the low-temperature hot water source and the heat pump working fluid are heat exchanged in the water source evaporator. The heated heat pump working fluid is pressurized and then heat exchanged with the heating return water to provide heat. Mode 3: Cold and cloudy weather, and the temperature of the hot water source is lower than the preset threshold The solar PVT panels, thermal diodes and water source evaporator are all not working. The air is preheated by the air preheater, and the preheated air is used to heat the heat pump working fluid in the air source evaporator. The heated heat pump working fluid is pressurized and then heat-exchanged with the heating return water to provide heat.

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