A water-heat combined supply system based on solar energy and multi-heat source heat pump

Abstract

The present invention proposes a water-heat cogeneration system based on a solar-powered multi-heat-source heat pump, which integrates a concentrating photovoltaic system, a parabolic trough solar collector, a semi-effect absorption heat pump, a geothermal source heat pump, an air source heat pump, a transcritical CO2 power cycle system and an LT-MED system to simultaneously meet the user's thermal energy and fresh water needs; the photovoltaic waste heat of CPV is used to drive the semi-effect absorption heat pump, thereby fully utilizing solar energy and improving the system's heating efficiency; the heat energy generated by the PTSC system is used as a heat source to drive the TCPC system and the LT-MED system; the electrical energy generated by the CPV and the TCPC is used to drive the heat pump equipment, realizing self-production and self-sale of energy and effectively reducing system power consumption.

Description

Technical Field

[0001] The present invention belongs to the technical field of multi-energy cogeneration, and in particular relates to a water-heat cogeneration system based on a solar energy-based multi-heat source heat pump. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Solar energy has the advantages of being green, environmentally friendly, widely distributed, and having great development potential. In recent years, solar energy utilization technology has become increasingly mature. Among them, concentrating photovoltaics (CPV) is considered a very promising solar energy utilization device that can both generate electricity and recover photovoltaic waste heat, thereby achieving cogeneration of heat and power. In addition, parabolic trough solar collectors (PTSCs) are widely used as an important component of solar thermal utilization systems. However, solar energy is also subject to factors such as day and night and weather, making solar energy intermittent and unstable. Thermal storage tanks and batteries can store the excess energy generated by CPV and PTSC and release it when needed, thereby realizing energy transfer in the time dimension, effectively making up for this limitation of solar energy.

[0004] Geothermal energy is also a renewable energy source with abundant reserves, but its "renewability" is limited. Geothermal heat pumps primarily utilize shallow geothermal resources. During operation, they continuously extract heat from the soil. If excessive heat is extracted from the soil, the soil's thermal balance is disrupted, causing the heat pump's performance to decline. Air-source heat pumps offer advantages such as high efficiency, energy saving, simple structure, and environmental friendliness. Air-source heat pumps use air as a low-temperature heat source, improving energy efficiency and reducing energy costs. However, their use is subject to environmental constraints, and their heating efficiency drops significantly in severe cold weather. Coupling a geothermal heat pump with an air-source heat pump allows the air-source heat pump to replenish heat in the soil when outdoor temperatures are high, helping to maintain thermal balance. Furthermore, the stability of geothermal energy offsets the air-source heat pump's vulnerability to inclement weather, ensuring the stability of the system's heating supply.

[0005] With water shortages becoming increasingly severe, countries around the world are actively conducting research on seawater desalination. Currently, the most widely used and mature desalination technologies are reverse osmosis (RO), multiple-effect distillation (MED), and multi-stage flash (MSF). Compared to other desalination technologies, low-temperature multiple-effect distillation (LT-MED) offers advantages such as a simpler equipment structure and lower pretreatment requirements.

[0006] However, at present, there is no effective linkage control between multiple systems, and it is impossible to achieve multi-energy joint supply among multiple systems. There is a certain amount of energy waste in each system, and it is impossible to effectively achieve the comprehensive utilization of energy in each system. Summary of the Invention

[0007] To overcome the deficiencies of the above-mentioned prior art, the present invention provides a water-heat combined supply system based on a solar energy multi-heat source heat pump, which integrates a concentrating photovoltaic system, a parabolic trough solar collector, a semi-effect absorption heat pump, a geothermal source heat pump, an air source heat pump, a transcritical CO2 power cycle system and an LT-MED system to meet users' needs for thermal energy and fresh water while effectively utilizing energy.

[0008] To achieve the above objectives, the first aspect of the present invention provides a water-heat combined supply system based on a solar-powered multi-source heat pump, comprising a concentrating photovoltaic system, a parabolic trough solar collector, a semi-effect absorption heat pump, a geothermal heat pump, an air-source heat pump, a transcritical CO2 power cycle system, and an LT-MED system;

[0009] The concentrated photovoltaic system is in communication with the semi-effective absorption heat pump, so that excess heat energy generated by the concentrated photovoltaic system serves as a heat source for the semi-effective absorption heat pump;

[0010] The parabolic trough solar collector is respectively connected to the transcritical CO2 power cycle system and the LT-MED system to provide thermal energy and fresh water to users;

[0011] The electric energy generated by the concentrated photovoltaic system and the transcritical CO2 power cycle system provides electric energy for the equipment in the semi-effective absorption heat pump, the geothermal source heat pump, the air source heat pump, the transcritical CO2 power cycle system and the LT-MED system.

[0012] One or more of the above technical solutions have the following beneficial effects:

[0013] In the present invention, a concentrating photovoltaic system, a parabolic trough solar collector, a semi-effective absorption heat pump, a geothermal source heat pump, an air source heat pump, a transcritical CO2 power cycle system and an LT-MED system are integrated to simultaneously meet the user's thermal energy and fresh water needs; the photovoltaic waste heat of CPV is used to drive the semi-effective absorption heat pump, thereby fully utilizing solar energy and improving the system's heating efficiency; the heat energy generated by the PTSC system is used as a heat source to drive the TCPC system and the LT-MED system; the electrical energy generated by the CPV and the TCPC is used to drive the heat pump equipment, realizing self-production and self-sale of energy and effectively reducing system power consumption.

[0014] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0016] Figure 1 This is a flow chart of a water-heat combined supply system of a multi-heat source heat pump based on solar energy in Example 1 of the present invention. DETAILED DESCRIPTION

[0017] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0018] It should be noted that the terms used herein are for describing particular embodiments only and are not intended to limit the exemplary embodiments according to the present invention.

[0019] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0020] Example 1

[0021] This embodiment discloses a water-heat combined supply system based on a solar-powered multi-heat source heat pump, comprising: a concentrated photovoltaic system, a parabolic trough solar collector, a semi-effect absorption heat pump, a geothermal heat pump, an air-source heat pump, a transcritical CO2 power cycle system, and an LT-MED system;

[0022] The concentrated photovoltaic system is in communication with the semi-effective absorption heat pump, so that excess heat energy generated by the concentrated photovoltaic system serves as a heat source for the semi-effective absorption heat pump;

[0023] The parabolic trough solar collector is respectively connected to the transcritical CO2 power cycle system and the LT-MED system to provide thermal energy and fresh water to users;

[0024] The electric energy generated by the concentrated photovoltaic system and the transcritical CO2 power cycle system provides electric energy for the equipment in the semi-effective absorption heat pump, the geothermal source heat pump, the air source heat pump, the transcritical CO2 power cycle system and the LT-MED system.

[0025] The following combination Figure 1The system proposed in this embodiment is described in detail, specifically including a CPV system, a PTSC system, a semi-effect absorption heat pump, a geothermal heat pump, an air-source heat pump, a transcritical CO2 power cycle (TCPC) system, a LT-MED system, a thermal storage tank, and a battery. Part of the thermal energy generated by the CPV system serves as a heat source to drive the semi-effect absorption heat pump, while the remaining portion is used to supply heat to end-users. The thermal energy generated by the PTSC system serves as a heat source to drive the TCPC system and the LT-MED system, providing heat and fresh water to users. The electrical energy generated by the CPV and TCPC systems is used to drive the heat pump equipment, coupling the geothermal heat pump with the air-source heat pump. The air-source heat pump can replenish heat to the soil when outdoor temperatures are high, helping to maintain thermal balance. Furthermore, the stability of geothermal energy compensates for the air-source heat pump's vulnerability to inclement weather, ensuring the stability of the system's heating supply. Because both solar and air-source heat pumps are subject to environmental constraints, the start and stop of each subsystem is controlled according to different environmental conditions, providing different system operation strategies to meet user needs for heat and fresh water.

[0026] In this embodiment, in the CPV subsystem, sunlight shines on the surface of the photovoltaic cell, but only a small part of the solar energy can be converted into electrical energy, and the rest is discharged into the atmosphere in the form of heat energy to prevent the temperature of the photovoltaic cell from being too high and affecting its photoelectric conversion efficiency. Since the temperature of this part of the discharged waste heat is not high (60-70°C), it is generally discharged directly into the atmosphere and cannot be effectively utilized. The operating temperature range of the semi-effective absorption heat pump is 50-70°C, and the temperature of the waste heat just matches it. Therefore, it can be used as a heat source to drive the semi-effective absorption heat pump system. A fluid channel is installed on the back of the concentrating photovoltaic, and the heat transfer oil in pipeline 1 is sent into the fluid channel through the first pump PI to absorb the photovoltaic waste heat, thereby controlling the operating temperature of the photovoltaic cell. After absorbing the waste heat from photovoltaics, the thermal oil is transported via second pipe 2 to the thermal storage tank (Hot Tank I) for storage. The electricity generated by the photovoltaic cells is then transferred to the storage battery (Storage Battery) for storage. This power is used to power the second and third pumps PII and PIII in the semi-absorption heat pump, the first compressor ComI in the geothermal heat pump, the second compressor ComII in the air-source heat pump, the fifth pump PV in the TCPC system, and the sixth pump PVI in the LT-MED system. Because this waste heat is fully recycled, the photovoltaic cells can operate at an optimal temperature, improving the overall efficiency of the system.

[0027] The semi-effective absorption heat pump system consists of two solution loops, which circulate in two different pressure stages, low pressure and high pressure. In the low-pressure stage, the intermediate medium (water) that exchanges heat with the heat transfer oil in the pipe 3 flowing out of the first heat storage tank Hot TankⅠ flows into the low-pressure generator GENⅠ as a driving heat source. The ammonia solution is heated and evaporated in the low-pressure generator GENⅠ. The concentrated ammonia vapor evaporated enters the high-pressure absorber HP-ABS through the pipe 11, and the weak ammonia solution enters the low-pressure solution heat exchanger HEXⅡ through the pipe 5. In the second low-pressure solution heat exchanger HEXⅡ, the weak ammonia solution exchanges heat with the ammonia solution pressurized by the second pump PⅡ, and the temperature is reduced; then it enters the first low-pressure solution heat exchanger HEXⅡ through the pipe 6. A low-pressure solution throttle valve ValⅠ, after throttling and reducing the pressure through the first low-pressure solution throttle valve ValⅠ, enters the low-pressure absorber LP-ABS through pipeline 7, and then the ammonia solution enters the second pump PⅡ through pipeline 8 for pressurization. The ammonia solution pressurized by the second pump PⅡ enters the second low-pressure solution heat exchanger HEXⅡ through pipeline 9; in the second low-pressure solution heat exchanger HEXⅡ, the weak ammonia solution exchanges heat with the ammonia solution pressurized by the second pump PⅡ, the temperature is reduced, and then it is sent back to the low-pressure generator GENⅠ through pipeline 10.

[0028] The low-pressure absorber LP-ABS is connected to the user's return water pipeline. After passing through the first low-pressure solution throttle valve Val I and pipeline 7, the weak ammonia solution is absorbed in the low-pressure absorber LP-ABS, releasing a large amount of heat of solution. The user's return water pipeline absorbs this heat released by the low-pressure absorber to provide heating for the user.

[0029] The low-pressure absorber LP-ABS is also connected to the first evaporator Eva I. The concentrated ammonia vapor evaporated from the first evaporator Eva I enters the low-pressure absorber LP-ABS via pipeline 21. The weak ammonia solution is throttled and reduced in pressure by the first low-pressure solution throttle valve Val I before being absorbed within the low-pressure absorber LP-ABS, releasing a significant amount of heat of solution. The ammonia solution then passes through pipeline 8, is pressurized by the second pump P II, and undergoes heat exchange in the second heat exchanger HEX II, raising its temperature. The solution is then returned to the low-pressure generator GEN I via pipeline 10.

[0030] The solution circuit in the high-pressure stage is similar to that in the low-pressure stage. The intermediate medium (water) that exchanges heat with the thermal oil in pipe 3 flowing out of the first thermal storage tank Hot Tank I flows into the high-pressure generator GEN II as the driving heat source. The ammonia solution is heated and evaporated in GEN II. The concentrated ammonia vapor that evaporates enters the first condenser Cond I through pipe 18 for condensation. After throttling and reducing the pressure through the third throttle valve Val III, it enters the first evaporator Eva I.

[0031] The weak ammonia solution in GENⅡ in the high-pressure generator enters the high-pressure solution heat exchanger HEXⅢ through pipeline 12, exchanges heat with the ammonia solution pressurized by the third pump PⅢ in the high-pressure solution heat exchanger HEXⅢ, and the temperature is reduced. Then, after throttling and reducing the pressure through the second high-pressure solution throttle valve ValⅡ, it enters the high-pressure absorber HP-ABS.

[0032] The concentrated ammonia vapor evaporated from the low-pressure generator GEN I enters the high-pressure absorber HP-ABS via pipeline 11. The weak ammonia solution in the high-pressure generator GEN II passes through the high-pressure solution heat exchanger HEX III, pipeline 13, the second high-pressure solution throttle valve Val II, and pipeline 14 to enter the high-pressure absorber HP-ABS, where it is absorbed, releasing a large amount of heat of solution. The ammonia solution in the high-pressure absorber HP-ABS enters the third pump P III via pipeline 15. After being pressurized by the third pump P III, it enters the high-pressure solution heat exchanger HEX III via pipeline 16. Heat exchange occurs in HEX III, raising its temperature, and then it is returned to the high-pressure generator GEN II.

[0033] In this embodiment, the low-pressure absorber LP-ABS, the high-pressure absorber HP-ABS, and the condenser in the semi-effect absorption heat pump subsystem are all connected to the user's return water pipeline.

[0034] This embodiment utilizes two cycles, low-pressure and high-pressure. This structure increases the cycle's pressure-raising capacity, allowing the utilization of lower-temperature heat sources. Because the waste heat from CPV is relatively low (60-70°C), a semi-effective absorption heat pump is employed, splitting the cycle into two cycles: low-pressure and high-pressure.

[0035] In this embodiment, in a geothermal heat pump, the heat transfer medium evaporates in the second evaporator Eva II, absorbing heat from the circulating water that exchanges heat with the soil. The heat transfer medium exiting the second evaporator Eva II enters the first compressor Com I via pipeline 22. After compression by the first compressor Com I, it becomes high-temperature, high-pressure gas. It then enters the second condenser Cond II via pipeline 23, where it condenses and releases heat, providing heating for the user. The liquid medium in the second condenser Cond II flows through pipeline 24 into the fourth throttle valve Val IV. After throttling and reducing the pressure by the fourth throttle valve Val IV, it enters the second evaporator Eva II for further evaporation, completing the cycle.

[0036] In this embodiment, in an air-source heat pump, the heat transfer medium evaporates in the third evaporator Eva III, absorbing heat from the air. The heat transfer medium exiting the third evaporator Eva III enters the second compressor Com II via pipeline 26. After compression by the second compressor Com II, it becomes a high-temperature, high-pressure gas. It then enters the third condenser Cond III via pipeline 27 for condensation and releases heat, providing heating for the user. The liquid medium exiting the third condenser Cond III flows through pipeline 28 into the fifth throttle valve Val V. After throttling and reducing the pressure there, it enters the third evaporator Eva III for further evaporation, completing the cycle. When the outdoor temperature is high, the air-source heat pump can replenish heat to the soil, helping to maintain thermal balance.

[0037] In the parabolic trough solar thermal collector (PTSC) system of this embodiment, sunlight strikes the surface of a parabolic reflector, which then concentrates the received sunlight onto the surface of a heat collecting tube. The second waste heat generator (HRSG II) is connected to pipeline 30. The thermal oil in pipeline 30 is pumped by a fourth pump (P IV) to the parabolic trough solar thermal collector (PTSC), where it absorbs heat. The thermal oil then flows out of the PTSC and is transported via pipeline 32 to the second thermal storage tank (Hot Tank II) for storage.

[0038] The thermal oil in the second heat storage tank, Hot Tank II, releases heat sequentially through two waste heat boilers: the first waste heat boiler (HRSG I) and the second waste heat boiler (HRSG II). The generated heat energy serves as a heat source to drive the TCPC and LT-MED systems, providing heat and fresh water to users. When sunlight is abundant, the generated heat energy is sufficient to meet user loads, and the excess is stored. When sunlight is insufficient, the generated heat energy is insufficient to meet user loads, and the stored heat energy is released. Through energy storage, this system can meet user loads under varying sunlight conditions.

[0039] In the transcritical CO2 power cycle (TCPC) system of this embodiment, CO2 absorbs heat in the first waste heat boiler (HRSG) I, then enters the first turbine (Turb I) to expand and generate work, driving the generator. The electricity generated by the TCPC system, along with the electricity generated by the CPV, is transferred to the storage battery for storage. This energy is used to power the second and third pumps (PII and PIII) in the semi-effect absorption heat pump, the first compressor (ComI) in the geothermal heat pump, the second compressor (ComII) in the air-source heat pump, the fifth pump (PV) in the TCPC system, and the sixth pump (PVI) in the LT-MED system. The CO2 then enters the fourth regenerator (HEXIV) via pipeline 36, where it exchanges heat with the CO2 flowing from the fifth pump (PV), reducing its temperature. The CO2 then enters the residential water heat exchanger (RWHE) via pipeline 37, where it exchanges heat with the return water from the user terminal, providing domestic hot water for the user.

[0040] The carbon dioxide flowing out of the residential water heat exchanger (RWHE) enters the fourth condenser (Cond IV) via pipeline 38, where it condenses and releases heat. It then flows through pipeline 39 to the fifth pump (PV). After being pressurized by the fifth pump (PV), it enters the regenerator (HEX IV) via pipeline 40. Within HEX IV, the carbon dioxide flowing out of the fifth pump (PV) heats up, recovering some of its heat. It then flows through pipeline 41 to the first waste heat boiler (HRSG I) for the next cycle.

[0041] In the low-temperature multiple-effect distillation system, the condensed water discharged from the LT-MED enters the sixth pump PVI through pipeline 43. After being pressurized by the sixth pump PVI, it enters the second waste heat boiler HRSGⅡ. In the second waste heat boiler HRSGⅡ, it absorbs the heat carried by the heat transfer oil flowing out of the first waste heat boiler HRSGⅠ and evaporates, serving as the driving steam for the LT-MED.

[0042] The driving steam is fed via pipeline 42 into the first-effect evaporator of the LT-MED, releasing its latent heat of vaporization to heat the first-effect feed seawater. The feed seawater, entering through the overhead spray system, absorbs the heat and evaporates, and the steam enters the tubes of the next effect, continuing to serve as a heat source. In the final effect, the evaporated seawater steam enters the MED condenser and condenses into fresh water. The condensed water from the driving steam returns to the waste heat boiler (HRSG II) for evaporation.

[0043] The operating conditions of the water-heat combined supply system based on solar energy multi-heat source heat pumps provided in this embodiment are described as follows:

[0044] When there is sufficient sunlight outside and the heat energy generated by the CPV system, TCPC system and semi-effect absorption heat pump meets user needs, the geothermal heat pump and air source heat pump will not work; the LT-MED system will provide fresh water for users; and excess energy will be stored in the heat storage tank and battery.

[0045] When external sunlight weakens or user demand increases, the air source heat pump starts. At this time, the air source heat pump extracts heat from the air, transfers the heat energy to the user through a thermodynamic cycle, releases the heat in the heat storage tank (Hot Tank II) to drive the normal operation of the LT-MED system, and provides fresh water to users. The heat in the heat storage tank (Hot Tank I) is released as needed.

[0046] When the weather is bad, the CPV system and PTSC system are difficult to operate normally, and the thermal efficiency of the air source heat pump is low. At this time, the geothermal heat pump is activated, and the air source heat pump assists in heating; the heat in the heat storage tank (Hot Tank II) is released to drive the normal operation of the LT-MED system to provide fresh water for users, and the heat in the heat storage tank (Hot Tank I) is released to drive the normal operation of the semi-effect absorption heat pump to provide the thermal energy required by users.

[0047] Advantages of this embodiment:

[0048] (1) It integrates the CPV system, PTSC system, semi-effect absorption heat pump, geothermal source heat pump, air source heat pump, transcritical CO2 power cycle (TCPC) system, LT-MED system, heat storage tank and battery, and meets the user's heat energy and fresh water needs at the same time. The photovoltaic waste heat of CPV is used to drive the semi-effect absorption heat pump, which fully utilizes solar energy and improves the heating efficiency of the system. In addition, the system uses solar energy, geothermal source heat pump and air source heat pump at the same time, effectively responding to the "carbon peak and carbon neutrality" policy, and has reference significance for the effective use of renewable energy.

[0049] (2) The photovoltaic waste heat of CPV is used to drive a semi-effective absorption heat pump, and the heat energy generated by the PTSC system is used as a heat source to drive the TCPC system and the LT-MED system; the electricity generated by CPV and TCPC is used to drive the heat pump equipment, realizing self-production and self-sale of energy and effectively reducing system power consumption.

[0050] (3) The thermal storage tank and battery can store the excess energy generated by CPV and PTSC and release it when needed, thereby realizing the transfer of energy in the time dimension and effectively making up for the limitation of solar energy.

[0051] (4) According to different environmental conditions, control the start and stop of each subsystem and provide different system operation strategies to meet the user's demand for heat energy and fresh water.

[0052] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A water and heat combined supply system based on solar energy multi-heat source heat pump, characterized in that: Including concentrated photovoltaic systems, parabolic trough solar collectors, semi-effect absorption heat pumps, geothermal heat pumps, air source heat pumps, transcritical CO2 power cycle systems and LT-MED systems; The concentrated photovoltaic system is in communication with the semi-effective absorption heat pump, so that excess heat energy generated by the concentrated photovoltaic system serves as a heat source for the semi-effective absorption heat pump; The parabolic trough solar collector is respectively connected to the transcritical CO2 power cycle system and the LT-MED system to provide thermal energy and fresh water to users; The electric energy generated by the concentrated photovoltaic system and the transcritical CO2 power cycle system provides electric energy for the equipment in the semi-effective absorption heat pump, the geothermal source heat pump, the air source heat pump, the transcritical CO2 power cycle system and the LT-MED system.

2. The water-heat combined supply system of a solar-based multi-heat source heat pump according to claim 1, characterized in that: The concentrated photovoltaic system includes a concentrated photovoltaic and a fluid channel arranged on the concentrated photovoltaic. After the fluid enters the fluid channel through a first pump to absorb photovoltaic waste heat, it is transported to a first heat storage tank for storage.

3. The water-heat combined supply system of a solar-based multi-heat source heat pump according to claim 2, characterized in that: The semi-effective absorption heat pump system includes a low-pressure solution circuit, which includes a second heat exchanger, a low-pressure solution throttle valve, a low-pressure absorber, and a second pump in a circular connection; a low-pressure generator exchanges heat with a first heat storage tank; and in the second heat exchanger, the solution flowing out of the low-pressure generator exchanges heat with the solution pressurized by the second pump.

4. The water-heat combined supply system of a solar-based multi-heat source heat pump according to claim 3, characterized in that: The semi-effective absorption heat pump system also includes a high-pressure solution circuit, which includes a third heat exchanger, a high-pressure solution throttle valve, a high-pressure absorber and a third pump in a cyclic communication. The high-pressure absorber is connected to the low-pressure generator, and the high-pressure generator exchanges heat with the first heat storage tank. In the third heat exchanger, the solution flowing out of the high-pressure generator exchanges heat with the solution pressurized by the third pump.

5. The water-heat combined supply system of a multi-heat source heat pump based on solar energy according to claim 4, characterized in that: The high-pressure generator is also connected to the first condenser, the third throttle valve and the first evaporator in sequence.

6. The water-heat combined supply system of a solar-based multi-heat source heat pump according to claim 1, characterized in that: In the geothermal source heat pump, the heat transfer medium absorbs heat from the circulating water that exchanges heat with the soil, and then passes through the second evaporator, the first compressor, and the second condenser in sequence to provide heating for users; the liquid medium passing through the second condenser is throttled and reduced in pressure by the fourth throttle valve and then enters the second evaporator.

7. The water-heat combined supply system of a solar-based multi-heat source heat pump according to claim 1, characterized in that: In the air source heat pump, after the heat transfer medium absorbs heat from the air, it passes through the third evaporator, the second compressor and the third condenser in sequence to provide heating for the user; the liquid medium passing through the third condenser is throttled and reduced in pressure by the fifth throttle valve and then enters the third evaporator.

8. The water-heat combined supply system of a solar-based multi-heat source heat pump according to claim 1, characterized in that: The parabolic trough solar thermal collector system includes a fifth pump, a solar thermal collector, a second heat storage tank, a first waste heat boiler, and a second waste heat boiler that are cyclically connected.

9. The water-heat combined supply system of a solar-based multi-heat source heat pump according to claim 8, characterized in that: In the transcritical CO2 power cycle system, after absorbing heat in the first waste heat boiler, the carbon dioxide enters the first turbine to perform work and drive the generator to generate electricity; the carbon dioxide passing through the first turbine passes through the fourth regenerator, the residential water heat exchanger, the fourth condenser and the fifth pump in sequence and returns to the fourth regenerator for heat exchange. The carbon dioxide after heat exchange in the fourth regenerator enters the first waste heat boiler.

10. The water-heat combined supply system of a solar-based multi-heat source heat pump according to claim 8, characterized in that: The LT-MED system includes a LT-MED, a sixth pump, and the second waste heat boiler in circular communication.

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