Heat-dominated island integrated energy system based on multi-energy complementation and operation method of heat-dominated island integrated energy system

Abstract

The invention discloses a heat-dominated island integrated energy system based on multi-energy complementation and an operation method of the heat-dominated island integrated energy system, and belongs to the technical field of integrated energy utilization. The system supplies power to an island power grid through a wind driven generator and photovoltaic heat, produces hydrogen through an electrolytic tank, stores hydrogen through a hydrogen storage tank, and supplies the hydrogen to a hydrogen load or generates power through a fuel cell. According to the system, a low-pressure and low-temperature heat storage tank and a high-pressure heat storage tank group (high-pressure medium-temperature / high-pressure low-temperature) are innovatively constructed, and photovoltaic heat, waste heat of a hydrogen electrolytic tank and waste heat of a fuel cell are recycled and stored in the low-pressure and low-temperature heat storage tank. The low-temperature heat energy is used as a heat source of a heat pump after being subjected to auxiliary heating of a geothermal well, and heat generated by the heat pump is stored in a high-pressure medium-temperature heat storage tank The heat energy of the high-pressure medium-temperature heat storage tank can be supplied to the medium-temperature heat load and can also drive the ORC system to generate power. Efficient gradient utilization of wind, light, terrestrial heat and waste heat is achieved, and the energy self-sufficiency rate and the system stability of the island microgrid are remarkably improved through bidirectional flexible adjustment of electric power and thermal power.

Description

Technical Field

[0001] This invention relates to the fields of integrated energy utilization, microgrids and thermal energy engineering technology, specifically to a multi-energy complementary, heat-dominant integrated energy system for isolated islands and its operation method, suitable for high-altitude, cold, and remote island regions. Background Technology

[0002] In remote and isolated areas such as the Qinghai-Tibet Plateau, polar research stations, and remote islands and reefs, building independent renewable energy supply systems is crucial for ensuring survival and development. These scenarios have unique "high-altitude and cold island" characteristics: extremely low ambient temperatures, drastic fluctuations in wind and solar resources, and a significant "high heat priority" characteristic in end-user loads (heating and other heat loads account for a very large proportion).

[0003] Existing isolated microgrid technologies primarily follow an "electricity-dominated" paradigm, centered on photovoltaic / wind power and lithium batteries. However, in extremely cold environments, electrochemical energy storage faces challenges such as severe capacity degradation, limited charging and discharging power, and shortened lifespan. Furthermore, to cope with consecutive periods of calm or no sunlight, electricity-dominated systems require massive battery capacity, resulting in extremely high costs. Moreover, when batteries are depleted, the system faces the risk of "power outage and thermal shutdown," failing to guarantee survival-level heating.

[0004] While hydrogen energy storage (electricity-hydrogen-electricity) solves the problem of long-term energy storage, its overall cycle efficiency is low, and the management of high-pressure hydrogen in harsh environments poses safety risks. More importantly, existing systems often overlook the potential of "thermal energy" as an energy buffer, failing to fully utilize the role of low-temperature characteristics in high-altitude environments in improving the efficiency of thermodynamic cycles (such as ORC).

[0005] Therefore, there is an urgent need for a new energy system architecture that breaks away from the "electricity-dominated" model and establishes a core of thermal energy storage and circulation, enabling multi-energy complementarity, thermo-electric decoupling, and cascade utilization. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-energy complementary, heat-dominated, isolated integrated energy system and its operation method. By constructing a hierarchical thermal storage architecture and a two-way thermoelectric conversion path, it achieves efficient coupling and spatiotemporal decoupling of wind, solar, hydrogen, geothermal and waste heat, thereby improving the system's resilience and energy utilization in high-altitude, cold, isolated environments.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A multi-energy complementary, heat-dominated islanded integrated energy system includes a power supply unit, a hydrogen energy subsystem, a waste heat recovery and low-temperature thermal storage subsystem, a heat pump coupled geothermal subsystem, a high-pressure thermal storage and medium-temperature heating subsystem, and an organic Rankine cycle (ORC) power generation system.

[0008] The power supply unit includes a wind turbine and a photovoltaic thermal module, which are respectively connected to an islanded power grid, and the islanded power grid is connected to an electrical load.

[0009] The hydrogen energy subsystem includes a hydrogen electrolyzer, a hydrogen storage tank, a hydrogen load, and a hydrogen fuel cell. The hydrogen electrolyzer is powered by an islanded power grid, and its hydrogen outlet is connected to the hydrogen storage tank via valve eight. The hydrogen storage tank is connected to the hydrogen load via valve ten and to the hydrogen fuel cell via valve seven. The hydrogen fuel cell generates electricity and is connected to the islanded power grid or an independent load.

[0010] The waste heat recovery and cryogenic thermal storage subsystem includes a low-pressure cryogenic thermal storage tank. The photovoltaic thermal module, hydrogen electrolyzer, and hydrogen fuel cell are all equipped with waste heat output pipelines. Each waste heat output terminal is connected to the inlet of the low-pressure cryogenic thermal storage tank through a pipeline, and waste heat hot water is transported to the low-pressure cryogenic thermal storage tank for storage through the cooperation of pumps and valves.

[0011] The heat pump coupled geothermal subsystem includes a heat pump unit and a geothermal well. One outlet of the low-pressure low-temperature heat storage tank is heated by the geothermal well and then connected to the evaporator side of the heat pump unit. The low-temperature hot water in the low-pressure low-temperature heat storage tank is heated by the geothermal well and then used as the heat source for the heat pump evaporator. The heat pump unit boosts the low-grade heat energy and then delivers it to the high-pressure heat storage subsystem.

[0012] The high-pressure thermal storage and medium-temperature heating subsystem includes a high-pressure medium-temperature thermal storage tank and a high-pressure low-temperature thermal storage tank. The condenser side of the heat pump unit is connected between the high-pressure low-temperature thermal storage tank and the high-pressure medium-temperature thermal storage tank. The high-pressure medium-temperature thermal storage tank is connected to a composite parabolic concentrator (CPC) collector, which uses ambient cold water for heating to supplement heat. The high-pressure medium-temperature thermal storage tank supplies heat to the medium-temperature heat load through a medium-temperature heat load heat exchanger. The heat energy is used to drive the medium-temperature heat load heat exchanger and the ORC power generation system. The return water flows into the high-pressure low-temperature thermal storage tank, and is then heated by the heat pump and circulated back to the high-pressure medium-temperature thermal storage tank.

[0013] The ORC power generation system includes an ORC evaporator, an expander, an ORC generator, and an ORC condenser (4); the outlet of the high-pressure medium-temperature heat storage tank is connected to the primary side inlet of the ORC evaporator. The ORC power generation system uses the thermal energy of the high-pressure medium-temperature heat storage tank to drive the expander to do work and generate electricity. The generated electricity is supplied to the island power grid or electrical load. The condensation process uses ambient cold water for cooling.

[0014] The present invention also provides an operation method for the aforementioned multi-energy complementary heat-dominated islanded integrated energy system, comprising the following steps: when the system has surplus power, the compressor of the heat pump system is driven first to generate heat and store the heat in a high-pressure medium-temperature thermal storage tank; if there is still surplus power, the hydrogen electrolysis cell is started to produce hydrogen and store it; when the system has insufficient power, the hydrogen fuel cell is started first to generate electricity; if the power is still insufficient, the heat from the high-pressure medium-temperature thermal storage tank is used to start the ORC power generation system for supplementary power generation.

[0015] The present invention has the following beneficial effects: Thermal-dominated architecture: It establishes an energy buffer pool with low-pressure low-temperature thermal storage tanks and high-pressure thermal storage tank groups as the core, and uses the high thermal inertia of thermal energy to suppress source fluctuations, thus solving the problem of battery performance degradation in extremely cold environments.

[0016] Full-chain cascade utilization: All low-grade waste heat from photovoltaic, hydrogen production, and power generation processes is recovered to a cryogenic tank, then boosted by geothermal energy and converted into medium- and high-temperature heat energy by a heat pump, and finally utilized through ORC or heating, achieving a "fully utilized" cascade utilization.

[0017] Survival-level safety guarantee: In extreme power shortage conditions, the system can independently maintain heating by relying on stored thermal energy, and support critical loads through ORC reverse power generation, thus avoiding systemic paralysis.

[0018] Complementary and synergistic effects: Using cold water from the high-altitude environment as the ORC cold source significantly improves the heat-to-electricity conversion efficiency; using geothermal energy to increase the heat pump evaporation temperature improves the heat pump COP and achieves environmental adaptability optimization. Attached Figure Description

[0019] Figure 1 This invention provides an overall structural schematic diagram of a multi-energy complementary, heat-dominated, islanded integrated energy system.

[0020] The component numbers in the diagram are explained as follows: 1-Wind turbine generator; 2-Electric load; 3-Pump 1; 4-ORC condenser; 5-Pump 2; 6-Regenerator; 7-Expander; 8-ORC generator; 9-Pump 3; 10-Medium-temperature heat exchanger 2; 11-Valve 1; 12-Medium-temperature heat exchanger 1; 13-Pump 4; 14-Valve 2; 15-High-pressure medium-temperature heat storage tank; 16-ORC evaporator; 17-High-pressure low-temperature heat storage tank; 18-Valve 3; 19-Valve 4; 20-Heat pump evaporator; 21-Heat pump expansion valve; 22-Heat pump condenser; 23-Heat pump compressor; 24-CPC collector; 25- 26-Pump 5; 27-Pump 6; 28-Geothermal Well; 29-Pump 7; 30-Hydrogen Fuel Cell; 31-Hydrogen Electrolyzer; 32-Valve 6; 33-Valve 7; 34-Valve 8; 35-Valve 9; 36-Valve 10; 37-Pump 8; 38-Pump 9; 39-Valve 11; 40-Photovoltaic Thermal Module; 41-Pump 10; 42-Low-Pressure Low-Temperature Thermal Storage Tank; 43-Low-Temperature Heat Load Heat Exchanger; 44-Pump 11; 45-Low-Temperature Heat Load; 46-Valve 12; 47-Pump 12; 48-Valve 13; 49-Valve 14; 50-Hydrogen Storage Tank; 51-Hydrogen Load; 52-Medium-Temperature Heat Load; 53-Islanded Power Grid. Detailed Implementation

[0021] The following is in conjunction with the appendix Figure 1 The specific embodiments of the present invention will be described in detail below.

[0022] like Figure 1 As shown, the present invention provides a multi-energy complementary, heat-dominated island integrated energy system, which mainly consists of a power supply unit, a hydrogen energy subsystem, a waste heat recovery and low-temperature thermal storage subsystem, a heat pump coupled geothermal subsystem, a high-pressure thermal storage and medium-temperature heating subsystem, and an ORC power generation system.

[0023] The power supply unit of this invention uses wind and solar power generation, including a wind turbine generator 1 and a photovoltaic thermal module 40, both of which are connected to an islanded power grid 53 to supply power.

[0024] The hydrogen energy subsystem of this invention provides hydrogen electrolysis and hydrogen fuel cell power supply, mainly including a hydrogen electrolyzer 31, a hydrogen storage tank 50, and a hydrogen fuel cell 30; wherein the hydrogen electrolyzer 31 is powered by an islanded power grid 53, and its hydrogen outlet is connected to the hydrogen storage tank 50 via valve 8 34; the hydrogen storage tank 50 is connected to a hydrogen load 51 via valve 10 36 and to the hydrogen fuel cell 30 via valve 7 33.

[0025] This invention relates to a waste heat recovery and cryogenic thermal storage subsystem for the recovery and utilization of waste heat from power generation and electrolysis. It mainly includes a low-pressure cryogenic thermal storage tank 42. The waste heat hot water outlet of the hydrogen electrolyzer 31 is connected to the low-pressure cryogenic thermal storage tank 42 sequentially via valve nine 35 and pump nine 38; the waste heat hot water outlet of the hydrogen fuel cell 30 is connected to the low-pressure cryogenic thermal storage tank 42 sequentially via valve six 32 and pump eight 37; and the hot water outlet of the photovoltaic thermal module 40 is connected to the low-pressure cryogenic thermal storage tank 42 sequentially via valve eleven 39 and pump ten 41. Through this structure, the waste heat from the hydrogen electrolyzer 31, hydrogen fuel cell 30, and photovoltaic thermal module 40 is collected and utilized.

[0026] This invention relates to a heat pump coupled geothermal subsystem for geothermal energy coupling applications, primarily comprising a heat pump unit and a geothermal well 28. Due to the low level of collected waste heat, direct utilization is difficult. Therefore, this invention introduces a heat pump unit and geothermal well 28, mainly by connecting one outlet of the low-pressure, low-temperature heat storage tank 42, heated by the geothermal well 28, to the evaporator side of the heat pump unit. Further, the low-pressure, low-temperature heat storage tank 42 of this invention has three outputs: the first output connects to the primary inlet of the low-temperature heat load heat exchanger 43 via valve 13 48, and is discharged via pump 12 47 after heat exchange; the second output, a crucial component, is heated by the geothermal well 28, enters the primary inlet of the heat pump evaporator 20 via pump 6 27, and returns to the low-pressure, low-temperature heat storage tank 42 via valve 14 49 after heat exchange; the third output sequentially enters the primary inlet of the medium-temperature heat exchanger 12 via pump 7 29 and valve 5 25, and is discharged after heat exchange. Based on this structure, this invention provides three further forms of utilization for the collected waste heat. In this invention, the low-temperature heat load 45 is connected to the secondary side loop of the low-temperature heat load heat exchanger 43. Its heating circuit is as follows: the secondary side outlet of the low-temperature heat load heat exchanger 43 is connected to pump 11 44, and after passing through the low-temperature heat load 45 and valve 12 46, it returns to the secondary side inlet of the low-temperature heat load heat exchanger 43. The circulation loop of the heat pump unit includes: the secondary side outlet of the heat pump evaporator 20 is connected to the inlet of the compressor 23; the outlet of the compressor 23 is connected to the primary side inlet of the heat pump condenser 22; and its outlet is connected to the secondary side inlet of the heat pump evaporator 20 via the heat pump expansion valve 21.

[0027] This invention relates to a high-pressure thermal storage and medium-temperature heating subsystem for storing and releasing heat. It mainly includes a high-pressure medium-temperature thermal storage tank 15 and a high-pressure low-temperature thermal storage tank 17. The condenser side of a heat pump unit is connected between the high-pressure low-temperature thermal storage tank 17 and the high-pressure medium-temperature thermal storage tank 15. The high-pressure medium-temperature thermal storage tank 15 is connected to a CPC collector 24. The high-pressure medium-temperature thermal storage tank 15 supplies heat to a medium-temperature heat load 52 through a medium-temperature heat exchanger 20. Specifically, the high-pressure thermal storage connection is as follows: the outlet of the high-pressure low-temperature thermal storage tank 17 is connected to the secondary inlet of the heat pump condenser 22 via valve 4 19 and pump 5 26, and the secondary outlet of the heat pump condenser 22 is connected to the high-pressure medium-temperature thermal storage tank 15. The heat output path of the high-pressure medium-temperature heat storage tank 15 includes: one path connecting to the primary side inlet of the ORC evaporator 16, and the primary side outlet of the ORC evaporator 16 connecting to the high-pressure low-temperature heat storage tank 17 via valve three 18; the other path connecting to the primary side inlet of the medium-temperature heat load heat exchanger two 10, and the primary side outlet of the medium-temperature heat load heat exchanger two 10 connecting to the high-pressure low-temperature heat storage tank 17; the CPC collector 24 is heated by ambient cold water and connected to the high-pressure medium-temperature heat storage tank 15 via valve two 14 and pump four 13. The heating circuit of the medium-temperature heat load 52 is as follows: the secondary side outlet of the medium-temperature heat load heat exchanger two 10 passes sequentially through pump three 9, medium-temperature heat load 52 and valve one 11, enters the secondary side inlet of the medium-temperature heat load heat exchanger one 12, and the secondary side outlet of the medium-temperature heat load heat exchanger one 12 returns to the secondary side inlet of the medium-temperature heat load heat exchanger two 10.

[0028] The ORC power generation system of this invention recovers low- and medium-temperature thermal energy and generates electricity. It mainly includes an ORC evaporator 16, an expander 7, an ORC generator 8, and an ORC condenser 4. The circulation loop of the ORC power generation system is as follows: the secondary side outlet of the ORC evaporator 16 is connected to the expander 7, and the expander 7 is connected to the ORC generator 8. The outlet of the expander 7 passes sequentially through the primary side of the regenerator 6, the primary side of the ORC condenser 4, and pump 5, and then returns to the secondary side inlet of the ORC evaporator 16 through the secondary side of the regenerator 6. The secondary side of the ORC condenser 4 is cooled by ambient cold water and discharged through pump 3.

[0029] In terms of functionality, the above components can be combined as follows: power supply and hydrogen production and storage module, waste heat recovery and low temperature thermal storage module, heat pump boosting module, high-pressure thermal storage and medium-temperature utilization module, and ORC power generation module.

[0030] 1. Power Supply and Hydrogen Production & Storage Module: The primary energy source of this invention comes from a wind turbine 1 and a photovoltaic thermal module 40. The electricity generated by both is fed into the isolated power grid 53, prioritizing the supply to user loads 2. When there is a power surplus, the isolated power grid 53 drives the hydrogen electrolyzer 31 to electrolyze water to produce hydrogen. The produced hydrogen is stored in the hydrogen storage tank 50 via valve 8 34. The hydrogen in the storage tank 50 has two pathways: one is to supply hydrogen loads 51 (such as hydrogen fuel cell vehicles or industrial hydrogen) via valve 10 36; the other is to enter the hydrogen fuel cell 30 through valve 7 33 to generate electricity and supplement the power supply of the isolated power grid when the system is short of power.

[0031] 2. Waste Heat Recovery and Low-Temperature Thermal Storage Module: This module is equipped with a low-pressure low-temperature thermal storage tank 42, used to collect low-grade heat energy from multiple sources for waste heat recovery. The specific recovery path is as follows: Waste heat from hydrogen electrolysis cell: The low-temperature waste heat water generated during the operation of hydrogen electrolysis cell 31 is injected into low-pressure low-temperature heat storage tank 42 through valve 9 35 and pump 9 38 in sequence.

[0032] Waste heat from fuel cells: The waste heat water generated by the operation of hydrogen fuel cell 30 is injected into low-pressure low-temperature heat storage tank 42 through valve 6 32 and pump 8 37 in sequence.

[0033] Photovoltaic waste heat: The hot water generated by the photovoltaic thermal module 40 (such as PV / T module) is injected into the low-pressure low-temperature heat storage tank 42 through valve 11 39 and pump 11 41 in sequence.

[0034] 3. Low-temperature heat energy distribution and geothermal coupling module: Hot water in the low-pressure low-temperature storage tank 42 is output and utilized through three paths: Path 1 (Low-temperature heating): Hot water enters the primary inlet of the low-temperature heat load heat exchanger 43 via valve 13 48, and after releasing heat, it is discharged (or returned) through pump 12 47 via the outlet. The secondary side of the low-temperature heat load heat exchanger 43 forms a closed heating loop: the outlet is connected to pump 11 44, flows through the low-temperature heat load 45 (such as building heating), and returns to the secondary inlet via valve 12 46.

[0035] Path 2 (Heat Pump Heat Source): Hot water is preheated through geothermal well 28 (using geothermal energy to raise the water temperature), and then pumped by pump six 27 to the primary side inlet of heat pump evaporator 20 to heat the heat pump working fluid. After that, it flows out from the outlet and returns to the low-pressure low-temperature heat storage tank 42 through valve fourteen 49.

[0036] Path 3 (Medium-temperature auxiliary heating): Hot water enters the primary side inlet of the medium-temperature heat load heat exchanger 12 through pump 7 29 and valve 5 25 in sequence, and is discharged after releasing heat to assist in the preheating of the medium-temperature heat load.

[0037] 4. Heat Pump Boosting and High-Pressure Thermal Storage Module: The heat pump unit is used to boost low-temperature thermal energy to medium- and high-temperature thermal energy. Its working fluid circulation loop is: heat pump evaporator 20 secondary side outlet -> heat pump compressor 23 -> heat pump condenser 22 primary side inlet -> primary side outlet -> heat pump expansion valve 21 -> heat pump evaporator 20 secondary side inlet. The heat generated by the heat pump is stored in a high-pressure thermal storage system. This system includes a high-pressure medium-temperature thermal storage tank 15 and a high-pressure low-temperature thermal storage tank 17. The thermal storage medium circulation path is as follows: the outlet medium of the high-pressure low-temperature thermal storage tank 17 passes through valve four 19 and pump five 26, enters the secondary side inlet of the heat pump condenser 22 to absorb heat, and after being heated, is injected into the high-pressure medium-temperature thermal storage tank 15. In addition, the CPC collector 24 serves as a supplementary heat source, using ambient cold water for heating, and then directly injects it into the high-pressure medium-temperature thermal storage tank 15 via valve two 14 and pump four 13.

[0038] 5. Medium-temperature thermal energy utilization and ORC power generation module: The high-temperature medium inside the high-pressure medium-temperature thermal storage tank 15 has two main utilization paths: Path 1 (Medium-temperature heating): The medium enters the primary side inlet of the medium-temperature heat load heat exchanger 210, and returns to the high-pressure low-temperature heat storage tank 17 after releasing heat. The secondary side circuit of the medium-temperature heating is as follows: Secondary side outlet of medium-temperature heat load heat exchanger 210 -> Pump 39 -> Medium-temperature heat load 52 -> Valve 11 -> Secondary side inlet of medium-temperature heat load heat exchanger 12 (where heat from the low-temperature side is absorbed) -> Secondary side outlet -> Return to the inlet of medium-temperature heat load heat exchanger 210.

[0039] Path 2 (ORC power generation): The medium enters the primary side inlet of ORC evaporator 16, heats the organic working fluid, and then flows back to the high-pressure low-temperature heat storage tank 17 through valve 3 18.

[0040] The working fluid cycle of the ORC power generation system is as follows: The organic working fluid absorbs heat and evaporates on the secondary side of the ORC evaporator 16, then enters the expander 7 to perform work, driving the ORC generator 8 to generate electricity. The exhaust gas after performing work passes sequentially through the primary side of the regenerator 6 and the primary side of the ORC condenser 4 to condense into a liquid state. The liquid working fluid is pressurized by pump 5, flows through the secondary side of the regenerator 6 for preheating, and finally returns to the ORC evaporator 16. The cooling side of the ORC condenser 4 utilizes ambient cold water, which enters through the secondary side inlet, exchanges heat, and is discharged by pump 3.

[0041] 6. System Operation Strategy The core operation strategy of this system is as follows: When there is a power surplus: the surplus power is used first to drive the heat pump compressor 23 to improve the low-grade heat energy and store it in the high-pressure medium-temperature heat storage tank 15; if there is still a surplus, the hydrogen electrolysis cell 31 is started to produce hydrogen and store it in the hydrogen storage tank 50.

[0042] When power is insufficient: prioritize starting the hydrogen fuel cell 30 to generate electricity; if the power is still insufficient, use the heat energy in the high-pressure medium-temperature heat storage tank 15 to start the ORC power generation system for supplementary power generation.

[0043] Thermal Energy Guarantee: Regardless of power availability, the system always prioritizes the heat supply to the thermal storage tank. Through multiple safeguards including geothermal energy, waste heat recovery, and heat pumps, the system ensures continuous operation of the heating system.

Claims

1. A multi-energy complementary based thermal dominant island integrated energy system, characterized in that, comprising The power supply unit includes a wind turbine (1) and a photovoltaic thermal assembly (40), which is connected to an isolated power grid (53) to supply power to it; The hydrogen energy subsystem includes a hydrogen electrolyzer (31), a hydrogen storage tank (50), and a hydrogen fuel cell (30); the hydrogen electrolyzer (31) is powered by the isolated power grid (53), and its hydrogen outlet is connected to the hydrogen storage tank (50) through valve eight (34); the hydrogen storage tank (50) is respectively connected to the hydrogen load (51) through valve ten (36) and to the hydrogen fuel cell (30) through valve seven (33); The waste heat recovery and low-temperature thermal storage subsystem includes a low-pressure low-temperature thermal storage tank (42); the waste heat output ends of the photovoltaic thermal assembly (40), the hydrogen electrolyzer (31), and the hydrogen fuel cell (30) are respectively connected to the inlet of the low-pressure low-temperature thermal storage tank (42) through pipelines; The heat pump coupled geothermal subsystem includes a heat pump unit and a geothermal well (28); one outlet of the low-pressure low-temperature thermal storage tank (42) is connected to the evaporator side of the heat pump unit after being heated by the geothermal well (28); The high-pressure thermal storage and medium-temperature heat supply subsystem includes a high-pressure medium-temperature thermal storage tank (15) and a high-pressure low-temperature thermal storage tank (17); the condenser side of the heat pump unit is connected between the high-pressure low-temperature thermal storage tank (17) and the high-pressure medium-temperature thermal storage tank (15); the high-pressure medium-temperature thermal storage tank (15) is connected with a CPC collector (24); the high-pressure medium-temperature thermal storage tank (15) supplies heat to the medium-temperature heat load (52) through the medium-temperature heat load heat exchanger two (10). The ORC power generation system includes an ORC evaporator (16), an expander (7), an ORC generator (8), and an ORC condenser (4); the outlet of the high-pressure medium-temperature thermal storage tank (15) is connected to the primary side inlet of the ORC evaporator (16).

2. The multi-energy complementary based thermal dominant island integrated energy system according to claim 1, wherein, The specific connection mode of the waste heat recovery and low-temperature thermal storage subsystem is that the waste heat hot water outlet of the hydrogen electrolyzer (31) is connected to the low-pressure low-temperature thermal storage tank (42) through valve nine (35) and pump nine (38) in sequence; the waste heat hot water outlet of the hydrogen fuel cell (30) is connected to the low-pressure low-temperature thermal storage tank (42) through valve six (32) and pump eight (37) in sequence; the hot water outlet of the photovoltaic thermal assembly (40) is connected to the low-pressure low-temperature thermal storage tank (42) through valve eleven (39) and pump ten (41) in sequence. 3.The multi-energy complementary thermal dominant island integrated energy system based on claim 1, wherein, The low-pressure low-temperature thermal storage tank (42) has three outputs: the first output is connected to the primary side inlet of the low-temperature heat load heat exchanger (43) through valve thirteen (48), and after heat exchange, it is discharged through pump twelve (47); the low-temperature heat load (45) is connected in the secondary side circuit of the low-temperature heat load heat exchanger (43); the second output is heated by the geothermal well (28), then enters the primary side inlet of the heat pump evaporator (20) through pump six (27), and after heat exchange, it is returned to the low-pressure low-temperature thermal storage tank (42) through valve fourteen (49); the third output enters the primary side inlet of the medium-temperature load heat exchanger one (12) through pump seven (29) and valve five (25) in sequence, and after heat exchange, it is discharged.

4. The multi-energy complementary based thermal dominant island integrated energy system according to claim 3, wherein, The heat supply circuit of the low-temperature heat load (45) is that the secondary side outlet of the low-temperature heat load heat exchanger (43) is connected with pump eleven (44), and the heat supply circuit of the low-temperature heat load (45) and valve twelve (46) is connected with the secondary side inlet of the low-temperature heat load heat exchanger (43).

5. The multi-energy complementary based thermal dominant island integrated energy system of claim 1, wherein, The circulating loop of the heat pump unit comprises that the secondary side outlet of the heat pump evaporator (20) is connected with the inlet of the compressor (23), the outlet of the compressor (23) is connected with the primary side inlet of the heat pump condenser (22), the outlet of the heat pump condenser (22) is connected with the secondary side inlet of the heat pump evaporator (20) through the heat pump expansion valve (21). 6.The multi-energy complementary thermal dominant island integrated energy system based on claim 1, wherein, The connection mode of the high-pressure heat storage and the medium-temperature heat supply subsystem is that the outlet of the high-pressure low-temperature heat storage tank (17) is connected with the secondary side inlet of the heat pump condenser (22) through valve four (19) and pump five (26), and the secondary side outlet of the heat pump condenser (22) is connected with the high-pressure medium-temperature heat storage tank (15). 7.The multi-energy complementary thermal dominant island integrated energy system based on claim 1, wherein, The heat output path of the high-pressure medium-temperature heat storage tank (15) comprises that one path is connected with the primary side inlet of the ORC evaporator (16), and the outlet is connected with the high-pressure low-temperature heat storage tank (17) through valve three (18); another path is connected with the primary side inlet of the medium-temperature heat load heat exchanger two (10), and the outlet is connected with the high-pressure low-temperature heat storage tank (17); the CPC collector (24) is heated by the ambient cold water, and is connected with the high-pressure medium-temperature heat storage tank (15) through valve two (14) and pump four (13).

8. The multi-energy complementary based thermal dominant island integrated energy system according to claim 7, wherein, The heat supply circuit of the medium-temperature heat load (52) is that the secondary side outlet of the medium-temperature heat load heat exchanger two (10) is sequentially connected with pump three (9), the medium-temperature heat load (52) and valve one (11), and enters the secondary side inlet of the medium-temperature heat load heat exchanger one (12), and the outlet returns to the secondary side inlet of the medium-temperature heat load heat exchanger two (10). 9.The multi-energy complementary based thermal dominant island integrated energy system of claim 1, wherein, The circulating loop of the ORC power generation system is that the secondary side outlet of the ORC evaporator (16) is connected with the expander (7), the expander (7) is connected with the ORC generator (8); the outlet of the expander (7) is sequentially connected with the primary side of the regenerator (6), the primary side of the ORC condenser (4) and pump two (5), and then returns to the secondary side inlet of the ORC evaporator (16) through the secondary side of the regenerator (6); the secondary side of the ORC condenser (4) is cooled by the ambient cold water, and is discharged through pump one (3).

10. A method for operating a multi-energy complementary thermal dominant island integrated energy system based on the multi-energy complementary thermal dominant island integrated energy system according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: When the system has power surplus, the compressor (23) of the heat pump system is preferentially driven to heat and store heat in the high-pressure medium-temperature heat storage tank (15); if there is still surplus power, the hydrogen electrolysis cell (31) is started to generate and store hydrogen; when the system has power shortage, the hydrogen fuel cell (30) is preferentially started to generate power; if the power is still insufficient, the ORC power generation system is started to generate supplementary power by using the heat of the high-pressure medium-temperature heat storage tank (15).

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