Waste mine energy station integrating power generation, energy storage and combined cooling and heating

Abstract

The invention discloses a waste mine energy station integrating power generation, energy storage and combined cooling and heating. Comprising wind power photovoltaic power generation equipment, an electric heater, an electric heating hot water tank, an electric heating cold water tank, a motor set, a compressor, an interstage cooler, an expansion unit, a generator set, an interstage heater, a heat recovery cold water tank, a heat recovery hot water tank, an ORC power generation system, a heating heat exchanger, a refrigeration expansion machine, a waste mine underground roadway, a gas conveying pipe, a water conveying pipe and a settlement area artificial lake. The device not only can improve the efficiency of the expansion machine and the generator, but also can efficiently utilize the underground space to improve the energy storage density; ground power generation and underground space energy storage are achieved, and the abandoned mine field can be converted into a new energy base integrating power generation and power storage. The interstage compression heat of compressed air energy storage can be used for heating, the characteristics of the expansion machine can be used for refrigerating, and combined cooling, heating and power supply is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of renewable energy power generation with energy storage and efficient utilization of abandoned mines, and particularly to an abandoned mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply. Background Art

[0002] As of October 2023, the installed capacities of solar power generation and wind power in China have exceeded 900 million kilowatts. Due to their inherent intermittent instability, the large-scale connection of photovoltaic and wind power makes the operation and dispatching of the power grid more complex. Energy storage is not only the best measure to solve the above problems, but also can further expand the installed capacity of renewable energy and increase the penetration rate of renewable energy in the power grid. However, at present, high-efficiency, low-cost, and large-capacity energy storage technologies are the bottleneck constraints.

[0003] By 2030, there will be 15,000 abandoned coal mines in China, and the corresponding abandoned underground space will reach 900 million m 3 . Using the abandoned underground space for energy storage not only has a low construction cost but also can solve the land occupation problem, providing a feasible solution for renewable energy power generation with energy storage. The existing energy storage in abandoned underground spaces mainly adopts pumped-storage hydroelectricity and compressed air energy storage. The main problem faced by pumped-storage hydroelectricity in underground spaces is the low energy storage density. For compressed air energy storage in underground spaces, the current main mode is constant-volume energy storage, that is, using the underground space as a closed storage tank. There are mainly two problems with constant-volume compressed air energy storage. One is that there is still a large amount of gas remaining in the underground space after the energy release ends and cannot participate in doing work, resulting in a low energy storage density. The other is that the gas pressure in the underground space always changes during the energy storage and release process, causing the compressor and expander to always operate under variable working conditions, resulting in low system efficiency. Summary of the Invention

[0004] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide an abandoned mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply.

[0005] The present invention is realized through the following technical solutions: An abandoned mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply, comprising a wind power and photovoltaic power generation device, an electric heater, an electric heating hot water tank, an electric heating cold water tank, a motor set, a compressor, an inter-stage cooler, an expansion unit, a power generation unit, an inter-stage heater, a heat recovery cold water tank, a heat recovery hot water tank, an ORC power generation system, a heating heat exchanger, a refrigeration expander, an abandoned mine underground roadway, a gas pipeline, a water pipeline, and a sedimentation area artificial lake; the wind power and photovoltaic power generation device is respectively connected to the electric heater and the motor set, the compressor is respectively connected to the motor set and the inter-stage cooler, and the inter-stage cooler is respectively connected to the heat recovery cold water tank and the heat recovery hot water tank; the electric heating hot water tank is respectively connected to the electric heater and the inter-stage heater, the electric heating cold water tank is respectively connected to the electric heater and the inter-stage heater, the expansion unit is respectively connected to the inter-stage heater and the power generation unit, and the refrigeration expander is connected to the expansion unit; the ORC power generation system is respectively connected to the heat recovery cold water tank, the heat recovery hot water tank, and the sedimentation area artificial lake; the heating heat exchanger is respectively connected to the ORC power generation system, the heat recovery cold water tank, and the heat recovery hot water tank; the inter-stage heater is connected to the inter-stage cooler in parallel and then connected to the abandoned mine underground roadway through the gas pipeline, and the sedimentation area artificial lake is communicated with the abandoned mine underground roadway through the water pipeline; the abandoned mine underground roadway and the water pipeline are surrounded by the surrounding rock, and the height of the abandoned mine underground roadway is lower than that of the sedimentation area artificial lake.

[0006] The abandoned mine underground roadway, the gas pipeline, the water pipeline, and the sedimentation area artificial lake form a constant-pressure energy storage and energy release system for gas-driven water and water-driven gas; the sedimentation area artificial lake can hold the water required for the energy storage and release process. During energy storage, gas drives water, and constant-pressure gas storage is achieved through the liquid column static pressure of the water pipeline; during energy release, water drives gas, and constant-pressure gas release is also achieved through the liquid column static pressure of the water pipeline.

[0007] It also includes an electric heating hot water pump, an electric heating cold water pump, and a second gas valve; the inter-stage heater includes a first inter-stage heater, a second inter-stage heater, and a third inter-stage heater; the inlet of the electric heating hot water tank is connected to the electric heater, and its outlet is connected to the inlet of the electric heating hot water pump. The outlet of the electric heating hot water pump is respectively connected to the water side inlet ends of the three inter-stage heaters, namely the first inter-stage heater, the second inter-stage heater, and the third inter-stage heater; the water side outlet ends of the three inter-stage heaters, namely the first inter-stage heater, the second inter-stage heater, and the third inter-stage heater, are all connected to the inlet of the electric heating cold water tank. The outlet of the electric heating cold water tank is connected to the inlet of the electric heating cold water pump, and the outlet of the electric heating cold water pump is connected to the electric heater; the expansion unit includes a first expander, a second expander, and a third expander; the inlet of the first expander is connected to the gas side outlet of the first inter-stage heater, the inlet of the second expander is connected to the gas side outlet of the second inter-stage heater, and the inlet of the third expander is connected to the gas side outlet of the third inter-stage heater; the outlet of the first expander is connected to the gas side inlet of the first inter-stage heater, the outlet of the second expander is connected to the gas side inlet of the second inter-stage heater, and the outlet of the third expander is connected to the atmosphere; the first expander, the second expander, and the third expander are coaxially connected and connected to the generator set to jointly drive the generator set; the outlet of the second gas valve is connected to the gas side inlet of the first inter-stage heater, and the inlet of the second gas valve is connected to the underground roadway of the abandoned mine through the gas pipeline.

[0008] It also includes a heat recovery hot water pump, a heat recovery cold water pump, a first gas valve, a third gas valve, a first hot water valve and a second hot water valve; the compressor includes a first compressor, a second compressor and a third compressor; the first compressor, the second compressor and the third compressor are coaxially connected and connected to the motor set; the inter-stage cooler includes a first inter-stage cooler, a second inter-stage cooler and a third inter-stage cooler; the outlet of the first compressor is connected to the gas-side inlet of the first inter-stage cooler, the outlet of the second compressor is connected to the gas-side inlet of the second inter-stage cooler, and the outlet of the third compressor is connected to the gas-side inlet of the third inter-stage cooler; the inlet of the second compressor is connected to the gas-side outlet of the second inter-stage cooler, the inlet of the third compressor is connected to the gas-side outlet of the third inter-stage cooler, and the inlet of the first compressor is connected to the atmosphere; the outlet of the heat recovery cold water pump is respectively connected to the water-side inlets of the three inter-stage coolers, namely the first inter-stage cooler, the second inter-stage cooler and the third inter-stage cooler, and the inlet of the heat recovery cooling pump is connected to the outlet of the heat recovery cold water tank; the outlet of the first gas valve and the inlet of the second gas valve are connected in parallel on the gas transmission pipe and are connected to the underground roadway of the abandoned mine through the gas transmission pipe, and the inlet of the first gas valve is connected to the gas-side outlet of the third inter-stage cooler; the inlet of the heat recovery hot water tank is respectively connected to the water-side inlets of the three inter-stage coolers, namely the first inter-stage cooler, the second inter-stage cooler and the third inter-stage cooler, and the outlet of the heat recovery hot water tank is connected to the inlet of the heat recovery hot water pump; the first hot water valve and the second hot water valve are arranged in parallel, and the inlets of the two hot water valves are both connected to the outlet of the heat recovery hot water pump; the inlet of the heating heat exchanger is connected to the outlet of the second hot water valve, and the outlet of the heating heat exchanger is connected to the heat recovery cold water tank; the ORC power generation system includes an ORC evaporator, an ORC working fluid pump, an ORC expander, an ORC condenser, an ORC cold water pump and an ORC cold water pipe; the water-side inlet of the ORC evaporator is connected to the outlet of the first hot water valve, and the water-side outlet of the ORC evaporator is connected to the heat recovery cold water tank; the inlet of the ORC expander is connected to the working fluid-side outlet of the ORC evaporator, and the outlet of the ORC expander is connected to the working fluid-side inlet of the ORC condenser; the inlet of the ORC working fluid pump is connected to the working fluid-side outlet of the ORC condenser, and the outlet of the ORC working fluid pump is connected to the working fluid-side inlet of the ORC evaporator; the inlet of the ORC cold water pump is connected to the artificial lake in the sedimentation area, and the outlet of the ORC cold water pump is connected to the water-side inlet of the ORC condenser; the inlet of the ORC cold water pipe is connected to the water-side outlet of the ORC cold water pipe, and the outlet of the ORC cold water pipe is connected to the artificial lake in the sedimentation area; the inlet of the third gas valve is connected to the outlet of the second expander, and the outlet of the third gas valve is connected to the inlet of the refrigeration expander.

[0009] The wind power and photovoltaic power generation equipment is installed on the artificial lake in the settlement area or at a land location in the abandoned mine.

[0010] The electric energy of the wind power and photovoltaic power generation equipment is divided into three paths. The first path is connected to the power grid, the second path is connected to the motor set, and the third path is connected to the electric heater.

[0011] The underground roadway of the abandoned mine stores energy in a constant-pressure manner. The gas transmission pipe is connected to the highest point of the underground roadway of the abandoned mine, and the water transmission pipe is connected to the lowest point of the underground roadway of the abandoned mine.

[0012] When the device is in the combined heat and power supply mode, during the heating season, the inter-stage compression heat is recovered. Part of the hot water drives the heating heat exchanger to supply heat, and the other part of the hot water drives the ORC power generation system to generate electricity for heating. During the non-heating season, all the hot water enters the ORC power generation system to generate electricity. When the device is in the combined cooling and power supply mode, the expansion characteristics of the expansion unit are used for refrigeration to achieve combined cooling and power supply.

[0013] Compared with the prior art, the advantages of the present invention are as follows: The present device proposes a scheme of constant-pressure compressed air energy storage. During energy storage, the high-pressure gas drives the water in the underground space (the underground roadway of the abandoned mine) to the artificial lake in the settlement area, and when the energy is released, the water in the artificial lake in the settlement area flows into the underground space (the underground roadway of the abandoned mine) to drive the high-pressure gas away for work, and constant-pressure energy storage is achieved through the liquid column static pressure of the water transmission pipe. Constant-pressure energy storage can not only improve the efficiency of the expander and the generator, but also efficiently utilize the underground space to increase the energy storage density. The ground space of the abandoned mine is large, and wind power or photovoltaic can be arranged to achieve on-ground power generation and underground space energy storage, and the abandoned mine can be transformed into a new energy base integrating power generation and energy storage. In addition, the inter-stage compression heat of compressed air energy storage can be used for heating, and the characteristics of the expander can be used for refrigeration to achieve combined cooling, heat and power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0015] Meanings of the reference signs in the figures: 1. Wind power and photovoltaic power generation equipment; 2. Electric heater; 3. Electric heating hot water tank; 4. Electric heating hot water pump; 5. Electric heating cold water pump; 6. Electric heating cold water tank; 7. First-stage intermediate heater; 8. Second-stage intermediate heater; 9. Third-stage intermediate heater; 10. Generator set; 11. Third expander; 12. Second expander; 13. First expander; 14. Second gas valve; 15. First gas valve; 16. Third compressor; 17. Second compressor; 18. First compressor; 19. Motor set; 20. First-stage intermediate cooler; 21. Second-stage intermediate cooler; 22. Third-stage intermediate cooler; 23. Heat recovery cold water tank; 24. Heat recovery cold water pump; 25. Gas pipeline; 26. Heat recovery hot water tank; 27. Heat recovery hot water pump; 28. First hot water valve; 29. Second hot water valve; 30. Heating heat exchanger; 31. ORC evaporator; 32. ORC working medium pump; 33. ORC expander; 34. ORC condenser; 35. ORC cold water pump; 36. ORC cold water pipe; 37. Third gas valve; 38. Refrigeration expander; 39. Surrounding rock; 40. Abandoned mine underground roadway; 41. Water pipeline; 42. Artificial lake in the subsidence area. Detailed implementation manners

[0016] The content of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0017] Embodiment

[0018] Refer to Figure 1, which is a waste mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply, includes wind power and photovoltaic power generation equipment 1, electric heater 2, electric heating hot water tank 3, electric heating cold water tank 6, motor set 19, compressor, inter-stage cooler, expansion unit, generator set 10, inter-stage heater, heat recovery cold water tank 23, heat recovery hot water tank 26, ORC power generation system, heating heat exchanger 30, refrigeration expander 38, waste mine underground roadway 40, gas transmission pipe 25, water transmission pipe 41, artificial lake in the subsidence area 42; the wind power and photovoltaic power generation equipment 1 is respectively connected to the electric heater 2 and the motor set 19, the compressor is respectively connected to the motor set 19 and the inter-stage cooler, and the inter-stage cooler is respectively connected to the heat recovery cold water tank 23 and the heat recovery hot water tank 26; the electric heating hot water tank 3 is respectively connected to the electric heater 2 and the inter-stage heater, the electric heating cold water tank 6 is respectively connected to the electric heater 2 and the inter-stage heater, the expansion unit is respectively connected to the inter-stage heater and the generator set 10, and the refrigeration expander 38 is connected to the expansion unit; the ORC power generation system is respectively connected to the heat recovery cold water tank 23, the heat recovery hot water tank 26, and the artificial lake in the subsidence area 42; the heating heat exchanger 30 is respectively connected to the ORC power generation system, the heat recovery cold water tank 23, and the heat recovery hot water tank 26; the inter-stage heater is connected to the inter-stage cooler in parallel and then connected to the waste mine underground roadway 40 through the gas transmission pipe 25, and the artificial lake in the subsidence area 42 is communicated with the waste mine underground roadway 40 through the water transmission pipe 41; the waste mine underground roadway 40 and the water transmission pipe 41 are surrounded by the surrounding rock 39, and the waste mine underground roadway 40 is lower than the height of the artificial lake in the subsidence area 42.

[0019] The waste mine underground roadway 40, gas transmission pipe 25, water transmission pipe 41, and artificial lake in the subsidence area 42 form a constant-pressure energy storage and energy release system for gas-driven water and water-driven gas; the artificial lake in the subsidence area 42 can hold the water required for the energy storage and release process. During energy storage, gas drives water, and constant-pressure gas storage is achieved through the liquid column static pressure of the water transmission pipe 41; during energy release, water drives gas, and constant-pressure gas release is also achieved through the liquid column static pressure of the water transmission pipe 41.

[0020] It further includes an electric heating hot water pump 4, an electric heating cold water pump 5, and a second gas valve 14; the inter-stage heaters include a first inter-stage heater 7, a second inter-stage heater 8, and a third inter-stage heater 9; the inlet of the electric heating hot water tank 3 is connected to the electric heater 2, and its outlet is connected to the inlet of the electric heating hot water pump 4. The outlet of the electric heating hot water pump 4 is respectively connected to the water-side inlet ends of the three inter-stage heaters, namely the first inter-stage heater 7, the second inter-stage heater 8, and the third inter-stage heater 9; the water-side outlet ends of the three inter-stage heaters, namely the first inter-stage heater 7, the second inter-stage heater 8, and the third inter-stage heater 9, are all connected to the inlet of the electric heating cold water tank 6. The outlet of the electric heating cold water tank 6 is connected to the inlet of the electric heating cold water pump 5, and the outlet of the electric heating cold water pump 5 is connected to the electric heater 2; the expansion unit includes a first expander 13, a second expander 12, and a third expander 11; the inlet of the first expander 13 is connected to the gas-side outlet of the first inter-stage heater 7, the inlet of the second expander 12 is connected to the gas-side outlet of the second inter-stage heater 8, and the inlet of the third expander 11 is connected to the gas-side outlet of the third inter-stage heater 9; the outlet of the first expander 13 is connected to the gas-side inlet of the first inter-stage heater 7, the outlet of the second expander 12 is connected to the gas-side inlet of the second inter-stage heater 8, and the outlet of the third expander 11 is connected to the atmosphere; the first expander 13, the second expander 12, and the third expander 11 are coaxially connected and connected to the generator set 10 to jointly drive the generator set 10; the outlet of the second gas valve 14 is connected to the gas-side inlet of the first inter-stage heater 7, and the inlet of the second gas valve 14 is connected to the underground roadway 40 of the abandoned mine through the gas pipeline 25.

[0021] It also includes a heat recovery hot water pump 27, a heat recovery cold water pump 24, a first gas valve 15, a third gas valve 37, a first hot water valve 28 and a second hot water valve 29; the compressor includes a first compressor 18, a second compressor 17 and a third compressor 16; the first compressor 18, the second compressor 17 and the third compressor 16 are coaxially connected and connected to the motor group 19; the inter-stage cooler includes a first inter-stage cooler 20, a second inter-stage cooler 21 and a third inter-stage cooler 22; the outlet of the first compressor 18 is connected to the gas side inlet of the first inter-stage cooler 20, the outlet of the second compressor 17 is connected to the gas side inlet of the second inter-stage cooler 21, and the outlet of the third compressor 16 is connected to the gas side inlet of the third inter-stage cooler 22; the inlet of the second compressor 17 is connected to the gas side outlet of the second inter-stage cooler 21, the inlet of the third compressor 16 is connected to the gas side outlet of the third inter-stage cooler 22, and the inlet of the first compressor 18 is connected to the atmosphere; the outlet of the heat recovery cold water pump 24 is respectively connected to the water side inlets of the three inter-stage coolers, namely the first inter-stage cooler 20, the second inter-stage cooler 21 and the third inter-stage cooler 22, and the inlet of the heat recovery cooling pump is connected to the outlet of the heat recovery cold water tank 23; the outlet of the first gas valve 15 and the inlet of the second gas valve 14 are connected in parallel on the gas transmission pipe 25 and are connected to the abandoned mine underground roadway 40 through the gas transmission pipe 25, and the inlet of the first gas valve 15 is connected to the gas side outlet of the third inter-stage cooler 22; the inlet of the heat recovery hot water tank 26 is respectively connected to the water side inlets of the three inter-stage coolers, namely the first inter-stage cooler 20, the second inter-stage cooler 21 and the third inter-stage cooler 22, and the outlet of the heat recovery hot water tank 26 is connected to the inlet of the heat recovery hot water pump 27; the first hot water valve 28 and the second hot water valve 29 are arranged in parallel, and the inlets of the two hot water valves are both connected to the outlet of the heat recovery hot water pump 27; the inlet of the heating heat exchanger 30 is connected to the outlet of the second hot water valve 29, and the outlet of the heating heat exchanger 30 is connected to the heat recovery cold water tank 23; the ORC power generation system includes an ORC evaporator 31, an ORC working fluid pump 32, an ORC expander 33, an ORC condenser 34, an ORC cold water pump 35 and an ORC cold water pipe 36; the water side inlet of the ORC evaporator 31 is connected to the outlet of the first hot water valve 28, and the water side outlet of the ORC evaporator 31 is connected to the heat recovery cold water tank 23; the inlet of the ORC expander 33 is connected to the working fluid side outlet of the ORC evaporator 31, and the outlet of the ORC expander 33 is connected to the working fluid side inlet of the ORC condenser 34; the inlet of the ORC working fluid pump 32 is connected to the working fluid side outlet of the ORC condenser 34, and the outlet of the ORC working fluid pump 32 is connected to the working fluid side inlet of the ORC evaporator 31; the inlet of the ORC cold water pump 35 is connected to the artificial lake 42 in the sedimentation area, and the outlet of the ORC cold water pump 35 is connected to the water side inlet of the ORC condenser 34; the inlet of the ORC cold water pipe 36 is connected to the water side outlet of the ORC cold water pipe 36, and the outlet of the ORC cold water pipe 36 is connected to the artificial lake 42 in the sedimentation area;The inlet of the third gas valve 37 is connected to the outlet of the second expander 12, and the outlet of the third gas valve 37 is connected to the inlet of the refrigeration expander 38.;

[0022] The wind and solar power generation equipment 1 is installed on the artificial lake 42 in the subsidence area or at a land location in an abandoned mine.

[0023] The electric energy of the wind and solar power generation equipment 1 is divided into three paths. The first path is connected to the power grid, the second path is connected to the motor set 19, and the third path is connected to the electric heater 2.

[0024] The underground roadway 40 of the abandoned mine stores energy in a constant pressure mode. The gas transmission pipe 25 is connected to the highest point of the underground roadway 40 of the abandoned mine, and the water transmission pipe 41 is connected to the lowest point of the underground roadway 40 of the abandoned mine. The uppermost end of the water transmission pipe 41 is connected to the artificial lake 42 in the subsidence area, and the wind and solar power generation equipment 1 can be arranged in the artificial lake 42 in the subsidence area.

[0025] When the device is in the combined heat and power supply mode, in the heating season, the inter-stage compression heat is recovered, and part of the hot water drives the heating heat exchanger 30 to supply heat, and the other part of the hot water drives the ORC power generation system to generate electricity for heating; in the non-heating season, all the hot water enters the ORC power generation system to generate electricity; when the device is in the combined cooling and power supply mode, the expansion characteristics of the expansion unit are used for refrigeration to achieve combined cooling and power supply.

[0026] In this embodiment, the ORC power generation system, also known as the organic Rankine power generation system, or the organic Rankine cycle power generation system. The organic Rankine cycle (Organic Rankine Cycle, abbreviated as ORC) is a Rankine cycle with low-boiling organic substances as the working fluid, mainly consisting of a waste heat boiler (or heat exchanger), a turbine, a condenser, and a working fluid pump. The organic working fluid absorbs heat from the waste heat flow in the heat exchanger to generate steam with a certain pressure and temperature. The steam enters the turbomachinery to expand and do work, thereby driving a generator or driving other power machinery. The steam discharged from the turbine releases heat to the cooling water in the condenser and condenses into a liquid state. Finally, it returns to the heat exchanger with the help of the working fluid pump, and so on, continuously circulating. In the conventional steam Rankine cycle, the working fluid is steam, which consists of four major devices: a boiler, a steam turbine, a condenser, and a feed water pump. The working fluid continuously undergoes four processes of isobaric heating, adiabatic expansion, isobaric heat release, and adiabatic compression in the thermal equipment, so that the thermal energy is continuously converted into mechanical energy. When using low-temperature organic working fluids as the working fluid of the cycle, the main equipment includes: an evaporator, an expander, a condenser, and a circulation pump, etc. The ORC technology is not only used in the waste heat power plants of cement factories but also in other industries.

[0027] The working principle of this embodiment is: a wind power photovoltaic power generation device 1 is arranged on the ground of an abandoned mine or on an artificial lake 42 in a settlement area to realize renewable energy power generation. In order to solve the huge volatility of the output of electric energy from renewable energy power generation, the underground space of the abandoned mine (the underground tunnel 40 of the abandoned mine) is used for compressed air energy storage to realize ground power generation and underground energy storage, and to transform the abandoned mine into a new energy power base. When the power demand is low, the renewable energy power from the abandoned mine drives the compressor to convert the power into high-pressure air and store it in the abandoned underground space (the underground tunnel 40 of the abandoned mine). When the power demand is peak, the high-pressure air in the underground space (the underground tunnel 40 of the abandoned mine) is released to drive the expansion unit to generate power. The abandoned underground space (the underground tunnel 40 of the abandoned mine), the water pipe 41 and the artificial lake 42 in the settlement area form a constant pressure gas storage system, and the static pressure of the liquid column of the water pipe 41 is used to realize the constant pressure operation of the energy storage system. When storing energy, the high-pressure gas drives the water in the underground space (abandoned mine underground tunnel 40) to the artificial lake 42 in the settlement area for storage, and when releasing energy, the water in the artificial lake 42 in the settlement area drives the high-pressure gas in the underground space (abandoned mine underground tunnel 40) out and then generates power. The recovered interstage compression heat can be used for winter heating or drive the organic Rankine (ORC) power generation system, and the final stage expander has the ability of expansion refrigeration, which can provide cold energy for users in summer.

[0028] The electric energy from the wind power and photovoltaic power generation equipment 1 drives the motor group 19 and the electric heater 2 at the same time, wherein the relatively stable part of the electric energy drives the motor group 19 to convert the electric energy into gas potential energy; and the part of the electric energy with larger fluctuations drives the electric heater 2 to convert the electric energy into thermal energy, which is used to heat the intake air of the expansion unit when releasing energy, and the renewable energy electric energy with large fluctuations and instability is converted into potential energy and thermal energy respectively for storage, thereby avoiding wind and solar power abandonment and improving system efficiency.

[0029] Compressed air energy storage in the underground space of abandoned mines is most suitable for solving the energy storage problem of distributed renewable energy generation, and abandoned mines are most suitable for arranging renewable energy generators 10, such as wind power or photovoltaics, due to their large area. The combination of ground power generation and underground power storage can perfectly transform abandoned mines into a renewable energy supply base integrating power generation and storage, providing strong support for increasing the proportion of renewable energy power generation and building a new power system.

[0030] A large amount of interstage compression heat can be used for winter heating, providing an option for increasing the proportion of renewable energy heating in the north. In addition, the expander can provide cold energy in summer, with a simple structure and low investment, providing strong support for the combined supply of heat and cold in cold winter and hot summer areas.

[0031] This embodiment can operate in grid-connected power generation, energy storage, energy release, combined heat and power, and combined cooling and power modes.

[0032] Grid-connected power generation mode: The wind power and photovoltaic power generation equipment 1 (wind power or photovoltaic units) arranged on the land of abandoned mines or the artificial lake 42 in the subsidence area generates electricity. When the power grid can accommodate this amount of electricity, it is directly grid-connected.

[0033] Energy storage mode: During the low power demand period, the relatively stable part of the electrical energy of the wind power and photovoltaic power generation equipment 1 (wind power or photovoltaic units) drives the compressor to convert the electrical energy into the potential energy of gas and store it in the underground roadway 40 of the abandoned mine. The part of the electrical energy with large fluctuations that is not suitable for driving power equipment is used to drive the electric heater 2 to convert the electrical energy into heat energy and store it in the hot water tank. During energy storage, the high-pressure gas enters the underground roadway 40 of the abandoned mine through the gas pipeline 25, and gradually drives the water in the roadway out through the water pipeline 41 to be stored in the artificial lake 42 in the subsidence area. Since the gas pipeline 25 is connected to the highest point of the underground roadway, and the water pipeline 41 is connected to the lowest point of the underground roadway, through reasonable design, all or almost all of the water in the underground roadway can be driven out to the artificial lake 42 in the subsidence area, realizing the efficient utilization of underground space. And due to the hydrostatic pressure of the water column in the water pipeline 41, that is, the water seal effect of a certain height, constant-pressure gas storage is achieved, improving the efficiency of the compressor. During the process of converting the electrical energy with large fluctuations into heat energy, the electric heating cold water pump 5 pumps the cold water in the electric heating cold water tank 6 into the electric heater 2, and after being heated by the electric heater 2, it becomes hot water and is then stored in the electric heating hot water tank 3. At the same time, during the energy storage process, a large amount of inter-stage compression heat is generated by the compressor. The heat recovery cold water pump 24 pumps the cold water in the heat recovery cold water tank 23 into the inter-stage cooler for heat recovery. The recovered inter-stage compression heat enters the heat recovery hot water tank 26 for storage.

[0034] Energy release mode: During the peak power demand period, the water in the artificial lake 42 in the subsidence area enters the underground roadway 40 of the abandoned mine through the water pipeline 41, driving the high-pressure air in the roadway out of the roadway and entering the expander through the gas pipeline 25 to do work and generate electricity. Since the water pipeline 41 and the gas pipeline 25 are respectively connected to the lowest point and the highest point of the underground roadway, the water can drive all or almost all of the gas out of the underground space, realizing the efficient energy storage and release of the underground space. The heat energy stored in the electric heating hot water tank 3 during the energy storage period is pumped out by the heat recovery hot water pump 27 during the energy release period and enters each inter-stage heater to increase the intake air temperature of the expander, thereby increasing the power generation power of the expander. The hot water that has cooled down after passing through the inter-stage heater becomes cold water and returns to the heat recovery cold water tank 23 for storage.

[0035] Combined heat and power supply mode: During the energy release period, in addition to the high-pressure gas released from the underground roadway 40 of the abandoned mine driving the expander to generate electricity, a large amount of hot water stored in the heat recovery hot water tank 26 can also be used for heating and driving the ORC power generation system. During the heating season, the heat recovery hot water pump 27 extracts hot water from the heat recovery hot water tank 26, and the hot water enters the heating heat exchanger 30 to dissipate heat to provide heat energy for the building. After the hot water cools down after dissipating heat in the heating heat exchanger 30, it becomes cold water and enters the heat recovery cold water tank 23 for storage. According to the size of the heating load, during the heating season, part of the hot water can be used to drive the heating heat exchanger 30 for heating, and the other part can be used to drive the ORC for power generation. During the non-heating season, all the hot water enters the ORC evaporator 31 to drive the ORC power generation system for power generation. After the hot water cools down after passing through the ORC evaporator 31, it becomes cold water and enters the heat recovery cold water tank 23 for storage. The cooling water of the ORC power generation system comes from the artificial lake 42 in the sedimentation area.

[0036] Combined cooling and power supply mode: In areas with hot summers and cold winters or in the southern regions, cooling energy is required in summer. During the energy release period, while the expander generates electricity, it can also utilize its expansion refrigeration characteristics to generate cooling energy in summer to meet user needs. During the energy release period, a gas is led out from the outlet of the second-stage expander and enters the refrigeration expander 38 to generate cooling energy while generating electricity, realizing combined cooling and power supply.

[0037] The above detailed description is for the specific description of the feasible embodiments of the present invention. These embodiments are not intended to limit the patent scope of the present invention. Any equivalent implementation or modification without departing from the present invention should be included in the patent scope of this case.

Claims

1. An abandoned mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply, characterized in that: Including wind power and photovoltaic power generation equipment, electric heaters, electric heating hot water tanks, electric heating cold water tanks, motor sets, compressors, inter-stage coolers, expansion units, power generation sets, inter-stage heaters, heat recovery cold water tanks, heat recovery hot water tanks, ORC power generation systems, heating heat exchangers, refrigeration expanders, underground roadways of abandoned mines, gas pipelines, water pipelines, artificial lakes in subsidence areas; the wind power and photovoltaic power generation equipment are respectively connected to the electric heaters and motor sets, the compressor is respectively connected to the motor sets and inter-stage coolers, the inter-stage coolers are respectively connected to the heat recovery cold water tanks and heat recovery hot water tanks; the electric heating hot water tank is respectively connected to the electric heater and inter-stage heater, the electric heating cold water tank is respectively connected to the electric heater and inter-stage heater, the expansion unit is respectively connected to the inter-stage heater and power generation set, the refrigeration expander is connected to the expansion unit; the ORC power generation system is respectively connected to the heat recovery cold water tank, heat recovery hot water tank and artificial lake in the subsidence area; the heating heat exchanger is respectively connected to the ORC power generation system, the heat recovery cold water tank and heat recovery hot water tank; the inter-stage heater is connected to the inter-stage cooler in parallel and then connected to the underground roadway of the abandoned mine through the gas pipeline, the artificial lake in the subsidence area is communicated with the underground roadway of the abandoned mine through the water pipeline; the underground roadway of the abandoned mine and the water pipeline are surrounded by surrounding rock, and the height of the underground roadway of the abandoned mine is lower than that of the artificial lake in the subsidence area.

2. The waste mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply according to claim 1, wherein: It also includes an electric heating hot water pump, an electric heating cold water pump, and a second gas valve; the inter-stage heater includes a first inter-stage heater, a second inter-stage heater, and a third inter-stage heater; the inlet of the electric heating hot water tank is connected to the electric heater, its outlet is connected to the inlet of the electric heating hot water pump, and the outlet of the electric heating hot water pump is respectively connected to the water side inlet ends of the three inter-stage heaters, namely the first inter-stage heater, the second inter-stage heater, and the third inter-stage heater; the water side outlet ends of the three inter-stage heaters, namely the first inter-stage heater, the second inter-stage heater, and the third inter-stage heater, are all connected to the inlet of the electric heating cold water tank, the outlet of the electric heating cold water tank is connected to the inlet of the electric heating cold water pump, and the outlet of the electric heating cold water pump is connected to the electric heater; the expansion unit includes a first expander, a second expander, and a third expander; the inlet of the first expander is connected to the gas side outlet of the first inter-stage heater, the inlet of the second expander is connected to the gas side outlet of the second inter-stage heater, and the inlet of the third expander is connected to the gas side outlet of the third inter-stage heater; the outlet of the first expander is connected to the gas side inlet of the first inter-stage heater, the outlet of the second expander is connected to the gas side inlet of the second inter-stage heater, and the outlet of the third expander is connected to the atmosphere; the first expander, the second expander, and the third expander are coaxially connected and connected to the generator set to jointly drive the generator set; the outlet of the second gas valve is connected to the gas side inlet of the first inter-stage heater, and the inlet of the second gas valve is connected to the underground roadway of the abandoned mine through the gas transmission pipe.

3. The waste mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply according to claim 2, characterized in that: It also includes a heat recovery hot water pump, a heat recovery cold water pump, a first gas valve, a third gas valve, a first hot water valve and a second hot water valve; the compressor includes a first compressor, a second compressor and a third compressor; the first compressor, the second compressor and the third compressor are coaxially connected and connected to the motor group; the inter-stage cooler includes a first inter-stage cooler, a second inter-stage cooler and a third inter-stage cooler; the outlet of the first compressor is connected to the gas side inlet of the first inter-stage cooler, the outlet of the second compressor is connected to the gas side inlet of the second inter-stage cooler, and the outlet of the third compressor is connected to the gas side inlet of the third inter-stage cooler; the inlet of the second compressor is connected to the gas side outlet of the second inter-stage cooler, the inlet of the third compressor is connected to the gas side outlet of the third inter-stage cooler, and the inlet of the first compressor is connected to the atmosphere; the outlet of the heat recovery cold water pump is respectively connected to the water side inlets of the three inter-stage coolers of the first inter-stage cooler, the second inter-stage cooler and the third inter-stage cooler, and the inlet of the heat recovery cooling pump is connected to the outlet of the heat recovery cold water tank; the outlet of the first gas valve and the inlet of the second gas valve are connected in parallel on the gas transmission pipe and connected to the underground roadway of the abandoned mine through the gas transmission pipe, and the inlet of the first gas valve is connected to the gas side outlet of the third inter-stage cooler; the inlet of the heat recovery hot water tank is respectively connected to the water side inlets of the three inter-stage coolers of the first inter-stage cooler, the second inter-stage cooler and the third inter-stage cooler, and the outlet of the heat recovery hot water tank is connected to the inlet of the heat recovery hot water pump; the first hot water valve and the second hot water valve are arranged in parallel, and the inlets of the two hot water valves are both connected to the outlet of the heat recovery hot water pump; the inlet of the heating heat exchanger is connected to the outlet of the second hot water valve, and the outlet of the heating heat exchanger is connected to the heat recovery cold water tank; the ORC power generation system includes an ORC evaporator, an ORC working fluid pump, an ORC expander, an ORC condenser, an ORC cold water pump and an ORC cold water pipe; the water side inlet of the ORC evaporator is connected to the outlet of the first hot water valve, and the water side outlet of the ORC evaporator is connected to the heat recovery cold water tank; the inlet of the ORC expander is connected to the working fluid side outlet of the ORC evaporator, and the outlet of the ORC expander is connected to the working fluid side inlet of the ORC condenser; the inlet of the ORC working fluid pump is connected to the working fluid side outlet of the ORC condenser, and the outlet of the ORC working fluid pump is connected to the working fluid side inlet of the ORC evaporator; the inlet of the ORC cold water pump is connected to the artificial lake in the sedimentation area, and the outlet of the ORC cold water pump is connected to the water side inlet of the ORC condenser; the inlet of the ORC cold water pipe is connected to the water side outlet of the ORC cold water pipe, and the outlet of the ORC cold water pipe is connected to the artificial lake in the sedimentation area; the inlet of the third gas valve is connected to the outlet of the second expander, and the outlet of the third gas valve is connected to the inlet of the refrigeration expander.

4. The waste mine energy station integrating power generation, energy storage and combined cooling, heating and power supply according to claim 1, characterized in that: The wind power and photovoltaic power generation equipment is installed on the artificial lake in the subsidence area or at a land location in an abandoned mine.

5. The waste mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply according to claim 1, wherein: The electric energy of the wind power and photovoltaic power generation equipment is divided into three paths. The first path is connected to the power grid, the second path is connected to the motor set, and the third path is connected to the electric heater.

6. The waste mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply according to claim 1, wherein: The underground roadway of the abandoned mine stores energy in a constant pressure mode. The gas transmission pipe is connected to the highest point of the underground roadway of the abandoned mine, and the water transmission pipe is connected to the lowest point of the underground roadway of the abandoned mine.

7. The waste mine energy station integrating power generation, energy storage, and combined cooling, heating, and power supply according to claim 1, characterized in that: When the device is in the combined heat and power supply mode, during the heating season, the inter-stage compression heat is recovered. Part of the hot water drives the heating heat exchanger to supply heat, and the other part of the hot water drives the ORC power generation system to generate electricity for heating. During the non-heating season, all the hot water enters the ORC power generation system to generate electricity. When the device is in the combined cooling and power supply mode, the expansion characteristics of the expansion unit are used for refrigeration to achieve combined cooling and power supply.

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