Integrated energy supply system based on closing down of abandoned resources of a mining area

Abstract

The application relates to a comprehensive energy supply system based on abandoned resources in a closed mine area, and belongs to the technical field of energy optimization operation of a mine area. The application aims at the problem of resource waste caused by abandoned resources in a closed mine area. The comprehensive energy supply system comprises a wind-solar energy generation module for converting wind-solar energy into electric energy and transmitting the electric energy to an electric bus; a solar heat collection module for converting solar energy into heat energy, heating mine water, and outputting electric energy, heat energy and primary circulating water; an energy regeneration module for keeping constant pressure of compressed air generated by the energy regeneration module by using the primary circulating water, simultaneously obtaining electric energy by using the primary circulating water, and obtaining secondary circulating water backflowing to a mine; an energy storage module for storing a heat source and generating electric energy and heat energy by using constant pressure compressed air obtained by the energy storage module; and an energy supply calculation module for calculating output of each energy supply module according to actual demand of electric energy and heat energy, with the lowest cost as the target. The application is used for recycling abandoned resources in a mine area.

Description

Technical Field

[0001] This invention relates to an integrated energy supply system based on abandoned resources in closed mining areas, belonging to the field of energy optimization and operation technology in mining areas. Background Technology

[0002] Under the dual influence of primary sedimentary and diagenetic environments, coal-bearing strata often contain other minerals associated with coal. Transforming and optimizing the regional integrated energy system based on resources derived from the mining process can enhance the energy security margin of the mining area, improve the absorption of renewable energy, increase energy utilization efficiency, and reduce carbon emissions and the cost of purchasing energy from external sources.

[0003] Current research on integrated energy in mining areas focuses on optimizing and modeling the integrated energy system of mining areas based on various derivative resources generated during the operation of coal mines. However, with the closure of technologically backward mines with low productivity and heavy pollution, a large amount of undeveloped space, water resources, and renewable thermal energy have been generated. This not only results in a huge waste of resources but also easily induces geological disasters and environmental pollution.

[0004] Therefore, there is an urgent need to develop and utilize the large amount of abandoned resources in closed mining areas. Summary of the Invention

[0005] To address the resource waste problem caused by abandoned resources in closed mining areas, this invention provides a comprehensive energy supply system based on abandoned resources in closed mining areas.

[0006] The present invention provides an integrated energy supply system based on abandoned resources in closed mining areas, comprising:

[0007] Wind and solar energy generation modules are used to convert wind and solar energy into electrical energy through wind turbines and photovoltaic panels and transmit it to the power bus.

[0008] The solar thermal collector module is used to convert solar energy into thermal energy to heat mine water, and outputs electrical energy, thermal energy and primary circulating water;

[0009] The energy storage module is used to maintain the pressure of compressed air generated by the energy regeneration module using primary circulating water, while simultaneously obtaining electrical energy from the primary circulating water; and obtaining secondary circulating water to return to the mine.

[0010] The energy regeneration module is used to store heat sources and generate electricity by combining the constant-pressure compressed air obtained from the energy storage module, thus obtaining electrical and thermal energy.

[0011] The energy supply calculation module is used to calculate the output of each energy supply module based on the actual demand for electricity and heat, with the goal of minimizing costs, by using wind and solar power generation modules, solar thermal collection modules, energy storage modules, and energy regeneration modules as energy supply modules.

[0012] According to the integrated energy supply system based on abandoned resources in closed mining areas of the present invention, the solar thermal collector module includes a solar collector, an evaporator, a steam turbine, a condenser, a water source heat pump, a condensing heat exchanger, and a water source heat exchanger.

[0013] The water supply pipeline of the solar collector is used to input mine water at the first end and connected to the inlet of the evaporator at the end. The outlet of the evaporator is connected to the inlet of the water source heat pump. The heat energy obtained by the water source heat pump is transferred to the heat bus via the water source heat exchanger. The outlet of the water source heat pump outputs primary circulating water. The water source heat pump is powered by the electric bus. The evaporator outputs steam to the steam turbine. The steam impacts the steam turbine to generate electricity, which is transferred to the electric bus. The steam turbine outputs steam to the condenser. The condenser outputs organic working fluid to the evaporator. The heat energy obtained by the condenser is transferred to the heat bus via the condenser heat exchanger.

[0014] According to the integrated energy supply system based on abandoned resources in closed mining areas of the present invention, the energy storage module includes a mine shaft, a submersible pump, a hydroelectric generator, a shallow mine reservoir, a deep mine compressed air storage tank, and a low-temperature waste heat exchanger.

[0015] Mine water is pumped from the mine to the beginning of the water supply pipeline of the solar collector via a submersible pump. The outlet of the water source heat pump discharges the primary circulating water into a shallow mine reservoir. The outlet branch of the shallow mine reservoir connects to a turbine generator, and the electrical energy output by the turbine generator is transmitted to the power bus. The secondary circulating water output by the turbine generator flows back to the mine. The outlet branch of the shallow mine reservoir connects to the inlet of the deep mine compressed air storage tank via a check valve. The compressed air inlet of the deep mine compressed air storage tank connects to the compressed gas outlet of a low-temperature waste heat exchanger. The outlet of the deep mine compressed air storage tank is connected to the mine via the low-temperature waste heat exchanger and the check valve. The compressed gas inlet of the low-temperature waste heat exchanger is used to input compressed air generated by the energy regeneration module, and the compressed air outlet of the deep mine compressed air storage tank outputs constant pressure compressed air.

[0016] The height difference between shallow mine water storage reservoirs and deep mine compressed air storage reservoirs is at least 1000 meters.

[0017] According to the integrated energy supply system based on abandoned resources in closed mining areas of the present invention, the energy regeneration module includes a primary compressor, a secondary compressor, a primary turbine, a secondary turbine, a high-temperature packed bed thermal storage tank, and a medium-temperature packed bed thermal storage tank.

[0018] The primary compressor obtains high-temperature compressed air via an electrical bus and stores it in a high-temperature packed bed thermal storage tank. The thermal outlet of the high-temperature packed bed thermal storage tank is connected to a thermal bus. Hot air outlet one of the high-temperature packed bed thermal storage tank is connected to the secondary compressor, and hot air outlet two is connected to the secondary turbine. The secondary compressor obtains medium-temperature compressed air via an electrical bus and stores it in a medium-temperature packed bed thermal storage tank. The hot air output from the medium-temperature packed bed thermal storage tank is connected to the compressed air inlet of the deep mine compressed air storage tank via a low-temperature waste heat exchanger, and is also used by the primary turbine to obtain high-temperature compressed air before being stored in the high-temperature packed bed thermal storage tank. The thermal outlet of the medium-temperature packed bed thermal storage tank is connected to the thermal bus. The electrical energy generated by the secondary turbine is transferred to the electrical bus. The constant-pressure compressed air output from the compressed air outlet of the deep mine compressed air storage tank is transferred to the medium-temperature packed bed thermal storage tank.

[0019] According to the integrated energy supply system based on abandoned resources in closed mining areas of the present invention, a solar thermal collector is used in the solar thermal module to convert solar energy into thermal energy to heat the mine water. The heat absorbed by the mine water is expressed as Q. SF :

[0020] Q SF =Q solar -Q loss -Q pipe (1),

[0021] In the formula Q solar The solar energy input to the solar collector, Q loss Q represents the heat loss of the solar collector. pipe Heat loss due to water pipelines;

[0022] The mathematical model for the organic Rankine cycle, which involves heat exchange between heated mine water and organic working fluid, is as follows:

[0023]

[0024] In the formula Q eva c is the energy absorbed by the organic working fluid during the evaporation process as it flows through the evaporator. w m is the specific heat capacity of water. g,w T is the mass flow rate of the mine water flowing through the evaporator. g,w,in T represents the mine water temperature at the evaporator inlet. g,w,out W represents the mine water temperature at the outlet of the evaporator. turb For the power generation of the steam turbine, m f Let Q be the mass flow rate of the organic working fluid, h1 be the inlet enthalpy of the organic working fluid in the turbine, h2 be the outlet enthalpy of the organic working fluid in the turbine, and Q be the mass flow rate of the organic working fluid. con m is the energy released during the condensation process of the working fluid flowing through the condenser. w T is the mass flow rate of condensate in the condenser.w,in T is the inlet temperature of the organic working fluid in the condenser. w,out This refers to the outlet temperature of the organic working fluid in the condenser.

[0025] According to the integrated energy supply system based on abandoned resources in closed mining areas of the present invention, the method for calculating the mine water volumetric flow rate of shallow mine water reservoirs and deep mine compressed air storage tanks is as follows:

[0026]

[0027] In the formula W t u Let t be the volumetric flow rate of mine water discharged from the shallow mine reservoir, and Δt be the time difference between adjacent times, in meters. g1,w The flow rate of mine water, qm ht,t W is the flow rate of water passing through the turbine generator. t d Let W be the volumetric flow rate of mine water discharged from the compressed air storage tank in the deep mine at time t. t in W represents the water flow rate from a shallow mine reservoir into a deep mine compressed air storage tank. t out The flow rate of water flowing from the compressed air storage tank in the deep mine shaft to the mine shaft;

[0028] Hydropower generator output P ht for:

[0029] P ht =η ht ·g·h ht ·qm ht,t (4),

[0030] In the formula h ht where g is the efficiency of the hydroelectric generator, h is the acceleration due to gravity, and g is the acceleration due to gravity. ht The height difference between the shallow mine reservoir and the hydroelectric generator.

[0031] According to the integrated energy supply system based on abandoned resources in closed mining areas of the present invention, the method for establishing thermal storage models for high-temperature filled bed thermal storage and medium-temperature filled bed thermal storage is the same;

[0032] Based on the finite element principle, the high-temperature or medium-temperature packed bed thermal storage tank is divided into n incremental slices of thickness Δz along the height direction. The heat exchange between the hot air and the packing particles in each incremental slice is ΔQ. ex for:

[0033]

[0034] In the formula The volumetric heat transfer coefficient of the packed bed is... The air temperature entering the packed bed thermal storage is T s C represents the temperature of the solid filling particles inside the thermal storage tank. s The average cross-sectional area of ​​the filled bed thermal storage tank;

[0035]

[0036] In the formula, G is the core mass velocity of the hot air, and d a The average radius of the filling particles;

[0037] The thermal storage state model of the filled bed thermal storage tank at time t is as follows:

[0038]

[0039] In the formula Let t be the amount of heat stored in the thermal storage bed when it is filled. This is a compressor state variable, and it is a 0-1 variable. Let t be the amount of compressed heat absorbed by the filled bed thermal storage tank. These are turbine state variables, 0-1 variables; Let t be the heat consumed by heating the air in the filling bed thermal storage tank. Let t be the output heat of the filled bed thermal storage tank. This represents the minimum heat storage capacity of a filled-bed thermal storage tank. This represents the maximum heat storage capacity of the filled bed thermal storage tank.

[0040] According to the integrated energy supply system based on abandoned resources in a closed mining area of ​​the present invention, the power consumption of the primary compressor or the secondary compressor at time t is:

[0041]

[0042] In the formula Let t be the power consumption of the N-stage compressor. γ represents the adiabatic efficiency of an N-class compressor, and γ is the adiabatic index of air. R is the air mass flow rate consumed by the N-stage compressor at time t. g The gas constant is... β is the inlet air temperature of the N-stage compressor. j,N This refers to the compression ratio of an N-stage compressor.

[0043] N-stage compressor outlet air temperature for:

[0044]

[0045] The heat absorbed by high-temperature packed bed thermal storage and medium-temperature packed bed thermal storage is:

[0046]

[0047] In the formula To absorb heat for high-temperature packed bed thermal storage, For the medium-temperature packed bed thermal storage to absorb heat, c a The specific heat capacity of air, This refers to the outlet air temperature of the primary compressor. This refers to the outlet air temperature of the secondary compressor. The air temperature flowing out of the medium-temperature packed bed thermal storage tank during the energy storage stage;

[0048] The heat release of the high-temperature packed bed thermal storage and the medium-temperature packed bed thermal storage is as follows:

[0049]

[0050] In the formula For the heat release of the medium-temperature packed bed thermal storage, For the heat release of high-temperature filled bed thermal storage, Let t be the mass flow rate of air passing through the turbine during time period t. Let be the inlet temperature of the first-stage turbine at time t. For ambient temperature, The inlet temperature of the secondary turbine during time period t is [value]. The outlet temperature of the first-stage turbine during time period t;

[0051] Power generation of N-class turbines for:

[0052]

[0053] In the formula The adiabatic efficiency of an N-class turbine. Let be the mass flow rate of the air passing through the N-stage turbine at time t. Let θ be the inlet temperature of the N-stage turbine at time t. j,N This is the expansion ratio of an N-stage turbine.

[0054] According to the integrated energy supply system based on abandoned resources in closed mining areas of the present invention, the heat exchange model of the low-temperature waste heat exchanger is as follows:

[0055]

[0056] In the formula The mass flow rate of the water at the outlet of the compressed air storage tank in a deep mine tunnel. The water temperature at the outlet of the compressed air storage tank in a deep mine, T st Temperature of compressed air storage tank in deep mine tunnels. This refers to the mass flow rate of compressed air exiting the medium-temperature packed bed thermal storage tank. This refers to the outlet air temperature of the secondary compressor.

[0057] Waste heat from mine water in water source heat pumps for:

[0058]

[0059] In the formula The mass flow rate of the primary circulating water. The primary circulating water supply temperature is... This refers to the return water temperature of the primary circulating water system.

[0060] According to the integrated energy supply system based on abandoned resources in closed mining areas of the present invention, the minimum sum of the following costs is calculated: mine water power generation cost f1, mine water heat generation cost f2, pumped storage cost f3, compressed air energy storage operation cost f4, power grid-heat network operation cost f5, and interactive benefits f6, and an objective function f is constructed:

[0061] f=min{f1+f2+f3+f4+f5+f6}(15),

[0062] Based on the calculation results of the objective function f, determine the output of each energy supply module;

[0063] The cost of pumped storage includes the combined cost of submersible pumps, water source heat pumps, hydroelectric generators, shallow mine reservoirs, and deep mine compressed air storage facilities.

[0064] The beneficial effects of this invention are: This invention utilizes abandoned resources in closed mining areas for renewable energy power generation and multi-form composite energy storage, which can achieve the lowest cost energy supply.

[0065] This invention systematically explores the energy contained in abandoned resources in closed coal mines, achieving comprehensive utilization of geothermal, waste heat, and other energy sources, and storing them to improve overall energy utilization efficiency. Based on this, a new integrated energy supply model can be established, highly integrated and synergistically interacting with combined heat and power (CHP) and combined heat and power storage, mitigating the uncertainties of wind and solar renewable energy sources and promoting the consumption of renewable energy.

[0066] This invention deeply explores the clean energy development potential of abandoned resources in closed mining areas, proposing an innovative architecture for the energy-efficient and interactive conversion of clean heterogeneous energy sources. It can establish an optimization model for integrated energy systems in closed mining areas, including combined heat and power (CHP) and combined heat and power (CHP) storage. This invention cascades and couples low-grade geothermal resources with wind and solar renewable energy, pumped storage, compressed air storage, and water source heat pump technology. Based on the principle of energy cascade utilization, it leverages the complementary advantages of underground space in mines, utilizes the potential difference in geothermal circulating water for energy storage, and employs a multi-level energy recovery method to reduce resource waste. The overall system efficiency can reach 82.71%, and the compressed air energy storage density can reach 2.4709 kWh / m³.3 The electrical-to-electrical efficiency reaches 69.58%. This invention not only helps improve the capacity for renewable energy absorption, but also provides new impetus for the economic and environmental redevelopment of closed mining areas. Attached Figure Description

[0067] Figure 1 This is a schematic diagram of the architecture of the integrated energy supply system based on abandoned resources in closed mining areas as described in this invention; in the figure, h is the depth of the shallow mine water storage reservoir, and H is the height difference between the shallow mine water storage reservoir and the deep mine compressed air storage reservoir.

[0068] Figure 2 This is a specific embodiment of the configuration diagram of the electric-heat network nodes of the integrated energy system in the mining area; in the diagram, numbers 1-6 represent power grid nodes, G1 and G2 represent coal-fired units, PL1-PL3 represent loads, W represents wind power, MIES represents the system of the present invention, and N1-N8 represent heat network nodes;

[0069] Figure 3 This is a schematic diagram of power grid balance in a specific embodiment;

[0070] Figure 4 This is a schematic diagram of the heating power of a specific embodiment;

[0071] Figure 5 This is a schematic diagram of the energy storage status of the pumped storage upper reservoir in a specific embodiment; the upper reservoir is a shallow mine tunnel reservoir;

[0072] Figure 6 This is a schematic diagram of the pressure of a deep mine compressed air storage tank in a specific embodiment; the underground compressed air storage tank in the diagram is a deep mine compressed air storage tank;

[0073] Figure 7 This is a schematic diagram of the gas storage capacity of the deep mine compressed air storage tank in a specific embodiment;

[0074] Figure 8 This is a schematic diagram of the heat storage capacity of the high-temperature packed bed thermal storage tank and the medium-temperature packed bed thermal storage tank in a specific embodiment. Detailed Implementation

[0075] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0076] Specific Implementation Method 1: Combination Figure 1 As shown, the present invention provides an integrated energy supply system based on abandoned resources in closed mining areas, comprising:

[0077] Wind and solar energy generation modules are used to convert wind and solar energy into electrical energy through wind turbines and photovoltaic panels and transmit it to the power bus.

[0078] The solar thermal collector module is used to convert solar energy into thermal energy to heat mine water, and outputs electrical energy, thermal energy and primary circulating water;

[0079] The energy storage module is used to maintain the pressure of compressed air generated by the energy regeneration module using primary circulating water, while simultaneously obtaining electrical energy from the primary circulating water; and obtaining secondary circulating water to return to the mine.

[0080] The energy regeneration module is used to store heat sources and generate electricity by combining the constant-pressure compressed air obtained from the energy storage module, thus obtaining electrical and thermal energy.

[0081] The energy supply calculation module is used to calculate the output of each energy supply module based on the actual demand for electricity and heat, with the goal of minimizing costs, by using wind and solar power generation modules, solar thermal collection modules, energy storage modules, and energy regeneration modules as energy supply modules.

[0082] In practice, idle land in mining subsidence areas can be used to build wind and solar renewable energy power generation units and solar thermal collection units. Wind and solar renewable energy are mainly converted into electricity through wind turbines and photovoltaic panels, while the thermal collection units convert solar energy into heat energy through solar collectors.

[0083] further, Figure 1 The solar thermal collector module includes a solar collector, an evaporator, a steam turbine, a condenser, a water source heat pump, a condensing heat exchanger, and a water source heat exchanger.

[0084] The water supply pipeline of the solar collector is used to input mine water at the first end and connected to the inlet of the evaporator at the end. The outlet of the evaporator is connected to the inlet of the water source heat pump. The heat energy obtained by the water source heat pump is transferred to the heat bus via the water source heat exchanger. The outlet of the water source heat pump outputs primary circulating water. The water source heat pump is powered by the electric bus. The evaporator outputs steam to the steam turbine. The steam impacts the steam turbine to generate electricity, which is transferred to the electric bus. The steam turbine outputs steam to the condenser. The condenser outputs organic working fluid to the evaporator. The heat energy obtained by the condenser is transferred to the heat bus via the condenser heat exchanger.

[0085] Energy storage modules include mine shafts, submersible pumps, hydroelectric generators, shallow mine reservoirs, deep mine compressed air storage tanks, and low-temperature waste heat exchangers.

[0086] Mine water is pumped from the mine to the beginning of the water supply pipeline of the solar collector via a submersible pump. The outlet of the water source heat pump discharges the primary circulating water into a shallow mine reservoir. The outlet branch of the shallow mine reservoir connects to a turbine generator, and the electrical energy output by the turbine generator is transmitted to the power bus. The secondary circulating water output by the turbine generator flows back to the mine. The outlet branch of the shallow mine reservoir connects to the inlet of the deep mine compressed air storage tank via a check valve. The compressed air inlet of the deep mine compressed air storage tank connects to the compressed gas outlet of a low-temperature waste heat exchanger. The outlet of the deep mine compressed air storage tank is connected to the mine via the low-temperature waste heat exchanger and the check valve. The compressed gas inlet of the low-temperature waste heat exchanger is used to input compressed air generated by the energy regeneration module, and the compressed air outlet of the deep mine compressed air storage tank outputs constant pressure compressed air.

[0087] The height difference between shallow mine water storage reservoirs and deep mine compressed air storage reservoirs is at least 1000 meters.

[0088] The main mining depth of the coal mine ranges from 800 to 1000 meters. The geothermal gradient increases by 3°C for every 100 meters of depth. Mine water is stored in the mine and continuously heated by the Earth. Low-enthalpy geothermal resources are a clean energy source. The mine water is used as circulating water to further exploit the potential of low-quality geothermal resources. Medium- and low-temperature, low-grade geothermal resources are pumped to the surface and heated by solar collectors in a solar thermal energy production unit to increase the enthalpy of the geothermal energy, converting it into a high-grade heat source. Geothermal power generation is then achieved through the Rankine cycle.

[0089] The significant location difference between surface or shallow mine shafts and deep mine shafts, combined with the location conditions of deep and shallow mine shafts, means that geothermal water pumped to the surface still retains a certain potential energy for power generation. Before being backfilled underground, this geothermal water can be stored in shallow mine shafts, forming pumped-storage energy storage, achieving multi-form electrical energy storage, and further improving resource utilization. Utilizing deep abandoned mine shafts as compressed air storage chambers, to increase the compressed air storage density, the shallow mine shaft reservoir, the deep mine shaft compressed air storage chamber, and the geothermal reinjection well are connected via check valves to form a circulation system. When the height difference between deep and shallow mine shafts is 800–1000m, the impact of water depth changes in the shallow mine shaft reservoir on the storage chamber pressure can be ignored, forming a water pressure compensated constant-pressure compressed air storage chamber.

[0090] The energy regeneration module includes a primary compressor, a secondary compressor, a primary turbine, a secondary turbine, a high-temperature packed bed thermal storage tank, and a medium-temperature packed bed thermal storage tank.

[0091] The primary compressor obtains high-temperature compressed air via an electrical bus and stores it in a high-temperature packed bed thermal storage tank. The thermal outlet of the high-temperature packed bed thermal storage tank is connected to a thermal bus. Hot air outlet one of the high-temperature packed bed thermal storage tank is connected to the secondary compressor, and hot air outlet two is connected to the secondary turbine. The secondary compressor obtains medium-temperature compressed air via an electrical bus and stores it in a medium-temperature packed bed thermal storage tank. The hot air output from the medium-temperature packed bed thermal storage tank is connected to the compressed air inlet of the deep mine compressed air storage tank via a low-temperature waste heat exchanger, and is also used by the primary turbine to obtain high-temperature compressed air before being stored in the high-temperature packed bed thermal storage tank. The thermal outlet of the medium-temperature packed bed thermal storage tank is connected to the thermal bus. The electrical energy generated by the secondary turbine is transferred to the electrical bus. The constant-pressure compressed air output from the compressed air outlet of the deep mine compressed air storage tank is transferred to the medium-temperature packed bed thermal storage tank.

[0092] Depending on the location distribution, high-temperature and medium-temperature packed bed thermal storage tanks are established in the nearest vertically adjacent mine shafts to the deep mine compressed air storage tanks, using gravel as the filling thermal storage particles. The number of packed bed thermal storage tanks should be consistent with the number of compressors; therefore, two underground packed bed thermal storage tanks, one for high temperature and one for low temperature, are set up corresponding to the two-stage compressors.

[0093] The compressor pressurizes air and stores it in an underground compressed air storage tank. To prevent the high temperature of the compressed air from reducing the energy storage density, the compressed air passes through an underground packed bed thermal storage tank before entering the tank, absorbing the heat carried by the compressed air and lowering its temperature. When the power system is experiencing peak electricity demand, the high-pressure gas in the storage tank undergoes non-combustion heating in the packed bed thermal storage tank before entering the turbine, improving the turbine's power generation capacity.

[0094] In this embodiment, the energy-saving unit mainly consists of a water source heat pump and a heat exchanger. This unit recovers low-grade energy, improving the system's energy conversion efficiency. In the solar thermal collector module, the water at the evaporator outlet still retains some waste heat. The water source heat pump converts this low-grade heat energy into high-enthalpy heat energy, while the heat exchanger recovers the heat dissipation of unsaturated steam from the condenser. Furthermore, during compressed air energy storage, although the heat generated during compressor compression is cooled by the packed bed, the high-pressure air flowing out of the packed bed heat storage still retains some low-grade waste heat. To improve energy utilization, a low-temperature waste heat exchanger is installed at the inlet of the compressed air storage tank. This recovered heat heats the return water flowing from the storage tank to the reinjection well, achieving energy savings.

[0095] In summary, by coupling and integrating geothermal, wind and solar renewable energy power generation with mine energy storage resources, and connecting the power-heat network in the form of a closed energy hub in the mining area, energy can be supplied to users with electricity and heat loads.

[0096] Combination Figure 1As shown, in this embodiment, the signal flow for the geothermal power generation stage is: 1→2→3→4→5→6; the signal flow for the compressed air energy storage stage is: 9→10→11→12→13→14; and the signal flow for the compressed air energy release stage is: 15→16→17→18. Furthermore, shallow mine water storage can provide electricity through hydroelectric power generation. During optimized operation, the output of each distributed unit in the system can be effectively coordinated through economic efficiency optimization objectives, fully utilizing the coupling mechanism between various heterogeneous energy sources to achieve optimal system economy while improving the comprehensive efficiency of multi-energy flow complementarity.

[0097] Furthermore, in the solar thermal collector module, the collected solar energy is transferred to the geothermal fluid in the solar collector loop. The solar thermal collector converts solar energy into heat energy to heat the mine water; the heat absorbed by the mine water is expressed as Q. SF :

[0098] Q SF =Q solar -Q loss -Q pipe (1),

[0099] In the formula Q solar The solar energy input to the solar collector, Q loss Q represents the heat loss of the solar collector. pipe Heat loss due to water pipelines;

[0100] The system employs a parabolic trough solar thermal collector and utilizes the Organic Rankine Cycle (ORC) as the power cycle. The geothermal water flowing out of the mine is heated by solar energy and then directly exchanges heat with the organic working fluid. Compared with the steam Rankine Cycle, the organic working fluid used in the Organic Rankine Cycle has a lower boiling point and is more suitable for low-temperature power generation systems.

[0101] The mathematical model for the organic Rankine cycle, which involves heat exchange between heated mine water and organic working fluid, is as follows:

[0102]

[0103] In the formula Q eva c is the energy absorbed by the organic working fluid during the evaporation process as it flows through the evaporator. w m is the specific heat capacity of water. g,w T is the mass flow rate of the mine water flowing through the evaporator. g,w,in T represents the mine water temperature at the evaporator inlet. g,w,out W represents the mine water temperature at the outlet of the evaporator. turb For the power generation of the steam turbine, m f Let Q be the mass flow rate of the organic working fluid, h1 be the inlet enthalpy of the organic working fluid in the turbine, h2 be the outlet enthalpy of the organic working fluid in the turbine, and Q be the mass flow rate of the organic working fluid. conm is the energy released during the condensation process of the working fluid flowing through the condenser. w T is the mass flow rate of condensate in the condenser. w,in T is the inlet temperature of the organic working fluid in the condenser. w,out This refers to the outlet temperature of the organic working fluid in the condenser.

[0104] The water balance constraints and storage capacity constraints for shallow mine water storage reservoirs and deep mine compressed air storage reservoirs are as follows:

[0105] The calculation method for mine water volumetric flow rate in shallow mine water reservoirs and deep mine compressed air storage facilities is as follows:

[0106]

[0107] In the formula W t u Let t be the volumetric flow rate of mine water discharged from the shallow mine reservoir, and Δt be the time difference between adjacent times, in meters. g1,w The flow rate of mine water, qm ht,t W is the flow rate of water passing through the turbine generator. t d Let W be the volumetric flow rate of mine water discharged from the compressed air storage tank in the deep mine at time t. t in W represents the water flow rate from a shallow mine reservoir into a deep mine compressed air storage tank. t out The flow rate of water flowing from the compressed air storage tank in the deep mine shaft to the mine shaft;

[0108] Pumped storage hydroelectric power in underground mines generates electricity using a hydroelectric generator, with the generator producing a power output P. ht for:

[0109] P ht =η ht ·g·h ht ·qm ht,t (4),

[0110] In the formula h ht where g is the efficiency of the hydroelectric generator, h is the acceleration due to gravity, and g is the acceleration due to gravity. ht The height difference between the shallow mine reservoir and the hydroelectric generator.

[0111] The methods for establishing thermal storage models for high-temperature packed bed thermal storage and medium-temperature packed bed thermal storage are the same;

[0112] Abandoned mine shafts with filled bed thermal storage are well-suited for large-scale compressed air energy storage power plants. A distributed parameter method is used to establish a thermal storage model. Based on the finite element method, the high-temperature or medium-temperature filled bed thermal storage is divided into n incremental slices of thickness Δz along the height direction, and the temperature distribution of each slice is calculated. The heat transfer process between compressed air and the filled bed particles is modeled using a one-dimensional continuous phase-solid phase model.

[0113] The amount of heat exchanged between the hot air and the filling particles in each incremental slice, ΔQ ex for:

[0114]

[0115] In the formula The volumetric heat transfer coefficient of a packed bed depends on the geometry of the packing material, the surface area and volume of the solid packing material, and the airflow characteristics. The air temperature entering the packed bed thermal storage is T s C represents the temperature of the solid filling particles inside the thermal storage tank. s The average cross-sectional area of ​​the filled bed thermal storage tank;

[0116] According to the Contier and Farber formulas, the volumetric heat transfer coefficient during heat exchange between air and packing particles can be expressed as:

[0117]

[0118] In the formula, G is the core mass velocity of the hot air, and d a The average radius of the filling particles (gravel);

[0119] The thermal storage state model of the filled bed thermal storage tank at time t is as follows:

[0120]

[0121] In the formula Let t be the amount of heat stored in the thermal storage bed when it is filled. This is a compressor state variable, and it is a 0-1 variable. Let t be the amount of compressed heat absorbed by the filled bed thermal storage tank. These are turbine state variables, 0-1 variables; Let t be the heat consumed by heating the air in the filling bed thermal storage tank. Let t be the output heat of the filled bed thermal storage tank. This represents the minimum heat storage capacity of a filled-bed thermal storage tank. This represents the maximum heat storage capacity of the filled bed thermal storage tank.

[0122] The power consumption of the first-stage or second-stage compressor at time t is:

[0123]

[0124] In the formula Let t be the power consumption of the N-stage compressor. γ represents the adiabatic efficiency of an N-class compressor, and γ is the adiabatic index of air. R is the air mass flow rate consumed by the N-stage compressor at time t. g The gas constant is β is the inlet air temperature of the N-stage compressor. j,N This refers to the compression ratio of an N-stage compressor.

[0125] N-stage compressor outlet air temperature for:

[0126]

[0127] In compressed air energy storage, high- and low-temperature packed bed thermal storage tanks cool the high-temperature compressed air and store the heat of air compression. The higher-temperature compressed air flows through the packed bed thermal storage tank via contact heat exchange, transferring heat to the packing particles for storage. The heat absorbed by the high-temperature and medium-temperature packed bed thermal storage tanks is as follows:

[0128]

[0129] In the formula To absorb heat for high-temperature packed bed thermal storage, For the medium-temperature packed bed thermal storage to absorb heat, c a The specific heat capacity of air, This refers to the outlet air temperature of the primary compressor. This refers to the outlet air temperature of the second-stage compressor. The air temperature flowing out of the medium-temperature packed bed thermal storage tank during the energy storage stage;

[0130] When compressed air is used for energy storage and release, the stored heat of compression heats the high-pressure air, increasing the turbine's ability to perform work during power generation, and it can also supply heat to the heating network. The heat release of high-temperature packed bed thermal storage and medium-temperature packed bed thermal storage is as follows:

[0131]

[0132] In the formula For the heat release of the medium-temperature packed bed thermal storage, For the heat release of the high-temperature filled bed thermal storage, Let t be the mass flow rate of air passing through the turbine during time period t. The inlet temperature of the first-stage turbine at time t. For ambient temperature, The inlet temperature of the secondary turbine during time period t is [temperature value]. The outlet temperature of the first-stage turbine during time period t;

[0133] Power generation of N-class turbines for:

[0134]

[0135] In the formula The adiabatic efficiency of an N-class turbine. Let be the mass flow rate of the air passing through the N-stage turbine at time t. Let θ be the inlet temperature of the N-stage turbine at time t. j,N This is the expansion ratio of an N-stage turbine.

[0136] In the Rankine cycle, usable heat entering the heating network needs to be exchanged through a heat exchanger. Furthermore, the compressed air after heat exchange in the low-temperature packed bed thermal storage still contains some low-quality waste heat. If this air were to directly enter the gas storage facility, it would not only reduce energy storage density but also waste resources. Therefore, a low-temperature waste heat utilization scheme is proposed.

[0137] The heat transfer model of the low-temperature waste heat exchanger is as follows:

[0138]

[0139] In the formula The mass flow rate of the water at the outlet of the compressed air storage tank in a deep mine tunnel. The water temperature at the outlet of the compressed air storage tank in a deep mine, T st Temperature of compressed air storage tank in deep mine tunnels. This refers to the mass flow rate of compressed air exiting the medium-temperature packed bed thermal storage tank. This refers to the outlet air temperature of the secondary compressor.

[0140] After the geothermal water undergoes heat exchange via the Rankine cycle, it still retains a certain amount of low-grade heat. Before entering the upper reservoir, the residual low-grade heat from the geothermal water can be further absorbed by a water source heat pump to supply heat to the heating network load.

[0141] Waste heat from mine water in water source heat pumps for:

[0142]

[0143] In the formula The mass flow rate of the primary circulating water. The primary circulating water supply temperature is... This refers to the return water temperature of the primary circulating water system.

[0144] The main function of an electric-heat network is to supply energy to users with electric and heat loads, and it must meet the constraints of electric and heat power balance.

[0145] The power bus balance constraint is:

[0146]

[0147] Where Let is the electrical load during time period t; Pjt is the electrical power consumed and stored by each unit in the system during time period t; and Pit is the power generated by each power generation unit in the system during time period t.

[0148] The thermal bus balance constraint is:

[0149]

[0150] In the formula L h,t The heat load for time period t; Q jt Q represents the thermal storage power in the system during time period t; it Let t represent the heat output of each thermal energy production unit in the system during time period t.

[0151] Finally, the minimum sum of the costs of mine water power generation (f1), mine water heat production (f2), pumped storage (f3), compressed air storage operation (f4), power grid-heat network operation (f5), and interactive benefits (f6) is calculated to construct the objective function f:

[0152] f=min{f1+f2+f3+f4+f5+f6}(15),

[0153] Based on the calculation results of the objective function f, determine the output of each energy supply module;

[0154] The cost of pumped storage includes the combined cost of submersible pumps, water source heat pumps, hydroelectric generators, shallow mine reservoirs, and deep mine compressed air storage facilities.

[0155] The energy optimization model in this embodiment includes both continuous and integer variables, and exhibits non-convex and nonlinear characteristics. By performing piecewise linearization on the nonlinear equations and transforming the model into a mixed-integer linear programming problem, the optimal scheduling scheme can be determined using a solver. Specific implementation examples:

[0157] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. The purpose and effects of the present invention will become clearer. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0158] A simulation application of an integrated energy system for a closed mining area is conducted using an IEEE 6-node power grid system and an 8-node heating network system. The closed mining area's integrated energy system acts as a hub, connecting the electricity and heating networks through a second power grid node and a second heating network node. The first and sixth power grid nodes each connect to two coal-fired power units, and a wind farm is located at the second power grid node. The system application structure is as follows: Figure 2 As shown.

[0159] The simulation results of the optimization model for the closed mining area's integrated energy system are as follows: Figures 3-8 As shown.

[0160] Power balance, such as Figure 3 As shown, during the period t=3-6, the user-side power load is low, resulting in a surplus of wind power generation. The compressor of the WPC-CAES (water pressure compensated constant pressure compressed air storage chamber) starts operating, utilizing the surplus wind power to begin energy storage, thereby effectively absorbing the redundant power of wind power generation. During the period t=9-13, the user-side power load climbs to its peak, and the wind power generation is insufficient to meet the high load demand of users. At this time, the WPC-CAES and the Organic Rankine Cycle (ORC) work together with the coal-fired units to participate in peak-shaving power generation to meet the high demand for power, reducing the total output of the coal-fired units by 124.042MW. Similarly, during the period t=18-22, due to the large fluctuations in wind power generation, it is unable to meet the second peak demand of user power load. The turbine, water turbine, and ORC again work together with the coal-fired units to meet the power load demand. The comparison reveals that when wind power is sufficient, the compressor can utilize redundant wind power to achieve effective energy storage; while when wind power is insufficient, the coordinated operation of turbines, water turbines, and coal-fired units not only meets the demand for electricity load but also significantly reduces the output of coal-fired units, thereby reducing carbon emissions.

[0161] Heating power such as Figure 4 As shown. At times such as t=2-4, during the ORC power generation process, the condenser side generates a large amount of waste heat. Simultaneously, the geothermal water flowing out after power generation still carries a certain amount of low-grade heat energy. Therefore, the water source heat pump converts this low-grade heat energy into high-grade heat energy and "transports" it to the heating network to meet the heat load demand. When the heating capacity relying solely on the water source heat pump to "transport" heat energy cannot meet the heat load demand, such as at t=1, 5, and 10, the system will extract heat from the packed bed thermal storage tank, while retaining the heat energy required by the turbine, to supplement the heating gap in the heating network.

[0162] Figure 5This demonstrates the energy storage state of a shallow mine reservoir, whose water volume is closely related to the operating status of the submersible pump and the hydroelectric generator. During the energy storage phase, when the submersible pump operates (consuming electricity), such as at t = 2-4, it draws water from the geothermal layer and delivers it to the shallow mine reservoir, causing an increase in the reservoir's water volume. This increase depends on the power of the submersible pump and is constrained by the upper and lower limits of the reservoir's capacity. During the energy release phase, when the submersible pump and the hydroelectric generator operate simultaneously, if the submersible pump power is greater than the hydroelectric generator power (absolute value), the water volume in the shallow mine reservoir increases; conversely, if the hydroelectric generator power is greater than the submersible pump power (absolute value), the water volume in the shallow mine reservoir decreases, as at t = 1, 5, 10, etc.

[0163] Figure 6 and Figure 7 The changes in pressure and gas storage capacity of the compressed air storage tank in the deep mine tunnel are shown respectively. Figure 6 This indicates that regardless of changes in the operating conditions of the compressor or turbine, the deep mine compressed air storage tank can maintain a stable constant pressure. Figure 7 This reflects the changes in the gas storage capacity of compressed air storage tanks in deep mines. During the energy storage phase, when the compressor is running, air is compressed and injected into the storage tank, causing the gas storage capacity to increase, such as at times t=4-7. During the energy release phase, when the turbine is running, compressed air is released from the storage tank to the turbine, driving it to generate electricity, and the gas storage capacity decreases accordingly, such as at times t=8, 10, etc. The specific increase or decrease depends on the power of the compressor / turbine.

[0164] Changes in the heat storage capacity of a packed bed thermal storage tank are as follows: Figure 8 As shown. During the energy storage phase, when the compressor is running, the heat generated during the compression of air is transferred to the heat transfer material as the air flows through the thermal storage chamber, causing the temperature of the thermal storage chamber to rise. However, at t=4-5, although the compressor is still working, the heat it generates is insufficient to offset the heat supplied by the thermal storage chamber to the heating network, thus the temperature of the thermal storage chamber decreases. During the energy release phase, when the turbine is running, because the turbine requires high-temperature steam to improve power generation efficiency, the compressed air absorbs heat as it passes through the packed bed thermal storage chamber, causing the temperature of the thermal storage chamber to decrease.

[0165] Combination Figures 5 to 8 It can be seen that the system's energy storage, heat storage, and gas storage processes operate synchronously: when the compressor is working, not only is compressed air input into the underground gas storage tank, but the heat generated during compression is also stored in the packed bed heat storage tank. During the energy release phase, when the turbine is running, the heat in the heat storage tank is released, providing high-temperature steam to the turbine, thereby increasing its power generation capacity.

[0166] In summary, with the help of compressed air energy storage and pumped hydro storage, it is possible to balance the intermittency and instability of wind power, improve wind power utilization, and reduce the output of coal-fired units, thereby reducing carbon emissions. At the same time, utilizing ORC (Organic Energy Storage) for electricity and heat generation is environmentally friendly, promotes the cascade utilization of energy, and improves economic efficiency.

[0167] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A comprehensive energy supply system based on abandoned resources in closed mining areas, characterized in that, include: Wind and solar energy generation modules are used to convert wind and solar energy into electrical energy through wind turbines and photovoltaic panels and transmit it to the power bus. The solar thermal collector module is used to convert solar energy into thermal energy to heat mine water, and outputs electrical energy, thermal energy and primary circulating water; The energy storage module is used to maintain the pressure of the compressed air generated by the energy regeneration module using primary circulating water, while simultaneously generating electricity using the primary circulating water. And secondary circulating water is returned to the mine; The energy regeneration module is used to store heat sources and generate electricity by combining the constant-pressure compressed air obtained from the energy storage module, thus obtaining electrical and thermal energy. The energy supply calculation module is used to calculate the output of each energy supply module based on the actual demand for electricity and heat, with the goal of minimizing costs, using wind and solar power generation modules, solar thermal collection modules, energy storage modules, and energy regeneration modules as energy supply modules. The solar thermal collector module includes a solar collector, an evaporator, a steam turbine, a condenser, a water source heat pump, a condensing heat exchanger, and a water source heat exchanger. The water supply pipeline of the solar collector is used to input mine water at the first end and connected to the inlet of the evaporator at the second end. The outlet of the evaporator is connected to the inlet of the water source heat pump. The heat energy obtained by the water source heat pump is transferred to the heat bus via the water source heat exchanger. The outlet of the water source heat pump outputs primary circulating water. The water source heat pump is powered by the electric bus. The evaporator outputs steam to the steam turbine. The steam impacts the steam turbine to generate electricity, which is transferred to the electric bus. The steam turbine outputs steam to the condenser. The condenser outputs organic working fluid to the evaporator. The heat energy obtained by the condenser is transferred to the heat bus via the condenser heat exchanger. Energy storage modules include mine shafts, submersible pumps, hydroelectric generators, shallow mine reservoirs, deep mine compressed air storage tanks, and low-temperature waste heat exchangers. Mine water is pumped from the mine to the beginning of the water supply pipeline of the solar collector via a submersible pump. The outlet of the water source heat pump discharges the primary circulating water into a shallow mine reservoir. The outlet branch of the shallow mine reservoir connects to a turbine generator, and the electrical energy output by the turbine generator is transmitted to the power bus. The secondary circulating water output by the turbine generator flows back to the mine. The outlet branch of the shallow mine reservoir connects to the inlet of the deep mine compressed air storage tank via a check valve. The compressed air inlet of the deep mine compressed air storage tank connects to the compressed gas outlet of a low-temperature waste heat exchanger. The outlet of the deep mine compressed air storage tank is connected to the mine via the low-temperature waste heat exchanger and the check valve. The compressed gas inlet of the low-temperature waste heat exchanger is used to input compressed air generated by the energy regeneration module, and the compressed air outlet of the deep mine compressed air storage tank outputs constant pressure compressed air. The height difference between shallow mine water storage reservoirs and deep mine compressed air storage reservoirs is at least 1000 meters; The energy regeneration module includes a primary compressor, a secondary compressor, a primary turbine, a secondary turbine, a high-temperature packed bed thermal storage tank, and a medium-temperature packed bed thermal storage tank. The primary compressor obtains high-temperature compressed air via an electrical bus and stores it in a high-temperature packed bed thermal storage tank. The thermal outlet of the high-temperature packed bed thermal storage tank is connected to a thermal bus. Hot air outlet one of the high-temperature packed bed thermal storage tank is connected to the secondary compressor, and hot air outlet two is connected to the secondary turbine. The secondary compressor obtains medium-temperature compressed air via an electrical bus and stores it in a medium-temperature packed bed thermal storage tank. The hot air output from the medium-temperature packed bed thermal storage tank is connected to the compressed air inlet of the deep mine compressed air storage tank via a low-temperature waste heat exchanger, and is also used by the primary turbine to obtain high-temperature compressed air before being stored in the high-temperature packed bed thermal storage tank. The thermal outlet of the medium-temperature packed bed thermal storage tank is connected to the thermal bus. The electrical energy generated by the secondary turbine is transferred to the electrical bus. The constant-pressure compressed air output from the compressed air outlet of the deep mine compressed air storage tank is transferred to the medium-temperature packed bed thermal storage tank.

2. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 1, characterized in that, In the solar thermal collector module, solar collectors convert solar energy into thermal energy to heat the mine water. The heat absorbed by the mine water is expressed as... : （1）， In the formula The solar energy input to the solar collector, For the heat loss of solar collectors, Heat loss due to water pipelines; The mathematical model for the organic Rankine cycle, which involves heat exchange between heated mine water and organic working fluid, is as follows: （2）， In the formula This refers to the energy absorbed by the organic working fluid during the evaporation process as it flows through the evaporator. The specific heat capacity of water, The mass flow rate of the mine water flowing through the evaporator. The temperature of the mine water at the inlet of the evaporator. The outlet water temperature of the mine water in the evaporator. For the power generation of the steam turbine, The mass flow rate of the organic working fluid. This is the inlet enthalpy of the organic working fluid in the steam turbine. This is the enthalpy of the organic working fluid outlet of the steam turbine. This refers to the energy released during the condensation process of the working fluid flowing through the condenser. This represents the mass flow rate of condensate in the condenser. This refers to the inlet temperature of the organic working fluid in the condenser. This refers to the outlet temperature of the organic working fluid in the condenser.

3. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 2, characterized in that, The calculation method for mine water volumetric flow rate in shallow mine water reservoirs and deep mine compressed air storage facilities is as follows: （3）， In the formula Let be the volumetric flow rate of mine water discharged from the shallow mine reservoir at time t. The time difference between adjacent moments. Mine water flow rate The flow rate of water passing through the turbine generator. Let t be the volumetric flow rate of mine water discharged from the compressed air storage tank in the deep mine. This refers to the water flow rate from a shallow mine reservoir into a deep mine compressed air storage tank. The flow rate of water flowing from the compressed air storage tank in the deep mine shaft to the mine shaft; Hydropower generator power output for: （4）， In the formula For the efficiency of the hydro-generator, It is the acceleration due to gravity. The height difference between the shallow mine reservoir and the hydroelectric generator.

4. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 3, characterized in that, The methods for establishing thermal storage models for high-temperature packed bed thermal storage and medium-temperature packed bed thermal storage are the same; Based on the finite element principle, the high-temperature or medium-temperature packed bed thermal storage tank is divided into n equal parts along the height direction with a thickness of [missing information]. Incremental slices, the amount of heat exchange between hot air and filling particles in each incremental slice. for: （5）， In the formula The volumetric heat transfer coefficient of the packed bed is... The air temperature entering the packed bed thermal storage chamber, The temperature of the solid filling particles inside the thermal storage tank. The average cross-sectional area of ​​the filled bed thermal storage tank; （6）， In the formula The core mass velocity of hot air. The average radius of the filling particles; The thermal storage state model of the filled bed thermal storage tank at time t is as follows: （7）， In the formula Let t be the amount of heat stored in the thermal storage bed when it is filled. This is a compressor state variable, and it is a 0-1 variable. Let t be the amount of compressed heat absorbed by the filled bed thermal storage tank. These are turbine state variables, 0-1 variables; Let t be the heat consumed by heating the air in the filling bed thermal storage tank. Let t be the output heat of the filled bed thermal storage tank. This represents the minimum heat storage capacity of a filled-bed thermal storage tank. This represents the maximum heat storage capacity of the filled bed thermal storage tank.

5. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 4, characterized in that, The power consumption of the first-stage or second-stage compressor at time t is: （8）， In the formula Let t be the power consumption of the N-stage compressor. For N-class compressor adiabatic efficiency, It is the adiabatic index of air. Let be the air mass flow rate consumed by the N-stage compressor at time t. The gas constant is... This refers to the inlet air temperature of the N-stage compressor. This refers to the compression ratio of an N-stage compressor. N-stage compressor outlet air temperature for: （9）； The heat absorbed by high-temperature packed bed thermal storage and medium-temperature packed bed thermal storage is: （10）， In the formula To absorb heat for high-temperature packed bed thermal storage, For the absorption of heat in the medium-temperature packed bed thermal storage, The specific heat capacity of air, This refers to the outlet air temperature of the primary compressor. This refers to the outlet air temperature of the second-stage compressor. The air temperature flowing out of the medium-temperature packed bed thermal storage tank during the energy storage stage; The heat release of the high-temperature packed bed thermal storage and the medium-temperature packed bed thermal storage is as follows: （11）， In the formula For the heat release of the medium-temperature packed bed thermal storage, For the heat release of the high-temperature filled bed thermal storage, Let t be the mass flow rate of air passing through the turbine during time period t. The inlet temperature of the first-stage turbine at time t. For ambient temperature, The inlet temperature of the secondary turbine during time period t is [value]. The outlet temperature of the first-stage turbine during time period t; Power generation of N-class turbines for: （12）， In the formula The adiabatic efficiency of an N-class turbine. Let be the mass flow rate of the air passing through the N-stage turbine at time t. Let be the inlet temperature of the N-stage turbine at time t. This is the expansion ratio of an N-stage turbine.

6. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 5, characterized in that, The heat transfer model of the low-temperature waste heat exchanger is as follows: （13）， In the formula The mass flow rate of the water at the outlet of the compressed air storage tank in a deep mine tunnel. The water temperature at the outlet of the compressed air storage tank in a deep mine. Temperature of compressed air storage tank in deep mine tunnels. This refers to the mass flow rate of compressed air exiting the medium-temperature packed bed thermal storage tank. This refers to the outlet air temperature of the secondary compressor. The waste heat capacity Hg i,t of the mine water in the water source heat pump is: （14）， In the formula The mass flow rate of the primary circulating water. The primary circulating water supply temperature is... This refers to the return water temperature of the primary circulating water system.

7. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 6, characterized in that, Calculate the minimum sum of the following costs: mine water power generation cost f1, mine water heat generation cost f2, pumped storage cost f3, compressed air energy storage operation cost f4, power grid-heat network operation cost f5, and interactive benefits f6, and construct an objective function. : （15）， According to the objective function The calculation results are used to determine the output of each energy supply module; The cost of pumped storage includes the combined cost of submersible pumps, water source heat pumps, hydroelectric generators, shallow mine reservoirs, and deep mine compressed air storage facilities.

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