Comprehensive energy supply system based on closing of abandoned resources in mining area

Abstract

The invention discloses a comprehensive energy supply system based on closing of mining area abandoned resources, and belongs to the technical field of mining area energy optimization operation. The method aims at solving the problem of resource waste existing in abandoned resources of closed mining areas. The wind-light energy power generation module is used for converting wind-light energy into electric energy and transmitting the electric energy to an electric bus; the solar heat collection module is used for heating mine water after converting solar energy into heat energy and outputting electric energy, heat energy and primary circulating water; the compressed air generated by the energy regeneration module is kept at constant pressure by utilizing the primary circulating water, and meanwhile, electric energy is obtained by utilizing the primary circulating water; secondary circulating water is obtained and flows back to the energy storage module of the mine; the energy regeneration module is used for storing the heat source and generating electricity by combining the constant-pressure compressed air obtained by the energy storage module so as to obtain electric energy and heat energy; and the energy supply calculation module calculates the output quantity of each energy supply module according to the actual demand quantity of the electric energy and the heat energy by taking the lowest cost as a target. The method is used for recycling abandoned resources in the mining area.

Description

Technical Field

[0001] The invention relates to a comprehensive energy supply system based on abandoned resources in closed mining areas, and belongs to the technical field of energy optimization operation in mining areas. Background Art

[0002] Under the dual influence of primary sedimentary and diagenetic environments, other minerals often co-occur in coal-bearing strata during coal mining. Transforming and optimizing mining area energy systems into integrated regional energy systems based on resources derived from mining can enhance mining area energy safety margins, improve renewable energy absorption, increase energy efficiency, and reduce carbon emissions and the cost of purchasing external energy.

[0003] Existing research on integrated energy in mining areas focuses on optimizing and modeling integrated energy systems within operating coal mines based on the diverse resources derived from coal mining. However, the closure of low-capacity, high-pollution, and technologically backward mines has resulted in a significant amount of untapped space, water resources, and renewable thermal energy. This not only results in significant resource waste but also contributes to geological disasters and environmental pollution.

[0004] Therefore, a large amount of abandoned resources in closed mining areas urgently need to be developed and utilized. Summary of the Invention

[0005] In order to solve the problem of resource waste caused by abandoned resources in closed mining areas, the present invention provides a comprehensive energy supply system based on the abandoned resources in closed mining areas.

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

[0007] Wind and solar energy power generation module, used to convert wind and solar energy into electrical energy through wind turbines and photovoltaic panels and transmit it to the electric bus;

[0008] Solar thermal collection module, used to convert solar energy into thermal energy to heat mine water, outputting electricity, thermal energy and primary circulating water;

[0009] The energy storage module is used to use the primary circulating water to maintain a constant pressure of the compressed air generated by the energy regeneration module, while also using the primary circulating water to generate electricity; and to obtain secondary circulating water to flow back 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 by the energy storage module to obtain electrical energy and thermal energy;

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

[0012] According to the comprehensive energy supply system based on abandoned resources in closed mining areas of the present invention, the solar thermal collection module includes a solar thermal 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 head end of the water supply pipeline of the solar collector is used to input mine water, and the end is connected to the water inlet of the evaporator. The water outlet of the evaporator is connected to the water inlet of the water source heat pump. The heat energy obtained by the water source heat pump is transferred to the heat bus through the water source heat exchanger, and the water outlet of the water source heat pump outputs primary circulating water; the water source heat pump is provided with working power by the electric bus; the evaporator outputs steam to the steam turbine, and the steam impacts the steam turbine to generate electricity and transmit it to the electric bus; the steam turbine outputs steam to the condenser, and the condenser outputs organic working fluid to the evaporator; the heat energy obtained by the condenser is transferred to the heat bus through the condensing heat exchanger.

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

[0015] The mine water in the mine is input to the head end of the water supply pipeline of the solar collector through a submersible pump, and the outlet of the water source heat pump discharges the primary circulating water into the shallow mine water reservoir. The outlet branch 1 of the shallow mine water reservoir is connected to the hydro-generator, and the electric energy output by the hydro-generator is transmitted to the electric bus, and the secondary circulating water output by the hydro-generator flows back to the mine; the outlet branch 2 of the shallow mine water reservoir is connected to the water inlet of the deep mine compressed air storage reservoir through a check valve; the compressed air inlet of the deep mine compressed air storage reservoir is connected to the compressed gas outlet of the low-temperature waste heat exchanger, and the outlet of the deep mine compressed air storage reservoir is connected to the mine through 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 the compressed air generated by the energy regeneration module, and the compressed air outlet of the deep mine compressed air storage reservoir outputs constant pressure compressed air;

[0016] The height difference between the shallow mine water reservoir and the deep mine compressed air storage is at least 1,000 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 heat storage reservoir and a medium-temperature packed bed heat storage reservoir.

[0018] The first-stage compressor obtains high-temperature compressed air through the electric busbar to provide working power, and stores it in the high-temperature packed bed heat storage reservoir. The heat energy outlet of the high-temperature packed bed heat storage reservoir is connected to the thermal busbar. The hot air outlet one of the high-temperature packed bed heat storage reservoir is connected to the second-stage compressor, and the hot air outlet two is connected to the second-stage turbine. The second-stage compressor obtains medium-temperature compressed air through the electric busbar to provide working power, and stores it in the medium-temperature packed bed heat storage reservoir. The hot air output from the medium-temperature packed bed heat storage reservoir is connected to the compressed air inlet of the deep mine compressed air storage reservoir through the low-temperature waste heat exchanger on the one hand, and the high-temperature compressed air is obtained through the first-stage turbine on the other hand and then stored in the high-temperature packed bed heat storage reservoir. The heat energy outlet of the medium-temperature packed bed heat storage reservoir is connected to the thermal busbar; the electric energy generated by the second-stage turbine is transmitted to the electric busbar; the constant-pressure compressed air output from the compressed air outlet of the deep mine compressed air storage reservoir is transmitted to the medium-temperature packed bed heat storage reservoir.

[0019] According to the integrated energy supply system based on abandoned resources in closed mining areas of the present invention, in the solar thermal collection module, a solar thermal collector is used 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] Where Q solar The solar energy input to the solar collector, Q loss is the heat loss of the solar collector, Q pipe Heat loss in the water pipeline;

[0022] The mathematical model of the organic Rankine cycle for heat exchange between heated mine water and organic working fluid is:

[0023]

[0024] Where Q eva is the energy absorbed by the organic working medium during the evaporation process, c w is the specific heat capacity of water, m g,w is the mass flow rate of mine water flowing through the evaporator, T g,w,in is the mine water temperature at the evaporator inlet, T g,w,out is the mine water temperature at the outlet of the evaporator, W turb is the power generation of the steam turbine, m f is the mass flow rate of the organic working fluid, h1 is the inlet enthalpy of the organic working fluid of the steam turbine, h2 is the outlet enthalpy of the organic working fluid of the steam turbine, Q con The energy released by the working fluid during the condensation process of the condenser, m w is the mass flow rate of condensed water in the condenser, Tw,in is the organic working medium inlet temperature of the condenser, T w,out is 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 mines of the present invention, the volume flow rate of mine water in shallow mine water reservoirs and deep mine compressed air storage reservoirs is calculated as follows:

[0026]

[0027] Where W t u is the volume flow of mine water discharged from the shallow mine reservoir at time t, Δt is the time difference between adjacent moments, m g1,w is the mine water flow rate, qm ht,t is the water flow through the turbine generator, W t d is the volume flow rate of mine water discharged from the deep mine compressed air storage at time t, W t in is the water flow from the shallow mine water reservoir to the deep mine compressed air storage, W t out It is the water flow rate flowing out of the deep mine compressed air storage to the mine;

[0028] Hydrogenerator power generation P ht for:

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

[0030] Where h ht is the efficiency of the turbine generator, g is the acceleration of gravity, h is ht It is the height difference between the shallow mine water reservoir and the hydro-generator.

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

[0032] According to the finite element principle, the high-temperature packed bed heat storage reservoir or the medium-temperature packed bed heat storage reservoir is divided into n increment slices with a thickness of Δz along the height direction. The heat exchange amount ΔQ between the hot air and the filling particles in each increment slice is ex for:

[0033]

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

[0035]

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

[0037] The heat storage state model of the packed bed heat storage at time t is:

[0038]

[0039] In the formula is the heat storage capacity of the filled bed thermal storage at time t, is the compressor state variable, which is a 0-1 variable; is the compression heat absorbed by the packed bed thermal storage reservoir at time t, is the turbine state variable, a 0-1 variable; is the heat consumed by the filled bed thermal storage to heat the air at time t, is the output heat of the filled bed thermal storage at time t, is the minimum heat storage capacity of the packed bed thermal storage tank, It is the maximum heat storage capacity of the packed bed thermal storage tank.

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

[0041]

[0042] In the formula is the power consumption of the N-stage compressor at time t, is the adiabatic efficiency of the N-stage compressor, γ is the adiabatic index of air, is the air mass flow consumed by the N-stage compressor at time t, R g is the gas constant, is the inlet air temperature of the N-stage compressor, β j,N is the compression ratio of the N-stage compressor;

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

[0044]

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

[0046]

[0047] In the formula Absorb heat for high temperature packed bed thermal storage, The medium temperature packed bed thermal storage absorbs heat, c a is the specific heat capacity of air, is the first-stage compressor outlet air temperature, is the secondary compressor outlet air temperature, is the temperature of the air flowing out of the medium-temperature packed bed thermal storage reservoir during the energy storage phase;

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

[0049]

[0050] In the formula is the heat release of the medium-temperature packed bed thermal storage tank, is the heat released by the high-temperature packed bed heat storage tank, is the air mass flow rate passing through the turbine during period t, is the inlet temperature of the first-stage turbine at time t, is the ambient temperature, is the inlet temperature of the two-stage turbine at time t, is the outlet temperature of the first-stage turbine at time t;

[0051] Power generation capacity of N-stage turbine for:

[0052]

[0053] In the formula is the adiabatic efficiency of the N-stage turbine, is the air mass flow rate flowing through the N-stage turbine at time t, is the inlet temperature of the N-stage turbine at time t, θ j,N is the expansion ratio of the N-stage turbine.

[0054] According to the comprehensive 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:

[0055]

[0056] In the formula is the mass flow rate of water at the outlet of the deep mine compressed air storage, is the water temperature at the outlet of the deep mine compressed air storage, T st is the temperature of the deep mine compressed air storage, is the mass flow rate of compressed air flowing out of the medium-temperature packed bed thermal storage reservoir, is the secondary compressor outlet air temperature;

[0057] Waste heat of mine water from water source heat pump for:

[0058]

[0059] In the formula is the mass flow rate of the primary circulating water, is the primary circulating water supply temperature, It is the return water temperature of the first-stage circulating water.

[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 mine water power generation cost f1, the mine water heat generation cost f2, the pumped storage cost f3, the compressed air energy storage operating cost f4, the power grid-heat network operating cost f5 and the interaction benefit f6 is calculated to construct the objective function f:

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

[0062] According to the calculation results of the objective function f, the output of each energy supply module is determined;

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

[0064] Beneficial effects of the present invention: The present invention utilizes abandoned resources in closed mining areas to generate renewable energy and multi-form composite energy storage, thereby achieving the lowest cost energy supply.

[0065] This system deeply taps into the energy contained in abandoned resources in closed coal mines, enabling the comprehensive utilization of geothermal energy, waste heat, and other energy sources, as well as energy storage, thereby improving overall energy utilization efficiency. This system can be used to establish a new form of integrated energy supply that integrates heat-power and heat-power storage, mitigating the uncertain impact of wind and solar renewable energy and promoting renewable energy consumption.

[0066] The present invention deeply explores the clean energy development potential contained in the abandoned resources of closed mining areas, proposes an innovative architecture for energy-saving and efficient interactive conversion of clean heterogeneous energy, and can establish an optimization model for the comprehensive energy system of closed mining areas with combined heat and power supply and combined heat and power storage. The present invention cascade-couples low-grade geothermal resources with wind and solar renewable energy, pumped storage, compressed air energy storage, and water source heat pump technology. Based on the principle of energy cascade utilization, it takes advantage of the complementary advantages of underground space in mines, mobilizes the potential drop storage capacity of geothermal circulating water, and adopts a multi-level energy recovery method to reduce resource waste. The overall system efficiency can reach 82.71%; the compressed air energy storage density can reach 2.4709kWh / m3 The power-to-power efficiency reaches 69.58%. This invention not only helps to improve the capacity to absorb renewable energy, but also provides new impetus for the economic and environmental redevelopment of closed mining areas. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0068] Figure 2 1 is a diagram of the node configuration of the electric-heating network of the closed mining area integrated energy system in a specific embodiment; in the figure, numbers 1-6 represent 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 is a schematic diagram of power balance of a power grid according to a specific embodiment;

[0070] Figure 4 2. It is a schematic diagram of heating power of a specific embodiment;

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

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

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

[0074] Figure 8 It is a schematic diagram of the heat storage capacity of the high-temperature packed bed heat storage reservoir and the medium-temperature packed bed heat storage reservoir in a specific embodiment. DETAILED DESCRIPTION

[0075] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0076] Specific implementation method 1. Combination Figure 1 As shown, the present invention provides a comprehensive energy supply system based on abandoned resources in closed mining areas, comprising:

[0077] Wind and solar energy power generation module, used to convert wind and solar energy into electrical energy through wind turbines and photovoltaic panels and transmit it to the electric bus;

[0078] Solar thermal collection module, used to convert solar energy into thermal energy to heat mine water, outputting electricity, thermal energy and primary circulating water;

[0079] The energy storage module is used to use the primary circulating water to maintain a constant pressure of the compressed air generated by the energy regeneration module, while also using the primary circulating water to generate electricity; and to obtain secondary circulating water to flow back 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 by the energy storage module to obtain electrical energy and thermal energy;

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

[0082] In specific implementation, idle land in the mining subsidence area can be used to establish wind and solar renewable energy power generation units and solar thermal collection units. Wind and solar renewable energy are mainly converted into electrical energy through wind turbines and photovoltaic panels, and the thermal collection unit converts solar energy into thermal energy through solar collectors.

[0083] further, Figure 1 The solar thermal collection module includes a solar thermal 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 head end of the water supply pipeline of the solar collector is used to input mine water, and the end is connected to the water inlet of the evaporator. The water outlet of the evaporator is connected to the water inlet of the water source heat pump. The heat energy obtained by the water source heat pump is transferred to the heat bus through the water source heat exchanger, and the water outlet of the water source heat pump outputs primary circulating water; the water source heat pump is provided with working power by the electric bus; the evaporator outputs steam to the steam turbine, and the steam impacts the steam turbine to generate electricity and transmit it to the electric bus; the steam turbine outputs steam to the condenser, and the condenser outputs organic working fluid to the evaporator; the heat energy obtained by the condenser is transferred to the heat bus through the condensing heat exchanger.

[0085] The energy storage module includes a mine, a submersible pump, a hydro-generator, a shallow mine water reservoir, a deep mine compressed air storage reservoir and a low-temperature waste heat exchanger.

[0086] The mine water in the mine is input to the head end of the water supply pipeline of the solar collector through a submersible pump, and the outlet of the water source heat pump discharges the primary circulating water into the shallow mine water reservoir. The outlet branch 1 of the shallow mine water reservoir is connected to the hydro-generator, and the electric energy output by the hydro-generator is transmitted to the electric bus, and the secondary circulating water output by the hydro-generator flows back to the mine; the outlet branch 2 of the shallow mine water reservoir is connected to the water inlet of the deep mine compressed air storage reservoir through a check valve; the compressed air inlet of the deep mine compressed air storage reservoir is connected to the compressed gas outlet of the low-temperature waste heat exchanger, and the outlet of the deep mine compressed air storage reservoir is connected to the mine through 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 the compressed air generated by the energy regeneration module, and the compressed air outlet of the deep mine compressed air storage reservoir outputs constant pressure compressed air;

[0087] The height difference between the shallow mine water reservoir and the deep mine compressed air storage is at least 1,000 meters.

[0088] The main mining depth of the coal mine ranges from 800 to 1000 meters, with a geothermal gradient of 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. Using mine water as circulating water, the potential of low-quality geothermal resources is deeply explored. Medium-low-temperature, low-grade geothermal resources are pumped to the surface. Solar collectors in the solar thermal energy production unit heat the geothermal energy to increase its enthalpy, converting it into a high-grade heat source. This generates geothermal power through the Rankine cycle.

[0089] Surface or shallow mines and deep mines have a significant location difference. Considering the location conditions of deep and shallow mines, geothermal water still has a certain potential energy capacity to generate power after being pumped to the surface for power generation. This water can be stored in shallow mines before being backfilled underground, forming pumped-storage energy storage, achieving multi-form electrical energy storage and further improving resource utilization. Deep abandoned mines are used as compressed air storage chambers. To increase the compressed air storage density, the shallow mine reservoir, the deep mine compressed air storage, and the geothermal recharge mine are connected through a check valve to form a circulation system. When the height difference between the deep and shallow mines is 800 to 1000 meters, the impact of the shallow mine reservoir's water depth on the storage pressure can be ignored, forming a water pressure-compensated constant-pressure compressed air storage.

[0090] The energy regeneration module includes a first-stage compressor, a second-stage compressor, a first-stage turbine, a second-stage turbine, a high-temperature packed bed heat storage tank and a medium-temperature packed bed heat storage tank.

[0091] The first-stage compressor obtains high-temperature compressed air through the electric busbar to provide working power, and stores it in the high-temperature packed bed heat storage reservoir. The heat energy outlet of the high-temperature packed bed heat storage reservoir is connected to the thermal busbar. The hot air outlet one of the high-temperature packed bed heat storage reservoir is connected to the second-stage compressor, and the hot air outlet two is connected to the second-stage turbine. The second-stage compressor obtains medium-temperature compressed air through the electric busbar to provide working power, and stores it in the medium-temperature packed bed heat storage reservoir. The hot air output from the medium-temperature packed bed heat storage reservoir is connected to the compressed air inlet of the deep mine compressed air storage reservoir through the low-temperature waste heat exchanger on the one hand, and the high-temperature compressed air is obtained through the first-stage turbine on the other hand and then stored in the high-temperature packed bed heat storage reservoir. The heat energy outlet of the medium-temperature packed bed heat storage reservoir is connected to the thermal busbar; the electric energy generated by the second-stage turbine is transmitted to the electric busbar; the constant-pressure compressed air output from the compressed air outlet of the deep mine compressed air storage reservoir is transmitted to the medium-temperature packed bed heat storage reservoir.

[0092] Based on the distribution of locations, high-temperature and medium-temperature packed-bed thermal storage are constructed in the nearest vertically adjacent mines within the deep mine compressed air storage. Gravel is used as the thermal storage granules. The number of packed-bed thermal storage silos should match the number of compressors. Therefore, two underground packed-bed thermal storage silos, high and low temperature, are installed to correspond to the two-stage compressors.

[0093] The compressor pressurizes and stores air in an underground compressed air storage facility. To prevent the high compressed air temperature from reducing the storage's energy density, the compressed air passes through an underground packed bed thermal reservoir, absorbing heat from the compressed air before entering the facility, thereby lowering the compressed air's temperature. During peak power demand, the packed bed thermal reservoir heats the high-pressure air in the storage facility before it enters the turbine, enhancing the compressed air's turbine power generation capacity.

[0094] In this embodiment, the energy-saving unit is mainly composed of a water source heat pump and a heat exchanger. Low-grade energy is recovered through the energy-saving unit to improve the energy conversion efficiency of the system. In the solar thermal collection module, the water at the evaporator outlet still has a certain amount of waste heat. The water source heat pump is used to convert the low-grade thermal energy into high-enthalpy thermal energy. At the same time, the heat dissipation of the unsaturated steam of the working fluid in the condenser is recovered through the heat exchanger. In addition, during the compressed air energy storage process, although the heat generated by the compressor during compression is cooled by the packed bed, a certain amount of low-quality waste heat resources are still retained in the high-pressure air flowing out of the packed bed heat storage reservoir. To improve energy utilization, a low-temperature waste heat exchanger is installed at the inlet of the compressed air storage reservoir. The recovered heat is used to heat the return water flowing from the storage reservoir to the re-injection well, thereby achieving the purpose of energy conservation.

[0095] In summary, coupling and integrating geothermal, wind and solar renewable energy power generation with mine energy storage resources, and connecting the electricity and heat network in the form of a closed mine energy hub, can provide energy for electricity and heat load users.

[0096] Combine Figure 1As shown, in this implementation, the signal flow during the geothermal power generation phase is: 1→2→3→4→5→6; the signal flow during the compressed air energy storage phase is: 9→10→11→12→13→14; and the signal flow during the compressed air energy release phase is: 15→16→17→18. Furthermore, shallow mine water storage can generate electricity through turbines. During optimized operation, the output of each distributed unit in the system can be effectively coordinated through economic efficiency optimization, fully leveraging the coupling mechanism between multiple heterogeneous energy sources to achieve system economic optimization while improving the overall efficiency of multiple energy flows.

[0097] Furthermore, in the solar thermal module, the collected solar energy is transferred to the geothermal fluid in the solar thermal collector circuit. The solar thermal collector is used to convert solar energy into thermal 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] Where Q solar The solar energy input to the solar collector, Q loss is the heat loss of the solar collector, Q pipe Heat loss in the water pipeline;

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

[0101] The mathematical model of the organic Rankine cycle for heat exchange between heated mine water and organic working fluid is:

[0102]

[0103] Where Q eva is the energy absorbed by the organic working medium during the evaporation process, c w is the specific heat capacity of water, m g,w is the mass flow rate of mine water flowing through the evaporator, T g,w,in is the mine water temperature at the evaporator inlet, T g,w,out is the mine water temperature at the outlet of the evaporator, W turb is the power generation of the steam turbine, m f is the mass flow rate of the organic working fluid, h1 is the inlet enthalpy of the organic working fluid of the steam turbine, h2 is the outlet enthalpy of the organic working fluid of the steam turbine, Q conThe energy released by the working fluid during the condensation process of the condenser, m w is the mass flow rate of condensed water in the condenser, T w,in is the organic working medium inlet temperature of the condenser, T w,out is the outlet temperature of the organic working fluid in the condenser.

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

[0105] The calculation method for the volume flow of mine water in shallow mine water storage reservoirs and deep mine compressed air storage reservoirs is:

[0106]

[0107] Where W t u is the volume flow of mine water discharged from the shallow mine reservoir at time t, Δt is the time difference between adjacent moments, m g1,w is the mine water flow rate, qm ht,t is the water flow through the turbine generator, W t d is the volume flow rate of mine water discharged from the deep mine compressed air storage at time t, W t in is the water flow from the shallow mine water reservoir to the deep mine compressed air storage, W t out It is the water flow rate flowing out of the deep mine compressed air storage to the mine;

[0108] The underground mine pumped storage is used to generate electricity by the turbine generator, and the turbine generator power generation power P ht for:

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

[0110] Where h ht is the efficiency of the turbine generator, g is the acceleration of gravity, h is ht It is the height difference between the shallow mine water reservoir and the hydro-generator.

[0111] The method of establishing the thermal storage model for the high-temperature packed bed thermal storage and the medium-temperature packed bed thermal storage is the same;

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

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

[0114]

[0115] In the formula is the volumetric heat transfer coefficient of the packed bed, which depends on the geometric shape of the packing, the surface area and volume of the solid packing, and the flow characteristics of the air; is the air temperature entering the packed bed thermal storage tank, T s is the temperature of the solid filling particles in the thermal storage, C s is the average cross-sectional area of ​​the packed bed thermal storage;

[0116] According to the Contier and Farber formula, the volume heat transfer coefficient when heat exchange occurs between air and filling particles can be expressed as:

[0117]

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

[0119] The heat storage state model of the packed bed heat storage at time t is:

[0120]

[0121] In the formula is the heat storage capacity of the filled bed thermal storage at time t, is the compressor state variable, which is a 0-1 variable; is the compression heat absorbed by the packed bed thermal storage reservoir at time t, is the turbine state variable, a 0-1 variable; is the heat consumed by the filled bed thermal storage to heat the air at time t, is the output heat of the filled bed thermal storage at time t, is the minimum heat storage capacity of the packed bed thermal storage tank, It is the maximum heat storage capacity of the packed bed thermal storage tank.

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

[0123]

[0124] In the formula is the power consumption of the N-stage compressor at time t, is the adiabatic efficiency of the N-stage compressor, γ is the adiabatic index of air, is the air mass flow consumed by the N-stage compressor at time t, R g is the gas constant, is the inlet air temperature of the N-stage compressor, β j,N is the compression ratio of the N-stage compressor;

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

[0126]

[0127] When compressed air is used for energy storage, the high and low temperature packed bed thermal storage tanks cool the high temperature compressed air and store the compressed heat of the air. The higher temperature compressed air flows through the packed bed thermal storage tank through contact heat exchange, transferring the heat to the packed particle thermal storage tank. The high temperature packed bed thermal storage tank and the medium temperature packed bed thermal storage tank absorb heat as follows:

[0128]

[0129] In the formula Absorb heat for high temperature packed bed thermal storage, The medium temperature packed bed thermal storage absorbs heat, c a is the specific heat capacity of air, is the first-stage compressor outlet air temperature, is the secondary compressor outlet air temperature, is the temperature of the air flowing out of the medium-temperature packed bed thermal storage reservoir during the energy storage phase;

[0130] When compressed air energy storage releases energy, the stored compression heat heats the high-pressure air to improve the turbine power generation process and can also provide heat for the heat network load. The heat release capacity of the high-temperature packed bed heat storage and the medium-temperature packed bed heat storage is:

[0131]

[0132] In the formula is the heat release of the medium-temperature packed bed thermal storage tank, is the heat released by the high-temperature packed bed heat storage tank, is the air mass flow rate passing through the turbine during period t, is the inlet temperature of the first-stage turbine at time t, is the ambient temperature, is the inlet temperature of the two-stage turbine at time t, is the outlet temperature of the first-stage turbine at time t;

[0133] Power generation capacity of N-stage turbine for:

[0134]

[0135] In the formula is the adiabatic efficiency of the N-stage turbine, is the air mass flow rate flowing through the N-stage turbine at time t, is the inlet temperature of the N-stage turbine at time t, θ j,N is the expansion ratio of the N-stage turbine.

[0136] The usable heat from the Rankine cycle needs to be transferred to the heat network through a heat exchanger. Furthermore, the compressed air after heat exchange in the low-temperature packed bed heat storage still contains some low-quality waste heat. If this air were to enter the gas storage directly, it would not only reduce the energy storage density but also result in a waste of resources. Therefore, a low-temperature waste heat utilization solution has been proposed.

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

[0138]

[0139] In the formula is the mass flow rate of water at the outlet of the deep mine compressed air storage, is the water temperature at the outlet of the deep mine compressed air storage, T st is the temperature of the deep mine compressed air storage, is the mass flow rate of compressed air flowing out of the medium-temperature packed bed thermal storage reservoir, is the secondary compressor outlet air temperature;

[0140] After the geothermal water has undergone Rankine cycle heat exchange, it still has a certain amount of low-grade heat. Before entering the upper reservoir, the water source heat pump can be used to absorb the remaining low-grade heat of the geothermal water to provide heat for the heating network load.

[0141] Waste heat of mine water from water source heat pump for:

[0142]

[0143] In the formula is the mass flow rate of the primary circulating water, is the primary circulating water supply temperature, It is the return water temperature of the first-stage circulating water.

[0144] The main function of the electricity-heat network is to provide energy to electricity and heat load users, and it must meet the electricity and heat power balance constraints.

[0145] The power bus balance constraint is:

[0146]

[0147] Where Let is the electric load in period t; Pjt is the electric power consumed and stored by each unit in the system in period t; Pit is the power generated by each electric energy production unit in the system in period t.

[0148] The thermal bus balance constraint is:

[0149]

[0150] Where L h,t is the heat load during period t; Q jt is the heat storage power in the system during period t; Q it is the heat production power of each heat energy production unit in the system during period t.

[0151] Finally, the minimum sum of the 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 interaction benefit f6 is calculated to construct the objective function f:

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

[0153] According to the calculation results of the objective function f, the output of each energy supply module is determined;

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

[0155] The energy optimization model in this implementation contains both continuous and integer variables and exhibits non-convex, nonlinear characteristics. By piecewise linearizing the nonlinear equations and converting the model into a mixed-integer linear programming problem, the optimal scheduling solution can be determined using a solver. Specific embodiment:

[0157] The present invention will be described in detail below with reference to the accompanying drawings and embodiments, and the purpose and effects of the present invention will become more apparent. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0158] The IEEE 6-node power grid system and 8-node heat network system are used to simulate the integrated energy system of the closed mining area. The integrated energy system of the closed mining area serves as a hub, connecting the power and heat networks through the second power grid node and the second heat network node respectively. The first and sixth power grid nodes are connected to two coal-fired units respectively, and the second power grid node is set up with a wind farm. The system application structure is as follows Figure 2 shown.

[0159] The simulation results of the optimization model of the integrated energy system in the closed mining area are as follows: Figure 3-Figure 8 shown.

[0160] Electric power balance Figure 3 As shown, during the period t = 3-6, the user-side power load was low, resulting in excess wind power generation. The WPC-CAES (water pressure compensated constant pressure compressed air storage) compressor started operating, utilizing the excess wind power to begin energy storage, effectively absorbing the redundant wind power. During the period t = 9-13, the user-side power load climbed to its peak, and wind power generation was insufficient to meet the high user load. At this time, the WPC-CAES and the Organic Rankine Cycle (ORC) coordinated with the coal-fired units to jointly participate in peak power generation to meet the high power demand, reducing the total output of the coal-fired units by 124.042 MW. Similarly, during the period t = 18-22, due to the high volatility of wind power generation, it was unable to meet the second peak of user power demand. The turbine, hydro turbine, and ORC once again cooperated with the coal-fired units to meet the power demand. By comparison, it can be found that when the wind power is sufficient, the compressor can utilize redundant wind power to achieve effective energy storage; when wind power is insufficient, the coordinated cooperation of turbines, water turbines and coal-fired units not only meets the power load demand, but also significantly reduces the output of coal-fired units, thereby reducing carbon emissions.

[0161] Heating power Figure 4 As shown in the figure. During the ORC power generation process, at times like t = 2-4, the condenser generates a large amount of waste heat. Furthermore, 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. When the water-source heat pump's ability to "transport" heat energy alone is insufficient to meet the heat load, such as at times like t = 1, 5, and 10, the system extracts heat from the packed bed thermal reservoir to supplement the heat supply gap in the heating network, while retaining the heat energy required by the turbine.

[0162] Figure 5The energy storage state of the shallow mine water reservoir is shown, and its water storage capacity is closely related to the operating conditions of the submersible pump and hydro-generator. During the energy storage phase, when the submersible pump is operating (consuming power), such as at times t = 2-4, it draws water from the geothermal layer and transports it to the shallow mine water reservoir, causing the shallow mine water reservoir to increase in volume. The amount of this increase depends on the power of the submersible pump and is constrained by the upper and lower limits of the reservoir capacity. During the energy release phase, when the submersible pump and hydro-generator are operating simultaneously, if the submersible pump power exceeds the turbine power (in absolute value), the shallow mine water reservoir's water storage capacity increases. Conversely, if the hydro-generator power exceeds the submersible pump power (in absolute value), the shallow mine water reservoir's water storage capacity decreases, such as at times t = 1, 5, and 10.

[0163] Figure 6 and Figure 7 The changes in pressure and gas storage capacity of deep mine compressed air storage are shown respectively. Figure 6 The results show that the deep mine compressed air storage can maintain a stable constant pressure state regardless of changes in the working conditions of the compressor or turbine. Figure 7 This data reflects the changes in the gas storage capacity of deep mine compressed air storage. During the storage phase, when the compressor is running, air is compressed by the compressor and injected into the storage, causing the gas storage capacity to increase, such as at times t = 4-7. During the release phase, when the turbine is running, compressed air is released from the storage into the turbine, driving its power generation, causing the gas storage capacity to decrease, such as at times t = 8 and 10. The specific increase or decrease depends on the power of the compressor / turbine.

[0164] The changes in the heat storage capacity of the packed bed thermal storage are as follows: Figure 8 As shown in the figure. During the energy storage phase, when the compressor is operating, the heat generated by the air being compressed by the compressor is transferred to the heat transfer material as the air flows through the thermal reservoir, causing the thermal reservoir to heat up. However, at time t = 4-5, although the compressor is still operating, the heat it generates is insufficient to offset the heat supplied by the thermal reservoir to the heating network, so the thermal reservoir heat level decreases. During the energy release phase, when the turbine is operating, 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 reservoir, causing the thermal reservoir heat level to decrease.

[0165] Combine 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 operating, not only is compressed air fed into the underground gas storage, but the heat generated during the compression process is also stored in the packed bed thermal reservoir. During the energy release phase, when the turbine is running, the heat in the thermal reservoir is released, providing high-temperature steam for the turbine, thereby increasing its power generation capacity.

[0166] In summary, with the help of compressed air energy storage and pumped hydro, we can balance the intermittency and instability of wind power, improve wind power utilization, reduce the output of coal-fired units, and reduce carbon emissions. At the same time, using ORC to generate electricity and heat is environmentally friendly, promotes cascaded energy utilization, and improves economic efficiency.

[0167] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be employed in conjunction with 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 power generation module, used to convert wind and solar energy into electrical energy through wind turbines and photovoltaic panels and transmit it to the electric bus; Solar thermal collection module, used to convert solar energy into thermal energy to heat mine water, outputting electricity, thermal energy and primary circulating water; An energy storage module is used to maintain a constant pressure of the compressed air generated by the energy regeneration module using the primary circulating water, while also obtaining electrical energy using the primary circulating water; And obtain secondary circulating water to flow back to the mine; The energy regeneration module is used to store heat sources and generate electricity by combining the constant-pressure compressed air obtained by the energy storage module to obtain electrical energy and thermal energy; The energy supply calculation module is used to use the wind and solar energy power generation module, solar thermal collection module, energy storage module and energy regeneration module as energy supply modules, with the goal of minimizing cost, and calculate the output of each energy supply module based on the actual demand for electricity and heat energy.

2. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 1 is characterized in that: The solar heat collection module includes a solar heat collector, an evaporator, a steam turbine, a condenser, a water source heat pump, a condensing heat exchanger and a water source heat exchanger. The head end of the water supply pipeline of the solar collector is used to input mine water, and the end is connected to the water inlet of the evaporator. The water outlet of the evaporator is connected to the water inlet of the water source heat pump. The heat energy obtained by the water source heat pump is transferred to the heat bus through the water source heat exchanger, and the water outlet of the water source heat pump outputs primary circulating water; the water source heat pump is provided with working power by the electric bus; the evaporator outputs steam to the steam turbine, and the steam impacts the steam turbine to generate electricity and transmit it to the electric bus; the steam turbine outputs steam to the condenser, and the condenser outputs organic working fluid to the evaporator; the heat energy obtained by the condenser is transferred to the heat bus through the condensing heat exchanger.

3. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 2 is characterized in that: The energy storage module includes a mine, a submersible pump, a hydro-generator, a shallow mine water reservoir, a deep mine compressed air storage reservoir and a low-temperature waste heat exchanger. The mine water in the mine is input to the head end of the water supply pipeline of the solar collector through a submersible pump, and the outlet of the water source heat pump discharges the primary circulating water into the shallow mine water reservoir. The outlet branch 1 of the shallow mine water reservoir is connected to the hydro-generator, and the electric energy output by the hydro-generator is transmitted to the electric bus, and the secondary circulating water output by the hydro-generator flows back to the mine; the outlet branch 2 of the shallow mine water reservoir is connected to the water inlet of the deep mine compressed air storage reservoir through a check valve; the compressed air inlet of the deep mine compressed air storage reservoir is connected to the compressed gas outlet of the low-temperature waste heat exchanger, and the outlet of the deep mine compressed air storage reservoir is connected to the mine through 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 the compressed air generated by the energy regeneration module, and the compressed air outlet of the deep mine compressed air storage reservoir outputs constant pressure compressed air; The height difference between the shallow mine water reservoir and the deep mine compressed air storage is at least 1,000 meters.

4. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 3 is characterized in that: The energy regeneration module includes a first-stage compressor, a second-stage compressor, a first-stage turbine, a second-stage turbine, a high-temperature packed bed heat storage tank and a medium-temperature packed bed heat storage tank. The first-stage compressor obtains high-temperature compressed air through the electric busbar to provide working power, and stores it in the high-temperature packed bed heat storage reservoir. The heat energy outlet of the high-temperature packed bed heat storage reservoir is connected to the thermal busbar. The hot air outlet one of the high-temperature packed bed heat storage reservoir is connected to the second-stage compressor, and the hot air outlet two is connected to the second-stage turbine. The second-stage compressor obtains medium-temperature compressed air through the electric busbar to provide working power, and stores it in the medium-temperature packed bed heat storage reservoir. The hot air output from the medium-temperature packed bed heat storage reservoir is connected to the compressed air inlet of the deep mine compressed air storage reservoir through the low-temperature waste heat exchanger on the one hand, and the high-temperature compressed air is obtained through the first-stage turbine on the other hand and then stored in the high-temperature packed bed heat storage reservoir. The heat energy outlet of the medium-temperature packed bed heat storage reservoir is connected to the thermal busbar; the electric energy generated by the second-stage turbine is transmitted to the electric busbar; the constant-pressure compressed air output from the compressed air outlet of the deep mine compressed air storage reservoir is transmitted to the medium-temperature packed bed heat storage reservoir.

5. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 4 is characterized in that: In the solar thermal collection module, solar collectors are used to convert solar energy into thermal energy to heat the mine water. The heat absorbed by the mine water is expressed as Q SF : Q SF =Q solar -Q loss -Q pipe (1), Where Q solar The solar energy input to the solar collector, Q loss is the heat loss of the solar collector, Q pipe Heat loss in the water pipeline; The mathematical model of the organic Rankine cycle for heat exchange between heated mine water and organic working fluid is: Where Q eva is the energy absorbed by the organic working medium during the evaporation process, c w is the specific heat capacity of water, m g,w is the mass flow rate of mine water flowing through the evaporator, T g,w,in is the mine water temperature at the evaporator inlet, T g,w,out is the mine water temperature at the outlet of the evaporator, W turb is the power generation of the steam turbine, m f is the mass flow rate of the organic working fluid, h1 is the inlet enthalpy of the organic working fluid of the steam turbine, h2 is the outlet enthalpy of the organic working fluid of the steam turbine, Q con The energy released by the working fluid during the condensation process of the condenser, m w is the mass flow rate of condensed water in the condenser, T w,in is the organic working medium inlet temperature of the condenser, T w,out is the outlet temperature of the organic working fluid in the condenser.

6. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 5 is characterized in that: The calculation method for the volume flow of mine water in shallow mine water storage reservoirs and deep mine compressed air storage reservoirs is: Where W t u is the volume flow of mine water discharged from the shallow mine reservoir at time t, Δt is the time difference between adjacent moments, m g1,w is the mine water flow rate, qm ht,t is the water flow through the turbine generator, W t d is the volume flow rate of mine water discharged from the deep mine compressed air storage at time t, W t in is the water flow from the shallow mine water reservoir to the deep mine compressed air storage, W t out It is the water flow rate flowing out of the deep mine compressed air storage to the mine; Hydrogenerator power generation P ht for: P ht =η ht ·g·h ht ·qm ht,t (4), Where h ht is the efficiency of the turbine generator, g is the acceleration of gravity, h is ht It is the height difference between the shallow mine water reservoir and the hydro-generator.

7. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 6 is characterized in that: The method of establishing the thermal storage model for the high-temperature packed bed thermal storage and the medium-temperature packed bed thermal storage is the same; According to the finite element principle, the high-temperature packed bed heat storage reservoir or the medium-temperature packed bed heat storage reservoir is divided into n increment slices with a thickness of Δz along the height direction. The heat exchange amount ΔQ between the hot air and the filling particles in each increment slice is ex for: In the formula is the volumetric heat transfer coefficient of the packed bed, is the air temperature entering the packed bed thermal storage tank, T s is the temperature of the solid filling particles in the thermal storage, C s is the average cross-sectional area of ​​the packed bed thermal storage; Where G is the core mass velocity of hot air, d a is the average radius of the filling particles; The heat storage state model of the packed bed heat storage at time t is: In the formula is the heat storage capacity of the filled bed thermal storage at time t, is the compressor state variable, which is a 0-1 variable; is the compression heat absorbed by the packed bed thermal storage reservoir at time t, is the turbine state variable, a 0-1 variable; is the heat consumed by the filled bed thermal storage to heat the air at time t, is the output heat of the filled bed thermal storage at time t, is the minimum heat storage capacity of the packed bed thermal storage tank, It is the maximum heat storage capacity of the packed bed thermal storage tank.

8. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 7 is characterized in that: The power consumption of the first-stage compressor or the second-stage compressor at time t is: In the formula is the power consumption of the N-stage compressor at time t, is the adiabatic efficiency of the N-stage compressor, γ is the adiabatic index of air, is the air mass flow consumed by the N-stage compressor at time t, R g is the gas constant, is the inlet air temperature of the N-stage compressor, β j,N is the compression ratio of the N-stage compressor; N-stage compressor outlet air temperature for: The heat absorbed by the high-temperature packed bed heat storage reservoir and the medium-temperature packed bed heat storage reservoir is: In the formula Absorb heat for high temperature packed bed thermal storage, The medium temperature packed bed thermal storage absorbs heat, c a is the specific heat capacity of air, is the first-stage compressor outlet air temperature, is the secondary compressor outlet air temperature, is the temperature of the air flowing out of the medium-temperature packed bed thermal storage reservoir during the energy storage phase; The heat release of high-temperature packed bed heat storage and medium-temperature packed bed heat storage is: In the formula is the heat release of the medium-temperature packed bed thermal storage tank, is the heat released by the high-temperature packed bed heat storage tank, is the air mass flow rate passing through the turbine during period t, is the inlet temperature of the first-stage turbine at time t, is the ambient temperature, is the inlet temperature of the two-stage turbine at time t, is the outlet temperature of the first-stage turbine at time t; Power generation capacity of N-stage turbine for: In the formula is the adiabatic efficiency of the N-stage turbine, is the air mass flow rate flowing through the N-stage turbine at time t, is the inlet temperature of the N-stage turbine at time t, θ j,N is the expansion ratio of the N-stage turbine.

9. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 8, characterized in that: The heat transfer model of the low-temperature waste heat exchanger is: In the formula is the mass flow rate of water at the outlet of the deep mine compressed air storage, is the water temperature at the outlet of the deep mine compressed air storage, T st is the temperature of the deep mine compressed air storage, is the mass flow rate of compressed air flowing out of the medium-temperature packed bed thermal storage reservoir, is the secondary compressor outlet air temperature; Waste heat of mine water from water source heat pump for: In the formula is the mass flow rate of the primary circulating water, is the primary circulating water supply temperature, It is the return water temperature of the first-stage circulating water.

10. The integrated energy supply system based on abandoned resources in closed mining areas according to claim 9, characterized in that: Calculate the minimum sum of the 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 interaction benefit f6 to construct the objective function f: f=min{f1+f2+f3+f4+f5+f6} (15), According to the calculation results of the objective function f, the output of each energy supply module is determined; The cost of pumped storage is the combined cost of submersible pumps, water source heat pumps, hydro-generators, shallow mine water reservoirs and deep mine compressed air storage.

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