Compressed air energy storage system and method based on goaf heat storage regulation and control

Abstract

The embodiment of the invention provides a compressed air energy storage system and method based on goaf heat storage regulation and control. The system is applied to the technical field of compressed air energy storage and comprises a heat storage goaf module, an energy storage sub-module and an energy release sub-module. The method comprises the following steps: in a power consumption trough period, an energy storage sub-module operates to compress ambient air to a high-temperature and high-pressure state; in the power utilization peak period, the energy release sub-module operates, heat energy is transmitted to high-pressure air which is pumped out of the air storage shaft and flows through the energy storage heater, and high-temperature and high-pressure air is formed to drive the turbo expander to generate electricity. After the turbo expander completes power generation, exhausted low-temperature and low-pressure air is introduced into a multi-stage cold energy exchange pipe network buried in the goaf, and an energy closed loop is achieved. In this way, the technical problems that in the prior art, due to inherent intermittency and uncertainty of renewable energy sources, grid-connected consumption is difficult, wind and light abandoning is serious every year, and the peak-valley difference of a power grid tends to be gradually increased can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressed air energy storage, and in particular to a compressed air energy storage system and method based on heat storage regulation in goaf areas. Background Art

[0002] In recent years, the number of abandoned mines has been huge, and the large number of idle abandoned coal mines will cause a huge waste of resources. Using the abandoned mine goaf as heat storage space and utilizing underground spaces such as mine shafts, mining tunnels, and chambers as compressed air storage facilities can greatly reduce the construction cost of compressed air energy storage power stations on the one hand, and realize the development and utilization of abandoned mines on the other hand, which has high economic and social value.

[0003] Wind-solar hybrid systems can increase energy supply, but they still suffer from significant intermittency and uncertainty, and face a mismatch between energy supply and demand. Due to the volatility of wind and solar power, hybrid power generation systems remain highly unstable. The inherent intermittency and uncertainty of renewable energy make grid integration and absorption difficult, leading to significant annual wind and solar curtailment. This problem is further exacerbated by the increasing peak-to-valley variation in power grid performance. Energy storage can effectively alleviate the intermittency, instability, and supply-demand imbalances of wind-solar hybrid systems, and is key to achieving grid integration and absorption of a high proportion of renewable energy. Summary of the Invention

[0004] The present invention provides a compressed air energy storage system and method based on heat storage regulation in goaf areas, which solves the technical problems in the existing technology of the inherent intermittency and uncertainty of renewable energy, resulting in difficulties in grid connection and absorption, serious annual wind and solar power abandonment, and a gradually widening trend of peak-to-valley differences in the power grid.

[0005] According to a first aspect of the present invention, a compressed air energy storage system based on heat storage regulation in goaf is provided, comprising:

[0006] The heat storage goaf module is located in abandoned coal mine goaf and is used to store the compression heat generated by compressed air using water as a heat carrier;

[0007] The energy storage submodule is used to exchange compressed air with thermal energy to form high-temperature and high-pressure air. The high-temperature and high-pressure air drives the turbine expander to generate electricity to provide electrical energy.

[0008] The energy release sub-module is used to provide power to the compressor through an electric motor using the wind-solar complementary system and valley electricity.

[0009] According to a second aspect of the present invention, a compressed air energy storage method based on heat storage regulation in goaf is provided, comprising:

[0010] During periods of low electricity consumption, the energy storage submodule operates, using the surplus electricity from the grid during low load periods and electricity from renewable energy to drive a compressor to compress ambient air to a high-temperature and high-pressure state. The high-temperature and high-pressure air flows through the first and second energy storage heat exchangers and then enters the gas storage wellbore through the gas pipeline. The low-temperature water extracted from the goaf passes through the first and second energy storage heat exchangers, absorbs heat, and then enters the goaf for storage.

[0011] During peak electricity consumption, the energy release module operates, pumping out high-temperature water stored in the goaf through the first-stage and second-stage energy storage heaters, transferring heat energy to high-pressure air pumped from the gas storage wellbore and flowing through the energy storage heaters. This high-temperature, high-pressure air drives the turbine expander to generate electricity.

[0012] When the turbine expander completes power generation, the discharged low-temperature and low-pressure air is introduced into the multi-stage cold energy exchange pipeline network buried inside the goaf to achieve an energy closed loop.

[0013] Compared with the prior art, the advantages and positive effects achieved by the present invention are:

[0014] The present invention

[0015] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other features, advantages and aspects of the embodiments of the present invention will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. The accompanying drawings are provided for a better understanding of the present invention and do not constitute a limitation of the present invention. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, among which:

[0017] Figure 1 A block diagram of a compressed air energy storage system based on goaf heat storage regulation according to an embodiment of the present invention is shown.

[0018] Figure 2 A schematic diagram of a compressed air energy storage system based on heat storage regulation in goaf according to an embodiment of the present invention is shown.

[0019] Figure 3 A flow chart of a compressed air energy storage method based on heat storage regulation in goaf according to an embodiment of the present invention is shown.

[0020] Figure 4 A block diagram is shown of an exemplary electronic device in which embodiments of the present invention can be implemented. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. 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 creative efforts are within the scope of protection of the present invention.

[0022] In this document, the term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0023] Figure 1 FIG. 1 shows a block diagram of a compressed air energy storage system 100 based on heat storage control in goaf according to an embodiment of the present invention. Figure 1 As shown, the system 100 includes:

[0024] The heat storage goaf module 110 is an abandoned coal mine goaf that uses water as a heat carrier to store the compression heat generated by compressed air. It uses an open-loop system, that is, it uses the high specific heat capacity of water to carry heat energy into the goaf to achieve thermal energy storage. When needed, hot water is extracted through a water pump and the water is re-injected into the goaf after heat exchange. Compared with the day and night temperature differences and seasonal temperature differences in the atmospheric environment above the ground, the underground rock and soil serve as a storage body for waste heat resources, which can improve the utilization rate of waste heat resources. The rock strata in the underground space of coal mines are natural energy storage structures with large-scale, cross-temporal and cross-seasonal long-term storage capabilities. The underground space of the goaf formed by mining can be used as a medium for underground thermal energy storage. The heat storage function of the heat storage goaf module 110 is achieved by enriching the water that has been heated after obtaining the compression heat in the goaf.

[0025] The energy storage submodule 120 is used to perform heat exchange between compressed air and thermal energy to form high-temperature and high-pressure air. The high-temperature and high-pressure air generated drives the turbine expander to generate electricity to provide electrical energy.

[0026] Energy storage submodule 120 includes a first-stage compressor 1201, a second-stage compressor 1202, a first energy storage heat exchanger 1203, a second energy storage heat exchanger 1204, a first control valve 1205, and a gas storage wellbore 1206. When heat energy is needed, energy storage submodule 120 uses a heat pump unit to pump high-temperature water stored in the goaf for power generation, heating, and other purposes.

[0027] It should be noted that, in the embodiment, the power supply for the first-stage compressor 1201 and the second-stage compressor 1202 comes from the mains electricity and new energy generation; the input ends of the first-stage compressor 1201 and the second-stage compressor 1202 are connected to the air, the output end of the first-stage compressor 1201 is connected to the input end of the first energy storage heat exchanger 1203, the output end of the first energy storage heat exchanger 1203 is connected to the input end of the second-stage compressor 1202, the output end of the second-stage compressor 1202 is connected to the input end of the second energy storage heat exchanger 1204, the output end of the second energy storage heat exchanger 1204 is connected to the input end of the first control valve 1205, and the output end of the first control valve 1205 is connected to the input end of the gas storage wellbore 1206. The first control valve 1205 is arranged between the output end of the gas of the second energy storage heat exchanger 1204 and the input end of the gas storage wellbore 1206, and is used to control the input end of the gas storage wellbore 1206; the gas storage wellbore 1206 is used to store compressed air; the gas storage wellbore 1206 is used to store high-pressure compressed air, and the gas storage wellbore 1206 uses a polymer material fiberglass as a sealing layer; the (output end) water outlets of the first energy storage heat exchanger 1203 and the second energy storage heat exchanger 1204 are connected to the goaf water inlet pipe, and are connected to the heat storage goaf module 110 through the goaf water inlet pipe.

[0028] During the energy storage process, first control valve 1205 is opened, allowing air to enter first-stage compressor 1201, where it is compressed into high-temperature, high-pressure air. The two air compressors employ a two-stage compression system with intercooling. The output of first-stage compressor 1201 is connected to the input of first energy storage heat exchanger 1203, and the gas output of first energy storage heat exchanger 1203 is connected to the input of second-stage compressor 1202. The output of second-stage compressor 1202 is connected to the input of second energy storage heat exchanger 1204. First-stage compressors 1201 and second-stage compressors 1202 are powered by the power distribution network during off-peak periods. They can also be coupled with other unstable renewable energy sources to absorb off-peak grid loads and waste electricity from renewable energy sources. First-stage compressors 1201 and second-stage compressors 1202 use surplus power from the grid during off-peak periods and power from renewable energy sources to compress the input air, producing high-temperature, high-pressure air.

[0029] The energy release submodule 130 is used to provide power to the compressor through an electric motor using the wind-solar complementary system and valley electricity.

[0030] The energy-releasing submodule 130 includes a first heating heat exchanger 1301, a first expander 1302, a second heating heat exchanger 1303, a second expander 1304, and a second control valve 1305. One inlet of the first heating heat exchanger 1301 is used to obtain heat stored in the heat storage goaf module 110, and the other inlet obtains compressed air. The energy-releasing submodule 130 is used to exchange heat between the compressed air and the heat to form a high-temperature, high-pressure gas for expansion and work. The output of this expansion work drives the generator to generate electricity and provide electrical energy. The water after heat exchange is re-injected into the heat storage goaf module 110. Using two expanders with a heat exchanger placed in between increases the inlet temperature of the next-stage expander and the output work of the expander.

[0031] The input end of the first heating heat exchanger 1301 is connected to the output end of the second control valve 1305, the input end of the second control valve 1305 is connected to the output end of the gas storage wellbore 1206, the output end of the first heating heat exchanger 1301 is connected to the input end of the first expander 1302, the output end of the first expander 1302 is connected to the input end of the second heating heat exchanger 1303, and the output end of the second heating heat exchanger 1303 is connected to the input end of the second expander 1304; the first heating heat exchanger 1301 and the second heating heat exchanger 1303 are connected to the heat storage goaf module 110 through the goaf water inlet pipe.

[0032] During the energy release process, the second control valve 1305 is opened, releasing compressed air from the gas storage wellbore 1206. The compressed air then enters the first heating heat exchanger 1301, where it undergoes heat exchange with the high-temperature water within the heat exchanger. This creates high-temperature, high-pressure gas that enters the first expander 1302, where it expands and produces work. The first expander 1302 outputs this expansion work, which drives the generator to generate electricity, providing power. Excess electricity can be promptly transmitted to the power grid. Furthermore, the exhaust temperature of the compressed air after expansion in the first expander 1302 is relatively low. Therefore, a heat exchanger is placed between the first expander 1301 and the second expander 1302 to raise the inlet temperature of the second expander 1302 and increase the expander's output work.

[0033] It should be noted that in this embodiment, the working principle of the compressed air energy storage system based on heat storage and regulation in goaf can be divided into two core processes: energy storage and energy release. Each module works together to form a complete energy cycle:

[0034] Working principle of the energy storage stage: In the compression and heat storage link, the air is compressed by the first-stage compressor (1201) to form high-temperature and high-pressure gas, which enters the first energy storage heat exchanger (1203) for heat exchange with circulating water, and the compression heat is absorbed by the water to form high-temperature water; the gas after intermediate cooling enters the second-stage compressor (1202) for secondary compression, and is again heat-exchanged through the second energy storage heat exchanger (1204) to form hot water with a higher temperature; the high-temperature water after heat exchange is injected into the heat storage goaf module (110) through a pipeline, and the thermal insulation properties of the underground rock formation are used to achieve long-term storage of thermal energy; at the same time, the cooled high-pressure air is stored in the gas storage wellbore (1206); in terms of energy input characteristics, the power source of the compressor adopts off-peak power of the grid or renewable energy abandoned power to achieve power peak regulation and waste energy consumption.

[0035] Working principle of the energy release phase: In the heat-to-electricity conversion phase, compressed air released from the gas storage wellbore (1206) passes through the first heating heat exchanger (1301) and the second heating heat exchanger (1303) in sequence, where it is heated in two stages with high-temperature water extracted from the goaf, forming a high-temperature, high-pressure working medium. The heated gas drives the first expander (1302) and the second expander (1304) in stages to generate power. The intermediate heat exchange design raises the inlet temperature of the second-stage expander to increase the output power. The low-temperature water after heat exchange is then re-injected into the goaf, completing the heat carrier cycle. The energy output characteristics of the expander are that the output power can be connected to the grid in real time, achieving peak power supply.

[0036] This embodiment utilizes space resources to transform the coal mine goaf into a cross-seasonal heat storage medium, and uses the stable thermal inertia of the rock layer to overcome the environmental heat loss problem of the surface heat storage system, thereby significantly improving the heat storage efficiency. Energy synergy optimization, through the coupling of compressed air energy storage with underground heat storage, realizes the multi-form conversion of electrical energy, thermal energy, mechanical energy, and electrical energy. The two-stage compression / expansion design is combined with intermediate heat exchange to improve the system Efficiency, grid load regulation, and renewable energy absorption capacity are enhanced. Environmental benefits include the reuse of abandoned mine space, which reduces the footprint of surface energy storage facilities. Polymer sealing materials ensure gas storage safety, and the overall system forms a closed-loop clean energy system. Combining the geological characteristics of underground space with compressed air energy storage technology creates a large-scale energy storage solution with cross-seasonal regulation capabilities.

[0037] In existing technologies, frequent inflation and deflation can cause changes in the stress, deformation, and permeability of various structural layers within the wellbore gas storage reservoir, affecting air leakage. Therefore, to control air leakage within acceptable limits, the present invention utilizes a polymer material, fiberglass reinforced plastic, as a sealing layer. During the energy storage and release process, it can provide users with heat and electricity, achieving efficient resource utilization.

[0038] In summary, this embodiment combines the management of abandoned coal mines with the development and utilization of renewable energy, which can not only meet the actual needs of abandoned mine management, but also realize the comprehensive utilization of new energy technologies. Therefore, a compressed air energy storage technology based on heat storage and regulation in goafs can effectively solve the current problems in the fields of abandoned mine management and green energy development and utilization. This embodiment uses the surplus electricity or renewable energy electricity when the grid load is low to compress the air, thereby improving energy utilization; when the power consumption is peak, the high-pressure compressed air is released, and at the same time, the heat energy stored in the goaf is extracted through a heat pump, and high-temperature and high-pressure air is formed through a heat exchanger to drive the turbine expander to generate electricity, thereby realizing the organic combination of electric energy storage and abandoned coal mine management, and playing a certain role in peak shaving and valley filling; the heat energy stored in the goaf can also be used for domestic heating, which is expected to achieve efficient resource utilization.

[0039] The above is an introduction to the method embodiment. The following method embodiment is used to further illustrate the solution of the present invention.

[0040] Figure 2 FIG. 2 shows a flow chart of a compressed air energy storage method 200 based on heat storage control in goaf according to an embodiment of the present invention. Figure 2 As shown, the compressed air energy storage method 200 based on heat storage regulation in goaf includes:

[0041] S210: When the electricity consumption is low, the energy storage submodule operates, using the surplus electricity during the low-load period of the grid and electricity from renewable energy to drive a compressor to compress the ambient air to a high-temperature and high-pressure state. The high-temperature and high-pressure air flows through the first energy storage heat exchanger and the second energy storage heat exchanger, and then enters the gas storage wellbore through the gas pipeline. The low-temperature water extracted from the goaf passes through the first energy storage heat exchanger and the second energy storage heat exchanger, respectively, absorbs heat, and then enters the goaf for storage.

[0042] Optionally, in some embodiments, in S210, an adaptive compression ratio adjustment system is designed based on the dynamic change of the water level in the goaf, and the process of adjusting the compressor output through real-time feedback from the pressure sensor includes the following steps:

[0043] S211: A multi-band sonar array is deployed at the bottom of the gas storage wellbore, emitting acoustic signals of different frequencies that penetrate the wellbore wall and the water in the goaf. By receiving the time-frequency characteristics of the reflected waves, the water level in the goaf and the gas pressure in the gas storage wellbore are analyzed in real time, generating a wellbore pressure fluctuation signal and a dynamic envelope curve of the water level.

[0044] S212: Input the water level dynamic envelope curve into the coupled model of fissure seepage-gas compression, calculate the non-linear relationship between the permeability of the goaf rock mass and the water level change (for example, when the water level rises by 1 m, the permeability decreases by 12-15%), and deduce the maximum safety pressure threshold of the gas storage wellbore at the current water level; at the same time, the main frequency component is extracted from the wellbore pressure fluctuation signal through fast Fourier transform, the pressure oscillation amplitude and phase offset are identified, and a dynamic compression threshold band is generated in combination with the upper limit of the threshold band;

[0045] S213: Install a variable cross-section guide vane group at the air inlet end of gas compression, and its opening and closing angle is regulated in real time by the dynamic compression threshold band:

[0046] When the measured wellbore pressure enters the lower limit area of the threshold band (<P_max - ΔP·cosθ), the vane group expands to the maximum angle (75°), and the compressed air flow rate is increased to 120% of the design value to accelerate energy storage;

[0047] When the pressure approaches the upper limit of the threshold band (>P_max + 0.7ΔP·cosθ), the vane group reduces the compression ratio in a gradient contraction mode (decreasing by 5° every 10 seconds), and the gas flow velocity decays to 80% of the rated value;

[0048] When the pressure stabilizes in the central area of the threshold band, the vane group performs a small-amplitude oscillation (±3°) to cancel the pressure pulsation by actively inducing controllable eddy currents. This process converts the dynamic change of the goaf water level into the basis for the adaptive adjustment of the compression system through the closed-loop feedback of geological parameters, compression control, and energy storage. Compared with the traditional fixed threshold control method, the energy storage efficiency is improved, and the risk of wellbore pressure exceeding the limit is reduced.

[0049] S220: When it is at the peak electricity consumption period, the energy release sub-module operates, pumps out the high-temperature water stored in the goaf, passes it through the first-stage energy storage heater and the second-stage energy storage heater, transfers the heat energy to the high-pressure air flowing through the energy storage heater and pumped out from the gas storage wellbore, and forms high-temperature and high-pressure air to drive the turbine expander to generate electricity.

[0050] Optionally, in some embodiments, in S220, a deep geothermal well group is deployed below the high-temperature water reservoir in the goaf. When the heat storage temperature is lower than the design threshold, the process of starting the geothermal heat supplement system (geothermal water temperature 150-200°C) includes the following steps:

[0051] S221:布设分布式光纤测温阵列在采空区高温水储层内部,通过拉曼散射光信号反演储热层三维温度分布,结合透平膨胀机入口空气温度实时数据,构建储热-释能耦合温度场模型,输出当前热源有效输出功率与设计阈值的差值。

[0052] It should be noted that there is an error in the Chinese in item . The corrected Chinese text is: "布设在采空区高温水储层内部分布式光纤测温阵列,通过拉曼散射光信号反演储热层三维温度分布,结合透平膨胀机入口空气温度实时数据,构建储热-释能耦合温度场模型,输出当前热源有效输出功率与设计阈值的差值。" And the English translation is: "Deploy a distributed optical fiber temperature measurement array inside the high-temperature water reservoir in the goaf, invert the three-dimensional temperature distribution of the heat storage layer through Raman scattered light signals, combine the real-time data of the air temperature at the inlet of the turbine expander, construct a heat storage-energy release coupled temperature field model, and output the difference between the effective output power of the current heat source and the design threshold."S222: Input the difference into the geothermal-heat reservoir permeability coupling equation to calculate the geothermal water injection flow rate and temperature that meet the thermal compensation requirements:

[0053] When the difference is less than or equal to 10% of the design threshold, the fracture conduction module is activated to send low-frequency pulse pressure waves (0.5-2Hz) to the deep geothermal wells, stimulating the expansion of primary fractures in the rock mass and forming a seepage channel that penetrates the geothermal reservoir and the goaf.

[0054] When the difference is greater than 10% of the design threshold, the multi-stage pump group of the geothermal well group is activated, and the water extraction depth is adjusted according to the geothermal water temperature gradient (3.5℃ temperature increase per 100 meters) to stabilize the output geothermal water temperature in the range of 180±5℃;

[0055] When the thermal shortage difference ΔQ ≤ 10% of the design threshold (crack conduction mode):

[0056] Permeability evolution equation:

[0057]

[0058] When the heat shortage difference ΔQ>10% design threshold (pump group regulation mode):

[0059] Geothermal water temperature-depth equation:

[0060]

[0061] Where k(t) represents the dynamic permeability (mD·s -1 ); k0 represents the initial permeability; α represents the thermal-crack coupling coefficient (MW -1 ); β represents the rock mass anti-crack damping coefficient (Pa·s / m); f p represents the pulse pressure wave frequency (Hz); T inj Indicates the geothermal water injection temperature (℃); T b represents the reference geothermal temperature (°C); γ represents the depth-temperature difference gain coefficient (°C / m); h represents the water extraction depth (m);

[0062] Physical meaning of the equation, crack conduction mode equation (ΔQ ≤ 10%), exponential growth characteristics: permeability k (t) increases exponentially with pulse action time t, reflecting the cumulative effect of crack expansion; frequency dependence: pulse frequency f p The higher it is, the faster the permeability increases (needs to match the rock mass resonance frequency to avoid energy dissipation); thermal deficit drive: ΔQ amplifies the crack expansion power through the α coefficient, realizing the coupling of thermal energy and geological transformation.

[0063] Pump group regulation mode equation (ΔQ>10%):, Logarithmic compensation mechanism: When ΔQ / Q th When T increases, injThe growth rate is slowed down to prevent a sudden increase in pump consumption caused by excessive deepening of water wells; depth-temperature nonlinearity: the γ coefficient increases slightly with the increase of h, offsetting the attenuation of the temperature gradient caused by the thermal conductivity loss of the deep rock mass. Dual-mode permeability-temperature coupling breaks through the limitations of a single heat replenishment mode, automatically switches between fracture expansion and active pumping through the ΔQ threshold, taking into account both efficiency and safety; exponential-logarithmic mixed response, the permeability exponential growth responds quickly when the heat deficit is small, and the temperature is logarithmically adjusted to avoid overshoot when the heat deficit is large, forming a stable heat replenishment curve. Geological-thermal closed-loop design, the rock parameters (k0, β) and thermal parameters (ΔQ, T inj ) deep coupling to achieve closed-loop control of "heat shortage drives geological transformation → geological conditions constrain heat supplement efficiency".

[0064] S223: The extracted geothermal water is mixed with the water from the high-temperature water reservoir in the goaf through a cyclone mixing device;

[0065] Geothermal water is injected into the heat storage layer tangentially along the spiral guide vane, and centrifugal force is used to separate high-temperature water (>150℃) and medium-temperature water (80-120℃), forming a radial temperature gradient;

[0066] On the nano-laminated structure surface of the inner wall of the energy storage heater, ions in the geothermal water selectively adsorb onto the coating atoms, reducing the interfacial thermal resistance and increasing the heat transfer flux to 1.3 times that of conventional designs.

[0067] S224: The geothermal water that has completed heat transfer returns to the rock layer 1500-2000m underground through deep reinjection wells, forming a closed-loop geothermal cycle.

[0068] S230: After the turbine expander completes power generation, the discharged low-temperature and low-pressure air is introduced into the multi-stage cold energy exchange pipeline network buried inside the goaf to achieve an energy closed loop.

[0069] Optionally, in some embodiments, the process of designing a fracture network topology optimization algorithm in S230 and intelligently planning the cold energy injection path based on the rock mass permeability distribution model specifically includes the following steps:

[0070] S231: Using a multi-directional acoustic wave transmitting array pre-buried in the collapse zone of the goaf, broadband elastic waves are transmitted to the rock mass. The receiving end uses a polarization-sensitive sensor to capture the wave velocity attenuation and frequency dispersion characteristics. Combined with the initial temperature distribution data of the cold energy exchange pipe network, the fracture density-permeability gradient field is constructed and a three-dimensional gridded permeability parameter matrix is output.

[0071] S232: Input the three-dimensional gridded permeability parameter matrix into the heterogeneous rock mass conductivity model, calculate the fracture conductivity index λ of each grid unit, and generate a λ field distribution cloud map with weighted values;

[0072] The crack extending along the principal stress direction gives a conduction gain of λ + 0.3;

[0073] The cracks with an angle of <45° to the cold energy injection direction are given a flow direction adaptation coefficient of λ+0.2;

[0074] A flow suppression factor of λ-0.4 was applied to areas with a permeability gradient of >5% / m.

[0075] S233: Based on the lambda field distribution cloud map, the turbine exhaust temperature and air flow parameters are loaded on the digital twin platform, and the unsteady thermal-fluid coupling solver is used for iterative calculation to output the optimal path sequence of spatiotemporal evolution.

[0076] Initial stage of cold energy injection (0-2 hours): high-conductivity cracks with λ>0.7 are preferentially filled to form a main channel for rapid cold energy transmission;

[0077] Middle stage of cold energy diffusion (2-6 hours): Extend along the medium-conductivity crack branch with λ = 0.4-0.7, expanding the cold energy coverage;

[0078] Late stage of cold energy equilibrium (>6 hours): pulse boost injection is initiated for the low conduction region with λ<0.4 to force the secondary crack channel to open.

[0079] S234: Compile the optimal path sequence into multi-level vector control instructions to drive the distributed micro-vortex nozzles of the cooling energy exchange network:

[0080] In the high λ region, the laminar flow mode is enabled (Reynolds number Re < 2000), and the nozzle opening is maintained at 80%-100%;

[0081] The mid-λ region switches to turbulence-enhanced mode (Re>4000), increasing the penetration depth of cold energy through high-frequency vibration (50-100Hz);

[0082] The rotary cutting jet mode is activated in the low λ area, and the spiral guide vanes inside the nozzle generate a vortex flow at a speed of 1200 rpm to cut the micro-cracks in the rock mass.

[0083] Optionally, in some embodiments, achieving an energy closed loop specifically includes:

[0084] For deep extraction of waste heat, low-temperature air first flows through the third-stage energy storage heat exchanger to exchange heat with the medium-temperature groundwater pre-stored in the goaf, extracting the waste heat of the air. The groundwater is heated and then injected back into the high-temperature water reservoir in the goaf, thus achieving graded thermal improvement.

[0085] The cold energy rock layer is pre-cooled, and the air that has completed waste heat recovery is injected into the rock fracture network in the collapse zone of the goaf through a distributed injection device, using the huge specific heat capacity and permeable pores of the rock to store cold energy; in the next round of compression stage, the ambient air flows through the cold energy rock layer for pre-cooling before entering the compressor, reducing the compression power consumption.

[0086] This embodiment mainly includes two stages: energy storage and energy release. In the energy storage stage, the surplus electricity during the low load period of the power grid and the electricity from renewable energy are used to drive the compressor. High-pressure compressed air is stored in the gas storage wellbore. The compression heat is stored in the goaf through a heat exchanger, so that the goaf forms a heat storage space. In the energy release stage, the high-pressure compressed air uses the thermal energy stored in the goaf, and is released after being preheated by the heat exchanger to form high-temperature and high-pressure air to drive the turbine expander to generate electricity. In addition, the thermal energy stored in the goaf can also be used for domestic heating. This technology is expected to achieve an organic combination of efficient energy utilization and abandoned coal mine management, promoting sustainable development.

[0087] It should be noted that for the aforementioned method embodiments, for simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should be aware that the present invention is not limited by the order of the actions described, because according to the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0088] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the described module can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0089] According to an embodiment of the present invention, the present invention further provides an electronic device and a readable storage medium.

[0090] Figure 3 A schematic block diagram of an electronic device 300 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0091] The electronic device 300 includes a computing unit 301, which can perform various appropriate actions and processes according to a computer program stored in a ROM 302 or a computer program loaded from a storage unit 308 into a RAM 303. The RAM 303 may also store various programs and data required for the operation of the electronic device 300. The computing unit 301, the ROM 302, and the RAM 303 are connected to each other via a bus 304. An I / O interface 305 is also connected to the bus 304.

[0092] Multiple components in the electronic device 300 are connected to the I / O interface 305, including an input unit 306, such as a keyboard, a mouse, etc.; an output unit 307, such as various types of displays, speakers, etc.; a storage unit 308, such as a magnetic disk, an optical disk, etc.; and a communication unit 309, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 309 allows the electronic device 300 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0093] The computing unit 301 can be any general-purpose and / or specialized processing component with processing and computing capabilities. Some examples of the computing unit 301 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The computing unit 301 performs the various methods and processes described above, such as the method for risk zoning for aircraft flights. For example, in some embodiments, the method for risk zoning for aircraft flights can be implemented as a computer software program tangibly embodied in a machine-readable medium, such as the storage unit 308. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 300 via the ROM 302 and / or the communication unit 309. When the computer program is loaded into the RAM 303 and executed by the computing unit 301, one or more steps of the method for risk zoning for aircraft flights described above can be performed. Alternatively, in other embodiments, the computing unit 301 may be configured in any other appropriate manner (for example, by means of firmware) to execute the method for risk zoning for aircraft flight.

[0094] Various embodiments of the systems and techniques described herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system that includes at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0095] The program code for implementing the method of the present invention can be written in any combination of one or more programming languages. Such program code can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device so that when the program code is executed by the processor or controller, the functions / operations specified in the flow chart and / or block diagram are implemented. The program code can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0096] In the context of the present invention, machine-readable medium can be a tangible medium that can contain or store a program for use with an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0097] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0098] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), and the Internet.

[0099] A computer system may include a client and a server. The client and server are generally remote from each other and typically interact through a communication network. The client-server relationship arises through computer programs running on the respective computers and having a client-server relationship with each other. The server may be a cloud server, a server in a distributed system, or a server integrated with a blockchain.

[0100] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present invention can be achieved. This is not limited herein.

[0101] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A compressed air energy storage system based on heat storage control in goaf, characterized in that: include: The heat storage goaf module is located in abandoned coal mine goaf and is used to store the compression heat generated by compressed air using water as a heat carrier; The energy storage submodule is used to exchange compressed air with thermal energy to form high-temperature and high-pressure air. The high-temperature and high-pressure air drives the turbine expander to generate electricity to provide electrical energy. The energy release sub-module is used to provide power to the compressor through an electric motor using the wind-solar complementary system and valley electricity.

2. The compressed air energy storage system based on heat storage control in goaf according to claim 1 is characterized in that: The energy storage submodule includes: a first-stage compressor, a second-stage compressor, a first energy storage heat exchanger, a second energy storage heat exchanger, a first control valve and a gas storage wellbore; The power supply for the first-stage compressor and the second-stage compressor comes from the mains electricity and new energy power generation; the input ends of the first-stage compressor and the second-stage compressor are connected to the air, the output end of the first-stage compressor is connected to the input end of the first energy storage heat exchanger, the output end of the first energy storage heat exchanger is connected to the input end of the second-stage compressor, the output end of the second-stage compressor is connected to the input end of the second energy storage heat exchanger, the output end of the second energy storage heat exchanger is connected to the input end of the first control valve, and the output end of the first control valve is connected to the input end of the gas storage wellbore; the first control valve is arranged between the output end of the gas of the second energy storage heat exchanger and the input end of the gas storage wellbore, and is used to control the input end of the gas storage wellbore; the gas storage wellbore is used to store compressed air.

3. The compressed air energy storage system based on heat storage control in goaf according to claim 2 is characterized in that: The gas storage wellbore uses a polymer material fiberglass as a sealing layer; the water outlets of the first energy storage heat exchanger and the second energy storage heat exchanger are connected to the goaf water inlet pipe, and are connected to the heat storage goaf module through the goaf water inlet pipe.

4. The compressed air energy storage system based on heat storage control in goaf according to claim 1 is characterized in that: The energy release submodule includes: a first heating heat exchanger, a first expander, a second heating heat exchanger, a second expander and a second control valve; one inlet of the first heating heat exchanger is used to obtain heat stored in the heat storage goaf module, and the other inlet obtains compressed air; The input end of the first heating heat exchanger is connected to the output end of the second control valve, the input end of the second control valve is connected to the output end of the gas storage wellbore, the output end of the first heating heat exchanger is connected to the input end of the first expander, the output end of the first expander is connected to the input end of the second heating heat exchanger, and the output end of the second heating heat exchanger is connected to the input end of the second expander; the first heating heat exchanger and the second heating heat exchanger are connected to the heat storage goaf module through the goaf water inlet pipe.

5. A compressed air energy storage method based on heat storage control in goaf, characterized in that: include: During periods of low electricity consumption, the energy storage submodule operates, using the surplus electricity from the grid during low load periods and electricity from renewable energy to drive a compressor to compress ambient air to a high-temperature and high-pressure state. The high-temperature and high-pressure air flows through the first and second energy storage heat exchangers and then enters the gas storage wellbore through the gas pipeline. The low-temperature water extracted from the goaf passes through the first and second energy storage heat exchangers, absorbs heat, and then enters the goaf for storage. During peak electricity consumption, the energy release module operates, pumping out high-temperature water stored in the goaf through the first-stage and second-stage energy storage heaters, transferring heat energy to high-pressure air pumped from the gas storage wellbore and flowing through the energy storage heaters. This high-temperature, high-pressure air drives the turbine expander to generate electricity. When the turbine expander completes power generation, the discharged low-temperature and low-pressure air is introduced into the multi-stage cold energy exchange pipeline network buried inside the goaf to achieve an energy closed loop.

6. The compressed air energy storage method based on heat storage control in goaf according to claim 5 is characterized in that: In combination with the dynamic changes in the water level in the goaf, an adaptive compression ratio adjustment system is designed. The process of adjusting the compressor output through real-time feedback from the pressure sensor includes the following steps: A multi-band sonar array is placed at the bottom of the gas storage wellbore, emitting acoustic signals of different frequencies that penetrate the wellbore wall and the water in the goaf. By receiving the time-frequency characteristics of the reflected waves, the water level in the goaf and the gas pressure in the gas storage wellbore are analyzed in real time, generating a wellbore pressure fluctuation signal and a dynamic envelope curve of the water level. The water level dynamic envelope curve is input into the fracture seepage-gas compression coupling model to calculate the nonlinear relationship between the permeability of the goaf rock mass and the water level, and to derive the maximum safe pressure threshold of the gas storage wellbore under the current water level. Simultaneously, the wellbore pressure fluctuation signal is subjected to fast Fourier transform to extract the main frequency component, identify the pressure oscillation amplitude and phase offset, and combine the upper limit of the threshold band to generate a dynamic compression threshold band. A variable-section guide vane group is installed at the air inlet end of the gas compression, and its opening and closing angle is controlled in real time by the dynamic compression threshold band.

7. The compressed air energy storage method based on heat storage control in goaf according to claim 6 is characterized in that: When the measured wellbore pressure enters the lower limit of the threshold band, the blade group expands to the maximum angle, increasing the compressed air flow to 120% of the design value; When the pressure approaches the upper limit of the threshold band, the blade group reduces the compression ratio in a gradient contraction mode, causing the gas flow rate to decay to 80% of the rated value; When the pressure stabilizes in the center of the threshold band, the blade group performs micro-oscillations to offset the pressure pulsation by actively inducing controllable vortices.

8. The compressed air energy storage method based on heat storage control in goaf according to claim 5 is characterized in that: A deep geothermal well cluster is deployed below the high-temperature water reservoir in the goaf. When the heat storage temperature falls below the design threshold, the geothermal heating system is activated, including the following steps: A distributed fiber optic temperature measurement array is deployed inside the high-temperature water reservoir in the goaf. The three-dimensional temperature distribution of the heat reservoir is inverted using Raman scattered light signals. Combined with real-time data on the inlet air temperature of the turbine expander, a heat storage-energy release coupled temperature field model is constructed to output the difference between the current effective output power of the heat source and the design threshold. The difference is input into the geothermal-heat reservoir permeability coupling equation to calculate the geothermal water injection flow rate and temperature that meet the thermal compensation requirements; The extracted geothermal water is mixed with the water from the high-temperature water reservoir in the goaf through a cyclone mixing device; The geothermal water that completes the heat transfer returns to the underground rock formation through deep reinjection wells, forming a closed-loop geothermal cycle.

9. The compressed air energy storage method based on heat storage control in goaf according to claim 8 is characterized in that: When the difference is less than or equal to 10% of the design threshold, the fracture conduction module is activated to send low-frequency pulse pressure waves to the deep geothermal wells to stimulate the expansion of primary fractures in the rock mass, forming a seepage channel that penetrates the geothermal reservoir and the goaf. When the difference is greater than 10% of the design threshold, the multi-stage pump group of the geothermal well group is activated and the water extraction depth is adjusted according to the geothermal water temperature gradient.

10. The compressed air energy storage method based on heat storage control in goaf according to claim 8, characterized in that: Geothermal water is injected into the heat storage layer tangentially along the spiral guide vane, and centrifugal force is used to separate high-temperature water from medium-temperature water, forming a radial temperature gradient; On the nano-laminated structure surface of the inner wall of the energy storage heater, ions in the geothermal water are selectively adsorbed by the coating atoms.

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