Abandoned mine pumped storage and geothermal co-development system

Abstract

This utility model discloses a system for the coordinated development of pumped-storage and geothermal energy in abandoned mines. It includes a heat exchange device, a reservoir, and a power station installed on the surface. A vertical shaft, connected to the surface, is drilled at the highest point of the underground reservoir. A hydroelectric power generation device and a pumping device are installed at the lower end of the shaft. The inlet of the hydroelectric power generation device is connected to the outlet of the reservoir, the outlet of the pumping device is connected to the hot water inlet of the heat exchange device, and the cold water outlet of the heat exchange device is connected to the inlet of the reservoir. The hydroelectric power generation device is connected to the power station via a transmission line. This utility model, while realizing the reuse of underground space, constructs a circular system of "underground heat absorption—pumped-storage heat exchange—reinjection power generation." This not only enables the continuous development of low-temperature geothermal energy but also achieves pumped-storage power generation through water circulation, solving the problems of idle space and resource waste in abandoned mines and providing a new technological path for clean energy development and green, low-carbon transformation.

Description

Technical Field

[0001] This utility model belongs to the field of geothermal development and comprehensive utilization technology of coal mining, specifically relating to a system for the coordinated development of pumped storage and geothermal energy in abandoned mines. Background Technology

[0002] While coal mining has long ensured national energy security, it has also resulted in a large number of abandoned mines. After these abandoned mines are closed, their permanent tunnel areas generally suffer from idle space and wasted resources, which not only increases the burden of mine management and maintenance but may also bring environmental and geological disaster risks.

[0003] On the other hand, abandoned mines often possess characteristics such as great depth, high geothermal temperature, and controllable spatial volume, containing significant potential for underground water storage and low-temperature geothermal development. Treating them merely as abandoned projects not only prevents the reuse of vast amounts of underground space but also wastes the geothermal energy stored in the surrounding rock. Meanwhile, the peak-valley difference in my country's power system is continuously widening, urgently requiring the construction of peak-shaving and energy storage facilities to improve the flexibility and security of power grid operation. Traditional pumped-storage power stations are limited in their application in the energy transition of mining areas due to terrain conditions and construction cycles. Utility Model Content

[0004] The purpose of this invention is to provide a system for the coordinated development of pumped storage and geothermal energy in abandoned mines. This system constructs a circular system of "underground heat absorption - pumped heat exchange - reinjection power generation", realizing the coordinated operation of pumped storage and geothermal energy, thereby solving the problems of idle space, resource waste and low energy utilization efficiency in abandoned mines, and providing a new technical path for clean energy development and green and low-carbon transformation.

[0005] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: an abandoned mine pumped storage and geothermal co-development system, in which the permanent roadway area of ​​the abandoned mine is reinforced and seepage-proofed to serve as an underground reservoir, including a heat exchange device, a water storage tank, and a power station installed on the ground. A vertical shaft connected to the ground is opened at the highest point of the underground reservoir. A hydroelectric power generation device and a pumping device are installed at the lower end of the vertical shaft in the underground reservoir. The water inlet of the hydroelectric power generation device is connected to the water outlet of the water storage tank, the water outlet of the pumping device is connected to the hot water inlet of the heat exchange device, and the cold water outlet of the heat exchange device is connected to the water inlet of the water storage tank. The hydroelectric power generation device is connected to the power station through a power transmission line.

[0006] The hydroelectric power generation unit includes a water turbine and a generator installed at the bottom port of a vertical well and located inside an underground reservoir. The water turbine's inlet is connected to a first water pipe, which is equipped with a first solenoid valve. The water turbine's outlet is connected to a second water pipe, which is equipped with a second solenoid valve. The power output shaft of the water turbine is connected to the power input shaft of the generator. The generator is connected to a power collection station located on the ground via a transmission line.

[0007] The pumping device includes a centrifugal pump located inside the underground reservoir. The inlet of the centrifugal pump is connected to a third water pipe, which is equipped with a third solenoid valve. The outlet of the centrifugal pump is connected to a fourth water pipe, which is equipped with a fourth solenoid valve. The outlet of the second water pipe and the inlet of the third water pipe are both connected to a first pumping return pipe that extends below the water surface in the underground reservoir. The vertical well is equipped with a second pumping and return water pipe. The inlet of the second water pipe and the outlet of the fourth water pipe are both connected to the lower part of the second pumping and return water pipe.

[0008] The heat exchange device includes a heat exchange station. The hot water outlet of the heat exchange station is connected to the heating inlet of the geothermal user. The cold water return outlet of the heat exchange station is connected to the cold water return outlet of the geothermal user. The geothermal water inlet of the heat exchange station is connected to a hot water inlet pipe. The inlet of the hot water inlet pipe is connected to the upper port of the second pumping return pipe. The hot water inlet pipe is equipped with a fifth solenoid valve, a pipeline filter, and a pressure gauge. The geothermal water outlet of the heat exchange station is connected to the inlet of the water storage tank through a cold water outlet pipe. The outlet of the water storage tank is connected to a geothermal water return pipe. The outlet of the geothermal water return pipe is connected to the upper port of the second pumping return pipe. The geothermal water return pipe is equipped with a sixth solenoid valve.

[0009] Both the outer surface of the second water return pipe and the outer surface of the hot water inlet pipe are wrapped with thermal insulation cotton.

[0010] By adopting the above technical solution, compared with the prior art, this utility model has the following technical effects: (1) Utilize the permanent roadway area of ​​abandoned mines to construct underground storage areas, transforming abandoned spaces into a composite energy system of pumped storage and geothermal development, thereby realizing the resource utilization of abandoned mines; (2) By combining the pumping and heat exchange during off-peak hours with the reinjection and power generation during peak hours, the coordinated operation of power peak shaving and valley filling and geothermal energy development has been achieved. (3) A circular system of “underground heat absorption - water pumping heat exchange - reinjection power generation” is formed. Each solenoid valve can be automatically controlled by a PLC controller, which has the dual functions of energy storage and clean energy development, and improves the system’s energy efficiency and operating economy. (4) This utility model can be widely applied to various types of abandoned mines such as coal mines, metal mines, and non-metal mines, and has good prospects for promotion and application.

[0011] In summary, this utility model is scientifically sound and easy to construct. While realizing the reuse of underground space, it constructs a circular system of "underground heat absorption - pumping heat exchange - reinjection power generation". This not only enables the continuous development of low-temperature geothermal energy, but also enables pumped storage power generation through water circulation, solving the problems of idle space and resource waste in abandoned mines, and providing a new technical path for clean energy development and green and low-carbon transformation. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0013] like Figure 1 As shown, the abandoned mine pumped storage and geothermal co-development system consists of an underground reservoir 1, which is constructed by reinforcing and preventing seepage in the permanent roadway area of ​​the abandoned mine. The reservoir includes a heat exchange device, a water storage tank 5, and a power station 2 located on the surface. A vertical shaft connected to the surface is located at the highest point of the underground reservoir 1. A hydroelectric power generation device and a pumping device are located at the lower end of the vertical shaft in the underground reservoir 1. The inlet of the hydroelectric power generation device is connected to the outlet of the water storage tank, the outlet of the pumping device is connected to the hot water inlet of the heat exchange device, and the cold water outlet of the heat exchange device is connected to the inlet of the water storage tank. The hydroelectric power generation device is connected to the power station via a power transmission line.

[0014] The hydroelectric power generation unit includes a water turbine 6 and a generator 7 installed at the lower port of a vertical well and located inside an underground reservoir 1. The water inlet of the water turbine 6 is connected to a first water pipe 8, and a first solenoid valve 9 is installed on the first water pipe 8. The water outlet of the water turbine 6 is connected to a second water pipe 10, and a second solenoid valve 11 is installed on the second water pipe 10. The power output shaft of the water turbine 6 is connected to the power input shaft of the generator 7. The generator 7 is connected to a power collection station 2 arranged on the ground 3 through a power transmission line 12.

[0015] The pumping device includes a centrifugal pump 13 located inside the underground reservoir 1. The inlet of the centrifugal pump 13 is connected to a third water pipe 14, and a third solenoid valve 15 is installed on the third water pipe 14. The outlet of the centrifugal pump 13 is connected to a fourth water pipe 16, and a fourth solenoid valve 17 is installed on the fourth water pipe 16. The outlet of the second water pipe 10 and the inlet of the third water pipe 14 are both connected to a first pumping return pipe 18 that extends below the water surface of the underground reservoir 1.

[0016] The vertical well is equipped with a second pumping and return water pipe 19. The inlet of the second water pipe 10 and the outlet of the fourth water pipe 16 are both connected to the lower part of the second pumping and return water pipe 19.

[0017] The heat exchange device includes a heat exchange station 20. The hot water outlet of the heat exchange station 20 is connected to the heating inlet of the geothermal user 21. The cold water return outlet of the heat exchange station 20 is connected to the cold water return outlet of the geothermal user 21. The geothermal water inlet of the heat exchange station 20 is connected to a hot water inlet pipe 22. The inlet of the hot water inlet pipe 22 is connected to the upper port of the second pumping return pipe 19. The hot water inlet pipe 22 is equipped with a fifth solenoid valve 23, a pipe filter 24, and a pressure gauge 25. The geothermal water outlet of the heat exchange station 20 is connected to the inlet of the water storage tank 5 through a cold water outlet pipe 26. The outlet of the water storage tank 5 is connected to a geothermal water return pipe 27. The outlet of the geothermal water return pipe 27 is connected to the upper port of the second pumping return pipe 19. The geothermal water return pipe 27 is equipped with a sixth solenoid valve 28.

[0018] The exterior of the second pumping return pipe 19 and the exterior of the hot water inlet pipe 22 are both wrapped with thermal insulation cotton (not shown in the figure). The thermal insulation cotton can reduce heat loss during the pumping of underground hot water.

[0019] The working process of this utility model includes the following steps: S1. Reinforce and prevent seepage in the permanent roadway area of ​​abandoned mine 1 to make it an underground reservoir for pumped water storage. S2. Water is injected into the underground reservoir and groundwater is replenished. Potential energy is released during the cold water receding process to drive the hydroelectric power generation device to generate electricity, which is then transmitted to the ground-based power station 2. The specific process is as follows: Open the first solenoid valve 9, the second solenoid valve 11 and the sixth solenoid valve 28, and close the fourth solenoid valve 17. Cold water in the reservoir 5 is injected into the turbine 6 through the geothermal water return pipe 27, the second pumping return pipe 19 and the first water pipe 8. The gravitational potential energy generated by the water falling from the ground 3 into the underground reservoir drives the turbine 6 to rotate. The turbine 6 drives the generator 7 to generate electricity. The electrical energy is transmitted to the power station 2 through the transmission line 12. After the cold water flows out of the turbine 6, it flows into the underground reservoir through the second water pipe 10 and the first pumping return pipe 18 for water storage. S3. Water absorbs heat energy from the high-temperature strata in the underground reservoir area and heats up to near the strata temperature. During periods of low electricity demand, the hot water in the underground reservoir area is pumped to the surface 3, and the heat carried by the hot water is extracted through a heat exchange device to realize the development of geothermal energy. The specific process is as follows: Open the third solenoid valve 15, the fourth solenoid valve 17 and the fifth solenoid valve 23, close the sixth solenoid valve 28, the first solenoid valve and the second solenoid valve 11, start the centrifugal pump 13, and transport the geothermal water in the underground reservoir area sequentially from the first pumping return pipe 18, the third water pipe 14, the fourth water pipe 16, the second pumping return pipe 19 and the hot water inlet pipe 22 to the heat exchange station 20. The geothermal water exchanges heat with cold water in the heat exchange station 20. After the cold water is heated, it is delivered to the geothermal user 21 for use. The cooled geothermal water is temporarily stored in the water storage tank 5 through the cold water outlet pipe 26. When the geothermal water passes through the hot water inlet pipe 22, the pipeline filter 24 filters the geothermal water to ensure that the water entering the heat exchange station 20 is free of impurities. At the same time, the pressure gauge 25 monitors the water pressure of the hot water inlet pipe 22 on the inlet side of the pipeline filter 24 in real time. If the pressure exceeds the predetermined pressure, it indicates that the pipeline filter 24 is seriously blocked. When the centrifugal pump 13 is not working, the pipeline filter 24 is repaired or the filter screen is replaced.

[0020] S4. During peak electricity hours, the cold water after heat exchange through the heat exchange device is reinjected from ground surface 3 to the underground reservoir. The potential energy released during the cold water's fall is used to drive the hydroelectric power generation device to generate electricity, thus realizing pumped storage power generation. The specific process is as follows: Open the first solenoid valve 9, the second solenoid valve 11 and the sixth solenoid valve 28, and close the fourth solenoid valve 17. The geothermal water temporarily stored in the reservoir 5 after heat exchange in the heat exchange station 20 is injected into the water turbine 6 through the geothermal water return pipe 27, the second pumping return pipe 19 and the first water pipe 8. The gravitational potential energy generated by the water falling from the ground 3 into the underground reservoir drives the water turbine 6 to rotate. The water turbine 6 drives the generator 7 to generate electricity. The electrical energy is transmitted to the power collection station 2 through the transmission line 12. After the cold water flows out of the water turbine 6, it flows into the underground reservoir through the second water pipe 10 and the first pumping return pipe 18 for water storage.

[0021] S5. Repeat steps S3 and S4 to achieve the cycle of "underground heat absorption - water pumping and heat exchange - reinjection for power generation".

[0022] The above embodiments illustrate the basic principles and features of this utility model. However, the above descriptions are merely preferred embodiments and are not limited to these embodiments. Those skilled in the art, inspired by this patent, can make many modifications and improvements without departing from the spirit and scope of the claims, all of which fall within the protection scope of this utility model. Therefore, the patent and its scope of protection should be determined by the appended claims.

Claims

1. A system for the coordinated development of pumped-storage and geothermal energy in abandoned mines, wherein the permanent roadway areas of abandoned mines are reinforced and seepage-proofed to serve as underground reservoirs for water storage, characterized by: It includes a heat exchange device, a water storage tank, and a power station installed on the ground. A vertical well connected to the ground is opened at the highest point of the underground reservoir. A hydroelectric power generation device and a pumping device are installed at the lower end of the vertical well in the underground reservoir. The water inlet of the hydroelectric power generation device is connected to the water outlet of the water storage tank. The water outlet of the pumping device is connected to the hot water inlet of the heat exchange device. The cold water outlet of the heat exchange device is connected to the water inlet of the water storage tank. The hydroelectric power generation device is connected to the power station through a power transmission line.

2. The abandoned mine pumped storage and geothermal co-development system according to claim 1, characterized in that: The hydroelectric power generation unit includes a water turbine and a generator installed at the bottom port of a vertical well and located inside an underground reservoir. The water turbine's inlet is connected to a first water pipe, which is equipped with a first solenoid valve. The water turbine's outlet is connected to a second water pipe, which is equipped with a second solenoid valve. The power output shaft of the water turbine is connected to the power input shaft of the generator. The generator is connected to a power collection station located on the ground via a transmission line.

3. The abandoned mine pumped storage and geothermal co-development system according to claim 2, characterized in that: The pumping device includes a centrifugal pump located inside the underground reservoir. The inlet of the centrifugal pump is connected to a third water pipe, which is equipped with a third solenoid valve. The outlet of the centrifugal pump is connected to a fourth water pipe, which is equipped with a fourth solenoid valve. The outlet of the second water pipe and the inlet of the third water pipe are both connected to a first pumping return pipe that extends below the water surface in the underground reservoir. The vertical well is equipped with a second pumping and return water pipe. The inlet of the second water pipe and the outlet of the fourth water pipe are both connected to the lower part of the second pumping and return water pipe.

4. The abandoned mine pumped storage and geothermal co-development system according to claim 3, characterized in that: The heat exchange device includes a heat exchange station. The hot water outlet of the heat exchange station is connected to the heating inlet of the geothermal user. The cold water return outlet of the heat exchange station is connected to the cold water return outlet of the geothermal user. The geothermal water inlet of the heat exchange station is connected to a hot water inlet pipe. The inlet of the hot water inlet pipe is connected to the upper port of the second pumping return pipe. The hot water inlet pipe is equipped with a fifth solenoid valve, a pipeline filter, and a pressure gauge. The geothermal water outlet of the heat exchange station is connected to the inlet of the water storage tank through a cold water outlet pipe. The outlet of the water storage tank is connected to a geothermal water return pipe. The outlet of the geothermal water return pipe is connected to the upper port of the second pumping return pipe. The geothermal water return pipe is equipped with a sixth solenoid valve.

5. The abandoned mine pumped storage and geothermal co-development system according to claim 4, characterized in that: Both the outer surface of the second water return pipe and the outer surface of the hot water inlet pipe are wrapped with thermal insulation cotton.

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