Energy storage system based on outdoor abandoned mine pit reconstruction

Abstract

The energy storage system comprises an underground pumped storage lower reservoir, an underground pumped storage upper reservoir and an underground pumped storage plant, and the underground pumped storage lower reservoir, the underground pumped storage upper reservoir and the underground pumped storage plant jointly form an underground pumped storage power station. An open-air abandoned mine pit is transformed to form upper and lower reservoirs with different heights at the same horizontal position, the upper and lower reservoirs are separated through reinforced concrete walls, and a horizontal tunnel is laterally excavated at the bottom of the mine pit, so that the capacity of the underground reservoir is increased. In an area with soft geology, a submerged plant is built at the bottom of an underground pumped storage lower reservoir, or a scheme of prefabricating a concrete water storage tank is adopted, and a pump turbine and a motor generator cabin are directly and integrally mounted at the top of the water tank when the concrete water tank is prefabricated. An open-air waste mine pit is transformed into a heat storage system, a heat storage reservoir is formed after the open-air waste mine pit is subjected to side slope water prevention and seepage prevention, and comprehensive heat storage in various modes is carried out through heating and industrial waste heat collection in non-heat-supply time.

Description

Technical Field

[0001] The utility model belongs to the field of energy storage, and in particular relates to an energy storage system based on the transformation of an abandoned open-pit mine. Background Art

[0002] Open-pit mine remediation has received considerable attention in recent years. Chinese patent application CN202111236946.4 proposes a method for constructing a large-span underground space based on an open-pit mine, but does not specify the purpose of the underground space. Chinese patent application 201220058445.1 proposes a solar photovoltaic power generation device based on a flooded open-pit mine. This effectively utilizes the flooded surface of the open-pit mine, which is extremely difficult to develop. This effectively addresses the installation and service life issues of power stations caused by the complex geology of subsequent mine collapse areas, and effectively addresses the issues of intensive and efficient implementation and subsequent maintenance in photovoltaic power station construction. However, filling the open-pit mine requires a large amount of water, and severe evaporation in certain areas makes it difficult to maintain a constant water level within the mine. Furthermore, the open-pit mine, its internal volume, and the water are not fully utilized. Chinese patent applications 201810752415.2, 201810752990.2, and 202010231702.6 propose the use of open-pit abandoned mines to build pumped-storage power stations. However, in order to achieve the height difference between the upper and lower reservoirs, only a portion of the space at the bottom and top of the open-pit abandoned mines is utilized, and the remaining underground space resources are not fully utilized, resulting in serious waste. The slopes corresponding to the unused portions still require subsequent maintenance, which is very expensive. In addition, the construction of large dams requires a large amount of steel, which is also very expensive. Moreover, the geological conditions at the bottom of some abandoned mines are soft and unsuitable for the construction of large-scale underground powerhouses for pumped storage. Therefore, there are obstacles to the implementation of these patent applications. Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides an energy storage system based on the transformation of open-pit abandoned mines.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] An energy storage system based on the transformation of an abandoned open-pit mine, comprising an underground pumped storage lower reservoir, an underground pumped storage upper reservoir, and an underground pumped storage plant, to achieve underground pumped storage power generation;

[0006] An underground pumped storage lower reservoir and an underground pumped storage upper reservoir are set up at different heights at the same horizontal position of the open-pit abandoned mine;

[0007] Concrete columns are constructed on the bottom plate of the underground pumped storage lower reservoir, the concrete columns support the concrete load-bearing layer, and the ventilation shaft passes through the concrete load-bearing layer and is connected to the underground pumped storage lower reservoir;

[0008] A reservoir cover is installed on the upper part of the underground pumped storage reservoir to prevent water evaporation and freezing in winter. The upper part of the reservoir cover is covered with soil and a photovoltaic power station and a solar water heater station are built. The solar water heater heats the upper reservoir of the underground pumped storage reservoir to prevent freezing in winter.

[0009] There is a ventilation shaft between the underground pumped storage reservoir and the ground, which also serves as a maintenance passage;

[0010] The underground pumped storage power plant is built underground and is connected to the underground pumped storage lower reservoir and the underground pumped storage upper reservoir through water pipelines.

[0011] Furthermore, the underground pumped storage lower reservoir is a spherical or arched steel-concrete structure, and a covering soil layer is provided above the concrete bearing layer.

[0012] Furthermore, the underground pumped storage lower reservoir and the underground pumped storage upper reservoir are separated by an arched or spherical concrete wall.

[0013] Furthermore, the underground pumped storage lower reservoir is formed by placing prefabricated concrete water tanks directly on the bottom of the open-pit abandoned mine, and is separated from the underground pumped storage upper reservoir by covering soil.

[0014] Furthermore, horizontal tunnels are excavated laterally at the bottom of the mine to increase the capacity of the underground pumped-storage reservoir.

[0015] Furthermore, in areas with soft geology, a submerged powerhouse is built at the bottom of the underground pumped storage reservoir, or a precast concrete water storage tank is used, and the compartments of the pump turbine and the electric generator are directly integrated and installed on the top of the precast concrete water tank.

[0016] The utility model also provides another energy storage system based on the transformation of an open-pit abandoned mine, which includes a water storage reservoir, a heating device, and a water delivery device, which are used together for heat storage;

[0017] After slope waterproofing and anti-seepage measures are taken, abandoned open-pit mines are formed into hot water reservoirs, which are heated by circulating water pumps through heating devices or by solar water heaters. During non-heating periods, industrial waste heat is used for comprehensive heat storage in various ways, or the waste heat is heated by heat pumps and stored in the hot water reservoir. The hot water reservoir is covered with a reservoir cover for insulation, and soil is placed on top of the reservoir cover to construct a photovoltaic power station and a solar water heater station. Concrete columns are built on the bottom plate of the underground pumped storage reservoir, supporting a concrete load-bearing layer, above which is a soil layer. The heating device includes multiple layers of heaters distributed from top to bottom in the reservoir to control the gradient distribution of the water temperature in the reservoir from top to bottom.

[0018] A dam is built inside an abandoned open-pit mine to divide the hot water reservoir into two reservoirs, a hotter reservoir and a colder reservoir. During the heating process, the water in the colder reservoir enters the hotter reservoir after being heated. Hot water is taken directly from the hotter reservoir. After being heated for users, the water temperature drops and enters the colder reservoir.

[0019] Furthermore, an underground pumped storage lower reservoir, an underground pumped storage upper reservoir, and an underground pumped storage plant are set up to together constitute an underground pumped storage and heat storage comprehensive energy storage system; the underground pumped storage lower reservoir is formed by placing a spherical or cylindrical prefabricated concrete water tank at the bottom of an abandoned open-pit mine; the underground pumped storage plant is set at the bottom of the underground pumped storage lower reservoir.

[0020] Furthermore, an underground pumped storage lower reservoir is built at the bottom of the abandoned open-pit mine, separated from the hot water storage reservoir built above the abandoned open-pit mine; the pumped storage lower reservoir is used for pumped storage and power generation, and the water in the hot water storage reservoir is used for heat storage after being heated and insulated.

[0021] Furthermore, a water-blocking dam is built above the covering soil layer to form an underground pumped storage upper reservoir and a hot water storage reservoir respectively. The ventilation shaft passes through the concrete bearing layer, the covering soil layer, the water-blocking dam and is connected to the underground pumped storage reservoir.

[0022] Beneficial effects:

[0023] (1) Pumped storage is the most ideal way to store electricity, but the number of sites where pumped storage can be built is limited; heat storage is an important way to store energy, and its energy storage per unit volume is higher than that of pumped storage. This utility model forms an energy storage system based on the transformation of open-pit abandoned mines by rationally utilizing the volume of abandoned mines, and rationally utilizes the volume of abandoned mines to form heat storage reservoirs and underground pumped water reservoirs.

[0024] (2) Appropriate slope management and waterproofing and anti-seepage measures can ensure good economic efficiency of the system.

[0025] (3) For mines with a limited depth of 200 to 300 meters, only the bottom is used as a pumped storage reservoir to increase the available water head.

[0026] (4) Heat storage is not affected by the depth of the mine. The heat storage capacity is related to the volume of the reservoir. Therefore, building a heat storage reservoir on the upper layer can make full use of the underground space resources formed by the abandoned open-pit mine.

[0027] (5) Rationally solve the problem of large capital investment and small returns in the treatment of abandoned mines, and realize the utilization and income generation of abandoned resources through large-volume water body heat storage and underground pumped water storage.

[0028] (6) In view of the fact that the geological conditions at the bottom of the mine are not suitable for the construction of underground powerhouses, a submerged underground powerhouse is proposed, which can solve the problem that the soft geological conditions are not suitable for the construction of pumped storage underground powerhouses.

[0029] (7) Build a double-layer reservoir to rationally utilize the volume of abandoned open pit mines. This structure is completely different from the structure of a dam and can minimize tensile forces. Taking advantage of the strong compressive strength of concrete, the upper and lower reservoirs are supported by a small amount of steel-concrete structure and isolated by covering with soil, reducing the use of steel-concrete structure and saving costs. Horizontal tunnels can be excavated laterally at the bottom of the mine to increase the capacity of the underground reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of an underground pumped water storage system based on the transformation of an abandoned open pit mine in the present invention;

[0031] Figure 2 It is a schematic diagram of the underground water reservoir of the utility model;

[0032] Figure 3 It is a schematic diagram of the submerged powerhouse of the utility model;

[0033] Figure 4 It is a schematic diagram of the lower reservoir of the utility model;

[0034] Figure 5 This is a schematic diagram of the utility model's water pump being heated by a circulating electric heater;

[0035] Figure 6 A schematic diagram of the direct electric heater heating of the utility model;

[0036] Figure 7 A schematic diagram of the hybrid heating system of the utility model;

[0037] Figure 8 Schematic diagrams of the construction of the hot and cold water pools of the utility model;

[0038] Figure 9 This is a schematic diagram of the utility model's water pump being heated by a circulating electric heater;

[0039] Figure 10 A schematic diagram of the hybrid heating system of the utility model;

[0040] Figure 11 It is a schematic diagram of a single-layer double reservoir of the utility model;

[0041] Figure 12 Another schematic diagram of the utility model single-story double-reservoir, submerged powerhouse;

[0042] Figure 13 This is another schematic diagram of the concrete storage tank lower reservoir of the utility model.

[0043] The figures are as follows: first lower reservoir 101, first concrete column 102, first concrete load-bearing layer 103, first covering layer 104, upper reservoir 105, pumped storage power plant 106, first water pipeline 107, second water pipeline 108, first ventilation shaft 109, first reservoir cover 110, first photovoltaic panel 111, first solar water heater 112, first traffic road 113, second traffic road 114, tunnel 115, second lower reservoir 116, first submerged Factory building 201, first precast concrete water tank 301, first cabin 302, first pipeline 303, first ventilation duct 304, second cover layer 305, third traffic channel 306, water reservoir 401, second reservoir cover 402, second photovoltaic panel 403, second pipeline 404, first water pump 405, first heater 406, second solar water heater 407, third pipeline 408, second water pump 409, return pipe 410, third water pump 411, upper heater 501 , lower heater 502, dam 601, hot water reservoir 602, cold water reservoir 603, pumped storage lower reservoir 701, second concrete column 702, second concrete bearing layer 703, fourth cover layer 704, first hot water reservoir 705, first pumped storage upper reservoir 706, pumped storage powerhouse 707, water pipeline 708, second ventilation shaft 709, fifth pipeline 710, fourth water pump 711, second heater 712, third reservoir cover 713, third solar Water heater 714, fourth water pump 715, sixth pipeline 716, fifth water pump 717, pumped storage upper reservoir cover 718, second photovoltaic panel 719, upper heater 801, lower heater 802, dam 901, second pumped storage upper reservoir 902, second hot water storage reservoir 903, second submerged plant 1001, second precast concrete water tank 1101, second cabin 1102, seventh pipeline 1103, third ventilation duct 1104, fifth covering soil layer 1105. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0045] Example 1:

[0046] like Figure 1As shown, after slope management and infrastructure renovation, the abandoned open-pit mine has been divided into multiple layers. A first lower reservoir 101, used for pumped storage, is constructed with first concrete columns 102 supporting a first concrete load-bearing layer 103. Above this first concrete load-bearing layer 103 is a first overburden layer 104, and above this is an upper reservoir 105. A pumped-storage powerhouse 106 is built underground and connected to the first lower reservoir 101 and upper reservoir 105 via a first water pipeline 107 and a second water pipeline 108, respectively. A first ventilation shaft 109 connects the outside world to the first lower reservoir 101 and can also be used for maintenance, enabling underground pumped-storage power generation.

[0047] The first reservoir cover 110 covers the upper reservoir 105 to prevent water evaporation and prevent freezing in winter. The first reservoir cover 110 is covered with soil. In order to make rational use of the land, the first photovoltaic panel 111 and the first solar water heater 112 are arranged on the first reservoir cover 110 to supply factory electricity and hot water. The excess electricity can be connected to the Internet. In addition, part of the hot water from the first solar water heater 112 can enter the upper reservoir 105 to heat the upper reservoir 105 and prevent it from freezing in winter.

[0048] In addition, a first traffic channel 113 and a second traffic channel 114 are set up underground. The first traffic channel 113 leads to the pumped storage power plant 106, and the second traffic channel 114 leads to the first lower reservoir 101. A tunnel 115 is excavated from the bottom of the first lower reservoir 101 to expand the storage capacity of the first lower reservoir 101.

[0049] Preferably, the covering soil layer 104 can also be eliminated according to specific circumstances and directly connected to the upper reservoir 105.

[0050] like Figure 2 As shown, the first lower reservoir 101 is replaced by the second lower reservoir 116, which is arched or spherical and equipped with a corresponding reinforced concrete structure, which is expected to further reduce the construction cost of the lower reservoir. In addition, the first covering layer 104 can be omitted, and the upper reservoir and the lower reservoir are directly separated by an arched or spherical concrete wall.

[0051] like Figure 3 As shown, in areas with soft geology, it is not suitable to build an underground pumped storage power plant, or in order to save the construction cost of the underground power plant, the underground power plant can be directly built at the bottom of the first lower reservoir 101 to form a first submerged power plant 201.

[0052] like Figure 4 As shown, in areas with soft geology, it is not suitable to build underground pumped storage power plants, or in order to save the construction cost of underground power plants, a precast concrete water storage tank solution can be adopted, and when precasting the concrete water storage tank, the pump turbine and the motor generator cabin can be directly integrated and installed at the bottom of the precast concrete water storage tank.

[0053] The lower reservoir adopts a spherical or cylindrical first precast concrete water tank 301, which is placed at the bottom of the open-pit abandoned mine. The upper part of each first precast concrete water tank 301 is installed with a first compartment 302 of an electric generator and a water pump turbine, which is connected to the upper reservoir 105 through a first pipe 303 to form an underground pumped storage system. The first ventilation pipe 304 is connected to each precast first precast concrete water tank 301 and can also be used for maintenance. In order to save costs, after the precast concrete water tanks are arranged, they are surrounded by soil to form a second soil layer 305, which is separated from the upper reservoir 105 and the hot water storage reservoir. In addition, a third traffic channel 306 is set for the maintenance of the lower reservoir and the first compartment 302.

[0054] Example 2:

[0055] like Figure 5 As shown, reservoir 401 is a heat storage reservoir in an abandoned open-pit mine that has undergone slope management and waterproofing and anti-seepage renovations. Reservoir 401 has an insulated second reservoir cover 402. After being covered with soil, a large number of second photovoltaic panels 403 can be placed on top of second reservoir cover 402, effectively utilizing the land. The water temperature in reservoir 401 is distributed in a gradient from top to bottom. Cooler water is located at the bottom of the reservoir and can be circulated and heated by a first water pump 405 through a first heater 406. This water is pumped through a second pipe 404, pumped by the first water pump 405, and heated in the first heater 406. First heater 406 can be an electric heater, capable of flexibly adjusting its power based on the output characteristics of renewable energy and electricity prices. It can also flexibly adjust its power in response to changes in renewable energy and load to provide auxiliary services to the power grid. The heated water then returns to the upper portion of reservoir 401, completing the heating and heat storage. In addition, the water body can be heated by arranging a portion of the second solar water heater 407 on the second reservoir cover 402. The water pipes of the second solar water heater 407 are connected to different water depths of the water storage reservoir 401. According to the gradient distribution of water temperature, the water temperature at deeper locations is lower, and the water temperature at shallower locations is higher. After the water in the second solar water heater 407 is heated, it flows naturally and transports the heated water to the upper layer of the water storage reservoir 401, while continuing to heat the deeper reservoir water. In addition, a water pump can be used to assist in water pumping and heating for the second solar water heater 407.

[0056] During heating, the warmer water near the top of reservoir 401 is pumped through third pipe 408 and second water pump 409 to the heating load. After heating, the water cools down and returns to reservoir 401 via return pipe 410. Furthermore, on non-heating days, water from the hot water reservoir is pumped through third pump 411 to an industrial waste heat source. After heating, it is stored in reservoir 401 through third pipe 408 in preparation for the heating period.

[0057] like Figure 5 、 Figure 6 As shown, to further reduce the investment and energy costs of the first water pump 405, the heating device of the water reservoir 401 is modified to employ direct electric heaters. Heating devices are arranged at different depths, either on the slope or parallel to the water surface, for uniform distribution. Specifically, the heating device includes an upper heater 501 and a lower heater 502. Through coordinated control, the temperature gradient within the water reservoir 401 is controlled. Furthermore, heaters at different depths can be added as needed.

[0058] like Figure 5 、 Figure 6 , Figure 7 As shown, both pumping heating (i.e., through the second pipe 404, extracted by the first water pump 405, and heated in the first heater 406) and direct heating (directly heated by the upper heater 501 and the lower heater 502) can be used simultaneously. The two heating paths are coordinated to meet the gradient distribution requirements of the water temperature in the water reservoir 401.

[0059] like Figure 8 As shown, by building a dam 601 inside an abandoned open-pit mine, the hot water reservoir is divided into two reservoirs, namely a hotter water reservoir 602 and a colder water reservoir 603. During the heating process, the water in the colder water reservoir 603 enters the hotter water reservoir 602 after being heated. Hot water is directly taken from the hotter water reservoir 602. After being heated for users, the water temperature drops and enters the colder water reservoir 603.

[0060] Example 3:

[0061] like Figure 9 As shown, after slope management and infrastructure renovation, the open-pit abandoned mine is divided into multiple layers. The pumped storage lower reservoir 701 is built by the second concrete column 702 and the second concrete bearing layer 703, above which is the fourth covering soil layer 704, and above that is the first hot water storage reservoir 705.

[0062] The first pumped-storage upper reservoir 706 is built on the ground, and the pumped-storage plant 707 is built underground. They are connected to the pumped-storage lower reservoir 701 and the first pumped-storage upper reservoir 706 through a water pipeline 708 respectively. The second ventilation shaft 709 connects the outside world and the pumped-storage lower reservoir 701, and can also be used for maintenance purposes, forming an underground pumped-storage power station.

[0063] The water temperature in the first hot water storage reservoir 705 is distributed in a gradient from top to bottom, with the cooler water at the bottom of the first hot water storage reservoir 705. During heat storage, the water is circulated and heated by the fourth water pump 711 through the second heater 712. Specifically, the water passes through the fifth pipe 710, is pumped by the fourth water pump 711, and is heated in the second heater 712. The second heater 712 can be an electric heater, and its power can be flexibly adjusted based on the output characteristics of renewable energy and electricity prices. It can also flexibly adjust its power in response to changes in renewable energy and load to provide auxiliary services to the power grid, coordinating with the output power of underground pumped storage. Afterwards, the heated water returns to the upper portion of the first hot water storage reservoir 705, completing the heating of the water and completing the heat storage. In addition, water can be heated by a third solar water heater 714, which is arranged on the third reservoir cover 713. The water pipes of the third solar water heater 714 are connected to different depths of the reservoir. According to the water temperature gradient, the water temperature is lower at deeper depths and higher at shallower depths. After being heated, the water in the third solar water heater 714 flows naturally, transporting the heated water to the upper layer of the first hot water reservoir 705 while continuing to heat the water in the deeper first hot water reservoir 705. Furthermore, a water pump can be used to assist in pumping water for heating the third solar water heater 714. Furthermore, on non-heating days, the cooler water is pumped to the industrial waste heat source via the fifth pipe 710 and the fourth water pump 715. After being heated, it is stored in the first hot water reservoir 705 via the sixth pipe 716, completing the heat storage and preparing for the heating period. During heating, the water with higher temperature near the upper surface of the first hot water storage reservoir 705 passes through the sixth pipe 716 and is pumped to the heating load by the fifth water pump 717. After heating, the water temperature becomes lower and returns to the first hot water storage reservoir 705 through the fifth pipe 710.

[0064] The third reservoir cover 713 has the function of insulation and is covered with soil. The function of the pumped storage upper reservoir cover 718 is to prevent water evaporation and prevent freezing in winter. In order to make rational use of land, the third reservoir cover 713 and the pumped storage upper reservoir cover 718 are arranged with a second photovoltaic panel 719 and a third solar water heater 714.

[0065] like Figure 10 As shown, direct electric heaters can also be used for heating. Heating devices can be arranged at different depths within the first hot water reservoir 705. The heating devices can be arranged on the slope or parallel to the water surface for uniform distribution. The heating devices include an upper heater 801 and a lower heater 802. Through coordinated control, the gradient distribution of the water temperature within the first hot water reservoir 705 is controlled. In addition, heaters at different depths can be added according to actual needs.

[0066] like Figure 11As shown, the upper layer can be divided into two reservoirs by a dam 901, namely a second pumped storage upper reservoir 902 and a second hot water storage reservoir 903, eliminating the need to build an above-ground reservoir.

[0067] like Figure 12 As shown, in areas with soft geology, it is not suitable to build an underground pumped storage power plant, or in order to save the construction cost of the underground power plant, the underground power plant can be directly built at the bottom of the pumped storage reservoir to form a second submerged power plant 1001.

[0068] like Figure 13 As shown, in areas with soft geology, it is not suitable to build underground pumped storage powerhouses, or in order to save the construction cost of underground powerhouses, a prefabricated concrete water storage tank solution can be adopted, and the water pump turbine and electric generator cabin can be directly integrated and installed on the top of the water tank when prefabricating the concrete water tank.

[0069] The pumped-storage lower reservoir adopts a spherical or cylindrical second precast concrete water tank 1101 placed at the bottom of the open-pit abandoned mine. The lower part of each second precast concrete water tank 1101 is installed with a second compartment 1102 of an electric generator and a water pump turbine, which is connected to the upper reservoir through a seventh pipe 1103 to form an underground pumped-storage system. The third ventilation pipe 1104 is connected to each second precast concrete water tank 1101 and can also be used for maintenance. In order to save costs, after the precast concrete water tanks are arranged, they are covered with soil to form a fifth covering layer 1105, which is separated from the underground pumped-storage upper reservoir and the hot water storage reservoir.

Claims

1. An energy storage system based on the transformation of an abandoned open-pit mine, characterized in that: It includes an underground pumped storage lower reservoir, an underground pumped storage upper reservoir, and an underground pumped storage plant to realize underground pumped storage power generation; An underground pumped storage lower reservoir and an underground pumped storage upper reservoir are set up at different heights at the same horizontal position of the open-pit abandoned mine; Concrete columns are constructed on the bottom plate of the underground pumped storage lower reservoir, the concrete columns support the concrete bearing layer, and the ventilation shaft passes through the concrete bearing layer and is connected to the underground pumped storage lower reservoir; A reservoir cover is installed on the upper part of the underground pumped storage reservoir to prevent water evaporation and freezing in winter. The upper part of the reservoir cover is covered with soil and a photovoltaic power station and a solar water heater station are built. The solar water heater heats the upper reservoir of the underground pumped storage reservoir to prevent freezing in winter. There is a ventilation shaft between the underground pumped storage reservoir and the ground, which also serves as a maintenance passage; The underground pumped storage power plant is built underground and is connected to the underground pumped storage lower reservoir and the underground pumped storage upper reservoir through water pipelines.

2. The energy storage system based on the transformation of an abandoned open-pit mine according to claim 1 is characterized in that: The underground pumped storage reservoir is a spherical or arched steel-concrete structure with a covering soil layer above the concrete bearing layer.

3. The energy storage system based on the transformation of an abandoned open-pit mine according to claim 1 is characterized in that: The underground pumped storage lower reservoir and the underground pumped storage upper reservoir are separated by an arched or spherical concrete wall.

4. The energy storage system based on the transformation of an abandoned open-pit mine according to claim 1 is characterized in that: The underground pumped storage lower reservoir is formed by placing precast concrete water tanks directly at the bottom of an open-pit abandoned mine, and is separated from the underground pumped storage upper reservoir by covering soil.

5. The energy storage system based on the transformation of an abandoned open-pit mine according to claim 1 is characterized in that: A horizontal tunnel is excavated laterally at the bottom of the mine to increase the capacity of the underground pumped storage reservoir.

6. The energy storage system based on the transformation of an abandoned open-pit mine according to claim 1 is characterized in that: In areas with soft geology, a submerged powerhouse is built at the bottom of the underground pumped storage reservoir, or a precast concrete water storage tank is used, and the compartments of the pump turbine and electric generator are directly integrated and installed on the top of the precast concrete water tank.

7. An energy storage system based on the transformation of an abandoned open-pit mine, characterized in that: It includes a water storage reservoir, a heating device, and a water delivery device, which are used together to store heat; After slope waterproofing and anti-seepage measures are taken, abandoned open-pit mines are transformed into hot water reservoirs, which are heated by circulating water pumps through heating devices or by solar water heaters. During off-season, industrial waste heat is used for comprehensive heat storage in various ways, or waste heat is used to heat water via heat pumps and stored in the hot water reservoir. The hot water reservoir is covered with a reservoir cap for insulation, and soil is placed on top of the cap to build a photovoltaic power station and a solar water heater station. Concrete columns are constructed on the bottom plate of the underground pumped storage reservoir, supporting a concrete load-bearing layer above which is a covering soil layer. The heating device comprises multiple layers of heaters distributed from top to bottom in the reservoir, controlling the gradient distribution of water temperature from top to bottom in the reservoir. A dam is built inside an abandoned open-pit mine to divide the hot water reservoir into two reservoirs, a hotter reservoir and a colder reservoir. During the heating process, the water in the colder reservoir enters the hotter reservoir after being heated. Hot water is taken directly from the hotter reservoir. After being heated for users, the water temperature drops and enters the colder reservoir.

8. The energy storage system based on the transformation of an abandoned open-pit mine according to claim 7 is characterized in that: An underground pumped storage lower reservoir, an underground pumped storage upper reservoir and an underground pumped storage plant are set up to form an underground pumped storage and heat storage comprehensive energy storage system; the underground pumped storage lower reservoir is formed by placing a spherical or cylindrical precast concrete water tank at the bottom of an abandoned open-pit mine; the underground pumped storage plant is set at the bottom of the underground pumped storage lower reservoir.

9. The energy storage system based on the transformation of an abandoned open-pit mine according to claim 8, characterized in that: An underground pumped-storage lower reservoir is built at the bottom of the abandoned open-pit mine, separated from the hot water storage reservoir built above the abandoned open-pit mine; the pumped-storage lower reservoir is used for pumped storage and power generation, and the water in the hot water storage reservoir is used for heat storage after being heated and insulated.

10. The energy storage system based on the transformation of an abandoned open-pit mine according to claim 8, characterized in that: A water-isolating dam is built above the covering soil layer to form an underground pumped storage upper reservoir and a hot water storage reservoir respectively. The ventilation shaft passes through the concrete bearing layer, the covering soil layer, the water-isolating dam and is connected to the underground pumped storage reservoir.

Images