Composite power station based on underground compressed air reservoir

Abstract

The composite power station comprises a compressed air energy storage unit and a gravity energy storage unit, the compressed air energy storage unit comprises ground plant equipment, an underground air storage cavern, an air conveying pipeline, a vertical shaft and an inclined shaft, the underground air storage cavern is provided with a closed air storage cavity, and the air conveying pipeline is connected with the underground air storage cavern and the ground plant equipment; one ends of the vertical shaft and the inclined shaft are respectively communicated with the ground, and the other ends respectively extend to the side surface of the underground gas storage cavern; the gravity energy storage unit comprises a weight and a hoisting device, the weight is arranged in the vertical shaft and / or the inclined shaft, and the hoisting device is configured to drive the weight to move in the length direction of the vertical shaft and / or the inclined shaft so as to convert gravitational potential energy and electric energy; according to the composite power station based on the underground compressed air storage cavern, the gravity energy storage power station is built by reusing the underground air storage cavern, the construction cost of a gravity channel is saved while the blocking work amount is reduced, and the ground space is saved.

Description

Technical Field

[0001] This application relates to the technical field of gravity energy storage, and particularly to a composite power station based on an underground compressed air storage reservoir. Background Art

[0002] Energy storage technology is an effective way to solve the problems of intermittency and instability of renewable energy sources such as wind power and solar energy, and to ensure the safe and stable operation of the power system. With the increasing proportion of new energy in the power system in China, the demand for energy storage is also rising. Compressed air energy storage and gravity energy storage both belong to physical energy storage. They have simple technical principles, can be built on a large scale, and have certain economic viability, making them relatively popular grid energy storage technologies at present. Among them, the principle of compressed air energy storage is to convert electrical energy into the internal energy and potential energy of compressed air, which requires large-scale gas storage devices, usually using underground chambers with a volume generally above 100,000 cubic meters. Such gas storage chambers have a certain burial depth. When considering construction during the construction of the chambers, vertical shafts / inclined shafts need to be excavated first to reach the target burial depth, and then the gas storage chambers are built. After the gas storage chambers are constructed later, for safety reasons, the vertical shafts / inclined shafts will be left empty and subjected to certain plugging treatments, which to some extent wastes underground space resources and increases the amount of engineering work. Utility Model Content

[0003] An embodiment of this application provides a composite power station based on an underground compressed air storage reservoir. This composite power station based on an underground compressed air storage reservoir constructs a gravity energy storage power station by reusing the underground gas storage chamber, reducing the amount of plugging work and eliminating the construction cost of the gravity channel, and saving ground space.

[0004] The composite power station based on an underground compressed air storage reservoir provided by an embodiment of this application includes:

[0005] A compressed air energy storage unit, the compressed air energy storage unit includes ground plant equipment, an underground gas storage chamber, a gas transmission pipeline, a vertical shaft, and an inclined shaft. The underground gas storage chamber has a closed gas storage cavity. The gas transmission pipeline connects the underground gas storage chamber and the ground plant equipment. One end of the vertical shaft and the inclined shaft is respectively connected to the ground, and the other end respectively extends to the side of the underground gas storage chamber;

[0006] A gravity energy storage unit, the gravity energy storage unit includes a heavy object and a hoisting device. The heavy object is arranged in the vertical shaft and / or the inclined shaft, and the hoisting device is configured to drive the heavy object to move along the length direction of the vertical shaft and / or the inclined shaft to perform the conversion between gravitational potential energy and electrical energy.

[0007] In addition, the composite power station based on an underground compressed air storage reservoir provided by an embodiment of this application may also have the following additional technical features:

[0008] In an alternative solution, the heavy objects are respectively arranged in the vertical shaft and the inclined shaft. The number of the hoisting devices is at least two. At least two hoisting devices are respectively connected to the heavy objects located in the vertical shaft and the inclined shaft through slings. A slide rail is arranged on the side wall of the inclined shaft.

[0009] In an alternative solution, the underground gas storage cavern is sealed by a plugging body. The inner wall of the underground gas storage cavern is provided with a sealing material, a lining and a support measure. A valve for controlling the gas flow rate and a switch for controlling the inlet and outlet of gas are arranged on the gas transmission pipeline.

[0010] In an alternative solution, the plugging body is formed by backfilling with a concrete layer. At least one layer of steel mesh is arranged in the concrete layer. The outer wall of the gas transmission pipeline is closely attached to and sealed with the concrete layer.

[0011] In an alternative solution, the vertical shaft is a circular shaft, and the diameter of the vertical shaft is 6 - 14 m. The cross-section of the inclined shaft is in the shape of a horseshoe arch. The heavy objects are stones or iron blocks.

[0012] The beneficial effects of the embodiments of the present application are as follows:

[0013] This composite power station based on an underground compressed air storage uses the vertical shaft / inclined shaft of the compressed air storage cavern to construct gravity energy storage, eliminating the plugging work volume. At the same time, it also realizes the reuse of idle space resources, saving the ground land use and construction cost of gravity energy storage. In addition, gravity energy storage can also increase a certain economic benefit on the basis of the original power station.

[0014] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the composite power station based on an underground compressed air storage provided by the present application.

[0016] Reference numerals: ground plant equipment 1, underground gas storage cavern 2, plugging body 3, vertical shaft 4, inclined shaft 5, gas transmission pipeline 6, hoisting device 7, sling 8, heavy object 9, slide rail 10.

[0017] The drawings here are incorporated into the specification and form a part of the specification, showing the embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] In order to better understand the technical solution of the present application, the embodiments of the present application will be described in detail below with reference to the drawings.

[0019] It should be clear that the described embodiments are only a part of the embodiments of this application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.

[0020] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments, and are not intended to limit this application. The singular forms "a", "the" and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0021] It should be understood that the term "and / or" used herein is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0022] It should be noted that the orientation terms such as "upper", "lower", "left", and "right" described in the embodiments of this application are described from the angles shown in the drawings and should not be construed as a limitation on the embodiments of this application. In addition, in the context, it should also be understood that when it is mentioned that an element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element.

[0023] As Figure 1 shown, the embodiments of this application provide a composite power station based on an underground compressed air energy storage reservoir. The composite power station based on the underground compressed air energy storage reservoir includes a compressed air energy storage unit and a gravity energy storage unit. Among them, the compressed air energy storage unit includes ground plant equipment 1, an underground gas storage chamber 2, a gas transmission pipeline 6, a vertical shaft 4, and an inclined shaft 5. The underground gas storage chamber 2 has a closed gas storage cavity. The gas transmission pipeline 6 connects the underground gas storage chamber 2 and the ground plant equipment 1. One end of the vertical shaft 4 and the inclined shaft 5 is respectively connected to the ground, and the other end extends to the side of the underground gas storage chamber 2; the gravity energy storage unit includes a heavy object 9 and a hoisting device 7. The heavy object 9 is arranged in the vertical shaft 4 and / or the inclined shaft 5. The hoisting device 7 is configured to drive the heavy object 9 to move along the length direction of the vertical shaft 4 and / or the inclined shaft 5 to perform the conversion of gravitational potential energy and electric energy. The gravity energy storage unit relies on the construction of a compressed air energy storage power station to form a composite power station. The compressed air energy storage unit and the gravity energy storage unit share the underground vertical shaft 4 / inclined shaft 5, and can also share the ground plant and the conveying system.

[0024] The composite power station based on the underground compressed air storage uses the vertical shaft 4 / inclined shaft 5 of the compressed air storage chamber to construct gravity energy storage, eliminating the need for plugging work, realizing the reuse of idle space resources, saving the ground land use and construction costs of gravity energy storage. In addition, gravity energy storage can also increase certain economic benefits on the basis of the original power station.

[0025] As Figure 1 shown, in a specific embodiment, heavy objects 9 are respectively arranged in the vertical shaft 4 and the inclined shaft 5. The number of hoisting devices 7 is at least two. At least two hoisting devices 7 are respectively connected to the heavy objects 9 located in the vertical shaft 4 and the inclined shaft 5 through slings 8. A slide rail 10 is arranged on the side wall of the inclined shaft 5.

[0026] Specifically, the vertical shaft 4 is suitable for the hoisting type, and the heavy object 9 is vertically lifted and lowered through the ground hoisting device 7 and the sling 8, so as to store energy and generate electricity. The inclined shaft 5 is suitable for the slope type, and energy storage and power generation are carried out through the ground hoisting device 7, the track and the heavy object 9.

[0027] The scale of gravity energy storage is determined by the mass of the heavy object 9 and the buried depth of the chamber. According to the gravitational potential energy formula E = mgh, the mass m of the heavy object 9 here is determined by density and volume. The heavy object 9 can be a stone or an iron block, and the greater the density, the more beneficial it is to energy storage; the cross section of the heavy object 9 is controlled by the cross section of the vertical shaft 4 / inclined shaft 5, and the maximum height of a single heavy object 9 is determined by the performance of the hoisting device 7. The buried depth h is determined by the gas storage chamber. Considering factors such as anti-lifting stability, rock mass, and regional structure, the general buried depth is 80 - 250m. For the gas storage chamber transformed from an abandoned mine, the buried depth can exceed 500m. The installed capacity of gravity energy storage is obtained by multiplying the gravitational potential energy by the conversion efficiency W = Eη. The conversion efficiency η is generally 80% - 90% according to the performance and losses of the unit.

[0028] As Figure 1 shown, in a specific embodiment, the underground gas storage chamber 2 is blocked by a blocking body 3. The inner wall of the underground gas storage chamber 2 is provided with sealing materials, lining and support measures, which can meet the sealing and stability requirements during the storage and release of high-pressure gas. A valve for controlling the gas flow and a switch for controlling the inlet and outlet of gas are arranged on the gas transmission pipeline 6.

[0029] As Figure 1 shown, in a specific embodiment, the blocking body 3 is formed by backfilling with a concrete layer. At least one layer of steel mesh is arranged in the concrete layer. The outer wall of the gas transmission pipeline 6 is closely attached to and sealed with the concrete layer, that is, when backfilling, the pipe wall of the gas transmission pipe is closely attached to the blocking body 3 to ensure no leakage.

[0030] In addition, the vertical shaft 4 is circular with a diameter ranging from 6 to 14 m. It is used for transportation, ventilation, etc. during the construction of the preliminary chamber. After the chamber is sealed, it forms an independent space connected to the ground. Support measures have been taken during the excavation of the vertical shaft 4 to ensure stability. Support measures have also been taken during the excavation of the inclined shaft 5 to maintain the structural stability. The inclined shaft 5 is used as a maintenance passage in the later stage, and the gas transmission pipeline 6 reaches the ground along the wall of the inclined shaft 5. The cross-section of the inclined shaft 5 is in the shape of a horseshoe arch, with a flat bottom. During the construction of the gas storage chamber, a slide rail 10 can be arranged for slag transportation. Later, the slide rail 10 is reused for the transportation of heavy objects by gravity.

[0031] Embodiment 1: A power station combining compressed air energy storage and gravity energy storage is to be built in a certain area in the northwest, mainly a compressed air energy storage power station. The buried depth of the underground compressed air gas storage is selected at 150 m. A vertical shaft and an inclined shaft are respectively arranged. The diameter of the vertical shaft is 6 m, and the inclined shaft has a horseshoe-shaped cross-section of 8×12. Now, the design of the gravity energy storage installed capacity is carried out.

[0032] The heavy object is made of iron block with a density of 7.8 g / cm 3 . Among them, according to the shape of the vertical shaft, the heavy object in the vertical shaft is in the shape of a cylinder, with dimensions slightly smaller than the vertical shaft. The designed diameter of the heavy object is 5.6 m and the height is 20 m. The center of gravity of the heavy object can move 135 m. According to the potential energy calculation formula E = ρh2πr 2 gh1, considering the conversion efficiency of the vertical shaft gravity energy storage is 85%, the installed capacity W of the vertical shaft gravity energy storage is about 1.18 MWh.

[0033] The cubic blocks are used in the inclined shaft section with dimensions of 6 m×8 m×20 m. Considering that there is no stacking area in the inclined shaft and only one heavy object is stored, the change distance of the center of gravity of the heavy object is 130 m. Then the potential energy E that can be stored max = ρgh1abc. Considering the conversion efficiency under the action of the track is 80%, the installed capacity of the inclined shaft is 2.12 MMWh. When using the vertical shaft and the inclined shaft for gravity energy storage, an additional installed capacity of 3.3 MWh can be obtained. And in the case of considering multiple heavy object blocks, the installed capacity can be further increased and can easily reach 10 MWh. Calculated according to the power generation duration of 1 hour, the installed capacity is 3.3 MW, and multiple charge and discharge operations can be carried out every day. The gravity energy storage and the compressed air energy storage can operate independently, and the charge and discharge are used for different purposes. The gravity energy storage motor can be direct current and can be directly used to meet the daily power consumption needs of nearby projects. Thus, it can be seen that the composite power station based on the underground compressed air storage in the embodiment of the present application can achieve the expected technical effects in practical applications.

[0034] The above is only the preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A composite power plant based on an underground compressed air storage, characterized in that: include: A compressed gas energy storage unit, the compressed gas energy storage unit comprising ground plant equipment, an underground gas storage cavern, a gas transmission pipeline, a vertical shaft and an inclined shaft, the underground gas storage cavern having a closed gas storage cavity, the gas transmission pipeline connecting the underground gas storage cavern and the ground plant equipment, one end of the vertical shaft and the inclined shaft are respectively connected to the ground, and the other ends extend to the side of the underground gas storage cavern; A gravity energy storage unit, wherein the gravity energy storage unit comprises a weight and a lifting device, wherein the weight is arranged in the vertical shaft and / or the inclined shaft, and the lifting device is configured to drive the weight to move along the length direction of the vertical shaft and / or the inclined shaft to convert gravitational potential energy and electrical energy.

2. The composite power plant based on underground compressed air storage according to claim 1 is characterized in that: The weights are respectively arranged in the vertical shaft and the inclined shaft, the number of the lifting devices is at least two, at least two of the lifting devices are respectively connected to the weights located in the vertical shaft and the inclined shaft through lifting devices, and the side walls of the inclined shaft are provided with slide rails.

3. The composite power plant based on underground compressed air storage according to claim 1 or 2, characterized in that: The underground gas storage cavern is sealed by a sealing body, the inner wall of the underground gas storage cavern is provided with sealing materials, lining and supporting measures, and the gas transmission pipeline is provided with a valve for controlling the gas flow and a switch for controlling the inlet and outlet of gas.

4. The composite power plant based on underground compressed air storage according to claim 3 is characterized in that: The blocking body is formed by backfilling a concrete layer, at least one layer of steel mesh is arranged in the concrete layer, and the outer wall of the gas pipeline is tightly attached to and sealed with the concrete layer.

5. The composite power plant based on underground compressed air storage according to claim 1, 2 or 4, characterized in that: The vertical shaft is a circular shaft, and the diameter of the vertical shaft is 6 to 14 meters. The cross-section of the inclined shaft is a city gate tunnel type, and the heavy object is a stone or an iron block.

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