Compressed air energy storage and water pumping energy storage combined energy storage power generation system

Abstract

The invention relates to the technical field of water pumping energy storage, in particular to a compressed air energy storage and water pumping energy storage combined energy storage power generation system which comprises a high-point reservoir, a water pumping generator set and a low-point reservoir which are sequentially communicated from high to low. The high-point reservoir naturally stores water; water in the high-point reservoir can downwards flow into the hydroelectric generating set for power generation according to gravity; water flowing through the hydroelectric generating set for power generation can flow into the low-point reservoir according to gravity; the water pumping unit can pump water in the low-point reservoir into the high-point reservoir; the device further comprises a plurality of water-gas co-containing tanks. Water and air are contained in the water-air co-containing tank at the same time; the altitude of the water-gas co-containing tank is the same as that of the water pumping generator set; the water-gas co-containing tank is communicated with the high-point reservoir and the water pumping generator set simultaneously; water in the high-point reservoir can downwards flow into the water-gas co-containing tank according to gravity and compress air in the water-gas co-containing tank; and water in the water-gas co-containing tank can flow into the hydroelectric generating set under the extrusion of the compressed air to generate power.

Description

Technical Field

[0001] The present invention relates to the technical field of pumped storage, and in particular to an energy storage power generation system combining compressed air energy storage with pumped storage. Background Art

[0002] As the capacity of my country's power grid continues to grow, the difference between peak and valley power continues to increase. Some power grids have had to take compulsory power outages due to the shortage of peak power supply. This not only hinders the development of productivity, but also may bring social problems. Therefore, the introduction of energy storage systems in the power grid is an urgent need to achieve peak load regulation. In addition, with the vigorous development of renewable energy, distributed energy supply and smart grids, the actual demand for large-scale development of the energy storage industry is also increasing.

[0003] Conventional energy storage technologies mainly include flywheel energy storage, battery energy storage, superconducting energy storage, supercapacitor energy storage, pumped storage and compressed air energy storage. However, energy storage technologies that can output large capacity for several hours at a relatively low cost mainly include battery energy storage, pumped storage and compressed air energy storage. Battery energy storage is difficult to promote to the field of large-scale energy storage due to its high cost, environmental pollution in production and subsequent treatment, etc. Pumped storage, as the most mature large-scale energy storage application technology, has the advantages of high efficiency, large energy storage capacity, and mature equipment technology, but at the same time it is limited by the difficulty of site selection for reservoirs, which hinders its large-scale promotion and application. Compressed air energy storage stores energy in the form of air internal energy, but traditional compressed air energy storage technology requires underground salt caverns as gas storage space, which also has the problem of difficult site selection. Summary of the invention

[0004] In view of this, the present invention provides an energy storage power generation system combining compressed air energy storage and pumped energy storage, aiming to combine the two energy storage technologies of pumped energy storage and compressed air energy storage to generate electricity and increase the energy storage capacity. At the same time, the site selection of the entire system is easier.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A storage power generation system combining compressed air energy storage with pumped water energy storage, comprising a high-point reservoir, a pumped generator set and a low-point reservoir connected in sequence from high to low in terms of altitude; the high-point reservoir naturally stores water; the pumped generator set comprises a pumping unit and a hydroelectric generator set; water in the high-point reservoir can flow downward into the hydroelectric generator set by gravity to generate electricity; water after flowing through the hydroelectric generator set for generating electricity can flow into the low-point reservoir by gravity; the pumping unit can pump water in the low-point reservoir to the high-point reservoir; further comprising a plurality of water-gas co-containment tanks; the water-gas co-containment tanks contain both water and air; the altitude of the water-gas co-containment tank is the same as the altitude of the pumped generator set; the water-gas co-containment tank is connected to the high-point reservoir and the pumped generator set at the same time; the water in the high-point reservoir can flow downward into the water-gas co-containment tank by gravity and compress the air therein; the water in the water-gas co-containment tank can flow into the hydroelectric generator set under the compression of compressed air to generate electricity.

[0007] In some optional embodiments, the water-gas co-containment tank has a pressure piston platen and a spring; the pressure piston platen is connected to the top of the water-gas co-containment tank through the spring, and the pressure piston platen and the water-gas co-containment tank are connected in a sliding seal.

[0008] In some optional embodiments, a large-capacity water tank is further included; the altitude of the large-capacity water tank is higher than the altitude of the pumped generator set and lower than the altitude of the high-point reservoir; the large-capacity water tank is connected to the water-gas co-containment tank and the low-point reservoir at the same time; the water in the large-capacity water tank can flow downward into the water-gas co-containment tank by gravity; the low-point reservoir can pump the water therein into the large-capacity water tank.

[0009] In some optional embodiments, the altitude of the large-capacity water tank is at least 100 meters higher than the altitude of the water-gas co-containment tank.

[0010] In some optional embodiments, the volume ratio of air to water in the water-gas co-containment tank is ≥2:1 when it is in a pressure-free state.

[0011] In some optional embodiments, the altitude of the high-point reservoir is at least 1,000 meters higher than the altitude of the pumped-generator set.

[0012] In some optional embodiments, the altitude of the low-point reservoir is at least 20 meters lower than the altitude of the pumped generator set.

[0013] In summary, compared with the prior art, the present invention has the following advantages and beneficial effects: the present invention can realize hydroelectric power generation, compressed air energy storage and pumped water energy storage through the above-mentioned structure. The high water level potential energy in the high point reservoir can not only be used for hydroelectric power generation by the pumping generator set, but also, the system does not use a compressor to compress the air, but uses the high water level potential energy in the high point reservoir to compress the air in the water-gas co-containment tank to achieve energy storage, thereby making full use of the potential energy of the high water level. Multiple water-gas co-containment tanks are connected in parallel to realize continuous and controllable water supply to the pumping generator set for power generation, solving the problems of small energy storage capacity and short power generation time in the existing energy storage power generation system. The installation of the water-gas co-containment tank is not restricted by geographical conditions, and the site selection of the entire system is relatively easy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the system layout of the present invention.

[0015] The meanings of the numbers in the figure are: high point reservoir 1, large capacity water tank 2, pumping generator set 3, water-gas co-container tank 4, spring 41, pressure piston plate 42, low point reservoir 5. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0017] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0018] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there are any descriptions of "first", "second" and the like, they are only used for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0019] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0020] like Figure 1As shown, the energy storage and power generation system combining compressed air energy storage and pumped water energy storage described in the embodiment of the present application mainly includes a high-point reservoir 1, a pumped generator set 3, a low-point reservoir 5 and a plurality of water-gas co-containment tanks 4.

[0021] Among them, according to the altitude, the high-point reservoir 1 is located at the highest point of the entire system, the low-point reservoir 5 is located at the lowest point, the pumped generator set 3 and the water-gas co-containment tank 4 have the same altitude and are located between the high-point reservoir 1 and the low-point reservoir 5.

[0022] The Gaodian Reservoir 1 stores water naturally, which may be water from the river, rain water, melted snow water, etc.

[0023] The pumping generator set 3 comprises a pumping unit and a hydroelectric generator set.

[0024] A water diversion channel is provided between the high-point reservoir 1 and the pumped generator set 3, so that the water in the high-point reservoir 1 can flow downward into the hydroelectric generator set through the water diversion channel by gravity to generate electricity, thereby enabling the hydroelectric generator set to convert the potential energy of the high water level in the high-point reservoir 1 into electrical energy for output.

[0025] A water diversion channel is also provided between the low-point reservoir 5 and the pumped generator set 3. The altitude of the low-point reservoir 5 is at least 20 meters lower than the altitude of the pumped generator set 3, so that the water after power generation can flow into the low-point reservoir 5 through the water diversion channel by gravity and be collected.

[0026] On the other hand, the pumping unit can pump the water collected in the low-point reservoir 5 to the high-point reservoir 1 through the water diversion channel as needed to achieve the recycling of water resources.

[0027] The water-gas co-containment tank 4 contains both water and air. For example, when the water-gas co-containment tank 4 is in a pressure-free state, the volume ratio of air to water is ≥2:1. Obviously, due to density reasons, water is located in the lower part of the water-gas co-containment tank 4, and air is located in the upper part of the water-gas co-containment tank 4. The water-gas co-containment tank 4 is connected to the high-point reservoir 1 and the pumped generator set 3 through the water diversion channel. On the one hand, the water in the high-point reservoir 1 can flow downward into the water-gas co-containment tank 4 through the water diversion channel by gravity and compress the air therein, thereby converting the potential energy of the high water level in the high-point reservoir 1 into the internal energy of compressed air, and then realizing compressed air energy storage in the water-gas co-containment tank 4; on the other hand, the water in the water-gas co-containment tank 4 can flow into the hydroelectric generator set through the water diversion channel under the compression of compressed air to generate electricity.

[0028] The altitude of the high-point reservoir 1 is at least 1,000 meters higher than the altitude of the pumping generator set 3 to ensure that the water in the high-point reservoir 1 has a sufficiently large high water level potential energy to act on the pumping generator set 3 and compress the air in the water-gas co-container 4.

[0029] Each water diversion channel is equipped with corresponding valves to control the on and off.

[0030] The working principle of the embodiment of the present application is as follows:

[0031] Energy storage working condition: Open and close the corresponding valves to make the water diversion channel between the high-point reservoir 1 and the water-gas co-containment tank 4 unobstructed, and other water diversion channels are closed. The incoming water collected by the high-point reservoir 1 flows downward into the water-gas co-containment tank 4 by gravity and compresses the air therein, and uses the potential energy of its high water level to compress the gas in the water-gas co-containment tank 4 and store its energy in the gas in the water-gas co-containment tank 4.

[0032] Power generation conditions: When the power grid needs electricity, the corresponding valves are opened and closed to make the water diversion channels between the high-point reservoir 1, the pumped generator set 3, and the low-point reservoir 5 unobstructed, and other water diversion channels are closed. The incoming water collected by the high-point reservoir 1 flows downward by gravity into the hydroelectric generator set in the pumped generator set 3 to generate electricity, so that the hydroelectric generator set can convert the potential energy of the high water level in the high-point reservoir 1 into electrical energy for output. The water after power generation flows into the low-point reservoir 5 by gravity and is collected.

[0033] When the water in the high-point reservoir 1 is insufficient for power generation, the water diversion channel between one of the water-gas co-containment tanks 4 and the pumping generator set 3 can be opened. The water in the water-gas co-containment tank 4 can flow into the hydroelectric generator set in the pumping generator set 3 under the pressure of compressed air to generate electricity. When the water and pressure in the water-gas co-containment tank 4 reach the minimum power generation limit, the water diversion channel between the second water-gas co-containment tank 4 and the pumping generator set 3 can be opened to generate electricity using the second water-gas co-containment tank 4. More water-gas co-containment tanks 4 can be gradually opened according to the needs of the power grid to form ultra-long-term energy storage power generation.

[0034] Pumping conditions: When the high-point reservoir 1 is not full of water, or there is not enough water for power generation, or the current power generation exceeds the power consumption, the pumping unit in the pumping generator set 3 can pump water from the low-point reservoir 5 to the high-point reservoir 1 to ensure power generation, and at the same time convert the low water level potential energy in the low-point reservoir 5 into the high water level potential energy in the high-point reservoir 1.

[0035] The embodiment of the present application can realize hydroelectric power generation, compressed air energy storage and pumped water energy storage through the above-mentioned structure. The high water level potential energy in the high point reservoir 1 can not only be used for the pumping generator set 3 to generate hydroelectric power, but also, the system does not use a compressor to compress the air, but uses the high water level potential energy in the high point reservoir 1 to compress the air in the water-gas co-containment tank 4 to achieve energy storage, thereby making full use of the potential energy of the high water level. Multiple water-gas co-containment tanks 4 are connected in parallel, which can realize continuous and controllable water supply to the pumping generator set 3 for power generation, solving the problems of small energy storage capacity and short power generation time of the existing energy storage power generation system. The installation of the water-gas co-containment tank 4 is not restricted by geographical conditions, and the site selection of the entire system is relatively easy.

[0036] In order to further improve the capacity of compressed air energy storage, as an optional implementation, a pressure piston platen 42 and a spring 41 can also be set in the water-gas co-containment tank 4. The pressure piston platen 42 is connected to the top of the water-gas co-containment tank 4 through the spring 41, and the pressure piston platen 42 and the water-gas co-containment tank 4 are connected by a sliding seal. When the water in the high point reservoir 1 flows downward into the water-gas co-containment tank 4 through the water diversion channel by gravity and compresses the air therein, the compressed air will also press the pressure piston platen 42 upward and contract the spring 41, thereby storing part of the energy in the compressed spring 41. When power generation is required, the spring 41 rebounds and stretches and squeezes the air, and the air squeezes the water flow to the pumping generator set 3 to generate electricity. In this process, it is equivalent to using the energy released by the extension of the spring 41 and the energy released by the expansion of the air to generate electricity. In this way, the energy storage capacity of the water-gas co-containment tank 4 is greatly improved by the pressure piston platen 42 and the spring 41 when the volume of the water-gas co-containment tank 4 remains unchanged.

[0037] The system described in the embodiment of the present application may also include a large-capacity water tank 2. The altitude of the large-capacity water tank 2 is higher than the altitude of the water-gas co-containment tank 4 (and the pumping generator set 3), and lower than the altitude of the high-point reservoir 1. The large-capacity water tank 2 is connected to the water-gas co-containment tank 4 and the low-point reservoir 5 through water diversion channels. The water in the large-capacity water tank 2 can flow downward into the water-gas co-containment tank 4 by gravity, and the water then flows into the pumping generator set 3 to generate electricity, and the low-point reservoir 5 can also pump the water therein to the large-capacity water tank 2.

[0038] Generally speaking, the capacity of the high-point reservoir 1 is limited, and due to the uncertainty of upstream water or other water (sometimes there is more water, sometimes there is less water), the water in the high-point reservoir 1 may not be enough to act on the pumping generator set 3 for continuous power generation. When the water in the high-point reservoir 1 is not enough to act on the pumping generator set 3 for continuous power generation, the water in the large-capacity water tank 2 can be used to ensure that the pumping generator set 3 can generate electricity, waiting for the high-point reservoir 1 to collect enough water for the pumping generator set 3 to generate electricity. At the same time, the water in the low-point reservoir 5 can also be pumped into the large-capacity water tank 2 to restore the water storage capacity. The large-capacity water tank 2 can ensure the minimum power generation water level of the pumping generator set 3, for example, it is set at least 100 meters higher than the pumping generator set 3 to ensure that the water therein has a high water level potential energy large enough to act on the pumping generator set 3.

[0039] The water in the large-capacity water tank 2 flows downward into the water-gas co-containment tank 4 by gravity, and then flows to the hydroelectric generator set in the pumping generator set 3 through the water-gas co-containment tank 4 to generate electricity. The large-capacity water tank 2 mainly has the following two functions: First, it plays a role in stabilizing pressure in the entire system. The large-capacity water tank 2 has a large water storage capacity. It uses the inherent water flow inertia of the fluid to rectify the turbulent flow in the large-capacity water tank 2, the water diversion channel and the system into a laminar flow or a steady state, thereby playing a role in stabilizing pressure; second, the large-capacity water tank 2 stores a sufficient amount of water to ensure the minimum power generation water level of the pumping generator set 3, and ensure that there is a certain amount of water flow to fill the water generator set 3 at the lowest water level, preventing gas from flowing in to cause water-gas mixing or the "water hammer" phenomenon, which greatly improves the stability of the system. In general, the large-capacity water tank 2 plays the role of water storage and water flow rectification in the entire energy storage power generation system, while preventing other inflows from harming the unit, solving the problem of unstable power generation of the pumping generator set 3.

[0040] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0041] The above preferred embodiments shall not be regarded as limiting the present invention, and the protection scope of the present invention shall be subject to the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications shall also be regarded as the protection scope of the present invention.

Claims

1. An energy storage power generation system combining compressed air energy storage and pumped water energy storage, characterized in that: It includes a high-point reservoir (1), a pumped generator set (3) and a low-point reservoir (5) which are connected in order from high to low in terms of altitude; The high point reservoir (1) stores water naturally; The pumping generator set (3) comprises a pumping unit and a hydroelectric generator set; The water in the high-point reservoir (1) can flow downward into the hydroelectric generator set by gravity to generate electricity; the water after flowing through the hydroelectric generator set to generate electricity can flow into the low-point reservoir (5) by gravity; The pumping unit is capable of pumping water in the low-point reservoir (5) to the high-point reservoir (1); It also includes a plurality of water-gas co-containment tanks (4); the water-gas co-containment tanks (4) contain water and air at the same time; the altitude of the water-gas co-containment tanks (4) is the same as the altitude of the pumping generator set (3); the water-gas co-containment tanks (4) are connected to the high point reservoir (1) and the pumping generator set (3) at the same time; The water in the high-point reservoir (1) can flow downward into the water-gas co-containment tank (4) by gravity and compress the air therein; the water in the water-gas co-containment tank (4) can flow into the hydroelectric generator set under the pressure of compressed air to generate electricity.

2. The energy storage power generation system combining compressed air energy storage and pumped water energy storage as claimed in claim 1, characterized in that: The water-gas co-containment tank (4) has a pressure piston platen (42) and a spring (41) therein; the pressure piston platen (42) is connected to the top of the water-gas co-containment tank (4) via the spring (41), and the pressure piston platen (42) and the water-gas co-containment tank (4) are connected in a sliding and sealing manner.

3. The energy storage power generation system combining compressed air energy storage and pumped water energy storage as claimed in claim 1 or 2, characterized in that: Also includes a large capacity water tank (2); The altitude of the large-capacity water tank (2) is higher than the altitude of the pumped-water generator set (3) and lower than the altitude of the high-point reservoir (1); The large-capacity water tank (2) is connected to the water-gas co-containment tank (4) and the low-point water reservoir (5) at the same time; the water in the large-capacity water tank (2) can flow downward into the water-gas co-containment tank (4) by gravity; and the low-point water reservoir (5) can pump the water therein into the large-capacity water tank (2).

4. The energy storage power generation system combining compressed air energy storage and pumped water energy storage as claimed in claim 3, characterized in that: The altitude of the large-capacity water tank (2) is at least 100 meters higher than the altitude of the water-gas co-container tank (4).

5. The energy storage power generation system combining compressed air energy storage and pumped water energy storage as claimed in claim 1, characterized in that: When the water-gas co-container tank (4) is in a pressure-free state, the volume ratio of air to water therein is ≥2:

1.

6. The energy storage power generation system combining compressed air energy storage and pumped water energy storage as claimed in claim 1, characterized in that: The altitude of the high-point reservoir (1) is at least 1,000 meters higher than the altitude of the pumped generator set (3).

7. The energy storage power generation system combining compressed air energy storage and pumped water energy storage as claimed in claim 1, characterized in that: The altitude of the low-point reservoir (5) is at least 20 meters lower than the altitude of the pumped generator set (3).

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