Isothermal compressed air energy storage device

Abstract

The utility model provides an isothermal compressed air energy storage device, which belongs to the technical field of compressed air energy storage and is characterized in that a solid heat exchange medium is arranged in a cylinder body of a compression cylinder, the solid heat exchange medium is in the shape of a cylinder with a hollow top, and a cylindrical hole at the upper end of a hollow part is matched with a plunger; the outer wall of the cylindrical solid heat exchange medium is fixed to the inner wall of the compression cylinder body, one part of the solid heat exchange medium is immersed in the liquid heat exchange medium, and the other part of the solid heat exchange medium makes contact with air in the compression cylinder body. On the basis that a solid heat exchange medium is introduced to improve the transfer rate of compression heat from air to a liquid heat exchange medium, the solid heat exchange medium is fixed on the side wall of the cylinder body of the compression cylinder, one part of the solid heat exchange medium is in contact with the air, and the other part of the solid heat exchange medium is in contact with the liquid heat exchange medium; while heat exchange is enhanced, fluid resistance of a solid heat exchange medium and a liquid heat exchange medium is avoided, compression work is reduced, and energy storage efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to compressed air energy storage technology field, concretely relates to a kind of isothermal compressed air energy storage device. BACKGROUND

[0002] With the global attention to renewable energy, the use of renewable energy such as wind energy and solar energy is increasing. The volatility of these energy sources makes the power system need effective energy storage technology to balance supply and demand.

[0003] Compressed air energy storage is an effective means to solve the large-scale, long-term storage problem of renewable energy. Isothermal compressed air energy storage technology uses special heat transfer technology to make the temperature change small during air compression, realizing near-isothermal compression process. Because the temperature is almost unchanged during compression, the compression work can be reduced, thereby improving system efficiency. However, different isothermal compression technologies currently have certain problems, for example, in the water foam technology, although the water foam can increase the heat transfer performance of the system, but after multiple cycles, the accumulation of residual foam will change the heat transfer characteristics and fluid dynamics characteristics inside the system; in the liquid spray technology, although the smaller the diameter of the spray droplets, the better the heat transfer effect of the system, but it will also increase the power consumption of the circulating pump.

[0004] In view of this, some scholars have proposed an isothermal compression method using liquid medium heat transfer and piston heat transfer. This method introduces a liquid heat transfer medium with large specific heat capacity and a solid heat transfer medium with large specific surface area based on traditional compressed air energy storage technology. In the process of compressing air, the large specific surface area of the solid heat transfer medium is used to quickly transfer the compression heat from the air to the liquid heat transfer medium, and the large specific heat capacity of the liquid heat transfer medium is used to ensure that the system temperature does not change much after absorbing the compression heat, thereby realizing near-isothermal compression and improving system efficiency. However, the above compression method using solid heat transfer medium and fixed piston will introduce fluid resistance between the solid heat transfer medium and the liquid heat transfer medium, which will reduce the energy storage efficiency of the system. SUMMARY

[0005] To make up for the above shortcomings, the utility model provides an isothermal compressed air energy storage device that improves the transfer rate of compression heat from air to liquid heat transfer medium while eliminating fluid resistance between solid heat transfer medium and liquid heat transfer medium, reducing compression work and improving energy storage efficiency.

[0006] The utility model is implemented as follows:

[0007] The application relates to an isothermal compressed air energy storage device, which comprises a compression cylinder body, a plunger arranged at the upper end of the cylinder body, a driving mechanism arranged on the plunger, a liquid heat exchange medium arranged in the compression cylinder body, a water circulation heat exchange mechanism arranged at the lower end of the compression cylinder body, and a gas storage device connected to the upper end of the compression cylinder body through a pipeline, characterized in that a solid heat exchange medium is arranged in the compression cylinder body, the solid heat exchange medium is in the shape of a hollow cylinder with a top, a cylindrical hole at the upper end of the hollow part is matched with the plunger, the outer wall of the cylindrical solid heat exchange medium is fixed on the inner wall of the compression cylinder body, and a part of the solid heat exchange medium is immersed in the liquid heat exchange medium, and another part of the solid heat exchange medium is in contact with air in the compression cylinder body.

[0008] In addition, the isothermal compressed air energy storage device provided by the technical scheme has the following additional technical features.

[0009] In the technical scheme, the solid heat exchange medium is in at least one of a porous structure, a mesh structure, a wire structure, a tubular structure and a fin structure.

[0010] In the technical scheme, the water circulation heat exchange mechanism comprises a liquid circulation inlet, a liquid circulation outlet and a heat exchange device, the bottom of the compression cylinder body is respectively provided with the liquid circulation inlet and the liquid circulation outlet, the heat exchange device is communicated with the compression cylinder body through a circulating pump, and the heat exchange device, the compression cylinder body and the circulating pump are connected in series to form a water circulation heat exchange loop.

[0011] In the technical scheme, an air inlet and an air outlet are arranged on the side surface of the compression cylinder body, the air outlet is connected with the gas storage device through a gas-liquid separation device, and the bottom of the gas-liquid separation device is connected with the water circulation heat exchange loop.

[0012] In the technical scheme, the driving mechanism comprises a crank connecting rod and a driving piece, one end of the crank connecting rod is connected with the plunger, and the other end of the crank connecting rod is connected with the driving piece.

[0013] In the technical scheme, a compression cylinder cover is arranged on the top of the compression cylinder body, a through hole is arranged on the compression cylinder cover, a limiting ring is arranged on the compression cylinder cover and extends downward along the inner diameter of the through hole, and the plunger is slidingly connected with the limiting ring.

[0014] Compared with the prior art, the isothermal compressed air energy storage device has the following beneficial effects:

[0015] The utility model discloses a solid heat exchange medium is introduced, improve the rate of compressed heat transmission from air to liquid heat exchange medium, and, through fixing solid heat exchange medium on the lateral wall of compression cylinder cylinder body, part of solid heat exchange medium contacts air, and another part contacts liquid heat exchange medium, and the purpose is if solid heat exchange medium is all immersed in liquid heat exchange medium, liquid heat exchange medium needs to have flow, and all immersion will influence flow effect, therefore, solid heat exchange medium is immersed in part of liquid heat exchange medium, like this, it is strengthened heat exchange simultaneously, and the fluid resistance of solid heat exchange medium and liquid heat exchange medium is avoided, using water circulation heat exchange mechanism makes liquid heat exchange medium always be in the characteristic of big specific heat capacity, and then can realize isothermal compression, reduce compression work, increase energy storage efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will be to the drawing needed in the embodiment used briefly introduce, it should be understood, the following drawings only shows some embodiments of the utility model, therefore should not be regarded as the limitation to the scope, for ordinary skilled person in the art comes, under the premise of not paying creative labor, can also obtain other related drawings according to these drawings.

[0017] Figure 1 It is the overall structure schematic diagram of the utility model isothermal compression air energy storage device;

[0018] Figure 2 It is the three-dimensional perspective view of the utility model isothermal compression air energy storage device;

[0019] Figure 3 Fig. (a) is the longitudinal section structure schematic diagram of solid heat exchange medium in the utility model, Fig. (b) is the cross section structure schematic diagram of solid heat exchange medium in the utility model, Fig. (c) is the three-dimensional perspective view of solid heat exchange medium in the utility model;

[0020] Figure 4 Fig. (a) is the three-dimensional perspective view of compression cylinder cylinder cover in the utility model, Fig. (d) is the cooperation three-dimensional perspective view of compression cylinder cylinder body and compression cylinder cylinder cover in the utility model.

[0021] Fig. 1, crank connecting rod part;2, driving part;3, plunger;4, compression cylinder cylinder cover;5, solid heat exchange medium;6, exhaust port;7, air inlet;8, air containing cavity;9, liquid heat exchange medium;10, compression cylinder cylinder body;11, liquid circulation outlet;12, liquid circulation inlet;13, heat exchange device;14, circulating pump;15, gas storage device;16, gas-liquid separation device. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] In previous technologies, the solid heat exchange medium 5 was placed at the lower end of the plunger 3, forming a compression method in which the solid heat exchange medium 5 and the plunger 3 were coupled. That is, when the plunger 3 was pressed down, the solid heat exchange medium 5 was also pressed down to the liquid surface of the liquid heat exchange medium 9. This increased the flow resistance of the liquid heat exchange medium 9. Therefore, in this application, the solid heat exchange medium 5 is set as a hollow cylindrical shape. The outer wall of the solid heat exchange medium 5 is fixed to the inner wall of the compression cylinder body 10. The size of the hollow part of the solid heat exchange medium 5 matches the size of the plunger 3, thereby allowing the plunger 3 to move up and down. Thus, during the up and down movement of the plunger 3, the solid heat exchange medium 5 will not be pressed into the liquid heat exchange medium 9, reducing the flow resistance of the liquid heat exchange medium 9. Furthermore, part of the solid heat exchange medium 5 is in contact with the air, and the other part is in contact with the liquid heat exchange medium 9, which improves the rate of heat transfer from the air to the liquid heat exchange medium 9, reduces the compression work, and increases the energy storage efficiency.

[0024] An isothermal compressed air energy storage device, such as Figure 1 As shown, the device includes a compression cylinder body 10 and a plunger 3 disposed at the upper end of the cylinder body. A driving mechanism is disposed on the plunger 3. A liquid heat exchange medium 9 is disposed inside the compression cylinder body 10. A water circulation heat exchange mechanism is disposed at the lower end of the compression cylinder body 10. The upper end of the compression cylinder body 10 is connected to an air storage device 15 through a pipeline. An air receiving cavity 8 is located between the compression cylinder body 10 and the plunger 3 for storing air. A solid heat exchange medium 5 is disposed inside the compression cylinder body 10. The solid heat exchange medium 5 is shaped as a hollow cylindrical tube with a cylindrical hole at the upper end of the hollow part matching the plunger 3. The outer wall of the cylindrical solid heat exchange medium 5 is fixed to the inner wall of the compression cylinder body 10. Part of the solid heat exchange medium 5 is immersed in the liquid heat exchange medium 9, and the other part is in contact with the air inside the compression cylinder body 10.

[0025] In this way, the solid heat exchange medium 5 is introduced, and the rate of the compression heat transferred from the air to the liquid heat exchange medium 9 is improved; and by fixing the solid heat exchange medium 5 on the side wall of the compression cylinder body 10, part of the solid heat exchange medium 5 is in contact with the air, and part of the solid heat exchange medium 5 is in contact with the liquid heat exchange medium 9, and the purpose is that if the solid heat exchange medium 5 is completely immersed in the liquid heat exchange medium 9, the liquid heat exchange medium 9 needs to have fluidity, and the complete immersion will affect the flow effect, and therefore, the solid heat exchange medium 5 is partially immersed in the liquid heat exchange medium 9, so that the heat exchange is enhanced, and the fluid resistance of the solid heat exchange medium 5 and the liquid heat exchange medium 9 is avoided, the water circulation heat exchange mechanism is utilized, the liquid heat exchange medium 9 is always in the characteristics of large specific heat capacity, and then the isothermal compression can be realized, the compression work is reduced, and the energy storage efficiency is increased.

[0026] In the embodiment of the utility model, as shown in Figure 3 The material of the solid heat exchange medium 5 is metal, and the structure of the solid heat exchange medium 5 is at least one of a porous structure, a mesh structure, a wire structure, a tubular structure and a fin structure; in this way, the solid heat exchange medium 5 has a large specific surface area and strong heat exchange capacity; for example, the material of the solid heat exchange medium 5 is copper, and copper has good heat conductivity and low cost.

[0027] It should be noted that the lower dead point of the stroke of the plunger 3 and the upper surface of the liquid heat exchange medium 9 have a certain distance.

[0028] In the embodiment of the utility model, as shown in Figure 1 The water circulation heat exchange mechanism comprises a liquid circulation inlet 12, a liquid circulation outlet 11 and a heat exchange device 13, the bottom of the compression cylinder body 10 is respectively provided with the liquid circulation inlet 12 and the liquid circulation outlet 11, the heat exchange device 13 is communicated with the compression cylinder body 10 through a circulating pump 14, and the heat exchange device 13, the compression cylinder body 10 and the circulating pump 14 are connected in series to form a water circulation heat exchange loop; in this way, when the liquid heat exchange medium 9 in the compression cylinder body 10 reaches a pre-set temperature, the circulating pump 14 is opened to make the liquid heat exchange medium 9 flow from the liquid circulation outlet 11 into the heat exchange device 13 for heat exchange, after the heat exchange is completed, the temperature of the liquid heat exchange medium 9 is reduced, and finally flows back into the compression cylinder body 10 from the liquid circulation inlet 12 under the action of the circulating pump 14, so that the temperature of the liquid heat exchange medium 9 is always kept in an isothermal state.

[0029] In the embodiment of the utility model, as shown in Figure 1As shown, the air inlet 7 and the exhaust port 6 are arranged on the side of the compression cylinder body 10 respectively, the exhaust port 6 is connected with the gas storage device 15 through the gas-liquid separation device 16, and the bottom of the gas-liquid separation device 16 is connected with the water circulation heat exchange loop, so that when the high-pressure air passes through the exhaust port 6 and enters the gas-liquid separation device 16, the separated high-pressure air is stored in the gas storage device 15, and the separated liquid heat exchange medium 9 flows back to the compression cylinder body 10 through the heat exchange circulation loop.

[0030] In the embodiment of the utility model, as shown in Figures 1-2 As shown, the driving mechanism comprises: a crank connecting rod 1 and a driving piece 2, one end of the crank connecting rod 1 is a plunger 3, and the other end of the crank connecting rod 1 is connected with the driving piece 2; in this way, the driving piece 2 drives the crank connecting rod 1 to move, and then drives the plunger 3 to move from the lower dead point to the upper dead point, and the driving piece 2 can be a motor or other driving piece 2 capable of achieving the same function, therefore, the application is not limited here.

[0031] In the embodiment of the utility model, as shown in Figure 4 As shown, the compression cylinder cover 4 is provided with a limiting ring extending downward along the inner diameter of the through hole, and the plunger 3 is slidingly connected to the limiting ring; in this way, the limiting ring separates the solid heat exchange medium 5 and the plunger 3, preventing the plunger 3 from wearing the solid heat exchange medium 5 during the up-and-down movement, and the depth distance from the upper surface of the liquid heat exchange medium 9 has a certain distance, so that air can enter the solid heat exchange medium 5, and the cylinder cover 4 can be fixed on the compression cylinder body 10 by thread connection, welding or other methods.

[0032] In the embodiment of the utility model, as shown in Figure 1 As shown, the material of the liquid heat exchange medium 9 is at least one of water, molten salt, heat-conducting oil and refrigeration oil; preferably, the material of the liquid heat exchange medium 9 is water, which has a large specific heat capacity and is easy to obtain and clean without pollution; specifically, the height of the liquid heat exchange medium 9 is one third of the compression cylinder body 10, and the material and volume of the liquid heat exchange medium 9 can be appropriately adjusted according to the actual application scene; the application is not limited in this regard.

[0033] In the embodiment of the utility model, the type of the gas storage device 15 includes but is not limited to underground caves, artificial caverns, abandoned mines, gas storage tanks and underwater gas storage devices 15 such as lakes and oceans, preferably the gas storage device 15 is a steel gas storage tank, which has good sealing performance and can withstand a large air pressure, and has high safety.

[0034] Implementation process: when in use, the isothermal compressed air energy storage working process includes an intake stroke, a compression stroke, an exhaust stroke, and a liquid circulation process; the intake stroke: the driving member 2 drives the crank connecting rod member 1 to move, thereby driving the plunger 3 to move from the bottom dead center to the top dead center; during the intake process, the air intake port 7 is open, the air exhaust port 6 is closed, and the air is sucked into the compression cylinder body 10; the compression stroke: the driving member 2 drives the crank connecting rod member 1 to move, thereby driving the plunger 3 to move from the top dead center to the bottom dead center; during the compression process, the air intake port 7 and the air exhaust port 6 are both in a closed state, the plunger 3 is compressed quickly, the air in the air containing cavity 8 generates compression heat, the temperature of the air rises, the compression heat is finally transferred into the liquid heat exchange medium 9 through the solid heat exchange medium 5, and the temperature of the liquid heat exchange medium 9 does not change obviously after absorbing heat due to the large specific heat capacity; the exhaust stroke: when the driving member 2 drives the crank connecting rod member 1 to drive the plunger 3 to approach the bottom dead center, the air exhaust port 6 is in an open state, and the air intake port 7 is in a closed state; the high-pressure air passes through the air exhaust port 6 and enters the gas-liquid separation device 16, wherein the separated high-pressure air is stored in the air storage device 15, and the separated liquid heat exchange medium 9 finally flows back into the cylinder body 10 through the heat exchange circulation loop; the liquid circulation process: when the liquid heat exchange medium 9 in the cylinder body 10 reaches a preset temperature, the circulation pump 14 is opened, so that the liquid heat exchange medium 9 flows into the heat exchange device 13 from the liquid circulation outlet 11 to exchange heat; after the heat exchange is completed, the temperature of the liquid heat exchange medium 9 decreases, and finally flows back into the cylinder body 10 from the liquid circulation inlet 12 under the action of the circulation pump 14.

[0035] It should be noted that the specific model specifications of the driving member 2, the heat exchange device 13, the circulation pump 14 and the gas-liquid separation device 16 need to be selected and determined according to the actual specifications of the device, so they will not be described in detail.

[0036] The above is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. 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. An isothermal compressed air energy storage device, comprising a compression cylinder body (10) and a plunger (3) arranged at the upper end of the cylinder body, wherein a driving mechanism is arranged on the plunger (3), a liquid heat exchange medium (9) is arranged in the compression cylinder body (10), a water circulation heat exchange mechanism is arranged at the lower end of the compression cylinder body (10), and the upper end of the compression cylinder body (10) is connected to a gas storage device (15) through a pipeline, characterized in that, The compression cylinder body (10) is provided with a solid heat exchange medium (5), the shape of the solid heat exchange medium (5) is a hollow cylinder at the top, the cylinder hole at the upper end of the hollow part is matched with the plunger (3), the outer wall of the hollow cylinder of the solid heat exchange medium (5) is fixed on the inner wall of the compression cylinder body (10), a part of the solid heat exchange medium (5) is immersed in the liquid heat exchange medium (9), and the other part is in contact with air in the compression cylinder body (10).

2. An isothermal compressed air energy storage device according to claim 1, wherein, The solid heat exchange medium (5) is at least one of a porous structure, a reticular structure, a filament structure, a tubular structure and a fin structure.

3. An isothermal compressed air energy storage device according to claim 1, wherein, The water circulation heat exchange mechanism comprises a liquid circulation inlet (12), a liquid circulation outlet (11) and a heat exchange device (13), the bottom of the compression cylinder body (10) is respectively provided with the liquid circulation inlet (12) and the liquid circulation outlet (11), the heat exchange device (13) is communicated with the compression cylinder body (10) through a circulating pump (14), and the heat exchange device (13), the compression cylinder body (10) and the circulating pump (14) are connected in series to form a water circulation heat exchange loop.

4. An isothermal compressed air energy storage device according to claim 3, wherein, An air inlet (7) and an exhaust port (6) are arranged on the side of the compression cylinder body (10), the exhaust port (6) is connected with a gas storage device (15) through a gas-liquid separation device (16), and the bottom of the gas-liquid separation device (16) is connected with the water circulation heat exchange loop.

5. An isothermal compressed air energy storage device according to claim 1, wherein, The driving mechanism comprises a crank connecting rod (1) and a driving piece (2), one end of the crank connecting rod (1) is provided with a plunger (3), and the other end of the crank connecting rod (1) is connected with the driving piece (2).

6. An isothermal compressed air energy storage device according to claim 1, wherein, A compression cylinder cover (4) is arranged at the top of the compression cylinder body (10), a through hole is formed in the compression cylinder cover (4), a limiting ring is arranged on the compression cylinder cover (4) and extends downward along the inner diameter of the through hole, and the plunger (3) is slidably connected to the limiting ring.

Images