Normal-temperature heat accumulating type waste mine filling and pipeline burying compressed air energy storage system and using method

Abstract

The invention discloses a normal-temperature heat accumulating type waste mine filling and pipeline burying compressed air energy storage system and a using method. Comprising a compressed air storage pipeline, a heat storage chamber, a first heat exchange pipeline, a first expansion machine or turbine, a second heat exchange pipeline and a generator. And the compressed air storage pipeline and the heat storage chamber are connected through a first heat exchange pipeline for circulating heat exchange. The heat storage cavity and the compressed air storage pipeline are connected through a second heat exchange pipeline to conduct circulating heat exchange, and the two ends of the second heat exchange pipeline are connected with an inlet and an outlet of the first expansion machine or the turbine motor respectively. The heat exchange medium in the second heat exchange pipeline is a mixture of propane and butane and is in a gaseous state at normal temperature. And the generator is connected with the first expansion machine or the turbine. According to the energy storage system, normal-temperature heat storage can be achieved, so that heat loss caused by the fact that the temperature of the heat storage cavity is higher than the environment temperature due to stored heat is reduced, and the heat utilization rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of mine energy storage, and in particular to a normal temperature heat storage abandoned mine filling buried pipeline compressed air energy storage system and a use method thereof. Background Art

[0002] Although solar energy, wind energy and other energy sources that do not rely on fossil fuels for power generation have the advantage of being cleaner and greener, they are affected by weather changes, resulting in unstable power generation and poor controllability. Therefore, it is not appropriate to directly integrate the electricity they generate into the power grid. Compressed gas energy storage technology provides a good solution to the above problems. This technology uses excess electricity to compress gas into the gas storage pipeline, releases it again during peak power consumption, and uses the compressed potential energy of the air to generate electricity, thereby improving the regulation capacity of the power grid. At the same time, compressed air energy storage has technical advantages such as large scale, long-term energy storage, and high safety. Compared with traditional power generation technology, compressed air storage technology does not produce carbon emissions and solid waste, so it is also a green renewable energy utilization technology.

[0003] In the process of compressing gas with a compressor, the temperature of the gas will rise to above 100°C. This heat will eventually dissipate from the gas storage pipeline to the outside world, causing a lot of energy waste. This is an important factor leading to the low capacity utilization of compressed gas energy storage technology. In order to solve the above problems, heat exchange technology is currently usually used to transfer this heat to the heat storage chamber for storage. Then, when the compressed air is released to generate electricity, this heat is used to reheat the compressed air to increase its power generation. However, this method also has the problem of gradual heat dissipation in the heat storage chamber, resulting in losses and low heat exchange rate. Moreover, the longer the storage time, the greater the loss and the lower the heat utilization rate. Summary of the invention

[0004] In view of the above problems, the present invention provides a normal temperature heat storage abandoned mine filling buried pipeline compressed air energy storage system and a method of use, which can realize normal temperature heat storage, thereby reducing the heat loss caused by the heat storage chamber being higher than the ambient temperature due to the stored heat, and improving the utilization rate of heat. Specifically, the technical solution of the present invention is as follows.

[0005] First, the present invention discloses a normal temperature heat storage abandoned mine filling buried pipeline compressed air energy storage system and a method of use, comprising: a compressed air storage pipeline, a heat storage chamber, a first heat exchange pipeline, a first expander or turbine, a second heat exchange pipeline, a pump body and a generator. Wherein: the compressed air storage pipeline and the heat storage chamber are connected by a first heat exchange pipeline for cyclic heat exchange. The heat storage chamber and the compressed air storage pipeline are connected by a second heat exchange pipeline for cyclic heat exchange, and the two ends of the second heat exchange pipeline are respectively connected to the inlet and outlet of the first expander or turbine. The heat exchange medium stored in the second heat exchange pipeline is a mixture of propane and butane, which has a low boiling point and is gaseous at room temperature, and changes to liquid below the boiling point. The pump body is provided on both the first heat exchange pipeline and the second heat exchange pipeline to drive the flow of the heat exchange medium. The generator is connected to the first expander or turbine to drive the generator to generate electricity.

[0006] Furthermore, the compressed air storage pipeline can be laid in the tunnel of an abandoned mine to make resource utilization of the abandoned mine.

[0007] Furthermore, the outside of the compressed air storage pipeline is filled with granules, so as to play a certain role in heat preservation and reducing heat loss. Optionally, the granules include at least one of slag, steel slag, recycled concrete aggregate, etc.

[0008] Furthermore, the boiling point range of the propane and butane is controlled between -10 and -1°C.

[0009] Furthermore, the first heat exchange pipe is located on the compressed air storage pipe, the outer wall of the pipe outside the heat storage chamber, and the outer wall of the heat storage chamber, and is covered with an insulation layer to reduce heat loss. Optionally, the material of the insulation layer includes any one of rock wool, polyurethane foam material, etc.

[0010] Furthermore, the exhaust port of the compressed air storage pipeline, the second expander or turbine, and the generator are connected in sequence.

[0011] Furthermore, the air inlet of the compressed air storage pipeline is connected to the gas compressor.

[0012] Furthermore, the gas compressor is connected to an electric motor to drive the gas compressor to compress the gas.

[0013] Optionally, the first heat exchange pipeline and the compressed air storage pipeline are connected in a manner that the first heat exchange pipeline is wound around the compressed air storage pipeline to facilitate heat exchange between the two.

[0014] Optionally, the first heat exchange pipe and the heat storage chamber are connected in a form in which the first heat exchange pipe passes through the liquid heat exchange medium in the heat storage chamber to facilitate heat exchange between the two.

[0015] Optionally, the heat storage medium in the heat storage chamber and the liquid heat exchange medium in the first heat exchange pipe include any one of water, heat transfer oil and the like.

[0016] Secondly, the present invention discloses a method for using the thermal storage abandoned mine filling buried pipeline compressed air energy storage system, comprising the following steps: (1) When the compressed air is charged into the compressed air storage pipeline, the circulation of the liquid heat exchange medium in the first heat exchange pipeline is started to transfer the heat in the compressed air to the heat storage medium in the heat storage chamber. During this process, the flow of the heat exchange medium in the second heat exchange pipeline is not started.

[0017] (2) During the stage of power generation by releasing compressed air from the compressed air storage pipeline, the flow of the liquid heat exchange medium in the first heat exchange pipeline and the heat exchange medium in the second heat exchange pipeline is started at the same time. In this process, the compressed air storage pipeline heats the compressed air by heat exchange with the heat storage chamber, thereby increasing the power generation. The gaseous heat exchange medium in the second heat exchange pipeline passes through the first expander or turbine to perform work, and the first expander or turbine drives the generator to generate electricity. Then, heat exchange is performed through the compressed air storage pipeline to heat the compressed air therein. Then, the heat exchange medium in the second heat exchange pipeline is converted into liquid, continues to flow through the heat storage chamber, is heated and becomes gaseous again, and then enters the first expander or turbine again to repeat the above process, thereby realizing efficient utilization of the heat in the heat storage chamber.

[0018] Compared with the prior art, the present invention has at least the following beneficial technical effects: The compressed air energy storage system of the present invention realizes heat storage at room temperature, thereby reducing the heat loss caused by the heat storage chamber being higher than the ambient temperature due to the stored heat, and improving the utilization rate of heat. This is because: when the heat energy generated in the stage of filling the compressed air into the compressed air storage pipeline is transferred to the heat storage chamber for storage, the problem of heat loss will inevitably occur, especially as the storage time increases, the retained heat will become less and less. In this case, in the stage of releasing compressed air to generate electricity from the compressed air storage pipeline, the traditional method of using the residual heat in the heat storage chamber and using the water in the heat exchange pipeline as the heat exchange medium to directly heat the compressed air storage pipeline obviously has the problems of low heat exchange efficiency and low heat utilization, resulting in the inability to heat the gas in the compressed air storage pipeline in time, and the inability to fully utilize the heat in the heat storage chamber. To this end, the present invention provides a second heat exchange pipeline with a mixture of propane and butane as the heat exchange medium and a first expander or turbine, and the heat storage chamber and the compressed air storage pipeline are connected through the second heat exchange pipeline for cyclic heat exchange, and the two ends of the second heat exchange pipeline are respectively connected to the inlet and outlet of the first expander or turbine.

[0019] Through the above-mentioned route of heat exchange between the compressed air storage pipeline and the heat storage chamber by means of the first heat exchange pipeline, and the other route of heat exchange between the compressed air storage pipeline and the heat storage chamber by means of the first expander or turbine and the second heat exchange pipeline, not only can the energy in the heat storage chamber be fully utilized, even if the temperature in the heat storage chamber has dropped to room temperature, it can still be utilized. In addition, the reverse absorption and utilization of the energy in the environment is realized, which is equivalent to indirectly reducing the heat loss caused by the heat storage chamber dissipating heat to the environment during the heat storage process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] Figure 1 The following is a schematic diagram of the structure of the heat storage abandoned mine filling and burying pipeline compressed air energy storage system in the following embodiment. The reference numerals represent: 1-compressed air storage pipeline, 2-heat storage chamber, 3-first heat exchange pipeline, 4-first expander or turbine, 5-second heat exchange pipeline, 6-pump body, 7-generator, 8-second expander or turbine, 9-gas compressor, 10-motor. DETAILED DESCRIPTION

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0023] For the convenience of description, if the words "up", "down", "left" and "right" appear in the present invention, they only indicate that they are consistent with the up, down, left and right directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or component needs to have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0024] The normal temperature heat storage abandoned mine filling buried pipeline compressed air energy storage system and the use method of the present invention are further described in conjunction with the drawings and specific embodiments of the specification.

[0025] refer to Figure 1 , an example of a heat storage abandoned mine filling buried pipeline compressed air energy storage system, including: a compressed air storage pipeline 1, a heat storage chamber 2, and a first heat exchange pipeline 3. Specifically: the compressed air storage pipeline 1 is arranged in the tunnel of the abandoned mine to make resource utilization of the abandoned mine. The heat storage chamber 2 is arranged on one side of the compressed air storage pipeline 1, and the first heat exchange pipeline 3 is wound on the outer wall of the compressed air storage pipeline 1 so that heat exchange can be carried out between the two, and any other suitable heat exchange form can also be adopted. At the same time, the first heat exchange pipeline 3 passes through the liquid heat exchange medium in the heat storage chamber 2, thereby forming a first circulation heat exchange system between the compressed air storage pipeline 1 and the heat storage chamber 2. When in use, the liquid heat exchange medium in the heat storage chamber 2 and the first heat exchange pipeline 3 can be selected from water, heat transfer oil, etc. At the same time, in order to drive the circulation of the liquid heat exchange medium in the first heat exchange pipeline 3, the first heat exchange pipeline 3 is provided with the pump body 6.

[0026] Furthermore, the energy storage system also includes a first expander or turbine 4, a second heat exchange pipe 5, a pump body 6 and a generator 7. Specifically, the second heat exchange pipe 5 is wound around the outer wall of the compressed air storage pipe 1 so as to exchange heat between the two, and any other suitable heat exchange form can also be adopted. At the same time, the second heat exchange pipe 5 passes through the liquid heat exchange medium in the heat storage chamber 2, and the two ends of the second heat exchange pipe 5 are respectively connected to the inlet and outlet of the first expander or turbine 4, thereby forming a second circulation heat exchange system between the compressed air storage pipe 1 and the heat storage chamber 2.

[0027] In this embodiment, the heat exchange medium stored in the second heat exchange pipe 5 is a mixture of propane and butane. For example, when the boiling point of the propane and butane is between -10 and -1°C (such as -10°C, -5°C, -1°C, etc.), the heat exchange medium is gaseous at room temperature and turns into liquid when it is lower than the boiling point, so that the heat exchange medium can also perform heat exchange at above 0°C. The pump body 6 is also provided on the second heat exchange pipe 5 to drive the flow of the heat exchange medium in the second heat exchange pipe 5. The first expander or turbine 4 is connected to the generator 7 to drive the generator 7 to generate electricity.

[0028] In another embodiment, continue to refer to Figure 1 The thermal storage type abandoned mine filling and burying pipeline compressed air energy storage system of the above embodiment further includes a second expander or turbine 8. The inlet of the second expander or turbine 8 is connected to the exhaust port of the compressed air storage pipeline 1, and the outlet of the second expander or turbine 8 is connected to the generator 7, so that the compressed gas released by the compressed air storage pipeline 1 drives the second expander or turbine 8 to rotate, thereby driving the generator 7 to generate electricity.

[0029] In another embodiment, the thermal storage abandoned mine filling buried pipeline compressed air energy storage system of the above embodiment further includes a thermal insulation layer. The first heat exchange pipeline 3 is located on the compressed air storage pipeline 1, the outer wall of the part of the pipeline outside the heat storage chamber 2, and the outer wall of the heat storage chamber 2 are all covered with a thermal insulation layer to reduce heat loss. Optionally, the material of the thermal insulation layer can be selected from rock wool, polyurethane foam material, etc.

[0030] In another embodiment, the outside of the compressed air storage pipeline 1 of the heat storage type abandoned mine filling buried pipeline compressed air energy storage system in the above-mentioned embodiment is filled with particulate matter, and the particulate matter can be selected from one or more of slag, steel slag, recycled concrete aggregate, etc., so as to play a certain thermal insulation role, help reduce the heat loss of compressed air in the compressed air storage pipeline 1, and increase power generation.

[0031] In another embodiment, continue to refer to Figure 1 The thermal storage abandoned mine filling and burying pipeline compressed air energy storage system of the above embodiment also includes a gas compressor 9 and a motor 10. The motor 10 is connected to the gas compressor 9, and the gas compressor 9 is connected to the air inlet of the compressed air storage pipeline 1 so as to fill the compressed air into the compressed air storage pipeline 1.

[0032] When in use, (1) when the compressed air is charged into the compressed air storage pipeline 1, the temperature of the gas rises rapidly after being compressed (PV=nRT, P-pressure, V-volume, n-amount of substance, R-constant, T-temperature). Therefore, after the pump body 6 on the first heat exchange pipeline 3 is started, the liquid heat exchange medium in the first heat exchange pipeline 3 is driven to circulate, and the liquid heat exchange medium is heated by the high-temperature gas in the compressed air storage pipeline 1 to become a high-temperature heat exchange medium, and then enters the heat storage chamber 2 to heat the heat storage medium therein, thereby transferring the heat in the compressed air to the heat storage medium in the heat storage chamber 2. During this process, the flow of the heat exchange medium in the second heat exchange pipeline 5 is not started.

[0033] (2) When the temperature difference between the gas temperature in the compressed air storage pipeline 1 and the heat storage medium in the heat storage chamber 2 approaches zero, the operation of the pump body 6 on the first heat exchange pipeline 3 is stopped, thereby stopping the heat exchange between the compressed air storage pipeline 1 and the heat storage chamber 2. At this time, the heat storage medium in the heat storage chamber 2 is in a high temperature state. However, as the storage time increases, the problem of heat loss will inevitably occur, resulting in less and less heat retained by the heat storage medium in the heat storage chamber 2. In this case, when the compressed air storage pipeline 1 releases compressed air to the outside to generate electricity, the traditional method of using the residual heat in the heat storage chamber 2 and using the heat exchange medium in the first heat exchange pipeline 3 to directly heat the compressed air storage pipeline 1 obviously has the problem of low heat exchange efficiency and low heat utilization rate, resulting in the inability to heat the gas in the compressed air storage pipeline 1 in time and the inability to fully utilize the heat in the heat storage chamber 2.

[0034] In the second circulating heat exchange system of the above-mentioned embodiment, a mixture of propane and butane is used as the heat exchange medium of the second heat exchange pipe 5 (referred to as propane-butane medium). During the stage of the compressed air storage pipe 1 releasing compressed air to generate electricity, since the liquid propane-butane medium can absorb heat from the environment, the medium maintains a gaseous expansion state. When the pump body 6 on the second heat exchange pipe 5 is started, the gaseous propane-butane medium therein is driven to flow through the first expander or turbine 4 first. At this time, the volume expansion of the propane-butane medium can be used to work the first expander or turbine 4, and then drive the generator 7 to generate electricity, thereby realizing the utilization of the internal energy of the propane-butane medium and also realizing the reverse recovery of heat in the environment. Then, when the gaseous propane-butane medium continues to pass through the compressed air storage pipeline 1, the temperature of the compressed air storage pipeline 1 drops to below zero due to the release of gas (same as above, PV=nRT), resulting in a large temperature difference between the propane-butane medium and the compressed air storage pipeline 1, thereby achieving a more rapid and efficient heat exchange between the two, quickly increasing the temperature of the gas in the compressed air storage pipeline 1, and improving the power generation efficiency. At this time, the propane-butane medium releases a large amount of heat and its temperature drops below the boiling point to become liquid. Then the liquid propane-butane medium will exchange heat with the heat storage chamber 2. At this time, even if the temperature in the heat storage chamber 2 has dropped to room temperature due to heat exchange or long-term heat storage, the liquid propane-butane medium can quickly absorb heat from the heat storage chamber 2 and become gaseous again. Then it re-enters the first expander or turbine 4 to perform work. In addition, since the propane-butane medium changes from liquid to gas and continuously absorbs heat from the heat storage chamber 2, the heat storage medium in the heat storage chamber 2 will be in a state below normal temperature, which will also prompt the heat storage medium in the heat storage chamber 2 to reversely absorb and utilize energy in the environment, and in the compressed air filling stage of the next cycle, fully exchange heat with the high-temperature gas in the compressed air storage pipeline 1, thereby improving the heat exchange efficiency.

[0035] Through the cooperation between the first circulating heat exchange system in which the compressed air storage pipeline 1 and the heat storage chamber 2 exchange heat with the help of the first heat exchange pipeline 3, and the second circulating heat exchange system in which the compressed air storage pipeline 1 and the heat storage chamber 2 exchange heat with the help of the first expander or turbine 4 and the second heat exchange pipeline 5, not only can the energy in the heat storage chamber 2 be fully utilized, but it can also be utilized even if the temperature in the heat storage chamber 2 has dropped to room temperature. It also realizes the reverse absorption and utilization of energy in the environment, which is equivalent to indirectly reducing the heat loss caused by the heat storage chamber 2 dissipating heat to the environment during the heat storage process. In summary, the compressed air energy storage system of the present invention realizes the purpose of fully utilizing heat while storing heat at room temperature, thereby overcoming the problem that the heat in the heat storage chamber cannot be fully utilized due to the heat loss caused by the heat storage chamber being higher than the ambient temperature due to the stored heat.

[0036] Finally, it should be noted that any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. Although the above describes the specific implementation of the present invention in conjunction with the drawings, it is not a limitation of the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative labor are still within the protection scope of the present invention.

Claims

1. A normal temperature thermal storage abandoned mine filling buried pipeline compressed air energy storage system and use method, characterized in that: include: Compressed air storage pipeline; A heat storage chamber, wherein the compressed air storage pipeline and the heat storage chamber are connected via a first heat exchange pipeline for cyclic heat exchange; The first expander or turbine, the heat storage chamber and the compressed air storage pipeline are connected through a second heat exchange pipeline for cyclic heat exchange, and the two ends of the second heat exchange pipeline are respectively connected to the inlet and outlet of the first expander or turbine; the heat exchange medium stored in the second heat exchange pipeline is a mixture of propane and butane, which is gaseous at room temperature and changes into liquid when it is below the boiling point; A pump body, wherein the first heat exchange pipe and the second heat exchange pipe are both provided with the pump body; A generator is connected to the first expansion machine or the turbine.

2. The thermal storage abandoned mine filling buried pipeline compressed air energy storage system and use method according to claim 1 is characterized in that: The compressed air storage pipeline is arranged in the tunnel of the abandoned mine; Optionally, the outside of the compressed air storage pipeline is filled with heat-insulating particles; Optionally, the particulate matter includes at least one of slag, steel slag, and recycled concrete aggregate; Optionally, the boiling point range of the propane and butane is controlled between -10 and -1°C.

3. The thermal storage abandoned mine filling buried pipeline compressed air energy storage system and use method according to claim 1 is characterized in that: The outer wall of the first heat exchange pipeline located outside the compressed air storage pipeline and the heat storage chamber is coated with a thermal insulation layer; Preferably, the outer wall of the heat storage chamber is coated with a heat-insulating layer; Optionally, the material of the thermal insulation layer includes any one of rock wool and polyurethane foam material.

4. The thermal storage abandoned mine filling buried pipeline compressed air energy storage system and use method according to claim 1 is characterized in that: The exhaust port of the compressed air storage pipeline, the second expander or turbine, and the generator are connected in sequence.

5. The thermal storage abandoned mine filling buried pipeline compressed air energy storage system and use method according to claim 1 is characterized in that: The air inlet of the compressed air storage pipeline is connected to the gas compressor.

6. The thermal storage abandoned mine filling buried pipeline compressed air energy storage system and use method according to claim 5 is characterized in that: The gas compressor is connected to the electric motor.

7. The thermal storage abandoned mine filling buried pipeline compressed air energy storage system and use method according to any one of claims 1 to 6, characterized in that: The first heat exchange pipeline and the compressed air storage pipeline are connected in a form in which the first heat exchange pipeline is wound around the compressed air storage pipeline.

8. The thermal storage abandoned mine filling buried pipeline compressed air energy storage system and use method according to any one of claims 1 to 6, characterized in that: The first heat exchange pipe and the heat storage chamber are connected in a form in which the first heat exchange pipe passes through the liquid heat exchange medium in the heat storage chamber.

9. The thermal storage abandoned mine filling buried pipeline compressed air energy storage system and use method according to claim 8, characterized in that: The heat storage medium in the heat storage chamber and the liquid heat exchange medium in the first heat exchange pipe include any one of water and heat transfer oil.

10. The method for using the thermal storage abandoned mine filling and buried pipeline compressed air energy storage system according to any one of claims 1 to 9, characterized in that: The steps include: (1) When the compressed air is charged into the compressed air storage pipeline, the circulation of the liquid heat exchange medium in the first heat exchange pipeline is started to transfer the heat in the compressed air to the heat storage medium in the heat storage chamber; during this process, the flow of the heat exchange medium in the second heat exchange pipeline is not started; (2) During the stage of releasing compressed air from the compressed air storage pipeline to generate electricity, the flow of the liquid heat exchange medium in the first heat exchange pipeline and the heat exchange medium in the second heat exchange pipeline are started at the same time; during this process, the compressed air storage pipeline heats the compressed air by heat exchange with the heat storage chamber; the gaseous heat exchange medium in the second heat exchange pipeline passes through the first expander or turbine to perform work, and the first expander or turbine drives the generator to generate electricity; then the compressed air therein is heated by heat exchange through the compressed air storage pipeline; then the heat exchange medium in the second heat exchange pipeline is converted into liquid, continues to flow through the heat storage chamber, is heated and becomes gaseous again, and then enters the first expander or turbine again to repeat the above process.

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