Compressed air energy storage system

Abstract

The invention discloses a compressed air energy storage system which comprises an energy storage unit, an energy release unit, a liquid heat regeneration unit and an air storage tank, the air storage tank is provided with a water inlet, an air inlet, a water outlet and an air outlet, and the energy storage unit is connected with the air inlet through a pipeline. The water outlet and the water inlet are respectively connected with the liquid heat regeneration unit through pipelines, and the energy release unit is connected with the air outlet through a pipeline; the liquid heat regeneration unit comprises a cold storage water tank connected with the water outlet, a hot storage water tank connected with the water inlet and a first heat exchanger set used for heating the cold storage water tank, the two ends of the first heat exchanger set are connected with the cold storage water tank and the hot storage water tank correspondingly, and cold water flowing out of the cold storage water tank is heated to the temperature of the first heat exchanger set. After passing through the first heat exchanger set, the temperature is increased, then the air enters the heat storage water tank, the first heat exchanger set is a multi-stage first heat exchanger, and a bypass pipeline is arranged between every two stages of heat exchangers and used for adjusting water flow and controlling the temperature, so that the density of air in the tank can be reduced, and the air displacement of the air storage tank is increased; therefore, the effective gas storage density of the gas storage tank is improved, and the investment cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of air energy storage, and in particular relates to a compressed air energy storage system. Background Art

[0002] As energy and environmental issues become increasingly prominent, renewable energy such as wind power and solar energy are receiving more and more attention. However, the volatility and randomness of renewable energy and the insufficient peak-shaving capacity of the existing power grid have brought huge challenges to the development of renewable energy. As a transition system between power plants and power grids, energy storage systems can effectively solve the problem of grid connection of renewable energy. In addition, energy storage systems can also smooth out load fluctuations in the power grid and improve the safety and controllability of the power grid. Summary of the invention

[0003] To achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a compressed air energy storage system, comprising an energy storage unit, an energy release unit, a liquid heat recovery unit and an air storage tank, wherein the air storage tank is provided with a water inlet, an air inlet, a water outlet and an air outlet, the energy storage unit is connected to the air inlet through a pipeline, the water outlet and the water inlet are respectively connected to the liquid heat recovery unit through pipelines, and the energy release unit is connected to the air outlet through a pipeline; the liquid heat recovery unit comprises a cold water storage tank connected to the water outlet, a hot water storage tank connected to the water inlet and a first heat exchanger group for heating the cold water storage tank, the two ends of the first heat exchanger group are respectively connected to the cold water storage tank and the hot water storage tank, the cold water flowing out of the cold water storage tank is increased in temperature after passing through the first heat exchanger group, and then enters the hot water storage tank, the first heat exchanger group is a multi-stage first heat exchanger, and a bypass pipe is provided between each stage of the heat exchanger for adjusting the water flow and controlling the temperature.

[0004] Preferably, it also includes a heat storage unit, which includes a hot oil tank that absorbs and stores the heat of the energy storage unit through a high-temperature medium and provides heat to the energy release unit, and a cold oil tank that recovers and stores excess waste heat of the energy release unit and the liquid heat recovery unit through a high-temperature medium. The high-temperature medium is heat transfer oil, and a heat exchanger is provided between the hot oil tank and the cold oil tank for exchanging heat during the circulation of the high-temperature medium.

[0005] Preferably, the heat storage unit also includes a first oil pump and a second oil pump, the first oil pump drives the high-temperature medium into the energy storage unit to absorb heat and then stores it in the hot oil tank, and drives the high-temperature medium to flow out of the hot oil tank and provide heat to the energy release unit; the second oil pump drives the high-temperature medium into the energy release unit and the liquid heat recovery unit to absorb excess heat and then stores it in the cold oil tank, and drives the high-temperature medium to mix the waste heat flowing out of the cold oil tank with the compression heat of the energy storage unit, and the high-temperature medium is driven by the first oil pump to enter the hot oil tank.

[0006] Preferably, the gas storage tank has an insulation layer, which includes a vacuum multi-layer insulation pipe winding layer structure, and multiple vacuum areas are created in the insulation layer, wherein the vacuum area includes a main heat-maintaining area, a transition area and an edge area, wherein the areas of the main heat-maintaining area, the transition area and the edge area decrease successively, and the gas storage tank also includes an epoxy migration barrier layer arranged between the EPDM insulation layer and the HTPB lining layer.

[0007] Preferably, the energy storage unit comprises at least two compressors connected in series, each compressor being equipped with a temperature sensor and a pressure sensor for real-time monitoring of the temperature and pressure of the compressed air.

[0008] Preferably, the energy release unit comprises at least one expander, and the air inlet of the expander is connected to the air outlet of the air storage tank.

[0009] Preferably, the liquid heat recovery unit also includes a second heat exchanger group, one end of which is connected to the hot water tank, and the other end is connected to the air inlet of the gas tank, for transferring the heat of the hot water in the hot water tank to the compressed air entering the gas tank.

[0010] Preferably, the system further comprises a control system, which controls the working states of the compressor, the expander, the oil pump and the heat exchanger by collecting data from various sensors to achieve optimal operation of the system.

[0011] Preferably, the system further comprises a safety valve, which is installed on the top of the gas storage tank and is used for automatically releasing the pressure when the pressure in the gas storage tank exceeds a set value.

[0012] Preferably, the system further comprises an energy management system, which can automatically adjust the energy storage and release process according to the grid load and the energy storage state of the energy storage unit to achieve optimal energy scheduling.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides an adiabatic compressed air energy storage system based on gas tank temperature control, which solves the technical problem of low effective gas storage density of the gas tank of the existing adiabatic compressed air energy storage system. By controlling the temperature of the gas tank, heating hot water with the waste heat in the energy release process, and then spraying hot water into the gas tank to heat the air, the air temperature in the gas tank can be increased, the density of the air in the tank can be reduced, and the exhaust volume of the gas tank can be increased, thereby improving the effective gas storage density of the gas tank and reducing investment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the connection of the compressed air energy storage system described in this embodiment; Figure 2 This is a schematic diagram of the winding layer structure distribution of the vacuum multi-layer insulation pipe described in this embodiment. DETAILED DESCRIPTION

[0015] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0016] Example: Figure 1 As shown, a compressed air energy storage system comprises an energy storage unit, an energy release unit, a liquid heat recovery unit and an air storage tank, wherein the air storage tank is provided with a water inlet, an air inlet, a water outlet and an air outlet, the energy storage unit is connected to the air inlet through a pipeline, the water outlet and the water inlet are respectively connected to the liquid heat recovery unit through pipelines, and the energy release unit is connected to the air outlet through a pipeline; the liquid heat recovery unit comprises a cold water storage tank connected to the water outlet, a hot water storage tank connected to the water inlet and a first heat exchanger group for heating the cold water storage tank, the two ends of the first heat exchanger group are respectively connected to the cold water storage tank and the hot water storage tank, the temperature of the cold water flowing out of the cold water storage tank is increased after passing through the first heat exchanger group, and then enters the hot water storage tank, the first heat exchanger group is a multi-stage first heat exchanger, and a bypass pipe is provided between each stage of the heat exchanger for adjusting the water flow and controlling the temperature.

[0017] Furthermore, it also includes a heat storage unit, which includes a hot oil tank that absorbs and stores the heat of the energy storage unit through a high-temperature medium and provides heat to the energy release unit, and a cold oil tank that recovers and stores excess waste heat of the energy release unit and the liquid heat recovery unit through a high-temperature medium. The high-temperature medium is heat transfer oil, and a heat exchanger is provided between the hot oil tank and the cold oil tank for exchanging heat during the circulation of the high-temperature medium.

[0018] Furthermore, the heat storage unit also includes a first oil pump and a second oil pump, the first oil pump drives the high-temperature medium into the energy storage unit to absorb heat and then stores it in the hot oil tank, and drives the high-temperature medium to flow out of the hot oil tank and provide heat to the energy release unit; the second oil pump drives the high-temperature medium into the energy release unit and the liquid heat recovery unit to absorb excess heat and then stores it in the cold oil tank, and drives the high-temperature medium to mix the residual heat flowing out of the cold oil tank with the compression heat of the energy storage unit, and the high-temperature medium is driven by the first oil pump to enter the hot oil tank.

[0019] Furthermore, if Figure 2 As shown, the gas storage tank has an insulation layer, which includes a vacuum multi-layer insulation pipe winding layer structure, and multiple vacuum areas are created in the insulation layer, wherein the vacuum area includes a main heat-generating area, a transition area, and an edge area, wherein the areas of the main heat-generating area, the transition area, and the edge area decrease in sequence, and the gas storage tank also includes an epoxy migration barrier layer arranged between the EPDM insulation layer and the HTPB lining layer.

[0020] Furthermore, the energy storage unit includes at least two compressors connected in series, and each compressor is equipped with a temperature sensor and a pressure sensor for real-time monitoring of the temperature and pressure of the compressed air.

[0021] Furthermore, the energy release unit includes at least one expander, and the air inlet of the expander is connected to the air outlet of the air storage tank.

[0022] Furthermore, the liquid heat recovery unit also includes a second heat exchanger group, one end of which is connected to the hot water storage tank, and the other end is connected to the air inlet of the gas storage tank, for transferring the heat of the hot water in the hot water storage tank to the compressed air entering the gas storage tank.

[0023] Furthermore, the system also includes a control system, which controls the working states of the compressor, expander, oil pump and heat exchanger by collecting data from various sensors to achieve optimal operation of the system.

[0024] Furthermore, the system also includes a safety valve, which is installed on the top of the gas storage tank and is used to automatically release the pressure when the pressure in the gas storage tank exceeds a set value.

[0025] Furthermore, the system also includes an energy management system, which can automatically adjust the energy storage and release process according to the grid load and the energy storage state of the energy storage unit to achieve optimal energy scheduling.

[0026] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A compressed air energy storage system, characterized in that: It includes an energy storage unit, an energy release unit, a liquid heat recovery unit and an air storage tank. The air storage tank is provided with a water inlet, an air inlet, a water outlet and an air outlet. The energy storage unit is connected to the air inlet through a pipeline, the water outlet and the water inlet are respectively connected to the liquid heat recovery unit through pipelines, and the energy release unit is connected to the air outlet through a pipeline; the liquid heat recovery unit includes a cold water storage tank connected to the water outlet, a hot water storage tank connected to the water inlet and a first heat exchanger group for heating the cold water storage tank, the two ends of the first heat exchanger group are respectively connected to the cold water storage tank and the hot water storage tank, the temperature of the cold water flowing out of the cold water storage tank is increased after passing through the first heat exchanger group, and then enters the hot water storage tank, the first heat exchanger group is a multi-stage first heat exchanger, and a bypass pipe is provided between each stage of the heat exchanger for adjusting the water flow and controlling the temperature.

2. A compressed air energy storage system according to claim 1, characterized in that: It also includes a heat storage unit, which includes a hot oil tank that absorbs and stores the heat of the energy storage unit through a high-temperature medium and provides heat to the energy release unit, and a cold oil tank that recovers and stores excess waste heat of the energy release unit and the liquid heat recovery unit through a high-temperature medium. The high-temperature medium is heat transfer oil, and a heat exchanger is provided between the hot oil tank and the cold oil tank for exchanging heat during the circulation of the high-temperature medium.

3. A compressed air energy storage system according to claim 1, characterized in that: The heat storage unit also includes a first oil pump and a second oil pump. The first oil pump drives the high-temperature medium to enter the energy storage unit to absorb heat and then store it in the hot oil tank, and drives the high-temperature medium to flow out of the hot oil tank and provide heat to the energy release unit; the second oil pump drives the high-temperature medium to enter the energy release unit and the liquid heat recovery unit to absorb excess heat and then store it in the cold oil tank, and drives the high-temperature medium to mix the residual heat flowing out of the cold oil tank with the compression heat of the energy storage unit, and the high-temperature medium is driven by the first oil pump to enter the hot oil tank.

4. A compressed air energy storage system according to claim 1, characterized in that: The gas storage tank has an insulation layer, which includes a vacuum multi-layer insulation pipe winding layer structure. Multiple vacuum areas are created in the insulation layer, wherein the vacuum area includes a main heat-maintaining area, a transition area, and an edge area, wherein the areas of the main heat-maintaining area, the transition area, and the edge area decrease in sequence. The gas storage tank also includes an epoxy migration barrier layer arranged between the EPDM insulation layer and the HTPB lining layer.

5. A compressed air energy storage system according to claim 1, characterized in that: The energy storage unit includes at least two compressors connected in series, each of which is equipped with a temperature sensor and a pressure sensor for real-time monitoring of the temperature and pressure of compressed air.

6. A compressed air energy storage system according to claim 1, characterized in that: The energy release unit comprises at least one expander, and the air inlet of the expander is connected to the air outlet of the air storage tank.

7. A compressed air energy storage system according to claim 1, characterized in that: The liquid heat recovery unit also includes a second heat exchanger group, one end of which is connected to the hot water storage tank, and the other end is connected to the air inlet of the gas storage tank, for transferring the heat of the hot water in the hot water storage tank to the compressed air entering the gas storage tank.

8. A compressed air energy storage system according to claim 1, characterized in that: The system also includes a control system, which controls the working states of the compressor, expander, oil pump and heat exchanger by collecting data from various sensors to achieve optimal operation of the system.

9. A compressed air energy storage system according to claim 1, characterized in that: The system further comprises a safety valve, which is installed on the top of the gas storage tank and is used for automatically releasing the pressure when the pressure in the gas storage tank exceeds a set value.

10. A compressed air energy storage system according to claim 1, characterized in that: The system also includes an energy management system, which can automatically adjust the energy storage and release process according to the grid load and the energy storage state of the energy storage unit to achieve optimal energy scheduling.

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