CN-224228735-U - Compressed air energy storage system

Abstract

The utility model relates to a compressed air energy storage system in the technical field of compressed air energy storage, which comprises a compression unit, an energy storage unit, an expansion unit and an energy supplementing unit, wherein the compression unit is a cascade type compression mechanism, the expansion unit is a cascade type expansion mechanism, the number of compressors is the same as that of the expansion machines, the energy storage unit receives compressed air output by a final stage compressor and outputs the compressed air into a primary expansion machine, the energy supplementing unit comprises an energy supplementing assembly formed by connecting an air storage tank and a third heat exchanger in series, each stage of compressors before the final stage and each stage of expansion machines after the primary stage are communicated through a group of energy supplementing assemblies, part of compressed air output by the compressors is input into the air storage tank through a branch pipeline, the compressed air in the air storage tank is mixed with the compressed air output by the self-expansion machines after heat exchange of the third heat exchangers, and the temperature of the compressed air output by the third heat exchangers is higher than the temperature of the compressed air output by the self-expansion machines. The utility model can effectively improve the system electric conversion efficiency.

Inventors

• LIN HONGLIANG
• YUAN KE
• SUN DANDAN
• QIAN ZENG
• ZHANG YE
• HE NAN
• LI GUANGYAO
• CAI YONGXIANG
• XIA CHAO
• CHEN JUN

Assignees

• 南通万达能源动力科技有限公司

Dates

Publication Date

20260512

Application Date

20250522

Claims (6)

1. 1. The compressed air energy storage system is characterized by comprising a compression unit, an energy storage unit, an expansion unit and an energy supplementing unit; The compression unit comprises a cascade type compression mechanism formed by connecting a plurality of compressors (110) in series, the expansion unit comprises a cascade type expansion mechanism formed by connecting a plurality of expanders (310) in series, the number of the compressors (110) is the same as that of the expanders (310), and the energy storage unit receives compressed air output by the final-stage compressor (110) and outputs the compressed air into the primary expander (310); The energy supplementing unit comprises an energy supplementing component (410) formed by connecting an air storage tank (411) and a third heat exchanger (412) in series, wherein each stage of the energy supplementing component (410) is communicated with each stage of the expander (310) which is positioned behind a final stage, part of compressed air output from the compressor (110) is input into the air storage tank (411) through a branch pipeline, and the compressed air in the air storage tank (411) is mixed with the compressed air output from the expander (310) after heat exchange of the third heat exchanger (412), and the temperature of the compressed air output from the third heat exchanger (412) is higher than the temperature of the compressed air output from the expander (310).
2. 2. The compressed air energy storage system according to claim 1, wherein the energy supplementing assembly (410) is further provided with an electric regulating valve (413) and a flow meter (414), and the electric regulating valve (413) and the flow meter (414) are sequentially connected in series on a pipeline between the compressor (310) and the air storage tank (411).
3. 3. The compressed air energy storage system of claim 2, wherein the energy charging unit further comprises a hot molten salt storage tank (420) and a cold molten salt storage tank (430), wherein a heat exchange medium inlet of the third heat exchanger (412) is in communication with the hot molten salt storage tank (420) outlet, and wherein a heat exchange medium outlet of the third heat exchanger (412) is in communication with the cold molten salt storage tank (430) inlet.
4. 4. A compressed air energy storage system according to claim 3, wherein the compression unit further comprises a first heat exchanger (120), the first heat exchanger (120) is arranged between two adjacent stages of compressors (110) and between the last stage of compressors (110) and the energy storage unit, and compressed air output by the compressors (110) is respectively delivered to the first heat exchanger (120) and the air storage tank (411) through a main pipeline and a branch pipeline.
5. 5. The compressed air energy storage system according to claim 4, wherein the energy storage unit comprises a high pressure air tank (210), a cold desalination water tank (220) and a hot desalination water tank (230), the compressor (110) of the final stage is in communication with the high pressure air tank (210) through the first heat exchanger (120), a heat exchange medium inlet of the first heat exchanger (120) is in communication with an outlet of the cold desalination water tank (220), and a heat exchange medium outlet of the first heat exchanger (120) is in communication with an inlet of the hot desalination water tank (230).
6. 6. The compressed air energy storage system according to claim 5, wherein the expansion unit further comprises a second heat exchanger (320), the second heat exchanger (320) being arranged between the primary expander (310) and the high pressure air tank (210) and between two adjacent stages of the expanders (310), the heat exchange medium inlet of the second heat exchanger (320) being in communication with the outlet of the hot brine tank (230), the heat exchange medium outlet of the second heat exchanger (320) being in communication with the inlet of the cold brine tank (220).

Description

Compressed air energy storage system Technical Field The utility model relates to the technical field of compressed air energy storage, in particular to a compressed air energy storage system. Background The compressed air energy storage is taken as a novel energy storage technology, has the outstanding advantages of large energy storage scale, long service life, relatively low cost and the like, and is being widely focused and applied to demonstration. The compressed air energy storage system mainly comprises a compressor unit, an expansion unit, a gas storage system, a heat storage and exchange system and the like, wherein the heat storage and exchange system is a key device for realizing energy recovery and reutilization and is also a key device for influencing the electric conversion efficiency of the system. In the compressed air energy storage system, because the expander is generally in the power consumption peak period when doing work, the energy can not be supplemented to the system, so that the parameter change of the compressed air is larger, the optimal efficiency point of the expander is confirmed when the system is designed, the optimal efficiency point of the expander can not be changed along with the parameter change of the compressed air, and when the parameter of the compressed air such as pressure and temperature deviate from a design value greatly, the efficiency of the expander can be rapidly reduced, so that the running efficiency of the whole system is reduced. And part of compressed air is led out from the high-pressure air tank for energy storage to supplement the energy of the expander after the primary expander, so that the efficiency of the expander can be improved to a certain extent, but the compressed air in the high-pressure air tank for energy storage is high-pressure air formed after being compressed by the multi-stage compressor, so that the pressure matching degree of the high-pressure air and the compressed air discharged after acting from the upper-stage expander is poor when the low-level expander is compensated, and the mixing effect is difficult to ensure. For example, patent publication No. CN108316982a discloses a compressed air energy storage expander system, the system includes a compressed air storage tank and a heat exchanger, the outlet of the compressed air storage tank is connected with a quick-closing valve, the quick-closing valve is connected with a regulating valve and a gas compensating valve respectively, the regulating valve and the gas compensating valve are connected with a cold side inlet of the heat exchanger respectively, a cold side outlet of the heat exchanger is connected with an expander inlet, a transmission shaft between the expanders is connected, a rightmost expander is connected with a generator transmission shaft, a hot side inlet of the heat exchanger is connected with a heat storage tank, a hot side outlet of the heat exchanger is connected with the heat storage tank, the number of the expanders is greater than or equal to two, parameters of compressed air before each expander are changed by utilizing the regulating characteristics of the gas compensating valve, and the output power of the expander of the system is not less than the power required by the system. This patent presents the above-mentioned related problems. Disclosure of utility model In view of the drawbacks of the prior art, an object of the present utility model is to provide a compressed air energy storage system. The compressed air energy storage system comprises a compression unit, an energy storage unit, an expansion unit and an energy supplementing unit; The compression unit comprises a cascade type compression mechanism formed by connecting a plurality of compressors in series, the expansion unit comprises a cascade type expansion mechanism formed by connecting a plurality of expanders in series, the number of the compressors is the same as that of the expanders, and the energy storage unit receives compressed air output by the compressor of the final stage and outputs the compressed air into the expander of the primary stage; The energy supplementing unit comprises an energy supplementing assembly formed by connecting an air storage tank and a third heat exchanger in series, wherein each stage of the energy supplementing assembly is positioned in front of the final stage, the compressor and each stage of the expander positioned behind the final stage are communicated and arranged through a group of energy supplementing assemblies, part of compressed gas output from the compressor is input into the air storage tank through a branch pipeline, compressed air in the air storage tank is mixed with compressed air output from the expander after heat exchange of the third heat exchanger, and the temperature of the compressed air output from the third heat exchanger is higher than that of the compressed air output from the expander. In some embodiments, the energy supple