Air energy storage system and method for deep level cascade utilization of energy

Patent metadata

Field	Value
Publication number	US-12460575-B2
Application number	US-202418440416-A
Country	US
Kind code	B2
Filing date	Feb 13, 2024
Priority date	Feb 15, 2023
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

An air energy storage system for deep level cascade utilization of energy includes a compressor unit, an air storage chamber, a molten salt heat exchanger and a water source heat exchanger. All stages of compressors in the compressor unit are connected in series, a compressed air outlet of the last stage of compressor is connected with an air inlet of the air storage chamber, a pipeline at a compressed air outlet of each stage of compressor in the compressor unit is sequentially provided with the molten salt heat exchanger and the water source heat exchanger along a flow direction of a compressed air, and a hot end of the molten salt heat exchanger and a hot end of the water source heat exchanger are connected to the pipeline at the compressed air outlet of the compressor.

First claim

The invention claimed is:

1 . An air energy storage system for deep level cascade utilization of energy, comprising a compressor unit, a molten salt heat exchanger, a high temperature molten salt tank, an air storage chamber, a middle temperature molten salt tank, a middle temperature molten salt heater, a high temperature molten salt heater, a low temperature molten salt tank, a primary turbine, a secondary turbine, a primary low temperature water source heater, a low temperature water source tank, a water source heat exchanger, a high temperature water source tank, a secondary low temperature water source heater, an expander, a condenser and a circulating pump,
wherein all stages of compressors in the compressor unit are connected in series, a compressed air outlet of the last stage of compressor is connected with an air inlet of the air storage chamber, a pipeline at a compressed air outlet of each stage of compressor in the compressor unit is sequentially provided with the molten salt heat exchanger and the water source heat exchanger along a flow direction of a compressed air, and a hot end of the molten salt heat exchanger and a hot end of the water source heat exchanger are connected to the pipeline at the compressed air outlet of the compressor; a cold inlet of the molten salt heat exchanger is connected with an outlet of the low temperature molten salt tank, a cold outlet of the molten salt heat exchanger is divided into two paths and connected with an inlet of the molten salt heater and an inlet of the middle temperature molten salt tank respectively, and an outlet of the molten salt heater is connected with an inlet of the high temperature molten salt tank; an outlet of the high temperature molten salt tank is connected with a hot inlet of the high temperature molten salt heater, and a hot outlet of the high temperature molten salt heater is connected with a molten salt inlet of the low temperature molten salt tank; an outlet of the middle temperature molten salt tank is connected with a hot inlet of the middle temperature molten salt heater, and a hot outlet of the middle temperature molten salt heater is connected with a molten salt inlet of the low temperature molten salt tank; an air outlet of the air storage chamber is connected with a cold inlet of the primary low temperature water source heater, a cold outlet of the primary low temperature water source heater is connected with a cold inlet of the high temperature molten salt heater, a cold outlet of the high temperature molten salt heater is connected with an air inlet of the primary turbine, an air outlet of the primary turbine is connected with a cold inlet of the middle temperature molten salt heater, a cold outlet of the middle temperature molten salt heater is connected with an air inlet of the secondary turbine, an air outlet of the secondary turbine is connected with a cold inlet of the condenser, a circulating working medium outlet of the expander is connected with a hot inlet of the condenser, a hot outlet of the condenser is connected with an inlet of the circulating pump, an outlet of the circulating pump is connected with a cold inlet of the secondary low temperature water source heater, and a cold outlet of the secondary low temperature water source heater is connected with a circulating working medium inlet of the expander; and a cold inlet of the water source heat exchanger is connected with a water outlet of the low temperature water source tank, and a cold outlet of the water source heat exchanger is connected with a water inlet of the high temperature water source tank.

2 . The air energy storage system for deep level cascade utilization of energy according to claim 1 , wherein a cold outlet of the condenser is communicated with an atmosphere.

3 . A method for deep level cascade utilization of energy, wherein the method is carried out by an air energy storage system for deep level cascade utilization of energy, and comprises an energy storage process and an energy release process,
wherein the air energy storage system for deep level cascade utilization of energy comprises a compressor unit, a molten salt heat exchanger, a high temperature molten salt tank, an air storage chamber, a middle temperature molten salt tank, a middle temperature molten salt heater, a high temperature molten salt heater, a low temperature molten salt tank, a primary turbine, a secondary turbine, a primary low temperature water source heater, a low temperature water source tank, a water source heat exchanger, a high temperature water source tank, a secondary low temperature water source heater, an expander, a condenser and a circulating pump, wherein all stages of compressors in the compressor unit are connected in series, a compressed air outlet of the last stage of compressor is connected with an air inlet of the air storage chamber, a pipeline at a compressed air outlet of each stage of compressor in the compressor unit is sequentially provided with the molten salt heat exchanger and the water source heat exchanger along a flow direction of a compressed air, and a hot end of the molten salt heat exchanger and a hot end of the water source heat exchanger are connected to the pipeline at the compressed air outlet of the compressor; a cold inlet of the molten salt heat exchanger is connected with an outlet of the low temperature molten salt tank, a cold outlet of the molten salt heat exchanger is divided into two paths and connected with an inlet of the molten salt heater and an inlet of the middle temperature molten salt tank respectively, and an outlet of the molten salt heater is connected with an inlet of the high temperature molten salt tank; an outlet of the high temperature molten salt tank is connected with a hot inlet of the high temperature molten salt heater, and a hot outlet of the high temperature molten salt heater is connected with a molten salt inlet of the low temperature molten salt tank; an outlet of the middle temperature molten salt tank is connected with a hot inlet of the middle temperature molten salt heater, and a hot outlet of the middle temperature molten salt heater is connected with a molten salt inlet of the low temperature molten salt tank; an air outlet of the air storage chamber is connected with a cold inlet of the primary low temperature water source heater, a cold outlet of the primary low temperature water source heater is connected with a cold inlet of the high temperature molten salt heater, a cold outlet of the high temperature molten salt heater is connected with an air inlet of the primary turbine, an air outlet of the primary turbine is connected with a cold inlet of the middle temperature molten salt heater, a cold outlet of the middle temperature molten salt heater is connected with an air inlet of the secondary turbine, an air outlet of the secondary turbine is connected with a cold inlet of the condenser, a circulating working medium outlet of the expander is connected with a hot inlet of the condenser, a hot outlet of the condenser is connected with an inlet of the circulating pump, an outlet of the circulating pump is connected with a cold inlet of the secondary low temperature water source heater, and a cold outlet of the secondary low temperature water source heater is connected with a circulating working medium inlet of the expander; and a cold inlet of the water source heat exchanger is connected with a water outlet of the low temperature water source tank, and a cold outlet of the water source heat exchanger is connected with a water inlet of the high temperature water source tank, wherein in the energy storage process, the compressor unit is started, and the molten salt heat exchanger and the water source heat exchanger on the pipeline at the compressed air outlet of each stage of compressor absorb heat of the compressed air of the stage and store

Assignees

• Xian Thermal Power Res Inst Co
• Univ Northwestern Polytechnical

Inventors

• Jing Xiaolei
• Liu Cunliang
• Lin Yuwen
• Xu Dangqi
• Zhao Liang
• Liang Shuting

Classifications

• F28D2020/0047

  using molten salts or liquid metals · CPC title

• F28D20/0034

  using liquid heat storage material · CPC title

• Y02E60/16

  Mechanical energy storage, e.g. flywheels or pressurised fluids · CPC title

• F02C6/16 Primary

  for storing compressed air · CPC title