Advanced adiabatic compressed air energy storage system

Abstract

A compressed air energy storage (CAES) system is disclosed for the generation of power. The system may include a compressor configured to receive inlet air and output compressed air to an air storage during an off-peak period. During a peak load period, compressed air from the air storage may be released to generate power. A heat exchanger fluidly coupled to the air storage may receive the released compressed air and transfer heat to the compressed air. An air expander may receive the heated compressed air from the heat exchanger, expand the heated compressed air to generate a first power output, and output an exhaust. The system may further include a bypass line configured to circumvent compressed air around the air expander. A second power output may be generated through a turbine configured to receive the compressed air from the air storage and the exhaust from the air expander.

We claim: 
     
         1 . A compressed air energy storage power generation system comprising:
 a compressor configured to receive inlet air and output compressed air;   an air storage fluidly coupled to the compressor and defining a volume configured to store the compressed air from the compressor;   a heat exchanger fluidly coupled to the air storage via a feed line and configured to receive the compressed air from the air storage and transfer heat from a heat source to the compressed air;   an air expander fluidly coupled to the heat exchanger via the feed line and configured to receive the heated compressed air from the heat exchanger, expand the heated compressed air to generate a first power output in an electric generator coupled to the air expander, and output an exhaust;   a bypass line fluidly coupled to the feed line upstream of the air expander and downstream from the air expander, and configured to circumvent the compressed air around the air expander; and   a turbine fluidly coupled to the air expander and the air storage and configured to receive the compressed air from the air storage and the exhaust from the air expander.   
     
     
         2 . The system of  claim 1 , wherein the turbine comprises a plurality of gas turbines, each coupled to a combustor. 
     
     
         3 . The system of  claim 1 , further comprising a valve assembly including one or more valves configured to control a total mass flow of the compressed air output from the compressor to the turbine. 
     
     
         4 . The system of  claim 3 , wherein the one or more valves includes a bypass control valve fluidly coupling the feed line and the bypass line and configured to control a distribution of the total mass flow of the compressed air between the feed line and the bypass line. 
     
     
         5 . The system of  claim 4 , wherein the one or more valves further comprises a control valve disposed downstream from the air storage. 
     
     
         6 . The system of  claim 1 , wherein the air expander includes a plurality of stages and the heated compressed air is expanded through at least one of the plurality of stages. 
     
     
         7 . The system of  claim 4 , wherein the total mass flow of the compressed air directed to the turbine has flow parameters consistent with injection flow parameters of the turbine. 
     
     
         8 . The system of  claim 1 , wherein the heat source is provided by a combustion turbine assembly. 
     
     
         9 . The system of  claim 1 , wherein the compressed air from the compressor is converted into liquid air before being directed to the air storage. 
     
     
         10 . A method of operating a compressed air energy storage system having a compressor, an air storage fluidly coupled to the compressor, a heat exchanger fluidly coupled to the air storage via a feed line, an air expander fluidly coupled to the heat exchanger via the feed line, a bypass line fluidly coupled to the feed line upstream of the air expander and downstream from the air expander, and a turbine fluidly coupled to the air expander and the air storage, the method comprising:
 compressing inlet air in the compressor and storing the compressed air in the air storage during an off-peak period;   releasing the compressed air from the air storage during a peak load period;   heating a first portion of the compressed air from the air storage in the heat exchanger with heat from a heat source;   directing the first portion of the heated compressed air from the heat exchanger to the air expander and expanding the first portion of the heated compressed air therein to produce a first power output and an exhaust;   directing a second portion of the compressed air from the air storage through the bypass line to the turbine, thereby circumventing the air expander; and   expanding the exhaust from the air expander and the second portion of the compressed air from the bypass line in the turbine to generate a second power output.   
     
     
         11 . The method of  claim 10 , wherein the air expander includes a plurality of stages, and the method further comprises expanding the heated compressed air through at least one of the plurality of stages of the air expander. 
     
     
         12 . The method of  claim 10 , further comprising converting the compressed air into liquid air before storing the liquid air in the air storage during the off-peak period. 
     
     
         13 . The method of  claim 10 , further comprising controlling a total mass flow of the compressed air output from the compressor to the turbine with a valve assembly including one or more valves. 
     
     
         14 . The method of  claim 13 , wherein:
 the one or more valves includes a bypass control valve fluidly coupling the feed line and the bypass line; and   controlling the total mass flow includes actuating the bypass control valve to control a distribution of the total mass flow between the feed line and the bypass line.   
     
     
         15 . The method of  claim 14 , further comprising matching flow parameters of the total mass flow with injection flow parameters of the turbine. 
     
     
         16 . The method of  claim 15 , wherein:
 a pressure of the compressed air in the air storage is greater than a design inlet parameter for the air expander; and   matching the flow parameters includes actuating the bypass control valve to allow all or substantially all the compressed air to flow through the air expander.   
     
     
         17 . The method of  claim 15 , wherein:
 a pressure of the compressed air in the air storage is less than a design inlet parameter for the air expander and greater than the injection flow parameters for the turbine; and   matching the flow parameters includes actuating the bypass control valve to control the flow of the second portion of compressed air through the bypass line.   
     
     
         18 . The method of  claim 14 , wherein the compressed air directed to the turbine is provided by the compressor, and controlling the total mass flow includes actuating the bypass control valve to allow all or substantially all the compressed air to flow through the bypass line, thereby bypassing the air expander and providing the compressed air directly to the turbine. 
     
     
         19 . The method of  claim 14 , further comprising cooling the air expander. 
     
     
         20 . The method of  claim 19 , wherein cooling the air expander includes actuating the bypass control valve to control the flow of the first portion of compressed air through the air expander.