Compressed air energy storage system utilizing two-phase flow to facilitate heat exchange

Abstract

A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

What is claimed is: 
     
         1 . An apparatus comprising:
 an expander comprising a first chamber in fluid communication with a compressed gas storage unit;   a first moveable member received within the first chamber;   a first mechanical linkage configured to transmit out of the first chamber, a power of gas expanding against the first moveable member; and   a multi-node gearing system configured to combine the power of the first mechanical linkage with an output of an energy source.   
     
     
         2 . An apparatus as in  claim 1  wherein the expander comprises a compressor/expander, and the multi-node gearing system is configured to selectively drive the first mechanical linkage to compress gas within the chamber. 
     
     
         3 . An apparatus as in  claim 2  further comprising a first element to effect gas-liquid heat exchange with gas in the first chamber. 
     
     
         4 . An apparatus as in  claim 3  wherein the first moveable member is configured to reciprocate within the first chamber. 
     
     
         5 . An apparatus as in  claim 3  wherein the first moveable member is configured to rotate within the first chamber. 
     
     
         6 . An apparatus as in  claim 1  wherein the expander comprises a dedicated expander, and the apparatus further comprises:
 a dedicated compressor comprising a second chamber in fluid communication with the compressed gas storage unit; 
 a second moveable member received within the second chamber; and 
 a second mechanical linkage in communication with the multi-node gearing system to transmit into the second chamber, a power to drive the second moveable member to compress gas. 
 
     
     
         7 . An apparatus as in  claim 6  further comprising:
 a first element configured to effect gas-liquid heat exchange with the expanding gas in the first chamber; 
 a second element configured to effect gas-liquid heat exchange with gas compressed in the second chamber. 
 
     
     
         8 . An apparatus as in  claim 6  wherein the second moveable member is configured to reciprocate within the second chamber. 
     
     
         9 . An apparatus as in  claim 6  wherein the second moveable member is configured to rotate within the second chamber. 
     
     
         10 . An apparatus as in  claim 1  wherein the multi-node gearing system comprises a planetary gear. 
     
     
         11 . An apparatus as in  claim 1  wherein:
 first moveable member comprises a piston; 
 the first mechanical linkage comprises a piston rod and a rotating shaft; and 
 the energy source comprises a source of shaft torque. 
 
     
     
         12 . An apparatus as in  claim 11  wherein the source of shaft torque comprises a generation asset. 
     
     
         13 . An apparatus as in  claim 12  wherein the generation asset is renewable. 
     
     
         14 . An apparatus as in  claim 13  wherein the generation asset comprises a wind turbine. 
     
     
         15 . An apparatus as in  claim 12  wherein the generation asset is dispatchable. 
     
     
         16 . An apparatus as in  claim 15  wherein the generation asset comprises a turbine. 
     
     
         17 . An apparatus as in  claim 12  wherein the turbine comprises a natural gas turbine. 
     
     
         18 . An apparatus as in  claim 11  wherein the source of shaft torque comprises a motor. 
     
     
         19 . An apparatus as in  claim 18  wherein the motor comprises a combustion motor.