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

摘要

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.

主权项

1. A method comprising:
introducing a first quantity of air at a first temperature into a first chamber; in a compression cycle, subjecting the first quantity of air to compression by a first piston coupled to the first chamber; injecting a first determined quantity of fluid into the first quantity of air to absorb thermal energy generated by the compression cycle and thereby maintain the first quantity of air in a first temperature range during the compression; and transferring at least a portion of the first quantity of air to a storage unit, the method further comprising: in an expansion cycle, transferring a second quantity of air from the storage unit to the first chamber through valving under electronic control; allowing the second quantity of air to expand and drive the first piston; and injecting a second determined quantity of fluid into the second quantity of air to provide thermal energy absorbed by the expanding air and thereby maintain the second quantity of air in a second temperature range during the expansion, wherein a valve timing is adjusted dynamically as the storage unit depletes.