Pumped air storage peaking power system using a single shaft gas turbine-generator unit

Claim 2

A pumped air storage peaking power system comprising: a conventional single shaft gas turbine engine of the type having a compressor and an axially spaced turbine rigidly connected to a rotatable shaft, said gas turbine engine including a combustor for receiving pressurized air and fuel for generation of a hot gas stream for driving said turbine; a dynamoelectric machine directly and rigidly connected to said gas turbine engine shaft, said dynamoelectric machine adapted to be driven by said engine shaft and generate electrical power in a first mode of operation, and to receive electrical power and drive said engine shaft in a second mode of operation; an air storage reservoir, having an inlet and an outlet, for receiving, storing and dispensing compressed air; first valve means for communicating compressed air from said compressor with said air storage reservoir inlet when said dynamoelectric machine is operating in said second mode and for closing said communication when said dynamoelectric machine is operating in said first mode; second valve means for communicating compressed air from said storage reservoir outlet with said combustor when said dynamoelectric machine is operating in said first mode, and for closing said communication when said dynamoelectric machine is operating in said second mode; and throttling valve means for restricting air flow to said compressor when said dynamoelectric machine is operating in said first mode; whereby windage losses in the compressor are sufficiently reduced when said dynamoelectric machine is operating in said first mode to enable a conventional gas turbine to be effectively employed in the air storage system.

Claim 3

The pumped air storage peaking power system of claim 1 further characterized by and including means for generating steam and fourth valve means associated therewith for delivering said steam to said turbine when said dynamoelectric machine is operating in said second mode to thereby reduce turbine windage losses.

Claim 4

The pumped air storage peaking power system of claim 2 wherein said means for generating steam comprise a heat exchanger disposed between said compressor and said air storage reservoir.

Claim 5

A pumped air storage peaking power system comprising: a single shaft gas turbine having a compressor and a turbine both directly connected to a dynamoelectric machine through rotatable shaft means, first throttling valve means in communication with said compressor, said first valve operable to selectively throttle air flow to said compressor, an air reservoir in communication with said compressor for receiving and storing compressed air from said compressor, a first heat exchanger in communication with said compressor and said reservoir, compressed air passing to said reservoir from said compressor being cooled by first passing through said heat exchanger to release heat, a combustor in communication with said turbine, said combustor combining fuel and compressed air supplied by the compressor to produce gaseous combustion products which are conveyed to said turbine to drive it, second and third valves, said second valve being in communication with said air compressor, said air reservoir and said third valve, compressed air exiting from said compressor being directed by said second valve selectively to either said reservoir or to said third valve, said third valve also being in communication with said combustor, said compressed air passing to said third valve being selectively directed thereby either into said combustor or to a region of substantially atmospheric pressure, a fourth valve disposed in communication with said reservoir and said combustor, said fourth valve selectively controlling passage of compressed air from said reservoir to said combustor; a second heat exchanger in communication with said compressor, said combustor and said turbine, compressed air directed to said combustor from said compressor first passing through said second heat exchanger for preheating, gaseous combustion products discharged from said turbine being directed through said second heat exchanger to supply heat to said compressed air; and means for conducting water through said first heat exchanger in heat exchange relation with said compressed air to cause conversion of said water to steam and also comprising a fifth valve in communication with said first heat exchanger to selectively control passage of steam from said first heat exchanger into said turbine.

Claim 6

A pumped air storage peaking power system comprising: a single shaft gas turbine having a compressor and a turbine both directly connected to a dynamoelectric machine through rotatable shaft means, first throttling valve means in communication with said compressor, said first valve operable to selectively throttle air flow to said compressor, an air reservoir in communication with said compressor for receiving and storing compressed air from said compressor, a first heat exchanger in communication with said compressor and said reservoir, compressed air passing to said reservoir from said compressor being cooled by first passing through said heat exchanger to release heat, a combustor in communication with said turbine, said combustor combining fuel and compressed air supplied by the compressor to produce gaseous combustion products which are conveyed to said turbine to drive it, second and third valves, said second valve being in communication with said air compressor, said air reservoir and said third valve, compressed air exiting from said compressor being directed by said second valve selectively to either said reservoir or to said third valve, said third valve also being in communication with said combustor, said compressed air passing to said third valve being selectively directed thereby either into said combustor or to a region of substantially atmospheric pressure, a fourth valve disposed in communication with said reservoir and said combustor, said fourth valve selectively controlling passage of compressed air from said reservoir to said combustor; a second heat exchanger in communication with said compressor, said combustor and said turbine, compressed air directed to said combustor from said compressor first passing through said second heat exchanger for preheating, gaseous combustion products discharged from said turbine being directed through said second heat exchanger to supply heat to said compressed air; and means for conducting water through said first heat exchanger in heat exchange relation with said compressed air to cause conversion of said water to steam and also comprising a fifth valve in communication with said first heat exchanger to selectively control passage of steam from said first heat exchanger into said turbine.

Claim 7

The system of claim 4 wherein: a. when said system is operating as a peaking power system said first valve is set to throttle air flow to said compressor and said fourth valve is open to supply compressed air from said reservoir to said combustor, gaseous combustion product from said combustors being directed to said turbine, b. when said system is operating as a conventional gas turbine unit, said first valve is set in its fully open position and said fourth valve is closed, and said second and third valves are set to direct compressed air from said compressor to said combustor, gaseous combustion product from said combustor being directed to said turbine, and c. when said system is operating as an air compressor, said second valve is set to direct air to said reservoir and said fourth valve is closed.