System and method for high efficiency power generation using a nitrogen gas working fluid

摘要

A method of power production using a high pressure/low pressure ratio Brayton Power cycle with predominantly N2 mixed with CO2 and H2O combustion products as the working fluid is provided. The high pressure can be in the range 80 bar to 500 bar. The pressure ratio can be in the range 1.5 to 10. The natural gas fuel can be burned in a first high pressure combustor with a near stoichiometric quantity of pressurized preheated air and the net combustion gas can be mixed with a heated high pressure recycle N2+CO2+H2O stream which moderates the mixed gas temperature to the value required for the maximum inlet temperature to a first power turbine producing shaft power.

主权项

1. A method for producing power, comprising: combusting a first fuel stream and a first air stream in a first combustor in the presence of a first recycle stream to produce a first combustion stream; expanding the first combustion stream in a first turbine to rotate the first turbine
and produce power; directing at least a portion of a first discharge stream from the first turbine to a first heat exchanger; employing the portion of the first discharge stream to heat the first air stream and at least a portion of the first recycle stream that is produced from the first discharge stream with the first heat exchanger; combusting a second fuel stream and a second air stream in a second combustor in the presence of a second recycle stream that is produced from the first discharge stream to produce a second combustion stream; expanding the second combustion stream in a second turbine to rotate the second turbine to produce power; directing the second air stream and the second recycle stream to a second heat exchanger; heating the second air stream and the second recycle stream with the second heat exchanger; and wherein the first turbine is positioned upstream of the first heat exchanger and the first heat exchanger is positioned upstream of the second turbine in terms of a flow of the first discharge stream.