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 power production system, comprising:
a first combustor configured to combust a first fuel stream and a first air stream in the presence of a first recycle stream to produce a first combustion stream; a first turbine configured to expand the first combustion stream; a first heat exchanger configured to receive at least a portion of a first discharge stream from the first turbine,
wherein the first heat exchanger is configured to employ 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; a second combustor configured to combust a second fuel stream and a second air stream in the presence of a second recycle stream that is produced from the first discharge stream to produce a second combustion stream; a second turbine configured to expand the second combustion stream; and a second heat exchanger configured to heat the second air stream and the second recycle stream, 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.