US 9,435,228 B2 · Air cooling system and method for a heat recovery steam generator inlet

Abstract

The air cooling system and method for a heat recovery steam generator (HRSG) inlet provides a combined cycle power plant utilizing a powerful fan coupled to ductwork connected to pipes that enter the HRSG inlet duct coupled to an exhaust duct of a Combustion Turbine (CT) for lowering the temperature of the CT exhaust gas provided to the heat recovery steam generator by the CT. The cool air injection system is utilized during low load operation or startup of the CT to ensure that spray water from an inter-stage desuperheater in an HRSG is fully evaporated prior to entering the downstream superheater or reheater. A feedback system includes temperature elements measuring the mix temperature that regulates the cooling air injection rate into the HRSG inlet.

Claims4

Dependent claims

An air cooling method for a heat recovery steam generator having inter-stage attemperators and a heat recovery steam generator exhaust gas inlet accepting flow of exhaust gas from a combustion turbine, the method comprising the steps of:

beginning cooling air flow when output in megawatts from the combustion turbine is greater than 20% of full load and a combustion turbine steam set point is increasing, the cooling air flow injecting a cooling air into the combustion turbine exhaust or the heat recovery steam generator exhaust gas inlet;
and
terminating the cooling air flow when the combustion turbine output in megawatts is greater than 80% of full load or heat recovery steam generator exhaust gas inlet temperature is less than the steam set point plus 50° F.

Dependencies are inferred from the claim text.

Facts

Application

14/248,887Filed 9 Apr 2014 · continuation

Priority

4 Feb 2011

Published

US 2014/0216001 A17 Aug 2014

Granted

6 Sep 2016

Term ends

Not estimatedThe source records don’t support an estimate.

Classification10 codes

F01K 23/101
With exhaust fluid of one cycle heating the fluid in another cycle: regulating means specially adapted therefor
F01K 23/10
Combustion heat from one cycle heating the fluid in another cycle: with exhaust fluid of one cycle heating the fluid in another cycle
F22B 1/1815
Using the exhaust gases of combustion engines: using the exhaust gases of gas-turbines
F22B 35/007
Control systems for steam boilers: control systems for waste heat boilers

Air cooling system and method for a heat recovery steam generator inlet

Life of this patent

Air cooling system and method for a heat recovery steam generator inlet

Life of this patent

Abstract

Claims4