Preheating arrangement for a combined cycle plant

Abstract

A power generation station ( 10 ), including: a combined cycle plant ( 12 ) having a gas turbine engine ( 20 ); a HRSG ( 30 ) configured to receive engine exhaust from the gas turbine engine and to generate steam, and a steam turbine ( 38, 40 ) configured to use the steam to develop mechanical energy; an auxiliary boiler ( 14 ) configured to generate heat used to create auxiliary steam for use in the combined cycle plant and to generate auxiliary boiler exhaust ( 52 ); and an auxiliary boiler exhaust heat transfer arrangement ( 16 ) configured to transfer heat present in the auxiliary boiler exhaust to the combined cycle plant.

The invention claimed is: 
     
         1 . A power generation station, comprising:
 a combined cycle plant comprising a gas turbine engine; a heat recovery steam generator (HRSG) configured to receive engine exhaust from the gas turbine engine and to generate steam, and a steam turbine configured to receive the steam to operate;   an auxiliary boiler configured to generate heat used to create auxiliary steam for use in the combined cycle plant and to generate auxiliary boiler exhaust; and   an auxiliary boiler exhaust heat transfer arrangement configured to transfer heat present in the auxiliary boiler exhaust to the combined cycle plant   
     
     
         2 . The power generation station of  claim 1 , wherein the HRSG is configured to receive the auxiliary boiler exhaust and the heat present therein 
     
     
         3 . The power generation station of  claim 1 , wherein the auxiliary boiler exhaust heat transfer arrangement comprises an auxiliary exhaust heat exchanger configured to receive clean air and to transfer heat from the auxiliary boiler exhaust to the clean air, and wherein the power generation station is configured to deliver clean air heated by the auxiliary exhaust heat exchanger to a component of the combined cycle plant. 
     
     
         4 . The power generation station of  claim 3 , wherein the component comprises at least one of a rotor of the gas turbine engine, a turbine of the gas turbine engine, the HRSG, a catalyst of the HRSG, a superheater of the HRSG, a rotor of the steam turbine, plumbing of the power generation station, a clearance control arrangement for a blade of the gas turbine engine, and a HRSG feedwater heat exchanger configured to receive and heat HRSG feedwater. 
     
     
         5 . The power generation station of  claim 3 , wherein the component comprises the rotor of the gas turbine engine, wherein the auxiliary boiler exhaust heat transfer arrangement further comprises an air source configured to generate the clean air, and wherein the auxiliary boiler exhaust heat transfer arrangement is configured to mix the clean air heated by the auxiliary exhaust heat exchanger with relatively cooler air supplied by the air source. 
     
     
         6 . The power generation station of  claim 5 , wherein the component comprises the turbine of the gas turbine engine, wherein the combined cycle plant further comprises a kettle boiler configured to transfer heat to water used to operate the steam turbine, and wherein the auxiliary boiler exhaust heat transfer arrangement is configured to deliver the heated clean air to the kettle boiler before the clean heated air reaches the turbine of the gas turbine engine 
     
     
         7 . The power generation station of  claim 3 , wherein the auxiliary boiler is configured to receive the heated clean air after the heated clean air is delivered to the component. 
     
     
         8 . The power generation station of  claim 3 , wherein the auxiliary boiler exhaust heat transfer arrangement further comprises an air source configured to generate the clean air, and wherein the air source is configured to receive the heated clean air after the heated clean air is delivered to the component. 
     
     
         9 . The power generation station of  claim 1 , wherein the auxiliary boiler exhaust heat transfer arrangement comprises a HRSG feedwater heat exchanger configured to receive the auxiliary boiler exhaust and to transfer heat from the auxiliary boiler exhaust to HRSG feedwater. 
     
     
         10 . The power generation station of  claim 3 , wherein the auxiliary boiler exhaust heat transfer arrangement further comprises an air source configured to generate the clean air, and wherein the gas turbine engine further comprises a blade clearance control arrangement configured to receive the clean air. 
     
     
         11 . The power generation station of  claim 3 , wherein the auxiliary boiler exhaust heat transfer arrangement further comprises a compressor configured to generate the clean air, wherein the auxiliary boiler is configured to heat feedwater that is preheated by cooling the compressor. 
     
     
         12 . The power generation station of  claim 3 , wherein the auxiliary boiler exhaust heat transfer arrangement further comprises a compressor configured to generate the clean air, wherein the power generation station comprises instrumentation configured to receive the clean air. 
     
     
         13 . In a power generation station comprising a combined cycle plant and an auxiliary boiler configured to generate auxiliary steam used in the combined cycle plant, an improvement comprising:
 an auxiliary boiler exhaust heat transfer arrangement configured to transfer heat present in exhaust from the auxiliary boiler to a component of the combined cycle plant   
     
     
         14 . The power generation station of  claim 13 , wherein the combined cycle plant comprises a heat recovery steam generator (HRSG) configured to receive exhaust from a gas turbine engine,
 wherein the auxiliary boiler exhaust heat transfer arrangement is configured to direct the auxiliary boiler exhaust into the HRSG.   
     
     
         15 . The power generation station of  claim 13 , wherein the auxiliary boiler exhaust heat transfer arrangement comprises an auxiliary exhaust heat exchanger configured to receive clean air and to transfer heat from the auxiliary boiler exhaust to the clean air, and wherein the component of the combined cycle plant is configured to receive the heated clean air. 
     
     
         16 . The power generation station of  claim 15 , wherein the component comprises at least one of a gas turbine engine of the combined cycle plant, a heat recovery steam generator (HRSG) of the combined cycle plant, a steam turbine of the combined cycle plant, plumbing of the power generation station, and a HRSG feedwater heat exchanger configured to receive and heat HRSG feedwater. 
     
     
         17 . The power generation station of  claim 15 , wherein the combined cycle plant further comprises a steam turbine and a kettle boiler configured to transfer heat to water used to operate the steam turbine, and wherein the auxiliary boiler exhaust heat transfer arrangement is configured to deliver the heated clean air to the kettle boiler before the clean heated air reaches the component 
     
     
         18 . The power generation station of  claim 15 , wherein the auxiliary boiler exhaust heat transfer arrangement further comprises an air source configured to generate the clean air, and wherein a gas turbine engine of the combined cycle plant further comprises a blade clearance control arrangement configured to receive the clean air. 
     
     
         19 . The power generation station of  claim 15 , wherein the auxiliary boiler exhaust heat transfer arrangement further comprises an air source configured to generate the clean air, and wherein at least one of the air source and the auxiliary boiler is configured to receive the heated clean air after the heated clean air is delivered to the component. 
     
     
         20 . The power generation station of  claim 15 , wherein the auxiliary boiler exhaust heat transfer arrangement further comprises a compressor configured to generate the clean air, wherein the auxiliary boiler is configured to heat feedwater that is preheated by cooling the compressor.