System and method for managing heat recovery steam generator inlet temperature

Abstract

A system may include a gas turbine system. The gas turbine system may include a compressor, such that the gas turbine system may produce exhaust gas in an exhaust outlet when generating electricity. The system may also include a heat recovery steam generator (HRSG) that may use the exhaust gas to create steam, a manifold system configured to couple compressed air in the compressor to the exhaust outlet, and a controller configured to send a command to the manifold system to couple the compressed air to the exhaust outlet when a temperature of the exhaust gas is above a threshold.

1 . A system comprising:
 a gas turbine system comprising a compressor, wherein the gas turbine system is configured to produce exhaust gas in an exhaust outlet when generating electricity;   a heat recovery steam generator (HRSG) configured to use the exhaust gas to create steam;   a manifold system configured to couple compressed air in the compressor to the exhaust outlet; and   a controller configured to send a command to the manifold system to couple the compressed air to the exhaust outlet when a temperature of the exhaust gas is above a threshold.   
     
     
         2 . The system of  claim 1 , comprising a steam turbine system configured to receive the steam. 
     
     
         3 . The system of  claim 1 , wherein the controller is configured to model the temperature of the exhaust gas based on a mass flow of the compressed air, a mass flow of the exhaust gas, a temperature of the compressed air, a temperature of the exhaust gas, or any combination thereof. 
     
     
         4 . The system of  claim 3 , wherein the mass flow of the compressed air is determined based on a pressure sensor measurement received via a differential pressure sensor associated with the compressed air. 
     
     
         5 . The system of  claim 3 , wherein the mass flow of the exhaust gas is determined based on known gas turbine system parameters. 
     
     
         6 . The system of  claim 1 , wherein the temperature of the compressed air or the temperature of the exhaust gas is acquired via a temperature sensor. 
     
     
         7 . The system of  claim 1 , wherein the compressor comprises a compressor discharge chamber, wherein the compressed air is coupled to the exhaust outlet via the compressor discharge chamber . 
     
     
         8 . The system of  claim 1 , wherein the manifold system comprises one or more valves configured to direct at least a portion of the compressed air to the exhaust outlet. 
     
     
         9 . The system of  claim 1 , wherein the threshold is associated with an operating range of the HSRG. 
     
     
         10 . A non-transitory machine readable medium, comprising computer-executable instructions configured to cause a processor to:
 monitor a temperature of exhaust gas provided to a heat recovery steam generator (HSRG) via an exhaust outlet; and   send a command to a manifold system when the temperature exceeds a threshold, wherein the command is configured to cause the manifold system to couple compressed air to the exhaust outlet.   
     
     
         11 . The non-transitory machine readable medium of  claim 10 , wherein the computer-executable instructions to cause the processor to monitor the temperature comprises instructions to cause the processor to receive the temperature via a temperature sensor associated with the exhaust outlet. 
     
     
         12 . The non-transitory machine readable medium of  claim 10 , wherein the computer-executable instructions to cause the processor to monitor the temperature comprises instructions to cause the processor to model the temperature of the exhaust outlet based on a mass flow of the compressed air, a mass flow of the exhaust gas, a temperature of the compressed air, a temperature of the exhaust gas, or any combination thereof. 
     
     
         13 . The non-transitory machine readable medium of  claim 12 , wherein the mass flow of the compressed air is determined based on a pressure sensor measurement received via a differential pressure sensor associated with the compressed air. 
     
     
         14 . The non-transitory machine readable medium of  claim 12 , wherein the mass flow of the exhaust gas is determined based on known gas turbine system parameters. 
     
     
         15 . The non-transitory machine readable medium of  claim 10 , wherein the threshold is associated with an operating range of the HSRG. 
     
     
         16 . A manifold system, comprising:
 one or more valves configured to couple compressed air from a compressor of a gas-turbine system to an exhaust outlet of the gas-turbine system, wherein the exhaust outlet is configured to provide exhaust gas to a heat recovery steam generator (HSRG); and   a control system configured to adjust the one or more valves to couple the compressed air to the exhaust outlet when a temperature of the exhaust gas is above a threshold.   
     
     
         17 . The manifold system of  claim 16 , wherein at least one of the one or more valves is coupled to a compressor discharge chamber of the compressor. 
     
     
         18 . The manifold system of  claim 16 , wherein at least one of the one or more valves is coupled to an inlet bleed heat system associated with the gas-turbine system. 
     
     
         19 . The manifold system of  claim 16 , wherein the threshold is associated with an operating range of the HSRG. 
     
     
         20 . The manifold system of  claim 16 , wherein the control system is configured to adjust the one or more valves to decouple the compressed air from the exhaust outlet after the temperature of the exhaust gas returns to below the threshold.