Gas turbine emissions control system and method

Abstract

Embodiments of the present disclosure are directed towards a system including a gas turbine engine, a selective catalytic reduction system, and a control system configured to regulate operation of the selective catalytic reduction system based at least partially on preset variations in an emissions compound of exhaust gases produced by the gas turbine engine.

1 . A system, comprising:
 a gas turbine engine;   a selective catalytic reduction system; and   a control system configured to regulate operation of the selective catalytic reduction system based at least partially on preset variations in an emissions compound of exhaust gases produced by the gas turbine engine.   
     
     
         2 . The system of  claim 1 , wherein the preset variations are scheduled variations, and the scheduled variations include a first level of the emissions compound for a first period of time and a second level of the emissions compound for a second period of time. 
     
     
         3 . The system of  claim 1 , wherein the control system is configured to regulate an amount of a reductant injected into the selective catalytic reduction system based at least partially on the preset variations in the emissions compound of the exhaust gases produced by the gas turbine engine. 
     
     
         4 . The system of  claim 3 , wherein the reductant is ammonia. 
     
     
         5 . The system of  claim 1 , wherein the control system is further configured to regulate operation of the selective catalytic reduction system based at least partially on a permitted level of the emissions compound in processed exhaust gases produced by the selective catalytic reduction system. 
     
     
         6 . The system of  claim 1 , wherein the controller comprises a gas turbine engine controller configured to achieve the preset variations in the emissions compound of exhaust gases produced by the gas turbine engine by regulating one or more operating parameters of the gas turbine engine. 
     
     
         7 . The system of  claim 6 , wherein the one or more operating parameters comprises a fuel split of a combustor of the gas turbine engine, a water injection of the combustor, a flame temperature of the combustor, an air-fuel ratio of the combustor, or a combination thereof. 
     
     
         8 . A method of operating a turbine system, comprising:
 operating a gas turbine engine of the turbine system at less than full load;   increasing an emissions compound in an exhaust gas produced by the gas turbine engine;   utilizing available capacity of a selective catalytic reduction system of the turbine system to reduce the emissions compound in the exhaust gas to produce a processed exhaust gas.   
     
     
         9 . The method of  claim 8 , wherein increasing the emissions compound in the exhaust gas comprises reducing water or steam injection into a combustor of the gas turbine engine. 
     
     
         10 . The method of  claim 8 , wherein increasing the emissions compound in the exhaust gas comprises increasing a flame temperature within a combustor of the gas turbine engine. 
     
     
         11 . The method of  claim 8 , wherein increasing the emissions compound in the exhaust gas comprises adjusting a fuel split into a combustor of the gas turbine engine or adjusting a fuel-air ratio of the combustor. 
     
     
         12 . The method of  claim 8 , wherein utilizing available capacity of the selective catalytic reduction system comprises regulating injection of a reductant into the selective catalytic reduction system. 
     
     
         13 . The system of  claim 12 , comprising regulating injection of the reductant into the selective catalytic reduction system based at least partially on a measured amount of unreacted reductant in the selective catalytic reduction system. 
     
     
         14 . The system of  claim 12 , comprising regulating injection of the reductant into the selective catalytic reduction system based at least partially on a measurement of the emissions compound in the processed exhaust gas. 
     
     
         15 . A method of operating a turbine system, comprising:
 scheduling variations in a first amount of an emissions compound in exhaust gas produced by a gas turbine engine of the turbine system;   regulating operation of a selective catalytic reduction system of the turbine system to achieve a second amount of the emissions compound in a processed exhaust gas produced by the selective catalytic reduction system based at least partially on the variations in the first amount of the emissions compound in an exhaust gas produced by the gas turbine engine of the turbine system.   
     
     
         16 . The method of  claim 15 , wherein regulating operation of the selective catalytic reduction system of the turbine system to achieve a second amount of the emissions compound in the processed exhaust gas produced by the selective catalytic reduction system comprises regulating a third amount of a reductant injected into the selective catalytic reduction system. 
     
     
         17 . The method of  claim 16 , wherein regulating the third amount of the reductant injected into the selective catalytic reduction system comprises measuring a fourth amount of unreacted reductant in the selective catalytic reduction system and adjusting the third amount based on the fourth amount. 
     
     
         18 . The method of  claim 15 , comprising adjusting one or more operating parameters of the gas turbine engine to achieve the variations in the first amount of the emissions compound in the exhaust gas produced by the gas turbine engine of the turbine system. 
     
     
         19 . The method of  claim 18 , wherein adjusting one or more operating parameters of the gas turbine engine to achieve the variations in the first amount of the emissions compound in the exhaust gas produced by the gas turbine engine of the turbine system comprises reducing a water or steam injection into a combustor of the gas turbine engine. 
     
     
         20 . The method of  claim 18 , wherein adjusting one or more operating parameters of the gas turbine engine to achieve the variations in the first amount of the emissions compound in the exhaust gas produced by the gas turbine engine of the turbine system comprises regulating combustion fuel splits of a combustor of the gas turbine engine.