Systems and methods for active temperature control in steam turbine

Abstract

Systems and methods for actively controlling the temperature in at least portions of a steam path associated with a steam turbine are disclosed. An active temperature control unit is configured to activate one or more attemperators to maintain temperatures in at least a portion of the steam path below a pre-determined threshold. By maintaining the temperature, those portions of the steam path may use less expensive materials.

The claimed invention is: 
     
         1 . A system, comprising:
 a steam turbine;   one or more attemperators coupled to the steam turbine; and   an active temperature control unit coupled to the one or more attemperators and configured to determine temperature of one or more points associated with the steam turbine and activate at least a portion of the one or more attemperators at least partly in response to the determination.   
     
     
         2 . The system of  claim 1 , wherein the attemperators are configured to inject a coolant into at least a portion of the steam turbine. 
     
     
         3 . The system of  claim 1 , the one or more attemperators disposed within a high pressure section of the steam turbine. 
     
     
         4 . The system of  claim 1 , the one or more attemperators disposed within an intermediate pressure section of the steam turbine. 
     
     
         5 . The system of  claim 1 , the determination of the temperature based at least in part on one or more operating conditions associated with the steam turbine. 
     
     
         6 . The system of  claim 5 , the one or more operating conditions comprising one or more of flow through the steam turbine, output of a heat recovery steam generator coupled to the steam turbine, load condition, or exhaust condition of a gas turbine configured to generate steam for the steam turbine. 
     
     
         7 . The system of  claim 1 , further comprising a temperature sensor proximate to the one or more points and the determination of the temperature based at least in part on a signal from the temperature sensor. 
     
     
         8 . The system of  claim 1 , further comprising cold reheat piping coupled to the steam turbine, and wherein the one or more points include at least a portion of the cold reheat piping. 
     
     
         9 . The system of  claim 1 , wherein the one or more points comprise one or more of a plurality of stages. 
     
     
         10 . A method comprising:
 determining a temperature at one or more pre-determined locations in a steam path of a steam turbine;   when the temperature is at or above a pre-determined threshold, activating one or more attemperators configured to reduce the temperature at least at the one or more pre-determined locations; and   when the temperature is below a pre-determined threshold, deactivating the one or more attemperators.   
     
     
         11 . The method of  claim 10 , the one or more pre-determined locations comprising an exhaust of the steam turbine prior to cold reheat piping. 
     
     
         12 . The method of  claim 10 , the determining the temperature comprising receiving data from one or more temperature sensors. 
     
     
         13 . The method of  claim 10 , the determining the temperature comprising calculating a temperature based at least in part on one or more operating conditions associated with the steam turbine. 
     
     
         14 . The method of  claim 13 , the one or more operating conditions associated with the steam turbine comprising one or more of flow through the steam turbine, output of a heat recovery steam generator coupled to the steam turbine, load condition, or exhaust condition of a gas turbine configured to generate steam for the steam turbine. 
     
     
         15 . The method of  claim 10 , the pre-determined threshold set at or below a design maximum operating temperature for one or more materials proximate to the one or more pre-determined locations in the steam path. 
     
     
         16 . One or more computer-readable media storing computer-executable instructions that, when executed by at least one processor, configure the at least one processor to perform operations comprising:
 receiving indication of a gas turbine turndown from a first power output to a second power output, wherein the second power output is lower than the first power output; and   based at least in part on the indication, activating one or more attemperators in a steam turbine coupled to the gas turbine, the one or more attemperators configured to reduce a temperature in at least a portion of a steam path of the steam turbine.   
     
     
         17 . The computer-readable media of  claim 16 , further comprising deactivating the one or more attemperators when the temperature is at or below a pre-determined threshold. 
     
     
         18 . The computer-readable media of  claim 16 , further comprising monitoring a temperature in at least a portion of the steam path and the activating the one or more attemperators further based at least in part on the temperature. 
     
     
         19 . The computer-readable media of  claim 16 , wherein the steam path comprises cold reheat piping. 
     
     
         20 . The computer-readable media of  claim 16 , wherein the attemperators are configured to inject a coolant into at least a portion of the steam path.