Gas turbine and method to operate the gas turbine

Abstract

It is proposed a gas turbine and a method to operate the gas turbine. A fluid is supplied to the gas turbine by means of fluid paths. A first fluid path is divided into a second and third fluid path. A first control valve controls a fluid mass flow in the first fluid path. A second control valve controls a ratio of fluid mass flows in the second and third fluid paths.

1 . A gas turbine, wherein a fluid is supplied to the gas turbine by means of fluid paths, wherein a first fluid path is divided into a second and third fluid path in a flow direction of the fluid, wherein a first control valve controls a fluid mass flow in the first fluid path, and wherein a second control valve controls a ratio of fluid mass flows in the second and third fluid paths. 
     
     
         2 . The gas turbine according to  claim 1 , wherein a first hydraulic diameter of the first fluid path is adjustable by means of the first control valve, wherein a second hydraulic diameter of the second fluid path is adjustable by means of the second control valve, and wherein a third hydraulic diameter of the third fluid path is fixed. 
     
     
         3 . The gas turbine according to  claim 1 , wherein a shut off valve is arranged in series with the first control valve, and wherein the first control valve provides a shut off capability. 
     
     
         4 . The gas turbine according to  claim 1 , wherein a fourth fluid path is divided into a fifth and sixth fluid path in a flow direction of the fluid, wherein a third control valve controls a fluid mass flow in the fourth fluid path, wherein a fourth control valve controls a ratio of the mass flows in the fifth and sixth paths, wherein a fourth hydraulic diameter of the fourth fluid path is adjustable by means of the third control valve, wherein a fifth hydraulic diameter of the fifth fluid path is adjustable by means of the fourth control valve, and wherein a sixth hydraulic diameter of the sixth fluid path is fixed. 
     
     
         5 . The gas turbine according to  claim 4 , wherein the first and fourth fluid paths are connected to the same fluid source. 
     
     
         6 . The gas turbine according to  claim 2 , wherein the maximum of the second hydraulic diameter is smaller than the third hydraulic diameter. 
     
     
         7 . The gas turbine according to  claim 1 , wherein the second fluid path supplies a first stage of fluid outlets, and wherein the third fluid path supplies a second stage of fluid outlets, and wherein the first and second stage are attached to at least one of the burners or the first and second stage are attached to at least two different burners, respectively; and/or wherein the fifth fluid path supplies a third stage of fluid outlets, and wherein the sixth fluid path supplies a fourth stage of fluid outlets, and wherein the third and fourth stage are attached to at least one of the burners or the third and fourth stage are attached to at least two different burners, respectively. 
     
     
         8 . The gas turbine according to  claim 1 , wherein the second and/or fourth path is connected to a fewer number of fluid outlets, than the third and/or sixth path. 
     
     
         9 . A method to operate a gas turbine, wherein a fluid is supplied to the gas turbine by means of fluid paths, wherein a first fluid path is divided into a second and third fluid path in a flow direction of the fluid, wherein a first control valve controls a fluid mass flow in the first fluid path, and wherein a second control valve controls a ratio of fluid mass flows in the second and third fluid paths. 
     
     
         10 . The method according to  claim 9 , wherein a first hydraulic diameter of the first fluid path is adjustable by means of the first control valve, wherein a second hydraulic diameter of the second fluid path is adjustable by means of the second control valve, and wherein a third hydraulic diameter of the third fluid path is fixed. 
     
     
         11 . The method according to  claim 10 , wherein the first hydraulic diameter is adjusted in a first time interval, especially corresponding to a transient state of the gas turbine, while the second hydraulic diameter is maintained at a fixed value, and wherein the second hydraulic diameter is adjusted in a second time interval, especially corresponding to a steady state of the gas turbine, while the first hydraulic diameter is maintained at a fixed value. 
     
     
         12 . The method according to  claim 10 , wherein the first hydraulic diameter is affected by means of the first control valve controlled by a first closed-loop controller, wherein the second hydraulic diameter is affected by means of the second control valve controlled by a second closed-loop controller, and wherein a bandwidth of a first control loop comprising the first closed-loop controller is greater than a bandwidth of a second control loop comprising the second closed-loop controller. 
     
     
         13 . The method according to  claim 10 , wherein the second hydraulic diameter is affected in a steady state of the gas turbine by means of the second control valve controlled by a second closed-loop controller, and wherein the second hydraulic diameter is affected in a transient state of the gas turbine by means of the second control valve controlled by a feed forward controller. 
     
     
         14 . The method according to  claim 12 , wherein a process variable of the first closed-loop controller is a pressure difference between a pressure before the first control valve and a pressure behind the first control valve and/or a fluid temperature of fluid in the first path and/or a total fluid mass rate through the first path, and/or wherein a process variable of the second closed-loop controller is a pressure difference between a pressure before the second control valve and a pressure behind the second control valve and/or an emission of the gas turbine, especially a ratio of nitrogen oxides, of carbon monoxide or of unburned hydrocarbons in the emissions, and/or a flame stability criteria. 
     
     
         15 . Control unit for operating a gas turbine with a digital computation unit for executing a computer program which is adapted to perform a method according to  claim 9 .