System and method for load control with diffusion combustion in a stoichiometric exhaust gas recirculation gas turbine system

Abstract

A system is provided with a turbine combustor having a first diffusion fuel nozzle, wherein the first diffusion fuel nozzle is configured to produce a diffusion flame. The system includes a turbine driven by combustion products from the diffusion flame in the turbine combustor. The system also includes an exhaust gas compressor, wherein the exhaust gas compressor is configured to compress and route an exhaust gas from the turbine to the turbine combustor along an exhaust recirculation path. In addition, the system includes a control system configured to control flow rates of at least one oxidant and at least one fuel to the turbine combustor in a stoichiometric control mode and a non-stoichiometric control mode, wherein the stoichiometric control mode is configured to change the flow rates and provide a substantially stoichiometric ratio of the at least one fuel with the at least one oxidant, and the non-stoichiometric control mode is configured to change the flow rates and provide a non-stoichiometric ratio of the at least one fuel with the at least one oxidant.

1 . A system, comprising:
 a turbine combustor, comprising:
 a chamber; and 
 a diffusion nozzle comprising a first passage configured to inject a first flow of a fuel into the chamber, a second passage configured to inject a second flow of an oxidant into the chamber, and a third passage configured to inject a third flow of a diluent into the chamber, wherein the first passage, the second passage, and the third passage are fluidly isolated from each other along the diffusion nozzle; 
   a turbine configured to be driven by combustion products generated from a diffusion flame produced by the turbine combustor, wherein the turbine is configured to output an exhaust gas;   an exhaust gas compressor configured to compress the exhaust gas and route the exhaust gas from the turbine, along an exhaust recirculation path, and to the turbine combustor such that the exhaust gas forms at least a portion of the third flow of the diluent; and   a control system configured to control a first flow rate of the first flow, a second flow rate of the second flow, a third flow rate of the third flow, or any combination thereof based on a load of the system.   
     
     
         2 . The system of  claim 1 , wherein the control system is configured to reduce the first flow rate of the first flow, the second flow rate of the second flow, the third flow rate of the third flow, or any combination thereof based on the load of the system changing from a first load to a second load. 
     
     
         3 . The system of  claim 1 , wherein the control system is configured to increase the first flow rate of the first flow, the second flow rate of the second flow, the third flow rate of the third flow, or any combination thereof based on the load of the system changing from a first load to a second load. 
     
     
         4 . The system of  claim 1 , wherein the control system is configured to control the first flow rate of the first flow, the second flow rate of the second flow, the third flow rate of the third flow, or any combination thereof based on the load of the system and such that a stoichiometric ratio is maintained while the load corresponds to a full load and while the load corresponds to a partial load, wherein the stoichiometric ratio corresponds to an equivalence ratio between 0.95 and 1.05. 
     
     
         5 . The system of  claim 1 , wherein the second passage is configured to inject the second flow of a mixture of the oxidant and an additional diluent into the chamber. 
     
     
         6 . The system of  claim 1 , wherein the diffusion nozzle comprises a fourth passage configured to inject a fourth flow of an additional fuel, an additional oxidant, or an additional diluent into the chamber, wherein the fourth passage is fluidly isolated from the first passage, the second passage, and the third passage along the diffusion nozzle. 
     
     
         7 . The system of  claim 1 , comprising an additional diffusion nozzle comprising a fourth passage configured to inject a fourth flow of an additional fuel into the chamber, a fifth passage configured to inject a fifth flow of an additional oxidant into the chamber, and a sixth passage configured to inject a sixth flow of an additional diluent into the chamber, wherein the fourth passage, the fifth passage, and the sixth passage are fluidly isolated from each other along the additional diffusion nozzle. 
     
     
         8 . The system of  claim 7 , wherein the control system is configured to control a fourth flow rate of the fourth flow, a fifth flow rate of the fifth flow, a sixth flow rate of the sixth flow, or any combination thereof based on the load of the system. 
     
     
         9 . The system of  claim 7 , wherein the control system is configured to control the diffusion nozzle and the additional diffusion nozzle such that a stoichiometric ratio is maintained while the load corresponds to a full load and while the load corresponds to a partial load, wherein the stoichiometric ratio corresponds to an equivalence ratio between 0.95 and 1.05. 
     
     
         10 . The system of  claim 1 , comprising at least one valve or pump, wherein the control system is configured to control the first flow rate of the first flow, the second flow rate of the second flow, the third flow rate of the third flow, or any combination thereof based on the load of the system by controlling the at least one valve or pump. 
     
     
         11 . A system, comprising:
 a turbine combustor, comprising:
 a chamber; and 
 a diffusion nozzle comprising a first passage configured to inject a fuel into the chamber, a second passage configured to inject an oxidant into the chamber, and a third passage configured to inject a diluent into the chamber, wherein the first passage, the second passage, and the third passage are fluidly isolated from each other along the diffusion nozzle; 
   a turbine configured to be driven by combustion products generated from a diffusion flame produced by the turbine combustor, wherein the turbine is configured to output an exhaust gas;   an exhaust gas compressor configured to compress the exhaust gas and route the exhaust gas from the turbine, along an exhaust recirculation path, and to the turbine combustor such that the exhaust gas forms at least a portion of the diluent; and   a control system configured to control the system such that:
 the fuel is moved through the first passage at a first flow rate based on the system being operated at a full load, and the fuel is moved through the first passage at a second flow rate based on the system being operated at a partial load, wherein the second flow rate differs from the first flow rate; or 
 the oxidant is moved through the second passage at a third flow rate based on the system being operated at the full load, and the oxidant is moved through the second passage at a fourth flow rate based on the system being operated at the partial load, wherein the fourth flow rate differs from the third flow rate; or 
 the diluent is moved through the third passage at a fifth flow rate based on the system being operated at the full load, and the diluent is moved through the third passage at a sixth flow rate based on the system being operated at the partial load, wherein the sixth flow rate differs from the fifth flow rate; or 
 any combination thereof. 
   
     
     
         12 . The system of  claim 11 , wherein the control system is configured to maintain a stoichiometric ratio while the system is being operated at the full load and while the system is being operated at the partial load, wherein the stoichiometric ratio corresponds to an equivalence ratio between 0.95 and 1.05. 
     
     
         13 . The system of  claim 11 , comprising an additional diffusion nozzle comprising a fourth passage configured to inject an additional fuel into the chamber, a fifth passage configured to inject an additional oxidant into the chamber, and a sixth passage configured to inject an additional diluent into the chamber, wherein the fourth passage, the fifth passage, and the sixth passage are fluidly isolated from each other along the additional diffusion nozzle. 
     
     
         14 . The system of  claim 11 , wherein the diffusion nozzle comprises a fourth passage configured to inject an additional fuel, an additional oxidant, or an additional diluent into the chamber, wherein the fourth passage is fluidly isolated from the first passage, the second passage, and the third passage along the diffusion nozzle. 
     
     
         15 . The system of  claim 11 , wherein the second passage is configured to inject a mixture of the oxidant and an additional diluent into the chamber. 
     
     
         16 . The system of  claim 11 , comprising at least one valve or pump, wherein the control system is configured to control the at least one valve or pump of the system such that:
 the fuel is moved through the first passage at the first flow rate based on the system being operated at the full load, and the fuel is moved through the first passage at the second flow rate based on the system being operated at the partial load, wherein the second flow rate differs from the first flow rate; or   the oxidant is moved through the second passage at the third flow rate based on the system being operated at the full load, and the oxidant is moved through the second passage at the fourth flow rate based on the system being operated at the partial load, wherein the fourth flow rate differs from the third flow rate; or   the diluent is moved through the third passage at the fifth flow rate based on the system being operated at the full load, and the diluent is moved through the third passage at the sixth flow rate based on the system being operated at the partial load, wherein the sixth flow rate differs from the fifth flow rate; or   any combination thereof.   
     
     
         17 . A system, comprising:
 a turbine combustor comprising a chamber;   a first diffusion nozzle configured to inject a first fuel flow of a first portion of fuel into the chamber of the turbine combustor, a first oxidant flow of a first portion of oxidant into the chamber of the turbine combustor, and a first diluent flow of a first portion of diluent into the chamber of the turbine combustor, wherein the first fuel flow, the first oxidant flow, and the first diluent flow are fluidly separate from one another along the first diffusion nozzle;   a second diffusion nozzle configured to inject a second fuel flow of a second portion of fuel into the chamber of the turbine combustor, a second oxidant flow of a second portion of oxidant into the chamber of the turbine combustor, and a second diluent flow of a second portion of diluent into the chamber of the turbine combustor, wherein the second fuel flow, the second oxidant flow, and the second diluent flow are fluidly separate from one another along the second diffusion nozzle; and   a control system configured to:
 change a first fuel flow rate of the first fuel flow, a first oxidant flow rate of the first oxidant flow, a first diluent flow rate of the first diluent flow, or any combination thereof to correspond to a change of a load of the system from a full load to a partial load; 
 change a second fuel flow rate of the second fuel flow, a second oxidant flow rate of the second oxidant flow, a second diluent flow rate of the second diluent flow, or any combination thereof to correspond to the change of the load of the system from the full load to the partial load; and 
 maintain a stoichiometric ratio while the load of the system corresponds to the full load and while the load of the system corresponds to the partial load, wherein the stoichiometric ratio corresponds to an equivalence ratio between 0.95 and 1.05. 
   
     
     
         18 . The system of  claim 17 , comprising:
 a turbine configured to be driven by combustion products generated from a diffusion flame produced by the turbine combustor, wherein the turbine is configured to output an exhaust gas; and   an exhaust gas compressor configured to compress the exhaust gas and route the exhaust gas from the turbine, along an exhaust recirculation path, and to the turbine combustor such that the exhaust gas forms:
 the first diluent flow of the first portion of diluent; 
 the second diluent flow of the second portion of diluent; or 
 both the first diluent flow of the first portion of diluent and the second diluent flow of the second portion of diluent. 
   
     
     
         19 . The system of  claim 17 , comprising at least one valve or pump, wherein the control system is configured to control the at least one valve or pump to:
 change the first fuel flow rate of the first fuel flow, the first oxidant flow rate of the first oxidant flow, the first diluent flow rate of the first diluent flow, or any combination thereof to correspond to the change of the load of the system from the full load to the partial load;   change the second fuel flow rate of the second fuel flow, the second oxidant flow rate of the second oxidant flow, the second diluent flow rate of the second diluent flow, or any combination thereof to correspond to the change of the load of the system from the full load to the partial load; and   maintain the stoichiometric ratio while the load of the system corresponds to the full load and while the load of the system corresponds to the partial load, wherein the stoichiometric ratio corresponds to the equivalence ratio between 0.95 and 1.05.   
     
     
         20 . The system of  claim 17 , wherein:
 the first diffusion nozzle is configured to inject a third fuel flow of a third portion of fuel into the chamber of the turbine combustor, a third oxidant flow of a third portion of oxidant into the chamber of the turbine combustor, or a third diluent flow of a third portion of diluent into the chamber of the turbine combustor; and   the second diffusion nozzle is configured to inject a fourth fuel flow of a fourth portion of fuel into the chamber of the turbine combustor, a fourth oxidant flow of a fourth portion of oxidant into the chamber of the turbine combustor, or a fourth diluent flow of a fourth portion of diluent into the turbine combustor.