Systems and methods for controlling a power plant

Abstract

The present disclosure relates to systems and methods that are useful in control of one or more aspects of a power production plant. More particularly, the disclosure relates to power production plants, methods of starting power production plants, and methods of generating power with a power production plant wherein one or more control paths are utilized for automated control of at least one action. The present disclosure more particularly relates to power production plants, control systems for power production plants, and methods for startup of a power production plant.

1 . A control system for a power production plant, the control system comprising:
 a flow control logic sequence adapted for selecting the lower of a FUEL FLOW DEMAND signal for flow of a fuel to a combustor and a TURBINE INLET TEMPERATURE signal for a temperature of an inlet of a turbine, and regulating one or both of a mass and a pressure of the fuel flowing from a fuel supply system to the combustor.   
     
     
         2 .- 3 . (canceled) 
     
     
         4 . The control system for a power production plant according to  claim 1 , wherein the control system is adapted to adjust a ratio of a mass or a volume of fuel flowing through two or more different fuel lines from the fuel supply system to the combustor. 
     
     
         5 . The control system for a power production plant according to  claim 4 , wherein the control system is adapted to open/close flow control valves in each of the two or more different fuel lines. 
     
     
         6 . The control system for a power production plant according to  claim 5 , wherein the control system is adapted to open/close at least one pressure control valve in each of the two or more different fuel lines. 
     
     
         7 . The control system for a power production plant according to  claim 4 , wherein the control system is adapted to adjust a ratio of a mass or a volume of oxidant flowing through two or more different oxidant lines from an oxidant supply system to the combustor. 
     
     
         8 . The control system for a power production plant according to  claim 7 , wherein the power production plant includes at least a primary set of fuel and oxidant lines and a secondary set of fuel and oxidant lines, and wherein the control system is adapted to adjust a fuel to oxidant ratio in the primary set of fuel and oxidant lines independent of a fuel to oxidant ratio in the secondary set of fuel and oxidant lines. 
     
     
         9 . The control system for a power production plant according to  claim 7 , wherein the power production plant includes a line providing a stream of recycled CO 2 , wherein a portion of the stream of recycled CO 2  is added to one or more of the oxidant lines, and wherein the control system is adapted to adjust an oxygen concentration in one or more of the oxidant lines by adjusting an amount of the recycled CO 2  that is added to the oxidant line. 
     
     
         10 . The control system for a power production plant according to  claim 9 , wherein the oxygen concentration in each of the one or more oxidant lines is adjusted independently from the remaining oxidant lines. 
     
     
         11 . The control system for a power production plant according to  claim 9 , wherein the control system is adapted to adjust an equivalence ratio between the mass or volume of oxidant flowing through the primary oxidant line and the secondary oxidant line. 
     
     
         12 . The control system for a power production plant according to  claim 4 , wherein the control system is adapted to close a flow control valve in a primary fuel line from the fuel supply system to the combustor so that substantially no fuel flows through the primary fuel line and is adapted to open a flow control valve in a secondary fuel line from the fuel supply system to the combustor so that substantially all of the fuel flowing to the combustor is flowing through the secondary fuel line. 
     
     
         13 . The control system for a power production plant according to  claim 12 , wherein the control system is adapted to adjust an equivalence ratio between the mass or volume of fuel flowing through the primary fuel line and the secondary fuel line. 
     
     
         14 . The control system for a power production plant according to  claim 12 , wherein the control system is adapted to provide the configuration of the flow control valve in the primary fuel line and the flow control valve in the secondary fuel line during startup of the power production plant and is configured to synchronize opening of the valve in the primary fuel line with a working condition of one or both of the turbine and a compressor that compresses a stream of recycled CO 2  flowing to the combustor. 
     
     
         15 . The control system for a power production plant according to  claim 4 , wherein the control system is adapted to hold or lower the mass or volume of fuel flowing through at least one of the two or more different fuel lines from the fuel supply system to the combustor in response to an input signal indicating an operating temperature of a heat exchanger is approaching or exceeding a predefined operating maximum temperature or rate of heat increase. 
     
     
         16 . A power production plant comprising:
 a combustor;   a turbine;   a generator;   a fuel supply system;   an oxidant supply system;   a control system having a plurality of control paths for automated control of at least one act in operation of the power production plant, said control system including:
 a control path adapted to generate a control signal that is a function of a comparison of a FUEL FLOW DEMAND signal for flow of a fuel to the combustor and a TURBINE INLET TEMPERATURE signal for a temperature of an inlet of the turbine, said control path including a logic sequence adapted for selecting the lower of the FUEL FLOW DEMAND signal and the TURBINE INLET TEMPERATURE signal, and said generated control signal being effective to regulate one or both of the mass and pressure of fuel flowing from the fuel supply system to the combustor. 
   
     
     
         17 .- 18 . (canceled) 
     
     
         19 . The power production plant of  claim 16 , wherein the fuel supply system comprises at least two separately controlled fuel lines configured for passage of fuel to the combustor. 
     
     
         20 . The power production plant of  claim 19 , wherein the fuel supply system comprises at least one flow control valve and at least one pressure control valve in each of the at least two separately controlled fuel lines. 
     
     
         21 . The power production plant of  claim 19 , wherein the oxidant supply system comprises at least two separately controlled oxidant lines configured for passage of oxidant to the combustor. 
     
     
         22 . The power production plant of  claim 21 , wherein the oxidant supply system comprises at least one flow control valve in each of the at least two separately controlled oxidant lines. 
     
     
         23 . The power production plant of  claim 22 , wherein the oxidant supply system comprises an equivalence ratio control element configured to adjust an equivalence ratio between the mass or volume of oxidant flowing through the at least two separately controlled oxidant lines. 
     
     
         24 . The power production plant of  claim 23 , wherein one of the at least two separately controlled oxidant lines is a secondary oxidant flow line that comprises a flow sensor, wherein one of the at least two separately controlled fuel lines is a secondary fuel flow line that comprises a flow sensor, and wherein the control system includes a ratio control element configured to open or close the flow control valve in the secondary oxidant flow line based upon a mass or volume flow of fuel through the secondary fuel flow line. 
     
     
         25 . (canceled)