Gas turbine and steam turbine combined cycle electric power generating plant having a coordinated and hybridized control system and an improved factory based method for making and testing combined cycle and other power plants and control systems therefor
First Claim
1. A combined cycle electric power plant comprising at least a gas turbine and a steam turbine and a heat recovery steam generator connected to receive hot exhaust gas from said gas turbine and to supply steam to said steam turbine, means for generating electric power in response to mechanical drive power from said turbines, a control system for operating said plant, said control system including a gas turbine control which controls the gas turbine fuel flow and a steam turbine control which operates a steam turbine inlet valve and a bypass valve to control the turbine inlet steam, and a steam generator control which controls predetermined steam generator operating conditions all including analog electric control circuitry, means for operating said turbines and said steam genearator in response to the analog circuitry outputs, means for applying operator input signals to said controls to provide for plant startup and plant load operation, and a digital computer generating output signals for application to said controls so as automatically to provide coordinated plant startup and loading operation in satisfying a startup command and a plant load demand when said computer is selected for operation in said control system.
1 Assignment
0 Petitions
Accused Products
Abstract
A combined cycle electric power plant includes in interconnected relationship a steam turbine, two gas turbines, three electric generators, two heat recovery steam generators, a hybrid computer control system, a plant protection system and various items of auxiliary equipment. A computerized simulator is interfaced with the control system at the factory site to test the controls and the control system is then modularly disassembled in various structures and shipped to the field site for reassembly without need for extensive field testing. The control system includes a digital control computer, a digital monitor computer and modular analog controls for the turbines. Various levels of automated control can be employed including coordinated plant control which involves supervisory operation of the analog controls by the control computer. In analog control, complete plant operation is produced by operation of the analog controls without the control computer.
180 Citations
46 Claims
-
1. A combined cycle electric power plant comprising at least a gas turbine and a steam turbine and a heat recovery steam generator connected to receive hot exhaust gas from said gas turbine and to supply steam to said steam turbine, means for generating electric power in response to mechanical drive power from said turbines, a control system for operating said plant, said control system including a gas turbine control which controls the gas turbine fuel flow and a steam turbine control which operates a steam turbine inlet valve and a bypass valve to control the turbine inlet steam, and a steam generator control which controls predetermined steam generator operating conditions all including analog electric control circuitry, means for operating said turbines and said steam genearator in response to the analog circuitry outputs, means for applying operator input signals to said controls to provide for plant startup and plant load operation, and a digital computer generating output signals for application to said controls so as automatically to provide coordinated plant startup and loading operation in satisfying a startup command and a plant load demand when said computer is selected for operation in said control system.
- 2. A combined cycle electric power plant comprising at least a gas turbine and a steam turbine and a heat recovery steam generator connected to receive hot exhaust gas from said gas turbine and to supply steam to said steam turbine, an afterburner for adding heat to the gas turbine exhaust in the flow path to said steam generator, means for generating electric power in response to mechanical drive power from said turbines, a control system for operating said plant, said control system including means for controlling the fuel flow to said gas turbine, means for controlling the inlet steam flow to said steam turbine, means for controlling predetermined operating conditions of said steam generator, means for controlling fuel flow to said afterburner, means for generating a representation of a plant load demand and a plant load error, and means for automatically coordinating the operation of at least one of said gas turbine and afterburner controlling means in response to the plant load demand and the plant load error to coordinate the operation of said plant and satisfy the plant load demand representation, and means for controlling the inlet steam flow to said steam turbine in a follow mode in response to predetermined parameters other than the plant load demand and the plant load error.
- 11. An electric power plant comprising at least a steam turbine and a steam generaor interconnected to provide motive energy for driving said turbine, means for generating electric power in response to mechanical drive power from said turbine, a control system for operating said plant, means for controlling predetermined steam generator operating conditions to enable the startup of said steam generator, means for controlling predetermined steam turbine operating conditions to enable the startup of said turbine, means for controlling predetermined steam generator operating conditions to enable the load operation of said steam generator to be controlled, means for controlling the turbine inlet steam flow to enable the load operation of said turbine to be controlled, and means for automatically coordinating the operation of said steam generator and turbine controlling means so as to provide automatically coordinated plant startup and loading operation in satisfying a plant load demand.
- 20. A control system for a combined cycle electric power plant having at least a gas turbine and a steam turbine and a heat recovery steam generator connected to receive hot exhaust gas from said gas turbine and to supply steam to said steam turbine, an afterburner for adding heat to the gas turbine exhaust in the flow path to said steam generator, and means for generating electric power in response to mechanical drive power from said turbines, said control system comprising means for controlling the gas turbine fuel flow, a turbine inlet valve and a bypass valve to control the turbine inlet steam, means for controlling fuel flow to said afterburner, means for generating a representation of a plant load demand and a plant load error means for automatically coordinating the operation of at least one of said gas turbine and afterburner controlling means in response to the plant load demand and the plant load error to coordinate the operation of said plant and satisfy the plant load demand representation, and means for controlling the inlet steam flow to said steam turbine in a follow mode in response to predetermined parameters other than the plant load demand and the plant load error.
- 25. A combined cycle electric power plant comprising at least a gas turbine and a steam turbine and a heat recovery steam generator to receive hot exhaust gas from said gas turbine and to supply steam to said steam turbine, means for generating electric power in response to mechanical drive power from said turbines, a control system for operating said plant, said plant control system including a gas turbine control which controls the turbine fuel flow and a steam turbine control which operates a turbine inlet valve and a bypass valve to control the turbine inlet steam, and a steam generator control which controls predetermined steam generator operating conditions, means for operating said turbines and said steam generator in response to outputs from said turbine and steam generator controls, means for applying operator input signals to said plant control system to provide for plant startup and plant load operation, and digital computer means generating outputs for application at least to said turbine controls so as to provide at least automatic plant loading operation in satisfying a plant load demand.
- 31. A combined cycle electric power plant comprising at least a gas turbine and an electric generator driven thereby, a steam turbine and an electric generator driven thereby, a heat recovery steam generator connected to receive hot exhaust gas from said gas turbine and to supply steam to said steam turbine, means for controlling an inlet steam turbine valve to control the turbine inlet steam flow, in a follow mode in response to predetermined parameters other than the plant load demand and the plant load error, means for controlling the flow of fuel to said gas turbine in accordance wth a load setpoint, means for generating first and second representations of the loads supplied by said gas and steam turbine driven generators and an actual plant load representation from the sum of the first and second representations, a control for operating said plant including means for generating a plant load error from a plant load setpoint and the actual plant load representation, and means for varying the gas turbine load setpoint at least in response to the plant load error.
-
36. A combined cycle electric power plant comprising at least a gas turbine and an electric generator driven thereby, a steam turbine and an electric generator driven thereby, a heat recovery steam generator connected to receive hot exhaust gas from said gas turbine and to supply steam to said steam turbine, means for controlling an inlet steam turbine valve to control the turbine inlet steam flow in a follow mode in response to predetermined parameters other than the plant load demand and the plant load error, means for controlling the flow of fuel to said gas turbine, a second gas turbine and an additional electric generator driven thereby, a second heat recovery steam generator connected to receive hot exhaust gas from said second gas turbine and to supply steam to said steam turbine, means for controlling the flow of fuel to said second gas turbine, means for generating first and second representations of the loads supplied by said gas and steam turbine driven generators and an actual plant load representation from the sum of the first and second representations, a control for operating said plant including means for generating a plant load error from a plant load setpoint and the actual plant load representation, first and second afterburners for adding heat to the gas turbine exhaust in the flow paths to said steam generator, means for controlling fuel flow to each of said afterburners to add heat to the gas turbine exhaust at least after the associated gas turbine has reached its limited load operating level, means for varying a load setpoint supplied to said gas turbine or afterburner controlling means in response to the plant load error so as automatically to satisfy the plant load demand, and means for limiting the automatic load setpoint control to those turbines or afterburners selected by an operator.
- 37. A combined cycle electric power plant comprising at least a gas turbine and an electric generator driven thereby, a steam turbine and an electric generator driven thereby, a heat recovery steam generator connected to receive hot exhaust gas from said gas turbine and to supply steam to said steam turbine, means for controlling an inlet steam turbine valve to control the turbine inlet steam flow, means for controlling the flow of fuel to said gas turbine, a second gas turbine and an additional electric generator driven thereby, a second heat recovery steam generator connected to receive hot exhaust gas from said second gas turbine and to supply steam to said steam turbine, means for controlling the flow of fuel to said second gas turbine, first and second afterburners for adding heat to the gas turbine exhaust in the flow paths to said steam generator, means for controlling fuel flow to each of said afterburners to add heat to the gas turbine exhaust at least after the associated gas turbine has reached its limited load operating level and means for automatically and coordinately controlling said steam and gas turbine and afterburner controlling means to satisfy the plant load demand with only those of said controlling means selected by an operator for coordinated control being operated under coordinated control and with the others if any of said controlling means being operated under operator control.
- 39. A control system for a combined cycle electric power plant having at least a gas turbine and an electric generator driven thereby, a steam turbine and an electric generator driven thereby, a heat recovery steam generator connected to receive hot exhaust gas from said gas turbine and to supply steam to said steam turbine, said control system comprising means for controlling an inlet steam turbine valve to control the turbine inlet steam flow in a follow mode in response to predetermined parameters other than the plant load demand and the plant load error, means for controlling the flow of fuel to said gas turbine in accordance with a load setpoint, means for generating first and second representations of the loads supplied by said gas and steam turbine driven generators and an actual plant load representation from the sum of the first and second representations, a control for operating said plant including means for generating a plant load error from a plant load setpoint and the actual plant load representation, and means for varying the gas turbine load setpoint at least in response to the plant load error.
- 42. A control system for an electric power plant having at least a steam turbine and a steam generator interconnected to provide motive energy for driving said turbine, means for generating electric power in response to machanical drive power from said turbine, said control system comprising means for controlling predetermined steam generator operating conditions to enable the startup of said steam generator, means for controlling predetermined steam turbine operating conditions to enable the startup of said turbine, means for controlling predetermined steam generator operating conditions to enable the load operation of said steam generator to be controlled, means for controlling the turbine inlet steam flow to enable the load operation of said turbine to be controlled, and means for automatically coordinating the operation of said steam generator and turbine controlling means so as to provide automatically coordinated plant startup and loading operation in satisfying a plant load demand.
Specification