A control method for optimizing an operation of a power plant having generating units during a selected operating period subdivided so to include regular intervals within which each of the generating units comprises one of an on-condition and an off-condition. The control method may include: determining a preferred case for each of the competing operating modes for the intervals; based upon the preferred cases, selecting proposed turndown operating sequences for the selected operating period; determining a shutdown operation for each of the generating units comprising the off-condition for one or more intervals during the selected operating period and, therefrom, calculating a shutdown economic outcome; determining a turndown operation for each of the generating units comprising the on-condition for one or more intervals during the selected operating period and, therefrom, calculating a turndown economic outcome; calculating a sequence economic outcome for each of the proposed turndown operating sequences; and comparing the sequence economic outcomes.

Methods and systems for enhancing control of power plant generating units

A combined cycle coal gasification power plant includes a coal gasifier which generates low BTU coal gas for consumption by a gas turbine. Before being applied to the gas turbine, the coal gas is passed through a clean-up system which removes undesirable constituents from the coal gas. Efficient operation of the clean-up system requires that a predetermined discharge pressure of clean coal gas leaving the clean-up system must be maintained. A control system controls the coal gasifier according to either one of the discharge pressure of clean coal gas and the turbine power output requirement while maintaining the clean coal gas discharge pressure and power output at predetermined values.

Coal gasification power generation plant

A process for increasing the specific output of a combined cycle power plant and providing flexibility in the power plant rating, both without a commensurate increase in the plant heat rate, is disclosed The present invention demonstrates that the process of upgrading thermal efficiencies of combined cycles can often be accomplished through the strategic use of additional fuel and/or heat input In particular, gas turbines that exhaust into HRSGs, can be supplementally fired to obtain much higher steam turbine outputs and greater overall plant ratings, but without a penalty on efficiency This method by and large defines a high efficiency combined cycle power plant that is predominantly a Rankine (bottoming) cycle Exemplary embodiments of the present invention include a load driven by a topping cycle engine, powered by a topping cycle fluid which exhausts into a heat recovery device

High density combined cycle power plant process

An oven according to some embodiments includes an oven chamber in which food is cooked, a heating element, a fan, a sensor for sensing the temperature of the oven chamber, a remote input device, and a controller configured to receive a signal from the remote input device and to change the fan or heating element based at least in part upon the signal received from the remote input device. In a method of operating the oven according to some embodiments, the oven enters an operating mode from an energy-savings mode responsive to receiving an signal from a remote device.

Conveyor oven apparatus and method

A method and system of controlling a gas turbine engine is disclosed. The engine has sensors to detect one or more parameters and actuators adapted to respond to commands. The method includes receiving data from the sensors of the engine for one or more measured or sensed parameters, estimating a state of the engine by estimating one or more unmeasured or unsensed parameters using the data from the sensors and a predictive model of the engine, generating commands for the actuators based on the state using an optimization algorithm; and transmitting the commands to the engine. The system includes a state estimator adapted to estimate a state of the engine by estimating one or more unmeasured or unsensed parameters using data from the sensors of the engine for one or more measured or sensed parameters. The estimator includes a model of the engine. The system also includes a control module adapted to generate commands for the actuators based on the state. The control module includes an optimization algorithm for determining the commands.

Model-based control systems and methods for gas turbine engines

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.

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

Steam flow and pressure conditions needed in a turbine to satisfy the speed and load demand of an electric power generating system are controlled by a programmed digital computer system during start-up, synchronization and load operation Manual backup control is provided for the computer control Throttle valve tests are provided under digital control and transfers are made to manual backup control if predetermined task errors occur

System and method for starting, synchronizing and operating a steam turbine with digital computer control

A combined cycle electric power plant includes two gas turbines, a steam turbine, and a digital control system with an operator analog or manual backup. Each of the gas turbines has an exhaust heat recovery steam generator connected to a common header from which the steam is supplied by one or both of the steam generators for operating the steam turbine. The control system is of the sliding pressure type and maintains a predetermined steam pressure as a function of steam flow according to a predetermined characterization depending on the number of steam generators in service to limit the maximum steam velocity through the steam generators, and reduce the probability of water carryover into the steam turbine. Such control is always maintained by the bypass valve. The turbine control valve responds to the speed/load demand only, except when the bypass valve is closed and the rate of steam generation is insufficient to maintain a predetermined pressure flow relationship.

Combined cycle electric power plant with a steam turbine having a sliding pressure main bypass and control valve system

A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. Afterburners further heat the exhaust gases from each gas turbine prior to their passage to respective heat recovery sections of the steam generator. The power plant control system provides coordinated plant control or coordinated control of selected turbines and afterburners in both startup and load operations, with load distribution optimized according to the turbines under coordinated control. Transfer between coordinated control and alternate modes of plant control may be done by operator selection or automatically upon sensed conditions.

Multiple turbine electric power plant having a coordinated control system with improved flexibility

A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes a superheater tube through which a fluid, e.g. water, is directed to be additionally heated into superheated steam by the exhaust gas turbine gases. An afterburner further heats the exhaust gas turbine gases passed to the superheater tube. The temperature of the gas turbine exhaust gases is sensed for varying the fuel flow to the afterburner by a fuel valve, whereby the temperatures of the gas turbine exhaust gases and therefore of the superheated steam, are controlled. The afterburner fuel flow is controlled through a feedforward setpoint signal derived as a predetermined function of sensed gas turbine exhaust temperature.

Robert Uram

Papers

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

System and method for starting, synchronizing and operating a steam turbine with digital computer control

Combined cycle electric power plant with a steam turbine having a sliding pressure main bypass and control valve system

Multiple turbine electric power plant having a coordinated control system with improved flexibility

Combined cycle electric power plant with feedforward afterburner temperature setpoint control