Abstract: An industrial production or other operational system is established by connecting apparatus which implements system operations to a digital computer system using an interface system. Machine readable definitions of events, of executable jobs, and of system variables are prepared for computer entry and ultimately for configuration of the system apparatus into an entity having operational characteristics corresponding to the entered definitions.The definitions of system variables may include definitions of signals which are coupled between the system apparatus and the computer through the interface system, and such signals may be put to system monitoring or control uses or both of these uses in the structured system. Some of the definitions may be computer programs, but most are preferably definitions of the system configuration written out in a language which a systems engineer can understand and use. Generally, definitions may include designators which are names or numbers.

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

Abstract: The inlet vanes for an induced draft (ID) fan in a power plant boiler are position controlled in accordance with the furnace pressure to limit the potential destructive power developed by the fan. The ID inlet suction temperature is sensed and a control signal is developed as a function of the inlet temperature to limit the opening of the inlet vanes during boiler startup.

Abstract: In a system and method for automatically starting, synchronizing and operating a steam turbine, control means for valve position limiting wherein such limit can be changed non-linearly. Means are provided whereby the system operator has the ability to manually select a minimum incremental change of the valve position limit as a keyboard-entered constant. If the operator enables a continuing change in the limit it is introduced arithmetically, permitting large swings in a reasonably short period of time.

Abstract: A signal representative of liquid fuel flow or gaseous fuel pressure is compared to a limit value throughout the startup and load operation of a combustion turbine. Under predetermined fuel supply conditions the turbine is either alarmed or tripped. The fuel limit value is a function of combustor shell pressure and altitude.

Abstract: A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. A gas turbine megawatt load control system is included in the control and it includes a feedforward load control which generates a fuel reference equal to the sum of a megawatt load demand and an idle speed fuel demand. The megawatt load control also includes a feedback load trimmer which provides minor corrective action on the operation of the feedforward load control. Gas turbine and combined cycle plant operation results in the generation of megawatts equal to an input demand value.

Abstract: A digital computer system provides automatic control for a steam turbine and two gas turbines in a combined cycle electric power plant during startup and load modes of operation. The gas turbine automatic control system provides speed, load and blade path temperature control functions in developing an output fuel control signal for application to each gas turbine fuel valve control. An analog control for each gas turbine selectively provides startup and temperature and load control functions as a backup for the automatic gas turbine control, and further provides gas turbine overspeed, surge and other limit controls continuously. An operator panel functions with the analog and digital controls to provide an operator interface with the plant, and an interface circuit ties the digital and analog controls together for bumpless transfer between manual and automatic modes of operation.

Abstract: 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. A plant load demand error signal is utilized for correcting a coordinated gas turbine load reference and for trimming a feedforward afterburner control signal derived from the sensed gas turbine exhaust temperatures.

Abstract: Present speed and present steam temperature are utilized in accordance with a mathematical model to evaluate present steam to turbine heat transfer and turbine heat propagation quantities, and present turbine rotor and casing surface and volume average temperatures. The model is corrected for inaccuracy based on comparison of calculated rotor to casing differential expansion with measured values, and is exercised once more with anticipated speed and steam temperature quantities to develop anticipated rotor to casing differential expansion and anticipated rotor stress. These quantities are compared with various predetermined limits to determine whether the present and anticipated speed and acceleration are within allowable limits.

Abstract: In a power plant, a solid state sequence is provided for starting an FD or ID fan, or for changing the fan speed in response to the position of the fan inlet vanes. The sequential process is self-calibrated since process events control the stepping operation of the sequencer. At the operating fan speed, boiler air flow and pressure are controlled by fan inlet vane position in accordance with plant load demand. When the fan speed is changed, a multiplier circuit causes the fan inlet vanes to reposition so as to minimize air flow changes as the fan speed changes. When one of multiple FD fans or multiple ID fans has its speed changed at a time a fan balancer control, which normally equalizes air flow, is biased to permit different fan flows through the different speed FD or ID fans.

Abstract: Power plant boiler fuel demand is transmitted as a coal feeder speed demand to a coal pulverizer control. A speed controller operates the feeder in accordance with the speed demand, and a position controller for a hot coal transport air damper positions the hot air damper to hold the mill outlet temperature to a setpoint value and to increase or decrease damper position in accordance with a feedforward signal representing the feeding speed demand. A position controller for a cold air damper regulates the total primary air flow to a value needed for safe and smooth transport of the pulverized coal to the boiler burners, and it accordingly acts as a process trim on the feedforward control applied by the hot damper controller.

Abstract: 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. Loading and unloading of the steam turbine is accomplished automatically in coordinated plant control as a function of steam throttle pressure.

Abstract: A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. In the automatic and manual modes of operation, the control system develops a fuel reference signal for the throttle valve position control by means of a speed/load control which functions on a feedforward speed control basis without speed feedback correction. An electrical overspeed protection control is directly coupled to the throttle valve position control to limit turbine speed to a first reference value when the breaker is closed and to limit turbine speed to a lower reference value when the breaker is open. Electrical and mechanical overspeed protection systems directly trip the turbine at higher speed references.

Abstract: A combined cycle power plant includes a gas turbine and an afterburner to which fuel is supplied for speed and load control. Water is injected into the turbine combustors by a controlled water injection system to control total NOx emissions from the turbine and the afterburner as a function of turbine load corrected for changes in inlet air temperature and inlet guide vane position.

Abstract: A gas turbine and an afterburner are operated with a dual liquid fuel system. During protective stops, logic controls are provided for initiating a transfer from operating fuel to a flushing fuel after predetermined conditions are satisfied. After fuel transfer, shutdown is completed without setting trips and restart can be achieved without special prestart preparation of the fuel system.

Abstract: A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. In the control system, an automatic digital computer control generates position setpoints for the gas turbine fuel valves and the steam turbine inlet valves to control speed and load. A synchronizer system includes a sequencer which is largely embodied in the digital computer as an element of the automatic control and it further includes a synchronizer which is external to the automatic control. The sequencer connects the synchronizer to synchronize the three generators in a sequence which depends on the startup and loading operation of the turbines, the synchronization operation of the synchronizer and the operation of the breakers. Turbine speed changes are initiated by the speed/load control under synchronizer control.

Abstract: The majority of a number of relays is held in a quiescent state, without power, in a local maintenance controller preparatory to assumption of control of a gas turbine power plant. Control transfer may be manually requested or may occur automatically in response to failure of the plant's primary control system. Regardless of the cause of transfer, a time delay relay is utilized to allow the quiescent relays sufficient latching time. The time delay period is chosen to reflect the maximum period of time for which a lack of trip availability can be safely tolerated.The relay sequencing arrangement is adapted so that when the quiescent relays are energized, alarm circuitry for predetermined plant parameters is automatically reset for on-line transfers, thereby allowing more rapid and efficient transfer and minimizing the need for operator intervention. Alternative means for manually resetting the alarm circuitry is also provided.

Abstract: A black start generating system for a steam plant comprises a gas turbine-generator and a control system which operates the turbine in a modified dead load mode to accept successive load steps in accordance with a black plant startup sequence. In the dead load mode, certain limits are placed on control operations to protect the turbine while permitting load stepping during plant startup.

Abstract: A gas turbine set, a heat recovery boiler and a steam turbine are operated in a combined cycle to generate electric power. A gasifier generates fuel gas for the gas turbine from a reaction of fuel and compressed air supplied from the gas turbine. The booster compression process is regenerative, i.e. the air is cooled by the booster outlet air before entry to the booster and the booster outlet air is reheated by the booster inlet air prior to passage to the gasifier. Generated fuel gas is controllably heated by a heater using hot water from the heat recovery boiler. Gasifier process control is provided by a fuel ratio controller which varies the gasifier inlet fuel flow as gasifier inlet air flow varies with plant load changes.

Abstract: Modular operating centers for use in electric power generating plants and other industrial and commercial plants, processes and systems are constructed by using a novel prefabricated modular technique. This technique includes loading a plurality of transportable room-size building modules with control system equipment at a factory site. Typically, the control system equipment includes sophisticated and complex electrical and electronics data processing and control equipment. The control system equipment is installed and bolted down in the different building modules and the equipment in each module is inter-wired at the factory site. Temporary inter-module connections are established between the control system equipment in different ones of the building modules and such equipment, as a whole, is then thoroughly tested and adjusted under simulated use conditions. Thereafter, the loaded and tested building modules are separated and separately transported to the industrial or commercial installation site.