Abstract: An electric power plant, including a fossil fired boiler and a steam turbine, is operated by a control system including a plant unit master. The control system includes a boiler control for determining the inputs of fuel, air and water, and a turbine control for determining the position of the throttle valves introducing steam from the boiler to the turbine. The plant unit master provides a load demand reference in parallel to the boiler control and to the turbine control, whereby the turbine and the boiler are operated in a coordinated manner. Measuring means provide indications of throttle pressure, power generated by the system and turbine rotor speed. Distinct controllers, each including a controller and responsive to one of the aforementioned indications and its corresponding reference, modify the load demand reference before it is applied to the turbine control or to the boiler control.

Abstract: A quick-acting stud tensioner tool for enabling the loosening or tightening of a stud nut on a reactor vessel stud. The tool engages the vessel stud by closing a gripper mechanism around an upper end of the vessel stud upon a transfer of the mass of the tool from a hoist to a support structure surrounding the vessel stud. After the stud has been elongated, the gripper mechanism releases the vessel stud when the mass of the tool is transferred from the support structure surrounding the vessel stud to the hoist.

Abstract: A steam turbine is provided with an electrohydraulic control system having an automatic control which includes a digital computer and further having a manual backup control for operating the turbine on automatic or operator switchover to backup control. The automatic control includes control elements and logic elements associated with valve control loops coupled to the turbine and high and low limits and other constants, setpoints and other parameters are characteristic to these control and logic elements and the interrelations among them and the turbine. A switch arrangement is provided for generating parameter value signals corresponding to changed values for the system parameters and for coupling the parameter value signals to the automatic control system where they are registered. The automatic control system is structured to reject invalid parameter value changes and to register only those parameter value changes which can be validly entered as part of the system structure.

Abstract: A modularly constructable support arrangement is provided for pressurizer safety and relief valves in a nuclear power plant. A common header is supported by four sets of columnar legs which are secured to pressurizer vessel side wall lugs. The safety and relief valves are securely disposed and connected through short pipe runs to discharge steam into the header.

Abstract: The invention comprises a cooled turbine rotor blade having an improved blade tip structure. A recessed tip is provided at the leading edge end of the blade tip on downstream turbine blades which are too narrow to support a blade tip cavity over the entire exterior surface of the blade tip without interfering with cooling airflow from apertures in the exterior surface. The recessed tip structure protects apertures therein from blockage by a blade tip smear and does not substantially reduce the performance efficiency of the blade.

Abstract: A catalytic combustion system includes a combustor having a diffuser end portion supported for sliding thermal growth by a catalytic unit through a spring clip ring assembly. The catalytic unit includes two shell portions which are secured together to support a catalytic element within the shell. A ring supports the catalytic unit on the transition duct for sliding thermal axial growth through a spring ring and receives catalytic element thrust. The parts are structurally arranged for installation and maintenance through an opening in the turbine casing.

Abstract: An industrial production or other operational system is established by connecting apparatus which implements system operation 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 rotating brushless exciter generator coupled to a power system through a breaker. One or more of the turbine-generator plants are operated by a hybrid digital computer control system during sequenced startup, synchronizing, load, and shutdown operations. The program system for the computer and external analog circuitry operate in a multiple gas turbine control loop arrangement. Logic macro instructions are employed in programming the computer for logic operations of the control system.

Abstract: A multiprocessor computer control system for a process includes at least two central processors and respectively associated input/output systems. Control system faults are detected and a bootstrap microprocessor is triggered into its fault detector and recovery mode. The output control signals are placed on and central processors are stopped and restarted and then it is determined which if any of them is to be inoperative. A reconfigured control system is defined with the inoperative unit(s) excluded. The microprocessor switches the input/output systems as necessary to structure the control system in reconfigured form so that process control can resume without disturbance.

Abstract: A transpiration cooled ceramic blade for a gas turbine is shown wherein a spar or strut member defining a root portion and an airfoil portion provides the main structural component of the blade. The air foil portion contains longitudinal grooves in the surface in flow communication with an air flow passage in the root portion and a flexible perforated ceramic tape is wrapped around the air foil portion with the perforations therein in registry with the grooves in the core. The flexible ceramic tape and the strut assembly are heated initially to a low temperature to drive off the binder forming the tape and then heated to a relatively high temperature to fuse the ceramic component of the tape together and to the strut to form a unitary blade structure with internal air flow paths and transpiration cooling orifices through the skin.

Abstract: A motor control system includes a motor system having a pole-amplitude-modulated (PAM) motor, a motor breaker, and a speed switch coupled between the motor breaker and the PAM motor. The PAM motor is coupled to a fan in an exhaust duct having a controlled damper for controlling air flow therethrough. A control system step logic sequencer includes means responsive to permissive signals for providing in sequence control signals to the motor breaker and speed switch in response to confirmation signals received from the motor breaker, the speed switch and the PAM motor.

Abstract: A combustion turbine vane assembly is shown having a retainer block mounting each individual cooled turbine vane. The retainer block has a pair of axially extending opposed rails for sliding receipt of complementary engaging opposed rails on the outer surface of the vane shroud. The block defines a cooling air aperture therethrough. The inner surface of the block is supported a predetermined distance from the opposed surface of the vane shroud defining a cooling fluid receiving chamber therein. The separated distance permits controlled cooling air leakage into a space between the block and the outer shroud. The radial walls of adjacent outer shrouds have complementary axial grooves machined therein and a seal member is disposed therein to bridge the gap and minimize loss of the cooling air.

Abstract: In a combined cycle power plant having one or more combustion turbines and a steam turbine, a dry catalytic NOx removal module is disposed in each of the turbine exhaust stacks. A waste heat exchanger system includes an economizer coil and a pair of high pressure evaporator coils on upstream and downstream sides of the NOx removal module to generate steam for injection into the turbine combustors and for delivery to a superheater coil upstream from the upstream evaporator coil. A bypass stack across the upstream evaporator coil is damper controlled to regulate the exhaust gas temperature at the entry to the NOx removal module. A downstream low pressure evaporator coil generates steam for induction into the low pressure section of the steam turbine. Superheated steam is supplied to the high pressure section of the steam turbine.

Abstract: In a single cycle combustion turbine power plant, a dry catalytic NOx removal module is disposed in the turbine exhaust stack. A waste heat exchanger system includes an economizer coil and a pair of evaporator coils on upstream and downstream sides of the NO.sub.x removal module to generate steam for injection into the turbine combustors. Bypass stacks across the coils are damper controlled to regulate the exhaust gas temperature at the entry to the NOx removal module. The compressor inlet guide vanes are closed to increase exhaust gas temperature as required after the upstream evaporator bypass flow reaches zero and no longer controls gas temperature. If the inlet guide vanes reach the fully closed position, reductant injection flow is shut off to terminate the NOx removal process under low exhaust gas temperature conditions. A plant afterburner is operated to add heat to the exhaust gas if gas temperature is too low.

Abstract: Two gas turbine power plants are started and accelerated by fuel controls on selection of dead load mode. The startup is coordinated so that one turbine-generator is controlled as the lead unit and it is driven to a speed higher than normal, short of overspeed condition at which time its breaker is closed on an auxiliary bus. Shortly thereafter the second turbine-generator is synchronized to the first and its generator breaker is closed to the auxiliary bus. The two units are then ready for a simultaneous 200% load pickup from the dead load bus. After the load is applied, the lead unit is placed under isochronous control and the follow unit is tracked to the lead unit. Turbine lead/follow roles can be reversed during startup under certain conditions, and predetermined data is exchanged between the controls to enable coordinated dead load pickup operation.

Abstract: A paired stage flash evaporator unit is provided with an elongated shell having respective higher temperature and lower temperature evaporation chambers extending along a bottom portion of the shell space and separated from each other by an interstage elongated partition wall. A condenser tube bundle extends longitudinally between opposite shell end walls in an upper portion of the shell space. A transverse interstage partition separates the tube bundle into separate condenser chambers. Each condenser chamber is paired with an evaporation chamber by means of shroud and other isolation structure thereby forming two paired stages in the unit.In each stage, a liquid separator mesh extends coextensively with the evaporation chamber and both condenser chambers to direct vapor from the evaporation chamber into a flow path above the mesh.

Abstract: A following error monitoring system for detecting axis positioning failure modes in a numerical control system and causing a cessation of movement as a result of the detecting of such failure mode. The system comprises an integration means and a time delayed negative feedback of the output of the integration means provides a "predicted following error" signal which is used to provide a comparison to a "error threshold signal" for determining unacceptable axis positioning deviation.

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. The afterburner fuel flow is controlled through a feedforward setpoint signal derived as a predetermined function of sensed gas turbine exhaust temperature.

Abstract: A paired stage flash evaporator unit is provided with an elongated shell having respective higher temperature and lower temperature evaporation chambers extending along a bottom portion of the shell space and separated from each other by an interstage elongated partition wall. A condenser tube bundle extends longitudinally between opposite shell end walls in an upper portion of the shell space. A transverse interstage partition separates the tube bundle into separate condenser chambers. Each condenser chamber is paired with an evaporation chamber by means of shroud and other isolation structure thereby forming two paired stages in the unit.In each stage, a liquid separator mesh extends coextensively with the evaporation chamber and both condenser chambers to direct vapor from the evaporation chamber into a flow path above the mesh. A distillate collection tray is supported beneath the tube bundle and it is divided into stage-separated tray portions by the transverse interstage partition.

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.