Abstract: Rotor turning gears for turbines selectively engage with and disengage from rotor ring gears to provide for rotation of the turbine rotor when it would otherwise cease rotation. This is to equalize the effect of thermal stresses on the rotor as it cools down from operating temperatures. The turning gear is positioned by a movable carriage and interlock. The interlock prevents inadvertent engagement of the turning gear and rotor; inadvertent steam admission to the turbine when the turning gear is engaged and assures gear mesh oil to the turning gear during turning gear engagement.

Abstract: In a non-contact heat exchanger such as a heat recovery steam generator, the performance efficiency is dependent upon full utilization of the available hot gas flow. In a heat recovery steam generator, hot gas is channeled past fluid carrying tubes whereby the tube-side fluid (water) is heated into steam. It has been discovered that gas flow along the heat exchanger sidewalls results in an unacceptable heat loss and that this loss may be corrected by the use of sidewall baffles so constructed as to obviate any alignment difficulty.

Abstract: The invention is practiced by providing a plurality of turbine-driven systems each producing an output proportional to a respective control signal, means for generating a respective first output signal for each of the turbine-driven systems proportional to a respective first system-output indicating parameter, means for generating a respective error signal for each of the turbine-driven systems proportional to any deviation of a respective second system-output indicating parameter from a respective complementary portion of the combined second system-output parameters of the systems, and means for generating the respective control signal of each of said turbine-driven systems and proportional to any deviations of respective ones of the first output signal and the error signal from a respective predetermined reference value of said first parameter, whereby a predetermined relationship of the individual outputs of the turbine-driven systems is maintained.

Abstract: A coupling between a prime mover and a dynamoelectric machine should include electrical insulation between the connected shafts so as to preclude the transmission of eddy currents between the dynamoelectric machine to the prime mover shaft. This insulation may be provided at the radial interface between coupling members. However, it has been found that the torque carrying capability of a coupling may be enhanced by providing a circumferential electrical insulation between radially inner and outer hubs which comprise the coupling member on the dynamoelectric machine side of the coupling.

Abstract: This application is directed to a method and apparatus for improving the useful thermal yield of a saturated water flashed steam source over a wide range of steam turbine load. A flash tank pressure control in its simplest form maintains constant steam pressure with variable input water flow and inlet water enthalpy. This permits optimizing a design point relationship between water temperature, water flow, flash tank steam pressure and turbine stage pressure. If turbine stage pressure is used as a reference to reduce the flash tank steam pressure for part load operation, then more steam is available from a given flow of saturated water, and the throttling loss through the pressure control valve can be minimized.

Abstract: A power plant may include a steam generator and a steam turbine wherein the steam generator provides steam to the turbine for driving the turbine and exhausted steam from the turbine is condensed in the turbine condenser to be pumped back to the steam generator as feedwater. In order to maintain minimum feedwater pump flows and to provide an alternative flow path should the steam generator require less than the available feedwater flow, a recirculation loop is provided for returning a portion of the feedwater to the turbine condenser. According to the present invention, this return flow to the condenser may be used for deaeration of condensate and for the attemperation of bypass steam.

Abstract: A communication system is disclosed for a distributed control arrangement comprising a plurality of communication nodes, each corresponding to a separate physically remote operating unit of a common installation. Each node includes a set of port buffers respectively associated with separate subsystems of the corresponding operating unit, a common node bus and a controller. Each port buffer is adapted to establish a 2-stage transfer link between its corresponding subsystem and the controller, in which the port buffer provides intermediate data storage. One port buffer of each node is coupled to a secondary station associated with that node which is slaved to a primary station. The primary station issues commands through a common data link to the secondary stations and communicates with selected subsystems associated with each node through the secondary station corresponding to that node.

Abstract: In a dynamoelectric machine having a rotating field and a stationary stator core, electrical conductors are contained within axially-extending radial slots which are part of the stator core construction. The electrical conductors for stator bars are subject to electromagnetic forces and thermal cycling effects which, over a period of time, tend to cause the stator bars to become loose within their slots. The invention is an improved wedging system which provides both an immediate and residual force on the stator bars which holds the bars in place even after certain settlements have taken place. Further, it is possible to determine the amount of force applied initially to the stator bars by the wedging system and any residual force after a period of operation.

Abstract: This disclosure is directed toward combined cycle power plants which include at least one gas turbine and one steam turbine thermally coupled through a heat recovery steam generator (HRSG). Exhaust gas from the gas turbine is used to heat feedwater into steam for the steam turbine. One optimum criterion is to design the HRSG so that the exit temperature of the exhaust gas is at a minimum without the occurrence of sulfur condensation on the economizer tube bundles. The allowable minimum temperature varies with the sulfur content of the fuel and, hence, it would be desirable to be able to adjust the tube surface temperature as necessary in accordance with the sulfur content of the gas turbine fuel.

Abstract: In a power plant, a deaerator is a feedwater conditioning device which provides direct contact feedwater heating as well as providing for oxygen removal to inhibit corrosion. Under some conditions, called transients, rapid depressurization could occur in the deaerator which might result in damage to internal deaerator parts. By limiting the condensate flow into the deaerator, the rate of depressurization can be reduced. A control system is described which will react to a reduction in turbine load by reducing the flow of condensate to the deaerator.

Abstract: In a power plant which includes a steam turbine with main control valves for admitting steam into the steam turbine and a steam bypass with bypass control valves for diverting steam around the steam turbine directly into a condenser, it is necessary to coordinate the operation of the respective valves so that the steam turbine can be started, brought up to speed, synchronized with a generator and then loaded as smoothly and efficiently as possible. The present invention provides for such operation and, in addition, allows for the transfer of power plant operation from the so-called turbine following mode to the boiler following mode through the use of the sliding pressure concept. The invention described is particularly applicable to combined cycle power plants.

Abstract: The rotating field of a dynamoelectric machine comprises a rotor having electrically conductive windings extending along the axial length of the rotor. The windings are disposed in axially extending slots and the slots include electrical insulation for preventing the transfer of electric current between the windings and the rotor body. A direct cooled generator field is one which is cooled by the atmosphere surrounding the field; e.g., hydrogen or air, and is designed so that the gas coolant is pumped radially through the windings and axially through sub-slots in the rotor body. The present invention is concerned with sub-slot covers which are designed to improve the electrical insulating properties of the cover by increasing the electrical path length between the windings and the rotor body and by obviating the formation of electrical paths due to the possible accumulation of foreign material.

Abstract: Non-contact heat exchangers comprise a gas carrying duct which has fluid carrying tubes inserted therein so that hot gas may heat the tube fluid. This simple principle is extrapolated into a heat recovery steam generator for a combined cycle power plant where hot gas turbine exhaust gases are used to heat steam turbine feed water in order to produce steam. A noise/vibration problem may be generated at certain gas turbine loads which create stimulus frequencies at or near boiler tube response frequencies. The invention proposes an optimum arrangement of upstream baffles which suppress the stimulus frequency generated by the gas flowing through the duct.

Abstract: Some power plants may produce both power and process steam as output products and may be referred to as cogeneration power plants. This type of power plant may include at least one extraction type steam turbine in order to conveniently output process steam. Sometimes the available power plant steam supply is insufficient to satisfy both load demand and process steam requirements whereupon it may be desirable to prefer load demand over process steam requirements. The present invention is a control system for electronically implementing that preference.

Abstract: In a hot gas duct wherein it is desirable to retain heat within the duct by insulated sidewalls and wherein the duct is substantially longer than it is wide, it is necessary to support the duct against excessive deformation in the lateral direction. Exterior support structures are unacceptable because locating cross members or struts becomes problematic. Interior support structures must be carefully designed so as not to inhibit thermal expansion and contraction within the duct. It is proposed that a lateral bracing system or truss be disposed entirely inside the hot gas path and provision be made to ensure adequate facility for uniform expansion of the truss within the hot gas duct.

Abstract: In large turbine machines, it is critical to bearing performance that the turbine rotor remain aligned with the bearing surfaces. Misalignment can occur due to high thrust loads or thermal deformation. The object of the invention is to ensure correct rotor-bearing alignment under all operating conditions. The invention is a self-aligning bearing support structure capable of accommodating angular rotor misalignments. The bearing support structure includes a bearing casing which transfers axial loads or thrusts to the bearing standard through a yoke attached to the bearing casing and to the bearing standard by pairs of axially oriented flex struts. In combination with the axially oriented flex struts a transverse flex plate supports the bearing vertical load.

Abstract: A prime mover which is equipped with an electric speed governor may produce adequate electrical power output through a shaft driven permanent magnet alternator to run the electric speed governor. However, initially an auxiliary power source must be connected to the electric governor until the permanent magnet alternator becomes self-sustaining. The present invention is an electrical circuit which will automatically provide start-up power from an auxiliary source and then switch to the permanent magnet alternator. Certain safety interlocks are provided in case of speed pick-up failure.

Abstract: In a counterflow non-contact heat exchanger, tube bundles carry fluid back and forth across a hot gas path. As the fluid in the tubes flows vertically downward the temperature of the fluid rises. As the gas rises in the heat exchanger it loses heat due to the heat exchange process. This means that the temperature profile of a tube bundle will show a greater thermal expansion in the lower tubes. The present invention seeks to provide an efficient and improved support arrangement for heat exchanger tubes to accommodate this phenomenon by supplying a pivotally mounted tube support plate which will rotate and translate slightly from a substantially vertical plane to accommodate thermal expansion. Further, if there are multiple tube bundles, additional tube support plate sections will allow a tube support plate to articulate in sections to accommodate thermal movement.

Abstract: This disclosure relates to apparatus for steam generation or boilers and more specifically, discloses a system for controlling the fluid level in a boiler drum. Drum level control requires an observation of the fluid level in the drum and also takes into account steam flow out of the drum and feedwater flow into the drum. The present invention improves upon the prior art by providing an unusually responsive drum level controller in combination with inputs relating to steam flow and water flow. This is accomplished by considering the derivative of steam flow minus water flow in combination with a fast drum level controller.

Abstract: In the field of closed loop control systems, a reference signal input is compared with a feedback signal to provide an error signal which then initiates corrective action until the feedback signal duplicates the reference signal. Hence, the reference signal may be appreciated as the set point at which the control system should operate. The disclosure relates to a manual input reference signal circuit which may be used to input a desired reference speed signal into a control system circuit for a prime mover. Provision is made for both local and remote manual signal input and priority logic is included for selecting the most appropriate reference signal. Inhibit logic dictates the floor and ceiling for the range of prime mover operation .