Abstract: A reverse flow, gas cooled dynamoelectric machine includes a rotor mounted fan at each machine end for circulating gas coolant throughout the machine. Improved pressure and efficiency for the fan is achieved by positioning stationary guide vanes upstream from the fan for directing gas coolant into the fan blades at an optimum angle. The invention is directed toward an improved guide vane assembly construction and composition.

Abstract: An automatic control system enabling comprehensive operation of a reheat steam turbine with sliding or constant pressure boilers. The control system includes an HP control valve for regulating steam flow to the high-pressure turbine according to load and speed demands, an intercept valve for regulating steam flow to the low-pressure turbine and for reheater pressure control, and a bypass flow system for bypassing excess boiler steam during periods of low loading. The bypass system includes a high-pressure bypass sub-system and a low-pressure bypass sub-system, each having a flow control valve and provision for desuperheating the steam. A signal indicative of actual load demand (ALD) and proportional to the product of boiler pressure and main control valve flow demand is produced. From the ALD signal, reference functions are generated to effect control of the bypass valves.

Abstract: The present invention provides an improvement in the art of combined steam turbine and gas turbine power plants of the type wherein the principal source of energy is a fluidized bed combustor fueled by coal. More specifically, the invention pertains to supplemental firing of the gas turbine cycle with a clean hydrocarbon fuel (CHF) at a high incremental efficiency to significantly increase overall plant efficiency.

Abstract: A method and apparatus for the selective plating of liquid gallium metal on conductive surfaces is disclosed. The preferred embodiment of the present invention comprises a cylindrical tube of nonconductive material having an open end covered with felt material. The felt retains a reservoir of liquid gallium; floating on the liquid gallium is a reservoir of water containing a soluble metal hydroxide. Extending through the water solution and the liquid gallium is an electrode which is preferably positioned in the gallium but not against the felt cover. The resulting electroplating brush is employed in a vertical or near vertical position to brush plate gallium onto an electrically conductive surface which is maintained at a negative electrical potential with respect to the electrode. By reversing polarity of the surface with respect to the electrode, deplating of the surface may be performed.

Abstract: A multichannel data acquisition system for physical measurements on rotating members of operating machinery avoids slip rings and radio telemetry for data transfer by providing a capacitive coupling link between rotating and stationary members. Electronic circuitry mounted on the rotating member provides a pulse-code modulated signal containing the measured information for transmission through the capacitive coupling link. Power required to operate the rotating circuitry is inductively coupled from a stationary high-frequency source. The rotating circuitry includes a digital counter whose count is incremented by a momentary power interruption and whose digital output corresponds to a particular measuring range, allowing a range selection to be made during machinery operation.

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 .

Abstract: A self-calibrating subcarrier telemetry system for measuring strain on rotating members of a turbine under operating conditions. A rotor mounted portion of the system includes a strain gage transducer bridge excited by a subcarrier alternating current derived from an induced power source. The transducer bridge produces an output signal, amplitude modulated by the strain signal whereby the modulation shifts the strain signal into a higher frequency portion of the spectrum away from low-frequency noise related to the rotational speed of the turbine. A calibration signal is introduced by automatically unbalancing the bridge transducer periodically at a rate related to the subcarrier frequency. The strain signal is recovered in a stationary data reception portion of the system by a synchronous detector. A reference calibration signal is provided against which receiver gain is adjusted to achieve a null, leaving only the calibrated strain signal and achieving indpendence of variations in system gain.

Abstract: An improved reheater for a moisture separator reheater includes an inlet header, an outlet header and a plurality of heat-exchange tubes connected therebetween. The inlet header is partitioned to provide at least two separate sections. Piping and control valves are also provided to supply steam to each section of the inlet header from the reheater inlet pipe. The improved reheater includes at least one bundle of tubes communicating with the header(s) via tubesheet(s). The inlet ends of the tubes may be differentially orificed whereby in combination with a nominal flow rate to the partitions, in-tube condensate subcooling is substantially eliminated with minimal scavenging steam at design conditions. At off-design, or low power level, conditions, where fixed resistances of orifices and fixed partitions cannot accommodate changes in heat transfer demand from tube to tube, the aforementioned control valves are automatically adjusted.

Abstract: An ungrounded three wire thermocouple has two thermocouple wires and a ground wire assembled in a metal cylindrical housing which can be immersed in a fluid whose temperature is to be monitored by the thermocouple. The thermocoupled housing may have an insulation surface to electrically insulate the housing from the equipment being monitored and to be isolated from the ground or potential of the equipment being monitored. The ground wire in the thermocouple assembly can be connected to the instrument grounds of the instrumentation which measures or otherwise utilizes the output of the thermocouple wires. The thermocouple is disclosed as being immersed in either a liquid or a gaseous cooling medium. A second embodiment of the invention uses two spaced three wire thermocouples mounted on an insulation support and are exposed to the flow of a gaseous medium whose temperature is to be monitored.

Abstract: An improved combined cycle gas turbine and steam turbine power plant is disclosed in which the energy source for both the steam turbine portion of the system and the gas turbine portion is a pressurized fluidized bed combustor fueled by a carbonaceous fuel such as coal. Combustion gas discharged from the pressurized combustor is processed for minimal cleanup and temperature conditioning prior to passage through a heat exchanger to heat a stream of pressurized air for driving an air-gas turbine. Following the loss of sensible heat energy through the heat exchanger, the lower temperature combustion gas is expanded through a second, combustion gas turbine so that a portion of the remaining energy is extracted at a lower temperature, avoiding problems of hot gas corrosion and fouling within the turbine. A compressor, driven by one or both gas turbines, provides both the pressurized air supply for fluidization of the bed and the stream of air to the air-gas turbine.

Abstract: Improved means for substantially eliminating condensate subcooling in single-stage moisture separator reheaters is provided by recirculating large quantities of scavenging steam through the reheater tube bundle. Heating steam for the tubeside (within the tubes of the tube bundle) of the reheater is extracted from the main steam supply upstream of the high-pressure turbine. This main steam is throttled before entering the tube bundle at part load conditions to reduce the temperature differential with respect to the high-pressure turbine exhaust steam which is to be reheated on the shellside. The tubes of the tube bundle are differentially orificed at their inlet to provide sufficient steam to each tube based on complete condensation at tube exit. At throttled, part load conditions, considerable excess scavenging steam is required to correct for the inefficiencies of the fixed orifices at these off-design conditions.

Abstract: A method of applying a duplex sheet cladding to a structural substrate is disclosed. The method utilizes hot isostatic pressure with molten glass as a pressure transmitting medium. An inner sheet cladding of aluminum is formed over the substrate and then an outer MCrAlY sheet cladding is assembled thereon which completely envelops and seals the inner cladding. Thereafter the duplex cladding is diffusion bonded to the substrate at elevated pressures and temperatures in accordance with a programmed time-temperature hot isostatic pressure cycle.

Abstract: The disclosure sets forth trip circuitry for a rotating shaft machine which includes redundant overspeed protection and means for testing the overspeed protection circuit while the machine remains in operation. Moreover, further protective circuitry is provided for detecting a failure in the speed sensing system. The overspeed protection and the speed sensing failure circuit are each connected to a relay system which may actuate a trip servo valve to a closed position.

Abstract: In a combined cycle power plant comprising a steam turbine and gas turbine connected through a heat recovery steam generator, the start-up mode for a steam turbine is based upon the shell metal temperature of the steam turbine. In some combined cycle plants, the output of the gas turbine is reduced so as to more closely match the output steam temperature of the heat recovery steam generator to the steam turbine metal temperature. This arrangement can be disadvantageous for several reasons and so it is proposed that a spray attemperator or desuperheater be incorporated between the heat recovery steam generator outlet and the steam turbine inlet. Moreover, control means are indicated for controlling the fluid input into the attemperator.

Abstract: An integral nozzle-shield assembly for a gas-cooled dynamoelectric machine such as a large turbine-driven generator is described. The nozzle-shield assembly is formed of a non-conductive, non-magnetic material such as molded fiberglass and resin and serves to channel hydrogen gas between a heat exchanger and a rotor-mounted fan used to pump the gas through coolant passages in the dynamoelectric machine, and the assembly also provides a labyrinth seal over the fan blade tips. In one embodiment, the nozzle-shield assembly includes two 180-degree halves whose thickness varies circumferentially and which may be installed in a generator by bolting their outer edges to a stator frame member of the generator and bolting the halves together at the two radial joints between halves using flat metal plate connectors.

Abstract: The field of this invention is fluid flow control through large conduits. In particular, this invention is contemplated for use in a combined cycle power plant wherein gas turbine exhaust gas is either sent through a heat recovery steam generator (HRSG) or diverted to the atmosphere. The invention is a damper and frame assembly believed to be well suited to the purpose of channeling the hot exhaust gas within the context of a combined cycle power plant either as an isolation damper to the HRSG or a bypass damper to the exhaust stack. One key consideration is the thermal relationship between the damper blade and its adjacent frame and provision is made to provide a damper blade that will not warp and a frame wherein thermal growth and distortion are limited.

Abstract: A Moisture Separator Reheater (MSR) has a plurality of tube bundles which receive high-pressure saturated (tubeside) steam therein. Steam to be reheated (shellside steam) is passed in heat-exchange relationship with the tubes of the first and second reheater tube bundles after first being dried by the panels of a moisture separator. It emerges from the shell of the reheater dried and heated. In the reheater tube bundles saturated steam at temperatures and pressures substantially higher than the shellside steam transfers heat to the shellside steam by condensation within the tubes. The steam in the second stage tube bundle is at a temperature and pressure that is substantially higher than that of the steam in the first stage tube bundle and is heating shellside steam at a higher temperature than the shellside inlet steam to the first stage tube bundle. A greater quantity of tubeside steam than is theoretically necessary is passed through the tube bundles.

Abstract: A support arrangement is disclosed for supporting an annular diaphragm in a turbine casing. The support arrangement allows the diaphragm to be vertically aligned with respect to the turbine casing and rotor and comprises in its most basic form the combination of a horizontally mounted bifurcated lug and a vertically mounted dumbbell shaped adjusting screw.

Abstract: Apparatus is disclosed for aligning brushes of a dynamoelectric machine such as a DC generator or motor to minimize arcing of the brushes. The alignment monitor processes electrical signals from brushes of a dynamoelectric machine during tests in which various levels of buck or boost current are superimposed on a preselected level of excitation current applied to the machine, and the monitor produces output signals which, together with the levels of applied buck or boost currents, are indicative of the brushholder rigging adjustment which is required to achieve the optimum rigging position for a wide range of arc-free machine operation. Included in the brush alignment monitor are filter networks for removing noise from composite signals input to the monitor, a rectifier for changing the sign of negative signal components, and networks which amplify and integrate selected high-frequency information signals to produce output signals.

Abstract: The disclosure relates to automated drain valves for pressurized fluid conduits such as steam conduits. Recognizing that there is a direct relationship between steam temperature and steam pressure at the saturation line; the saturation line is used to derive a variable set point for an automated drain system and method. The saturation temperature is compared with the actual temperature to determine the positioning of the conduit drain valves.