Abstract: In a gas turbine the transition duct is subject to high temperature since it conducts the combustion products to the power turbine. It is normally cooled by air from the compressor. This invention improves the uniformity of cooling by forcing the cooling air to pass over all surfaces of the transition duct. Air flow passages are formed between the ducts and saddle shaped members which direct the flow of air from the compressor over the outer surfaces of the ducts.

Abstract: Method and apparatus for assembling integral platform blade groups to a rotor of a steam turbine in which the platform roots are skewed with respect to the axis of the turbine. The platform roots are formed to define a set of spaced grooves and steeples are formed on the rotor to mate with the platform roots. Grooves on the platform and in the rotor are alignable to accept a connecting member when the steeples are aligned in abutting relationship with platform roots. The connecting member joins the blade group to the rotor. In one form, the bearing surfaces of the steeples, roots and connecting member are formed to lie on one or more circles circumscribing the rotor axis.

Abstract: A gas turbine of the type having high pressure air supplied to the cavity formed by the inner shrouds of the turbine vanes is provided with film cooling of the shrouds. A manifold supplies high pressure cooling air to portions of the gaps between inner shrouds not otherwise supplied and intermittent reliefs in the strip seal between shrouds regulates the leakage of this air, over the outer surfaces of the shrouds.

Abstract: A steam turbine has an outer blade ring supporting a row of stationary blades and an adjacent downstream row of long rotatable blades. The outer blade ring has a generally conical flow-guiding surface for outwardly guiding the steam as it flows through the row of stationary blades. The outer blade ring is supported by a radially juxtaposed carrier ring having a flow-guiding surface axially adjacent to and extending outwardly from the flow-guiding surface of the outer blade ring. A spacer ring is axially adjacent to the carrier ring and has a flow-guiding surface adjacent to and extending outwardly from the flow-guiding surface of the carrier ring. An exhaust flowguide is axially adjacent the spacer ring and radially adjacent the row of rotatable blades for guiding the steam from the rotatable blades.

Abstract: Replacement low pressure end blading for a utility power steam turbine having an extended length compared to original equipment end blading providing higher efficiency. The blading incorporates extended flat areas on the blade trailing edge for improved flow characteristics and reduced losses. Mass distribution is used to tune the blade to avoid natural harmonic frequencies coincidental with turbine rotational frequencies or harmonics thereof. Blade root modifications are included to facilitate installation.

Abstract: A deaerating subsystem in a combined cycle power plant includes a deaerator and a storage tank coupled to the deaerator, the deaerating subsystem being adapted for isolation of the deaerator when it is defective even while the overall combined cycle power plant is operating. Blind flanges are provided in a downcomer and in vapor risers between the deaerator and the storage tank for such isolation. Also provided is a condensate bypass for preventing the reception of the condensate by the deaerator, and for enabling the storage tank to receive the condensate directly. Thermal energy is input into the storage tank such that controlled amounts of heated condensate from the steam generator, and controlled amounts of dry steam can be input to the storage tank while the deaerator is isolated for repairs.

Abstract: A method for modifying an original blade supporting disc (8) which is integral with a turbine rotor (2), and which has an original outline, in order to create a modified disc (8) which has an outline different from the original outline and which provides a blade-supporting region (10) of increased size, including the steps of:machining away portions (14,16) of the original disc (8) which protrude beyond the outline of the modified disc (8);building up the original disc (8) with weld metal past the outline of the modified disc (8) at all locations (14,20) where the outline of the original disc (8), after the machining step, is enclosed by the outline of the modified disc (8); andmachining away parts of the weld metal to the outline of the modified disc (8).

Abstract: A fuel nozzle assembly having a fuel nozzle tip at one end of a fuel delivery tube and a supporting flange at the other end. An air delivery tube, also secured to the support flange, encloses the fuel delivery tube to define an annular air passage therebetween. An integral fuel nozzle/end cap engages the fuel and air tubes and provides passages for fuel flowing from the fuel delivery tube and air flowing from the air delivery tube. Biasing means exerts an axial force on the air delivery tube to tighten the engagement of the tubes into an air-tight fit.

Abstract: A compressor diaphragm assembly for combustion turbines includes a plurality of vane airfoils, each of which is formed with an integral inner shroud. A segmented seal carrier is suspended from the inner shrouds, and an outer ring supports the plurality of vane airfoils from a casing portion of the turbine in a parallel relationship at a predetermined angle with respect to the longitudinal axis of the turbine. The outer ring has one or more grooves formed at the predetermined angle to engagably receive respective rows of the vane airfoils at their outer portion. Each seal carrier segment includes a pair of disc-engaging seals, and is formed to be engaged with the inner shrouds of one or more vane airfoils, in order to provide a labyrinth seal with discs assembled to form a rotating shaft.

Abstract: A gas turbine combustion chamber with an inlet and outlet has apertures in the combustion chamber wall and air scoops provided in the apertures, the air scoops having an outer tubular member and coaxially spaced inner tubular member. The spaced tubular members have inner cylindrical portions and outwardly extending flanges, with spacers disposed between and secured to the flanges with cooling air passing therebetween and through the annular air flow passage into the combustion chamber. Preferably, a radially outwardly extending arcuate section on the inner tubular member has a radius at least about one-third of the inner diameter of the inner cylindrical portion thereof.

Abstract: A method and apparatus for continually monitoring the operating state of a set of governor valves (42,60) in a steam supply system for the first stage of a high pressure turbine during operation of the turbine, the system including a source including a throttle valve (40) for supplying steam at a defined pressure to the governor valves (42,60) and a plurality of nozzles (44) each connected to deliver steam from a respective governor valve (42,60) to a respective turbine inlet region, by the steps of: monitoring (52) the pressure at the outlet of each governor valve (42,60); monitoring (50,54) the pressure at the inlet to the throttle valve(s) (40) and at the turbine first stage; and comparing (56) the monitored outlet pressure of each governor valve (42,60) with the monitored pressure at the throttle valve inlet and at the turbine first stage in order to provide an indication of the operating state of each governor valve (42,60) and to detect and alert power plant operators of valve malfunctions or inefficien

Abstract: A turbine blade shroud clearance monitoring system is comprised of a plurality of sensors for measuring the clearance between the stationary portion of the turbine and the shroud segments in each turbine blade row. The measurements are averaged by a microprocessor to produce an average clearance value for each shroud segment. The microprocessor then analyzes the average clearance values for each shroud segment to determine when the clearance between a shroud segment and the stationary portion of the turbine is approaching a critical value. Output responsive to the foregoing analysis is then generated.

Abstract: A light beam altering grid (20), having a graded slit density pattern (22), is mounted on a temperature responsive support structure (23) to traverse a light beam (28). The slit density (slit per unit length) of the grid (20) is greater at one end of the grid (20) and gradually reduces towards the opposite end of the grid (20). The grid (20) is disposed on a thermally responsive support (23) such as a bimetallic cantilever (23). The thermally responsive support (23) operates to bend by an amount dependent upon the temperature of the environment in which it operates. In this manner, the grid (20) disposed on the thermally responsive support (23) is positioned in dependence upon the environmental temperature.

Abstract: In the operation of a turbine system composed of apparatus (6,12,14,16) for generating steam and a turbine first stage (4) having inlet nozzles connected to be supplied with steam from the steam generating apparatus (6,12,14,16), the steam generating apparatus (6,12,14,16) being composed of a cascade arrangement of a boiler (6) producing steam at a selected pressure which has an assigned lower limit value, a primary superheater section (12), one or more division valves (14) presenting a steam flow passage having a controllable cross-sectional area, and a secondary superheater section (16) connected between the division valves (14) and the inlet nozzles, a method for reducing the output of the system at low load levels comprising: reducing the cross-sectional area of the steam flow passage presented by the division valves (14); and increasing the rate at which heat is supplied to the steam in the secondary superheater section (16) by an amount coordinated with the reduction imparted to the cross-sectional area

Abstract: A method for automatically calibrating a controller for a valve controlled system follows consistent procedures to make precise adjustments to valve characteristics. The controller is placed in a calibration mode, then the valve settings are modified over a full range of operation. At predetermined levels of operation, the valve settings are maintained at preset values while system performance is measured. After the full range of valve operation has been covered, adjustments are made to the correspondence between the valve settings and the levels of operation in dependence upon the differences between the measured system performance and the predetermined levels of operation. This procedure is repeated to provide average values and also to make changes to valve characteristic curves corresponding to different modes of operation such as single valve and sequential valve modes. Other control parameters may be adjusted by evaluating system performance during normal operation.

Abstract: A fuel nozzle for a gas turbine is arranged so that the air supply portion which surrounds the fuel supply portion is conveniently removable to permit cleaning but the two parts are resiliently related to permit differential expansion caused by the thermal differentials encountered during operation.

Abstract: In an axial flow turbine having a casing disposed about a rotor, a liner also disposed about the rotor and in a radially spaced relationship with the casing, such that the spaced relationship defines an annular opening, and an annular row of stationary blades positioned within the annular opening, apparatus for maintaining the efficiency of said turbine is shown to include a sealing mechanism, connected to the stationary blades, for preventing motive fluid applied to the annular opening from circumventing the stationary blades so that the efficiency of the turbine is maintained. The sealing mechanism includes a pair of sealing bars disposed between the stationary blades, the casing and the liner.

Abstract: A fuel nozzle assembly having a cylindrical nozzle tip at one end of a fuel delivery tube and a supporting flange at the other end. An air delivery tube, also secured to said support flange, encloses the fuel delivery tube to define an annular air chamber therebetween. A cylindrical face of the nozzle tip is received in an similarly sized and shaped opening in a swirl cap attached to the end of the fuel delivery tube to slideably engage the air delivery tube and the fuel delivery tube and to define a substantially constant radial spaced relationship between the cylindrical nozzle tip and the air delivery tube during variable axial expansion of the fuel delivery tube and air delivery tube. The air delivery tube is secured to the fuel delivery tube by mounting a radially expansive portion of the air delivery tube to the support flange.

Abstract: In an active shaft ground system for maintaining a rotating shaft (4) of a machine substantially at ground potential, which system includes a circuit coupled to the shaft (4) for monitoring the voltage on the shaft (4) relative to ground and a brush (6) coupled to the circuit and contacting the shaft (4) for conducting to the shaft (4) a compensating current having an amplitude and polarity adjusted for maintaining the shaft voltage substantially at ground potential, there is provided shaft condition detection circuitry (18,20,24,26,28,34,36) coupled to the circuit for monitoring the voltage on the shaft (4) relative to ground and the current flowing between the brush (6) and the shaft (4) and for producing a fault indication when the voltage on the shaft (4) relative to ground is outside of a selected range at the same time that the current flowing through the brush (6) is substantially equal to zero.

Abstract: An axial flow steam turbine has a nozzle ring circumferentially about the rotor thereof and inner and outer sections forming the ring with confronting channels therein, and a plurality of nozzle chambers communicating with the spacing between the ring sections. A plurality of nozzle blocks having radially outwardly and inwardly extending flanges are positioned in the inlet nozzle such that the same are retained therein under compressive forces exerted by the nozzle ring sections. A method for forming the same is also provided.