Showing papers on "Turbine published in 1972"

Porous abradable turbine shroud

Abstract: A turbine blade tip-sealing shroud between a rotating bladed turbine and the surrounding casing of a turbojet engine is formed of substantially cylindrical inner and outer layers of porous sintered metal or similar material. The porosity of the radially inner layer is greater than the porosity of the outer layer and is adapted to withstand frictional rubbing contact with the turbine. The outer layer of the shroud is impinged by cooling air for transpiration cooling of the shroud, the amount of cooling air passed therethrough being metered by the porosity of the outer layer. The relative porosities of the two layers enable the shroud to meter the flow of cooling air to maintain this flow in spite of abrasion of the inner layer and the constriction of the pores thereof by the rotating bladed turbine.

Start-up converter

Abstract: Apparatus for starting up the turbine of a gas turbine unit or a pump storage unit having a generator coupled to the turbine, which includes a frequency converter of variable output frequency which connects a supply voltage to the generator during start-up. The generator is accelerated by the frequency converter as a synchronous motor until a predetermined speed is reached. The frequency converter is a static semiconductor converter. The starting-up apparatus eliminates the need for providing a separate starter motor for the turbines. According to a further embodiment, the semiconductor converter includes a speed control arrangement for maintaining the generator shaft at an adjustable, desired speed until the turbine unit is either accelerated by the frequency converter to the predetermined speed or is further decelerated or stopped. The speed control arrangement avoids the very rapid accelerations and decelerations of the turbine shaft otherwise accompanying start-up and shut down, thereby preventing distortions in the turbine shaft caused by non-uniform heating and cooling.

Turbine driven electrical generator

Abstract: A turbine driven electrical driven generator set having one or more turbines positioned above the generator to provide a power source at locations where there is a minimum available floor space. An acoustical enclosure enclosing the turbine and generator and having air filters for filtering the generator cooling air and the intake air to the turbine. An air fan driven from the generator for cooling the generator and the oil in the turbine and the reduction gearing between the turbine and the generator through an air/oil heat exchanger. The air fan cooling the turbine after shutdown.

System and method for monitoring and controlling operation of industrial gas turbine apparatus and gas turbine electric power plants preferably with a digital computer control system

Abstract: A hybrid digital computer gas turbine power plant control system which may operate in a multiple control loop arrangement is provided with selected process variable monitoring and control and turbine system failure detection means. More specifically, open, shorted, grounded and reversed thermocouples are detected and alarmed. Problems of any one combustor in a multiple combustor arrangement are similarly detected and alarmed. Additionally, automatic correction of previously computed temperature related control inputs is provided in response to detected variations from a predetermined temperature reasonability criterion. Novel placement and orientation of system thermocouples facilitates achieving improved monitoring, detection and control.

System and method for operating industrial gas turbine apparatus and gas turbine electric power plants preferably with a digital computer control system

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.

System and method employing a digital computer with improved programmed operation for automatically synchronizing a gas turbine or other electric power plant generator with a power system

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. Automatic synchronization is achieved with a hybrid subsystem which includes the programmed computer and external phase detection circuitry. An automatic synchronization program for the computer is divided into rough speed and voltage matching, fine speed matching and breaker closure subprograms.

Modular gas turbine engine

Abstract: A modular gas turbine engine for an aircraft includes a cold module, a combustion liner assembly, a nozzle diaphragm assembly, and a gas generator turbine module, all of which may be readily removed and replaced in the field without the use of special tools. The invention herein described was made in the course of, or under a contract or subcontract thereunder (or grant), with the Department of the Army.

Improvements in or relating to turbine blading

Abstract: 1287223 Turbine rotor blading ASSOCIATED ELECTRICAL INDUSTRIES Ltd 19 Jan 1971 [2 Feb 1970] 4866/70 Heading FIT The blades 2 of a turbine rotor are mounted in groups 1 of two or more blades, each group having a common root 3 and a common shroud portion 4, movement restraining means interconnecting the shroud portions of adjacent groups. In the arrangement shown the restraining means is a metal strip 5 riveted to shroud portions 4. In a modification, Fig. 2 (not shown) the restraining means is a strip (6) fitting in a dovetail slot (7) in the radially outward surfaces of shroud portions 4 with freedom for circumferential movement. In a further arrangement, Fig. 3 (not shown) lacing wires (8) passing through grooves (9) in opposite sides of the shroud portions are used. In all the arrangements each common root 3 or shroud portion 4 may be formed from a single piece of material or from separate pieces rigidly secured together, e.g. by welding.

Gas turbine with removable self contained power turbine module

Abstract: An aircraft gas turbine engine includes a power turbine module having a self-contained turbine, frame, bearings, sump and drive shaft all housed within a casing which is releasably connected to the engine such that the entire module including turbine, frame, bearings, sump and drive shaft may be readily removed and replaced by simply disconnecting the module casing from the engine. The entire operation may be accomplished without having to remove the engine from its associated aircraft.

Thermal response turbine shroud

Abstract: In a turbine engine the vanes and shrouds around the turbine blade tips are constructed to provide for radial positioning and axial movement. The shroud for the first turbine stage includes a growth control ring having a low expansion material while a high expansion material is used for the shroud. In order to maintain the desired temperature of the control ring, a heat shield is provided. All of the cooling air for the first and second vane is routed through the control ring. The second vane has a floating seal which can grow outwardly against the inner platforms of the vane. The invention described herein was made in the course of or under a contract with the Department of the Army.

System and method employing a digital computer for automatically synchronizing a gas turbine or other electric power plant generator with a power system

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. Automatic synchronization is achieved with a hybrid subsystem which includes the programmed computer and external phase detection circuitry. An automatic synchronization program for the computer is divided into rough speed and voltage matching, fine speed matching and breaker closure subprograms.

Heat transfer in a channel with a porous wall for turbine cooling application

Abstract: A method of cooling turbine blades internally by continuous injection through an interior baffle is analyzed. The analytical model consists of a two-dimensional channel formed by a solid wall (blade surface) and a porous plate (injection source). Based on incompressible- and laminar-flow assumptions, the velocity and the temperature fields are determined. The Nusselt numbers for a power-law surface-temperature variation are obtained and expressed in terms of the Prandtl and the Reynolds numbers. A related problem of cooling the turbine disk is also solved.

Fluidized bed powerplant with helium circuit, indirect heat exchange and compressed air bypass control

Abstract: A power unit consists basically of two gas turbine engines. In the first which is a closed cycle the working fluid (helium) is heated by passing it through a duct embedded in a fluidized bed. The exhaust gas is passed through a conventional heat exchanger before being returned to the compressor. In the second engine, consisting of a compressor and a turbine, air from the compressor is passed through the particulate material of the fluidised bed with fuel which maintains combustion in the fluidised bed. The exhaust gas from the turbine of the second engine is passed through a conventional heat exchanger and then to atmosphere. The two engines each drive an alternator.

Turbojet engine for vertical or short take-off and landing airplanes

Abstract: A turbojet engine arrangement, especially for use with vertical or short take-off and landing airplanes of the type having jet deflector devices separate from the basic engine thrust nozzle for amplifying thrust and lift at least during take-off and landing of the airplane. The arrangement includes a low-pressure turbine arranged downstream of the exhaust gas stream of the basic engine which is connected to a low pressure compressor arranged upstream of the forward most compressor of the basic engine. Control flaps are provided in the exhaust gas stream for selectively directing the basic engine exhaust gas stream to and away from the low pressure turbine. At least a portion of the air outlet of the low pressure compressor is directed to said deflector devices for amplifying thrust and lift when the exhaust gas stream is in communication with the low pressure turbine. In order to minimize disruption of inlet air to the basic engine, the low pressure compressor blades are pivotable into a neutral position, or alternatively are arranged outwardly of the inlet to the basic engine at the ends of non-flow disrupting radially extending spokes. Additional heating means for heating the exhaust gases leading to the low pressure turbine may also be provided.

On-line monitoring of steam turbine performance

Abstract: On-line monitoring of system, component and instrumentation performance is provided for the secondary cycle of a nuclear fueled electric power generation system. The performance figures are periodically calculated and compared with bogie figures by a programmed digital computer which prints out the results at intervals and on demand. Calculations of parameters for portions of the turbine system operating in the wet steam region are made through successive iterations based on assumed values and convergence steering data generated from heat or flow balances around adjacent components. A two step input reasonability check identifies, and under certain conditions substitutes for, abnormal values of the analog signals supplied to the digital computer from the plant secondary cycle.

System and method for operating a steam turbine with digital computer control and with improved monitoring

Abstract: A steam generator in an electric power generating system is controlled by controlling turbine steam flow with control signals generated by a programmed digital computer system during startup, synchronization and load operation. The digital computer control signals are generated as a function of monitored turbine system conditions and parameters, the digital computer having means for interrupting the normal computing of the control signals when predetermined operating conditions are monitored. Turbine system parameter signals are periodically scanned and operated on so as to condition them for use in generating the control signals.

Design and fabrication of the Brayton rotating unit

Abstract: The Brayton rotating unit (BRU), operating on a gas bearing system, has been designed, fabricated, and demonstrated for use in a closed Brayton cycle space power conversion system. The BRU uses a binary mixture of xenon and helium (molecular weight, 83.8) as the cycle working fluid and bearing lubricating medium and was designed to produce from 2.25 to 10.5 kw sub e of 1200 Hz three-phase electrical power. The single-shaft rotating assembly operates at a design speed of 36,000 rpm and comprises a radial single-stage compressor, a four-pole Rice alternator rotor, and a radial inflow turbine. Four units, a dynamic simulator and three component research packages, were supplied to the NASA Lewis Research Center for performance testing and further development.

Hydrodynamic device with slipping mechanical clutch

Abstract: A hydrodynamic device having an impeller, a turbine and a clutch for providing a slipping mechanical drive between the turbine and impeller in addition to the normal hydraulic drive therebetween wherein the clutch is engaged with fluid pressure derived from the pressure within the hydrodynamic device and is controlled by a valve operated by thrust on the turbine to maintain a constant speed differential between the turbine and impeller regardless of input torque.

System for the introduction of coolant into open-circuit cooled turbine buckets

Abstract: An improved coolant distribution system is described for the introduction of liquid coolant into the open-circuit cooling channels of a turbine bucket. Liquid coolant is transported by centrifugal force from the gutter to a pool located at the underside of the platform, the liquid entering the pool beneath the surface thereof. At least one weir is formed in the pool periphery for controlled distribution of the coolant from the pool to cooling channels in one or more turbine buckets.

Regenerative air-cooled gas turbine engine

Abstract: A regenerative air-cooled gas turbine engine, particularly applicable to and adequately clean burning for automotive and like applications requiring small size at a power rating in the 100-400 h.p. range. The engine is characterized by having the compressor, combustor, drive and power turbines, and regenerator all concentric with the longitudinal axis. The cool air supplied from the compressor to the regenerator passes in a tubular shroud-like flow which surrounds all but the compressor end of the engine and thus encloses the hot section of the engine. Cool air direct from the compressor output is ducted to the combustor and pre-mixed with run fuel supplied by a slinger which separately introduces run fuel and start/idle fuel, the pressure of the latter being boosted by a damper bearing acting as a fuel pump. Simplicity and low manufacturing cost are achieved by having substantially all gas flow confining surfaces in the form of surfaces of revolution. Cooling of nozzle vanes and the drive turbine impeller blades by air ducted from the tubular flow allows turbine gas inlet temperatures of 2,200* F. and higher. The regenerator is of the rotary disc type and has low cost, easily maintained non-rubbing seals.

Sliding vane rotary engines and process for obtaining high torque power

Abstract: The process consists in obtaining high torque, rotary power from initial (high energy) fragments of expansion-produced work which is obtained by allowing just a limited pressure-drop of successive segments of a highly expansible gas. The rest of the work which could be obtained from more complete expansion may be extracted in some other way, as by segmental expansion in successive chambers and/or by it driving a turbine, and then these secondary outputs may be added to the first. Thus, in comparison with the output curve of the full stroke of a piston engine, here only the initial, nearly vertical segment of the total expansion curve is ''''severed'''' from the whole and is used to pace at high torque, a rotary drive shaft. Structurally, this is by the use of one or more successive, shallow, arcuately elongated, curcumferential-stepwise expansion chambers in a sliding vane, rotary engine, in place of the wedge-shaped chambers of the past. The latter resulted in low-torque output partly because they tried to expose as large as possible a contact area of the sliding vane, and the associated outward or radial gas-expansion in the wedge-chamber produced no obtainable work from such radial movement; also, the intended, nearly complete gas-expansion resulted in an ''''average'''' low-torque output because most of it was obtained from the flat end of the pressure-volume curve. The present process is applicable to both internal combustion and non-combustion (e.g. compressed air or steam) rotary engines of the sliding vane type, for which several new constructions are provided. Advantage is also obtained by use of a molded carbon facing for the rotor and the combustion chambers.

Power augmenter bucket tip construction for open-circuit liquid cooled turbines

Abstract: Nozzle construction is disposed in the passage employed for the discharge of coolant flow from an open-circuit liquid cooled gas turbine. This improved construction relief upon for the recovery of reaction energy from the coolant is shown applied to both unshrouded and shrouded turbine buckets.

Device for automatically regulating the operation of a drilling turbine

Abstract: A device for automatically regulating the operation of a drilling turbine which drives a tool and is supplied with hydraulic fluid at an essentially constant rate of flow from a source of fluid. The device includes a duct in the form of a bore provided in the shaft of the turbine wherein the lower part of the bore terminates in the immediate vicinity of the tool, a first communicating member directly connecting the source of fluid with an inlet of the turbine to provide a flow path for the hydraulic fluid therethrough and a second communicating member for providing a flow path for hydraulic fluid to the tool. The second communicating member includes at least one orifice having a variable cross section for communicating between the inlet of the turbine and the upper end of the duct, the cross section being variable in accordance with an operating parameter of the turbine to regulate the flow of hydraulic fluid to the inlet of the turbine and to the tool.

Effects of specific speed on experimental performance of a radial-inflow turbine

Abstract: Specific speed effects on radial inflow turbine performance using different rotor configurations

Measurements Concerning the Influence of Surface Roughness and Profile Changes on the Performance of Gas Turbines

Abstract: During operation the blading of turbines undergoes certain changes. Corrosion, erosion, and contamination cause deterioration of the surface quality and blade profile changes. As a result, the performance characteristics of the turbine, especially the efficiency, change during operation. Through measurements on a four-stage air turbine with artificially roughened blade surfaces and thinned and thickened profiles which simulate the effects of corrosion and pollution respectively, it has been possible to ascertain the influence of these profile changes on the flow conditions in the turbine. This paper shows the measuring results which are representative of the effects of surface roughness and profile changes.

Fluid power drive system

Abstract: A fluid power drive system supplying pressurized fluid for operating pneumatic motors or other fluid responsive devices using a fluid compressor and turbine engine to develop pressurized fluid, the exhaust fluid from the turbine providing power for such pneumatic motors. The external work required to drive the compressor and turbine engine may be supplemented using a regenerative feedback apparatus including a second compressor and turbine combination of an idle turbine, each being driven by excess pressurized fluid not required by the pneumatic motors and released by a variable pressure relief mechanism.

Control for auxiliary power unit

Abstract: A control for a free turbine type of power plant utilized as an auxiliary power unit for aircraft generating electricity, supplying pneumatics and/or hydraulic pressure, maintains turbine speed at a constant value by modulaing engine power and compressor load independently of each other.

Gas turbine engine

Abstract: A high speed rotating unit which combines the Brayton cycle functions of mixing fuel and air, centrifugal compression of the combustible mixture, ignition of the said combustible mixture, containment of the products of combustion and utilization of the kinetic energy developed through a unique turbine blading and power take-off.