Showing papers on "Turbine published in 1977"

Aircraft Engines and Gas Turbines

Abstract: Part 1 Introduction to concepts: thermal efficiency propulsive efficiency specific impulse and range ramjets turbojets turbofans turboprops and other shaft engines - regeneration stationary gas turbines - topping energy exchange, Mach number, and Reynolds number stresses noise thrust and drag fuels and propellants some engines in cutaway. Part 2 Ideal cycle analysis - trends: stagnation temperature and pressure the ramjet the turbojet the afterburning turbojet the turbofan the afterburning turbofan the turboprop thrust lapse cooling cycles the regenerative gas turbine gas turbines for topping the importance of turbine inlet temperature. Part 3 Cycle analysis with losses: variation in gas properties diffuser pressure recovery compressor and turbine efficiencies burner efficiency and pressure loss imperfect expansion loss heat exchanger effectivness and pressure loss turbojet with losses turbofan with losses regenerated gas turbine with losses combined gas turbine-steam cycles with losses. Part 4 Nonrotating components: topics in gas dynamics diffusers exhaust nozzles combustors and afterburners. Part 5 Compressors and fans: energy exchange, rotor to fluid compressor geometry and the flow pattern design choices based on blade section performance details of flow in transonic compressors stage performance - corrected parameters multi-stage compressors compressor and compression system stability centrifugal compressors supersonic-throughflow fan. Part 6 Turbines: turbine stage characteristics turbine blading turbine cooling turbine design systems turbine similarity. Part 7 Engine structures: centrifugal stresses gas bending loads on blades thermal stresses critical speeds and vibration blade flutter bearings engine arrangement and static structure. Part 8 Component matching and engine performance: compressor-turbine matching - the gas generator matching the gas generator and the nozzle multi-spool matching engine-inlet matching and distortion overall performance control and acceleration. Part 9 Aircraft engine noise: noise sources - unsteady flow jet noise turbomachinery noise noise measurement and rules. Part 10 Hypersonic engines: hypersonic inlets heat addition in high-speed flow heat release due to chemical reactions nozzle flow fuel injection and mixing quantitative discussion of scramjet performance cooling the scramjet the air turborocket the liquid-air collection engine. Part 11 Propulsion systems analysis: takeoff climb and acceleration cruise maneuvering.

Cooling air cooler for a gas turbofan engine

Abstract: An air-to-air heat exchanger is provided for a gas turbofan engine to significantly reduce the quantity of cooling air that is presently needed to effectively cool the hot turbine parts. Typically, the turbine is internally cooled with air bled from the compressor which, though cooler than the turbine, has been heated due to the work done on it by the compressor. In accordance with the present invention, the heat exchanger is located internally of the bypass duct to place in heat exchange relationship a captured portion of the relatively cool bypass flow and this warmer compressor bleed air, thereby cooling the turbine coolant and significantly reducing the amount of such coolant required. This results in a decrease in engine specific fuel consumption.

The interaction of entropy fluctuations with turbine blade rows; a mechanism of turbojet engine noise

Abstract: The theory relating to the interaction of entropy fluctuations ('hot spots'), as well as vorticity and pressure, with blade rows is described. A basic feature of the model is that the blade rows have blades of sufficiently short chord that this is negligible in comparison with the wavelength of the disturbances. For the interaction of entropy with a blade row to be important, it is essential that the steady pressure change across the blade row should be large, although all unsteady perturbations are assumed small. A number of idealized examples have been calculated, beginning with isolated blade rows, progressing to single and then to several turbine stages. Finally, the model has been used to predict the low-frequency rearward-radiated acoustic power from a commercial turbojet engine. Following several assumptions, together with considerable empirical data, the correct trend and level are predicted, suggesting the mechanism to be important at low jet velocities.

Submarine turbine power plant

Abstract: A power plant for the generation of electricity from the flow of water currents uses turbine wheels within nozzles submerged in the water current, anchored to the bottom of the water course, as for example, the ocean, and self-buoyed to a level well below the water surface Pairs of counter-rotating turbines are supported by their rims, which bear against friction drive wheels, which in turn drive electrical generators contained in water-tight machine rooms within the wall of the nozzle A structural design is disclosed, providing for the building of modules of the nozzle ashore, which modules may then be barged to the deep-water site for assembly into the whole power plant

System for the obtainment and the regulation of energy starting from air, sea and river currents

Abstract: A system for obtaining and regulating energy from the air or sea and river currents includes a cyclone converter formed by three concentric rotating bodies, either on shafts or cylindrical rails or the like. Fixed rollers or other electromagnetic systems permit the rotation of the group around an imaginary or actual geometrical shaft. The outside body is self-orientating with its main components and deflectors on rotating components or a base sliding rail. The intermediate concentric body or turbine is formed by rings and vanes and a system of rollers or electro-magnetic supports which are inside or outside the turbine. The inside body or diffuser rotates concentrically in a reverse direction to the turbine and has vanes of opposite complementary angles.

Method of manufacturing a hybrid turbine rotor

Abstract: A method for manufacturing a turbine rotor assembly from dissimilar materials includes the step of preforming a turbine disc of powdered metal by direct hot isostatic pressing; machining the OD of the disc rim to an exact dimension; prefabricating a ring of airfoil elements having a circular rim with a machined ID therein fit to the OD of the turbine disc; sealing joint lines on side surfaces of the joined parts to create a vacuum at the interface with a high melt temperature sealant; thereafter diffusion bonding the joined and sealed parts by hot isostatically pressing them at temperatures in excess of 1500° F. and under fluid pressure directly applied to the parts in excess of 1000 psi to press the ring ID into intimate contact with the OD of the disc until the dissimilar materials are diffusion bonded to form a high strength butt joint therebetween.

Wind turbine apparatus

Abstract: The Specification discloses a segmented wind turbine which can be added to incrementally to increase the driving force and power generation of the machine. By this means the smaller diameter rotors that are more easily handled and that put the minimum of stress on the wind turbine apparatus can be used in series to achieve the power output desired. Each segment has a venturi means incorporated into the elements of the apparatus to enhance the apparent wind speed. Also disclosed are novel means for operatively supporting the moving parts of the apparatus. In a preferred embodiment an exoskeletal frame is made in segments that can be stacked one upon the other. Each segment of frame has arms which converge inwardly toward the axial center of the apparatus. There a hoop connects the ends of the inwardly converging arms and defines an axial aperture. Inside this axial aperture a segment of drive shaft and a concentric collar are supported by thrust bearings which are in turn supported by the concentric hoop attached to the arms of the frame. Each set of arms and the associated bearings support the drive shaft, a rotor on the drive shaft, and a wind shield surrounding the rotor immediately above the arms. The wind shield is of a novel structure, having two spaced side walls which define openings for receiving wind through the rotors and discharging the wind. One of the walls forms a venturi with the rotor.

Gas turbine engine having bleed apparatus with dynamic pressure recovery

Abstract: A gas turbine engine has conduits leading from the compressor to the turbine for bleeding a portion of compressor air through the turbine blades for cooling or other purposes. A radial pump in the conduits formed by a tangential accelerator and a rotating diffuser transmits the air from the non-rotating environment in the engine to the rotating environment of the turbine rotor. The tangential accelerator accelerates the bleed air to a tangential speed higher than that of the rotor, and the radial diffuser is designed to recover the dynamic pressure or relative velocity of the air over the rotor.

Gas turbine power plant control apparatus including an ambient temperature responsive control system

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

Eddy current probe for inspecting interiors of gas turbines, said probe having pivotal adjustments and a borescope

Abstract: An eddy-current crack detection probe is described which allows inspection of turbomachinery parts of conductive material for cracks without removal of the parts to be inspected from the machine or disassembly of the casings normally restricting physical access to these parts. The crack detection probe is particularly useful for field inspections of the trailing edges of turbine buckets of a gas turbine for cracks not readily detectable by optical techniques. The probe, which is insertable through a small opening in the turbomachine casing and thereafter can be remotely manipulated to assume an appropriate inspection position, includes a small eddy-current sensor and may include a borescope for remote viewing of the sensor and turbine bucket edge to be inspected.

Composite seal for turbomachinery

Abstract: A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor blades. A compliant backing surrounds the shroud. The backing may be made of corrugated sheets or the like with adjacent layers having off-set corrugations, with axes of the folds parallel to the rotor axis. The sheets may be bonded together at points of contact by brazing, welding or the like. In another embodiment a compliant material is covered with a thin ductile layer. A mounting fixture surrounds the backing.

Compact shrouds for wind turbines

Abstract: As part of a large project aimed at finding the optimal configuration for an aerogenerator to exploit wind power, an investigation was launched to find the most compact shroud possible. The dominant contributor to the shroud length is the structure downstream of the turbine (the diffuser). This component has an ever increasing cross-section as one progresses downstream, however, fast rate of area divergence will cause flow separation and the significant reduction in output power associated with it. It is the purpose of the present paper to demonstrate ways to overcome this difficulty. This can be achieved either by proper diversion and introduction of the shroud's external flow into the diffuser's inner boundary layer or alternatively, by the usage of a ring-flap.

Partial oxidation process with production of power

Abstract: Power is developed by an expansion turbine in which the working fluid is a gaseous mixture comprising all of the hot raw gas stream leaving an unpacked partial oxidation gas generator, after removing if present a portion of the entrained solids, in admixture with a temperature moderating stream. A molal increase is associated with the partial oxidation process. Power is obtained from this molal increase in addition to the power obtained from the elevated pressure and sensible heat in the hot raw partial oxidation product gas. The temperature moderating stream may comprise a recycle portion of the turbine exhaust gas stream after being cooled, cleaned, optionally water-gas shifted or purified, or both, and recompressed. Alternatively, the recycle gas stream may be mixed with water, steam, or both. In one embodiment the temperature moderating stream comprises liquid water or condensate produced in the process. Auxiliary gas compressors for recompressing said recycle gas, and optionally for compressing a free-oxygen containing gas for use in the gas generation zone may be driven by said expansion turbine. Similarly, an electric generator may be coupled to the turbine shaft.

Combustion chamber for gas turbines

Abstract: A combustion chamber for a gas turbine is provided with a prechamber connected at the input end of the flame tube. The dimensions of the flame tube and prechamber, and the location of the air inlet openings are selected so that the flame in the flame tube flashes back and burns as a stable rich flame in the prechamber when the turbine is in a high-load condition. The result is a variation in the combustion properties of the chamber which reduces pollutant emission levels over a wide range of engine load conditions.

Solar heat supplemented convection air stack with turbine blades

Abstract: A high rise building is provided including upstanding peripheral wall portions and at least one of the peripheral wall portions includes an upstanding air flow passage extending therealong. Horizontally outwardly projecting and downwardly opening hollow snout-like shrouds define air inlets opening outwardly and downwardly along the one upstanding peripheral wall portion and inwardly into the air flow passage at points spaced vertically therealong. A rotary turbine including an inlet and outlet is supported from an upper portion of the building and the upper end portion of the air flow passage is communicated with the inlet of the turbine. The turbine includes a rotary output shaft and a generator is driven from the rotary output shaft of the turbine for generating electrical current.

Cooling apparatus for a bearing in a gas turbine

Abstract: This invention relates to a method of thermally isolating a bearing located near the combustion region in a gas turbine. Air is bled from an intermediate stage of the compressor turbine and is arranged to be fed to the central pipe of a coaxial piping arrangement which leads to the bearing housing. The housing for the bearing is arranged to have cooling air passages located therein to allow the air to circulate around and thus isolate the various parts of the bearing from the hot ambient. The air which has thereby acquired heat is subsequently lead back to the coaxial piping arrangement and is fed outwardly through the turbine in the space between the outer pipe and the central pipe.

Seal clearance control system for a gas turbine

Abstract: A gas turbine engine has an engine casing surrounding the turbine section and an internal chamber or jacket which separates the casing from blade tip seals supported by the casing. To maintain an adequate clearance between the turbine blades and the seals during engine startup and acceleration, a portion of the hot combustion gases passing through the turbine blades is bled through the chamber in heat exchange relationship with the casing. The hot gases expand the casing at a faster rate than otherwise to approximate the thermal growth rate of the turbine rotor and maintain a adequate clearance between the turbine blade tips and seals. During steady-state operation relatively cool air bled from the compressor is ducted through the chamber to cool the engine casing and hold the proper clearance between the blades and the seals. A valve connected with the chamber controls the flow of hot combustion gases and cool compressor air through the chamber so that the engine casing can be expanded or contracted to control the blade clearance.

Internal combustion engine with afterburning and catalytic reaction in a supercharger turbine casing

Abstract: To remove pollutants in the exhaust gases from a liquid fuel driven engine, a turbosupercharger, including a turbine and a compressor, is combined with the engine to provide both afterburning and catalytic oxidation. The exhaust gases are accumulated to provide combustion in advance of the turbine. Further, air is branched off from the compressor and mixed with the gases flowing through the turbine to afford combustion of the gases after they pass through the turbine. Catalytically active surfaces are located within the turbine for the reduction of nitric oxides.

Double reheat hydrogen/oxygen combustion turbine system

Abstract: A gas turbine power generating system comprising, in the preferred embodiment, three gas turbine engines in series-connected flow communication employing high pressure hydrogen and oxygen as the fuel. Pre-heated pressurized steam (or a steam and water mixture) is fed to the initial gas turbine combustor for combustion coolant. Steam, consisting of the products of combustion plus the vaporized coolant, is exhausted from the first turbine into the combustor of the next turbine for re-heating via the combustion therein of the high pressure hydrogen and oxygen. The exhaust steam from the intermediate turbine is in turn re-heated in the combustor of the final turbine. The final exhaust steam is then passed through a recuperative heat exchanger to pre-heat the pressurized cooling water so that, when injected into the first combustor, it is vaporized prior to entering the first turbine.

Control for gas turbine engine

Abstract: Increased thrust during the transonic flight mode of an aircraft powered by a gas turbine engine is realized by a closed loop control that closes the loop on the pressure ratio across the fan by adjusting fuel flow and/or exhaust nozzle area in a turbofan, variable exhaust nozzle installation. Fan pressure ratio is scheduled as a function of corrected fan speed and actual pressure ratio provides an error signal to readjust engine operation to null out this error signal. A turbine inlet temperature limit signal is generated to prevent inadvertent overheating and it or this pressure ratio error signal is selected for providing the lower fuel flow value.

Combustor liner for gas turbine engine

Abstract: This invention relates to an improvement of the cooling air flow distribution in proximity to the combustion and dilution air holes of a combustor liner fabricated from Finwall® material for a turbine type power plant.

Apparatus for the treatment of gas turbine exhaust gas

Abstract: A reducing agent such as ammonia, urea or hydrazine effecting selective reduction reaction with an exhaust gas from a gas turbine is injected into a duct of the turbine along with water, and at the same time compressed air from a compressor for the turbine is jetted in the duct to atomize the reducing agent. An amount of the water is controlled so that the surrounding temperature will be suitable for reduction of nitrogen oxides of the exhaust gas. The atomized reducing agent flowing in the duct is decelerated by silencers disposed in the duct, especially by a particular arrangement thereof, so that the reducing agent will be in good contact with the exhaust gas to sufficiently reduce the nitrogen oxides. Catalyst layers are used according to kinds of the reducing agent. The catalyst layers are disposed in the silencers or at the positions that the silencers are disposed.

Wind rotor automatic air brake

Abstract: A spring-loaded pivoting end plate that is hinged such that it is deployed by centrifugal force into the airstream to thereby act as an aerodynamic brake for wind turbines in overspeed conditions. The brake has a stationary portion fixed on the tip of the turbine rotor and a pivoting portion hinged for movement with respect to the fixed portion. The longitudinal centerline of the brake coincides with the chord line of the turbine blade and the pivoting movement is about a hinge axis that is normal to the rotational plane of the turbine. The planform of the brake has a low aspect ratio shape with the ratio of the fore and aft chordwise length to the width being one or greater. The edges of the brake in the normal running condition extend beyond the contour of the turbine blade to serve as an end plate such that the aerodynamic efficiency of the blade is improved thereby.

Gas turbine engine and means for cooling same

Abstract: The turbine blades of a gas turbine engine are individually cooled through the internal circulation of a fluid coolant by the thermosiphon principle. Each turbine blade has associated therewith a closed-loop coolant passageway which is rotatable with the turbine rotor disk and which, in one embodiment, passes through a heat exchanger borne by, and rotatable with, a rotatable lubrication duct. The blade internal coolant is placed in heat exchange relationship with engine lubrication oil within the heat exchanger. The heated lubrication oil is then placed in heat exchange relationship with the engine fuel and the fuel thus heated is burned in the combustor, thereby returning at least a portion of the heat removed from the turbine blades to the engine power cycle. The cooling system is designed for simplified blade removal and replacement and the entire turbine can be removed from the engine as a sealed unit. A secondary cooling system is provided as a backup in the unlikely event that cooling effectiveness of one or more of the blade coolant loop passageways is lost.

Effect of generalized wind characteristics on annual power estimates from wind turbine generators

Abstract: A technique is presented for estimating the average power output of a wind turbine using, as the wind characteristic input, only the mean annual wind magnitude. Hourly wind speeds are assumed to have a Rayleigh frequency distribution which requires a single parameter input (e.g., the mean value, variance or higher moment values). Based upon a general shape, for the wind speed versus machine output, a generic set of curves is developed to estimate the average power output of wind turbines. Also, estimates of the percent of time the wind turbine would not produce power (percent down time) and the percent of time the wind turbine would be operating at its rated power are presented.

Turbine shroud support

Abstract: Hot gas recirculation is eliminated between the trailing edge of a turbine shroud and the leading edge of a downstream vane by a tongue-and-groove interconnection between the two parts and a passage of cooling air through the interconnection to exhaust against the vane outer band and flow into the main gas stream. The shroud with its supporting structure is thereby maintained at substantially uniform temperatures around its circumference so as to present a round, close-tolerance relationship to its circumscribed turbine blade row.

Power generation from refinery waste heat streams

Abstract: The integration of a petroleum refinery, or a petrochemical complex, with an off-site power facility in which the latter provides a vaporizable coolant for vaporization in the former. Vaporization is effected through indirect contact with one or more waste heat streams; the resulting vapors are expanded through a turbine, to a lower pressure, from the resulting motion of which power is generated. In most instances, the process generates more power than its connected load. Preferably, the coolant is indirectly contacted, at elevated pressure, with a plurality of refinery process streams in series and in the order of increasing temperature. Resulting vaporized coolant phases are passed through individual turbines, or through different stages of a multiple-stage turbine.

Vane rotator assembly for a gas turbine engine

Abstract: This invention relates to a method of moving a set of adjustable trailing vanes in a gas turbine engine of the "split-shaft" type. The vanes are moved by an adjusting ring which is made to completely encircle the casing of the turbine and connect to each vane by means of a rotator assembly. Provision is made to allow for connection of the turbine casing so that the binding or flexing of the adjustor ring assembly during thermal cycling is avoided. A series of pitman arms are pivotally interconnected between the adjustor ring assembly and each vane rotator assembly. The vane rotator assembly is provided to intercouple the adjustor ring assembly to each pivoting vane while at the same time providing some radial flexibility for the vane itself to prevent binding of the blade and actuator during thermal cycling. Provision is also made to bias each pivoting vane in the particular direction in the turbine during the operation of the turbine.