Showing papers on "Turbine published in 1973"

Gas Path Analysis Applied to Turbine Engine Condition Monitoring

Abstract: An approach is presented to turbine engine gas path analysis and monitoring, which permits the isolation of single or simultaneous multiple engine faults, with a quantitative assessment of their relative' severity. The software approach is described, showing features of its mathematical development and thermodynamic justification. Measureable engine parameters are treated as dependent variables, changes in which are mathematically interrelated to changes in component performance brought about by physical engine faults. Typical results are presented from real programs, wherein engine data were analyzed to provide meaningful and verified diagnoses of single and multiple engine faults.

Turbine rotor blade cooling and sealing system

Abstract: An assembly for sealing the root portions of gas turbine rotor blades of the side entry type into a rotor. The assembly also provides cooling for the blades. A radially directed three-sided channel disposed on the upstream side of the rotor near its periphery forces cooling fluid radially outward to a chamber beneath each blade root. The rotor, when rotating, causes the channel to act as a pump due to centrifugal force imparted to the cooling fluid. The coolant fluid is forced out the channel and into the chamber, then the coolant fluid is discharged radially through the blade root. A chamber sealing plate prevents axial leakage of the coolant past the downstream side of the blade root. The chamber sealing plate is fitted into a groove on the periphery of the rotor radially inwardly of and near the downstream end of the blade root. The sealing plate is notched, and interlocks with a corresponding tab in the downstream base of the blade root, which prevents the seal plates from moving circumferentially during turbine operation. The seal plate is further restrained axially by contact with an exhaust sealing and locking plate that is mounted in another peripheral groove downstream of the chamber sealing plate. The exhaust plate seals the downstream side of the blade entry channels, and locks the blades into the rotor.

Method of effecting fast turbine valving for improvement of power system stability

Abstract: As an improved way of effecting fast valving of turbines of power system steam-electric generating units for the purpose of improving the stability of power transmission over transmission circuits to which their generators make connection .Iadd., .Iaddend.when stability is threatened by line faults and certain other stability endangering events, and in which intercept valves are rapidly closed on a momentary basis, the procedure of intercept valve closure is supplemented by simultaneously initiating turbine and steam supply source control programs, which (a) .[.being.]. .Iadd.bring .Iaddend.into effect a sustained reduction in turbine driving power via employment of measures which may include full closing of some or all control valves and/or employment of preprogrammed control valve repositioning, with provision to automatically divert high pressure steam to the condenser or to atmosphere as a way to prevent discharge of steam through high pressure safety valves. (b) bring into effect a rapidly executed process of reduction of rate of generation of steam within steam supply sources, and (c) initiate a control program that effects a predetermined degree of partial reopening of intercept valves early in the course of the generator rotor's first backward swing, following which intercept valves are further opened and control valve positions optionally revised in preprogrammed ways with the overall effect that in the period following the first forward swing the magnitude of turbine driving power is caused to hold below the value that applied prior to the event that initiated fast valving and to at most only briefly exceed a final sustained value that can be preset.

Turbine coolant flow system

Abstract: In a turbine engine compressed air is delivered through a diffuser to a burner section and then through a turbine section. A portion of the compressed air from said diffuser is removed by an annular center body manifold and directed by hollow struts inwardly to an annular passageway where the compressed air flow is taken to the forward part of the turbine section. The flow from the annular passageway is then directed into a passageway having directing vanes for imparting a desired velocity and direction to the existing flow so as to be compatible with the rotating turbine disk onto which it flows. This air is then directed to cool blades on that disk and also passed through that disk to be directed to turbine blades on the next disk. The invention herein described was made in the course of or under a contract with the Department of the Air Force.

Brittle Materials Design, High Temperature Gas Turbine

Abstract: : The demonstration of uncooled brittle materials in structural applications at 2500 F is the objective of the 'Brittle Materials Design, High Temperature Gas Turbine' program. Ford Motor Company, the contractor, will utilize a small vehicular gas turbine while Westinghouse, the subcontractor, will use a large stationary gas turbine. A significant achievement in the vehicular turbine project was the successful engine test, 175 hours at 1930 F, of a silicon nitride stator. Durability testing on a nose cone was extended to 246 hours, equalling the previously demonstrated durability of 245 hours on 1st and 2nd stage rotor tip shrouds. A 'Refel' silicon carbide combustor previously demonstrated 171 hours durability, crack-free, including 20 hours at 2500F. Two additional combustors of the same material were tested for 10 hours each. Eight hours of testing the stationary ceramic flowpath at 2500 F were accumulated; non-catastrophic cracks occurred in the nosecone and stator after surviving three hours crack-free. Two stator vanes survived 1000 cycles to 2500-2600 F plus 3720 cycles to 2900 F in the thermal shock rig. A concentrated effort on turbine rotor fabrication development was initiated. Improvements in the rotor fabrication processes have been made. Reduction of the MgO content increased the hot strength of the hot-pressed silicon nitride rotor hub material. Over 500 rotor blade rings were fabricated using the injection molding process and some high density rotor blade rings were also fabricated by slip-casting.

Turbofan engine having counterrotating compressor and turbine elements and unique fan disposition

Abstract: A turbofan engine is provided with a compressor and a turbine, all of the bladed stages of the turbine and substantially all of the bladed stages of the compressor being rotor stages. Adjacent rotor stages within the compressor and the turbine are relatively counterrotating. The engine has three independently rotatable shafts connecting respectively three sets of bladed stages of the turbine with three sets of bladed stages of the compressor to form three engine spools. A bladed fan occupying an annular duct substantially surrounding the compressor is driven by the intermediate of the three spools and is disposed near the axial center of the compressor. A quarterstage inlet fan, disposed within the duct upstream of the first fan, is driven by the radially innermost shaft, and has a predetermined length such as to maintain a substantial torque balance between the counterrotating rotors at a preselected rotary velocity of the innermost shaft.

Screen apparatus for air inlet

Abstract: Screen apparatus for the air inlet of a turbine engine such as an aircraft power plant or the like. The screen apparatus is particularly useful for preventing ingestion of birds into aircraft jet engines. A screen extends outwardly from the air inlet of the engine to define an exterior surface providing an oblique angle relative to the nominal path of the engine through the air. Birds or other foreign objects which strike the screen are deflected away from the screen and the air inlet by the contact with the oblique angle. A solid nosecone at the forward end of the screen provides an area of relatively high air pressure which tends to deflect objects away from straight-on impact with the screen. The apertured exterior surface of the screen apparatus has an aggregate aperture area equal to or exceeding the air inlet area of the engine to permit unimpaired engine operation.

Dynamic Behavior of Solid Particles Suspended by Polluted Flow in a Turbine Stage

Abstract: The equations that govern the three dimensional motion of solid particles suspended by a compressible gas flow through a rotating cascade of a turbomachine are formulated. These equations are solved for the case of flow through a turbine stage. The solution takes into account the loss in particle momentum due to their collision with the turbine blades or casing. The dynamic characteristics of the solid particles; namely, their absolute trajectories, paths relative to the turbine rotor, velocity distributions, and the combined stage velocity diagrams, are calculated. The effects of changing the particles mean diameter, material density, and initial particle and gas velocities at the stator inlet on the dynamic characteristics of the solid particles are investigated. The results obtained from this study indicate the locations on the turbine blades subjected to severe erosion damage. Nomenclature a = particle absolute acceleration B = frame fixed in blades /# = angle between particle relative velocity and tangent to surface C = absolute velocity C" = absolute velocity component in the x,0 plane Cpg , = specific heat of gas at constant pressure

Dynamic Models of Turbine Generators Derived From Solid Rotor Equivalent Circuits

Abstract: A method is described for determining the structure and coefficients of dynamic models of turbogenerators from detailed equivalent circuits of the d-and q-axes of a solid rotor generator. These models are intended for analyses of power system dynamics in cases where it is desirable to have a very accurate representation of the synchronous machine. The models have been used to study power system hunting or dynamic stability, first swing or transient stability, load rejection overvoltages, resynchronization of cross-compound turbine-generator sets, field current and voltage during out-of-step operation, voltage dip and other phenomena associated with machine operation on power systems. The paper reviews some of the experience obtained in system studies and in comparisons between test results and computer simulations.

Stall warning system for a gas turbine engine

Abstract: A stall warning system for a gas turbine engine precludes the possibility of an erroneous indication of compressor stall by simultaneously monitoring the air pressure at the discharge end of the engine compressor together with the temperature of the turbine section of the engine. Initiation of the stall warning signal is made contingent upon the simultaneous receipt of signals indicative of both an abnormally low compressor discharge pressure and an abnormally high turbine temperature. In this manner an erroneous indication of compressor stall, as may occur during normal operation of the engine when the compressor discharge pressure is low, may be positively precluded.

System and method for starting, synchronizing and operating a steam turbine with digital computer control

Abstract: Steam flow and pressure conditions needed in a turbine to satisfy the speed and load demand of an electric power generating system are controlled by a programmed digital computer system during start-up, synchronization and load operation Manual backup control is provided for the computer control Throttle valve tests are provided under digital control and transfers are made to manual backup control if predetermined task errors occur

Thermo-electrically propelled motor-vehicle

Abstract: A motor vehicle with thermoelectrical drive, having driving means comprising a turbine which actuates an alternator feeding, through a set of rectifiers, at least one direct current electromotor providing for the vehicle traction. A buffer storage battery, connected to the supply of the motor(s), actuates said motor in alternative or in addition to the alternator actuated by the turbine, so that the vehicle may be also only electrically driven. The vehicle may be provided with a device, operatively connected to the turbine, and measuring in particular circumstances the pollution produced by the turbine when this is operating.

Self-trimming control for turbofan engines

Abstract: A twin spool turbofan engine control is designed which maintains engine thrust and stall margin at nominal levels as the operating characteristics of the engine high spool deteriorates with operating hours, increased altitude or increased power extraction. An electronic supervisory control monitors the high rotor speed and the fan turbine inlet temperature relationships for all engine power settings from intermediate to maximum, and the electronic supervisory control schedules are adjusted based upon shifts in the relationships. In one embodiment the fuel flow to the engine is trimmed in response to a desired fan turbine inlet temperature schedule determined as a function of engine inlet temperature and main burner pressure, the schedule being modified in response to the difference between operating high rotor speed and a reference rotor speed which in turn is a function of engine inlet temperature. In another embodiment the engine fuel flow is trimmed in response to a high rotor speed schedule determined as a function of engine inlet temperature and biased by the difference between a sensed fan turbine inlet temperature and a reference fan turbine inlet temperature. In both embodiments the area of a variable geometry nozzle in the engine is trimmed to modify the fan airflow.

Life prediction of turbine components: On-going studies at the NASA Lewis Research Center

Abstract: An overview is presented of the many studies at NASA-Lewis that form the turbine component life prediction program. This program has three phases: (1) development of life prediction methods for major failure modes through materials studies, (2) evaluation and improvement of these methods through a variety of burner rig studies on simulated components in research engines and advanced rigs. These three phases form a cooperative, interdisciplinary program. A bibliography of Lewis publications on fatigue, oxidation and coatings, and turbine engine alloys is included.

Pressurized serpentine cooling channel construction for open-circuit liquid cooled turbine buckets

Abstract: Individually fed convoluted cooling channels are provided for open-circuit liquid cooled turbine buckets. Each convoluted channel is fed liquid coolant directly from a gutter on the rotor rim via a coolant supply conduit. Openings to the coolant supply conduits are spaced at even intervals along the circumference of the gutter and a U-trap is located in each coolant supply conduit to provide a liquid seal to prevent the reverse flow of gas or vapor from the convoluted cooling channel pattern in flow communication therewith.

Reactor megawatt demand setter

Abstract: The electrical power output of a nuclear powered generating station, as requested by an operator or by an automatic dispatch system for the grid with which the station is associated, is controlled in a manner which insures that the nuclear steam supply system limits are not violated. The invention permits the nuclear powered generating unit to operate at maximum permissible power for the existing nuclear steam supply system conditions by exercising control over the unit turbine in such a manner that the rate of load change will be controlled as a function of the proximity of the actual load to the desired load and the rate of load increase will be algebraically limited by the proximity of the nuclear steam supply system conditions to the steam supply system operating limits. Additionally the turbine load will automatically be reduced when necessary at a rate which equals or exceeds a value which is commensurate with the magnitude of any violation of the steam supply system operating limits.

Plant unit master control for fossil fired boiler implemented with a digital computer

Abstract: An electric power plant, including a fossil fired boiler and a steam turbine, is operated by a control system including a plant unit master. The control system includes a boiler control for determining the inputs of fuel, air and water, and a turbine control for determining the position of the throttle valves introducing steam from the boiler to the turbine. The plant unit master provides a load demand reference in parallel to the boiler control and to the turbine control, whereby the turbine and the boiler are operated in a coordinated manner. Measuring means provide indications of throttle pressure, power generated by the system and turbine rotor speed. Distinct controllers, each including a controller and responsive to one of the aforementioned indications and its corresponding reference, modify the load demand reference before it is applied to the turbine control or to the boiler control. The above-described control system including the plant unit master, boiler control and turbine control is implemented by a single digital computer.

System and method for monitoring industrial gas turbine operating parameters and for providing gas turbine power plant control system inputs representative thereof

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 means. Control system inputs representative of current values of such variables are continuously available to provide positive highly responsive control over a broad range of gas turbine operating conditions. Predictable process sensor errors are effectively eliminated by means of programmed computer operations to thereby insure highly accurate control variable derivation essential to maintaining gas turbine operation at or near design limits.

Fast Turbine Valving

Abstract: The fact that, as a matter of necessity, power system steam turbines are in all cases equipped with control systems which include provision to close steam inlet valves rapidly on sudden loss of load as a way to suitably limit speed increase, implies that these systems are basically not difficult to modify so as to allow employment of fast valving as a way to maintain system stability despite the occurrence of a line fault or some other system stability endangering event.

Digital computer control system and method for monitoring and controlling operation of industrial gas turbine apparatus employing expanded parametric control algorithm

Abstract: A hybrid digital computer gas turbine power plant control system which may operate in a multiple control loop arrangement is provided with a plurality of process sensors at various operating cycle positions. Derivative inputs provide a basis for responsive control system variation of gas turbine parameters. Parametric control is maintained over generator and turbine subsystems during all modes of operations. More specifically, optimally arranged system thermocouples provide inputs from which temperature control variables are derived. Inlet guide vanes are positioned in response thereto to control exhaust gas temperatures while maintaining near optimum generator output.

Serpentine cooling channel construction for open-circuit liquid cooled turbine buckets

Abstract: Individually fed serpentine or spiraled cooling channels are provided for open-circuit liquid cooled turbine buckets. Each convoluted coolant channel is fed liquid coolant directly from a gutter on the rotor rim via a coolant supply conduit. Openings to the coolant supply conduits are preferably spaced at even intervals along the circumference of the gutter.

Gas turbine engine and counterflow heat exchanger with outer air passageway

Abstract: A gas turbine engine comprising a compressor, a turbine, and a burner. The turbine is interposed between the compressor and the burner. The exhaust gases of combustion from the turbine are reversed and moved axially while the air from the compressor is moved in a sinuous path in heat exchange relationship to the movement of the exhaust gases axially.

Leakage control structure

Abstract: An improved leakage control structure is provided between a bucket cover of a turbine and the surrounding diaphragm thereof to reduce leakage of the fluid flow in this area during operation of the turbine.

Gas turbine power plant control apparatus including a turbine load 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.

Thrust augmenting device for jet aircraft

Abstract: A dual set of counter-rotating impulse turbine wheels having short propeller blades about their periphery are disposed in the exhaust emitted by a jet engine to augment its thrust at lower subsonic speeds by extracting energy from the high velocity gases. The counter rotation minimizes torque loads. The turbine wheels may be closely mounted behind the engine and directly connected thereto or movably mounted for optional retraction out of the path of the exhaust at higher speeds when the jet engine is more efficient.

Electric power plant having a multiple computer system for redundant control of turbine and steam generator operation

Abstract: The electric power plant including a steam generator and a steam turbine is operated by a control system including two redundant digital computers. Switching circuitry is provided for coupling one of the computers through interface equipment to the steam generator and the turbine and a generator according to programmed computer control. A data link is established between the computers to transfer manual/automatic status and other needed data from the control computer to the standby computer. A system is provided for detecting when certain hardware and software malfunctions have occurred and for responsively transferring control to the standby computer. The standby computer is tracked to the control computer so that control computer transfer can be made reliably without disturbing the electric power generation process.

Influence of Fuels and Lubricants on Turbine Engine Design and Performance, Volume II. Fuel and Lubricant Analyses

Abstract: : An analytical study was conducted to determine the requirements for future fuels and lubricants research based on design studies of a high Mach number afterburning turbojet and a higher Mach number advanced multicycle turboramjet. Fuel and lubrication systems were defined, and computer models were developed for their thermal analyses. Fuel and lubricant stream temperature profiles were computed, and the effects of design modifications on these temperatures were evaluated. Fuel and lubricant temperatures were calculated for baseline missions, for steady-state flight envelope points, for alternate aircraft/engine interface fuel temperatures, and for transient maneuvers.

Turbine engine with integral compressor and alternator rotor

Abstract: A gas turbine engine in which the generator or alternator for supplying electrical requirements of the engine has its armature rotor integrally mounted on the forward end of the compressor shaft and driven thereby, the armature rotor serving as the locknut for the forward main bearing of the compressor shaft. The alternator or generator, with such auxiliary equipment as rectifier and voltage regulator, is thus housed within the main engine housing, eliminating the manufacturing expense and the complicated assembly problems of the additional housing pod, gear drive, and power takeoff used in the prior art.