Showing papers on "Ram air turbine published in 1997"

A variable speed wind turbine power control

Abstract: To optimize the power in a wind turbine, the speed of the turbine should be able to vary with the wind speed. A simple control scheme is proposed that will allow an induction motor to run a turbine at its maximum power coefficient. The control uses a standard V/Hz converter and controls the frequency to achieve the desired power at a given turbine speed.

Integrated air conditioning and power unit

Abstract: An integrated air conditioning and power unit is provided for use with an aircraft. The system includes an air turbine 42 having air passages connected to an engine 10 of the aircraft for receiving bleed air and/or ram air for driving the air turbine 42. A motor/generator 104 is drivingly connected to the air turbine 42. The motor/generator 104 is capable of drawing electricity from an aircraft primary power system for driving the motor or generating electricity which is delivered to the primary power system 108. An air compressor 54 is drivingly connected to the motor/generator 104 and is provided with an air passage which receives bleed air 32 and/or ram air 30 from the aircraft engine 10. A cooling system 71 is provided including a system compressor 81 drivingly connected to the motor/generator 104. A cooling system evaporator 70 and a condenser 92 are connected to the system compressor by fluid passages. The air compressor 54 includes an air outlet for providing pressurized air which is cooled by the cooling system.

Closed-loop air cooling system for a turbine engine

Abstract: Method and apparatus are disclosed for providing a closed-loop air cooling system for a turbine engine. The method and apparatus provide for bleeding pressurized air from a gas turbine engine compressor for use in cooling the turbine components. The compressed air is cascaded through the various stages of the turbine. At each stage a portion of the compressed air is returned to the compressor where useful work is recovered.

Design synthesis of oscillating water column wave energy converters: Performance matching:

Abstract: The matching of a Wells air turbine to an oscillating water column (OWC) is addressed, with particular reference to design synthesis at the Islay prototype wave power converter. The level o...

Ram air turbine system

Abstract: A ram air turbine includes a reaction turbine and an electrical generator that is driven by shaft power of the reaction turbine A scoop directs a flow of ram air to an inlet of the reaction turbine and creates a pressure head for the reaction turbine The reaction turbine and the scoop are contained entirely within a pod The ram air turbine further includes a turbocompressor, including a turbine stage and a compressor stage, which provides a stream of cooled air to equipment inside the pod The turbocompressor also reacts loads shed by the electrical generator

Hand held turbine powered extractor nozzle

Abstract: A compact, hand held carpet and upholstery extractor nozzle is provided having a pair of air turbine powered vertical axis rotary scrub brushes located adjacent the extractor nozzle. The turbine has at least one ambient air inlet and an outlet that communicates with a suction tube extending from the extractor nozzle. A compact gear reduction operatively connects the air turbine to the scrub brushes. A turbine outlet baffle is preferably provided that extends from an upstream edge of the turbine outlet, into the suction tube and over and beyond the turbine outlet to direct air, liquid and debris flowing through the suction tube over and beyond the turbine outlet opening. A downstream end of the baffle is open and suction openings pass through the baffle, for providing fluid communication between the suction tube and the turbine outlet opening. A raised floor is preferably located in the suction tube upstream of the baffle that directs the flow of air, liquid and debris in the suction tube substantially past the suction openings. A shoulder is preferably provided on each side of the baffle that extends generally longitudinally in the suction tube below the suction openings. The upstream ends of these shoulders curve upward until the shoulders are substantially flush with raised floor. With this construction, any drops of liquid adhering to the raised floor and traveling toward the baffle, will adhere to the shoulders and be directed below the suction openings.

Low NOx conditioner system for a microturbine power generating system

Abstract: A microturbine power generation system includes an electrical generator, a turbine and a compressor intermediate the generator and the turbine. The turbine, compressor and electrical generator are secured together by a tieshaft. The tieshaft is prestressed such that faces of the turbine, electrical generator and compressor maintain contact during high-speed, high-temperature operation of the system.

Next-Generation Integration Concepts for Air Separation Units and Gas Turbines

Abstract: The commercialization of Integrated Gasification Combined Cycle (IGCC) power has been aided by concepts involving the integration of a cryogenic air separation unit (ASU) with the gas turbine combined-cycle module. Other processes, such as coal-based ironmaking and combined power/industrial gas production facilities, can also benefit from the integration. It is known and now widely accepted that an ASU designed for elevated pressure service and optimally integrated with the gas turbine can increase overall IGCC power output, increase overall efficiency, and decrease the net cost of power generation when compared to nonintegrated facilities employing low-pressure ASUs. The specific gas turbine, gasification technology, NO x emission specification, and other site specific factors determine the optimal degree of compressed air and nitrogen stream integration. Continuing advancements in both air separation and gas turbine technologies offer new integration opportunities to improve performance and reduce costs. This paper reviews basic integration principles and describes next-generation concepts based on advanced high pressure ratio gas turbines, Humid Air Turbine (HAT) cycles and integration of compression heat and refrigeration sources from the ASU. Operability issues associated with integration are reviewed and control measures are described for the safe, efficient, and reliable operation of these facilities.

Gas turbine engine with exhaust expander and compressor

Abstract: Gas turbine engines working on an inverted Brayton cycle (IBC) which provides increased power output at a same fuel flow as is currently used in some other known cycles (e.g., air bottoming cycle) are described. In one embodiment, the engine includes a compressor coupled by a first shaft to a high pressure turbine. A combustor is located in the flow intermediate the compressor and high pressure turbine. A free wheeling power turbine is located downstream of the high pressure turbine, and the power turbine is coupled to a load by a second shaft. The flow from the power turbine is supplied, e.g., via ducts, to an axial turbine coupled to an axial compressor by a third shaft. A heat exchanger is located in the flow intermediate the axial turbine and axial compressor. In operation, the working fluid (e.g., air) is compressed by the compressor, and the compressed air is injected into the combustor which heats the air causing it to expand. The expanded air is forced through the high pressure turbine and the expanded air is supplied to the power turbine. Energy from the power turbine is transferred to the load via the second shaft. At least a portion of the air flow from the power turbine is supplied to the axial turbine which operates as an expander. The expanded air flow is supplied to an inlet of the heat exchanger, where at least a portion of the air flow is cooled from, for example, 600 degrees Fahrenheit to about 89 degrees Fahrenheit. The cooled and expanded air flow is supplied to the compressor, and air from the compressor is discharged into the atmosphere.

Air-Turbine with Self-Pitch-Controlled Blades for Wave Energy Conversion (Estimation of Performances in Periodically Oscillating Flow)

Abstract: In the development of an air-turbine with self-pitch-controlled blades for wave energy conversion, existence of hysteretic characteristics in a reciprocating flow has been examined. In order to clarify the validity of the analysis, a numerical simulation has been made by use of the experimental results obtained from a steady unidirectional flow condition. The comparison between the analysis and experiment has shown that the quasi-steady analysis is reasonable accurate for predicting the performance. The running and starting characteristics have also been investigated analytically taking into account the blade turning process during pitch.

Helicopter rotor tip jet

Abstract: A helicopter includes a rotor tip jet engine which combines ram compression and centrifugal compression to increase the thrust. A first flow of fuel is dispersed in the ram air and is carried into a combustion area of the engine. A separate flow of fuel is injected into the centrifugally compressed air before the fuel air mixture enters the combustion area. For helicopters and other applications, the ram jet engine combines ram air and a separate mass of compressed air which is directed into the combustion area for increased thrust. A regulator or control mechanism is also provided for regulating the quantity of compressed air which is added. The regulator or control mechanism may also be used to cut off or stop the addition of the separate mass of compressed air.

A laboratory evaluation of two brands of disposable air turbine handpiece.

Abstract: Objective: To report on the essential performance characteristics of two brands of disposable air turbine handpiece and on aspects of their safety and convenience for clinical use. Materials and Methods: Oralsafe and Feathertouch disposable handpieces were characterised using a variety of techniques in respect of the following: turbine rotor radius, equivalent orifice radius, stall torque coefficient, pressure effectiveness, power index, efficiency index, sound level and instrument retention force. Results: Free-running speed versus pressure curves for many of the disposable handpieces showed marked deviations from the expected smooth form. Considerable variation between examples of each type was found in most measured values. Evidence of eccentric rotors and high bearing friction was not found. Conclusions: Both brands of disposable handpiece had a number of problems: poor performance, vibration, excessive noise, variability of behaviour, poor bearings. Use of these devices is difficult to recommend. Improvement in design seems necessary

A New Gas Turbine Cycle for Economical Power Boosting

Abstract: A Moisture Air Turbine (MAT) cycle is proposed for improv- ing the characteristics of land based gas turbine by injecting atomized water at inlet to compressor. The power boosting mechanism of MAT is understood as composits of those of following existing systems: inlet air cool- ing system, inter-cooling and steam injection. Experiments using a 15MW class axial flow load compressor have been carried out to reveal that water evaporation in compressor could reduce compressor work in an efficient manner. Moreover, this technol- ogy has been demonstrated by means of 130MW class simple cycle gas turbine power plant to show that a small amount of water consumption is sufficient to increase power output. Very efficient evaporation could be achieved provided the size of water droplet is controlled properly. The amount of water con- sumption is much less than that of conventional inlet air cooling system with cooling tower for heat rejection. Incorporating water droplet evaporation profile into considera- tion, realistic cycle calculation model has been developed to predict power output with water injection. It has been shown that this technology is economically achiev- able. It should be stressed that contrary to well known evapora- tive cooler, MAT cycle could provide power output at a desired value within its capability regardless of ambient humidity condi- tion.

Vacuum cleaning device with a suction nozzle

Abstract: A vacuum cleaning device has a suction nozzle with a housing and an air guide chamber. The housing has an inflow opening. The suction nozzle further has a brush roller rotatably mounted adjacent to the inflow opening inside the housing. A bearing shaft is mounted within the housing. An air turbine is rotatably supported on the bearing shaft and driven in rotation by the suction air stream generated with the vacuum cleaning device. The bearing shaft has a longitudinal axis and the axis of rotation of the air turbine coincides with the longitudinal axis. The air turbine rotates at a different rpm than the bearing shaft. A planetary gear system is operatively connected between the air turbine and the bearing shaft. The planetary gear system is positioned at least partially within the air guide chamber within the vicinity of a first axial end face of the air turbine such that the air turbine at least partially axially overlaps the planetary gear system. A drive member is operatively connected to the planetary gear system for driving the brush roller.

Off-Design Flow Analysis and Performance Prediction of Axial Turbines

Abstract: Through-flow methods for calculations in axial flow turbines are limited by two facts: they cannot handle local flow reversal, and loss prediction at off-design operating conditions is not sufficiently accurate. An attempt to overcome these limitations is presented in this paper. The developed calculation method is based on the through-flow theory and the finite element solution procedure, but it also includes extensions and improvements. Consequently, the method may be used to predict the flow field and the turbine performance at the design load as well as for wide range of part loads. The code is able to calculate flow in axial turbines at subsonic and transonic conditions. The reliability of the method is verified by calculations for several gas and steam turbines. Results of flow calculation and performance prediction of 4-stage experimental air turbine and LP steam turbine are also presented herein. Low load operation with flow reversal in the hub region behind the last rotor blade row and loads, at which part of blading operates with power consumption, are especially analyzed. All numerical results are compared to the results of extensive experimental investigations. The correspondence, even for low loads, is very good.Copyright © 1997 by ASME

Breathing apparatus having electrical power supply arrangement with turbine-generator assembly

Abstract: An electrical power supply arrangement incorporates a turbine-generator ambly providing a self-contained non-battery electrical power source for supplying power to a breathing apparatus. The turbine-generator assembly is interposed in an air hose extending between first and second stage pressure regulators respectively connected to a pressurized air cylinder and to a cooling device of the breathing apparatus. The assembly includes an air turbine and an electrical generator disposed and coupled in tandem relationship to one another and enclosed in an elongated hollow housing. Pressurized air introduced into the turbine end of the housing expands across turbine blades and rotatably drives a central shaft of the turbine which, in turn, rotates a central rotor of the generator causing generation of electrical power in a stationary stator of the generator which surrounds the rotor. The electrical power can be accessed at a terminal block attached to the generator end of the housing for supplying power to operate the cooling device of the breathing apparatus.

Sucking tool for vacuum cleaner

Abstract: PROBLEM TO BE SOLVED: To provide a sucking tool for a vacuum cleaner which is highly durable and protects what is in contact with an agitator by forcedly stopping the revolution of the agitator or reducing the number of revolution when a sucking tool is positioned in the air. SOLUTION: Concerning this sucking tool for a vacuum cleaner, the flow-in angle of sucked air for driving an air turbine 6 is set to allow the air to flow in at a nearly parallel angle with respect to the blades of the air turbine 6 near a flow-in port 22 when the sucking tool is positioned in the air and the flowing angle is set to allow the flow-in air at a nearly vertical angle with respect to the blades of the air turbine 6 in a state where a part of the port 22 is formed to be covered by a floor surface when the sucking tool is positioned on the floor. Thereby, the agitator 14 revolves on the floor and automatically stops revolution at the time of lifting the sucking tool in the air. COPYRIGHT: (C)1998,JPO

Vacuum cleaning device with a suction nozzle

Abstract: A vacuum cleaning device has a suction nozzle with a housing and an air guide chamber. The housing has an inflow opening. The suction nozzle further has a brush roller rotatably mounted adjacent to the inflow opening inside the housing. A bearing shaft is mounted within the housing. An air turbine is rotatably supported on the bearing shaft and driven in rotation by the suction air stream generated with the vacuum cleaning device. The bearing shaft has a longitudinal axis and the axis of rotation of the air turbine coincides with the longitudinal axis. The air turbine rotates at a different rpm than the bearing shaft. A planetary gear system is operatively connected between the air turbine and the bearing shaft. The planetary gear system is positioned at least partially within the air guide chamber within the vicinity of a first axial end face of the air turbine such that the air turbine at least partially axially overlaps the planetary gear system. A drive member is operatively connected to the planetary gear system for driving the brush roller.

Cordless dental air turbine

Abstract: PROBLEM TO BE SOLVED: To provide a cordless dental air turbine of good controllability by permitting an air pressure generator to be freely removably mounted in a dental air turbine hand piece, so that an air tube and a cooling air tube as needed in conventional cases are not required. SOLUTION: A cordless dental air turbine has an air pressure generator 10 freely removably provided in a hand piece 1, and rotates a cutting tool 3 by supplying high-pressure air from the air pressure generator 10 to an air turbine 4 through a decompression valve 11 and a shutoff valve 13. While the shutoff valve 13 is opened and closed by a manual switch 14, compressed air in an air passage 5 is supplied into a water tank 15 through an air passage 16 to compress water in the water tank 15 to eject it toward the part of a tooth to be treated through water passages 17, 6.

Origins of Loss Within a Multistage Turbine Environment Under Conditions of Partial Admission

Abstract: A partially admitted first stage is routinely used in a wide variety of turbo-machines to match the turbine swallowing capacity to the cycle pressure ratio over a range of outputs. Such a configuration is often favoured for applications in which optimised part-load efficiency is a design requirement. Partial admission is achieved by dividing the stator row into discrete arcs, each of which can be separately supplied with fluid. This arrangement creates circumferential discontinuities and considerable unsteadiness in the flow field within the intra-stage gap, and this unsteadiness can propagate through several downstream rows of fully admitted blading.In the current work an unsteady, multi-stage, multi-passage, Navier-Stokes solver has been validated against experimental results from a multistage axial flow air turbine. Interstage traverses of static and total pressure are shown to agree well with the CFD predictions, and the measured and predicted partial admission loss is compared with published correlations. It is further shown that the operating point of downstream stages is influenced by the degree of partial admission in the first stage. Additionally, increased alternating blade bending stresses are predicted. These phenomena are not included in any published turbine design methods, and are discussed within the context of large output steam turbine optimisation.Copyright © 1997 by ASME

Hydraulic turbine generator and operation thereof

Abstract: PROBLEM TO BE SOLVED: To provide a hydraulic turbine generator with a thrust equalizing mechanism. SOLUTION: A sealless turbine generator TG mounted on a single shaft S comprises a radial turbine T and an induction turbine driven by the turbine T. The turbine T includes a thrust equalizing mechanism TEM which is operated by a portion of the working fluid furnished to the radial runner R of the turbine, and a thrust bearing which equalizes the generated thrust force by giving a minute movement in both axial directions to the elements provided on the thrust bearing and the shaft S. In a common housing CH, the shaft and the induction generator are isolated from the turbine elements other than the turbine runner. The whole assembly is contained in a submerged-type containment CV. The containment has a fluid entrance and a fluid exit, and receives a flow of inflowing hydraulic fluid with a persecuted hydraulic pressure and velocity or control the turbine speed.

Emergency power supply equipment

Abstract: PROBLEM TO BE SOLVED: To provide an emergency power supply equipment which makes only short delay at start and which can be maintained easily and can be constructed at a low cost. SOLUTION: At the time of power reception in this equipment, air is accumulated in an air tank 7 by a compressor 5 driven by the received power. At the time of power failure, an air turbine 12 is rotated by the high-pressure air accumulated in the air tank 7, and thereby a three-phase AC generator 13 is driven. In this case, an air turbine generator 13A is constructed of the three-phase AC generator 13 which is coupled to the air turbine 12, and an output of this three-phase AC generator 13 can be supplied to the power circuit side thereof as a single-phase AC power or a three-phase AC power through a single-phase AC generated power line 17 or a three-phase AC generated power line 14.

Wind power generation system

Abstract: PROBLEM TO BE SOLVED: To provide a simple and light-weight wind power generation system without setting up large facilities in an air space by disposing a plurality of windmills having air compressors in a matrix form and rotating an air turbine by compressed air obtained by each air compressor so as to run a generator SOLUTION: Windmills 1 having air compressors 2 are laid on a suspension wire 5 put on a main wire 4 provided between iron towers 3 and 3 in a matrix form Compressed air generated by each air compressor 2 is supplied to an air turbine 9 by a capillary tube 7 so as to drive this turbine Then, a generator is driven by power generated by the air turbine 9 and generated electricity is sent to a consuming part by an electricity sending line 13 For a windmill 1, a conventional type having a diameter of 1 to 10m is used and an area for actually receiving wind is increased by disposing a number of these mills in a matrix form A wire interval between upper and lower suspension wires 5 and 5 is held constant by a wire interval holding mechanism 6

Prediction of 3D-Unsteady Flow in an Air Turbine and a Transonic Compressor Including Blade Gap Flow and Blade Row Interaction

Abstract: This paper presents the results of three-dimensional unsteady Navier-Stokes simulations of the flow in a transonic compressor stage with inlet guide vanes and an axial flow air turbine stage with two identical stators for which detailed unsteady experimental data are available. Various unsteady flow phenomena are shown. The focus in the computations are stator/rotor interaction effects. Of special interest are their influences on the flow field downstream of the interface regions. The secondary flow effects are visualized via vector plots. The numerical results are compared with the experimental results. Although there is a good agreement in the major flow phenomena local deviations can be observed.Copyright © 1997 by ASME

Suction opening body of electric vacuum cleaner

Abstract: PROBLEM TO BE SOLVED: To provide the suction opening body of an electric vacuum cleaner in which an air turbine is efficiently rotated at the time of cleaning and the rotation of a rotating blade are speedily, reliably, and greatly reduced and halted in the state that a case body is lifted. SOLUTION: In a case body 15, a sucked air duct communicating with a communicating pipe 32 is constituted in a cleaning body chamber 18 rotation- freely housing a rotating blade 73, and a suction chamber 21 with the opening of a suction opening is formed. In the case body 15, an air intake opening different from the suction opening is formed to constitute a sucked air duct, and a turbine chamber 38 rotation-freely housing an air turbine 37 is provided. A pair of coils 60 are provided for the shaft body 41 of the air turbine 37 to constitute a rotating machine 63. A floor surface detecting means is provided at the lower surface of the case body 15. A short circuit occurs between the coils 60 and 60 at the time when a suction opening main body 11 is lifted from the floor surface, and electric power is generated at the rotating machine 63. By the action of dynamic braking generated by the generated current, the rotation is braked and speedily halted without noise.

Suction opening casing for vacuum cleaner

Abstract: PROBLEM TO BE SOLVED: To efficiently rotate an air turbine at the time of cleaning and to easily stop the rotary blade at other times. SOLUTION: In a housing 15, a turbine chamber 33 is dividedly formed that communicates with the outside through an intake port and that axially supports an air turbine 46 freely rotatably. The downstream side of the intake of the turbine chamber 33 is communicated with an air passage chamber 21 communicative with a suction chamber 20 in which an intake port 24 is opened. In the lower part of a housing 12, a leak port 26 is formed which is larger in both opening area and intake capacity than the intake port communicating with the air passage chamber 21 and with the downstream side of the intake of an air turbine 46. A projection 27 bulging downward like a wall is provided at the opening edge of the leak port 26, while a pair of elastic pieces 28 are attached to the front and back opening edges of the leak port 26. The traveling of a suction opening casing 11 elastically transforms the elastic pieces 28 to the side opposite to the travelling direction, to block the leak port 26, so that the air turbine is rotated by the intake air flow from the intake port. When lifting the suction opening casing 11, an air intake is actuated from the leak port 26 to stop the air turbine 46.

A Mechanical Start System for U. S. Navy Destroyer Generator Sets

Abstract: A mechanical start system has been developed to start the Ship’s Service Gas Turbine Generators (SSGTG) on board U.S. naval destroyers. The current starting system uses either stored high pressure air or bleed air from another running turbine. The U.S. Navy has reviewed the high pressure air system and found it to be a costly system for both ship construction and maintenance. As a result, the Navy is requiring an alternative starting method that will replace high pressure air. It should be noted that any alternative that introduces compressed air to start the SSGTG depends on the start air regulating assembly and the pneumatic starter.The Redundant Independent Mechanical Start System (RIMSS) consists of an Allison Model 250 turboshaft engine mounted above the SSGTG main reduction gearbox. The turboshaft power take off is connected to the pinion shaft of the reduction gearbox by means of a parallel shaft auxiliary transfer gearbox. The transfer gearbox connection to the reduction gearbox replaces the pneumatic starter adapter pad but provides a means to also connect the pneumatic starter. As a result, the pinion shaft can be driven either pneumatically by the air turbine or mechanically by the Model 250 engine. This provides an alternative starting mode which is totally independent of the present means of starting. This will increase the reliability and availability of the SSGTG since it can still be started even if the pressure regulator or the pneumatic starter is not functional. This system has undergone testing at the Naval Surface Warfare Center Carderock Division facility in Philadelphia.Copyright © 1997 by ASME