Abstract: A control method for a centrifugal compressor and an air conditioning system. The control method for the centrifugal compressor includes: S100, when an inlet opening of the centrifugal compressor is below a first preset value, shutting down a drive motor of the centrifugal compressor; or S200, when the inlet opening of the centrifugal compressor is not below the first preset value, performing the following operations in a preset order: decreasing the inlet opening of the centrifugal compressor, and increasing a rotate speed of the centrifugal compressor.

Abstract: A high torque dual speed turbine rotor for a lightweight hand held tool for grinding and polishing or for use with a spindle mounted pneumatic machine. The high torque dual speed turbine rotor includes a two-piece shaft with flow control screw disposed within the shaft. The shaft includes a first set of hollow openings, at a first position from one end of the shaft, in fluid communications with a first annular chamber of a rotor. There is also a second set of hollow opening, at a second position from the one end of the shaft, in fluid communications with a second annular chamber of the rotor. The flow control screw moves inside a threaded axial bore of the shaft from an open position inside the axial bore to the closed position corresponding to the second set of hollow openings.

Abstract: An aeronautical propulsion device including a fan and a plurality of variable guide vanes is provided. The fan includes a plurality of fan blades for providing a flow of air and the plurality of variable guide vanes are configured for directing air to or from the fan in a desired direction. Each of the plurality of guide vanes defines an inner end along the radial direction and is attached to a housing of the portion device at the inner end in a rotatable manner. The propulsion device further includes a pitch change mechanism positioned in the housing and mechanically coupled to at least one of the plurality of guide vanes for changing a pitch of the at least one of the plurality of guide vanes.

Abstract: A vehicle engine system includes an internal combustion engine, an air induction system configured to supply intake air to the internal combustion engine, and an evaporative emissions control (EVAP) system is configured to selectively supply purge fuel vapor to the EHC for subsequent combustion and rapid heating to a predetermined catalyst light-off temperature. The system additionally includes a booster configured to charge the intake air, and an engine bypass conduit fluidly coupled between the booster and the exhaust aftertreatment system. When the internal combustion engine is off, the booster selectively supplies a flow of intake air through the engine bypass conduit to the exhaust aftertreatment system. The flow of intake air draws purge fuel vapor from the EVAP system into the exhaust aftertreatment system.

Abstract: An air-inlet duct includes an outer wall, an inner wall, and a splitter. The splitter cooperates with the outer wall to establish a particle separator which separates particles entrained in an inlet flow moving through the air-inlet duct to provide a clean flow of air to a compressor section of a gas turbine engine.

Abstract: A system for detecting a position of a dual solenoid device includes device configured to move between first and second positions, and a controller. The controller has first and second monitoring circuits in operable communication with first and second channels, respectively. The first and second channels are in operable communication with first and second solenoids, respectively. Each solenoid is configured to selectively operate as an active solenoid to move the device when the solenoid and its respective channel are in an active mode, and as a passive solenoid when the solenoid and its respective channel are in a passive mode to passively move with the active solenoid. Each of the monitoring circuits is configured to determine a position of the device when the channel the monitoring circuit is associated with is operating in the passive mode by monitoring an electrical parameter of the passive solenoid associated with that channel.

Abstract: A fan device for high torque output has two base plates, multiple fans, and a spindle. The base plates are mounted parallel to each other. The fans are mounted between the base plates, and each fan has an inner side, an outer side, and an inflection point. The spindle is connected with one of the base plates and is located at a middle position of the base plate. A connecting line that connects the inflection point and the spindle is out of an area defined between a connecting line that connects the spindle and the inner side and a connecting line that connects the spindle and the outer side when the inflection point, the inner side, and the outer side are located at the same horizontal plane. Therefore, each fan has a large frontal area to be pushed by fluid.

Abstract: Systems and programs for controlling thrust in a turbine by adjusting the clearance between a packing seal and a rotating component are disclosed. In one embodiment, a system includes a controller configured to move a packing seal to a selected clearance position in response to a thrust pressure exceeding a target pressure, and a sensor coupled to the controller and configured to detect the thrust pressure.

Abstract: A system for controlling at least two variable geometry apparatuses of a gas turbine engine that includes at least a first body and a second body, the first apparatus including a stator blade stage with a variable setting angle of a compressor of the first body capable of switching between a closed position in an idle mode and an open position in a high-speed mode, and the second apparatus including at least one discharge valve of a compressor of the second body capable of switching between an open position in an idle mode and a closed position in a high-speed mode. The system further includes an actuator for actuating the two apparatuses.

Abstract: A pressure-balancing device for balancing pressure in at least one bearing enclosure of a turbojet, the enclosure including a mechanism feeding the bearing with lubricating liquid, an air intake, at least one sealing system placed between the stator and the rotor in front of and/or behind the bearing, a recovery mechanism recovering the lubricating liquid, and a removal mechanism removing the mixture of air and of traces of lubricating liquid towards a venting circuit. Downstream from the bearing enclosure and in the venting circuit, the balancing device includes a regulator system regulating the air removal flow rate, thereby enabling the flow rate to be variable as a function of the speed of the engine, to remain non-zero, and, at high speeds, to be lower than when the regulator system is not included.

Abstract: A system for controlling at least two sets of variable geometry equipment of a gas turbine engine including at least one first body and a second body, the first set of equipment being a stage of variable stator vanes of a compressor of the first body moving between a closed position during idling and an open position at high speed, and the second set of equipment being at least one bleed valve of a compressor of the second body moving between an open position during idling and a closed position at high speed. An actuator actuates the two sets of equipment.

Abstract: A system for controlling at least two sets of variable geometry equipment of a turbine engine. The turbine engine includes at least one first body and a second body, the first set of equipment being a stage of variable stator vanes of a compressor of the first body moving between a closed position during idling and an open position at high speed, and the second set of equipment being at least one bleed valve of a compressor of the second body moving between an open position during idling and a closed position at high speed. The actuator drives the second set of equipment by an actuating part that is actuated over part of the course of the actuator and idle on an abutment over the rest of the course, and by a sliding joining element providing a backlash in the actuation of the second set of equipment.

Abstract: A method for increasing the operational flexibility of a turbomachine during a shutdown phase is provided. The turbomachine may include a first section, a second section, and a rotor disposed within the first section and the second section. The method may determine an allowable range of a physical parameter associated with the first section and/or the second section. The method may modulate a first valve and/or a second valve to allow steam flow into the first section and the second section respectively, wherein the modulation is based on the allowable range of the physical parameter. In addition, the physical parameter allows the method to independently apportion steam flow between the first section and the second section of the turbomachine, during the shutdown phase.

Abstract: Methods, apparatus, and products are disclosed for improving the airflow exiting a blower that has one or more adjustable guide vanes that are affixed to the blower at one or more pivot points located in an outlet of the blower that include: determining a rotational speed of an impeller in the blower and adjusting a position of at least one of the adjustable guide vanes in dependence upon the rotational speed of the impeller.

Abstract: A control system for controlling at least two variable-geometry devices of a turbomachine, and a turbomachine including such a control system, the system including an actuator that actuates both devices; one of the devices including at least one stage of variable-pitch stator vanes, and the other device being an air-bleed valve for a turbomachine body. The system is configured to control progression opening of the vane stage and progressive closing of the air-bleed valve as an actuation parameter of the actuator increases. As a result, the control system serves advantageously to control two devices using a single control system.

Abstract: A control method and apparatus for critical rotational speed avoidance in a compressor-expander set in a gas refrigeration system. By varying an opening of an antisurge or recycle valve, a shaft power used by the compressor in the compressor-expander set may be varied, thereby varying the rotational speed of the compressor-expander set to move it away from its critical speed zone. Additionally, a feedforward signal may be provided by a compressor-expander set control system to cause an antisurge valve for a recycle compressor to open upon a trip or shutdown of one compressor-expander set.

Abstract: A system for controlling at least two variable-geometry equipments of a gas turbine engine is disclosed. The engine includes at least a first core rotating at a first speed and a second core rotating at a second speed. The first equipment includes at least one variable-pitch stator blade of a compressor of the first core and the second equipment includes at least one air bleed valve of a compressor of the second engine core moving between an open position at idle speed and a closed position at high speed. The system includes an actuator which actuates both equipments.

Abstract: A system for controlling at least two variable-geometry equipments of a gas turbine engine is disclosed. The engine includes at least a first core rotating at a first speed and a second core rotating at a second speed. The first equipment includes at least one variable-pitch stator blade of a compressor of the first core and the second equipment includes at least one air bleed valve of a compressor of the second engine core moving between an open position at idle speed and a closed position at high speed. The system includes an actuator which actuates both equipments.

Abstract: A system for controlling at least two variable-geometry equipments of a turbomachine, in which the first equipment is a variable pitch stator blade stage of a compressor of a first core moving between a closed position at idle speed and an open position at high speed, and the second equipment is at least one bleed valve of a compressor of a second core moving between an open position at idle speed and a closed position at high speed, is disclosed. The actuator operates over a portion of its travel a first branch of an angle transmission member which actuates the first equipment and leaves this branch at rest on an abutment over the rest of its travel. The actuator operates the second equipment via a sliding junction member arranging a free travel in the actuation of said second equipment.

Abstract: An air regulator comprises a housing, a shaft, a first air regulation member and an elastic ring. The shaft is rotationally fixed within the housing. The first air regulation member is coaxially coupled to the shaft and has a plurality of first air flow apertures positioned radially about the shaft. The elastic ring is configured and positioned to centrifugally deform and increasingly block the first air flow apertures.

Abstract: A turboexpander-compressor system includes an expander configured to expand an incoming gas, a first set of moveable inlet guide vanes configured to control a pressure of the incoming gas, a compressor configured to compress a gas received from the expander, a shaft configured to support and rotate an expander impeller and a compressor impeller, a second set of moveable inlet guide vanes attached to the compressor and configured to control a pressure of the gas input into the compressor, and a controller configured to acquire information about a rotating speed of the shaft, a pressure and a temperature of the incoming gas, a pressure and a temperature of the gas output from the expander, and to control the second set of moveable inlet guide vanes to maximize a ratio between the rotating speed of the shaft and a drop of an enthalpy across the expander, in off-design conditions.

Abstract: Methods, apparatus, and products are disclosed for improving the airflow exiting a blower that has one or more adjustable guide vanes that are affixed to the blower at one or more pivot points located in an outlet of the blower that include: determining a rotational speed of an impeller in the blower and adjusting a position of at least one of the adjustable guide vanes in dependence upon the rotational speed of the impeller.

Abstract: A silencer in a flow duct (10) comprises at least one plate-shaped element (12) which extends essentially parallel to the throughflow direction (16) of the flow duct. Integrated in the plate-shaped element (12), preferably in the downstream region, are means (13, 14) for feeding and for spraying a liquid (15) into the throughflow of the flow duct. The spraying means are preferably arranged in such a way that the liquid (15) is sprayed at an angle of at least 30° to the throughflow (16). The silencer according to the invention is used, for example, in the intake duct of a gas turboset.

Abstract: A system for controlling a centrifugal gas compressor (108) in an HVAC, refrigeration or liquid chiller system (100) in which flow of gas through the compressor is automatically controlled to maintain desired parameters within predetermined ranges so as to prevent stall and surge conditions within the system. A variable geometry diffuser (119) in the compressor controls the refrigerant gas flow at the discharge of the compressor impeller wheel (201). This arrangement reduces mass flow, decrease/eliminate flow-reducing stall, and increases the operating efficiency of the compressor at partial load conditions. The variable geometry diffuser control in combination with a variable speed drive (VSD) (120) increases the efficiency of the compressor at partial system loads, and eliminates the need for pre-rotation vanes at the inlet of the centrifugal compressor.

Abstract: To provide a method of controlling a turbine equipment and a turbine equipment capable of carrying out a starting operation of controlling a load applied to a speed reducing portion while complying with a restriction imposed on an apparatus provided at a turbine equipment. The invention is characterized in including a speed accelerating step (S1) of increasing a revolution number by driving to rotate a compressing portion and a turbine portion by a motor by way of a speed reducing portion, a load detecting step (S2) of detecting a load applied to the speed reducing portion by a load detecting portion, and a bypass flow rate controlling step (S3) of increasing a flow rate of a working fluid bypassed from a delivery side to a suction side of the compressing portion when an absolute value of the detected load is equal to or smaller than an absolute value of a predetermined value and reducing the flow rate of the bypassed working fluid when equal to or larger than the absolute value of the predetermined value.

Abstract: A shroud for vertical axis wind turbines. The shroud contains vanes that direct airflow to the turbine blades to increase efficiency. The vanes in the shroud further provide a means to close entirely the turbine from adverse weather conditions. The vanes are operated utilizing electrical feedback from the rotational speed of the turbine.

Abstract: A system for controlling at least two variable-geometry equipments (10, 110) of a turbomachine, the first equipment (10) being a variable pitch stator blade stage of a compressor of a first core moving between a closed position at idle speed and an open position at high speed, the second equipment (110) being at least one bleed valve of a compressor of a second core moving between an open position at idle speed and a closed position at high speed. The actuator operates over a portion of its travel a first branch (34, 341) of an angle transmission member (26) which actuates the first equipment (10) and leaves this branch at rest on an abutment (64) over the rest of its travel; moreover it operates the second equipment (110) via a sliding junction member (120) arranging a free travel in the actuation of said second equipment.

Abstract: A control method and apparatus for startup of turbocompressors to avoid overpowering a driver of the turbocompressor. In a first embodiment, the control system monitors input signals from transmitters of various control inputs. When the input signals exceed threshold values, the control system begins to close the antisurge valve. In a second embodiment, the antisurge valve begins to close after a predetermined time measured from the time startup is initiated. In both embodiments, the antisurge valve continues to ramp closed until the compressor has reached its operating zone, or until the compressor's operating point reaches a surge control line, at which point the antisurge valve is manipulated to keep the compressor from surging.

Abstract: A control method and apparatus for critical rotational speed avoidance in a compressor-expander set in a gas refrigeration system. By varying an opening of an antisurge or recycle valve, a shaft power used by the compressor in the compressor-expander set may be varied, thereby varying the rotational speed of the compressor-expander set to move it away from its critical speed zone. Additionally, a feedforward signal may be provided by a compressor-expander set control system to cause an antisurge valve for a recycle compressor to open upon a trip or shutdown of one compressor-expander set.

Abstract: A self-opened type valve is opened by motor torque of an electric motor. Therefore, a diaphragm is not necessary for opening the valve, and downsizing of a valve drive apparatus for opening the valve is possible. Since the valve is assembled to the motor shaft of the electric air pump via a motion-direction conversion mechanism, an opening action of the valve can start in a short time after a rotational action of the impeller of the electric air pump starts, so that control responsiveness is improved. At a rotation stop of the impeller of the electric air pump, the valve can be maintained in a fully closed condition by an urging force of the coil spring, thereby preventing exhaust gases or condensed water from entering into an inside of the electric air pump.

Abstract: An air driven tool for use in a machining center, the air driven tool including an adjustable speed regulator and a turbine. The turbine is driven by pressurized air directed thereto. The turbine is rotatable about an axis. A flow of the air is regulated by the adjustable speed regulator. The adjustable speed regulator includes a biasing member, an inclined annular surface, a regulator plate and a plurality of moveable bearings. The inclined annular surface has an angle relative to the axis. The plurality of movable bearings are positioned between the inclined annular surface and the regulator plate. The biasing member biases the inclined annular surface and/or the regulator plate toward each other.

Abstract: The present invention includes an inflow quantity regulating means 5 for regulating the inflow quantity of a fuel gas to a compressor 1; a recycle valve 7 for returning the fuel gas discharged from the compressor 1 to the inlet side of the compressor 1; and a control means which sets a control operating value for operating the compressor 1 at a predetermined operation point, and controls the inflow quantity regulating means 5 and the recycle valve 7 based on the control operating value. The control means has a first control signal generating means 27 which generates a signal increasing with an increase in the operating value as a control signal for the inflow quantity regulating means 5 when the control operating value is a predetermined value or larger and a second control signal generating means 29 which generates a signal decreasing with an increase in the operating value as a control signal for the recycle valve 7 when the control operating value is smaller than the predetermined value.

Abstract: A limit switch 6 is placed on an end portion of the trip rod 4, which converts the mechanical deviation of the trip rod 4 into an electrical signal. The electrical signal from the limit switch 6 is transmitted to quick acting solenoid valves placed in a drive unit for a steam valve via a sequence circuit device, and then the steam valve is closed. Accordingly, an equipment structure can be simplified and reliability can be improved as compared to conventional arts.

Abstract: A pneumatic high speed motor includes a stator housing, a rotor journalled in the stator housing, and a pressure air inlet passage. A speed governor for the motor includes a valve element that is shiftable between an open position and a closed position for controlling pressure air flow through the pressure air inlet passage, and a spring which continuously biases the valve element toward open position. An air compressor is driven by the rotor to deliver an output pressure, which is responsive to a speed of the rotor, to an activating surface of the valve element. The activating surface of the valve element is acted upon by the output pressure of the air compressor to shift the valve element toward the closed position against the bias force of the spring at rotor speed levels exceeding a desired operating speed level.

Abstract: The present invention is a method of minimizing steam boiler pressure changes or turbine power changes during turbine control valve operational safety test stroking. The method of the present invention uses control valve positions as feedback into a compensation algorithm to minimize flow disturbance caused by the closing and reopening of a turbine control valve during periodic operational testing. By maintaining the total mass flow through several parallel turbine inlet control valves constant, the steam generator pressure is maintained constant, and the inlet pressure regulator is unaffected during inlet control valve testing. Maintaining the total mass flow through several parallel turbine inlet control valves constant also minimizes turbine power changes during inlet control valve testing. In addition, the monitoring of additional process parameters is not needed.

Abstract: The present invention provides a speed governor (5) suitable for use in a fluid driven down-hole tool (3). The speed governor comprises an actuator (7) operatively coupled to a motive fluid flow control valve (6). The actuator is and arranged so as to be activatable, directly or indirectly, in response to the running speed of the tool (3), for opening of the control valve (6) with increasing rotational speed of the motor (3) above a predetermined speed limit thereby to limit the rotational speed of the downhole tool (3).

Abstract: Steam turbine control systems often incorporate electromechanical pilot-valve actuator assemblies to regulate hydraulically-driven actuator pistons that modulate steam valves, thereby controlling turbine speed. The general operation and quick-response requirements of these pilot-valve actuator assemblies can suffer from shortcomings (such as, excessive friction, contaminated oil, and defective electromagnetic components) that degrade the control system's overall performance. For these reasons, this disclosure relates to a method for overcoming insufficient, pilot-valve actuator response by using an integrated control system dedicated to these electromechanical assemblies. Pilot-valve actuators can be equipped with a single coil or multiple coils (usually a primary and a secondary). In a dual-coil configuration, the primary is energized according to an output of a PID controller, whereas the secondary coil is regulated by a separate control element.

Abstract: A pump turbine includes a runner connected to a generator motor, a water discharge controller for adjusting the quantity of water passing through the runner and a governor for detecting a rotational speed of the runner and controlling the water discharge controller to get a predetermined rotational speed of the runner. Upon a load rejection which shuts off the generator motor from an electric power system, the governor is controlled to make a target speed value of the runner after a load rejection higher than a target speed value before the load rejection. The target speed value is a reference speed to be compared with actual speed so that the governor determines when or how to open or close a water discharge controller in response to a balance between the two speeds.

Abstract: A turbine installation comprising a turbine in combination with an electrical closed-loop control system. The turbine is disposed in a flow of water for producing electrical energy. The turbine includes a hollow hub and a plurality of runner blades pivotally connected to a hollow hub. Each blade comprises a hydrofoil being bounded by an inner surface and a distal outer surface, a leading edge and a trailing edge separated by a water directing surface. The blades are adjustable in pitch from a maximum pitch position in which an inner portion of the water directing surface extends substantially in a direction of the water flow, to a minimum pitch position in which an outer portion of the water directing surface is substantially perpendicular to the water flow. The hollow hub has spaced apart inner and outer surfaces and a hub longitudinal axis. Each blade is pivotally connected to the hub about a rotational axis.

Abstract: Maintenance requirements on a variable pitch propeller control system are minimized by eliminating the need for mechanical elements, such as a flyweight, mechanism in a secondary control for the variable pitch propeller. The system includes a secondary control (40) operating a pitch change mechanism (24) in response to the existence of at least one undesirable propeller condition and includes a target (34), (38) along with a target pickup (32), (36) for sensing the target (34), (38) and providing information to a function generator (76) which in turn provides information to a logic device (78), (80), (82), (84), (86), (88), (94) which in turn is connected to the pitch change mechanism (24) for operating the same.

Abstract: A turbine, adaptable to improve the survivability of fish present in water flowing therethrough, includes a hub and associated runner blades. Each blade comprises an inner edge and a distal outer edge, a leading edge and a trailing edge separated by a water directing surface. Each blade is rotatable relative to the hub about a blade rotational axis. The turbine is provided with a gap shielding device designed to shield a gap formed between the hub and the blade inner edge as the blade is rotated about its axis. The gap shielding device may comprise a plurality of independently biased pins, a plurality of fluid jets, a plurality of flexible members, a fluid-filled boot, and combinations thereof.

Abstract: A method of testing an actuation system for positioning an actuator, the actuation system including a primary electronic system, a secondary hydro-mechanical system is disclosed. The method includes the steps of measuring the actual position of the actuation device as set by the primary electronic system; measuring the system inputs and computing an ideal actuator position based thereon; determining the difference between the actual actuator position and the ideal position. The difference is then compared to a first threshold value which represents a disturbance beyond which the system cannot safely operate. Control is transferred from the primary control to the secondary control if the difference exceeds the first threshold. If the difference is less than the first threshold, the difference is compared to a second threshold value which represents an operating condition that can be tolerated for a period of time.

Abstract: A low drag ducted ram air turbine generator and cooling system is provided. The ducted ram air turbine generator and cooling system has reduced drag while extracting dynamic energy from the air stream during the complete range of intended flight operating regimes. A centerbody/valve tube having an aerodynamically shaped nose is slidably received in a fairing and primary structure to provide a variable inlet area. An internal nozzle control mechanism attached to the valve tube positions nozzle control doors to provide variable area nozzles directing air flow to the turbine stator and rotor blades to maintain optimum generator efficiency. An alternate embodiment includes an annular internal nozzle having interleaved panels to modulate the air flow to the turbine.

Abstract: In a preferred embodiment, the invention relates to a steam turbine having a speed-loop droop governor with two load-frequency error gains (droops). The first gain (fast change) may be a conventional high gain that is used for power loads that have a constant frequency. When using only the first gain, the high rate of the first gain causes the droop governor to shut off steam to the turbine if the speed of the turbine drifts above a narrow speed range centered on the rated speed set-point. The second gain (slow change) is a low gain that causes the droop governor to tolerate a wide range of turbine speeds about the rated speed set-point.

Abstract: A governor mechanism is mounted for rotation with a drive shaft about an axis, has one or more reaction nozzles for imparting rotational movement to the drive shaft, and one or more valve portions supported for radially directed sliding movement between first and second radially spaced positions for purposes of controlling flow of pressurized fluid to the nozzles and thus the rotational speed of the drive shaft. The valve portions are formed integrally with a ring-shaped mounting portion fabricated from resiliently deformable material. In alternative constructions, similar governor mechanisms are co-axially mounted with vane motors by a common drive shaft and the mechanisms employed to control flow of pressurized fluid to the vane motor.

Abstract: An upper reservoir-side conduit or a lower reservoir-side conduit is branched in the vicinity of pump-turbine ends and at least a first pump-turbine out of a plurality of pump-turbines which share the conduit portions located farther than the branch points with the other pump-turbine or pump-turbines is provided with a rotational speed increase detector. When it is detected that the rotational speed of the first pump-turbine has exceeded a second predetermined value higher than a rated speed, a command is issued also to at least one of the other pump-turbines to limit the guide vane closing speed in that pump-turbine to a speed approximately equal to or lower than the speed after the shift to a slow closing of the guide vanes.

Abstract: A control system for controlling the rotational speed of a turbine for producing electrical power and a method for controlling the rotational speed of a turbine during load shedding include a control structure. The control structure can be connected to an actuator, which is used to control the rotational speed, and the control structure is used to control the rotational speed of the turbine during idling and/or insular operation of the turbine. An error signal which is dependent on a difference between a setpoint value and an actual value of the rotational speed, can be supplied to the control structure. During load shedding, the control structure supplies a closing signal to the actuator as a function of the error signal. The control structure combines the function of controlling the rotational speed during idling and/or insular operation of the turbine with the function of avoiding rapid shutdown of the turbine when load shedding occurs.

Abstract: An upper reservoir-side conduit or a lower reservoir-side conduit is branched in the vicinity of pump-turbine ends and at least a first pump-turbine out of a plurality of pump-turbines which share the conduit portions located farther than the branch points with the other pump-turbine or pump-turbines is provided with a rotational speed increase detector. When it is detected that the rotational speed of the first pump-turbine has exceeded a second predetermined value higher than a rated speed, a command is issued also to at least one of the other pump-turbines to limit the guide vane closing speed in that pump-turbine to a speed approximately equal to or lower than the speed after the shift to a slow closing of the guide vanes.

Abstract: A stator apparatus for mounting upstream of an intake to a rotating machine which blows pressurized air, or other media, from discharge orifices at a pressure and velocity to minimize velocity defects or turbulence in the wake of the stator prior to the plane of rotation of a rotating member of the machine. The rotating member then encounters a substantially uniform velocity medium at the plane of incidence, which substantially reduces uneven loading on the rotating member, thereby reducing noise and reducing high-cycle failure of that rotating element. The distribution and size of the orifices is determinable by placing the stator apparatus in a wind tunnel, or on the intake of a apparatus simulating the intake of the rotating machine, measuring the turbulence or velocity defects in the stator wake, and modifying the distribution and size of the orifices until the turbulence is minimized.

Abstract: A compressor is disclosed having a characteristic modifier, such as air injection, adapted to modify an operating characteristic of the compressor in order to reduce the bandwidth and rate limit requirements of the compressor. The compressor includes an actuator, such as a bleed valve, whose bandwidth and rate limit parameters meet the corresponding reduced requirements of the compressor. The actuator is adapted to stabilize the compressor with respect to a likely condition in the compressor which would tend to make the compressor operate in a less stable manner. This makes it possible to stabilize the compressor using a more readily available actuator having lower bandwidth and rate limit parameters.