Abstract: A radial-flow pump (1), and especially a coolant pump for an internal combustion engine, comprising an impeller (2) provided with vanes (5) and a directing device (4) including at least one temperature- and/or speed-sensitive element for temperature-dependent control of the coolant flow, where at least one impeller vane (5) and/or the directing device (4) is configured as a speed-sensitive element. In order to increase efficiency, the proposal is put forward that the impeller vanes (5) should be elastically deformable by Coriolis forces of the coolant flow, the discharge angles (&agr;), which are preferably defined between impeller vanes (5) and impeller tangential planes (&egr;), decreasing with an increase in speed.

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 method for determining whether a centrifugal pump is degraded as operating outside of acceptable operating limits and includes the steps of determining a motor torque/TDH relationship over a range of speeds for minimum and maximum flow rates and at least at two other intermediate flow rates, sensing and measuring at least another pump value selected from a differential pressure across the pump, a pump discharge pressure or pump flow, to provide an output pump value and comparing said value with said determined relationship values to provide an indication as to whether said pump has degraded.

Abstract: Methods and apparatus for controlling power supplied to vapor jet vacuum pumps are provided. A vapor jet vacuum pumping system includes a vapor jet pump having an inlet port, an exhaust port, a jet assembly and an boiler, the boiler including a heater, and a power controller for automatically controlling power supplied to the heater in response to at least one control parameter. The power may be controlled in response to a programmed sequence, to a sensed pressure in a process chamber, to control signals from a process control system, or to combinations of these control parameters.

Abstract: Wind power installations using more modern technology have long been known. Such wind power installations have rotors comprising at least one or more rotor blades. The rotors and accordingly the rotor blades carried thereby of wind power installations are subjected to a particular degree to the ambient environmental influences such as for example rain, snow, hail or also insects. In particular the leading edges of the rotor blades are heavily loaded in that respect. In that situation it can happen that the rotor blades and in particular the leading edges thereof, after some time, suffer from (mechanical) damage, for which cost-intensive repair is necessary, especially as a crane is frequently required for that purpose and the entire wind power installation is also stopped for a prolonged period due to the repair and under some circumstances even individual rotor blades have to be transported away to the repair location.

Abstract: A method and apparatus for detecting the occurrence of surge or incipient surge in a centrifugal compressor is supplied. The centrifugal compressor has an inlet passage, an inlet passage wall and an impeller. When flowing a fluid through the centrifugal compressor thereby establishing a fluid flow in the inlet passage, the fluid flow is measured in the inlet passage proximate the inlet passage wall and proximate the impeller. The measurements may include detecting a reverse in the fluid flow direction, measuring a tangential component to the fluid flow, measuring a substantial decrease in the axial fluid flow, and/or measuring the fluid temperature. Fluid flow in the compressor can then be modified or controlled to prevent surge.

Abstract: To prevent surge of a turbocompressor (K), a anti-surge valve (27) provided at the compressor outlet is controlled by a controller (R). The input signal for the controller (R) is generated as a function of the instantaneous flow and the end pressure of the compressor (K) such that the controller responds more slowly to working point shifts in the direction of the surge limit line and more rapidly to working point shifts in the opposite direction. This is achieved by arranging an asymmetric time element or a gradient sensor in the circuit generating the input signal for the controller (R).

Abstract: To protect a turbocompressor (3) with a downstream process from operation in the unstable working range, a machine controller is used, which optionally contains—besides a surge limit controller (15)—an intake pressure controller (11), an end pressure controller (20) and a bypass controller (9). A control matrix is determined from the position of a control unit (fuel gas control valve 6) determining the flow to the process, optionally taking into account additional influencing variables such as the compressor intake pressure and the compressor discharge pressure.

Abstract: In a compressor system, in which plural numbers of compressors are connected in parallel with, wherein flow rate of all the compressor main bodies driven under load operating condition is decreased down by closing each of the inlet guide vanes thereof, when a load of the compressor goes down, and then the compressor rushing into surge at the earliest is brought into unload operating condition. Thereafter, the flow rates of the compressors other than that brought into the un-load operating conditions are increased up, thereby conducting the operation of the compressor depending upon the load.

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: An apparatus for monitoring the health of a compressor including at least one sensor operatively coupled to measure the dynamic pressure of gases flowing through the compressor, a processing system coupled to at least one sensor, the processor system recording and processing the measurements made by at least one sensor. The apparatus further includes a comparator that compares the sensor measurements with predetermined baseline values, and a real-time controller coupled to the comparator, the controller initiating corrective actions to prevent a compressor surge if the sensor measurements deviate from the predetermined baseline values.

Abstract: Accurate and effective antisurge control for turbocompressor stages is augmented by measuring the flow rate of fluid entering or leaving the stage of compression. On the other hand, turbocompressors with sidestreams, such as ethylene, propylene, and propane refrigeration compressors, pose unique antisurge control challenges; in particular, measurements for the flow rate entering (or leaving) the compressors' middle stages are not available in most cases. Furthermore, the methods used to cope with this lack of flow measurements are prone to introducing errors and producing false transients, as well as being cumbersome and difficult to implement. For these reasons, this disclosure relates to a method for protecting turbocompressors with sidestreams from the damaging effects of surge.

Abstract: Compensating for the complex changing shape and location of a turbocompressor's surge limit line can be difficult and imprecise when using antisurge controllers that do not incorporate sufficient capability. Based upon various operating conditions, surge limit line changes can be attributed to a number of process variables. These effects are particularly relevant to multistage centrifgal and axial turbocompressors operating with variable rotational speed and equipped with adjustable inlet or diffuser guide vanes, or both. This invention relates to an innovative method of antisurge control in which the function of those process variables (comprising the turbocompressor operating condition parameters) is used to calculate distances to the surge reference line. The function is formed as a superposition of the functions of lesser numbers of variables.

Abstract: To provide a protective device for a turbo molecular pump and a method of protecting a turbo molecular pump that may cope with abnormal phenomenon according to a kind thereof when the abnormal phenomenon occurs. A kind of abnormal phenomenon is inferred from a change rate in rpm of a rotor when the abnormal phenomenon such as an injection of atmospheric air into an intake port is generated in the turbo molecular pump or the like and a magnitude of the damage imparted to the turbo molecular pump by the abnormal phenomenon is inferred from the rpm of the rotor upon the generation of the abnormal phenomenon. Furthermore, a value weighted to the magnitude of the damage is caused to correspond to and the value is accumulated whenever the abnormal phenomenon occurs in the turbo molecular pump. When the accumulated value reaches a certain value, the protective function is effected so that the turbo molecular pump is stopped to disable its re-operation or to display an alarm to the operator or the like.

Abstract: In a pump turbine which can be operated in a pumping mode or a generating mode by switching the rotating direction of a runner, the discharge passing through the runner is adjusted based on a wicket gate opening; the speed of the runner is sensed; a target speed is temporarily set to a first speed different from a rated speed on generation starting; a response speed of a speed control via discharge adjusting means is controlled to a lower level after the speed reaches the target speed than that before the speed reaches the target speed; and finally, the target speed is slowly led to the rated speed, thus enhancing the stability of the speed when the turbine is started and enlarging a head range in which synchronization is achieved.

Abstract: A pressure and flow control apparatus includes first to third pipes, fluid being supplied to the first pipe and outputted from the third pipe, a pressure control valve, a control valve, and a control unit. The pressure control valve is provided between the first and second pipes and opened or closed based on a first opening degree to control flow of the fluid from the second pipe to the third pipe. The control valve is provided between the second and third pipes and opened or closed based on a second opening degree to control flow of the fluid from the first pipe to the second pipe. The control unit determines the first opening degree, and determines the second opening degree based on the first opening degree and a pressure in the second pipe.

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 transfer function between the inlet air-flow consumed by a Gas Turbine engine, and the engine parameters of speed, pressure ratio, and Inlet Guide Vane (IGV) angle is described. An active compressor Operating Limit Line (OLL) management strategy that leverages this improved flow measurement transfer function is also described. The improved flow measurement capability afforded by the transfer function permits a deterioration in flow rate caused by compressor fouling to be detected. Using the deterioration in flow rate as a proxy for compressor fouling, a degraded surge boundary associated with fouling can be predicted, using a transfer function between degradation of air-flow along operating line and degradation of surge line. In combination, the inventive improvements in flow measurement and operating line management afford added compressor surge protection across the operating range, while permitting the attainment of elevated pressure ratios associated with high thermodynamic efficiency and output.

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: An object of the present invention is to provide a pump turbine capable of improving the stability of the governor by fully lessening the influences by the S-characteristics even when the running point of the pump turbine is in the S-characteristics region.

Abstract: A system includes a gas turbine engine having a shroud and a rotor with one or more blades. The rotor rotates within the shroud to pressurize a fluid during operation of the engine. An electromagnetic actuator is also included that is operable to move the shroud relative to the rotor to adjust clearance between the shroud and blades. In addition, a controller is included in this system to determine a desired amount of clearance in accordance with an operating mode of the engine. The controller generates an actuation signal to change the clearance in correspondence with the desired amount. The electromagnetic actuator responds to the actuation signal to provide the desired amount of clearance.

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: Centrifugal pump, in particular a hygienic centrifugal pump, provided with a primary and a secondary shaft seal (7,8) at the rear wall (2) of the pump chamber (1). Cooling flushing and barrier fluid is passed to and from a compartment (12) between these seals (7,8), optionally in a flushing fluid circuit. A sensor means (18) is provided in a discharge pipe (16) from the compartment (12) and adapted to measure at least the turbidity, electrical conductivity and temperature of the flushing fluid for activation of an alarm in case of leaking pump fluid through the primary seal (7). As a result the centrifugal pump is more sensitive to leaking pump fluid through the primary seal such that the pump activates an alarm (or optionally shuts down), if the leakage is too extensive.

Abstract: Fore many applications it is desirable to determine the operating level, i.e. the current flow rate V and the total pressure difference &Dgr;pt of a fan in the installed state without external measuring points and calibration. The invention should develop a suitable method and a corresponding fan. In the method of the invention, from a measured effective pressure difference &Dgr;pMw a flow rate V is determined and from that, via an operational characteristic curve a target value for the total pressure difference &Dgr;pst is found. By comparing the target value &Dgr;pst determined this way with its measured value &Dgr;pMt the operating level and its accuracy are determined. For this purpose on the fan of the invention measuring points are provided for measuring one or more effective pressure differences &Dgr;pMw and the total pressure difference &Dgr;pMt.

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 compressor stall margin during acceleration in a gas turbine engine includes means for sensing signals indicative of the gas flow temperature and gas pressure. The control system further includes signal processing means, responsive to the sensed signals, for synthesizing and providing a processed signal indicative of a measure of compressor destabilization due to heat transfer effects. The control system also includes means, responsive to the processed signal, for providing an output to initiate corrective action to increase compressor stall margin if needed. The engine control means, which is a part of the control system, increases the compressor stall margin by either adjusting the compressor variable vanes, reducing fuel flow or modulating the compressor bleed.

Abstract: A process for operating multistage turbocompressors (2, 22, 42) with a plurality of controllers (15, 35, 55) which interact one with each other, in which each compressor stage has anti-surge control valves (5, 25, 45) of its own, which recycle into the suction lines (1, 21, 41) of their respective own compressor stage (2, 22, 42). The control is performed by flow computers (6,26,46) for calculating the suction flow and computers (7,27,47) for determining the minimum acceptable flow from the delivery head. A comparison unit (12, 32, 52) determines the difference between the set point (derived from delivery head) minus the actual value (flow) and whenever the actual value is too low compared with the set point, it brings about a gradual opening of the corresponding surge line control valves (5, 25 and 45) until the actual flow exactly corresponds to the flow set point, which depends on the particular delivery head.

Abstract: A method and an apparatus for use with a gas turbine engine receive a signal indicative of an engine operating condition, generate signals representative of thermal conditions of a rotor, blades, and a case, and in response to each of the signals above, determine a signal indicative of a difference between a instantaneous clearance for the thermal conditions and a steady state clearance for the engine operating condition. The determination includes effects related to a temporary difference that results from a difference between the steady state clearance for the engine operating condition and a steady state clearance for a preceding engine operating condition, but does not require computation of the actual temperatures or the steady state temperatures of the rotor, the blades, and the case. A signal indicative of the difference between a instantaneous clearance for the thermal conditions and a steady state clearance for the engine operating condition may be provided to various augmentation schedules.

Abstract: For checking the operating reliability of a turbine during load shedding, input values having simulated time profiles are fed to a regulating circuit regulating a turbine. The reaction of the regulating circuit to the input values simulating load shedding conditions is subsequently measured. Changes in the regulating circuit are then detected by comparison with an earlier measurement.

Abstract: An impulse turbine comprises at least one runner keyed to a drive shaft in association with a distributor unit which has, for each runner, a circular outlet for the supply of fluid from the distributor unit to the blades of a respective runner. Each outlet is arranged coaxially inside the respective runner and the distributor unit is shaped in a manner such as to define a substantially circular path for the fluid and to cause the fluid to emerge from the distributor unit through the at least one outlet predominantly tangentially relative to the outlet.

Abstract: A cooling control apparatus controls a plurality of cooling members. The apparatus has a monitor which monitors states of predetermined combinations of the cooling members and a controller which controls the cooling members based on the states monitored by the monitor.

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 fluid passage extends through the compressor casing from a point near the tip of the impeller to a transducer located externally of the compressor casing. Responsive to fluctuations of pressure sensed by the transducer indicative of rotating stall, the compressor is controlled by varying the diffuser or shutting down the compressor, as is appropriate.

Abstract: The operation of quickly taking a turbocompressor off-line from a parallel configuration, of a gas pipeline compressor station, may encounter increased mechanical action (in particular, vibration) upon recycle piping and the additional risk of compressor surge. For these reasons, this invention relates to a method and apparatus for decreasing vibratory loads and for increasing surge prevention effectiveness, while initiating an off-line operation, by (1) altering the surge control line's location, at a preset rate, from its initial location to a predetermined new location; and (2) decreasing the turbocompressor's deceleration rate when the operating point intercepts the surge control line before the control line reaches its new location. Upon completion of the off-line activity, the control line returns to its initial location; and the reduction of compressor speed will cease on reaching a preset value.

Abstract: A turbine, disposed in water flowing therethrough, includes a hub and associated runner blades. Each blade comprises an inner surface and a distal outer surface, 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 hub includes a spherically-shaped outer surface in a region of the hub swept by the inner surface of the blades when the blades are rotated from maximum to minimum pitch. The hub may also be associated with blades in which the chord is reduced in the root region of the blade. The turbine may also include seals attached to the blade inner surface and an essentially spherically-shaped discharge ring to improve certain turbine parameters such as cavitation, efficiency, flow disturbance, and fish survivability.

Abstract: The stroking speed of an antisurge control valve is impeded by the combined damping effects of signal dead time and the inherent lag of ancillary pneumatic components within a primary control loop. Furthermore, as control valve actuator size increases, the negative influence of these two impediments (dead time and lag) is amplified. As a result, control valve response times are adversely affected; and the possibilities of surge-induced compressor damage and process upsets are heightened. For these reasons, this disclosure relates to a method for protecting turbocompressors from impending surge, and for preventing subsequent process upsets, by improving antisurge control. But more specifically, it describes a technique for decreasing damping effects by evacuating control valve actuators (diaphragm or piston) through restrictions having a lower resistance to compressible-fluid flow rather than through volume boosters--consequently, increasing a control valve's opening speed to that of an emergency shutdown.

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 features designed to shield a gap formed between the hub and the blade inner edge as the blade is rotated about its axis.

Abstract: Driven turbomachinery for use in centrifugal and mixed flow pump overcomes operational for overcoming difficulties, such as flow separation and generation of surge at low flow rates, often encountered in similar machines of the conventional design. The turbomachinery is provided with variable-angle inlet guide vane and variable-angle diffuser vanes, and the diffuser section is constructed according to a fluid dynamic principle, and the vanes having a wing shape are distributed tangentially so that the diffuser section acts as a centrifugal diffuser. A convenient operational parameter, chosen from such variables as input current to the drive motor, rotational speed or torque of the drive motor, inlet/exit pressures, and fluid velocity, is monitored during the operation by means of sensors strategically attached to parts of the operating system.

Abstract: A method of testing an actuation system for positioning an inlet guide vane, the actuation system including a primary electronic system, a secondary hydro-mechanical system is disclosed.

Abstract: A turbomachine having variable angle diffuser vanes is demonstrated with the use of a centrifugal pump. The performance of a diffuser is enhanced greatly by the use of adjustable angle diffuser vanes which can be set to a wide range of vane angles to provide a variable size of an opening between adjacent vanes. The demonstrated pumping system has a significantly wider operating range than that in conventional pumping systems over a wide flow rate, and is particularly effective in the low flow range in which known diffuser vane arrangements would lead to surge in the entire system and other serious operational problems. A number of examples and formulae are given to demonstrate the computational methods used to select a vane angle for a given set of operating conditions of the turbomachine.

Abstract: A technique for controlling compressor stall and surge is disclosed. In a gas turbine engine, static pressure asymmetry is sensed at a plurality of locations along the circumference of the compressor inlet. Time rate of change of the mass flow in the compressor is also estimated using pressure measurements in the compressor. A signal processor uses these signals to modulate a compressor bleed valve responsive to the level of flow property asymmetry, the time rate of change of the annulus average flow to enhance operability of the compressor.

Abstract: A turbocompressor's Surge Limit Line, displayed in coordinates of reduced flow rate (q.sub.r) and reduced head (h.sub.r), can be difficult to characterize if the slope of the line is small; that is, nearly horizontal. And it can be especially difficult to characterize if the surge line exhibits a local maximum or minimum, or both. This is often the case with axial compressors having adjustable inlet guide vanes, and for centrifugal compressors with variable inlet guide vanes and diffuser vanes. With their prime objective being the prevention of surge-induced compressor damage and process upsets, antisurge control algorithms should compensate for variations in suction conditions by calculating both the operating point and the Surge Limit Line, utilizing specific (invariant) coordinates derived by using the notations of similitude or dimensional analysis. The result is that the surge limit is invariant (stationary) to suction conditions.

Abstract: A method and apparatus for determining turbine rotor stresses in real time enables increased operation efficiency and more accurate stress determinations. The system calculates rotor bore and surface temperatures based on the time response of the rotor. The rotor surface temperature is measured using a sensor such as a thermocouple, and the measured rotor surface temperature is used to calculate rotor bore temperature and rotor average temperature based on time constants determined as a function of rotor geometry and material. The rotor surface thermal stress and the rotor bore thermal stress can be determined based on the measured and calculated temperatures.

Abstract: A turbomachinery is presented to provide stable operation at fluid flow rates much lower than the design flow rate without introducing surge in the device. This is achieved by providing a diffuser with variable angle vanes. The vane angle at low flow rates is adjusted so as to minimize the diffuser loss of the exiting fluid stream from the impeller. Since the flow angle of the exit flow of the impeller is a function only of the non-dimensional flow rates, and does not depend on the flow angle at the inlet the impeller, therefore, the vane angles can be regulated to achieve a stable operation of the impeller without producing surge of the turbomachinery at flow rates lower than the design flow rate. To optimize the performance of the turbomachinery, in addition to the variable angle vanes, an inlet guide vane having variable vane angle is provided so that the turbomachinery can be operated at the required flow rate and head pressure.

Abstract: Active recovery from a rotating stall operating condition in an axial flow compression system is accomplished by altering the temperature and/or density of the working fluid flowing in the inlet of the compression system once rotating stall is detected. A burner is used to increase the compressor inlet flow temperature and concomitantly reduce the inlet flow density. Alternatively, a low density gas such as helium is injected into the compressor inlet. The ingestion of high temperature gases or other low density gases into the compressor energizes a dynamic response from the compression system that induces rotating stall recovery.

Abstract: A method and system for optimizing performance of a Kaplan turbine power generating unit are provided wherein an optimal "N-dimensional" virtual cam is populated with gate and blade positional settings producing maximum power output for a set of N operating parameters. The preferred parameters include head, flow, power generation level, physical situation of the unit, operating state of neighboring units, trash rack loss and a parameter indicative of cavitation (such as relative submersion level). When the system detects a unique set of operating conditions for which optimization is needed, an iterative optimization search is performed for the best gate and blade positional settings, which are then saved in memory (populating the cam matrix) for subsequent use when the same operating conditions are encountered. The optimal matrix divides parameters having ranges into range segments and treats other parameters as having discrete states.

Abstract: Balancing the load between compressors is not trivial. An approach is disclosed to balance loads for compression systems which have the characteristic that the surge parameters, S, change in the same direction with rotational speed during the balancing process. Load balancing control involves equalizing the pressure ratio, rotational speed, or power (or functions of these) when the compressors are operating far from surge. Then, as surge is approached, all compressors are controlled, such that they arrive at their surge control lines simultaneously.

Abstract: A method of, and a system for, detecting an occurrence of a surge in a gas turbine engine. The method includes steps, executed during consecutively occurring time periods, of: obtaining filtered derivatives of first and second engine operating characteristics; comparing the filtered derivatives of the first and the second engine operating characteristics to first and second threshold values, respectively; and incrementing a count only if both of the filtered derivatives exceed their respective threshold values. Otherwise, a next step decrements the count if one or both of the filtered derivatives do not exceed their respective threshold values. The method further includes a step of indicating a surge condition only if the count is equal to a predetermined value that is greater than unity. In a presently preferred embodiment of this invention the engine is a turbofan engine, the first engine operating characteristic is fan speed, and the second engine operating characteristic is exhaust gas temperature.

Abstract: A control system prevents recurrence of surge in a dynamic compressor. An anti-surge valve bypasses flow and is operated by the control system between a low limit and a full open position. The low limit is initially established to be zero, or a fully closed anti-surge valve. In the event of a compressor surge, the system detects a position of the anti-surge valve at the onset of surge, and stores a position related to the detected position as a new low limit. The stored position is preferably the detected position plus a small increment in order to prevent recurrence of the surge event.

Abstract: A turbomachine having variable-angle diffuser vanes operates by regulating the angle of the diffuser vanes on the basis of the sensors disposed on the pump body or pipes of a surge detection device. The onset of surge can be forecast by measuring the fluctuations in the operating parameter(s) over a measuring interval of time computed on the basis of the operating characteristics of the impeller of the turbomachine. The onset of surge is prevented by adjusting the angle of the diffuser vanes in accordance with the sampling duration for parameter fluctuations over the measuring interval of time, and by adjusting the diffuser vanes to maintain the operating parameter fluctuations of the fluid machinery below a threshold value of the turbomachine derived from the design flow rate of the turbomachine. Application of the surge detection device in combination with fluid flow guide vanes and blades of the turbomachine enables full utilization of the potential capability of the turbomachine.