Abstract: A converter assembly for providing a liquid in a measuring line includes a stationary housing and a component being rigidly connected to the housing. A journal is slidingly supported in the stationary housing and defines a gap disposed between the component and the journal forming a throttle. The journal has an axis of rotation, an end, at least one transverse bore formed in the journal, and a journal bore formed in the journal from the end along the axis. The housing has a groove formed therein surrounding the journal and communicating with the journal bore through the at least one transverse bore. A liquid flow path communicates with a reservoir at a primary pressure and a pressureless sump and includes the throttle, the groove, the transverse bore and the journal bore. A measuring line branching off from the path between the transverse bore and the throttle carries the liquid at a measurement pressure corresponding to a rotational speed of the journal rotating about the axis.

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: Compressors for processes, as used for refrigeration systems applied to ethylene production, are multiple stage machines; furthermore, sidestreams enter/exit between the stages. Since a flow measurement device is not available between stages, and the gas temperature entering most stages is unknown, it is difficult to calculate an accurate value for reduced flow for antisurge control purposes. A new method is described, whereby reduced flow alone is replaced by the product of the reduced flow and the equivalent speed. This allows accurate calculation of the distance of the operating point to the surge line since the inlet temperatures into the separate compression units (except the first) are not necessary. The invention described herein can be applied to multistage compression systems for a variety of processes.

Abstract: A compressor has inlet guide vanes, rotor blades and stator blades. To prevent rotating stall, baffle vanes 5 capable of having their angles varied are installed upstream of the inlet guide vanes, actuators to vary the angles of baffle vanes are coupled to the baffle vanes, sensors installed upstream of the baffle vanes detect a rotating stall condition inside the flow passage of the compressor, and a control unit is responsive to signals from the sensors to output control signals to the actuators to vary the angles of the baffle vanes so as to prevent the rotating stall condition. Instead of the baffle vanes, fluid jets may be provided upstream of the inlet guide vanes for the same purposes.

Abstract: A method of controlling the operation of a centrifugal compressor in a water chiller system. The compressor's capacity is variable by modulating its speed of rotation or by modulating its inlet guide vane's position. The water chiller includes an evaporator having a leaving water temperature. The method comprises the steps of: monitoring the leaving water temperature; determining if the leaving water temperature is in a steady state; modulating the compressor capacity by modulating speed of rotation if the leaving water temperature is in a steady state; and modulating the compressor capacity by modulating inlet guide vane position if the leaving water temperature is not in a steady state.

Abstract: In a method and a device for the closed-loop control of a turbine-generator configuration, a turbine control element is supplied with a first correcting variable and an exciter control element is supplied with a second correcting variable. The correcting variables in each case are formed from at least one reference value. In order to ensure reliable closed-loop control, the first correcting variable for the turbine control element is composed of at least two partial correcting variables. One of the partial correcting variables is derived from the reference value for forming the second correcting variable for the exciter control element.

Abstract: A water level regulating system controlling the water level of a head tank of each of a plurality of hydroelectric plant installed in cascade along a stream by using an opening of guide vanes of a hydraulic turbine as a manipulated variable, and the water level of the head tank as a controlled variable. Each hydroelectric plant has a water level regulator constituting the water level regulating system. Each of the water level regulator of an upstream hydroelectric plant and the water level regulator of a downstream hydroelectric plant has a device varying PID parameters for controlling the water level in accordance with the opening of the guide vanes, and a device varying a reference water level to a set water level.

Abstract: A controller for controlling the capacity of a centrifugal chiller compressor. The compressor is driven by an electric motor and has variable inlet guide vanes that control the flow of refrigerant to the compressor. The controller establishes a dimensionless plot of possible points of compressor operation relating the pressure coefficient and the capacity coefficient of the compressor. The current operating point of the centrifugal compressor is located on the plot and a dynamic surge boundary control curve is positioned proximate a region of actual surge. Control is exercised responsive to the variations of the region of actual surge and the surge boundary control curve for controlling compressor capacity by varying the opening of the inlet guide vanes and varying the speed of the compressor to move the operating point of the compressor proximate the surge boundary control curve.

Abstract: Linear electric actuators powered by DC brushless servomotors are individually controlled to position steam turbine valves by way of levers, pins and links to thus eliminate hydraulics and the attendant disadvantages of fluid filtering, conditioning and leakage as well as obtaining more flexible individual valve control, vis-a-vis, camshaft operated hydraulic actuators. Additionally, low friction actuators and springs are employed to automatically close the turbine valves in the event of a power failure.

Abstract: A method and apparatus for controlling working fluid surge in a centrifugal compressor include preventing surge by using a variable-speed prime-mover to achieve a minimum desired surge margin. Surge prevention is also accomplished by continuously modulating a blowoff valve to maintain an actual compressor pressure ratio at a predetermined target maximum value. Surge detection is accomplished by monitoring the time rate of change of the final stage discharge pressure.

Abstract: A method of operating a multistage turbocompressor or of monitoring the pump limit thereof, whereby the pump limit function is stored in the control unit in the form Y=m.F+b and the coefficients m and b are determined by the linear relationshipsm=m.sub.0 +m.sub.1.dT.sub.s +.SIGMA.m.sub.2i.dT.sub.rib=b.sub.0 +b.sub.1.dT.sub.s +.SIGMA.b.sub.2i.dT.sub.riwhere T.sub.s and T.sub.ri represent the intake temperature and the backcooling temperatures following coolers after each turbocompressor and dT.sub.s and T.sub.ri and reference temperatures T.sub.ref. The system automatically compensates for the shift of the pump limit with temperature and allows operation closer to the pump limit or boundary for stable aerodynamic operation.

Abstract: In conjunction with a method and apparatus for regulating the power of a steam power plant block, an improved method and an improved apparatus for restoration of a given throttling of the turbine inlet valves as a conclusion to a regulating process for stabilizing a sudden or abrupt elevation of the load set point is proposed by the invention. The necessary storage of fresh steam takes place without influencing the electrical output power or the regulating devices necessary for regulating it with the aid of a separate closed control circuit.

Abstract: The deflection angle of a gas turbine stator is adjusted in proportion to the difference between two parameters computed from N.sub.2 and TT2 using the same function generator. One parameter is a reference adjustment under standard conditions for measured N.sub.2 adjusted to sea level and standard temperature. The second parameter is an adjustment for actual altitude conditions. The parameters manifest the clearance between the engine case and the turbine blade tips.

Abstract: Stall margin in a gas turbine compressor is controlled during acceleration by synthesizing the thermal enlargement of critical compressor stages to synthesize the temporary increase in blade-case clearance during acceleration. The change in clearance is used to produce an augmenting stator vane deflection signal which is summed with a steady state vane deflection signal to increase deflection during acceleration until the clearance returns to a nominal level when the expansion of the compressor parts stabilize.

Abstract: A method of controlling a centrifugal compressor having a variable width diffuser section, the compressor being part of a chiller having a condenser and an evaporator, the method including the steps of defining the width of the diffuser which results in an optimum noise and performance level at given values of an operational parameter of the compressor, periodically sensing the operational parameter of the compressor, and periodically varying the diffuser width according to the sensed operational parameter to create a diffuser width that results in the optimum noise and performance levels at the sensed value of the operational parameter. The step of defining preferably defines the width based at least on the capacity at which the compressor is operating. The capacity is preferably determined by measuring the flow and temperature difference of the fluid passing through the evaporator. A control system for controlling the chiller system to minimize noise is also disclosed.

Abstract: This invention discloses a bearing device for a high speed rotary shaft comprising a functional bearing disposed on a shaft which is supported rotatably on a housing by a pair of bearings, and capable of supporting rotatably the shaft, a rotation sensor for detecting the revolution of the shaft and a controller for changing the functional bearing to a shaft supporting state in response to a rotation detection signal from the rotation sensor representing that the number of revolution of the shaft is above a predetermined number of revolution. When the shaft rotates at a low speed, the functional bearing is set to a free state and the shaft is supported at two points on the housing by the pair of bearings alone. When the shaft rotates at a high speed, the functional bearing is operated so that the shaft is supported at three points on the housing to prevent the occurrence of deflection of the shaft.

Abstract: An apparatus includes a compressor for compressing fluid including a sensor capable of sensing at least one function relative to the operation of the compressor. A controller controls the compressor causing the value of said one function to be within a predetermined parameter. A computer overrides the independent response of the controller wherein the controller acts in response to the computer, the computer being separate from said controller. The computer may act as a sequencing computer or as a test computer.

Abstract: Parameters indicative of gas turbine engine operational characteristics are sensed and the signals processed to derive further operational characteristic information therefrom, each information signal being compared in a subroutine to a corresponding threshold signal for exceedence thereof, the magnitude of each threshold signal being indicative of incipiency of compressor stall, a counter being incremented in the subroutine upon any threshold exceedence occurrence, the amount of counter increment depending on the ability of each information signal to predict the incipiency of stall, the higher the counter value the greater the stall incipiency. The counter is decremented during each subroutine execution, the counter value during the current subroutine execution being compared to that of the previous subroutine execution to determine the direction of stall incipiency. The counter is utilized as a bias signal to an engine acceleration schedule to vary the rate of acceleration as the counter is varied.

Abstract: A propeller speed governor having a derivative feedback of propeller speed and having a means such as a switch to open the derivative feed back loop when airspeed exceeds a predetermined amount is shown and described. This derivative inhibit is used to provide improved dynamic compensation at high and low speeds.

Abstract: A surge control system for a compressor comprising a bypass passage controlled by a bypass valve to return flow to the compressor inlet for avoiding surge in the compressor. The bypass valve is controlled through a sensing of a compressor speed and flow. The compressor speed and the square root of the flow signal, which is proportional to the actual flow, are presented as a ratio for comparison with an empirically established constant. When the conditions of the compressor system are such that the ratio approaches the constant, the bypass valve is opened and the compressor experiences increased flow therethrough.

Abstract: A propeller overspeed governor logic and control is described in this invention. A method is shown for providing a variable propeller pitch rate from a discrete pitch command to improve governing dynamic characteristics.

Abstract: Method and apparatus for operating compressors to avoid surges. The compressor is controlled by direct measurement of the rate of volumetric flow, Q, of gas through the compressor via the use of an acoustic flow meter, or other sonic velocity measuring device in combination with a standard flow meter and the measurement of the speed, N, of the compressor. The Q/N ratio is calculated electronically and output to a controller which, through a control circuit, operates a recycle valve in a by pass line leading from the discharge side to the suction side of the compressor. The Q/N ratio measured by the controller at compressor operating conditions is compared with a Q/N ratio at which surge will occur. When the measured Q/N ratio is less than the Q/N ratio at surge, the recycle valve will open and flow gas from the discharge side to the suction side of the compressor to avoid surge flow in the compressor.

Abstract: A method is disclosed for efficiently protecting dynamic compressors from surge under changing inlet conditions and in response to flow disturbances of varying size and speed. An antisurge control system based on this disclosed method will compute the relative proximity of the compressor operating point to its surge limit as a multi-variable parameter which is self-compensated for changes in gas composition, inlet temperature and pressure, compressor efficiency, guide-vane position, and rotational speed. A combination of adaptive closed- and open-loop control responses is used to maintain a margin of safety between the operating point and the surge limit. Both the safety margin and the magnitude of the open-loop response are proportional to the rate at which the operating point approaches the surge limit, thus maximizing process efficiency.

Abstract: A method for reliably operating turbocompressors in which flow and forwarding pressure defining the operating point of a compressor are continuously measured. At least one blow-off valve or blow-around valve is opened by a blow-off regulating system to prevent surging once the operating point of the compressor has attained a blow-off curve that parallels a surge limit, but before the operating point can attain the surge limit so that the flow will attain a minimum level depending on the forwarding pressure. The speed at which the operating point moves relative to the blow-off curve or surge limit is determined continuously to obtain the opening of either one of the valves ahead of time. The blow-off valve or blow-around valve is opened at maximum speed by a procedure that supercedes a normal blow-off regulation system when the operating point has arrived at or beyond a rapid valve-opening curve representing a speed-dependent minimum distance of the operating point from the blow-off curve.

Abstract: A method and apparatus for controlling the surge limit of a turbocompressor utilizes continuously measured pressure and temperature values at the suction and outlet sides of the compressor. A relief valve connected to the outlet side of the compressor is controlled as a function of the distance between a working point and a surge limit line or blow-off line of a characteristic graph produced by characteristic graph coordinates that are computed using the pressure and temperature values. The actual value of another operating parameter that is independent of the pressure and the temperature values, such as the speed of the turbine for the turbocompressor, for example, is used. This operating parameter defines a family of characteristic lines on the characteristic graph. A set-point value for the characteristic graph coordinates is then obtained using the characteristic line of the operating parameter which passes through the working point.

Abstract: In one form of the present invention, turbine cooling air is modulated as a function of engine speed, altitude, and blade temperature.

Abstract: To prevent a compressor from pumping, a blow-off or reorientation valve branched off its outlet is controlled by a controller as a function of the working point location of the compressor relative to a blow-off line defined in the characteristic field. According to the invention, the differential component of the controller behavior, in particular, the time constant governing the differentiation, is so controlled as a function of the working point location that the differentiating effect is great near the blow-off line and sight at a greater distance from the blow-off line.

Abstract: A turbine control device which compensates for non-linearity of the degree-of-opening/flow-rate characteristic of a regulating valve. The device has a turbine rotation speed detector, a calculator to determine a desired flow rate based on a predetermined rotation speed and the detected speed, a valve for controlling the flow rate with a variable degree of opening, a flow rate detector, a memory unit for memorizing combinations of the detected flow rate and respective degrees of opening of the valve, a converter for converting the desired flow rate into a valve opening command signal based on the memorized combinations of the flow rate and respective degrees of opening of the valve, and a servo controller for the valve.

Abstract: A system (method and apparatus) are disclosed for detecting pressure surges in a turbo-compressor. Either the gas flow rate or gas velocity is measured at the intake or the outlet port of the compressor to produce a signal X. The rate of change of this signal X is determined and represented by a signal Y. The occurrence of surge is sensed and indicated by an output signal Z when the signal Y exceeds a prescribed threshold value.

Abstract: Blood flow rate in a motor driven centrifugal blood pump is measured indirectly and non-invasively by sensing a first parameter representative of pump RPM and a second parameter representative of motor torque. The blood flow rate is computed as a function of the first and second parameters. By measuring the second parameter in a zero flow condition while the motor is being driven at a known RPM, a viscosity calibration factor is determined which is used, together with the first and second parameters in the calculation of flow rate.

Abstract: Stator blades and rotor blades are cooled by discharge air discharged from an air compressor coupled directly with gas turbine. A signal of the compressor discharge pressure and a signal of turbine exhaust gas temperature are obtained, and cooling air flow is controlled based on these signals.

Abstract: A turbine shutdown control system for controlling a turbine powering two load groups. Upon loss of one load group, a first control valve will close to interrupt the fluid flow to the turbine. A second modulating valve in parallel with the first valve remains open to provide sufficient fluid flow to the turbine to power the second load group.

Abstract: A control system for a steam turbine which system includes apparatus for adjusting steam flow to regulate turbine shaft speed and a transducer for providing signals indicative of turbine shaft speed, is provided with a feedback control system which modifies the shaft speed as a function of torque of the turbine. The feedback control system regulates a speed command signal which modifies the operation of the steam flow adjusting apparatus to thereby limit torque. The torque signal is developed by measurement of first stage shell pressure in the steam turbine and conversion of a signal representative of pressure to a signal representative of torque. In one embodiment, the conversion process involves utilization of plural look-up tables in a microprocessor implemented control system. The look-up table data is provided from characteristic curves of the steam turbine.

Abstract: To prevent surge in a compressor, the flow therethrough is automatically altered when the static pressure differential taken laterally across one of its diffuser vanes approaches a magnitude indicative of a surge condition.

Abstract: A method and arrangement for controlling the operation of turbo compressors, particularly those of high capacity, utilizes flow rate and pressure values for an analog controller as well as a computing circuit to optimize the operation of the compressor. The compressor is assumed to have a characteristic basic linear blowoff line and an optimum non-linear blowoff line on its pressure/flow curve. The calculating or computing circuit computes an error signal representing a difference between the basic and optimum blowoff line at an operating pressure and applies the signal to the analog controller which controls the compressor to its optimum extent. An analog system connected to the controller maintains control at least according to the basic blowoff line if the computing circuit fails.

Abstract: An apparatus for the monitoring of physical quantities on systems for example for driving a quick-closing valve in turbines, wherein the monitoring itself is performed by monitoring channels which are interconnected in a majority-determining switching logic, primarily 2 of 3 system. The monitoring channels (I, II, III) are formed by a system-dependent number of identical solenoid valves (1, 2, 3).

Abstract: A turbine engine is constructed to passively modulate the flow of cooling air into the shroud. Sealing rings are disposed relative to the cooling air inlets in the shroud such that pressure and temperature variations in the engine will cause the cooling air inlets to be either fully opened, completely blocked by the sealing ring, or modulating therebetween in accordance with the cooling needs of the shroud.

Abstract: A microprocessor-based controller for an extraction type steam turbine-generator unit capable of selecting from a variety of predetermined control strategies and implementing corresponding valve position control loops by generating appropriate valve position control signals in accordance with operator-chosen setpoint signals and turbine operating level signals. In a particular control strategy, automatic system frequency correction is achieved in a load control mode upon separation of the turbine-generator from the utility power grid, by detecting turbine speed deviation beyond predetermined limits and correcting turbine speed to synchronous speed without the need for operator intervention.

Abstract: A surge detection apparatus for use in a refrigeration system having a centrifugal compressor driven by an electric motor includes a first pressure transducer for sensing a condenser pressure and a second pressure transducer for sensing an evaporator pressure. A first bandpass digital filter responsive to the condenser pressure and the evaporator pressure is provided for generating a first signal representative of the rate of change of the pressure developed across the compressor. A current transformer is used to sense a current in the electric motor driving the compressor. A second bandpass digital filter responsive to the motor current is provided for generating a second signal representative of the rate of change of the RMS current being drawn by the compressor drive motor. A third signal representative of a differential pressure threshold and a fourth signal representative of a first motor current threshold and a second motor current threshold are provided.

Abstract: Liquid injection into the interstage steam flow in a multi-stage compressor is controlled by calculating a saturation temperature of the fluid in the interstage and then controlling the liquid flow to reduce the incoming fluid temperature to a value a predetermined amount above the saturation temperature. In one embodiment, the fluid temperature is measured at the downstream end of the interstage conduit after it has been reduced by liquid injection. This measured temperature is used to compare with the calculated saturation temperature to determine whether to increase or decrease the liquid injection flow. In another embodiment of the invention, the fluid temperature is measured upstream of the liquid injection point.

Abstract: An adjustable gain controller for a steam turbine valve position control loop includes an electronic operator, a proportional controller, a derivative controller and an integral controller. A steam flow condition error signal is amplified by the reciprocal of the valve's regulation value. The amplified error signal is supplied to the electronic operator and to the integral controller. The electronic operator includes means for initially selecting a value of A and n and generating a gain factor from a nonlinear gain characteristic function utilizing those values in combination with the valve's regulation value and the normalized error signal. The electronic operator multiplies the amplified error signal by the gain factor and applies the resultant signal to the proportional controller and the derivative controller. The output signals from the proportional, derivative and integral controllers are summed together and that sum is input into an electrohydraulic valve actuator system.

Abstract: A microprocessor-based controller for an extraction type steam turbine-generator unit capable of selecting from a variety of predetermined control strategies and implementing corresponding valve position control loops by generating appropriate valve position control signals in accordance with operator-chosen setpoint signals and turbine operating level signals. The extraction mode of turbine operation is subdivided into a provided set of mutually exclusive extraction control loops, each of which can be placed in service in a bumpless fashion upon transition from any other extraction control loop in a predetermined sequence. Upon a return from the manual mode of turbine operation to the automatic mode, a particular extraction control loop is automatically placed in service without the need for operator intervention.

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a rotating brushless exciter generator coupled to a power system through a breaker. One or more of the turbine-generator plants are operated by a hybrid digital computer control system during sequenced startup, synchronizing, load, and shutdown operations. The program system for the computer and external analog circuitry operate in a multiple gas turbine control loop arrangement. Automatic synchronization is achieved with a hybrid subsystem which includes the programmed computer and external phase detection circuitry. An automatic synchronization program for the computer is divided into rough speed and voltage matching, fine speed matching and breaker closure subprograms.

Abstract: A first control assembly is provided operative to supply gas from a supply of gas under pressure to the inlet of a centrifugal liquid pump at increasing and decreasing rates responsive to decreases and increases in the pressure of liquid discharge from the pump. The first control assembly includes spring structure for closing an associated air flow controlling valve member which is yieldingly biased toward the open position by the pressure of liquid discharged from the pump and a second control assembly is provided operative to increase and decrease the loading of the aforementioned spring structure responsive to increases and decreases in demand for liquid being discharged from the pump.

Abstract: A monitoring system for a screw compressor for checking the operating conditions of the screw compressor by opening and closing a suction throttle valve located on the suction side of the screw compressor and an air discharge valve located on the discharge side thereof to thereby effect on-off control of the flow rate of the discharged air, wherein the operating conditions of components of the screw compressor are checked both in on-load and unloaded conditions by comparing values of the suction pressure, discharge pressure and discharged air temperature of the screw compressor with respective preset values.

Abstract: A multistage hydraulic machine in which respective pressure stages are connected in series through return passages and the highest and lowest pressure stages are provided with movable guide vanes the degrees of openings of which are variable is controlled in load adjustment or in response to the change of a static head under a steady operation condition by controlling the degrees of openings of the movable guide vanes of the highest and lowest pressure stages in accordance with several modes.

Abstract: A steam generation system employing a flash tank feeding low-pressure steam to a compressor controls surges in the compressor by calculating the amount of steam generated based on the temperature change and flow of water passing through the flash tank and modulates the flow rate in order to maintain the steam flow above a surge limit. If increasing the water flow rate is incapable of producing enough steam to avoid surges, a recycle control recycles steam from the output of the compressor back to the flash tank. A further embodiment of the invention permits using an auxiliary source of low-pressure steam to augment the steam produced in the flash tank while maintaining the total steam flow at a level sufficient to avoid surges. The steam flow may alternatively be derived from the differential pressure between outlet and inlet of the compressor.

Abstract: An apparatus for pumping a liquid stored under pressure without pressure-induced, liquid leakage during seal failure. The liquid or slurry being pumped is usually of a type that is difficult to handle, e.g., liquids which are volatile, poisonous, corrosive or a combination of these characteristics.The apparatus comprises in combination a vessel capable of containing a liquid under pressure; a vertical pump with its inlet port in communication with the vessel; an equalizing line connecting the shaft housing of the pump with the vapor space of the vessel; and a shaft seal located within the pump above the equalizing line connection so that the vessel and the shaft housing can be pressure-equalized during seal failure.The apparatus further provides pressure sensitive switching means so that the pump can be isolated upon occurrence of a specified pressure change within the vessel.

Abstract: A DEH (digital electrohydraulic) control system for a steam turbine generator having a steam bypass system. The turbine system includes a high pressure turbine having throttle and governor steam admission valves as well as an intermediate pressure turbine having stop and interceptor steam admission valves. The turbine is brought on line by initially controlling steam admission into the intermediate pressure turbine by modulating the interceptor valve in response to a speed error signal generated as a result of the difference between actual and a predetermined reference speed. During this initial control the throttle valve remains in a closed position. When the turbine speed has attained a preset value such as half of synchronous speed, the interceptor valve is held at the same position it was in when the preset speed was attained and the throttle valve is controllably open in response to the same speed error signal.

Abstract: A surge control system is disclosed for centrifugal compressors which utilizes an algorithm to calculate a desired orifice differential pressure and compare the calculated result with an actual differential pressure. A controller is provided for operating a blow-off valve to bring the actual differential pressure to the calculated differential pressure.