Abstract: A gas turbine engine includes a turbomachine including a compressor section, a combustion section, a turbine section, and an exhaust section arranged in serial flow order and together defining at least in part a core air flowpath. The gas turbine engine also includes a thermal management system including a flowpath heat exchanger coupled to, or integrated into, one or more components of the compressor section, the combustion section, the turbine section, or the exhaust section such that the flowpath heat exchanger is directly thermally coupled to an airflow through the core air flowpath.

Abstract: A system and method for detecting a shaft break in a turbofan gas turbine engine includes sensing fan rotational speed and sensing turbine engine rotational speed. A rate of change of rotational speed difference between the sensed fan rotational speed and the sensed turbine engine rotational speed is determined in a processor, and a determination that a shaft break has occurred is made in the processor based at least in part on the rate of change of the rotational speed difference.

Abstract: A centrifugal heat pump system includes a steam system with a steam supply, a steam turbine and a steam condenser connected in a steam loop; and a refrigerant system including a first compressor and a second compressor, a refrigerant condenser, and an evaporator connected in a refrigerant loop. The steam turbine includes a rotary drive shaft disposed axially and extending from a first end and a second end of the steam turbine. A sump system collects and redistributes oil or other lubricating fluid. The first compressor is coupled by a first coupling device to the first end of the steam turbine drive shaft and the second compressor is coupled by a second coupling device to the second end of the steam turbine drive shaft. The first and second compressors are connected in parallel in the refrigerant loop and controlled to share a cooling load equally.

Abstract: There is provided a system and method for controlling an engine. A request signal indicative of a demand for the engine to output a required power level is first receive. A position control signal is then generated in response to the request signal. The position request signal is indicative of a first request for adjusting a present position of a variable geometry mechanism of the engine towards a commanded position to achieve the required power level. An acceleration rate control signal is further generated on the basis of the position control signal. The acceleration rate control signal is indicative of a second request for adjusting an acceleration rate of the engine in accordance with the commanded position of the variable geometry mechanism. The position control signal and the acceleration rate control signal are then output to the engine.

Abstract: One of a controllable load and a fuel flow to a single-spool turboshaft engine is controlled so that a rotational speed of a single-spool turboshaft engine is substantially regulated to a level corresponding to a corrected rotational speed command, and the other of the fuel flow and the controllable load is controlled so that a torque transmitted from the single-spool turboshaft engine to the controllable load is substantially regulated to a level corresponding to a corrected torque command. Under at least one operating condition, the corrected rotational speed command is determined so as to minimize or nearly minimize a measure of fuel consumption by the single-spool turboshaft engine when operated so that the torque transmitted to the controllable load corresponds to the corrected torque command.

Abstract: A method is provided for the measurement of parameters of a gas present in a gas turbine combustion chamber. The method includes tuning a laser to a range containing the absorption lines of species to be analyzed in the gas, and directing the laser light through the combustion chamber and detecting laser light reflected off boundary walls of the combustion chamber. In order to analyze the absorption spectrum measured at high temperatures and pressures, a signature recognition algorithm is applied to the spectrum. The measured absorption spectrum is cross-correlated with a calibration absorption model spectrum for the absorption lines at several temperatures, pressures, and concentrations generated prior to the measurement. Values for pressure, temperature, and concentrations of selected species in the gas are determined simultaneously allowing direct control of the combustion chamber process. An apparatus for carrying out the method is also provided.

Abstract: A controller receives a power-level command representative of a level of power to be transmitted by a single-spool turboshaft engine to a controllable load. A torque command determined responsive to a measure of inlet pressure, from a control schedule responsive to the power-level command, is representative of a level of torque to be transmitted by an element to drive the controllable load. Under some operating conditions, a rotational speed command provides for at least nearly minimizing a measure of associated fuel consumption when the transmitted torque is regulated to the level corresponding to the torque command by controlling one of the controllable load and a fuel flow to the engine, and the other of the controllable load and the fuel flow to the engine is controlled so as to regulate an associated rotational speed to a level corresponding to the rotational speed command.

Abstract: A fuel supply device includes a fuel supply pipe receiving fuel at a non-regulated pressure delivered by a pump, a device for measuring the flow rate of fuel in the pipe, a first controlled variable-restriction valve mounted in the supply pipe, a control system connected to the flow rate measurement device and to the first valve to control the valve to deliver fuel to the engine at a desired flow rate under normal operating conditions of the engine, a second controlled variable-restriction valve mounted in the supply pipe in series with the first valve, and a control for controlling the second valve to enable the engine to be supplied with fuel at an adjustable, reduced flow rate in response to detecting over-speed or over-thrust of the engine.

Abstract: A method and systems for controlling a thrust output of a gas turbine engine are provided. The system includes a first sensor for measuring a first engine operating parameter, a second sensor for measuring a first engine condition parameter, and a processor programmed to determine an expected value of the first engine condition parameter and determine a first variance value using a difference between the expected value of the first engine condition parameter and the measured first engine condition parameter. The processor is further programmed to determine a trim value using the first variance value and a first engine operating parameter demand and to determine a modified operating parameter demand based on the nominal operating parameter demand and the determined trim value. The system also includes a controller coupled to the processor for controlling engine thrust based on the modified demand of the first engine operating parameter.

Abstract: A method for operating a wind turbine based on operating profiles for the wind turbine corresponding to operating modes. The method includes defining operating modes and acquiring a plurality of parameter values, each based on a reading from a sensor of the wind turbine. Each of the parameter values is associated with one of the operating modes to create a wind turbine operating profile for each mode. The wind turbine is controlled based on the operating profiles.

Abstract: A control system and method for interactive startup and shutdown of a steam turbine driven chiller unit is provided. The chiller unit includes an integrated central control panel to control operation of both the steam turbine system and the refrigerant system. The central control panel has startup control system to assist an operator manually start the steam turbine system and the refrigerant system and a shutdown control system to assist an operator manually shutdown the steam system and the refrigerant system. Both the startup control system and the shutdown control system include logic for performing necessary protective actions and for notifying an operator when to perform required actions.

Abstract: A turbine overspeed control system for use with a gas turbine engine of a gas turbine electrical powerplant. The overspeed control system preferably comprises a first and second overspeed control subsystem. When an overspeed condition of the gas turbine engine is detected, the first overspeed control subsystem acts to remove air from a combustion section of the engine, while the second overspeed control subsystem operates to alter the angle at which an incoming flow of air is supplied to a compressor turbine located therein. The result of operating the first and/or second overspeed control subsystem is a reduction in the speed of the gas turbine engine that is much more rapid than can be accomplished by simply shutting off a fuel supply thereto.

Abstract: A control system and method are provided for the automatic startup and shutdown of a steam turbine driven chiller unit. The chiller unit includes an integrated central control panel to control operation of both the steam turbine system and the refrigerant system. The central control panel has a startup control system to automatically start the steam turbine driven chiller unit while performing necessary protective actions and a shutdown control system to automatically stop the steam turbine driven chiller unit while performing necessary protective actions.

Abstract: A method for monitoring engine performance includes sampling exhaust gas temperature associated with a turbine engine over an interval of operational time of the turbine engine. The method further includes applying a first test to identify statistical outliers on the sampled exhaust gas temperature data and removing identified statistical outliers from the sampled exhaust gas temperature data. Subsequently, the method includes applying a second test to identify step changes in slope of the exhaust gas temperature data and dividing the interval of operational time into one or more segments based upon the identified step changes. Finally, the method includes determining a slope for each segment and combining the segments to obtain a rate of performance deterioration of the turbine engine.

Abstract: Apparatus for controlling the power output efficiency of a power generation system based on an operator input. A processor is coupled to the input means and (i) receives the generated operator command, (ii) receives a plurality of detected ambient air conditions, (iii) receives a plurality of detected engine performance parameters, (iv) determines first and second engine control commands based on the received pilot thrust command, the detected ambient environmental conditions, and the engine performance parameters, and (v) outputs control commands to optimize the efficiency of the power generation system.

Abstract: A microprocessor-based control system for a gas turbine electrical powerplant the microprocessor-based control system controls the startup, operation, and shutdown of the gas turbine electric powerplant. The microprocessor-based control system of the present invention dispenses with the need to utilize relays, timers, or other control hardware. Rather, the microprocessor-based control system employs software that replaces the control hardware, and directly reads the inputs, calculates the control actions, and writes the outputs. The microprocessor-based control system is also in electrical communication with an overspeed control system, provided to ensure that a runaway condition of the gas turbine engine does not occur should the gas turbine engine become disconnected from the speed reducer (gearbox) or generator. Sensors are used to monitor multiple operating conditions of the powerplant.

Abstract: An electronic engine controller is provided in which a backup controller or independent protection module is located in a sealed housing 8 which itself is located within the main housing 4 of the controller. The backup controller is thermally insulated such that it has enhanced durability in the event of a fire or the like occurring in the vicinity of the controller.

Abstract: The exchange, removal or addition, as applicable, of media and/or power is provided between the individual shafts of an engine, between individual engines and between the engines and the aircraft. Thus, additional degrees of freedom are provided, enabling engine parameters to be addressed in terms of a reduction or avoidance of negative resonances or beats. It also provides an ability to alter thrust from engines of a multi-engined aircraft to reduce rudder trim.

Abstract: The present invention provides a rocket engine (10) that is self-compensating on nozzle thrust coefficient for varying ambient backpressures. The rocket engine (10) includes a combustion chamber (12) having an injector end (14) and a nozzle end (16). A propellant injector (20) is in fluid communication between a propellant line and an inside periphery of the combustion chamber injector end (14). A nozzle throat (18) is formed at the nozzle end (14) of the combustion chamber (12). A nozzle exit cone (22) extends outwardly from the nozzle throat (18). A plug support (30) is coupled between a nozzle plug (28) and the propellant injector (20). The nozzle plug (28) aerodynamically self-compensates for changes in ambient backpressure at the nozzle exit cone (22) such that the nozzle thrust coefficient is maximized for any ambient backpressure.

Abstract: A controller is provided in which an independent protection controller is provided in a casing, which casing is disposed within the casing for the main controller, such that the protection controller is provided as a box within a box. This allows the casing for the main controller to provide extra protection to the protection controller against mechanical stress and damage.

Abstract: In a control system for a gas turbine aeroengine having a control unit made up of an electronic control unit (ECU) which calculates a fuel flow rate command value based at least on the detected rotational speed of the turbine and the desired power output and a fuel control unit (FCU) including at least a fuel metering valve which meters fuel to be supplied to the engine based on the calculated fuel flow rate command value, the ECU is integrally connected to the FCU, thereby reducing the size and weight of the control units and hence, reducing the occurrence of resonance which would otherwise be likely to occur. In the system, an alternator is integrally connected to the FCU and the rotational speed of the turbine is detected based on the wave form generated by the alternator. Moreover, the ECU calculates the fuel flow rate command value such that the fuel flow rate to be supplied to the engine is brought to a prescribed value. This makes it unnecessary to provide the overspeed protector.

Abstract: In a control system for a gas turbine aero engine, the control system (ECU) is configured as a dual control system comprising two channels, Ch-A and Ch-B. Ch-A has two CPUs which conduct calculations separately based on the sensor outputs and one of the CPUs compares the results and if they coincide, the CPU sends the result of the other CPU to the FCU. If not, one of the CPUs determines that an abnormality arises in Ch-A and sends a result to Ch-B. Ch-B is constituted as a standby channel having only one CPU whose operation is monitored by a simple watchdog timer circuit. This enhances CPU failure detection with a relatively simple configuration, and eliminates the need for provision of an overspeed protector.

Abstract: Fuel flow and nozzle area are controlled by a multi-variable control. A requested fan speed is compared with measured fan speed, producing an error signal which is translated in a proportional-integral inner control loop into a requested compressor pressure signal that represents an acceptable rate of change in compressor pressure for difference between requested and measured fan speed. The error signal is compared with measured compressor pressure; the difference being used in a multi-variable control to adjust fuel flow and turbine exhaust area to achieve the requested compressor pressure.

Abstract: In an aircraft gas turbine engine having a variable area exhaust, gas turbine compressor operating conditions are sensed to determine a sub-idle condition or a rotating stall. The exhaust area is increased to a maximum when a sub-idle condition is present. If a condition associated with a rotation stall is sensed, fuel flow is decremented but not below a minimum flow. When the rotating stall ends, fuel flow is restored to the normal level and then the engine reaches stabilized operating conditions, the nozzle area is restored at a scheduled rate.

Abstract: A method and system are provided to bias a control subsystem of a gas turbine engine having a fan and compressor. The method includes the steps of measuring an operating parameter of the engine and differentiating this parameter over time to obtain a derivative thereof. A bias signal is generated in a predetermined bias schedule in response to the parameter derivative, and provided to the control subsystem for biasing the subsystem. The bias signal has a zero value for values of the parameter derivative from zero to a first value thereof at a first time. The bias signal has a maximum value for values of the parameter derivative between second and third values thereof corresponding with second and third times. And, the bias signal returns to a value of zero after a fourth time greater than the third time.

Abstract: A gas turbine engine control for an engine which experiences airflow distortion at the engine inlet face plane uses a static pressure measurement upstream of the face plane along with a corrected rotor speed to generate a signal indicative of the average total pressure at the engine face plane. This signal is combined with a total pressure signal from elsewhere in the engine to generate a pressure ratio signal which is compared to the scheduled pressure ratio for the current operating conditions. Control logic then adjusts either the fuel flow rate to the burners or the area of the exhaust nozzle in response to the difference between these pressure ratios.

Abstract: This control serves to optimize thrust during steady state and transient operation modes of a turbofan engine of the mixed flow type by adjusting or trimming the exhaust nozzle area as a function of fan pressure ratio and fan rotor speed and by adjusting or trimming the core engine fuel flow as a function of fan rotor speed and/or turbine inlet temperature. The control serves to enhance stability by assuring airflow in the engine and its inlet is within a given value avoiding inlet buzz and high distortion to the engine and avoiding even transient operation in conditions that might cause compressor flow instability or stall. Fuel flow is adjusted or trimmed as a function of fan rotor speed or turbine inlet temperature limits depending on which is calling for the least amount of fuel.

Abstract: A method and apparatus for optimally controlling a gas turbine engine utilizes feedback signals each of which is a function of a plurality of output variables. Control signals are generated and transmitted to actuators which vary engine control variables to provide a desired level of engine performance. Signals representative of rated values of a plurality of engine output variables for the selected level of engine performance are generated and are compared with signals representative of actual values of the corresponding output variables to produce difference signals. One or more of the difference signals may also be integrated. The difference signals may also be weighted relative to each other as a function of ambient conditions and/or the selected level of engine performance. A plurality of the difference signals are then utilized to generate an individual feedback signal for each of the control variables. The feedback signals are tailored to modify the corresponding control variables.

Abstract: An integrated control system for a gas turbine engine of the turbofan type receives signals from a plurality of engine sensors and from the engine operator and generates control signals therefrom. A first control signal regulates the fan exhaust nozzle area in order to control inlet throat Mach number to maintain a low level of engine noise. Additional control signals regulate fuel flow to control engine thrust and fan pitch to control fan speed. A plurality of schedules are utilized to maintain a predetermined relationship between the controlled parameters and a number of fixed and calculated limits can override the control signals to prevent unsatisfactory engine performance.

Abstract: A coordinated fan pitch, fuel flow and fan exhaust nozzle area control for a gas turbine powered aircraft propulsor of the bypass duct, variable pitch and exhaust nozzle configuration serves to effectuate reverse pitch change through feather, by minimizing forward thrust excursion and shaft torque to obtain rapid reverse thrust response.

Abstract: A control for a variable pitch fan propulsor driven by a turbine type of power plant which fan is mounted in an engine bypass duct having a variable exit nozzle. The control serves to coordinate the control of fuel flow to the engine, the area of the fan exit nozzle, and the pitch of the fan blades by biasing the power lever position signal with Flight Mach No. An additional feature is the inclusion of fan surge control derived from signals of flight Mach No. and corrected free turbine speed.