Systems and methods for detecting shear of a rotating shaft are described herein. A first measurement and a second measurement of a rotational speed of the shaft are acquired. The first measurement is taken at a first location along the shaft and the second measurement taken at a second location along the shaft. The first location is axially-spaced from the second location. The first and second location are on opposite sides of an expected breakage point of the shaft. A first rate of change of the rotational speed is determined from the first measurement. A second rate of change is determined from the second measurement. Shear of the shaft is detected when the first rate of change is positive and the second rate of change is negative.

The present invention discloses a novel way of controlling a gas turbine engine using detected temperatures and detected turbine rotor speed. An operating system provides a series of operating modes for a gas turbine combustor through which fuel is staged to gradually increase engine power, yet harmful emissions, such as carbon monoxide, are kept within acceptable levels.

A control device that controls a fuel gas supply system that has: a compressor that supplies compressed fuel gas to a load apparatus; an inflow amount regulating means that regulates the amount of fuel gas that flows into the compressor; an anti-surge valve that is for returning to an inlet side of the compressor fuel gas that is discharged from the compressor; and an inlet pressure-regulating valve that regulates the pressure of fuel gas supplied toward the inflow amount regulating means. The control device includes: a main pressure-regulating unit that controls the inflow amount regulating means and the anti-surge valve using a first feedforward control value that is generated on the basis of the load of the load apparatus and of a first conversion process and using a feedback control value that is generated on the basis of the deviation between a set value and a measured value for the discharge pressure of the compressor; and an inlet pressure-regulating unit that controls the inlet pressure-regulating valve using a second feedforward control value that is generated on the basis of the load of the load apparatus and of a second conversion process.

A hydraulic lock apparatus includes a hydraulic actuator, a pressure storage device connected to the hydraulic actuator, and a control valve configured to actuate to a first position and a second position. The control valve fluidly isolates the pressure storage device from the hydraulic actuator when the control valve is in the first position. The control valve fluidly connects the pressure storage device to the hydraulic actuator when the control valve is in the second position.

There is described a shaft shear event detection method. The method comprises storing in memory a shaft oscillation signature determined as a function of known characteristics of the shaft and associated with a shaft shear event; monitoring a rotational speed of the shaft; detecting from the rotational speed an oscillation wave superimposed on the rotational speed by detecting a first period below a lower threshold and a second period above an upper threshold, and detecting a rate of occurrence of the first period and the second period, the oscillation wave having a wave modulation frequency corresponding to the rate of occurrence and a wave modulation amplitude; comparing the oscillation signature to the oscillation wave; and detecting the shaft shear event when the oscillation wave corresponds to the oscillation signature.

A dual trip manifold assembly (TMA) includes an isolation valve assembly having a first valve configured to receive a flow of fluid from a hydraulic system fluid supply. The first valve is configured to channel the flow of fluid to at least one hydraulic circuit. The isolation valve assembly also includes a second valve configured to receive the flow of fluid from the at least one hydraulic circuit of the at least two hydraulic circuits. The second valve is further configured to channel the fluid flow to a trip header and to receive the fluid flow from the trip header. The first valve and the second valve are synchronized to each other such that rotation of one of said first and second valves causes a substantially similar rotation in the other of said first and second valves header.

There is described a shaft shear event detection method. The method comprises obtaining a demodulated waveform of a shaft oscillation wave superimposed on a shaft rotational speed signal, comparing the amplitude to an amplitude threshold, detecting oscillation when the amplitude threshold is exceeded for a plurality of samples, and detecting a shaft shear when oscillation continues for a predetermined time limit.

There is described a shaft shear event detection method. The method comprises storing in memory a shaft oscillation signature determined as a function of known characteristics of the shaft and associated with a shaft shear event; monitoring a rotational speed of the shaft; detecting from the rotational speed an oscillation wave superimposed on the rotational speed, the oscillation wave having a wave modulation frequency and a wave modulation amplitude; comparing the oscillation signature to the oscillation wave; and detecting the shaft shear event when the oscillation wave corresponds to the oscillation signature.

A trip system for a steam turbine closes a trip-and-throttle valve and a control valve of a steam turbine in an emergency. The trip system includes: an emergency shut-off device that shuts off supply of control oil for the trip-and-throttle valve and the control valve to close the trip-and-throttle valve and the control valve; and a drain device that includes a plurality of solenoid valves connected in parallel and drains the control oil by opening the solenoid valves. The emergency shut-off device includes a cylinder, a piston that slides in the cylinder, a spring that applies biasing force to the piston, a plurality of piston valves provided to the piston, and a plurality of chambers formed by the piston valves.

The invention relates to an overspeed protection device of an aircraft engine.