Detection device, rotary machine, and detection method

A detection device for detecting a passage timing of a turbine blade, the detection device comprising:

• a sensor including a magnet and a coil that is disposed at a position subject to magnetic flux generated by the magnet, the sensor being configured to detect an induced electromotive force based on a change in the magnetic flux accompanying passage of the turbine blade;
• an analyzer configured to detect the passage timing of the turbine blade on the basis of an integrated signal obtained by integrating a signal based on the induced electromotive force;
• an integrator disposed between the coil and the analyzer and configured to integrate the signal based on the induced electromotive force and output the integrated signal;
• and
• a high-pass filter disposed on an output side of the integrator and configured to allow only a high-frequency component of the integrated signal to pass,
• wherein the analyzer detects the passage timing of the turbine blade based on the integrated signal that has passed through the high-pass filter.

A detection method for detecting a passage timing of a turbine blade, comprising:

• a step of detecting, by a sensor including a magnet and a coil disposed at a position subject to magnetic flux generated by the magnet, an induced electromotive force based on a change in the magnetic flux accompanying passage of the turbine blade;
• and
• a step of detecting the passage timing of the turbine blade, on the basis of an integrated signal obtained by integrating a signal based on the induced electromotive force, by an analyzer,
• the integrated signal having a waveform with a peak value at a timing corresponding to the zero-crossing point of a vertical oscillation associated with the passage of the turbine blade in a waveform of the signal based on the induced electromotive force.

A detection method for detecting a passage timing of a turbine blade, the detection method comprising:

• a step of detecting, by a sensor including a magnet and a coil disposed at a position subject to magnetic flux generated by the magnet, an induced electromotive force based on a change in the magnetic flux accompanying passage of the turbine blade;
• a step of detecting the passage timing of the turbine blade, based on an integrated signal obtained by integrating a signal based on the induced electromotive force, by an analyzer;
• a step of acquiring a reference waveform of the integrated signal while rotating the turbine blade;
• a step of identifying, on the reference waveform, a passage time period in a detection range where an inclination of an axial end surface of a shroud portion of the turbine blade with respect to a circumferential direction is within a predetermined range, and identifying a fluctuation range of the integrated signal on the reference waveform during the passage time period;
• and
• a step of setting a threshold for detecting the passage timing within the fluctuation range.