초록 ▼

A method and apparatus for predicting the onset of stall in an axial flow compressor and stabilizing stall so as to achieve the maximum pressure rise to the combustor. Stall in an axial flow compressor is predicted by obtaining pressure or axial velocity measurements at a plurality of circumferentia

A method and apparatus for predicting the onset of stall in an axial flow compressor and stabilizing stall so as to achieve the maximum pressure rise to the combustor. Stall in an axial flow compressor is predicted by obtaining pressure or axial velocity measurements at a plurality of circumferential angles around a compressor stage, fourier transforming the measurements with respect to the circumferential angles to obtain a time history of the zeroth, first and higher modes, and determining amplitude gain at twice the rotor frequency of the transfer function from the product of the zeroth and first modes to the first mode, with an increase in amplitude gain depicting a right skewed compressor going into stall and a decrease in amplitude gain depicting a left skewed compressor going into stall. Rotating stall and surge in the compressor is stabilized so that the pressure rise to the combustor can be maximized by creating an oscillatory motion of the pressure and feeding said oscillatory motion back to vary the set point of an extremum seeking controller, wherein an internal rotating stall and surge feedback loop in said controller that stabilizes said compressor is closed and wherein an outer extremum seeking loop in said controller which maximizes the pressure rise is closed.

대표청구항 ▼

[ What is claimed is:] [1.] A method for predicting stall in an axial flow compressor, comprising the steps of:(a) obtaining pressure or axial velocity measurements as a function of time at a plurality of circumferential angles around a compressor stage having a rotor that rotates at a rotor frequen

[ What is claimed is:] [1.] A method for predicting stall in an axial flow compressor, comprising the steps of:(a) obtaining pressure or axial velocity measurements as a function of time at a plurality of circumferential angles around a compressor stage having a rotor that rotates at a rotor frequency;(b) discrete fourier transforming said measurements with respect to said circumferential angles to obtain zeroth, first and higher modes as a function of time; and(c) determining amplitude gain, at twice the rotor frequency, of a transfer function from the product of the zeroth and first modes to the first mode, with an increase in amplitude gain depicting a right skewed compressor going into stall and a decrease in amplitude gain depicting a left skewed compressor going into stall.