Method of detecting and controlling stall in an axial fan

摘要

A method of detecting stall in an axial fan through acoustical measurements in air the air flow, includes measuring the sound emanating from the flow adjacent the fan, preparing a visual representation of the sound, comparing the visual representation with a library of fixed visual representations derived from a plurality of tests representative of the performance of the fan under a range of operating parameters, selecting the fixed visual representation most closely matching the visual representation of the said sound, and deriving a control signal from the selected fixed visual representation. The visual representations are formed by a symmetrised dot pattern (SDP) technique.

主权项

1. A method of detecting and controlling stall in an axial fan through acoustical measurements in the air flow, comprising:
measuring the sound emanating from the flow; preparing a visual representation of the sound; comparing the visual representation with a library of fixed visual representations, the library of fixed visual representations derived from a plurality of tests representative of the performance of the fan under a range of operating parameters, wherein the library of fixed visual representations comprises a plurality of visual representations each depicting only one of: normal flow conditions, incipient stall conditions, and stall conditions; selecting the fixed visual representation most closely matching the visual representation of the sound; determining if the fan is approaching incipient stall based on the selected visual representation; and generating a feedback control signal to control the operation and speed of the fan when the fan is determined to be approaching incipient stall.