surge

Phenomenon 1: The current decreases and fluctuates frequently, while the outlet air pressure also drops and fluctuates. 2 The fan produces abnormal noise at high levels, experiences significant vibration, its casing temperature rises, and the surge vibrations of the supply and exhaust fans cause fluctuations in the negative pressure inside the furnace, leading to unstable combustion. Baidu’s, I don’t really understand it:)

Causes of surge: A sudden and instantaneous drop in inlet pressure or flow rate? When it falls below the minimum allowable operating point? The gas inside the compressor experiences changes in flow rate, which leads to severe rotational separation; this results in abrupt stall, characterized by a large deviation in the flow direction of the gas at the inlet of the blade channels and at the inlet angle of the impeller. The impeller is unable to effectively increase the pressure of the gas, causing the outlet pressure to drop. However, the system pressure does not decrease instantly; as a result, gas flows back from the system into the compressor. When the system pressure drops below the outlet pressure of the compressor, gas flows back into the system again. Repeating this process leads to periodic axial, low-frequency, high-amplitude airflow oscillations within the unit and the piping system. Phenomenon: Significant fluctuations in the pressure of the gas exiting the system, and unstable motor current (the turbine shows fluctuations in speed)