Diagnosis method to identify diaphragm state of diaphragm compressors for hydrogen refueling stations based on dynamic oil pressure

Frequent diaphragm rupture of diaphragm compressors is a severe issue in hydrogen refueling stations, generally occurring when the diaphragm collides violently with the oil plate. The oil pressure exhibits distinct properties in different working conditions, due to the oil-gas cooperative working characteristics of diaphragm compressors. This paper proposes a diagnosis method to identify the state of the diaphragm, separating the maximum and minimum oil pressures from the complex working parameters as characteristic signals. Especially, this method can forewarn the collision. The precise reason for the failure can also be identified combined with the overflowed oil flow. Several common fault types were reproduced and evaluated to verify this method's reliability. Experimental results confirmed that this method could accurately identify the diaphragm states, and can issue a collision warning 25 min in advance for a 45 MPa diaphragm compressor even in accelerated tests.