In the present study, a zero-dimensional numerical method is developed based upon the crank angle to investigate reciprocating natural gas compressor with valve faults. This model aims to take piston movement, valve dynamic, and mass flow rate through valve and orifice equations into account. To this end, three control volumes including compressor cylinder, suction, and discharge chambers with equivalent mass and energy equations are investigated. Valve faults, which include valve plate failure, wearing on the plate and its seat, and springs deterioration, lead to valve leakage. For valve leakage simulation, a hole in the valve plate is considered. Simulated results validate the previous experimental results for normal operating compressor with healthy valves. The predicted results show that the suction and discharge valve failures decrease compressor mass flow rate and increase discharge gas temperature. Furthermore, effect of the suction valve fault is more serious than that of the discharge valve fault. In addition, valve fault can be detected by monitoring the gas temperature of the suction and discharge chambers.

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