Mathematical Modeling and Simulation of a Two-stage Reciprocating Air Compressor Considering Heat Transfer Effect

Fault prognostics of an air compressor is a challenging issue for condition-based maintenance of a railway vehicle. In this paper, we propose a mathematical model of a two-stage reciprocating air compressor to obtain normal and abnormal data for the pressure and temperature for various parts of the air compressor. The mathematical model includes kinematic equations of crank mechanism, thermodynamic equations of cylinders, valve flow equations, and heat transfer equations of cylinder blocks. Especially, heat transfer effects at cylinder blocks are simulated for the cases with and without heat transfer. Simulation results show that the mathematical model is valid and heat transfer effect at cylinder blocks is minimal to cylinder pressure but affects cylinder temperature significantly.