Thermodynamic analysis of natural gas reciprocating compressors based on real and ideal gas models

•Reciprocating compressors are simulated thermodynamically.•Real gas is modeled using AGA8 equation of state and thermodynamic relations.•The in-cylinder thermodynamics properties have been calculated numerically.•A good agreement with previous measured values is obtained.•The effects of important parameters investigated on the performance compressors.

The accurate modelling and investigating effects of various parameters of the reciprocating compressors are important subjects. In this work, based on first law of thermodynamics, conversation of mass and real and ideal gas assumptions, a theoretical analysis has been constructed to simulate natural gas reciprocating compressors. For computing the thermodynamic properties of natural gas based on real gas model, the AGA8 equation of state has been used. Numerical results validated with previous measured values and showed a good agreement. The effects of important parameters such as: angular speed, clearance and pressure ratio have been studied on the performance of the compressors. The results reveal the in-control volume temperature for ideal gas is more than real gas model but the mass flow rate and work for real gas is higher than ideal gas model. On the other hand, the indicated work that required for compression is greater for ideal gas model.