Performance Evaluation on the In-Cylinder Heat Transfer of a Reciprocating Compressor using CO2 as a Working Fluid

The aim of this current work is to investigate the effects of operating parameters on heat transfer characteristics between gas and in-cylinder solid surfaces in a reciprocating compressor. A numerical model has been implemented in MATLAB based on mass balance, the first law of thermodynamics, and NIST REFPROP database for gas properties and thermodynamic relationships. The impacts of key parameters such as rotational speed, suction temperature, pressure ratio and suction pressure are particularly evaluated on heat transfer coefficient (HTC), heat flux (HF) and gas temperature. Results demonstrate that HTC increases markedly with the increase of rotational speed, pressure ratio and suction pressure, and decreases slightly with the increase of suction temperature; the instantaneous HF strengthens significantly with the increase of rotational speed, pressure ratio and suction pressure, whereas the mean HF magnitude transferred from gas to the wall decreases with the increase of rotational speed; the maximum gas temperature is more sensitive to suction temperature and pressure ratio.