reciprocating compressors, heat transfer, CFD
How to deal with the heat transfer inside compressors is one of the main challenges on its design nowadays. The heating of the gas entering the compressors decreases its density reducing directly the mass flow and compressor efficiency, so should be avoid. To study this topic it was developed a full three-dimensional model of the gas and the solid parts inside a compressor. Prescribed steady state mass flow rate is imposed at suction and discharge tubes and heat sources due electrical and mechanical inefficiencies of the compressor are imposed. The portion of the suction and cavity gas are separated from the portion of the discharge gas and an isentropic compression from the suction muffler outlet temperature is assumed to define the temperature of the gas flowing through the discharge port. The main advantage of this approach is the directly calculation of the heat transfer coefficients from the solid parts to the fluid, however with a high computational cost. Comparison with experimental data shows good agreement is some parts, but some disagreement in order, probably due poor mesh resolution affecting negatively the heat exchange prediction and also due the non-consideration of the oil flowing inside the compressor, which are topics for future investigations.