Modeling a Reciprocating Compressor With Low-GWP Refrigerants

Replacing existing refrigerants with low-global warming potential (GWP) refrigerants in air conditioning and refrigeration systems can significantly reduce the negative impacts on global warming and ozone layer depletion. The compressor, the heart of the vapor-compression refrigeration cycle, has traditionally been designed for higher-GWP refrigerants. However, compressors must be able to operate efficiently on newer, lower-GWP refrigerants. Computational fluid dynamics (CFD) can be used to model the refrigerant flow through the compressor to determine the efficiency, operation temperatures, and valve dynamics.

In this webinar, we employ CONVERGE CFD software’s cut-cell-based autonomous meshing methodology to simulate a reciprocating compressor with an existing refrigerant (R-404a) and a lower-GWP refrigerant (R-449a). We demonstrate how to easily capture the complex moving geometries of the piston and reed valve, and how to resolve the pressure fluctuations in the suction and discharge mufflers. The results of the cylinder pressure, valve lift, and temperatures are validated against experimental data measured for both refrigerants across a range of operating conditions.