Numerical simulation of the flow through a compressor-valve model using an immersed-boundary method

Abstract

Hermetic reciprocating compressors are widely used in small- and medium-size refrigeration systems based on the vapor-compression cycle. One of the main parts of this type of compressor is the automatic valve system used to control the suction and discharge processes. As the suction and discharge losses represent a large amount of the total thermodynamic losses (47%), a small improvement in the suction and discharge processes can produce expressive increases in the thermodynamic efficiency of the compressor. In this work, a new numerical methodology is applied to solve the flow through reed-type valves. The numerical results were experimentally validated through the pressure distribution acting on the frontal disk of a radial diffuser, which is a geometry usually used to model this type of valve. The numerical results for the velocity and pressure fields were comprehensively explored during the opening and closing movement imposed to the reed. The good quality of these results show that the numerical methodology is very promising in terms of solving the flow in the actual dynamics of reed-type valves.