Valves, leakage, testing & evaluation
Leakage through valves can significantly reduce the volumetric and isentropic efficiencies of compressors. Despite its importance for compressor design, the dimensional characterization of leakage gaps is not a trivial task. In this paper, we present a combined experimental-numerical method to estimate leakage gap of compressor valves. Measurements of leakage were carried out via the constant volume method, which is widely employed in the analysis of gas flow through microchannels. Additionally, numerical predictions were obtained with a one-dimensional flow model, taking into account viscous friction, slip at the walls, and gas compressibility. The leakage gap in the simulation model is adjusted so that predictions match the experimental results of leakage for different pressure differences. The procedure is applied for the analysis of three valve designs of refrigeration compressors.