Simplified modeling analysis of mass flow characteristics in electronic expansion valve

A mass flow correlation was presented to predict mass flow coefficient in an EEV (electronic expansion valve) based on extensive experimental data for R22, R410A and R407c. Bernoulli equation for short orifice valve is modified by introducing expansion factor and the modified equation can well depict the behavior of fluid through EXV under linear, nonlinear and choked regions. Experimental analysis shows that the mass flow coefficient is dominantly influenced by EEV opening and subcooling value. Therefore, only the two parameters (EEV opening and subcooling) are used to develop the mass flow coefficient correlation. The flow coefficient predicted by polynomial fit in this paper shows a good agreement with experimental data for three datasets of R22, R410A and R407c and the relative errors are within 5% for 98% of experimental data.