An experimentally validated model for microchannel condensers with separation circuitry

Abstract

The experimental study on a microchannel condenser with the separation circuitry (or separation condenser) was conducted in the past by the same authors. The separation condenser has an inlet in the middle of the height, and vapor separates from the liquid in the second header after condensation in the 1st pass. This paper presents a condenser model that incorporates a mechanistic model developed to predict the phase separation efficiency in the second header. The 1-D finite-volume method is used. The condenser model is validated by condenser testing results using R134a. The mass flux through the first pass is in the range of 145–330 kg m−2 s−1. The difference between measurement and modeling result is ±5% for capacity and ±15% for pressure drop. The model reveals that other than the in-header fluid dynamics for the two-phase flow, the downstream flow resistance (a function of the air velocity) also influences the separation results in the second header, based on the equal pressure drops in the upper path and lower path. The model could be used for the design optimization for separation condensers, which will be presented in another study.