A microchannel heat exchanger was numerically analyzed using the finite volume method. The air and refrigerant-side heat transfer coefficients and pressure drops were calculated using the existing correlations that were developed for microchannel heat exchangers. To verify the present model, performance tests of the microchannel heat exchanger were conducted at various test conditions with R134a. The present model yielded a good correlation with the measured heat transfer rate, demonstrating a mean deviation of 6.8%. The performance of the microchannel evaporator for CO2 systems can be improved by varying the refrigerant flow rate to each slab and changing fin space to increase the two-phase region in the microchannel. Based on the comparison of the performance of the microchannel heat exchanger with that of the fin-tube heat exchanger designed for CO2 systems, it was proposed that the arrangement of the slabs and inlet air velocity in the microchannel heat exchanger need to be optimized by considering heat exchanger size, air outlet conditions and required capacity.
|Number of pages||7|
|Journal||Applied Thermal Engineering|
|Publication status||Published - 2007 Jun|
- Microchannel heat exchanger
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Industrial and Manufacturing Engineering