Evaluation of microchannel condenser characteristics by numerical simulation

• A microchannel condenser model is developed for heat exchanger design.
• Non-uniform air flow, fin conduction and pressure balance are taken into account.
• Well match with 1-slab and 2-slab lab test data.
• Present optimization results for 1-slab and 2-slab microchannel condenser.

This paper presents the development of a finite-volume-based numerical condenser model that considers important factors such as non-uniform air temperature and velocity at the front, fin conduction, refrigerant-side maldistribution caused by pressure balance between tubes, and air-side distribution for multislabs. Air-side and refrigerant-side microscale heat transfer and pressure drop correlations are carefully compared. The model results match well with lab test results for one-slab and two-slab microchannel heat exchangers on heat transfer and pressure drop. Several simulations are conducted to determine the impact of return air temperature, tube wall temperature, and non-uniform refrigerant flow rate. In addition, optimization results are analyzed by changing the number of flat tubes in each pass for both types of heat exchangers.