PERFORMANCE ENHANCEMENT OF MOBILE AIR CONDITIONING SYSTEM USING VARIABLE GEOMETRY MICRO CHANNEL HEAT EXCHANGER (MCHX)

Due to stiff competition among the Original Equipment Manufacturer (OEM’s), the Comfort, Fuel efficiency & Safety are the key factors that drive the vehicle business; in that context A/c plays an important part for the comfort of the passengers. However, condenser plays a pivotal role in Power train cooling system & Air conditioning system. Therefore it is a big challenge for the automotive engineer to propose an innovative design that can improve the thermal performance of Condenser without not compromise the package size. The objective of this paper is to further enhance the Condenser performance by using variable geometry on both port & tube control volume and also optimizing the fin parameters for various tube profiles. Selection of refrigerant side pressure drop correlation based on comparison of analytical results with the experimental data (component calorimeter) for the fixed geometry. The mathematical calculation is derived to address two phase density using suitable pressure drop correlations and its effects on refrigerant side heat transfer. Since the effect of air side heat transfer co-efficient plays an important role in overall heat transfer coefficient, the fin optimisation using mathematical calculation and CFD results were carried out. Finally the optimised fin parameters are considered to find out the effect of variable geometry (tube & port) on the overall heat transfer coefficient using CFD & Bench test results.