Thermal Design Study of A High Performance Evaporator for the Automotive Air Conditioner

It has been well known that the new R-134a refrigerant system requires more efficient evaporator with better performance to obtain equivalent or better cooling capacity and system performance than the one of R-12 using automotive air-conditioning system due to its inherent thermo-physical properties. Various new efficient and compact type evaporators, especially drawn cup plate type evaporators, have been proposed since R-134a is being enforced in automotive air-conditioning system for environmental conservation purpose. But to now few investigations have been done regarding the thermal and hydrodynamic characteristics of these type evaporators. In the present study, the thermal and hydrodynamic analysis has been carried out for the U-flow (or so called “single tank compact drawn type”) plate type evaporator for automotive air-conditioning system using R-134a refrigerant. From the present study results, it became possible to predict the cooling capacity, downstream air temperature as well as the pressure drop of both air and refrigerant for this evaporator.