High Performance Evaporator Development

This paper is an introduction to the design, development and heat transfer performance of a new drawn-cup plate evaporator for the refrigerant cycle of automotive air conditioning systems. This evaporator is characterized by the tank section at one side alone and U-turn refrigerant path in each tube. This system has reduced dead space and has superior overall heat transfer coefficient. Therefore, we expected that its potential performance would be much higher than any other conventional type. But, while developing it, we encountered some serious structural problems which affected the flow of the refrigerant and heat transfer in the U-turn sections. We isolated the causes of the performance degradation by analizing the refrigerant flow behavior in these sections. With this type of evaporator we finally achieved our target of 15% improved performance compared with the serpentine tube evaporator.