Comparative analysis of the performance of an offset-strip fin heat exchanger as evaporator in a refrigeration system with R22 and R417A.

Offset Strip Fins are often employed to build plate and fins heat exchangers used as condensers and evaporators in refrigeration systems, but the information available regarding them is not too extensive. Therefore, an experimental analysis of a refrigeration system which uses this kind of heat exchanger as evaporator was performed by using R417A and R22 as refrigerants. The heat transfer rate and the overall heat transfer coefficient in the heat exchanger were evaluated as a function of working conditions of the refrigeration system. Moreover, the heat transfer coefficient in the refrigerant side was obtained from the experimental overall heat transfer coefficient and the convection heat transfer coefficient in the secondary fluid side, which was previously determined in a set of tests performed by pumping water through both heat exchanger sides and applying a modification of the original Wilson plot technique.