Heat Transfer Analysis of Conventional Round Tube and Microchannel Condensers in Automotive Air Conditioning System

Abstract

In this paper, an experimental analysis of conventional air cooled round tube and microchannel condensers in an automotive air conditioning cycle in term of heat transfer coefficient and energy is presented. The analysis was carried out in a test unit of automotive air conditioning system works with R134a. The conventional round tube plate fin condenser, and cycle were examined first. After that the conventional condenser is replaced by a parallel flow multi-louvered fin microchannel condenser with 0.1 mm hydraulic diameter, and the same experiments in same conditions have been re-implemented. The performance of two condenser and cycles were tested in terms of ambient temperature, which it was varied from 40^oC to 65^oC. Besides, the indoor temperature and load has been set to 23^oC and 2200 W respectively. It was found that replacing the round tube conventional condenser with a microchannel is useful and can enhances the total cycle performance. Because, the microchannel condenser has 224 % and 77 % higher refrigerant side and air side heat transfer coefficient than the conventional. So that, the COP, in case of using the microchannel condenser, was found to be 20 % higher than the conventional. In addition, the microchannel condenser 50 % smaller volume than the conventional. Therefore, it provides more empty space in the car engine container to be occupied with other components or to be removed.

Keywords: Automotive air conditioning, Condenser, Microchannel, Heat transfer, Energy