Effect of Circuit Arrangement on the Performance of Plate Finned Tube Heat Exchangers Under Dehumidifying Conditions

Abstract

This study experimentally investigates the effect of circuitry on the performance of plate finned tube evaporators. Experiments were carried out with the heat exchangers having 1-circuit arrangements. A total of six circuitry were examined in this study, including two counter-cross, two parallel-cross, and two z-shape arrangements. The results showed that the counter-cross arrangement gives the best performance. However, heat conduction along the fins may offset the benefits of the counter-cross arrangement. In addition, the pressure drop of refrigerant-side increased with frontal velocities. Among the six 1-circuit arrangements, the parallel-cross flow circuit would produce a larger pressure drop than other arrangements. However, for G = 200 kg/m2·s and parallel flow, the pressure drops decrease with increase of the frontal velocity. The unusual characteristics are likely related to the flow pattern transition subjected to heat addition. The location of refrigerant inlet does not significantly affect the performance of heat exchangers.