Numerical and experimental study on thermal characteristics of louvered fin microchannel air preheaters

Abstract

Microchannel heat exchangers have been gradually getting importance in industrial applications due to offering outstanding benefits. The current study has focused on the development of a numerical model to predict the thermal performance of the microchannel air preheaters (MCPH) for HVAC systems. An experimental study has been performed to validate the numerical model results. A louvered fin multiport microchannel heat exchanger has been employed as an air preheater in the experiments. The proposed model has been developed based on the segment-by-segment approach and calculated the outlet temperature and heat capacity of the MCPH. Different air velocities at the frontal face and varying mass flow rates in passes of the MCPH have been taken into consideration in the model. It has been concluded from experimental data that the model predicts the outlet temperature with an average absolute deviation within ±2% for all investigated test conditions. The proposed model shows high accuracy with respect to temperature calculation. Another conclusion is that the non-uniform air velocity approach improves the precision of the proposed model. The heat capacity predictions with the uniform air velocity approach indicate higher deviations than the non-uniform air velocity approach.