Experimental Investigation of Heat Transfer Rates and Pressure Drops through Compact Heat Exchangers

This paper presents pressure drops and heat transfer rates for compact heat exchangers, where the heat exchangers are angled 90°, 60°, 30° and 10° relative to the incoming airflow. The investigation is based on two heat exchangers with different thicknesses, 19mm and 52mm. The experiments were performed for five airflow rates and five coolant flow rates, where the inlet temperature of the coolant was defined to two temperatures; ambient temperature and 90°C. The test set-up is defined as having a constant cross-section area for 90°, 60° and 30° angles, resulting in a larger core area and a lower airspeed through the core, for a more inclined heat exchanger. The investigation showed that the more inclined heat exchangers resulted in lower static pressure drops and at the same time achieved higher heat transfer rates, for a specific mass airflow rate.