Experimental and numerical investigation of an air-to-water heat pipe-based heat exchanger

The objectives of the reported experimental investigation were to analyse the effect of multiple air passes at different air inlet temperatures (100-250 °C) and air mass flow rates (0.05-0.14 kg/s) on the thermal performance of the heat exchanger unit including the heat pipes. The results were compared with a CFD model that assumed the heat pipes were solid rods with a constant conductivity. The conductivity of the pipes was extracted from modifications of correlations available in the literature based around the theory of Thermal Resistance. The results proved to be very accurate within 10% of the experimental values.