Heat transfer characteristics and heat exchanger performances for R407C using herringbone heat transfer tube

摘要

The new advanced heat transfer tube called, "Herringbone Heat Transfer Tube", having a unique inner surface geometry, have been experimentally investigated with the aim to enhance the heat transfer and to improve the heat exchanger performance for R407C. Experimental examinations have been done to obtain the air-cooled heat transfer coefficient and pressure drop for R407C flowing inside the horizontal herringbone tube, and the data have been compared with those for the existing inner grooved tubeBoth the air-cooled heat exchanger performances using the herringbone tube and the inner grooved tube have been compared as the practical examination for designing the heat exchanger using the herringbone tube. As the results of the experiments, the heattransfer coefficients for the herringbone tube have been verified to be much superior to the existing inner grooved tube, but the significant increase in heat transfer has been accompli shed with an increase in pressure drop. The practical comparison ofthe heat exchanger performance showed that the evaporator performance have been improved only at the relatively high refrigerant flow rate, while the condenser performance using the herringbone tube have been better than that using the inner grooved tubefor all the refrigerant flow rates.