Advanced development of air-conditioning and refrigeration equipment using alternative refrigerant

摘要

This paper describes progressive reseach and development of air-conditioning and refrigerationequipments using alternative refrigerants. The focus in the present study is directed to development ofthe air-cooled heat exchanger installed into the air-conditioning machine. The heat transfercharacteristics for the alternative refrigerants, R407C and R410A, are examined experimentally, andthe research subjects to modify the air-cooled heat exchanger using each alternative refrigerant areclarified through the experimental results. With respect to R407C, the unique inner grooved tube"Herringbone heat transfer tube" is developed to recover the degradation of heat transfer coefficientsof R407C. For R410A, the lower pressure drop for R410A than that for R22 provides the superiorheat exchanger performance, while the high pressure of this refrigerant requires the enlargement ofthe tube thickness.