The condensation mannered null heat transfer inside of pipe

摘要

PROBLEM TO BE SOLVED: To provide a condensation accelerating heat exchanger tube, and a method for condensing non-eutectic mixed refrigerant using it, in which lowering of condensation heat transfer rate in the tube is suppressed as much as possible when the non-eutectic mixed refrigerant flows through the tube at a low refrigerant mass speed of 150 kg/(m2.s) or less.;SOLUTION: In the inner surface of a tube, first grooves 10 having an angle of torsion of 20-40° with respect to the tube axis and a depth of 0.20-0.35 mm and second grooves having an angle of torsion in the range of ±5° with respect to that of the first grooves 10 and a depth in the range of ±5 mm with respect to that of the first grooves 10 are made to extend continuously in the direction of tube axis while intersecting thus forming a large number of quadrangular prismoidal protrusions 14, each having a height of 0.15-0.40 mm and four bottom sides shorter than the widths of first and second grooves 10 and 12, in zigzag independently from each other.;COPYRIGHT: (C)2002,JPO