HEAT TRANSFER PIPE FOR HEAT EXCHANGER, HEAT EXCHANGER, REFRIGERATION CYCLE APPARATUS, AND AIR-CONDITIONING APPARATUS

摘要

A heat transfer pipe for a heat exchanger including high threads and low threads that are lower than the high threads. The high threads and the low threads are provided at respective prescribed heights in a helical manner in a pipe axial direction on an inner surface of a pipe, the high threads are formed with 11 to 19 threads, the low threads are formed with 3 to 6 threads between each pair of the high threads, the high threads before expansion of the pipe each have a trapezoidal shape in cross-section so that a crest before the expansion of the pipe is flat, and a ratio W1/D of a tip width W1 of the crest portion after the expansion of the pipe to an outer diameter of the heat transfer pipe is 0.011 to 0.040. Further, the high threads before the expansion of the pipe are higher by 0.04 mm or more than the low threads.