Heat exchanger and air conditioner using the same

Abstract

A heat exchanger in which, even if an aluminum material is used for fins and heat transfer tubes of the heat exchanger, pressure loss in the heat transfer tubes does not increase and the heat exchanger has heat transfer performance the same as or better than that of heat exchangers using copper tubes. A heat exchanger is provided with fins (10) consisting of an aluminum base material having low deformation resistance, and also with heat transfer tubes (20) consisting of an aluminum based material which has higher deformation resistance, having grooves (21) in the inner surfaces of the heat transfer tubes (20), and fixed by causing the heat transfer tubes (20) to penetrate through the fins (10). The direction (b) of the axis of the inner surface of each heat transfer tube (20) and the direction (a) of the grooves (21) formed in the inner surface of the heat transfer tube (20) are set substantially parallel to each other. In this case, the angle of the direction of the grooves (21) relative to the direction (b) of the axis of the inner surface of the heat transfer tube (20) is from 0 DEG C to 2 DEG C. The depth of the grooves (21) in each heat transfer tube (20) after the tube (20) is expanded in diameter is from 0.2 mm to 0.3 mm, and the width of the crest (22) of the ridge between adjacent grooves (21) is from 0.08 mm to 0.18 mm. The number of grooves (21) in each heat transfer tube (20) is from 40 to 60, and the angle of the crest of the ridge between adjacent grooves (21) is from 5 DEG C to 20 DEG C.

Description

technical field [0001] The present invention relates to a heat exchanger incorporating a heat transfer tube with inner surface grooves, and an air conditioner using the heat exchanger. Background technique [0002] Conventionally, in heat exchangers such as air conditioners, heat transfer tubes with internal grooves are generally arranged at regular intervals, and refrigerant flows inside them. In addition, the direction of the tube axis on the inner surface of the tube forms a certain angle (7°-30°) with the direction in which the grooves extend, and a plurality of grooves are processed to form peaks, and the fluid flowing in the tube undergoes a phase change (condensation, evaporation). In such a phase change, the heat transfer tube achieves performance improvement (such as Refer to Patent Document 1). [0003] Patent Document 1: Japanese Unexamined Patent Publication No. 60-142195 (page 2, figure 1 ) [0004] Conventional heat transfer tubes including the heat transfe...

AI Technical Summary

Problems solved by technology

However, when the tube is expanded to fix the heat transfer tube to the fins, the peak shape of the inner surface collapses, and the heat transfer performance equal to or higher than that of the copper tube cannot be obtained.

[0005] In addition, since aluminum is weaker than copper, it is necessary to increase the thickness of the groove bottom of the heat transfer tube, which increases the pressure loss inside the heat transfer tube.

Images