Twisted tube heat exchanger and method for manufacturing twisted tube heat exchanger

摘要

A twisted tube heat exchanger which can prevent corrosion of a brazed joined part of water tubing is provided. A twisted tube heat exchanger 1, comprises: water tubing 3 which is made of phosphorus deoxidized copper, and which is provided with plural rows of crests and valley bottoms on the circumference thereof in a continuous and spiral form for each row; refrigerant tubing 5 which is spirally wound up and secured along the shape of the crest and valley bottom on the circumference of the water tubing 3; and joint tubing 4 which is made of phosphorus deoxidized copper, and which is connected to an end of the water tubing 3, wherein a joined part between the water tubing 3 and the joint tubing 4 is brazed with a brazing material 2 of phosphorus copper filler metal containing 4.0 to 8.0 weight% of tin, and 6.8 to 8.0 weight% of phosphorus, but containing no silver.