| 摘要 |
The present invention discloses a double pipe heat exchanger with a spiral rib and a manufacturing method thereof. The present invention comprises: an outer pipe, made of a metal, forming a first end, a second end, a central part between the first end and the second end, a first path formed for connecting the first end and the second end to each other, and a plurality of spiral ribs along a longitudinal direction on the inner circumference of the first passageway; and an inner pipe inserted into the outer pipe to making the first end and the second end protruding out of the outer pipe. Ribs eliminated sections, where the spiral ribs are eliminated, are formed on the first end, the second end of the outer pipe and the inner circumference of the outer pipe adjacent to the first end and the second end of the outer pipe. Each of the ribs eliminated sections has a pipe expanding part whose diameter is larger than that of a center part, and a pipe contracting part whose diameter is less than that of the center part. Penetrated holes are formed on the pipe expanding part for being connected to the first passageway, and the pipe contracting part is joined with the outer circumferential surface of the inner pipe by brazing to close the first passageway. The present invention can braze the outer pipe and the inner pipe with a simple structure by using the contracted pipe of the outer pipe, so can enhance the productivity and the reliability by prevention poor adhesion. Additionally, the present invention forms the spiral ribs on the inner circumference of the outer pipe and the inner pipe by extrusion, so can increase a heating surface and enhance the heat exchange efficiency by increasing a flow length of the fluid. Additionally, the present invention enlarges a portion to which a connecting pipe is connected for inducing and discharging the fluid and enlarges the diameter, so can smooth the flow of the fluid and enhance the heat exchange efficiency. |
