| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a double-wall-tube heat exchanger capable of preventing crushing of a refrigerant flow path between inner and outer tubes even when a bent portion is formed, and simplifying its manufacturing work. <P>SOLUTION: This double-wall-tube heat exchanger includes an outer tube 2, and an inner tube 3 disposed in and spaced apart from the outer tube 2. A clearance between the outer tube 2 and the inner tube 3 and the interior of the inner tube 3 serve as respective refrigerant flow paths 4, 5. Both end portions of the inner tube 3 is projected outward with respect to both end portions of the outer tube 3. The inner tube 3 has a plurality of projections 13 formed on its outer circumferential surface in a state of projecting radially outward, extending in the longitudinal direction, and arranged at circumferential intervals. Diameter-reduced portions 14 are formed on both end portions of the outer tube 2, and the projections 13 of the inner tube 3 are crushed by the diameter-reduced portions 14. The diameter-reduced portions 14 of the outer tube 2 and the inner tube 3 are brazed, and a clearance between the inner circumferential surface of the diameter-reduced portion 14 and an outer circumferential face of a part free from the projections 13 of the inner tube 13 is closed up with brazing filler metal. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
