| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a double-wall-tube heat exchanger having excellent heat exchanging performance. <P>SOLUTION: This double-wall-tube heat exchanger includes an outer tube 2, and an inner tube 3 disposed concentrically 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. The inner tube 3 has a plurality of interior fins 12 formed on its inner circumferential surface in a state of projecting radially inward, extending in a longitudinal direction, and are arranged at circumferential intervals. The inner tube 3 has a plurality of elongated 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. The interior fins 12 are greater in height than the elongated projections 13. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
