Double-pipe heat exchanger and refrigeration cycle device

• Main Authors: YANACHI SATORU, KATO YOHEI
• Format: Patent
• Language: English
• Published: 28.10.2015
• Subjects: BLASTING; DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OFGENERAL APPLICATION; HEAT EXCHANGE IN GENERAL; HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS,IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT; HEATING; LIGHTING; MECHANICAL ENGINEERING; WEAPONS

Provided are a double-pipe heat exchanger and the like with which the heat exchange performance can be increased when a two-phase flow flows in a second flow path. This double-pipe heat exchanger (1) is equipped with an expanded-heat-transfer-area pipe (11) having protrusions and recesses in the radial direction. The inner surface of the portion of the expanded-heat-transfer-area pipe (11) in contact with the inner surface of an outer pipe (3), and the portion of the inner surface of the outer pipe that defines a second flow path (23) in conjunction with the outer surface of the expanded-heat-transfer-area pipe, are areas in which grooves are not formed, that is, are grooveless surfaces. In addition, a candidate groove formation area is provided, with this area comprising the portion of the expanded-heat-transfer-area pipe when the area in which grooves are not formed is excluded from the portion of the inner surface that defines the second flow path in conjunction with the outer surface of an inner pipe, and the portion of the outer surface of the expanded-heat-transfer-area pipe that defines the second flow path in conjunction with the inner surface of the outer pipe, and the portion of the outer surface of the inner pipe (5) that defines the second flow path in conjunction with the inner surface of the expanded-heat-transfer-area pipe. Grooves extending in the direction of flow are formed in all or a part of the candidate groove formation area.