DOUBLE PIPE HEAT EXCHANGER AND REFRIGERATING CYCLE DEVICE USING IT

摘要

PROBLEM TO BE SOLVED: To provide a double pipe heat exchanger for easy work and lower costs as well as promoted heat exchange amount. SOLUTION: There are provided an internal pipe 11 where a fluid comes into from one end while exiting through the other end, and an external pipe 12 which is provided outside the internal pipe constituting a double pipe structure and comprises a coolant inlet 12a and a coolant outlet 12b. The internal pipe 11 is streaked with radial protrusion 13 in cross section and with continuous structure in the axial direction. Thus inside and outside areas are increased for improved heat exchange amount while a recessed/protruding streak is easily worked with drawing as an example.