DOUBLE PIPE AND HEAT EXCHANGER HAVING THE SAME

PURPOSE: A double pipe and a heat exchanger comprising the same are provided to enhance the heat conductivity and to improve the efficiency and the performance of an air conditioning system for a vehicle. CONSTITUTION: A double pipe(10) comprises a plurality of partition walls(11a) and a plurality of protrusions(13a). The partition walls are extended between the external pipe(11) and the internal pipe(13) of a heat exchanger in a length direction and are arranged at given intervals in a radial direction. The protrusions are respectively corresponded to the partition walls, are projected from the inner circumference of an inner pipe toward the center of the inner pipe and are extended in a length direction. An outer pipe, the inner pipe, the partition walls and the protrusions are integrally formed. A plurality of grooves are formed on the outer circumference of the outer pipe. The grooves are formed at given intervals in the circumference direction of the outer pipe and extended in the length direction.