| 摘要 |
<P>PROBLEM TO BE SOLVED: To promote heat exchange while suppressing an increase in pressure loss. <P>SOLUTION: A refrigeration cycle 1 includes a multi-pipe heat exchanger 10 functioning as an internal heat exchanger. The multi-pipe heat exchanger 10 includes an outer pipe 20 and an inner pipe 30. An outside passage 12 where a high pressure refrigerant flows is formed between the outer pipe 20 and the inner pipe 30. An inside passage 13 where a low pressure refrigerant flows is formed inside the inner pipe 30. A plurality of projections 36 are formed outside the inner pipe 30, the projections directing radially outward, that is, directing into the outside passage 12. Recesses 37 are formed inside the inner pipe 30 at positions corresponding to the projections 36. The projections 36 are island-like parts left in a process of deforming a raw material pipe radially inward to form passage grooves 34. The projections 36 promote heat exchange between the high pressure refrigerant and the inner pipe 30. The projections 36 decrease the volume of the outside passage 12. The recesses 37 hardly increase pressure loss of the low pressure refrigerant. <P>COPYRIGHT: (C)2012,JPO&INPIT |
