| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact internal heat exchanger having superior efficiency of heat exchange by regulating a pressure loss.SOLUTION: An internal heat exchanger 6 is used in a freezing cycle where a refrigerant circulates in four steps of evaporation, compression, condensation and expansion, and includes a high pressure side flat pipe 10 where refrigerant flow paths in a high pressure side are arranged parallel and a low pressure side flat pipe 20 where refrigerant flow paths in a low pressure side are arranged parallel. The high pressure side flat pipe and the low pressure side flat pipe are bent in a U-shape in advance, and the high pressure side flat pipe is arranged in the inside to the low pressure side flat pipe. Also, the high pressure side flat pipe, the low pressure side flat pipe, and a header pipes are brazed with at least refrigerant flow inlet side ends 13, 23 of respective refrigerant flow inlets and refrigerant flow outlets of the high pressure side flat pipe and the low pressure side flat pipe inserted in the header pipes via slits arranged in the header pipes 30A, 30C. |
