To improve the condensing performance as well as the evaporating performance of refrigerant.
A refrigerant 4, utilized for a refrigerating cycle, flows under the condition of gas and liquid two-phase while a heat transfer tube with internal surface grooves is provided with a plurality of spiral inner surface fins 2, condensing or evaporating the refrigerant 4, and internal surface grooves 3, provided between respective internal surface fins 2. Respective internal surface grooves 3a, 3b are constituted so as to have at least two kinds of groove widths of a groove width W1, facilitating the condensing of the refrigerant 4, and a groove width W2, facilitating the evaporation of the same. The groove width of the internal grooves 3a, 3b is changed so as to be two kinds of more of a large groove width W1 and a small groove width W2 while the large groove width W1 and the small groove width W2 are arranged alternately. Accordingly, liquid is hardly reserved in the large groove width W1 and the condensing performance of the liquid is improved while the liquid is readily reserved in the small groove width W2 and the evaporating performance of the liquid is improved.
| WO/2018/021030 | METHOD FOR PRODUCING HEAT EXCHANGER |
| JPS58183470 | 【考案の名称】冷凍機用2重管式水冷型熱交換ユニツト |
| WO/2013/153983 | AIR-CONDITIONING DEVICE |
UCHIDA MARI
SHIKAZONO NAOKI
FUKUSHIMA TOSHIHIKO
