Hitachi Cable, Inc.

Masakazu Tobe

Yoshio Suzuki

Kenichi Inui

Tadao Otani

In an inner surface-grooved heat transfer tube, a plurality of fins is formed on the inner surface thereof along a line forming a first predetermined angle with respect to the longitudinal axis of the tube, a plurality of notches is defined on the fins along a line forming a second predetermined angle with respect to the longitudinal axis, and the depth Hf' of the notches is specified to be 20% or more and below 40% (0.2.ltoreq.Hf'/Hf&lt;0.4) with respect to the height Hf of the fins, to provide an inner surface-grooved heat transfer tube which can suppress pressure loss of a refrigerant, and by which improvements in performance of condensation and evaporation are intended. In addition no increase of power consumption is required for the pump.

Growing community of inventors

Ibaraki, Japan

Masakazu Tobe