HEAT TRANSFER TUBE

摘要

PROBLEM TO BE SOLVED: To provide a heat transfer tube having high heat transfer performance by exposing a thin portion of a liquid film when a liquid is moved on a surface of a tube by the gravity in a lengthwise direction. SOLUTION: In the heat transfer tube comprising a plurality of strips of fins 10 each having a large twist angleθto a tube axis and spirally formed at a predetermined pitch on an outer periphery and having troughs 11 and ridges 12 alternately formed along the lengthwise direction of the fins 10, the troughs 11 of the partial fins 10 are inclined in a range of the angleθ1=15 to 60 degrees in one direction to the axis, the troughs 11 of another partial fins 10 are twisted in another direction to the axis or inclined in a range to 2θ=-60 degrees or along the axis.