Heat transfer tube
AssigneeGeneral Atomic Company
InventorJack S. Yampolsky
Life of this patent
Estimating the term…
Abstract
A spirally fluted metallic heat transfer tube is disclosed wherein the finished tube has improved heat transfer performance through the provision of a predetermined number range of multiple start continuous helical flutes formed along its longitudinal length, the flutes having specific helix angle relation and flute height to tube hydraulic diameter ratio so as to establish a ratio of thermal diffusivity to momentum diffusivity greater than 1.
Claims6
A heat transfer tube for effecting heat transfer between the tube wall and a fluid flowing through said tube, comprising a substantially straight axis metallic tube having a plurality of multiple start spiral flutes of substantially uniform configuration formed along the length of the tube wall, said flutes each forming a helix angle of between approximately 25 to 50 degrees relative to the axis of the tube, each of said flutes having a flute height sufficient to establish a flute height to tube hydraulic diameter ratio greater than approximately 0.025, and wherein the number of said multiple start flutes is selected by the combination of Nx tan .phi./D.sub.h >20 where;
- Nx=the number of flutes,
- .phi.=the helix angle of the flutes, and
- D.sub.h =the hydraulic diameter of the tube
Dependencies are inferred from the claim text.