摘要 |
A heat exchanger (10) for transferring heat between two fluids consists of a shell (28) surrounding at least two tube bundles (34, 50, 60) attached at both ends to a tube header (16). Each of the tube bundles (34, 50, 60) is constructed from a plurality of individual tubes that are twisted into identical helixes formed about a common helical axis. Because each individual tube is formed in the shape of a helix, rather than as a straight tube, thermal elongation of the individual tubes results in a considerably reduced axial force on the tube attachments and tube header (16). Use of multiple tube bundles (34, 50, 60) wound with opposite twist direction improves spacing efficiency between tubes. |