STG-11 Single-Phase Heat Transfer and Pressure Drop in Double-Pipe Heat Exchangers with Longitudinal Fins

J. W. Palen
2001; rev 03/2010

Double-pipe heat exchangers are appropriate for use when heat duty is not large and a simple, flexible means of exchanging heat is required. They are especially practical for viscous fluids because the single-tube arrangement assures good distribution. When the heat transfer coefficient of the annulus fluid is much lower than that of the tubeside fluid, fins in the annulus increase performance. So that we can offer this option in HTRI software, we have reviewed the literature and made recommendations to adapt these methods. The only usable data, published in graphical form for design, were generated by an equipment manufacturer in 1945. Two later methods attempted to adapt tubeside methods, but they do not agree well with the finned annulus heat transfer data in the laminar and transition regions. This report presents new correlations that more accurately reflect the published design curves based on the original data. Pressure drop prediction presented no problem because the data agree with standard published tubeside methods, such as those used by HTRI, when the equivalent diameter is used for the annulus critical dimension.