BX-8 Incremental Shellside Flow Boiling Methods
This report describes incremental shellside flow boiling methods used in a comprehensive model that predicts heat transfer in TEMA-type shell-andtube heat exchangers. HTRI has developed new methods for determining the thin-film heat transfer coefficient, nucleate boiling suppression factor, transition boiling criteria, mist flow criteria, and mist flow heat transfer coefficient. When compared with overall horizontal thermosiphon data taken for E- and X-shell heat exchangers, the model gives satisfactory results over a wide range of process conditions and geometrical configurations. The comparison yields a mean predicted-to-measured shellside heat transfer coefficient ratio of 0.986 ± 0.124. The model adequately predicts heat transfer for most wet-wall conditions but requires additional experimental validation for dry-wall conditions. The new methods also feature a more rigorous internal circulation-type kettle reboiler option that replaces the approximate methods in RKH.