Temperature Relations in Shell and Tube Exchangers Having One-Pass Split-Flow Shells

Abstract

Mean temperature difference correction factors are presented in the usual dimensionless groups of P and R for shell and tube heat exchangers where the shell fluid is divided into two streams entering at the center of the shell. Mathematical expressions have been derived for the thermal effectiveness P for both two and four tube passes in terms of UA/wc and wc/WC designated as R. The expressions for the split-flow exchangers with one and with an infinite number of tube passes are also presented. The analysis is further extended so that the correction factor F for split-flow exchangers of four tube passes and an infinite number of tube passes may be used for any even number of tube passes within a practical design range. There is very little difference between correction factors of values above 0.8, for split-flow exchangers with two, four, and infinite number of tube passes, and the conventional 1–2 shell and tube exchanger. An interesting result is noted that for each value of R there is a peak value of P.