Heat Transfer - Engineering

Q1:

Correction is applied to LMTD for __________ flow.

A parallel

B counter

C cross

D none of these

ANS:C - cross

Correction is applied to the Log Mean Temperature Difference (LMTD) for cross flow. In cross-flow heat exchangers, where the hot and cold fluids flow perpendicular to each other, the temperature profiles are not uniform along the length of the exchanger. As a result, the arithmetic mean temperature difference (ΔTm) calculated from the inlet and outlet temperatures of both fluids may not accurately represent the temperature difference driving the heat transfer process. To account for this non-uniformity, a correction factor is applied to the LMTD calculation in cross-flow heat exchangers. This correction factor adjusts the calculated LMTD to better represent the actual temperature difference experienced by the fluids as they flow through the exchanger. Therefore, correction is applied to LMTD for cross flow.