Question Bank • QB_EXP_DFE_HEX_007 NAT • 2 Marks

Section 7: Dairy and Food Engineering

Heat Exchangers: LMTD & NTU-Effectiveness Methods

Subtopic: Counterflow heat exchanger LMTD calculation

Question Statement:

Referring to the temperature profile diagram, when $\Delta T_1 = \Delta T_2 = 25.0^\circ\text{C}$ (balanced counterflow condition), the true value of $LMTD$ in $^\circ\text{C}$ is:

Answer Key:

25

Step-by-Step Solution & Explanation

When $\Delta T_1 = \Delta T_2$, $\lim_{\Delta T_1 \to \Delta T_2} \frac{\Delta T_1 - \Delta T_2}{\ln(\Delta T_1 / \Delta T_2)} = \Delta T_1 = 25.0^\circ\text{C}$.
← Previous (QB_EXP_DFE_HEX_034) Next (QB_EXP_DFE_HEX_043) →

Practice In Authentic CBT Exam Interface

Test your skills under authentic timed conditions with live scoring and AIR percentile ranking.

Launch CBT Mock Test