Question Bank • QB_EXP_DFE_HEX_028 NAT • 2 Marks

Section 7: Dairy and Food Engineering

Heat Exchangers: LMTD & NTU-Effectiveness Methods

Subtopic: Counterflow heat exchanger LMTD calculation

Question Statement:

For the counterflow heat exchanger with $C_r = C_{\text{min}}/C_{\text{max}} = 1.0$ and $NTU = 2.0$, determine the thermal effectiveness $\varepsilon = \frac{NTU}{1 + NTU}$ in percentage ($\%$) (round off to one decimal place).

Answer Key:

66.7

Step-by-Step Solution & Explanation

For $C_r = 1.0$ in counterflow: $\varepsilon = \frac{NTU}{1 + NTU} = \frac{2.0}{1 + 2.0} = \frac{2}{3} = 0.6667 \to 66.7\%$.
← Previous (QB_EXP_DFE_HEX_025) Next (QB_EXP_DFE_HEX_037) →

Practice In Authentic CBT Exam Interface

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

Launch CBT Mock Test