In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is ______________ °C?

Question

Accepted Answer

∞. The arithmetic mean temperature difference (LMTD) is calculated using the formula $	ext{LMTD} = \frac{\Delta T_1 - 	ext{LMTD}_2}{\ln(\frac{\Delta T_1}{\Delta T_2})}$. Since one of the end temperatures results in a zero denominator or an undefined calculation based on standard assumptions, the result is often considered infinite ($\infty$) in simplified contexts.