Question

A chemical having specific heat of 3.3 kJ/kg K flowing at the rate of 20000 kg/h enters a parallel flow heat exchanger at 120°(C) The flow rate of cooling water is 50000 kg/h with an inlet temperature of 20°(C) The overall heat transfer coefficient is 1050 W/m\(^2\)K. The heat transfer area is 10 m\(^2\). Take for water, specific heat = 4.186 kJ/kgK. Effectiveness of the heat exchanger will be —————.

• A. 0.2
• B. 0.3
• C. 0.4
• D. 0.6

Hint:

Effectiveness is the measure of how efficiently a heat exchanger transfers heat between two fluids.

Answer 1

The Correct Option is C

- The effectiveness (\( \varepsilon \)) of a heat exchanger is given by: \[ \varepsilon = \frac{Q_{{actual}}}{Q_{{max}}} \] Using heat exchanger effectiveness calculations, the effectiveness comes out to be approximately 0.4. 
Conclusion: The correct answer is option (C).