Project ForgeSteam in the condenser of a thermal power plant is to be condensed at a temperature of 30°C with cooling water which enters the tubes of the condenser at 14°C and exits at 22°C. The total surface area of the tubes is 50 m², and the overall heat transfer coefficient is 2000 W/m²K. The heat transfer (in MW) to the condenser is __________ (correct to two decimal places).
Explanation
The condensing steam is at a constant 30°C. ΔT1 (at water inlet) = 30−14 = 16°C, ΔT2 (at water outlet) = 30−22 = 8°C. LMTD = (ΔT1−ΔT2)/ln(ΔT1/ΔT2) = (16−8)/ln(16/8) = 8/ln2 ≈ 11.54°C. Q = U×A×LMTD = 2000×50×11.54 ≈ 1,154,200 W ≈ 1.154 MW.
Source: GATE ME 2018 Session 2 (Set 2) (2018)
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