Air (Cp = 1.005 kJ/kg · K) is to be preheated by hot exhaust gases in...

Air (Cp = 1.005 kJ/kg · K) is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters the furnace. Air enters the heat exchanger at 95 kPa and 20◦C at a rate of 0.90 kg/s. The combustion gases (Cp = 1.1 kJ/kg · K) enter at a rate of 1.1 kg/s and 150◦C. The product of the overall heat transfer coefficient and the heat transfer surface area is U A = 1200 W/K. Assuming both fluids to be unmixed, use the effectiveness-NTU method to determine

(a) the heat exchanger effectiveness,

(b) the rate of heat transfer, and

(c) the exit temperature of the exhaust gases.

Expert Solution

samet mamat answered 1 year ago

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