Air (Cp = 1.005 kJ/kg · K) is to be preheated by hot exhaustgases 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 0.90kg/s. The combustion gases (Cp = 1.1 kJ/kg · K) enter at a rate of1.1 kg/s and 150◦C. The product of the overall heat transfercoefficient and the heat transfer surface area is U A = 1200 W/K.Assuming both fluids to be unmixed, use the effectiveness-NTUmethod to determine
(a) the heat exchanger effectiveness,
(b) the rate of heat transfer, and
(c) the exit temperature of the exhaust gases.
