What is the ua value of a finned coil evaporator having the following areas: refrigerant side, 15 m2; air side prime, 13.5 m2, and air side extended 144 m2? the refrigerant-side heat transfer coefficient is 1300 w/m2.k and the air side coefficient is 48 w/ m2.k. the fin effectiveness is 0.64

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]