Flow rate 2 m3/h, oil with a specific heat of 2.219 J/kg.°C and a density of 840 kg/m3 in a heat exchanger from 160 °C to 40 °C
is cooled. While the oil is cooling, its flow rate is 15 m3./hour, water with a specific heat of 4.177 J/kg.°C and a density of 998 kg/m3 is heated to 35 °C. until it warms up. Total heat transfer coefficient (U) of the heat exchanger 1.150 W/m2×°C Since;
a. parallel current,
b. Find the heating surface area for countercurrent situations.