Water $(mass = 1.4kg/s, C_p= 4.187kJ/kg-K)$ is heated from $40^0C \ to \ 70^0C$ by an oil $(mass = 2kg/s, C_p= 1.9kJ/kg-K)$ entering at $110^0c$ in a counter flow heat exchanger. If overall heat transfer coefficient is $350W/m^2K$, calculate the surface area required.

ṁc=1.4 kg/s (Mass flow rate of cold fluid)

Cpc=4.187 kJ/kgK = 4187 J/kgK (Specific Heat of Cold Fluid)

tc1=40℃=313K (Entry temperature of cold fluid)

tc2=70℃=343K (Exit temperature of cold fluid)

ṁh=2 kg/s (Mass flow rate of Hot fluid)

Cph=1.9 kJ/kgK = 1900 kJ/kgK (Specific Heat of Hot fluid)

th1=110℃=383K (Entry …