# 1. The following temperatures are obtained at the inlet and exit ports of a counterflow heat…

1. The following temperatures are obtained at the inlet and

exit ports of a counterflow heat exchanger. Find _TLMTD and

compare it with _T as given by Equation VIa.2.5. Data: Th,i =

130 F, Th,o = 111.9 F, Tc,i = 95 F, and Tc,o =

106.3 F

2. A concentric counterflow heat exchanger is used to cool

oil by water. The oil flow rate is 0.1 kg/s and enters at 100 C. Water enters

at 30 C and a flow rate of 0.2 kg/s. The heat transfer area is 5.223 m2

and the overall heat transfer coefficient is 37.8 W/m2 ·K. Find the

rate of heat transfer and exit temperatures. Data: cp,h = 2131

J/kg·K and cp,c = 4178 J/kg·K.