An engineer operates a counter-flow shell-and-tube heat exchanger. It is known that the A fluid (specific…

An engineer operates a counter-flow shell-and-tube heat
exchanger. It is known that the A fluid (specific heat is 1.0
J/g*°C) flows into the outside of the tube at a mass flow rate of
100 g/hr. The inlet temperature is 90 ° C and the outlet
temperature is At 70 ° C, the B fluid flows into the tube. The
inlet temperature is 20 ° C and the outlet temperature is 65 ° C.
If the heat transfer effective area is 20 m 2 , answer
the following questions:
(1) What is the logrithm average temperature difference (ΔTln)
for °C?
(2) What is the total heat transfer coefficient (Uo) J/(hr*m2
*°C)? (ln2=0.693)