A heat exchanger performs as shown below in the Figure A for safety reasons. An engineer suggests that it would be wise to double the heat transfer area so as to double the heat transfer rate. The suggestion is made to add a second, identical exchanger as shown in Figure B. Evaluate this suggestion, i.e., show whether or not the heat transfer rate would double.
GIVEN
Case 1
Heat exchanger as shown above.
Overall heat transfer coefficient times the transfer area (UA) = 40,000 kJ/(hr K)
Heat capacity rates
Ch = 80,000 kJ/(h K)
Cc = 40,000 kJ/(h K)
Entering temperatures
Tb,in = 400 K
Tc,in = 300 K
Case 2
Two of the same heat exchanges as shown above in Figure B.
ASSUMPTIONS
Heat exchangers are simple counterflow geometry