The relationship between design parameters and entropy generated in a heat exchanger is defined by..

The relationship between design parameters and entropy
generated in a heat exchanger is defined by Eq. (11.33). This relationship is
the subject of Problem 11.11. Show that the operating point corresponding to
equal outlet temperatures must correspond to maximum entropy generation. Assume
that the temperature effectiveness increases monotonically with NTU. Calculate
the number of transfer units that correspond to the maximum entropy generation
operating point for a counterflow exchanger with C* = 1.

A two-fluid heat exchanger of an arbitrary flow arrangement
has a specified number of
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The relationship between design parameters and entropy
generated in a heat exchanger is defined by Eq. (11.33). This relationship is
the subject of Problem 11.11. Show that the operating point corresponding to
equal outlet temperatures must correspond to maximum entropy generation. Assume
that the temperature effectiveness increases monotonically with NTU. Calculate
the number of transfer units that correspond to the maximum entropy generation
operating point for a counterflow exchanger with C* = 1.

A two-fluid heat exchanger of an arbitrary flow arrangement
has a specified number of transfer units NTU, and the heat capacity rate ratio
C*. The inlet temperatures of both fluids are known and their ratio is # ¼ T1;i/T2;i.
Derive the relationship between the entropy generated in this exchanger and its
design parameters as given by Eq. (11.33), in which the pressure drops are
neglected. Subsequently, calculate the entropy generation for a counterflow
heat exchanger having C* = 1 and an inlet temperature ratio of 0.5. Perform the
calculations for NTU = 1, 5, and 10 and discuss the change in entropy
generation with increased heat exchanger size. Finally, show how Eq. (11.28)
would change if there is finite pressure drop.

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