12- Question 8 by Kambiz Ehsani - Second Law of the Thermodynamics - 4/27/2018 - Solved

The question was adopted from the Van Wylen Textbook 3rd edition:

A cyclic machine is used to transfer heat from a higher to a lower temperature reservoir, as show in the picture below.Determine if this machine with the energy transfer,values as shown , is reversible or irreversible or impossible.

Solution;

You have to examine the cycle for the Carnot cycle. For the given TH  , TL

Then the Carnot cycle efficiency will be = ( TH  - TL ) / TH = 1000 - 400 / 1000 = 0.60

Efficiency of the given system = Wnet / Qh = 0.615  > Carnot Efficiency or 0.6

Impossible