Example 33.1 Use the increase of entropy principle to demonstrate the following engine is not possible: it absorbs heat 1000kJ from a 167 C hot reservoir,and reject heat 568 kJ to a cold reservoir at 7'C.The cycle net work is 432 kJ. Solution:take the engine,hot reservoir,cold reservoir as a closed, adiabatic system.For a cycle, -1000kJ =-2.272kJ/K (273.15+167)K 568kJ =2.027kJ/K (273.15+7)K =0 reversible? Asso=-2.272kJ/K+2.027kJ/K=-0.245kJ/K<0 So,the engine is not possible to work 上游充通大学 Wednesday,April 19,2017 5 SHANGHAI JLAO TONG UNIVERSITYWednesday, April 19, 2017 5 Use the increase of entropy principle to demonstrate the following engine is not possible: it absorbs heat 1000kJ from a 167 ℃ hot reservoir, and reject heat 568 kJ to a cold reservoir at 7℃. The cycle net work is 432 kJ. hot res h b,rev 1 000 kJ ( ) 2.272 kJ/K (273.15 167) K Q s T        So, the engine is not possible to work cold res b,rev 568 kJ ( ) 2.027 kJ/K (273.15 7) K Qc s T      engine   s 0 iso        s 2.272 kJ/K 2.027 kJ/K 0.245 kJ/K 0 Solution: take the engine, hot reservoir, cold reservoir as a closed, adiabatic system. For a cycle, Example 33.1 ? reversible?