Question

6.50 m A closed, rigid tank contains 5 kg of air initially at 300 K, 1 bar. As illustrated in Fig. P6.50, the tank is in contact with a thermal reservoir at 600 K and heat transfer occurs at the boundary where the temperature is 600 K. A stirring rod transfers 600 kJ of energy to the air. The final temperature is 600 K. The air can be modeled as an ideal gas with cy = 0.733 kJ/kg . K and kinetic and potential energy effects are negligible. Determine the amount of entropy transferred into the air and the amount of entropy produced, each in kJ/K. This portion of the boundary is at temperature Tres = 600 K Reservoir ihre H at Tres W =-600 kJ Air initially at 300 K, 1 bar. Finally, T2 = 600 K

Answer 1

ANSWETE Given, tank mass ska Shitaly temperature -300k. thermal reservoir = 600k vod transfers Energy = booky C1 0.733 kJ ligte The Energy balance Equation. AKE + APE+AU = a-W 0+0+Al Q-W Q = m(U2 -Uitw Q = mc (Tq - Ti ) + W 5(0433)/600-300) + (-600 ks) Q 2 499.5 kJ the entsepy transtered into air S- S = 499.5 600 (s = 0,8325 kJ/k Ideal gas model solution to change in Entropy a in [ + J + RM Colin [+R6[1] ( 92-S,

Cv In [9] (S2-5) = 0733x In 1600 300 [S₂ - 3 - 015081 kJ /kg.k the amount of Entropy produted. a (S2-S,) to m (S₂-5.) - solt To 6 (0.5081) - 10:8326 1.708 kJ/k so