Question

2. Consider a process in which two tanks A and B are connected by a valve. Tank A, which is insulated, has a volume of 600 liters and contains steam at 1.4 MPa, 300°C. Tank B, which is uninsulated, has a volume of 300 liters and contains steam at 200 kPa, 200°C. The valve connecting the two tanks is now opened and steam flows from A to B until the temperature in A reaches 250°C, at which time the valve is closed. During this process, heat is transferred from B to the surroundings at 25°C such that the temperature inside B remains at 200°C. It may be assumed that the steam remaining inside A has undergone a reversible adiabatic process. (a) Represent the changes in the two tanks on T-s diagrams. (b) Determine the final pressure in each tank. (c) Determine the final mass in Tank B. (d) Determine the entropy change for the system and the surroundings for the process. (e) What is the net entropy change for the process? () Comment on your results.

Answer 1