Concept explainers
(a)
The final pressure in the tank.
(a)
Answer to Problem 118P
The final pressure in the tank is
Explanation of Solution
At the final observation, the valve is closed and the tank composed with one-half water and vapor at the temperature of
Hence, the pressure
Refer Table A-4E, “Saturated water-Temperature table”.
The saturation pressure corresponding to the temperature of
Conclusion:
Hence, the pressure of the mixture in the tank at the final state is
(b)
The amount of steam entered in the tank.
(b)
Answer to Problem 118P
The amount of steam entered in the tank is
Explanation of Solution
Write the equation of mass balance.
Here, the inlet mass is
The change in mass of the system for the control volume is expressed as,
Here, the suffixes 1 and 2 indicates the initial and final states of the system.
Consider the given rigid tank as the control volume.
At final state, the valve is close and the steam is not allowed to exit, i.e.
Rewrite the Equation (I) as follows.
At initial state, the tank consist of saturated water vapor
Write the formula for mass of steam
Here, the volume is
At final state, the tank consist of mixture of vapor
Write the formula for mass of steam
Here, the suffixes
It is given that the tank consist of one-half of the volume of the tank is occupied by liquid water.
At the initial state (1):
The tank consist of saturated water vapor
Refer Table A-4E, “Saturated water-Temperature table”.
Obtain the initial specific volume
At the final state (2):
The tank consist of mixture of vapor
Refer Table A-4E, “Saturated water-Temperature table”.
Obtain the final fluid and gaseous specific volume corresponding to the temperature of
Conclusion:
Substitute
Substitute
Substitute
Thus, the amount of steam entered in the tank is
(c)
The amount of the heat transfer.
(c)
Answer to Problem 118P
The amount of the heat transfer is
Explanation of Solution
Write the energy balance equation.
Here, the heat transfer is
Since the tank is not insulated, the heat transfer occurs through the tank wall. In control volume, there is no work transfer, i.e.
The Equation (V) reduced as follows.
At the final state, the tank is composed of vapor and liquid. Hence, the final state energy is expressed as follows.
At the line (while entering the tank):
The supply line consist of superheated water vapor.
Refer Table A-6E, “Superheated water”.
Obtain the line enthalpy
At the initial state (1):
The tank consist of saturated water vapor
Refer Table A-4E, “Saturated water-Temperature table”.
Obtain the initial internal energy
At the final state (2):
The tank consist of mixture of vapor
Refer Table A-4E, “Saturated water-Temperature table”.
Obtain the final fluid and gaseous internal energies corresponding to the temperature of
Conclusion:
Substitute
Substitute
Here, the negative sign indicates that the heat transfer occurs from the tank to the surrounding.
Thus, the amount of the heat transfer is
Want to see more full solutions like this?
Chapter 5 Solutions
Thermodynamics: An Engineering Approach
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY