Concept explainers
Two 10-ft3 adiabatic tanks are connected by a valve. Initially, one tank contains water at 450 psia with 10 percent quality, while the second contains water at 15 psia with 75 percent quality. The valve is now opened, allowing the water vapor from the high-pressure tank to move to the low-pressure tank until the pressure in the two becomes equal. Determine the final pressure and the final mass in each tank.
FIGURE P4–142E
The final pressure of each tank.
The final mass of each tank.
Answer to Problem 142RP
The final pressure of each tank is
The final mass of each tank is
Explanation of Solution
Write the expression for the energy balance equation.
Here, the total energy entering the system is
Simplify Equation (V) and write energy balance relation of two adiabatic tanks.
Here, the heat to be transfer into the system is
Substitute 0 for
Here, the initial mass of tank A is
Write the expression for initial mass of tank A.
Here, the volume of the tank A is
Write the expression for initial mass of tank B.
Here, the volume of the tank B is
Write the expression for total mass of tank.
Write the expression for initial total internal energy contained in both tanks.
Write the expression for initial is equal to final specific internal energy of tank.
Determine the total volume of both the tanks.
Write the expression for initial is equal to final specific volume of tank.
Write the expression for final mass contained in both tanks.
Conclusion:
At initial pressure and quality of initial state for tank A as 450 psia and 0.10, find the value of initial specific volume and specific internal energy of the tank.
Here, the specific volume of saturated liquid for tank A is
Here, the specific internal energy of saturated liquid for tank A is
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At initial pressure and quality of initial state for tank B as 15 psia and 0.75, find the value of initial specific volume and specific internal energy of the tank.
Here, the specific volume of saturated liquid for tank B is
Here, the specific internal energy of saturated liquid for tank B is
Substitute
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By above calculation from Table A-5E “saturated water” the final pressure of both tanks as
Thus, the final pressure of each tank is
Substitute
Thus, the final mass of each tank is
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Chapter 4 Solutions
Thermodynamics: An Engineering Approach
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