Concept explainers
Determine the specific volume of superheated water vapor at 15 MPa and 350°C using (a) the ideal-gas equation, (b) the generalized compressibility chart, and (c) the steam tables. Also determine the error involved in the first two cases.
(a)
The specific volume of superheated water vapour based on the ideal gas equation.
The error involved.
Answer to Problem 84P
The specific volume of superheated water vapour based on the ideal gas equation is
The error involved is
Explanation of Solution
Write the equation of specific volume of superheated water using ideal gas equation of state.
Here, gas constant is R, pressure and temperature of R-134a are P and T respectively.
Calculate the percentage of error involved.
Here, specific volume at pressure and temperature of 15 MPa and
Conclusion:
Refer to Table A-1, obtain the gas constant, R of water as
Substitute
Thus, the specific volume of superheated water vapour based on the ideal gas equation is
Refer to Table A-6, obtain the value of
Substitute
Thus, the error involved is
(b)
The specific volume of superheated water vapour based on the generalized compressibility chart.
The error involved.
Answer to Problem 84P
The specific volume of superheated water vapour based on the generalized compressibility chart is
The error involved is
Explanation of Solution
Calculate the reduced pressure.
Here, pressure of superheated water vapour is P and critical pressure is
Calculate the reduced temperature.
Here, temperature of superheated water vapor is T and critical temperature is
Calculate the specific volume of superheated water vapour based on the generalized compressibility chart.
Here, the specific volume at ideal condition is
Conclusion:
Refer to Table A-1, obtain the critical pressure and critical temperature of water.
Substitute 22.06 MPa for
Substitute 647.1 K for
Refer to figure A-15, “The compressibility chart”, obtain the compressibility factor, Z by reading the calculated reduced pressure and reduced temperature as 0.65.
Substitute 0.65 for Z and
Thus, the specific volume of superheated water vapour based on the generalized compressibility chart is
Substitute
Thus, the error involved is
(c)
The specific volume of superheated water vapour based on the data from tables.
Answer to Problem 84P
The specific volume of superheated water vapour based on the data from table is
Explanation of Solution
Refer to Table A-6, obtain the specific volume at pressure and temperature of 15 MPa and
Thus, the specific volume of superheated water vapour based on data from steam tables is
Want to see more full solutions like this?
Chapter 3 Solutions
Thermodynamics: An Engineering Approach
- Steam at 400°C has a specific volume of 0.02 m3 /kg. Determine the pressure of the steam based on (a) the ideal-gas equation, (b) the generalized compressibility chart, and (c) the steam tablesarrow_forwardDetermine the specific volume of refrigerant-134a vapor at 0.9 MPa and 70°C based on (a) the ideal-gas equation, (b) the generalized compressibility chart, and (c) data from tables. Also, determine the error involved in the first two casesarrow_forwardConsider water initially at 20°C and 1 atm. Determine the final density of the water (a) if it is heated to 50°C at a constant pressure of 1 atm, and (b) if it is compressed to 100-atm pressure at a constant temperature of 20°C. Take the isothermal compressibility of water to be α = 4.80 × 10−5 atm−1.arrow_forward
- Determine the specific volume, in m3/kg, of R-134a at a pressure of 100 kPa and temperature of 10°C.arrow_forwardA 300-m3 rigid tank is filled with saturated liquid-vapor mixture of water at 178 kPa. If 25 percent of the mass is liquid and 75 percent of the mass is vapor, what is the total mass in the tank?arrow_forwardSince the compressibility factor of the superheated water vapor at 15 MPa pressure and 550 ° C temperature is 0.7, what is the density of this gas found by the compressibility factor?arrow_forward
- Determine the specific volume of superheated water vapor at 15.65 MPa and 355.11 C, using the generalized compressibility chart. Assume that the compressibility factor is 0.65. Round off your answer to 4 decimal places. R = 0.4615 kPa·m3/kg·K Tcr = 647.1 K Pcr = 22.06 MPaarrow_forwardNitrogen at 150 K has a specific volume of 0.041884 m3 /kg. Determine the pressure of the nitrogen using (a) the ideal-gas equation and (b) the Beattie-Bridgeman equation. Compare your results to the experimental value of 1000 kPa.arrow_forwardWhat is the percentage of error involved in treating carbon dioxide at 5 MPa and 25°C as an ideal gas?arrow_forward
- Reconsider Prob Solve the problem using appropriate software. Compare the temperature of water for the three cases at constant specific volume over the pressure range of 0.1 MPa to 1 MPa in 0.1-MPa increments. Plot the percent error involved in the ideal-gas approximation against pressure, and discuss the results.arrow_forwardA vessel of 0.03 m33 capacity contains gas at 3.5 bar pressure and 35°C temperature. Determine the mass of the gas in the vessel. If the pressure of this gas is increased to 10.5 bar while the volume remains constant, what will be the temperature of the gas ? For the gas take R = 290 J/kg K.arrow_forwardA rigid tank contains nitrogen gas at 227°C and 100 kPa gage. The gas is heated until the gage pressure reads 250 kPa. If the atmospheric pressure is 100 kPa, determine the final temperature of the gas, in °C.arrow_forward
- 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