Chapter 6, Problem 6.62P

Water vapor enters a valve at 0.7 bar, 360oC, and exits at 0.35 bar. If the water vapor undergoes a throttling process (means constant enthalpy & reduce pressure significantly), determine the rate of entropy production within the valve, in kJ/K per kg of water vapor flowing.

C6 1.

One kilogram of water contained in a piston–cylinder assembly, initially saturated vapor at 100 kPa, is condensed at constant pressure to saturated liquid. Consider an enlarged system consisting of the water and enough of the nearby surroundings that heat transfer occurs only at the ambient temperature of 25oC. Assume the state of the nearby surroundings does not change during the process, and ignore kinetic and potential energy effects.  For the enlarged system, determine the heat transfer, in kJ, and the entropy production, in kJ/K.     Determine the heat transfer, in kJ. Q12 =                    kJ

One-quarter Ibmol of oxygen gas (O₂) undergoes a process from p₁ = 20 lbf/in², T₁ = 500°R to p₂ = 150 lb/in². For the process W = -500 Btu and Q = -202.5 Btu. Assume the oxygen behaves as an ideal gas. Determine T2, in °R, and the change in entropy, in Btu/°R.

One-quarter lbmol of oxygen gas (O2) undergoes a process from p1 = 20 lbf/in2, T1 = 500oR to p2 = 150 lbf/in2. For the process W = -500 Btu and Q = -240.0 Btu. Assume the oxygen behaves as an ideal gas. Determine T2, in oR, and the change in entropy, in Btu/oR.

Water contained in a closed, rigid tank, initially at 100 lb;/in², 800°F, is cooled to a final state where the pressure is 50 lb;/in?. Determine the quality at the final state and the change in specific entropy, in Btu/lb-°R, for the process.

One-quarter Ibmol of oxygen gas (O₂) undergoes a process from p₁ = 20 lb/in², T₁ = 500°R to p₂ = 150 lb/in². For the process W= -500 Btu and Q = -140.0 Btu. Assume the oxygen behaves as an ideal gas. Determine T2, in "R, and the change in entropy. in Btu/°R. Step 1 Determine T₂, in °R. Your answer is correct. T₂- 78862 Hint Step 2 * Your answer is incorrect. A$12 Determine the change in entropy, in Btu/°R. °R i 0.1968 eTextbook and Media Btu/ºR Attempts: 1 of 4 used

: Consider the reversible adiabatic flow of steam through a nozzle. Steam enters 1 MPa, 300°C, with a velocity of 30 m/s. The pressure of the steam at the nozzle Q2 / the nozzle at exit is 0.3MP.. Determine the exit velocity of the steam flow from the nozzle, assuming a reversible, adiabatic, steady state, steady flow process.

= 71°C with v₁ = 0.201 m³/kg. The gas v1 A piston-cylinder assembly holds 1.2 kg of air initially at T₁ undergoes a process as an ideal gas and reaches a final state at T2 = 149° C with v2 = Determine the change in entropy AS in kJ/K. Assume c = 0.72 kJ/kg. K. 0.725 m³/kg. (a) AS = Ex: 0.888 kJ/K (b) Is the process adiabatic? Pick (c) What is the direction of heat transfer? Pick Air