Please show work! Thanks! Ammonia enters a control volume at a temperature of 15
ID: 1939871 • Letter: P
Question
Please show work! Thanks!Ammonia enters a control volume at a temperature of 150°C and a pressure of 16.0 bar. The incoming volumetric flow rate is 10 m3/s through a pipe that is 0.5 m in diameter. The ammonia is cooled in the device and exits either as a saturated liquid at 6.0 bar or saturated vapor at 6.0 bar. The saturated vapor exits through a pipe with a diameter of 0.5 m. The mass flow rate of saturated liquid ammonia exiting the control volume is measured to be 20 kg/s. The saturated liquid leaves through a pipe 10 cm in diameter. Assume steady state and uniform flow at each inlet or exit.
a) Determine the velocity (m/s) and mass flow rate (kg/s) of the ammonia saturated vapor stream leaving the control volume.
Explanation / Answer
At inlet, ammonia 150C 16 bar --> =8.1246 kg/m3
mass flow rate in = x volume flow rate = 8.1246 x 10 = 81.246 kg/s
conservation of mass: mass flow rate in = mass flow rate out vapor + mass flow rate out liquid
81.246 = 20 + mass flow rate out vapor
mass flow rate out vapor = 61.246 kg/s
At sat vapor exit at 6 bar --> =4.758 kg/m3
Volume flow vapor out = mass flow rate out vapor / = 61.246 / 4.758 = 12.872 m3/s
Volume flow vapor out = AV --> V = 12.872 / (0.252) = 65.56 m/s