a.) The temperature of the R-134a when the piston reaches the stops.
b.) The boundary work done during this expansion process.
c.) The heat transfer during this expansion process.
d.) Show this process on a PV Diagram.
13 Old Comments
Tuesday, September 30, 2008
TE 303 - HW #4, P6 - Isobaric Expansion of R-134a - 15 pts
A piston-and-cylinder device with a set of stops contains 10 kg of R-134a. Initially, 8.0 kg of the refrigerant is in the liquid phase and the temperature is -8.0oC. Now, heat is transferred slowly into the refrigerant until the piston hits the stops. At this point, the volume is 400 L. Determine:
13 Old Comments
13 Old Comments
Subscribe to:
Post Comments (Atom)
3 comments:
ANSWERS:
a) T2 = -8 C
b) W = +/- 45.4 kJ (YOU determine the sign)
c) Q = +/- 466.6 kJ (YOU determine the sign)
HINT:
c) Use the first law energy balance to find Q. If you plug in your work equation for part b), you will find that Q12 = deltaH. (See the Isobaric Processes slide in Thermo-CD).
which book did you use? i need it!
thank you
Anon 5:04pm
I did not teach this course when this was posted. Dr. P did. I am not sure she was using a textbook in her course that year. She MAY have been using Cengel & Boles as a reference, but I am not sure.
Best of luck to you.
Dr. B
Post a Comment