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Thermodynamics Question

  • Thread starter ashkash
  • Start date
  • #1
32
0

Homework Statement



Determine the work required per pound mass to isothermally and frictionlessly compress R-134a in a closed system from a saturated vapor to a saturated liquid at 20 °F.

Homework Equations





The Attempt at a Solution



I do not know where to begin with this problem. Any help would be appreciated. thanks.
 

Answers and Replies

  • #2
157
0
Start with the first law of thermodynamics. Probably a few assumptions in the problem, like KE and PE = ?
Also you'll need the charts, probably in the back of your text.
 
  • #3
FredGarvin
Science Advisor
5,066
7
Just to add:

Write down the first law.

Isothermal.....Q=0
Isentropic.....No Entropy production
You can also assume no potential or kinetic changes.

What is left?
 

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