Heat Transfer Calculation for Vapor Flow in a Cylinder-Piston System

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SUMMARY

The discussion focuses on calculating heat transfer for a vapor flow process involving R-134a in a cylinder-piston system. The tank contains saturated vapor at 30˚C and a volume of 100 L, with the process ending when the pressure drops to 200 kPa. The heat transfer calculated for this process is 101.3 kJ. Key equations used include the energy balance equation E2-E1 = Q - W and the work equation Work = Pressure * Change in volume.

PREREQUISITES
  • Understanding of thermodynamic principles, specifically the first law of thermodynamics.
  • Familiarity with saturated vapor properties of refrigerants, particularly R-134a.
  • Knowledge of pressure-volume work calculations in piston-cylinder systems.
  • Experience with thermodynamic tables for refrigerants.
NEXT STEPS
  • Study the properties of R-134a using thermodynamic tables.
  • Learn about the first law of thermodynamics and its application in closed systems.
  • Explore detailed examples of heat transfer calculations in vapor flow processes.
  • Investigate the impact of pressure and temperature on phase changes in refrigerants.
USEFUL FOR

Students studying thermodynamics, engineers working with refrigeration systems, and professionals involved in heat transfer calculations in mechanical systems.

marquis24
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Homework Statement



A tank A is connected to a cylinder/piston as shown. The tank has a volume of 100 L and contains saturated vapor R-134a at 30˚C. When the valve is cracked open, the vapor slowly flows into the cylinder B. The piston requires a pressure of 200 kPa in the cylinder to raise it. The process ends when the pressure in tank A has fallen to 200 kPa. During the process, heat is transferred with the surroundings such that the R-134a always remains at 30˚C. Calculate the heat transfer for the process. (101.3 kJ)


Homework Equations


E2-E1 = Q - W
Work = Pressure * Change in volume

The Attempt at a Solution


i know that the Temp remains at 30˚C throughout the process
volume = 100 L

My question is i never know where to start with these types of problems
 
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Am I correct in assuming that you have been working with tables? The ones that give all kinds of information about various substances at various states. Such as U, H, v, T...

Is there any way you could take a picture of the problem or scan and upload it?
 
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You need to include a little more information. There are too many different ways to solve these and you still have not answered my question: are you studying tables? If, so what do you know from the tables? If not, what methods have you been using.
 

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