Fall 1999, METBD 330 - Thermodynamics

Prof. Dave Johnson, dhj1@psu.edu, Penn State - Erie, The Behrend College


  A piston-cylinder device contains 0.8 m3 of Refrigerant-134a at 320 kPa and 100oC.  The R-134a is now cooled at constant pressure until the temperature drops to 10oC.  Determine the heat transfer.  Sketch the process on a Tv diagram showing the saturation lines.

(Answer:  -750.33 kJ)

 

 

 

 


  An insulated, rigid tank contains 0.5 kg of water in a liquid-vapor mixture at 95oC with a specific volume of 1.1988 m3/kg.  An electric heater inside the tank does work on the water, raising its pressure to 200 kPa.   What is the final temperature of the water ?  How much electrical work was done on the water ?  Sketch the process on a Pv diagram.

(Answers: 250oC, - 531 kJ)