A vertical piston-cylinder device initially contains 0.12 m3 of helium at 208C. The mass of the piston is such that it maintains a constant pressure of 200 kPa inside. A valve is now opened, and helium is allowed to escape until the volume inside the cylinder is decreased by one-half. Heat transfer takes place between the helium and its surroundings at 208C and 95 kPa so that the temperature of helium in the cylinder remains constant. Determine (a) the maximum work potential of the helium at the initial state and (b) the exergy destroyed during this process.

Transcribed Image Text:

Surroundings 20 C 95 kPa Hlium 0.12 0 20 c 200 kPa FIGURE P8-77