Question

5 kg of steam contained within a piston-cylinder assembly undergoes an expansion from state 1, where the specific internal energy U(1) is = 2710 [kJ/kg] to state 2, where U(2) = 2660 [kJ/kg].

During the process, there is heat transfer to the steam with a magnitude of 80 [kJ]. Also, a paddle wheel transfers energy to the steam by work in the amount of 18.5 [kJ]. Determine the energy transfer by work from the steam to the piston during the process

Answer 1

Five kg of steam undergo and expansion in a piston-cylinder assembly from state 1 to state
2. During the expansion the cylinder is heated with a flame and 80 kJ of heat is transferred
to the steam. There is also a paddle wheel inserted into the cylinder which transfers 18.5 kJ
of work to the steam during the expansion. Internal energy changed from 2709.9 kJ/kg to
2659.6 kJ/kg during the process. Determine the amount of energy transfer by work from the
steam to the piston during the process.