In: Mechanical Engineering
One kg of water in a piston-cylinder assembly,
initially at 1.5 bar and 200 C, cools at constant pressure with no
internal irreversibilities to a final state where the water is a
saturated liquid. For the water as the system, determine the work,
the heat transfer, and the amounts of exergy transfer accompanying
work and heat transfer, each in kJ. Let T0 = 20 °C, p0=1 bar and
ignore the effects of motion and gravity.
THERE ARE SOME DIFFERENT ANSWERS TO THIS QUESTION. I FOUND AN
ANOTHER ANSWER, I HAVE MANY QUESTION MARKS IN MY MIND. ADDITION OF
EXERGY TRANSFER ACCOMPANYING WORK AND HEAT SHOULD BE EQUAL TO
E2-E1. SINCE ITS INTERNALLY REVERSIBLE. ON THE OTHER HAND WHEN I
USE 'E2-E1=(U2-U1)+P0×(V2-V1)-T0(S2-S1)' I FIND AN ANOTHER NUMBER.
PLEASE HELP.