Page 41 - Advanced Gas Turbine Cycles

18 Advanced gas turbine cycles
from Eq. (2.17). Thus the work lost due to internal irreversibility within the control volume
when heat transfer takes place is still ToAFR, as when the heat transfer is limited to
exchange with the environment.
The actual work output in a real irreversible process between stable states X and Y is
therefore

T-To
= Bx - By - Jx (-)de - fR EX - EY - - fR, (2.19)
=

where

is the work potential, sometimes called the thermal energy of the heat rejected.
The above analysis has been concerned with heat transfer from the control volume.
Consider next heat [de]: = [dQREV]i transferred to the control volume. Then that heat
could be reversibly pumped to CV (at temperature T) from the atmosphere (at temperature
To) by a reversed Carnot engine. This would require work inpur

Under this new arrangement, Eq. (2.15) for the reversible work delivered from CV would
become

(2.20)

and Eq. (2.19) for the work output from the actual process would be
[Wcvli = (Ex - Ey) + EpN - ICR, (2.21)

where eN the work potential or thermal energy of the heat supplied to CV,
is
T-To
EPN = Jx (-)de.

If heat were both transferred to and rejected from CV, then a combination of Eqs. (2.19)
and (2.21) would give

[w(y]i = (Ex - Ey) + E~N - @UT - fR. (2.22)