Page 22 - Advanced Gas Turbine Cycles

Notation xix
(continued)
Symbol Meaning Typical Units
D demand
e maximum efficiency; also equity; also external
E electrical (unit price); also exit from turbine, and
from first turbine stage
fuel
gas
higher (upper, topping), relating to heat supply,
work output
HL between high and lower plants
HR rejection from higher plant
JB Joule-Brayton cycle
i inlet
LIB irreversible Joule-Brayton cycle
k product gas component; also year number (k= 1,2, . . . )
L lower (bottoming), relating to heat supply, work output
LR rejection from lower plant
rnax maximum
min minimum
m mixture
Nu non-useful (heat rejection)
0 outlet
0 overall (efficiency)
P polytropic (efficiency)
P product of combustion
p' product of supplementary combustion
rit rotor inlet temperature
R rational; also reactants
REV reversible (process)
S steam; also state after isentropic compression or
expansion; also surface area (A,)
S state at entry to stack also supplementary heating
T turbine (isentropic efficiency)
U useful (heat delivered)
W water; also maximum specific work
X cross-sectional flow area (Ax)
x. Y states leaving heat exchanger; also states at entry
and exit from component
1, I/, 2, 2'. miscellaneous, refemng to gas states
3, 3/, 4,4', . . . .
0 conceptual environment (ambient state);
also stagnation pressure
superscripts
CR refemng to internal irreversibility
Q refemng to thermal exergy
(associated with heat transfer); also to
lost work due to external irreversibility associated
with heat transfer
rate of (mass flow, heat supply, work output, etc)
new or changed value (e.g. of efficiency)
(continued on next pnge)