Page 204 - Advanced Gas Turbine Cycles

Chapter 9. The gas turbine as a cogeneration (combined hear and power) plant 169
Fj = FCG = 4

[a] COGENERATION
PLANT WITH WASTE
"Q" = 3 HEAT RECUPERATOR

(QU)CG 12.25 +j?

4 (QNU)CG 0.75

[b] COGENERATION
PLANT WITH WASTE
"QI3 HEAT BOILER

T=6

Qu =7.2

1.8
QNU
Fig. 9.2. Cogeneration plants (a) with waste heat recuperator (WHR) and (h) with waste heat boiler (WHB).
factor is thus not entirely satisfactory as a criterion of performance as it gives equal weight
to W and QU. A 'value-weighted' EUF is therefore sometimes used, accounting for the
different pricing of electrical power and heat load. If the sale price of electrical power is YE
(EkWh), that of the heat load is YH (UkWh) and the price of fuel is 6 (EkWh) then the
'value-weighted' EUF can be calculated as

(9.3)