The document discusses calculating net plant heat rate (NPHR) which is used to determine plant efficiency. NPHR takes into account turbine heat rate, boiler efficiency which depends on the type of coal burned (bituminous, subbituminous, lignite), and auxiliary power (unit base + common facility). Plant efficiency is calculated as 860 divided by NPHR. The document also states that boiler efficiency does not depend on boiler design but on the type of coal burned.

1. NETT PLAN HEAT RATE
TurbineHea tRate
NPHR
boiler
(1 % AUXPOW ER )
AUX POWER = UNIT BASE + COMMONFACI LITY
2
PLANT EFFICIENCY = 860 / NPHR
EFFISIENSI BOILER TIDAK TERGANTUNG TERHADAP BOILER DESIGN TETAPI
TERHADAP JENIS BATUBARA YANG DIBAKAR.
EFFISIENSI BOILER MENURUT COAL YANG DIBAKAR
HHV LHV
BITUMIOUS 88,5% 96%
SUBBITUMIOUS 86% 94%
LIGNITE 81-85% 92%