4"12-Z 1 - part - usaid

Flue gas samples were also taken at the two LD. fans to compare readmg to see how much
leakage there was from the air heaters. This umt had the LJunstgrom regeneratIve aIr heaters
replaced wIth tubular heaters during reconstructIOn. All readIngs, includmg oxygen and excess
aIr, mdicated sIgmficant aIr mleakage, probably most from ductwork and precIpItator leaks.
Flue gas samples for block 5 were taken at the same extractIOn points where eXIstIng oxygen
analyzers are connected. These boilers were burning 60% natural gas and 40% mazut, at
95 MW load and reduced steam pressure and temperature. The oxygen levels were hIgh due
to somewhat high excess aIr. The high oxygen readmgs correlated wIth the control room
readings from the existIng extractive oxygen analyzers.
Due to the high m-leakage rates m the furnace, the economIzer and the air heater, an on-lIne
calculatIon of the combustion efficiency by Enerac portable combustIOn analyzer proved to be
not feasible. The efficiency calculated IS actually overall bOIler effiCIency as shown on the
pnntout. Direct measurements of 02' CO, combustible gases, NO x , and S02 appeared to be
accurate. Any improvement in the effiCIency of the Burshtyn power plant must come primarily
from an improvement in overall effiCIency of ItS bOIlers. On the steam SIde the Burshtyn power
plant is effiCIent due to a significant thermal load. A copy of the Enerac portable combustIOn
analyzer print-outs can be seen m AppendIX B.
For a detailed descnptIon of the AudIt actIvitIes, see the trip report m AppendIX G.
Burns and Roe engineers estimated an incremental improvement m boiler effiCIency achievable
due to a reduction in excess aIr fed to the bOIlers. Usmg a portable combustion analyzer, 5-7%
excess furnace oxygen was measured at full load whIle finng coal and 7-10% excess furnace
oxygen at 50% load while finng natural gas. CO emIssions were negligible in both cases.
Based on calculations, the excess furnace oxygen at full load while firing coal can be reduced
by 1% O 2 resulting in an mcremental Improvement m bOIler effiCIency of at least 0.24%.
In future the Burshtyn power plant operators should be able to manually adjust the air supply
to determine what magmtude of reductIOn in excess air could be achieved within constraIns
imposed by CO emiSSIOns, smoke, and flame StabIlIty Therefore, It IS recommended that
permanent instruments be mstalled to measure the O 2 and CO content of the flue gas and thus
assist the operators in aVOIding unsafe conditIOns while contmually minimIZIng excess aIr.
4.1.4 Boiler Plant
Block 12 is now under reconstructIOn mcludmg turbine repaIr, new HP and LP cylinders, and
a new 99% effiCIent RussIan electrostatIC precIpItatOr. The next preCIpitators for block 11 and
block 7 reconstruction m 1995 WIll be UkraIman manufacturer. The bOIler has all cntlcal
pressure parts and membranes replaced and the steam drum checked, WIth an expected 20-25
year lIfe extenSIOn. This will restore the ratmg of block 12 to upgraded 225 MW deSIgn and
wIll be finished in Apnl 1995.
5906-01/02A/BURSHTYN/5/17/95 9