4"12-Z 1 - part - usaid

5.3 Replicatine and Expandine the Proeram to Other Power Plants
An economic benefit can be derived from extending the demonstratIon program to other
Ukrainian Power Plants. From Burns and Roe expenence the UkraInian Power Plants, when
firing coal or coal and mazut, exhIbIt the following typIcal charactenstIcs:
• Ukrainian power plants operate In a steady-state mode (base load),with a turbine
maintaining throttle pressure, "fixed" finng rate, floatIng frequency and manually
adjusted aIr flow (fixed settings for each load).
• Very hIgh in-leakage rates (up to 100%) are typical, WhICh make readings of any
oxygen analyzer dependent on its locatIOn (dIstance from the furnace). They also
make impossible on-line calculation of the combustIOn efficiency at the back end
of the boiler. What IS calculated by the Enerac IS boiler effiCIency.
• Most of the oxygen analyzers are of the extractIve/paramagnetic type, WIth
questIonable accuracy and a measurement tIme constant on the order of about 1-2
mInutes. As a result, they cannot be used for real tIme excess air control.
• Low carbon monoxIde levels (10 to 100 ppm) In the flue gas In combmation with
4 to 5 % oxygen In locatIOns WIth 850-870 Degree CentIgrade temperature leads
us to believe that combustIOn effiCIency of the Ukraiman Power Plants can be
improved. In our estImatIOn, the Improvement will be on the order of 0.5 % to
1%.
The conclusions are as follows:
• Excess aIr can be reduced untIl a maximum of 300-400 ppm of carbon monoxIde
is generated whIch is indIcatIve of effiCIent coal combustIOn.
• ConSIderable economic benefit can be realized by reducIng the excess oxygen by
1-1.25% and achieve 0.5 % Improvement In combustIOn effiCIency even WIth
existIng manual control of the combustIOn process. It is Important that constant
operator attention IS maIntained. Such attentIOn can be obtaIned by way of
operator incentives based on the fuel saVIngs. Another alternatIve would be to
invest in expensive automatic control for the excess air system.
• Savings can be achIeved more easIly WIth carbon monOXIde measurements of the
undIluted flue gas at different boIler loads
• Improvements In boIler effiCIencIes and reductIons In fuel consumptIOn can be
further demonstrated by replIcating and expandIng the portable combustIon
analyzer program to other UkraInian power plants.
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