Numerical analysis of various schemes for reconstructing the existing dust preparation system when changing the TР-100 steam generator operation from burning anthracite culm to burning gas coal

Abstract

Three schemes for reconstructing the dust preparation system for
the boiler unit TP-100 for burning gas coal with respect to the
explosion safety of the dust system and the stability of the liquid
slag leakage from the tap of the combustion chamber of the
steam generator at a wide load regulation range of 120-200 MW
are studied. These schemes differ by the way of drying solid
fuel. It is shown that at air drying of coal it is not possible to
achieve a high level of explosion safety of the dust system even
when the standard temperature of the air mixture is within 70°C,
nor the unloading of the block below 140 MW, which is less
than the planned range of 120-200 MW, nor a large margin for
drying agent temperature by the condition of condensation of
water vapor. The interval of the boiler load changing of the unit
TP-100 using the gas-air drying scheme for coal is considerably
narrower than in the case of air drying. This is due to a decrease
in gas temperatures at the outlet from the zone of maximum heat
release and liquid slag, О2 concentration in the gas, and the burnout
efficiency of solid fuel due to the discharge of spent drying
agent loading with inert gases into the main burners. However,
the degree of explosion safety of the dust system (О2 (by
volume) < 16%) and the temperature margin of the drying agent
by the condition of water vapor condensation at air-gas drying is
higher than that of air one. Of the three proposed options for
reconstructing the dust preparation system of the boiler unit TP-
100, the most efficient is the scheme for drying coal with flue
gases and discharging the drying agent into the cooled zone. This
scheme allows to organize a regime of stable liquidл slag
removal within the planned interval of load regulation of the
boiler unit TP-100 of 120-200 MW due to the following
measures: a) the thermal energy of the air is not consumed to
evaporate the moisture of the raw coal; b) dry coal is fed to the
zone of maximum heat release and inert gases are introduced
into it; c) a high degree purification from the dust in the spent
drying agent is provided. A high level of explosion safety of the
dust system is achieved by a low oxygen content in the drying
agent (О2 < 10%). The proposed measures allow exceeding the
temperature of liquid slag above the temperature of normal
liquid ash removal at 113°C, which is much higher than at the air
and gas-air drying. This margin provides stable liquid

Author Biography

B. Rokhman, Coal Energy Technology Institute NAS of Ukraine

rokhman_bb1.jpg

Information about the author: the leading researcher of the Institute of Coal Energy Technologies of the NAS of Ukraine, Doctor of Technical Sciences. Biographical information of Rohman B.B. is published in well-known world directories "Who's Who in Science and Engineering" and "2000 Outstanding Intellectuals of the 21st Century".

Education: Novocherkassk Polytechnic Institute.

Research interests: Mathematical modeling of aerodynamics, heat and mass transfer and chemical reaction of a polydisperse ensemble of solid fuel in a chamber and layer furnaces, in reactors with a circulating fluidized bed and in the fluidized bed. Publications: more than 90 scientific papers, 27 of them are contained in the science-based Scopus database and 4 in the science-based Web of Science database.

References

1. Kuznetsov N.V., Mitor V.V. et al. Thermal calculation of
boiler units (Normative method) – M.: Energia, 1973. – 296 p.
2. Sokolov NV, Kiselgoff M.L. Calculation, and design of
pulverizing units of boilers (Normative materials) – L.: ONTI
CKTI, 1971. – 313 p.
3. Instruction for explosion safety of fuel supply and units
for the preparation and combustion of pulverized fuel (СО 153-
34.03.352-2003) No. 251, 2003. – 19 p.
4. The rules of technical operation of electric power stations
and networks № 296 (ГКД 34.20.507-2003), 2003. – 477 p.

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Published
2017-06-14
How to Cite
Rokhman, B. (2017). Numerical analysis of various schemes for reconstructing the existing dust preparation system when changing the TР-100 steam generator operation from burning anthracite culm to burning gas coal. Vidnovluvana Energetika, (2 (49), 6-16. Retrieved from https://ve.org.ua/index.php/journal/article/view/47
Section
Complex Problems of Power Systems Based on Renewable Energy Sources