Optimization and Engineering Application toward Energy Saving for Flue Gas Ducts in Large Coal-Fired Power Plants

doi:10.11930/j.issn.1004-9649.201807042

Abstract

Abstract: To explore the mechanism of flue gas duct optimization for large coal-fired power plants, by virtue of numerical simulation, the flow fields of a square and a circular cross-section flue gas duct model are calculated and analyzed respectively. The result indicates that, there exists an obvious tail flow eddy zone behind the inner supports in the square cross-section flue gas duct, and the effective flow area of the straight duct is merely 79% of the total cross-section area after the flow is stabilized. The outlet velocity deviation is 0.209 in the square straight duct and 0.246 in the square bend, which shows substantial pressure losses. However, the outlet velocity deviation of the circular flue gas duct is 0.052 in the straight duct and 0.146 in the bend, which means that the flow separation is alleviated in the circular cross-section flue gas duct. Moreover, compared with the square cross-section flue gas duct, the pressure losses are lowered down by more than 60 percent. The numerical calculation of the flue gas duct reconstruction project of a 300 MW power plant shows that after the replacement of original square flue gas ducts with the circular ones and the overall layout optimization, the flue resistance has been decreased by 74.6% and the evenness of the flow fields has been improved. Therefore, great economic benefits have been achieved through the reconstruction project.

Key words: thermal power plant, flue optimization, deep power down technology, numerical calculation, circular-section flue gas duct

CLC Number:

TM621.7⁺3

LI Haoran, XU Yongfeng, MA Xiang. Optimization and Engineering Application toward Energy Saving for Flue Gas Ducts in Large Coal-Fired Power Plants[J]. Electric Power, 2019, 52(7): 123-131.

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URL: https://www.electricpower.com.cn/EN/10.11930/j.issn.1004-9649.201807042

https://www.electricpower.com.cn/EN/Y2019/V52/I7/123

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