Analysis of the bottom part of a large technical scale circulating fluidized bed boiler

• Autorzy: Sekret W. , Nowak W.
• Języki publikacji: EN

Abstrakty

EN

An analysis of bed material particle behavior in the bottom part of the combustion chamber of a circulating fluidized bed (CFB) boiler in a large technical scale was undertaken in the study. The tests were carried out on two 670 MW boilers. These boilers differed in the construction of the primary air nozzles. The obtained results have shown the presence of a turbulent bubbling bed in the bottom region of the CFB boiler structure in a large technical scale. It has also been obseryed that in the case of large technical scale CFB boilers a considerable vertical and horizontal pressure gradients occur in the primary air grid region. These lead, on the one hand, to blowing of the bed material into the nozzle discharge channels and possibly a backflow to the windbox and, on the other hand, to a non-uniform fluidization of the bottom region. The tests have also demonstrated a strong effect of the primary air nozzle design on the NO[x] concentration in the combustion gas.

Słowa kluczowe

EN

air nozzles; bottom region; fluidized bed; NOx concentration

PL

dysza powietrzna; złoże fluidalne

• Wydawca: Wydawnictwo Instytutu Maszyn Przepływowych PAN ; Komitet Termodynamiki i Spalania PAN
• Czasopismo: Archives of Thermodynamics
• Rocznik: 2006
• Tom: Vol. 27, no. 1
• Strony: 31--52
• Opis fizyczny: Il., wykr., rys., wz.,Bibliogr. 18 poz.,

Twórcy

autor

Sekret W.

autor

Nowak W.

• Wydział Inżynierii i Ochrony Środowiska, Politechnika Częstochowska, ul. Dąbrowskiego 73, 42-200 Częstochowa

Bibliografia

• [1] HARTGE E., RENESNER D., WERTHER J.: Solids concentration and velocity patterns in circulating fluidized beds, Circulating Fluidized Bed Technology II (edited by Basu P., Largo J.), 1988, 165-180.
• [2] HORIO M.: Hydrodynamics Circulating Fluidized Bed (edited by Grace J., Avidan A., Knowlton T.), 1997, 21-85.
• [3]MUSKAŁA W.: The comprehensive study of binary circulating fluidized bed BCMF used in the clean energy production, monograph No 75, Częstochowa University of Technology, 2001.
• [4] NOWAK W.: Comprehensive Study of Circulating Fluidized Bed, monograph No 9, Częstochowa University of Technology, 1989.
• [5] KUNI D., LEVENSPIEL O.: High- Velocity Fluidization, Fluidization Engineering (ed. by Kunii D., Levenspiel O.), II ed., 1991, 195-206.
• [6] KUNI D., LEVENSPIEL O.: Fluidization and mapping of regimes, Fluidization Engineering (ed. by Kunii D., Levenspiel O.), II ed., 1991, 85-88.
• [7] SENIOR R., BRERETON C.: Modeling of circulating fluidized bed solids flow and distribution, Chemical Engineering Science, 47, 1992, 281-296.
• [8] SEKRET R., NOWAK W.: Emissions of gaseous pollutants from large scale circulating fluidezed boilers, Proc. of Conference on Fluidized Bed Coal Combustion, Złotniki Lubańskie, 22-24 April, 2004, 242-252.
• [9] SEKRET R., NOWAK W.: A circulating fluidized bed structure of large scale boiler, Chemical and Process Engineering, 25, 2004, 2291-2298.
• [10] SEKRET R.: Distribution of solids concentration and fluctuation of pressure in large-scale a circulating fluidized bed boiler, Gospodarka Paliwami i Energią, No 9, 2003, 10-16 (in Polish).
• [11] SEKRET R., NOWAK W.: Particles segregation in circulating fluidized bed structure of large-scale boiler, Chemical and Process Engineering, 25, 2004, 2283-2290.
• [12] VAN DER SCHAAF J., JOHNSSON F., SCHOUTEN J.C, VAN DEN BLEEK C.M.: Fourier analysis of nonlinear pressure fluctuations in gas-solids flow in CFB risers - Observing solids structures and gas/particle turbulence, Chemical Eng. Sci., 54, 1999, 5541-5546.
• [13] SEKRET R., NOWAK W.: Segregation of fuel particles in a circulating fluidized bed, Chemical and Process Engineering, 23, 2002, 229-244.
• [14] SVENSSON A., JOHNSSON F., LECKNER B.: Fluid-dynamics of the bottom bed of circulating fluidized bed boilers, Proc. 12m Int. Conf. on Fluidized Bed Combustion, eds. Rubow L. N. and Commonwealth, ASME, 1993, 887-897.
• [15] MIREK P., MIREK J. SEKRET R., NOWAK W.: Nozzles in CFB boilers, Circulating Fluidized Bed Technology VIII, Intern. Academic Publishers, World Publ. Co., ed. Kefa Cen, 2005, 877-883.
• [16] JOHNSSON F., SVENSSON A., ANDERSSON S., LECKNER B.: Fluidization regimes in boilers, Fluidization VIII, Tours, May 1995, 14-19.
• [17] JOHNSSON F., SVENSSON A., LECKNER B.: Fluidization regimes in circulating fluidized bed boilers, Fluidization VII, eds. Potter O.P. and Nicklin D. J., Eng. Foundation Conf., Brisbane, 1992, 471-478.
• [18] JOHNSSON F., ZIJERVELD R.C., LECKNER B.: Air-plenum pressure fluctuations in a circulating fluidized bed boiler, Proc. 2nd European Conf. on CFB, eds. Olazar M., San José M.J., University of Basque Press Service, Bilbao, 1997, 223-230.