Numerical simulation of the flow field characteristics in an entrained flow coal hydrogasifier
GUAN Qingliang, BI Dapeng, WU Yuxin, ZHANG Jiansheng
Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China
Abstract：The flow field and reaction processes in a coal hydrogasifier reactor were modeled using a three-dimensional numerical model of Rockwell's 6 t/d entrained flow coal hydrogasifier using the hydropyrolysis kinetic model developed by Johnson and Tran as well as tar hydrocracking reactions. The numerical predictions were in good agreement with experimental results for the 6 t/d hydrogasifier. The simulations show that the flow field in the hydrogasifier can be categorized into a cross-flow impinging region, a jet-reflux flow region, and a plug flow region. The primary devolatilization reactions are complete immediately after the rapid mixing of the hot hydrogen and coal particles. The methane is mainly produced in the cross-flow impinging region and jet-reflux region. Most of the lower hydrogasifier has plug flow. Small particles are heated and lose weight faster in the cross-flow impinging region and jet-reflux flow region, while in the plug flow region, the particle size has minor effect on the particle temperature and mass history.
管清亮, 毕大鹏, 吴玉新, 张建胜. 气流床煤加氢气化反应器的数值模拟及流场特性分析[J]. 清华大学学报（自然科学版）, 2015, 55(10): 1098-1104.
GUAN Qingliang, BI Dapeng, WU Yuxin, ZHANG Jiansheng. Numerical simulation of the flow field characteristics in an entrained flow coal hydrogasifier. Journal of Tsinghua University(Science and Technology), 2015, 55(10): 1098-1104.
[1] Zhang A, Kaiho A, Yasuda H, et al. Fundamental studies on hydrogasification of Taiheiyo coal [J]. Energy, 2005, 30(11/12): 2243-2250.
[2] Friedman J. Development of a Single-Stage, Entrained-Flow, Short-Residence-Time Hydrogasifier [R]. FE-2518-24. Canoga Park, CA, USA: Rockwell International, 1979.
[3] Johnson J L, Tran D Q. Kinetics of Devolatilization and Rapid-Rate Methane Formation [R]. GRI-78/0049. Chicago, IL, USA: Institute of Gas Technology, 1980.
[4] Kalinenko R A, Levitskii A A, Polak L S, et al. Calculation and theoretical investigation of processes occurring in the pyrolysis and hydropyrolysis of coal [J]. Kinetics and Catalysis, 1985, 26(6): 1149-1156.
[5] Sprouse K M. Modeling pulverized coal conversion in entrained flows [J]. AIChE Journal, 1980, 26(6): 964-975.
[6] Goyal A, Gidaspow D. Modeling of entrained flow coal hydropyrolysis reactors. 1: Mathematical formulation and experimental-verification [J]. Industrial & Engineering Chemistry Process Design and Development, 1982, 21(4): 611-624.
[7] Goyal A, Gidaspow D. Modeling of entrained flow coal hydropyrolysis reactors. 2: Reactor design [J]. Industrial & Engineering Chemistry Process Design and Development, 1982, 21(4): 625-632.
[8] Asaoka Y, Azuma T, Kawamoto M, et al. Development of coal hydrogasification technology. 3: Simulation incorporated the hydro-pyrolysis model into computational fluid dynamics [C]// 17th Annual International Pittsburgh Coal Conference. Pittsburgh, PA, USA, 2000.
[9] YAN Linbo, HE Boshu, PEI Xiaohui, et al. Kinetic models for coal hydrogasification and analyses of hydrogasification characteristics in entrained-flow gasifiers [J]. Energy & Fuels, 2013, 27 (11): 6388-6396.
[10] YAN Linbo, HE Boshu, PEI Xiaohui, et al. Computational-fluid-dynamics-based evaluation and optimization of an entrained-flow gasifier potential for coal hydrogasification [J]. Energy & Fuels, 2013, 27(11): 6397-6407.
[11] Grant D M, Pugmire R J, Fletcher T H, et al. Chemical model of coal devolatilization using percolation lattice statistics [J]. Energy & Fuels, 1989, 3(2): 175-186.
[12] Tomita A, Mahajan O P, Walker Jr P L. Reactivity of heat-treated coals in hydrogen [J]. Fuel, 1977, 56(2): 137-144.
[13] Watanabe H, Otaka M. Numerical simulation of coal gasification in entrained flow coal gasifier [J]. Fuel, 2006, 85(12/13): 1935-1943.
[14] Suuberg E M, Peters W A, Howard J B. Product composition and kinetics of lignite pyrolysis [J]. Industrial & Engineering Chemistry Process Design and Development, 1978, 17(1): 37-46.
[15] Greene M I. Engineering development of a short residence time, coal hydropyrolysis process [J]. Fuel Processing Technology, 1978, 1(3): 169-185.
[16] Magnussen B F, Hjertager B H. On mathematical modeling of turbulent combustion with special emphasis on soot formation and combustion [J]. Symposium (International) on Combustion, 1977, 16(1): 719-729.
[17] Graber W D, Huttinger K J. Chemistry of methane formation in hydrogasification of aromatics. 1: Non-substituted aromatics [J]. Fuel, 1982, 61(6): 499-504.
[18] Graber W D, Huttinger K J. Chemistry of methane formation in hydrogasification of aromatics. 2: Aromatics with aliphatic groups [J]. Fuel, 1982, 61(6): 505-509.
[19] Serio M A, Peters W A, Howard J B. Kinetics of vapor-phase secondary reactions of prompt coal pyrolysis tars [J]. Industrial & Engineering Chemistry Research, 1987, 26(9): 1831-1838.
[20] Virk P S, Chambers L E, Woebcke H N. Thermal Hydrogasification of Aromatic Compounds [M]. Massey L G, ed. Coal Gasification. Washington, DC: American Chemical Society, 1974: 237-258.
[21] SUN Zhonghua, DAI Zhenghua, ZHOU Zhijie, et al. Numerical simulation of industrial opposed multiburner coal-water slurry entrained flow gasifier [J]. Industrial & Engineering Chemistry Research, 2012, 51(6): 2560-2569.
2015, Vol. 55 
