| THERMAL ENGINEERING |
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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 |
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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.
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| Keywords
gasification method
coal hydrogasification
numerical simulation
entrained flow
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Online First Date: 21 October 2015
Issue Date: 15 October 2015
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2015,
Vol. 55
