A numerical study on parametric sensitivity of the flow characteristics on pulverized coal gasification

✍ Scribed by Han Chang Cho

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 150 KB
• Volume: 24
• Category: Article
• ISSN: 0363-907X
• DOI: 10.1002/(sici)1099-114x(200005)24:6<511::aid-er600>3.0.co;2-m

✦ Synopsis

In order to analyse the sensitivity on pulverized coal #ames of variables such as initial turbulent intensity, steam addition, primary/secondary momentum ratio, and radiation heat transfer, a numerical study was conducted at the gasi"cation process. Eulerian approach is used for the gas phase, whereas Lagrangian approach is used for the solid phase. Turbulence is modeled using the standard k} model. The turbulent combustion model incorporates the eddy dissipation model. The radiation heat transfer is solved using a Monte-Carlo method. One-step two-reaction model is employed for the devolatilization of a Kideco coal.

In pulverized #ame of long lifto! height, the initial turbulent intensity is an important factor to predict the accurate #ame front position. The radiation heat transfer and wall heat loss ratio distort the temperature distributions along the reactor wall, but do not a!ect the reactor performance such as coal burnout, residence time and #ame front position. The primary/secondary momentum ratio only a!ects the position of #ame front, but the coal burnout is slightly in#uenced. It is con"rmed that the momentum ratio is a variable only associated with the #ame stabilization. The addition of steam in the reactor has a detrimental e!ect on all the aspects, particularly in reactor temperature and coal burnout. The increase of lifto! height and dropped gas temperature mean the harm of #ame stabilization in the reactor, and so the gasi"cation reaction may be deactivated.