QQ客服 官方微博 反馈留言

题名	固体生物质气化器数学模型的研究
作者	黄海涛
学位类别	硕士
答辩日期	1990
授予单位	中国科学院广州能源研究所
授予地点	中国科学院广州能源研究所
导师	徐冰燕
学位专业	热能工程
中文摘要	To improve the design and operation of a biomass gasifier, mathematical modelling is important and helpful. In this dissertation, the physical and chemical processes occuring in the gasifier are investigated, Three models for different proto-types and purposes are formulated. Balance Model: Chemical equilibrium is assumed in this model. The equilibrium compositions and adiabatic flame temperature are calculated by "equilibrium constant method" and "mass and energy balance". The simple algorithm can get convergence rapidly. Using this model, air, steam, oxygen, hydro and steam-external-heat-supplied gasification are studied under different operational conditions. One-Dimensional model for Circulating-Fluidized Bed Gasifier: The model is a combination of "balance model" and "Kinetic model". In the char oxidation zone, which is composed of circulating char and hot sand, balance model mentioned above is used to calculate the temperature and gas compositions. In the pyrolysis-reduction zone, kinetic model is developed, which incorporates mass and energy convervation, kinetics of wood fast pyrolysis, char reduction and water-gas shift reaction. The model can be used to predict the necessary dimensions for this kind of gasifier. One-Dimensional model for Up-Draft Gasifier: The important processes considered are conventive heat and mass transfer between gas and solid phase, heat conduction of the solid phase, kinetics of wood slow pyrolysis, char reduction, char oxidation and has phase reactions. The conduction term in the energy equation has empirically accounted for particle-particle radiative heat transfer by "effective thermal conductivity" of the solid phase. In the high-temperature packed-bed reactor, where gas and solid flow rate is low, the conductive and radiactive heat transfer may be as important as conventive heat transfer. The overlooking of these processes will cause numerical stiffness of the differantional equations describing mass and energy conservation. The set of second-order, non-linear differentional equations and auxiliary algebraic equations are integrated along the reactor height, yielding the temperature profile, gas composition and carbon conversion profile. Gas and solid phase residence time are also calculated.
语种	中文
公开日期	2011-07-06 ; 2011-07-08
页码	58
内容类型	学位论文
源URL	[http://ir.giec.ac.cn/handle/344007/3883]
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	黄海涛. 固体生物质气化器数学模型的研究[D]. 中国科学院广州能源研究所. 中国科学院广州能源研究所. 1990.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。