Knowledge Management System Of Guangzhou Institute of Energy Conversion, CAS
| 固体生物质气化器数学模型的研究 | |
| 黄海涛 | |
| Thesis Advisor | 徐冰燕 |
| 1990 | |
| Degree Grantor | 中国科学院广州能源研究所 |
| Place of Conferral | 中国科学院广州能源研究所 |
| Degree Name | 硕士 |
| Degree Discipline | 热能工程 |
| Abstract | 本文应用固体生物质热化学转换基础理论研究的知识，结合化学热力学、化学动力学、流动与混合、传热与传质的有关知识，建立了固体生物质气化器的平衡模型、载汉床气化器一维数学模型和固定床气化器一维数学模型，应用上述模型，研究了各种气化方案的运行条件和气化效果，分析计算了载流床气化器和固定床气化器的合适的气化器尺寸，模型的建立对于发展固体生物质气化器的设计理论有重要的意义。 |
| Other Abstract | 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. |
| Pages | 58 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.giec.ac.cn/handle/344007/3883 |
| Collection | 中国科学院广州能源研究所 |
| Recommended Citation 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. |
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