【作者】 毛娅；

【导师】 陈定方； 陈作炳；

【作者基本信息】 武汉理工大学 ， 机械制造及自动化， 2008， 博士

【摘要】 针对我国建材工业虽然规模大,但存在生产过程能耗高,资源消耗大,环境污染严重等问题。本博士学位文以2500t/d强化悬浮式分解炉（ReinforeedSuspension Precalciner,RSP）为研究对象,通过基于虚拟样机的技术对该分解炉炉内热工过程进行了数字化模拟。预分解新型干法水泥生产技术是目前水泥生产的最先进的技术,分解炉是新型干法水泥生产线上预分解技术的核心设备和关键技术装备之一,其性能优劣直接影响到系统能耗、环保排放以及整个系统的生产效率。虚拟样机（Virtual Prototyping,VP）技术是一种基于虚拟样机的数字化设计方法,通过搭建分解炉虚拟样机,可以对分解炉内部的热工过程进行全方位的模拟,为后继的分解炉优化设计提供一个便捷、直观的计算机辅助设计平台。分解炉系统内部的流场非常复杂,燃料燃烧和生料分解这两个反应是悬浮于气流中进行的,各过程相互制约。以计算流体力学（Computational FluidDynamies,CFD）为理论基础的数值模拟技术能对流动、传热、燃烧、化学反应、多相流等问题进行准确的预测,并在许多工程领域得到验证和推广。计算机流体力学的迅速发展及在工业领域的应用,为描述分解炉燃烧过程以及窑炉结构优化设计和应用提供了良好的手段。本文以2500t/d RSP型分解炉为例,通过冷模试验,测试出分解炉内部流场的基本数据和特征,采用k-ε双方程湍流模型对气相流场进行模拟。对炉内生料及煤粉颗粒的运动采用随机颗粒轨道模型进行模拟。对煤粉的燃烧模拟采用非预混燃烧模型,挥发模型采用Kobayashi模型,燃烧的辐射传热采用P-l模型,碳粒燃烧采用反应动力/有限扩散速率模型,煤粉燃烧化学反应模型采用混合分数/PDF（概率密度函数）模型。本文对分解炉内部速度场、温度场、组分浓度场进行了模拟,并在此基础上采用收缩圆柱体以及收缩球状模型对生料CaCO₃分解率进行了计算。模拟结果得到了炉内气体流动状态、颗粒运动规律、煤粉燃烧状态等多项参数,全面精细直观地反应了炉内的流动状态。模拟结果符合炉内的流动趋势,为分析强化悬浮式分解炉内的流动规律和化学反应提供了有效信息,亦为分解炉的结构优化和实际操作参数的选取提供了重要的理论依据。石油焦作为石化行业所生产的副产品,其含碳量高、含灰量少,具有较高的热值,用其作为一种替代燃料,可以缓解能源短缺的矛盾,在高耗能的水泥生产中采用石油焦为燃料具有很大的市场前景。本文在对石油焦燃烧物化特性进行了定量分析实验的基础上,通过数值模拟的方法,对石油焦在分解炉内燃烧过程进行了数字化模拟,结果表明,RSP型分解炉结构既有利于物料的继续加热分解又有利于延长物料及燃料在炉内的停留时间。因此,这种炉型适用于石油焦的完全燃烧。随着人们对环境保护的日益重视,国际上对水泥行业氮氧化物（NOx）的排放的规定越来越严格,本文对分解炉内氮氧化物生成的机理进行的深入的探讨,在对热力型NOx和燃料型NOx生成的模拟中考虑湍流的影响,时均湍流反应速率的求解采用随机密度函数（PDF）方法。模拟结果预测了分解炉内NOx分布的浓度情况,并根据模拟结果提出了针对RSP型分解炉降低NOx排放的措施。更多还原

【Abstract】 According to the fact that although the building material manufacturing industry is large in scale, but it has problems of high energy consumption and pollution. In this thesis, a reinforced suspension precalciner of 2500t/d is taken as an example to simulate its internal working process based on virtual prototyping technology.Virtual prototyping technology is a digital design method base on virtual prototype. By build the virtual prototype of calciner, the internal working process can be simulated in all respects and provide a convenient and intuitionistic CAD plat for optimization of calciner design.The flow field in precalciner system is very complex as well as the reactions of fuel combustion and raw materials decomposing, which are influenced by each other and taken place in suspension of the air flow. The simulation technology based on computational fluid dynamics (CFD) can accurately predict the flow, heat transfer, combustion, chemical reaction and multiple phase flow. It is also a good method to predict the internal process in calcnier.In this thesis, a numerical model is presented of the flow and transport processes taking place in an industrial RSP calciner of 2500t/d. First, it’s the feature of its internal flow field is measured by cold model test. According to the results of cold model test, the flow field is simulated by k-εtwo equation turbulence models. Movement of raw material and coal particle is simulated by the particle stochastic trajectory model. This model is capable in simulating particle with complicated experience. It also enables to simulate coupling interaction between gas phase and particle phase, turbulence diffusion of particle is also regarded in this model. Non-premixed combustion model is adopted in simulating coal combustion; the model of Kobayashi is used for devolatilization model; radiation of the combustion is expressed with the P-1 radiation model and kinetic/limited diffusion rate model is adopted for char combustion. The method of probability density function (mixture fraction/PDF) is used for the chemical reaction models in coal combustion. In this way, the distributions of fluid velocities, temperatures and concentrations of the reactants and products as well as the trajectories of particles and their interaction with the gas phase are calculated. On the base of these results the calcination rate can be determined by contractive cylinder and sphere model.The simulating result predicts the flow field, the particle movement and the coal combustion, which is coincident with the flow tendency. The result provides useful information for analyzing the kinetics regulation and reaction in precalciner, and also allow estimations to be made and conclusions to be drawn that help in the optimization of a given calciner.Petroleum coke is the main byproduct of the oil refining industry. It is regarded as an economical alternative fuel for the pulverized coal in high energy consumption cement production. The present article is devoted to introduce the research works on make use of petroleum coke as a substitutional fuel of calciner, which consists of two major parts. In the first part, the basic properties of the petroleum coke and its characteristics of grindability, devolatilization, ignition and combustion were investigated by serials of experiment. And in the second part, a numerical model was also presented to simulate the combustion processes taking place in an industrial reinforced suspension calciner. The results of study show that petroleum coke is a suitable fuel for RSP calciner.As the environment protection is held in high regard today, the regulation for the NOx emission for cement industry is much stricter. In this thesis, the mechanism of NOx generation is deeply discussed. In the simulation of thermal NOx and fuel NOx, the influence of turbulence is taken into consideration and time-mean reaction rate is solved by probability density function (PDF) method. The simulation result can predict the distribution of the NOx in the calciner and the measure to reduce the NOx emission is put forward for RSP calciner.更多还原