催化裂化烟气轮机叶片表面催化剂沉积结垢的模拟实验与数值研究
发布时间：2019-01-01 08:01
【摘要】：近年来,随着催化裂化工艺条件的不断变化,催化裂化能量回收系统中的烟气轮机叶片结垢的日益加剧,弄清催化剂颗粒在烟气轮机叶片上的结垢机理对后续烟气轮机阻垢技术的开发有至关重要的作用。本文通过理论分析、数值计算和模拟试验的方法对催化剂颗粒在烟气轮机叶片上的结垢情况进行了研究。首先,本文将催化剂颗粒简化为理想弹塑性球体,运用弹塑性力学和碰撞接触理论的相关知识,建立了催化剂颗粒在壁面上的新沉积模型。第二,基于该自建模型,并运用CFD软件Fluent并结合用户自定义函数(User Defined Function,UDF),本文对某厂双级烟气轮机进行了建模和内部气固两相流场的数值计算分析。本文设计了模拟结垢实验,通过一系列手段,保证了模拟实验中催化剂颗粒的受力状态与实际情况一致,从而得出与实际烟气轮机垢样在外貌相似的样品,这比之前的研究前进了一步。基于该实验的数据,本文通过多因素分析法研究了钠、钙、铁、硫四种元素对催化剂结垢的影响,弥补了数值计算不能考虑催化剂颗粒化学特性变化的不足。同时,通过模拟试验,本文进一步定量地研究了温度、颗粒粒径等对结垢的影响,拟合出关系式,从而为数值计算模型提供了重要参数。本文所做工作可为进一步研究催化裂化烟气轮机的阻垢技术提供理论依据和方法指导。研究结果表明:本文所建沉积模型可以较好的与烟机实际运行情况吻合。双级烟机的第一级承担主要的能量转换功能,该双级烟气轮机的静叶叶形参数设计不够合理,应该进行叶形的结构优化设计;催化剂颗粒在叶片上的沉积结垢呈现“U”型规律,在叶片前缘和后缘处颗粒沉积较多,在叶片中部相对较少;钠、钙、铁、硫四种金属元素对催化剂结垢的促进作用从大到小的顺序为:铁、硫、钠、钙;钠元素和硫元素之间存在较为严重的交互作用,在实际操作过程中,应尽量避免这两种金属元素同时存在;随着温度的增大,催化剂结垢的几率增大,两者呈负相关关系,本文拟合出了两者之间的关系式;催化剂颗粒易结垢的粒径范围是:15μm以下及20~25μm之间。
[Abstract]:In recent years, with the continuous change of FCC process conditions, the fouling of flue gas turbine blades in the FCC energy recovery system is becoming more and more serious. It is very important to understand the scaling mechanism of catalyst particles on flue gas turbine blade for the following development of scale inhibition technology of flue gas turbine. In this paper, the scaling of catalyst particles on flue gas turbine blades is studied by theoretical analysis, numerical calculation and simulation test. Firstly, the catalyst particle is simplified as an ideal elastic-plastic sphere, and a new deposition model of catalyst particle on the wall is established by using the knowledge of elastic-plastic mechanics and collision contact theory. Secondly, based on the self-built model, using the CFD software Fluent and the user-defined function (User Defined Function,UDF), the two-stage flue gas turbine in a factory is modeled and the internal gas-solid two-phase flow field is numerically calculated and analyzed. In this paper, a simulated scaling experiment is designed. By means of a series of means, the stress state of the catalyst particle in the simulation experiment is consistent with the actual situation, and the sample with similar appearance to the actual flue gas turbine scale sample is obtained. This is a step forward from previous research. Based on the experimental data, the effects of sodium, calcium, iron and sulfur on the scale of the catalyst were studied by multi-factor analysis, which made up for the deficiency of numerical calculation which could not consider the change of the catalyst particle chemical characteristics. At the same time, the influence of temperature and particle size on scaling is studied quantitatively by simulation experiments, and the relationship is fitted, which provides important parameters for numerical model. The work in this paper can provide theoretical basis and method guidance for further research on scale inhibition technology of FCC flue gas turbine. The results show that the deposition model in this paper is in good agreement with the actual operation of the smoke machine. The first stage of the two-stage smoke turbine has the main function of energy conversion. The design of the static blade shape parameters of the two-stage flue gas turbine is not reasonable, so the structural optimization of the blade should be carried out. The deposition and scaling of catalyst particles on the leaf showed a "U" pattern, and there were more particles in the front and rear edge of the leaf, but less in the middle of the leaf. The effects of sodium, calcium, iron and sulfur on catalyst scaling are as follows: iron, sulfur, sodium, calcium; There is a serious interaction between sodium element and sulfur element. In the process of practical operation, the existence of these two metal elements should be avoided as far as possible. With the increase of temperature, the probability of catalyst scaling increases, and there is a negative correlation between them. In this paper, the relationship between them is fitted. The particle size range of catalyst particles is below 15 渭 m and 20 ~ 25 渭 m.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE96
[Abstract]:In recent years, with the continuous change of FCC process conditions, the fouling of flue gas turbine blades in the FCC energy recovery system is becoming more and more serious. It is very important to understand the scaling mechanism of catalyst particles on flue gas turbine blade for the following development of scale inhibition technology of flue gas turbine. In this paper, the scaling of catalyst particles on flue gas turbine blades is studied by theoretical analysis, numerical calculation and simulation test. Firstly, the catalyst particle is simplified as an ideal elastic-plastic sphere, and a new deposition model of catalyst particle on the wall is established by using the knowledge of elastic-plastic mechanics and collision contact theory. Secondly, based on the self-built model, using the CFD software Fluent and the user-defined function (User Defined Function,UDF), the two-stage flue gas turbine in a factory is modeled and the internal gas-solid two-phase flow field is numerically calculated and analyzed. In this paper, a simulated scaling experiment is designed. By means of a series of means, the stress state of the catalyst particle in the simulation experiment is consistent with the actual situation, and the sample with similar appearance to the actual flue gas turbine scale sample is obtained. This is a step forward from previous research. Based on the experimental data, the effects of sodium, calcium, iron and sulfur on the scale of the catalyst were studied by multi-factor analysis, which made up for the deficiency of numerical calculation which could not consider the change of the catalyst particle chemical characteristics. At the same time, the influence of temperature and particle size on scaling is studied quantitatively by simulation experiments, and the relationship is fitted, which provides important parameters for numerical model. The work in this paper can provide theoretical basis and method guidance for further research on scale inhibition technology of FCC flue gas turbine. The results show that the deposition model in this paper is in good agreement with the actual operation of the smoke machine. The first stage of the two-stage smoke turbine has the main function of energy conversion. The design of the static blade shape parameters of the two-stage flue gas turbine is not reasonable, so the structural optimization of the blade should be carried out. The deposition and scaling of catalyst particles on the leaf showed a "U" pattern, and there were more particles in the front and rear edge of the leaf, but less in the middle of the leaf. The effects of sodium, calcium, iron and sulfur on catalyst scaling are as follows: iron, sulfur, sodium, calcium; There is a serious interaction between sodium element and sulfur element. In the process of practical operation, the existence of these two metal elements should be avoided as far as possible. With the increase of temperature, the probability of catalyst scaling increases, and there is a negative correlation between them. In this paper, the relationship between them is fitted. The particle size range of catalyst particles is below 15 渭 m and 20 ~ 25 渭 m.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE96
【参考文献】
相关期刊论文 前10条
1 许友好;;我国催化裂化工艺技术进展[J];中国科学:化学;2014年01期
2 胡仁波;白锐;赵晋，
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