用计算法展开圆筒上的接管

本文介绍用计算法解决圆向下上接管（中心线在同一平面上的垂直接管、斜交接管，中心线异面的垂直接管、斜交接管）的展开放样问题。     

储气罐开孔接管处疲劳强度分析

储气罐承受交变内压作用,与罐体内其他开孔接管处相比较,开孔处的开孔率最高,应力集中现象最为显著,发生疲劳破坏的机会也最大,故对储气罐的入孔处进行疲劳强度分析非常重要,文章首先分析了储气罐入孔接口处疲劳产生的原因,其次分析了减少储气罐入孔处疲劳强度的相关策略。     

大型设备现场开孔放样新技术

以大连石化公司350万t/a催化裂化装置再生器为例,以常规投影展开放样理论为基础,详细介绍简易划规法、数学模型法和AutoCAD(计算机辅助)作图放样法等开孔放样新技术,并对这几种方法的优缺点和适用范围进行分析。实践证明这几种开孔放样方法,不仅简便实用,而且计算、放样精度高,同时又在很大程度上提高了施工效率,具有一定的推广意义。     

压力容器开孔接管的疲劳分析

对某开孔接管补强结构进行了应力分析和疲劳分析,并与JB/T4732-95中应力指数法的分析结果对比后可知,用应力指数法得出的疲劳寿命偏于保守。     

大型球罐接管开孔补强的探讨

分析计算了球壳接管区应力集中及补强相关应力集中衰减范围。发现对于大型球壳接管结构 ,连接区内补强相关应力集中衰减宽度在一定的开孔率及球壳半径厚度比范围内超出了GB1 5 0 1 998规定的有效补强宽度。此参数范围内 ,如进行补强设计 ,建议适当增大有效补强宽度。     

内压简体开孔接管结构应力集中系数预测

针对内压筒体平齐式大开孔率开孔接管结构，提出一种基于有限元解的有效的应力集中系数（SCF）估算的经验公式。认为应力集中系数是A=d／√DT，n=T／D和ζ=（Dt）/（dT）函数，对近100个不同尺寸规格开孔接管结构的应力集中系数进行了较详细三维有限元分析计算，采用最小二乘法对应力集中系数规律进行了回归分析，得到了应力集中系数计算的经验公式，另外用83个开孔接管结构的有限元解与其进行了对比计算。结果表明，此经验公式的计算精度可以满足一般工程问题的要求。     

内压简体开孔接管结构应力集中系数预测

针对内压简体平齐式大开孔率开孔接管结构，提出一种基于有限元解的应力集中系数（SCF）估算的经验公式，认为应力集中系数是λ=d/√DT，η=T／D和ζ=Dt／（dT）函数。对近120个不同尺寸规格开孔接管结构的应力集中系数进行了较详细的三雏有限元分析计算，采用最小二乘法对应力集中系数规律进行了回归分析，得到了应力集中系数计算的经验金式，另外用83个开孔接管结构的有限元解与其进行了对比计算。结果表明，此经验公式的计算精度可以满足一般工程问题的要求。     

用AutoCAD绘制球封头开孔放样图

本文以焦炭塔球形封头开孔放样为例,介绍了球形封头开孔放样的原理、方法,并着重介绍了如何使用CAD绘制、输出放样图。将CAD引入到放样领域,可以达到方便快捷、精确简单,从而提出了放样技术的新思路。     

压力容器开孔接管区应力的有限元分析

为了满足工艺过程的要求,压力容器必须开孔接管,从而使开孔接管区的应力状态非常复杂,成为压力容器的高应力区之一。论文采用ANSYS Workbench软件对压力容器筒体上正交接管和切向接管的应力进行了分析比较。结果表明:筒体上正交开孔接管的最大应力强度比切向相同内径的开孔接管的要小。     

计算机辅助汽油调合设计

引言 汽油调合是炼油生产的重要环节,由于汽油是炼油厂的主要产品,调合结果对炼油厂的经济效益影响甚大,因此,炼油企业均希望通过对调合汽油的生产优化获取更多的利润.     

Online process monitoring for complex systems with dynamic weighted principal component analysis☆

Conventional multivariate statistical methods for process monitoring may not be suitable for dynamic processes since they usually rely on assumptions such as time invariance or uncorrelation. We are therefore motivated to propose a new monitoring method by compensating the principal component analysis with a weight approach. The proposed monitor consists of two tiers. The first tier uses the principal component analysis method to extract cross-correlation structure among process data, expressed by independent components. The second tier estimates auto-correlation structure among the extracted components as auto-regressive models. It is therefore named a dynamic weighted principal component analysis with hybrid correlation structure. The essential of the proposed method is to incorporate a weight approach into principal component analysis to construct two new subspaces, namely the important component subspace and the residual subspace, and two new statistics are de-fined to monitor them respectively. Through computing the weight values upon a new observation, the proposed method increases the weights along directions of components that have large estimation errors while reduces the influences of other directions. The rationale behind comes from the observations that the fault information is associated with online estimation errors of auto-regressive models. The proposed monitoring method is exem-plified by the Tennessee Eastman process. The monitoring results show that the proposed method outperforms conventional principal component analysis, dynamic principal component analysis and dynamic latent variable. ? 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.     

Computer aided product design tool for sustainable product development

A computer aided product design (CAPD) tool is proposed that finds mixtures matching target properties. Genetic algorithm crossover and mutation operators are completed with insertion or deletion operators adapted for side branches. A new substitution operator is devised for cyclic molecules. The mixture fitness is evaluated by a weighted sum of property performances. Molecules are represented by molecular graphs. They are split into molecular fragments which are built from polyatomic groups. Molecules or molecular fragments can be fixed, constrained or left free for building a new molecule. Building blocks are chemical functional groups or bio-sourced synthons. A specific coding of hydrogen-suppressed atoms is devised that can be used with various property estimation models where atom connectivity information is required. Illustration is provided through three case studies to find levulinic, glycerol and bio-based derivatives as substitute for chlorinated paraffin, methyl p-coumarate ester solvent and blanket wash solvent, respectively.     

计算机辅选水处理实验室常规配水方案

采用计算机科学计算语言Fortran77，基于目前主流操作系统Win97/98/2000环境，结合利用现代办公套装软件Office97/2000，完成了一种水处理试验中实验室常规配水的计算机可视化界面方案辅选程序软件。运用调试结果显示，该程序软件操作简便、结果合理、可以使用。     

Computer simulation of thermoforming in complex shapes

A finite element analysis of thermoforming based on the thin membrane approximation is presented. Triangular elements with adaptive mesh refinement are used to describe deformed shapes in complex geometries. Viscoelastic effects are assumed to be negligible, and Ogden's model is used to express the material response. The results are in good agreement with previous simulations and some experimental data available in the literature. The combination of adaptive mesh refinement near corners and edges, inclusion of slip or no-slip conditions as required on mold walls, and an efficient equation solver allow simulation of thermoforming in complex geometrical shapes at reasonable computer times on a personal computer.     

A polymer complex as a new type of electron beam resist for dry development

Polymer complex of poly (4-vinylpyrldine) and malonic acid was investigated as a new type of electron beam (EB) resist for dry development, as malonic acid was decomposed by EB irradiation. It was found that the polymer complex could be developed with O₂ plasma etching and that the positive resist patterns with high resolution could be obtained. The mechanism for this lithography process was studied by means of IR and ESCA spectra.     

Development of a catalytically assisted combustor for a gas turbine

A catalytically assisted low NO_x combustor has been developed which has the advantage of catalyst durability. This combustor is composed of a burner section and a premixed combustion section behind the burner section. The burner system consists of six catalytic combustor segments and six premixing nozzles, which are arranged alternately and in parallel. Fuel flow rate for the catalysts and the premixing nozzles are controlled independently. The catalytic combustion temperature is maintained under 1000°C, additional premixed gas is injected from the premixing nozzles into the catalytic combustion gas, and lean premixed combustion at 1300°C is carried out in the premixed combustion section. This system was designed to avoid catalytic deactivation at high temperature and thermal or mechanical shock fracture of the honeycomb monolith. In order to maintain the catalyst temperature under 1000°C, the combustion characteristics of catalysts at high pressure were investigated using a bench scale reactor and an improved catalyst was selected for the combustor test. A combustor for a 20 MW class multi-can type gas turbine was designed and tested under high pressure conditions using LNG fuel. Measurements of NO_x, CO and unburned hydrocarbon were made and other measurements were made to evaluate combustor performance under various combustion temperatures and pressures. As a result of the tests, it was proved that NO_x emission was lower than 10 ppm converted at 16% O₂, combustion efficiency was almost 100% at 1300°C of combustor outlet temperature and 13.5 ata of combustor inlet pressure.     

Rapid process refinement for the development of complex solution copolymers

The industrial manufacture of specialty free radical solution copolymers (FRPs) requires use of a variety of solvents and co-monomers based on the desired properties and end-use. The polymer composition, polymerization solvent, and process parameters have a significant impact on polymer properties such as copolymer composition and polymer molecular weight distribution (MWD). The scale-up and trouble-shooting of copolymerization processes is a significant challenge for the specialty polymers industry due to short project time-scales, limited resources available for each project, and the use of newly developed proprietary monomers. We present approaches that combine process systems and experimental approaches to support data and knowledge-based decisions in the context of live projects under commercial time constraints with only limited data available. These approaches are used for the evaluation and improvement of a batch process operating under reflux conditions that exhibits a large change in solvent boiling point due to the use of high boiling monomers. The approaches allow rapid process refinement and include thermodynamics and heat transfer considerations decoupled from the complexity of reaction kinetics and chemistry with assumptions on heat release rates. Controllability analysis can be carried out at different stages of the batch, sensitivity to the selected solvent tested, and recommendations made on solvent use and process conditions. In addition, we also present an innovative, sparse matrix-based representation of chain length dependent rates that has potential to deliver rapid solutions without loss of detail of MWD.     

Test results of a catalytically assisted combustor for a gas turbine

A catalytically assisted ceramic combustor for a gas turbine was designed and tested to achieve low NO_x emissions. This combustor is composed of a burner and a ceramic liner. The burner consists of an annular preburner, six catalytic combustor segments and six premixing nozzles, which are arranged in parallel and alternately. In this combustor system, catalytic combustion temperature is controlled under 1000 °C, premixed gas is injected from the premixing nozzles to the catalytic combustion gas and lean premixed combustion over 1300 °C is carried out in the ceramic liner. This system was designed to avoid catalyst deactivation at high temperature and thermal shock fracture of the ceramic honeycomb monolith of the catalyst. A 1 MW class combustor was tested using LNG fuel. Firstly, NO_x emissions from the preburner were investigated under various pressure conditions. Secondly, two sets of honeycomb cell density catalysts and one set of thermally pretreated catalysts ware applied to the combustor, and combustion tests were carried out under various pressure conditions. As a result, it was found that the main source of NO_x was the preburner, and total NO_x emissions from the combustor were approximately 4 ppm (at 16% O₂) at an adiabatic combustion temperature of 1350 °C and combustor inlet pressure of 1.33 MPa.