焊接热传导方程的有限元解法

采用有限元解法解决非线性问题比较方便而实用的方法。另外随着有限元软件的日益成熟这种方法被越来越多的人所接受。文中首先对有限元方程做了整理和归纳,然后应用有限元分析软件,并考虑到材料的物理性能随温度的变化以及外界环境对焊接构件温度场的影响,对不锈钢平板焊接的热传导过程进行有限元分析。获得了平板焊接过程的温度场的分布情况。     

基于数值模拟的塑料薄板拉伸成形研究

利用有限元软件为塑料薄板双向拉伸成形过程建立了有限元计算模型 ,并进行了计算和分析 ,将原用于结构计算的有限元软件引用于薄膜成形工艺领域。文中深入研究了从管坯到薄膜吹胀成型过程中的厚度分布变化和半径分布变化 ,并给出了结论。     

塑料挤胀成型工艺及成型过程的有限元模拟

介绍了塑料挤胀成型工艺,分析了塑性有限元法对塑料挤胀成型过程的适用性,借助ANSYS有限元分析软件对塑料三通的挤胀成型过程进行了三维有限元模拟,给出了特定条件下的计算结果.     

静力压桩的拉格朗日法模拟与桩周土体固结分析

静力压桩过程是一种稳态贯入过程,常规的有限元方法较难模拟。基于更新的拉格朗日列式法分析压桩时产生的大变形,引入桩-土界面间的接触作用,桩周土体采用MohrCoulomb模型,运用有限元方法进行数值分析,与传统有限元方法相比,更好地实现了静力压桩过程的数值模拟。在此基础上,进一步分析了压桩结束后桩周土体超静孔压消散的固结过程。     

载重子午线轮胎有限元网格自动划分程序研究

基于VisualLISP开发了载重子午线轮胎有限元网格自动划分程序。该程序能够在AutoCAD与Abaqus有限元软件之间建立接口,使用预定数量的割线分割轮胎,可以得到固定数量的节点和单元,适用于结构类似、尺寸略有区别的轮胎有限元网格划分,简化了轮胎有限元网格划分过程。     

含凹坑压力管道受轴向弯矩时的极限载荷分析

采用ANSYS有限元分析软件对含外壁凹坑的压力管道受轴向弯矩时的极限载荷进行了研究,建立了压力管道有限元模型,检验了有限元模型的计算结果。研究结果给出了管道结构塑性区扩展过程,分析了凹坑几何尺寸对管道极限载荷值的影响规律,结果表明,有限元模型计算结果与实测值比较吻合。     

基于Polyflow的制杯机热成型仿真模拟

热成型技术是塑料成型常用技术方法之一。它以成型效率高、投资少等优点得到了广泛的应用。结合CAD软件和有限元CFD软件Gambit建立了有限元模型,利用Polyflow软件模拟了制杯机的热成型过程。以片材厚度作为表征,结合实际热成型产品验证了有限元仿真模拟结果的有效性。结合仿真结果,详述了片材变形及厚度分布的热成型过程,为同类热成型机优化产品结构以及模具设计提供参考和理论依据。     

轮胎离合器充气过程的有限元分析

采用有限元分析软件ANSYS,根据静态充气过程轮胎离合器的受力特点,合理简化几何模型、边界条件和帘布层力学模型,用轴对称平面应变单元建立了轮胎横截面的二维有限元模型,在综合考虑材料非线性、几何非线性和接触非线性的基础上,分析了轮胎充气过程的力学性能。     

共流型转子的有限元分析

通过建立共流型转子的物理模型、数学模型和有限元模型,并运用POLYFLOW有限元分析软件对共流型转子的混炼过程进行了模拟。通过对混炼过程的速度场和粘度场的求解计算,证明共流型转子具有较好的分散和分布混合功能。     

干式气柜结构的有限元分析

主要研究了大型干式气柜的有限元分析方法,详细阐述了该项目的整个计算过程和步骤,包括结构载荷计算、计算工况确定、建模方法、有限元计算和计算结果的评定等。     

酸性水汽提装置增上氨精制系统运行效果

本酸性水汽提装置原来采用单塔加压蒸汽汽提工艺,大检修时改造为单塔汽提侧线抽氨工艺.增加抽氨工艺后的装置运行情况基本良好,具有显著的经济、社会和环境效益.分析了运行中存在的问题并提出了解决问题的建议.     

炼油减压精馏塔汽提工艺传质过程模拟与分析

为了揭示减压塔汽提工艺的传质过程特性,进而改进汽提操作,采用改进的减压精馏过程模拟方法和传质计算方法,分析了炼油常减压装置的汽提工艺的传质特点。在深化对于汽提工艺的理解基础上论证了采用填料汽提塔(段)的必要性以及设计、分析的基本方法。计算分析结果表明侧线汽提塔内填料分离性能保持恒定,汽提塔的分离效率与减压塔对应分离段接近,所以在设计和操作中应给予汽提塔(段)充分重视。减压塔底汽提段的工艺和水力学特点与侧线汽提塔相同。塔底汽提蒸汽质量流率应小于减压塔进料质量流率1%,否则将导致减压塔整体分离效率降低。     

酸性水汽提装置长周期运转的影响因素

根据酸性水汽提装置技术改造及投产建设实践,分析了酸性水汽提装置工艺技术特点,提出保持装置长周期平稳运转应注重汽提工艺的选择、酸性水预处理、汽提塔操作、设备及管道防腐等4个主要影响因素。     

Foam fractionation of solutions containing two surfactants in stripping and reflux columns

An experimental and theoretical investigation was undertaken in order to examine the effect of concentration, foam flow rate and feed flow rate on the separation of sodium dodecylbenzene sulfonate and sodium lauryl sulphate from solutions containing the two surfactants, in stripping and reflux columns. The experimental results indicated the conditions under which a stripping foam fractionation column behaves according to the model of an infinite column. Within the present experimental range reflux columns behaved always according to the model of an infinite column. Using this model it is possible to predict relative separation of surfactants in stripping and reflux columns from experimental data obtained in simple columns. Experiments with modified total reflux columns indicate great potential for batch foam fractionation.     

一氧化碳变换冷凝液汽提工艺技术改进探讨

介绍单塔汽提和双塔汽提两种冷凝液汽提工艺,建议采用单塔汽提侧线抽氨工艺处理含氨量较高的水煤浆变换冷凝液,利用一座汽提塔即可完成变换冷凝液的净化以及将酸性气体与氨分离的任务,侧线抽出的高浓度氨气可以制成氨水或液氨产品。     

Optimal erreichbare Werte der Entbenzinierung in der Endstufe einer Miscella-Destillation

Optimum Values Attainable in Solvent Removal at the Final Stage of Miscella Distillation Starting from the theoretical basis and conventional form of construction of a stripping column for miscella distillation, formulas for stripping steam consumption as function of absolute pressure in column and rest solvent content at a maximum distillation temperature t_max. = 80°C are derived for 4 different modes of distillation. The results are represented graphically in two-dimensional diagrams and compared. Based on the costs of extracting solvent, cooling water and steam, the optimum figures for the consumption of stripping steam are obtained. Also in plant designing with the help of the values given, a yield calculation related to investment costs can be made. For undesirable solvent costs, whereby the stripping steam input is maximum, the diameter of the stripping column and the surface of the condenser involved have to be predetermined.     

Effect of internal distributors in a packed column on the steam stripping of hexane from soybean oil

Internal distributors were designed and installed in a 6-in. diameter column with an 8-ft bed of 1/2-in. berl saddles. The distribution pattern of a liquid (water) flowing down the column was first determined. The distributors picked up the water from the wall of the column and redistributed it towards the center producing definitely better distribution across the column than obtained without them. Steam stripping of hexane from soybean oil was next carried out in the column both with and without the distributors. The residual hexane in the oil varied exponentially with the steam-oil ratio. Under the experimental conditions 18% less steam was required for comparable stripping with the distributors in the column than without them.     

钛材汽提塔使用过程中出现的问题及对策

根据汽提塔使用过程中所发生的问题及采取的处理方法进行分析探讨,找出影响设备正常运行的不利因素,采取相应的有效措施,延长汽提塔的使用寿命.     

连续重整进料硫含量超高事故分析

简述了连续重整装置重整反应部分硫中毒的现象,通过分析得出罐区来的精制石脑油所带溶解氧与预加氢反应产生的硫化氢在汽提塔内生成单质硫,是引起硫含量偏高的原因。切断罐区来精制石脑油进汽提塔后,重整进料硫含量恢复正常。     

IN SITU SEPARATION OF ETHANOL DURING BATCH FERMENTATION WITH CO_2 STRIPPING AND ACTIVATED CARBON ADSORPTION

In situ separation of ethanol during batch fermentation with CO_2 stripping and activated carbon adsorption was studied. The higher initial glucose concentration and fermentation rate were reached due to the elimination of ethanol inhibition on the cell growth by means of CO_2 stripping. The stripped ethanol vapor was selectively adsorbed by an activated carbon column. The conde(?)sate desorbed from the adsorption column can be higher than 50% by weight. Ar unstructured model was used to simulate the experimental data satisfactorily.