重型矿用汽车的动力学建模与仿真

重型矿用汽车工作条件比较恶劣,长期在满载、振动与冲击载荷下工作,因此,提高重型车辆的平顺性十分必要。仿真分析采用虚拟样机技术,其具有丰富的建模功能和强大的运动学、动力学解算能力,可以建立规模庞大、机构复杂,系统级的仿真模型,进行汽车整车性能仿真分析。本文利用美国MDI公司的动力学仿真分析软件ADAMS,建立SGA3550重型矿用自卸汽车整车动力学仿真模型,并进行平顺性仿真。     

Conversion of biodiesel synthesis waste to hydrogen in membrane reactor: Theoretical study of glycerol steam reforming

Hydrogen production from waste glycerol, mainly producible as a by-product of biodiesel synthesis, is investigated as an attractive opportunity for exploiting renewable energy sources for further applications. Glycerol steam reforming using membrane technology was modeled by taking into accounts the maim transport phenomena, thermodynamic criteria and chemical process kinetics. A sensitivity analysis of operating conditions was made for key performance metrics such as glycerol conversion, hydrogen yield and hydrogen recovery. Glycerol conversion intensifies with enhancement of operating pressure and temperature, whereas high feed molar ratio and sweep ratio have limiting effect. Hydrogen permeation and subsequently, hydrogen recovery facilitates with increasing sweep gas ratio and sweep gas temperature. Hydrogen recovery enhances from 70% to 99% with increasing temperature from 350 to 500 °C at feed molar ratio of 3. Also, hydrogen recovery improves from 50% to 71% with increasing sweep ratio from 0 to 20 at 350 °C and 1 bar.     

漂白过程温度建模与控制

文章介绍了阶跃响应建模法的思想并利用该方法建立了漂白过程温度的数学模型。针对温度控制的大时滞性,采用改进的继电反馈辨识法来自整定PID控制器的参数,获得了良好的实时控制效果。     

基于电感法的微型BLDCM控制系统建模与仿真

对于微型BLDCM在负载较大和低速运行的场合,采用传统无位置传感器控制技术出现启动反转和启动困难的情况,首先根据安培环路定理分析相电感与转子位置的关系。通过施加一定顺序的电压矢量,设计了一套根据其电流响应来判断转子位置的方法;然后使用Matlab/Simulink搭建控制系统模型,并进行仿真。实验结果表明:采用此方法,微型BLDCM可以在较大负载的情况下从任意位置无反转启动,并且可以低速运行。     

基于有限元分析的减速机箱体造型设计

为解决减速机箱体相似度大、厂家品牌识别度低的问题,提出将把箱体技术要求、企业文化内涵和中国传统文化等融合在减速机箱体外观的设计理念中。将有限元分析方法引入传统的减速机箱体造型设计流程,运用Creo2.0软件进行三维设计并建模;用Ansys Workbench软件对设计模型进行有限元分析;提出了造型与结构一体化的设计方法,通过此方法达到提高各减速机厂家品牌识别度的目的,从而提高产品的竞争力,增强产品造型的创新性,提高造型设计效率。     

液压起重机柔性平动连杆建模新方法及误差仿真研究

针对液压起重机运动过程中,压力和选择角度变化难以预测问题,对液压起重机进行建模,提出了基于假设模态液压起重机运动控制模型。介绍了液压起重机结构,采用拉格朗日定理对液压起重机运动臂进行建模,推导出起重机动力学方程式。同时,假设平动连杆近似为单梁,对液压起重机伸缩臂的变形进行研究,采用MATLAB软件对液压起重机执行机构的压力和吊杆的旋转角度进行仿真,并且与实际测量值进行比较。结果表明:液压起重机执行机构的仿真压力变化值、吊杆的旋转角度变化值与实际测量值接近,能够对实际工作中压力变化及吊杆的旋转角度变化值进行很好的预测。采用假设模态建立的液压起重机运动模型,能够有效的模拟起重机臂运动产生的压力变化和角位移变化。     

Kinetic study on reactive extraction of phenylalanine enantiomers with BINAP-copper complexes

Enantioselective liquid–liquid extraction has attracted considerable attention for its potential use in large-scale production. Kinetic data are needed for the reliable scale-up of the process. This paper reports the kinetic study of reactive extraction of phenylalanine (Phe) enantiomers with BINAP–copper complex (BINAP–Cu) as a chiral selector. The theory of extraction accompanied by a chemical reaction was applied. The effects of agitation speed, interfacial area, pH value of aqueous phase, initial concentration of Phe enan-tiomers and initial concentration of BINAP–Cu on the specific rate of extraction were investigated. The for-ward rate constants of the reactions in the reactive extraction process are 7.93 × 10?5 m5/2·mol?1/2·s?1 for D-Phe and 1.29 × 10?4 m5/2·mol?1/2·s?1 for L-Phe.