内外循环超重力装置对润滑油清净剂产品的影响

随着超重力技术的应用领域的不断开拓,用超重力装置可制备高碱值石油磺酸钙清净剂T103,在用内外循环超重力装置制备T103过程中,讨论了内外循环超重力装置对润滑油清净剂产品的影响.结果表明,内循环超重力装置比外循环超重力装置结构简单,采用内循环超重力装置比外循环超重力装置在制备T103过程中原料的利用率高、产品收率高、装...     

影响高压溶出温度的因素分析

溶出温度是高压溶出生产中一个非常重要的控制参数及生产条件,是影响溶出过程最主要的因素.提高溶出温度可以大大缩短溶出时间和提高设备产能,使氧化铝溶出率显著上升.本文对实际生产中影响溶出温度的因素进行分析,并提出一些改善措施.     

膛内运动弹丸微多普勒建模与仿真

针对太赫兹波段弹丸膛内轴向运动同时存在横向摆动产生的微多普勒现象不容忽略的情况,文中采用刚体运动学和传统多普勒分析相结合的方法,推导了其微多普勒数学公式和回波信号模型.通过仿真验证了理论推导的正确性,同时表明弹丸平动加速度会使微多普勒沿时变频率方向发生倾斜,其附加频率调制作用使提取的弹丸速度产生波动,为进一步研究微多普勒提取技术提供了理论基础.     

The use of flexible interface theory for fully coupled nonlinear analysis of balanced adhesive single-lap joint

A theoretical model is presented for determining the edge moment factors, the transverse deflections and the interfacial stresses of the balanced adhesive single-lap joint (SLJ). Based on the flexible interface theory, the improved one-dimensional beam model incorporates simultaneously the effects of interfacial compliances, the overlap geometric nonlinearity and the transverse shear deformations for the adherends. On the basis of normal and tangential displacement compatibility condition for the flexible interface, two sets of fully coupled governing equations concerning rotation of transverse normal and longitudinal displacement of adherends are constructed, from which the improved solutions for the edge moment factors, the transverse deflections, and the interfacial stresses can be obtained. The applicability and accuracy of the improved one-dimensional beam model are validated by comparing the present solutions with the results of the classical model, non-linear finite element analysis, and experimental results. Finally, the effects of the interface compliances on the adhesive stresses distributions of the balanced SLJ are studied.     

A CORRELLATION FOR CYLINDER-TO-BED HEAT TRANSFER IN AERATED VIBRATED BEDS OF SMALL PARTICLES

ABSTRACT

Beds of alumina particles (d_p= 27 μm and 100 μm) were vibrated in the vertical direction at frequencies frdm 0–25 Hz and half-amplitudes from 0–4 mm. Air flow rate through a single-hole or multiple-holes bottom plate varied from 0 to 2 times the minimum fluidizing velocity. The contact heat transfer coefficients at resonance are much higher than those in packed beds and in vibrated fluidized beds (up to 1.2 times). The high heat transfer rates are due to enhanced particle mobility which reaches a maximum at the resonant point. A simple semi-empirical correlation is developed for contact heat transfer which is based on particle mobility. Heat transfer coefficients are correlated with frequency using amplitude, bed height and particle size as adjustable parameters. The correlation is found explain the observed trends in the data reasonably well over the range of parameters studied.     

新型外永磁转子横向磁通爪极电机特性仿真

为了研究具有特殊结构的新型外永磁转子横向磁通爪极电机的运行特性,在对该种电机的结构特点以及运行机理进行分析的基础上,利用有限元分析软件,建立了该种电机的三维电磁场分析仿真模型,仿真得到了该种的电机的气隙磁密波形和电机整体的磁密分布;然后分析了该种电机的空载感应电动势及齿槽转矩的波形;最后用自行开发了外永磁转子横向磁通爪极电机的磁路仿真程序,并对该种电机进行了性能仿真研究,结果表明该种新型结构的横向磁通爪极电机具有良好的运行特性,为该种电机的深入研究打下了技术基础.     

一起水轮发电机横差保护动作原因分析及故障处理

针对一起水轮发电机横差保护动作故障进行分析,找出故障原因,提出改进措施。分析结果表明：由于7号、8号磁极间连片烧断,导致绕组发生匝间短路,引起横差保护动作;更换7号、8号磁极后,机组运行正常,再未发生横差保护动作现象。     

基于预定涡尾迹法的风力机性能研究

以三叶片水平轴风力机为研究对象,建立了尾迹扩张模型,研究了叶片尾迹流动结构。涡面模型叶片无量纲环量的计算结果与经典环量数据对比,结果吻合较好。计算了根尖涡模型风轮面诱导速度随尾迹扩张系数的变化关系,得出了尖速比对气动性能的影响:推力系数与环量及尖速比成正比;对于不同环量,功率系数存在最佳尖速比。分析了尾迹扩张模型对气动性能的影响:推力系数和功率系数与尾迹扩张系数成正比,尾迹收敛参数对其影响甚微。     

差速流化床密相区内流动特性的数值模拟

基于颗粒动力学理论,采用Fluent软件中标准k-ε方程模型和欧拉-欧拉双流体模型对差速流化床底部密相区内的气固两相流动过程进行了数值模拟,分析了内循环过程中颗粒速度和压力等流动特性参数的分布和变化规律,研究了主、副床风速对密相区流场的影响.结果表明:保持副床风速u2=1.5m/s不变,随着主床风速的增大,主床的时均颗粒体积分数降低,副床的时均颗粒体积分数升高,压力降方差和回流速度增大;保持主床风速u1=4.0m/s不变,随着副床风速的增大,回流速度减小,压力降方差先增大后减小,当副床风速为2.0m/s时气固两相流动最强烈.     

郑庄-胡底煤层气地球化学特征及成因探讨

结合沁水盆地南部地质构造史和热演化过程,从甲烷碳同位素与煤岩镜质组反射率、甲烷碳与氢同位素、甲烷与水的氢同位素值定量关系3方面探讨了郑庄和胡底区块煤层气成因,结果表明:煤层气组分中,甲烷体积分数占绝对优势,为96.83%~98.55%,为极干燥气体;甲烷δ13C1和δD分别为-33.1‰~-30.8‰和-179.32‰~-160.53‰;煤层气主要为经次生改造的热解成因煤层气。煤层气δ13C1实测值与推测值-27.89‰相比明显偏轻,其原因是燕山期异常古地温阶段,横向地下水循环和竖向热液循环过程中流体优先溶解13CH4产生的甲烷碳同位素分馏作用的结果。15号煤抽采煤层气甲烷氢同位素值与伴生水氢同位素值定量关系表明,由于CO2还原次生生物作用造成3号煤和15号煤抽采煤层气甲烷δD的差异。