TDI双管板换热器制造质量的控制简

介绍了TDI双管板换热器的结构特点和深孔强度胀接技术。简述了制造过程中的质量控制关键点。通过用模拟管板进行了内管板胀接工艺评定的方法,采取了控制管孔加工精度、强度胀接、管板组装、调整开槽间距及宽度、安排合理的胀接焊接次序、选择合适的胀接压力等措施;采用了新的检验和检测技术,保证了产品质量;增设了压力传感器,完善了安全监测系统。     

Tandem Strip Mill’s Multi-parameter Coupling Dynamic Modeling Based on the Thickness Control

The rolling process is determined by the interaction of a number of different movements,during which the relative movement occurs between the vibrating roll system and the rolled piece,and the roll system’s vibration interacts with the strip’s deformation and rigid movement.So many parameters being involved leads to a complex mechanism of this coupling effect.Through testing and analyzing the vibration signals of the mill in the rolling process,the rolling mill’s coupled model is established with comprehensive consideration of the coupling interaction between the mill’s vertical vibration,its torsional vibration and the working roll’s horizontal vibration,and vibration characteristics of different forms of rolling mill’s vibration are analyzed under the coupling effect.With comprehensive attention to the relationship between the roll system,the moving strip and the rolling parameters’dynamic properties,and also from the strip thickness control point of view,further research is done on the coupling mechanism between the roll system’s movement and the moving strip’s characteristics in the rolling process.As a result,the law of inertial coupling and the stiffness coupling effect caused by different forms of the roll system’s vibration is determined and the existence of nonlinear characteristics caused by the elastic deformation of moving strip is also found.Furthermore,a multi-parameter coupling-dynamic model is established which takes the tandem strip mill as its research object by making a detailed kinematics analysis of the roll system and using the principle of virtual work.The coupling-dynamic model proposes the instruction to describe the roll system’s movement,and analyzes its dynamic response and working stability,and provides a theoretical basis for the realization of the strip thickness’dynamic control.     

Effect of tempering temperature on microstructure and mechanical properties of high boron white cast iron

The effect of different tempering temperatures on the microstructure and mechanical properties of airquenched high boron white cast iron was studied.The results indicate that the high boron white cast iron comprises dendritic matrix and inter-dendritic M 2 B boride;and the matrix comprises martensite and pearlite.After quenching in the air,the matrix is changed into lath martensite;but only 1-μm-size second phase exists in the matrix.After tempering,another second phase of several tens of nanometers is found in the matrix,and the size and quantity increase with an increase in tempering temperature.The two kinds of second precipitation phase with different sizes in the matrix have the same chemical formula,but their forming stages are different.The precipitation phase with larger size forms during the austenitizing process,while the precipitation phase with smaller size forms during the tempering process.When tempered at different temperatures after quenching,the hardness decreases with an increase in the tempering temperature,but it increases a little at 450 ℃ due to the precipitation strengthening effect of the second phase,and it decreases greatly due to the martensite decomposition above 450 ℃.The impact toughness increases a little when tempered below 300 ℃,but it then decreases continuously owing to the increase in size and quantity of the secondary precipitate above 300 ℃.Considered comprehensively,the optimum tempering temperature is suggested at 300 ℃ to obtain a good combination of hardness and toughness.     

矿井提升机减速器润滑磨损故障监测及诊断技术研究

为提高工作可靠性,构建本质安全生产环境,促进实现安全高效,研究了矿井提升机减速器润滑磨损故障监测及诊断技术,考察了监测采样的技术理论基础;采用油液分析与铁谱技术方法,分析了圆柱直齿轮、人字圆弧齿轮、滚动轴承及滑动轴承的摩擦学特性;建立了合理选油、适时换油、适时维护及预知检修等试验分析与判断决策模型,并举例说明如何应用。     

试论节能球磨机专用滚动轴承的受力状态

初步分析了节能球磨机专用滚动轴承的受力状态,阐述了专用滚动轴承几个参数的修正系数,对该类轴承的校核提出了建议,并对部分应用实例进行了归纳总结。     

基于虚拟样机的铲运机整机动力学仿真研究

针对地下铲运机整机动力学仿真分析的不足,提出虚拟样机意义下整机动力学全工况仿真分析的方法。根据实际作业工况,建立了前车体与举升臂有无接触、正载或偏载的4个动力学仿真模型,并分别对每个模型在工作过程中的8个典型子工况进行整机动力学仿真。首次求解出举升臂与前车体的接触力,确定了关键零部件强度分析的危险工况为偏载工况下的掘起工况和重载运输工况,得到了用于关键零部件强度和疲劳分析的各铰点的全工况受力情况。     

重整装置预加氢进料换热器管束失效分析

通过现场勘察和检验检测分析,认为某石化公司重整装置预加氢进料换热器管束的腐蚀外表面较内表面严重得多。管束外表面的腐蚀主要是H₂S等腐蚀性介质引起的较严重的均匀腐蚀,且局部结垢形成垢下腐蚀,因活性阴离子的存在而导致局部发生腐蚀穿孔。在分析失效原因的基础上,从设计、工艺和材料等方面提出了防腐蚀措施。     

MLK立磨生产矿粉和矿渣水泥的操作经验

立磨对于不同物料具有较高的适应性并且换料调节方便、迅速,不少企业采用了单台立磨分时段生产矿粉及矿渣水泥的生产方式.天津某水泥公司利用国产MLK2650立式矿渣磨分时段生产矿粉及矿渣水泥,产品质量高,成分稳定,节能效果显著.     

废油再生装置冷却设备涡旋压缩机结构参数优化

涡旋压缩机结构参数直接影响到润滑油分子蒸馏再生装备的效率。以基于泛函通用涡旋型线构成的变壁厚涡旋盘为研究对象,建立了以能效比为目标函数的结构参数优化模型。分析了涡旋压缩机压缩过程中由排气容积变化引起的热能变化及能效比变化。以能效比为目标函数,以涡旋盘结构参数及型线方程为变量,利用遗传算法得到能效比最优化时的变量。给出具体算例,并与等壁厚的涡旋型线构成的压缩机进行性能比较,得知前者更优。基于泛函的通用涡旋型线为涡旋压缩机型线设计拓展了思路。     

基于容错度自适应支持向量机的液压泵故障诊断

针对已有在线故障诊断方法在数据量大、噪声强条件下分类速度较低、分类精度不够高等问题,结合液压泵故障类别数目大、工作环境恶劣的特点,提出了一种适用于混凝土泵车液压泵在线诊断的状态识别算法——容错度自适应支持向量机。该方法主要从四个方面对分类速度做了改进：①引入容错度因子进行模型训练;②优先选择能将某一类故障样本单独分离出来的二分类器;③在满足②的基础上选择平均支持向量机少的分类器;④引入增量学习算法对参数进行自适应调整,提高多故障诊断中对新故障类别和新故障数据的适应性,保证系统的分类精度。通过对混凝土泵车的液压泵故障诊断,证明了该方法在明显提高分类速度的同时保证了较高的分类精度。