山西某大型工业厂房的结构设计

结合工程实例,对大型工业厂房设计中应注意的问题进行分析研究。针对下层吊车起重吨位较小的特点,采用格构柱悬臂牛腿的做法,有效地减小钢柱在厂房内部的占地面积;针对超宽厂房的横向温度变形进行分析,采用单下柱、双上柱的格构柱形式,经与传统的双列柱的形式对比,可有效提高厂房内部使用空间,并降低用钢量;针对厂房纵向超长的特点进行温度应力计算,通过适当增强柱间支撑,合理布置屋面水平支撑等技术措施形成空间整体刚度体系,既满足厂房变形要求,确保了结构安全,又能节约一榀刚排架及基础。     

富马酰基桥联双冠醚的晶体结构及其对金属离子的选择键合

通过母体冠醚环(苯并氮杂-15-冠-5)与富马酰氯反应,合成了一种新型的富马酰基桥连的双冠醚,其单晶结构经X-射线单晶衍射仪测定;继而采用溶剂萃取法考察了其对金属离子(Li~+、Na~+、K~+、Rb~+、Cs~+、Ag~+、Tl~+)的识别能力。结果显示,该双冠醚对Li~+具有较高的萃取率和选择性。     

双闭环模糊PI控制的双馈式风机并网研究

将模糊控制与PI控制相结合,应用于双馈式风机网侧变换器控制中。采用外环电压模糊PI控制、内环电流控制的双闭环控制系统来克服运行时发电机参数发生变化带来的干扰。在Matlab/Simulink中搭建仿真模型进行仿真,结果表明:该方法在运行过程中可以很好地克服风速和电机参数变化的影响,定子端电压的波形、幅值、频率均达到并网要求,谐波含量少。     

Design of parallel cyclones based on stability analysis

The uniform distribution of gas solids flow across parallel cyclones is required for high efficiency. In this study, we introduced mass flow rate ratio between solids and gas (C_T) to present multi‐phase interaction. And the direct Liapunov method is used to detect the instability of uniformity. Due to the special symmetry in this system, the criterion can be simplified into identifying the concavity (concave or convex) of pressure drop across a single cyclone with respect to C_T. Then, based on the stability analysis of uniformity, a novel design principle is provided to prevent non‐uniform distribution at dense phase. The effect of geometrical factor, i.e. dimensionless vortex finder diameter d_r, on the stability of uniformity has been further investigated. The phase diagram, illustrating the effects of both operational parameter (C_T) and geometrical parameter (d_r) on stability of uniformity is calculated to give a clue of designing a robust parallel cyclones system. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4251–4258, 2016     

Uncertainty quantification via bayesian inference using sequential monte carlo methods for CO2 adsorption process

This work presents the uncertainty quantification, which includes parametric inference along with uncertainty propagation, for CO₂ adsorption in a hollow fiber sorbent, a complex dynamic chemical process. Parametric inference via Bayesian approach is performed using Sequential Monte Carlo, a completely parallel algorithm, and the predictions are obtained by propagating the posterior distribution through the model. The presence of residual variability in the observed data and model inadequacy often present a significant challenge in performing the parametric inference. In this work, residual variability in the observed data is handled by three different approaches: (a) by performing inference with isolated data sets, (b) by increasing the uncertainty in model parameters, and finally, (c) by using a model discrepancy term to account for the uncertainty. The pros and cons of each of the three approaches are illustrated along with the predicted distributions of CO₂ breakthrough capacity for a scaled‐up process. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3352–3368, 2016     

球磨双闭路工艺生产超细钢渣微粉的实践

2014年JTC公司投产建成一条处理80万t/a钢渣微粉生产线,原料为当地炼钢厂外排的一种转炉钢渣。为节省投资,经多方论证,该公司利用原有的两台球磨机组成了分段粉磨、过程分选和精粉回路除铁的双闭路粉磨工艺。该项目已取得成功实践,为钢渣的资源化利用找到了一条切实可行的方法。     

碳含量对430铁素体不锈钢耐晶间腐蚀性能的影响

利用双环动电位再活化法(DL-EPR)、扫描电子显微镜(SEM)和能谱仪(EDS)研究了碳含量对430铁素体不锈钢耐晶间腐蚀性能的影响。结果表明:单纯的再活化率不能评价430铁素体不锈钢的晶间腐蚀敏感性,需要结合DL-EPR试验后材料表面形貌的电镜观察结果进行综合判断;对430铁素体不锈钢来说,碳含量越高,敏化时间越长,其晶间腐蚀倾向越大。     

双丝单电源单弧工艺在大焊角尺寸平角焊中的应用

介绍了在变压器油箱加强筋的焊接过程中,双丝单电源埋弧焊设备的选择和不同焊接参数下的施焊情况,包括双丝单电源埋弧焊机的结构配置内容以及设备的主要技术参数。从焊缝的外观、成形、咬边情况以及脱渣效果等不同方面对焊接参数进行优选。通过对比埋弧焊、气体保护焊在同等焊接强度时的焊接时间、焊角高度以及焊缝外观质量,体现出双丝单电源埋弧焊在焊接效率、焊接质量、焊缝外观以及焊材节约等方面的优势。同时也阐述了双丝单电源埋弧焊在使用方面的局限与不足。通过大量的焊接试验,确定了适合大型变压器油箱加强筋的埋弧自动焊工艺,提高了工作效率。     

双热丝MAG焊接设备及工艺

双热丝MAG焊接技术(Double Hot Wires MAG Welding Technology)是一种高效焊接方法。在焊接过程中有一根主焊丝和两根热丝。主焊丝和母材之间产生主弧,热丝加热电源的两个输出端子分别与两根焊丝连接,经焊接熔池构成闭合回路。该工艺采用电阻热预热焊丝,利用熔池的能量最终熔化焊丝,在增大熔敷效率的同时,有效降低焊接热输入。研究热丝电流I_(res)对焊丝熔敷速率的影响规律,并进行厚板的多层摆动焊接。结果表明,随着I_(res)的增大,焊丝熔化速度增大,并且每一个热丝电流对应一个最佳热丝送丝速度范围,最大熔敷速度可达25 kg/h以上,有效提高了焊接效率。     

2-PRR并联机构的静刚度试验研究

在不考虑驱动电机刚度的条件下,分别在2-PRR并联机构的连杆平面内的3个典型位置沿X和Z向分步加载,测量得到了在相应方向上的位移值,给出不同位置和方向上的刚度曲线,并将所测的位移值与边界元法计算的位移解析值进行了比较。结果表明:在同一个测量点,Z向刚度明显比X向刚度大,在不同的测量点,其特定方向的刚度虽有变化,但刚度变化在同一数量级;实际测试的相对刚度值与边界元计算的理论刚度值的变化趋势一致。