6m焦炉四大车供电系统的改进

重钢新区焦炉投产以来,四大车供电系统多次出现故障,经改造可实现分段停电检修;1套集电器可连续稳定使用半年以上,且更换1套集电器仅用20min左右;各滑触线增加自动伸缩器后,只要对滑触线定期检查松动,保证其自由伸展,滑触线基本不变形,焦炉运行能力大大提高.     

Experimental Research on Parallel Conversion Control of Drying Temperature in a Closed-Loop Heat Pump Dryer

The paper proposes a method to handle the challenge of temperature control in a closed-loop heat pump dryer that can operate both in heating cycle and refrigeration cycle. It is hard to avoid the violent fluctuations of drying temperature as the operation mode changes. Hence, the parallel conversion control is introduced to realize the accurate control of drying temperature. The main idea of the controller design lies in the use of different membership functions and fuzzy control rules for the two operation modes. Experimental results show that the temperature fluctuations are reduced when using parallel conversion control with fast and stable response as compared to the fixed-frequency and PID control system. One of the parameters, R _f , representing the value of undershoot ratio is 0.4, 0.48, and 0.64 when drying temperature is fixed at 30, 35, and 38°C, respectively, with a parallel conversion controller. In order to study the application prospects of the parallel conversion control system, a comparison experiment with different compressor frequency ranges was also conducted.     

MPI环境下二维流动的并行计算

在MPI并行环境下,使用Fortran语言自行开发的程序,采用区域分解法对二维流动问题进行了数值模拟计算。最后分析了计算机集群在数值求解复杂流动问题方面的实用性以及实际所能达到的计算效率。     

Analysis of dialysis coupled with ultrafiltration through cocurrently parallel-flow rectangular membrane modules

The mass transfer for the systems of dialysis with ultrafiltration in cocurrently parallel-flow rectangular membrane modules was investigated, based on mass balances with the assumption of uniform ultrafiltration flux. Considerable improvement in separation efficiency is achievable if the effect of ultrafiltration is applied, especially for the system with low mass transfer coefficient. The enhancement in separation efficiency is significantly increased with increasing ultrafiltration flux, as well as with increasing the volumetric flow rates. Furthermore, increasing the volumetric flow rate in retentate phase is more beneficial to mass transfer than increasing in dialysate phase.     

进入WTO前夕的中国塑料机械行业

介绍了中国塑料工业概况和中国塑料机械行业现状,并在比较了国内塑机行业与国外差距的基础上,提出了赶超国际先进水平的建议。     

电机槽漏抗的有限元分析

定子绕组槽漏抗是电机的一个重要电磁参数。在一些大型电机设计中,准确计算电机的槽漏抗是必要的。实测表明,传统的设计公式得到的槽漏抗值偏小。本文通过磁场分析来计算电机的槽漏抗,能计及电机磁路及导体的实际布置,求出两维磁场分布,进而得到合理的漏抗值。 Sereen-Mesh软件被应用于磁场分析中,运用有限元网格自适应技术,使新的槽漏抗计算方法在精度和经济性上都能满足工程实用的需要。     

凸极同步电机小信号运算电感的计算

小信号运算电感数值计算中的问题有:增量磁导率的使用,转子绕组的处理等。本文采用场路耦合法处理转子的阻尼绕组和励磁绕组,既合理地反映了转子的复杂回路,又避免了端部漏磁引起的修正。通过对采用不同磁导率计算的比较,得到了一些具有实际意义的结果。     

基于FCMISVM的自适应软测量建模算法及其在PX吸附分离过程中的应用

To overcome the problem that soft sensor models cannot be updated with the process changes, a soft sensor modeling algorithm based on hybrid fuzzy c-means (FCM) algorithm and incremental support vector machines (ISVM) is proposed. This hybrid algorithm FCMISVM includes three parts: samples clustering based on FCM algorithm, learning algorithm based on ISVM, and heuristic sample displacement method. In the training process, the training samples are first clustered by the FCM algorithm, and then by training each clustering with the SVM algorithm, a sub-model is built to each clustering. In the predicting process, when an incremental sample that represents new operation information is introduced in the model, the fuzzy membership function of the sample to each clustering is first computed by the FCM algorithm. Then, a corresponding SVM sub-model of the clustering with the largest fuzzy membership function is used to predict and perform incremental learning so the model can be updated on-line. An old sample chosen by heuristic sample displacement method is then discarded from the sub-model to control the size of the working set. The proposed method is applied to predict the p-xylene (PX) purity in the adsorption separation process. Simulation results indicate that the proposed method actually increases the model’s adaptive abilities to various operation conditions and improves its generalization capability.     

微操作并联机器人几何误差建模的参数误差转换法及误差敏感性分析

提出微操作并联机器人几何误差建模的参数误差转化法,建立正交结构6-PSS微操作并联机器人的几何误差模型,通过构造几何误差模型的Lagrange条件极值方程,对误差进行敏感性分析,最后讨论了各类参数误差在终端几何误差模型中的关联性。研究表明：所提出的方法简单明了,行之有效。     

Parallel Kinematic Machine Tools - Current State and Future Potentials

Parallel kinematics have recently attracted attention as machine tools because of their conceptual potentials in high motion dynamics and accuracy combined with high structural rigidity due to their closed kinematic loops. This paper, prepared with input from CIRP colleagues as well as of machine manufacturers and end-users involved in PKM, attempts to review the development of parallel kinematics for machine tools, their practical application and their performance compared to classical machine tools.