A decomposing technique for scheelite concentrate and low-grade scheelite concentrate

The effect of different decomposition conditions on tungsten recovery for scheelite concentrate has been examined. The results show that tungsten recovery can be more than 98% under decomposing conditions as follows: the amount of caustic soda is 2.2 and 3.2 times of theoretical respectively, ratio of water and ore is 0.7-0.8, temperature is 160℃, and preservation time is 2.0 h for scheelite concentrate (63.21% WO3) and low grade scheelite concentrate (55.17% WO3).     

液压轧机压下油缸内置式检测装置

介绍了压下油缸内置式检测装置的结构、技术原理、主要特点及其在AGC液压压下系统控制中的使用情况。结果表明:该装置性能良好,使用可靠,线性度为0.02%,分辨率为0.002 mm,响应速度为10 m/s。     

采用12Cr1MoV转炉钢生产高压锅炉钢管

介绍了转炉冶炼高压锅炉管钢工艺和采用12Cr1MoV 转炉钢生产的高压锅炉钢管性能。性能试验表明,转炉钢可以用于高压锅炉钢管生产,其实物质量与电炉钢相当。     

铝及铝合金型材等温挤压关键技术研究进展

介绍了等温挤压工艺的原理及优点,分析了铝型材挤压过程中的热量变化,指出了挤压制品出口温度的影响因素,并以此为基础介绍了实现铝型材等温挤压工艺的几种方法,包括先进的铝型材挤压技术——温度和速度闭环控制的等温挤压原理及实现方法。     

论现代双线干油集中润滑系统的高压化趋势

本文论述了双线干油(脂)集中润滑系统的发展简史和现代高压双线干油集中润滑系统,并对低压(138bar)、中压(210bar)和高压(400bar)系统的管路内润滑脂滞留时间及它们的综合投资费用和经济性等进行了分析比较,阐明了其高压化趋势的原因。     

70m/min PC钢棒生产线

介绍了生产率达70m／min的PC钢棒生产线的构成及其运行原理，以φ9mm的钢棒为例，给出系统运行的电气参数，并分析对比了该生产线热处理与其他同类生产线的吨电耗。经该线处理的PC钢棒产品的力学性能达到国标。结果表明本系统是高效率的，高质量的，高稳定性的PC钢棒生产线。     

Maximizing biogas production from the anaerobic digestion

This paper presents an optimal control law policy for maximizing biogas production of anaerobic digesters. In particular, using a simple model of the anaerobic digestion process, we derive a control law to maximize the biogas production over a period T using the dilution rate as the control variable. Depending on initial conditions and constraints on the actuator (the dilution rate D(·)), the search for a solution to the optimal control problem reveals very different levels of difficulty. In the present paper, we consider that there are no severe constraints on the actuator. In particular, the interval in which the input flow rate lives includes the value which allows the biogas to be maximized at equilibrium. For this case, we solve the optimal control problem using classical tools of differential equations analysis. Numerical simulations illustrate the robustness of the control law with respect to several parameters, notably with respect to initial conditions. We use these results to show that the heuristic control law proposed by Steyer et al., 1999 [20] is optimal in a certain sense. The optimal trajectories are then compared with those given by a purely numerical optimal control solver (i.e. the “BOCOP” toolkit) which is an open-source toolbox for solving optimal control problems. When the exact analytical solution to the optimal control problem cannot be found, we suggest that such numerical tool can be used to intuiter optimal solutions.     

主动叶尖间隙模型预测控制系统设计与仿真

为将发动机全工况内叶尖间隙控制在最佳状态,首先,提出实现间隙主动控制的双闭环控制系统结构;其次,设计一种由多个电子机械式作动装置成的可变结构的机匣结构,并建立了其数学模型;然后,应用基于串级模型预测控制的主动间隙控制策略,完成了控制器的设计;最后,以某发动机叶尖间隙变化为被控对象,仿真验证了所设计系统.结果表明:所设计系统控制偏差≤0.01 mm,对对称性间隙变化和非对称性间隙变化的控制效果均较好,可为主动叶尖间隙控制的实现提供参考.     

A Measurement‐Based Approach for Designing Fixed‐Order Controllers for Unknown Closed‐Loop Architecture

This paper presents a new technique to design fixed‐structure controllers for linear unknown systems using a set of measurements. In model‐based approaches, the measured data are used to identify a model of the plant for which a suitable controller can be designed. Due to the fact that real processes cannot be described perfectly by mathematical models, designing controllers using such models to guarantee some desired closed‐loop performance is a challenging task. Hence, a possible alternative to model‐based methods is to directly utilize the measured data in the design process. We propose an approach to designing structured controllers using a set of closed‐loop frequency‐domain data. The principle of such an approach is based on computing the parameters of a fixed‐order controller for which the closed‐loop frequency response fits a desired frequency response that describes some desired performance indices. This problem is formulated as an error minimization problem, which can be solved to find suitable values of the controller parameters. The main feature of the proposed control methodology is that it can be applied to stable and unstable plants. Additionally, the design process depends on a pre‐selected controller structure, which allows for the selection of low‐order controllers. An application of the proposed method to a DC servomotor system is presented to experimentally validate and demonstrate its efficacy.     

污水处理厂污泥厌氧消化优化设计与运行探讨

对国内典型的污水处理厂污泥厌氧消化系统进行调研发现,厌氧消化系统的运行管理尚存在诸多问题。在总结白龙港污水处理厂污泥厌氧消化调试与运行管理经验的基础上,针对厌氧消化工艺存在的普遍性问题,提出了厌氧消化系统设计和运行管理方面的建议,以促进工艺设计优化,提高运行管理水平。