二乙烯基苯改性煤沥青的流变行为

研究了二乙烯基苯(DVB)改性煤沥青的流变行为.采用SEM和EDAX对改性前后沥青的形貌和组成进行分析,采用旋转黏度计测试改性沥青的流变性能.研究表明:改性沥青中出现分布均匀的微纤;随着改性沥青中甲苯可溶物含量的减少,其黏性流动活化能变大;改性沥青的剪切速率越高,改性沥青的表现黏度越小.     

采用加压-真空两段热缩聚法制备中间相沥青炭纤维的原料

以深度裂解石油渣油为原料，采用两段热缩聚法可制得软化点为268℃，可编性良好的中间相沥青。本文详细考察了温度，时间对中间相沥青软化点，可编性，中间相沥青形态及碳化收率的影响，并初步探讨了两段热缩聚反应的机理。研究结果表明反应温度，时间对中间相沥青的结构和性能影响较大，选择适宜石油渣油，采用加压－真空两段热缩聚法，调整反应条件，可制得可纺性良好的中间相沥青。     

共炭化对热缩聚及炭化工艺过程的影响

采用煤沥青闪蒸油为原料,乙烯残油为添加剂,在实验室内进行热缩聚及炭化实验。结果表明:加入添加剂后,缩聚沥青的平均分子结构得到改善,从而显著改善了针状焦的显微组织结构,同时具有良好的脱氮效果。     

两种沥青炭微观结构和性能的对比研究

将高温煤沥青和浸溃荆沥青在92MPa下炭化，在2500℃下对所得沥青炭进行石墨化处理；测试了所得沥青炭的体积密度、开孔率、比表面积（SBET）；利用扫描电子显微镜（SEM）观察了所得沥青炭的显微结构；利用X射线衍射方法（XRD）检测了所得沥青炭石墨化处理后的石墨化度；测试了所得沥青炭的氧化性能；测试了沥青炭试样的比热容、导热系数、热扩散率和线膨胀系数。结果表明：在92MPa下，两种沥青炭有着相近的密度和开孔率；浸渍剂沥青炭的SBEt高于高温煤沥青炭；浸渍荆沥青炭为流线型结构，高温煤沥青炭为镶嵌型和域型并存的结构；流线型结构沥青炭石墨化度较高；高温煤沥青炭的抗氧化性能要好于浸溃荆沥青炭；随着沥青炭石墨化程度的增大，比热客、导热系数、热扩散率都增大，而线膨胀系数减小。     

浸渍增重率和反渗率研究

对浸溃过程中浸渍剂沥青的浸入率和反渗率进行了分析与探讨。提出了理想增重率、理论增重率与实际增重率的概念和计算方法。并比较了实际增重率与操作增重率的差别。同时分析了抽真空的绝对压力与施压的绝对压力对各项增重率和反渗率的影响。     

3-D hydrodynamics generated in a stirred vessel by a multiple-propeller system

The aim of this study is to optimize the position and the number of propellers in a non-standard tall vessel. Laser sheet flow visualization experiments were carried out for selected geometrical arrangements which produced stable flow patterns and good transport between the propellers. Four double-propeller arrangements corresponding to frequent industrial cases and a three-propeller system have been chosen. Comparison of LDA measurements in the r-z plane, dimensionless global parameters N_Qp, Nt_m, N_p, E_p and spatial distribution of local energy dissipation rate ? shows that a three-propeller system is the most efficient.     

A study of the properties of carbon foam reinforced by clay

A novel carbon foam with high strength and very low thermal conductivity was prepared by thermal treating of coal tar based mesophase pitch mixed with montmorillonite clay. SEM observation showed that less micro-cracking appeared on the cell wall of foam by adding of clay-montmorillonite. Foam mechanical properties were improved and its thermal conductivity was markedly decreased. The compressive strengths were increased by 64%, 96% and 100% when the additive amounts of clay were 2%, 5% and 10% (wt%), respectively. Due to the high thermal insulation and lamellar structure of clay, the thermal conductivity of carbon foam decreases from 2 W/m K to 0.25 W/m K.     

Cinétique de dégagement des matières volatiles lors de la pyrolyse d'électrodes de carbone industrielles

In aluminium plants, the anode baking process is associated with an important release of volatile combustible matter. It is the purpose of this study to investigate the kinetics of the evolution of these volatiles. A large thermogravimetry set-up has been designed in such a way that it could simulate real plant conditions. Samples of two distinct masses have been subjected to pyrolysis at different heating regimes. The loss of weight together with the concentrations of the released gases were recorded on a continuous basis during the temperature rise. Kinetic results were found for methane, hydrogen and tar. No variation of the order of reaction with the heating rate was observed, whereas the activation energy and the pre-exponential factor increased. Furthermore, for the range of sample dimensions studied, it was found that the mass of the solid had no significant influence on the kinetic parameters.     

炭材料生产用煤沥青的流变性能

介绍了流体的特性及其表征，描述了煤沥青的流变性能及其在炭材料实际生产中的意义，综述了煤沥青流变性能研究状况。提出了炭材料生产用煤沥青流变性能研究所面临的课题。     

基于BPNN-PID的风电机组桨距控制分析

变桨控制技术是风力发电机组的核心技术之一,开展对风力发电机组变桨控制方面的研究具有重要的理论和应用价值。根据风力发电机组在额定风速以上如何保持输出功率稳定和降低风轮转速波动的控制技术进行研究,在传统的变桨距控制策略基础上,提出了基于BP神经网络(Neural Network,NN)整定PID的控制策略,并在Matlab/simulink环境下对PID控制和BP神经网络控制相结合的复合控制系统进行建模与分析。对1.5MW风电机组的仿真验证了BPNN-PID算法的有效性,提出算法不仅能够解决传统PID控制器参数整定困难的问题,而且优化效率更高,可以得到优良的控制性能。