关联维数在往复压缩机气阀故障诊断中的应用

针对传统方法难以有效进行往复压缩机气阀故障诊断的现状,提出了应用关联维数对往复压缩机气阀故障进行诊断的方法。通过对气阀常见故障类型的诊断,表明关联维数可以有效地分析出往复压缩机气阀的常见故障。     

湍流状况下的管式反应器中的速度时间序列关联维数分析

通过激光多谱勒测速仪(LDA）测得管式反应器中不同流点的速度时间序列，提出了关联维数在分析湍流场的速度时间序列的应用方法，并且得到关联维数在管式反应器中的径向和轴向的变化范围大约在1．5-2．5之间。随雷诺数Re的变化，关联维数的变化范围在1．0-2．5之间，由此可以推测关联维数为2．5有可能是湍流变化的一个临界值。提出关联维数可以用来判断涡漩的能量随时间的衰变阶数。通过使用这一方法扩展了研究湍流的思路，并且提出使用关联维数来判断湍流的可能性。     

高分子复合材料断面的三维分形维数的计算方法

高分子复合材料的断面形貌呈现出自相似性和自放射性,具有分形特征,可用分形维数来定量描述。文中讨论了结构函数法、像素点覆盖法和投影覆盖法计算高分子复合材料断面的三维分形维数的原理、方法和步骤,对比分析了三种方法的准确性。最后指出了将来的研究方向。     

均匀设计及其在氢气制备中的应用

均匀设计试验法是一种应用于多因素、多水平试验研究的新方法。在氢气的制备中运用该方法设计试验方案,可方便地找出最佳实验条件的组合,氢气收率接近１００％。     

PVC树脂粘数计算方法的探讨

1粘数的测定 1.1溶液的制备 称(0.125±0.005)g干燥均匀树脂于锥形瓶中,准确至0.000 2 g,加入一定量的环己酮,配成0.005 g/mL的溶液.同时用手轻轻摇动以免凝结成块,并在恒温水浴中保持80～85℃,溶解1 h,溶解完全后,取出锥形瓶冷却至室温,待用.     

输入训练神经网络的维数约简算法及其在化工过程建模中的应用

Many applications of principal component analysis （PCA） can be found in dimensionality reduction. But linear PCA method is not well suitable for nonlinear chemical processes. A new PCA method based on improved input training neural network （IT-NN） is proposed for the nonlinear system modelling in this paper. Momentum factor and adaptive learning rate are introduced into learning algorithm to improve the training speed of IT-NN. Contrasting to the auto-associative neural network （ANN）, IT-NN has less hidden layers and higher training speed. The effectiveness is illustrated through a comparison of IT-NN with linear PCA and ANN with experiments. Moreover, the IT-NN is combined with RBF neural network （RBF-NN） to model the yields of ethylene and propylene in the naphtha pyrolysis system. From the illustrative example and practical application, IT-NN combined with RBF-NN is an effective method of nonlinear chemical process modelling.     

计算TCaco3的一种简便方法及误差分析

在水泥生产控制中,生料TCaco_3的测定是重要的控制项目,它要求快速、准确。测定的方法,是酸碱返滴定法。由于测定的频数高,计算较麻烦,下面介绍一种只通过加、减法就可求得TCaco_3的简便方法供参考。     

一种混合球罐极板的计算方法

根据混合球罐极板上各球壳板的形成原理,推导出一种简单易记的极板计算方法。     

FRACTAL STUDIES IN A SELF-ASPIRATED REVERSED FLOW JET LOOP REACTOR

1 INTRODUCTIONSelf-aspirated reversed flow jet loop reactors,characterized by a well defined flow pat-tern,well better dispersing effects,relatively low power consumption and a high masstransfer coefficient,are widely used in chemical engineering,especially in biochemicalengineering.The characteristics of such reactors are highly random or stochastic due tothe influence of a variety of phenomena such as jetting and bubbling of the fluidizing     

脱氯剂及其在合成氨和制氢工业中的应用

绍氯对合成氨、制氢装置及后序催化剂的危害，国内外常用脱氯剂的型号及性能。在探明脱氯剂脱氯机理的基础上，探讨了操作条件对脱氯剂性能的影响和国内脱氯剂的工业应用现状。     

WALL JET DEVELOPMENT IN A TURBULENT RECIRCULATING CAVITY FLOW

A turbulent wall jet within a confining recirculating cavity was examined using flow visualization, particle image velocimetry (PIV), and laser Doppler velocimetry (LDV). The PIV technique was used macroscopically for flow visualization as well as at a much finer resolution to determine detailed velocities within the developing wall jet. Comparison data collected using laser Doppler velocimetry (LDV) was used for validation purposes. The wall jet was well characterized using conventional unbounded wall jet parameters. Wall jet velocity profiles collapsed onto a single profile with the application of the appropriate parameters, indicating some degree of similarity after the initial jet region and up to the mid wall distance. Distances past this region were characterized by a rapid decay in the jet caused by the adverse pressure gradient created by the bounding wall. It was found that the wall jet growth rate within the recirculating cavity was greater than that of an unbounded wall jet in a stagnant fluid. This phenomenon is attributed to the recirculating flow, confining boundaries, and the initial jet exit velocity conditions.     

WALL JET DEVELOPMENT IN A TURBULENT RECIRCULATING CAVITY FLOW

A turbulent wall jet within a confining recirculating cavity was examined using flow visualization, particle image velocimetry (PIV), and laser Doppler velocimetry (LDV). The PIV technique was used macroscopically for flow visualization as well as at a much finer resolution to determine detailed velocities within the developing wall jet. Comparison data collected using laser Doppler velocimetry (LDV) was used for validation purposes. The wall jet was well characterized using conventional unbounded wall jet parameters. Wall jet velocity profiles collapsed onto a single profile with the application of the appropriate parameters, indicating some degree of similarity after the initial jet region and up to the mid wall distance. Distances past this region were characterized by a rapid decay in the jet caused by the adverse pressure gradient created by the bounding wall. It was found that the wall jet growth rate within the recirculating cavity was greater than that of an unbounded wall jet in a stagnant fluid. This phenomenon is attributed to the recirculating flow, confining boundaries, and the initial jet exit velocity conditions.     

NUMERICAL PREDICTION OF A RECTANGULAR TURBULENT JET IN A CROSS FLOW

The trajectories and decay of the maximum velocity for turbulent jets in a cross flow were simulated by means of the κ — ? two-equation turbulence model in which differential equations were solved for the kinetic energy of turbulence and for the rate of its dissipation. The solution procedure employed an elliptic finite-difference scheme with the three velocity components and the pressure as the main dependent variables. The essential properties of the jet were discussed in the case of different ratios of the rectangular orifice length to the width H/B, ratios of the jet injected velocity to the main stream velocity R; and different injection angles α. The numerical prediction results were presented in the form of equivalent diameter. Lastly, two correlation equations were obtained and the numerical predictions are shown to agree well with the experimental data.     

GSP加压气流床气化技术及其在中国的应用前景

ＧＳＰ加压气流床气化技术是近年来投入商业化运行的新一代大型先进气化技术之一,由前东德的德意志燃料研究所开发。该气化技术采用气化炉顶干粉加料、氧气气化、炉底液态排渣。本文在介绍了该气化技术的开发历程、气化炉结构、工艺流程及技术特点的基础上,分析了该气化技术在中国的应用前景。     

下喷自吸环流反应器中气-液局部相际传质模型

引言 下喷自吸环流反应器是在结合喷射、环流、自吸等优点基础上而开发出的一种新型高效反应器,开展该反应器内局部气液传质模型的研究,对于该反应器的优化设计及放大具有极重要的理论意义.多年来,经典传质理论的不足与局限都在经历不断的修正与改进.其中,激光多普勒测试在传质研究中的应用使得人们对湍流在传质中的重要性有了     

甲醇裂解制氢工艺及其在林产化工中的应用

阐述了甲醇裂解制氢工艺以及在氢化松香和对孟烷生产中的应用 ,并经生产实践证明 ,具有明显的经济和社会效益。     

LOCAL LIQUID SIDE MASS TRANSFER MODEL IN AIRLIFT LOOP REACTOR AND SELF-ASPIRATED REVERSED FLOW JET LOOP REACTOR

Combining Higbie's penetration theory and Kolmogoroff's theory of isotropic turbulence, a small-scale isotropic mass transfer model for the local liquid side mass transfer coefficients in a gas-liquid two-phase airlift loop reactor and a self-aspirated reversed flow jet loop reactor has been developed. Good agreement with the experimental data suggests a general applicability of the proposed model in these reactors.     

新型复合塔板JCPT的性能及工业应用

对一种新型高效复合塔板———喷射式并流填料塔板（ＪＣＰＴ） 分别采用空气水系统和乙醇水系统进行了流体力学和传质性能研究,并给出了适用于工业设计的板压降、漏液、雾沫夹带等性能参数的关联式。同新型垂直筛板（ＮＶＳＴ） 相比,ＪＣＰＴ具有压降低、操作弹性大、通量大、效率高等优点。同时给出了工业应用实例。