DJND型轮缘踏面在东风5型机车上的应用

东风5型内燃机车已被广泛应用于大型机械化驼峰编组站,但作业时存在着轮箍踏面非正常磨耗严重的问题.经分析后,对其轮箍踏面形状进行了改进处理,将原有的锥型踏面改用为DJND型,改型后的轮箍踏面非正常磨耗量减少了36%,取得了良好的效果.     

25t轴重机车磨耗形踏面的研究

在对运用中的25t轴重东风8B型机车车轮踏面实测的基础上,分析了25t轴重机车磨耗形踏面的特点。为了实现在大轴重下轮轨的合理几何匹配,较大地减缓轮缘与钢轨的磨损,根据实测的车轮踏面外形,参考国外大轴重的磨耗形杯准踏面,从我国铁路的实际情况出发,设计了25t轴重的机车磨耗形踏面(ST3型),以改善轮轨相互作用,延长车轮与钢轨的工作寿命,试图为我国铁路25t轴重内燃机车及电力机车的大批量推广应用,解决一个关键的技术问题。     

减缓25t轴重DF8B型机车车轮磨耗的试验研究

根据对25t轴重的DF8B型机车车轮磨耗形状的实测,设计并试制了适用于该轴重的磨耗形踏面(ST2G型)样板。从2000年4月起,已在配属于南翔机务段的27台DF8B型机车上装用该型踏面车轮,其中2台已走行一个中修期(分别为28 4万及28 6万km),5台已走行15万～20万km。运行实践表明,ST2G型踏面车轮取得了轮缘减磨20%～33%,踏面减磨25%～30%的良好效果。     

ST2型踏面车轮在DF11型机车上的应用

根据轮轨几何的理论分析 ,ST2 型踏面轮对与 6 0kg/m轨相匹配 ,它的等效斜度λe 在横向位移yw=1～ 7mm时是 0 1,而yw>7mm时λe=0 3。这一特性表明 ,ST2 型踏面车轮不但具有好的曲线减磨效果 ,并且能以较高速度在直线上平稳运行 ,适合于提速机车的运行要求。上海机务段自 1999年 3月开始至今 ,已在沪宁、沪蚌线运行的 4 7台DF11型机车上先后装用ST2 型磨耗形踏面车轮 ,用以牵引快速列车 ,机车振动情况正常。为了实际测定DF11型机车装用ST2 型踏面车轮的振动性能 ,经用英国生产的MKⅡA型测振仪在司机室中央地板处测得它的横向振动平衡性指标W2 ,在 90～ 14 0km/h范围内 ,处于优良及合格水平。理论和实践均证明 ,ST2 型踏面车轮 ,用于14 0km/h的提速机车上是合适的 (由于运转时分限制 ,测试的最大速度为 14 0km/h)。值得指出的是 ,采用ST2 型踏面车轮牵引快速列车 ,有减缓车轮踏面剥离及轮缘磨耗的好处 ,而踏面剥离及轮缘过早磨耗正是提速机车落轮修的主要原因。     

踏面下凹磨耗对地铁车辆动力学性能的影响

铁道车辆在运行的过程中由于各种因素的作用车轮踏面磨耗呈现下凹趋势,这种凹形磨耗称为下凹磨耗.为了表征踏面下凹磨耗对地铁车辆动力学性能的影响程度,针对某一地铁车辆建立了多体动力学仿真模型,计算分析了3种磨耗工况下列车运行稳定性、平稳性和安全性指标.分析结果表明,随着车轮踏面下凹磨耗深度的增大,列车稳定性、平稳性变差,且在一定程度的磨耗范围内这种下凹磨耗的趋势有利于列车曲线通过.     

机车轮对JM、JM2、JM3磨耗型踏面及其剥离

机车轮对踏面剥离的产生因素很多,如轮箍材质、高速重载、制动过热、踏面型式,等等。对20世纪80年代以来南宁铁路局已应用过的机车轮对JM、JM2、JM3磨耗型踏面的剥离问题,作了比较和探讨。     

独立旋转车轮踏面设计

阐述了独立旋转车轮踏面设计方法,并根据50kg／m钢轨轮廓设计了新型踏面。轮轨接触几何分析以及动力学计算结果表明,其与LM磨耗型踏面相比,轮轨接触点分布合理,独立旋转车轮动力争陛能得到改善。     

应用随机减量和模态分析方法辨识机车轮对模态和物理参数

讨论了轮对横向振动中参数的随机减量时域识别方法,从轮对随机响应中提取自由响应,识别出物理参数;以锥型踏面和磨耗型踏面的情况分别为例进行了分析,并提出了随机减量函数的提取方法,计算结果表明,具有较高的精度.     

铁路机车轮对综合参数自动检测系统

针对铁路机车轮对检修的要求,研制了机车轮对综合参数自动检测系统,该系统能完成对轮缘磨耗、踏面磨耗、踏面擦伤等重要参数的自动测量,从而提高了机车轮对检测的自动化程度及轮对检修作业的效率.     

ZLPM-I型自动轮喷控制装置在DF8B型机车上的应用

介绍了ZLPM-I型自动轮喷控制装置的工作原理及其特点.该装置对减少机车轮缘、踏面磨耗,减少机车旋修次数,缩短机车检修库停时间有一定的效果.     

基于混合智能算法考虑时序性的风光电源多目标规划

随着分布式电源(Distributed Generation,DG)在配电网中被越来越多的应用,探究分布式电源的选址定容问题成为研究的热点。为降低配电网负荷及DG出力时序特性对DG规划的影响,文章分析了负荷和DG出力时序特性曲线,建立了多目标数学模型,利用层次分析法对多目标函数处理,采用遗传--模式搜索混合智能算法(IGABPS)进行一年全时段寻优求解。最后采用IEEE33节点系统对方案进行验证,算例结果表明了考虑时序特性的规划方案更能真实反映配电网的实际运行情况。     

Complex-valued forecasting of wind profile

This paper presents a novel approach for the simultaneous modelling and forecasting of wind signal components. This is achieved in the complex domain by using novel neural network algorithms and architectures. We first perform a signal nonlinearity and component-dependent analyses, which suggest the use of modular complex-valued recurrent neural networks (RNNs). This RNN-based modelling rests upon a combination of nonlinearity, complexity and internal memory and allows for the multiple step ahead forecasting of the wind signal in its complex form (speed and direction). The approach is first verified on benchmark Data Set A (NH₃ laser data) of the Santa Fe Time Series Prediction Competition together with artificial data generated by chaotic Mackey–Glass equations, and then applied to the real-world wind measurements. Simulations support the proposed architecture and algorithms.     

磨耗形踏面的试验推广效果

1问题的提出 大连机务段配属的内燃机车担当大连至苏家屯干线货运及大连至城子坦、大连至旅顺支线的客、货运输任务.大连至苏家屯间干线最大坡度12.3‰,最小曲线半径500m;大连至城子坦、旅顺的支线线路条件远远不如干线,曲线多且半径小.     

Dielectric properties and temperature profile of fly ash-based geopolymer mortar

In this paper, the fresh properties, dielectric properties and temperature profile of fly ash-based geopolymer mortars are investigated to observe the effect of mixture proportions and time after mixing. Sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃) were used as the activators. The results of fresh properties revealed that the added water could improve the workability of geopolymer mortar. It is also found that the initial and final setting times of all the geopolymer mortars are less than those of cement mortars. For the dielectric properties and surface temperature, mortars were measured during a 24-hours geopolymerisation period at room temperature. The obtained results show that dielectric properties and surface temperature of geopolymer mortars tended to decrease with increasing time after mixing. And the geopolymer mortars had the highest value of dielectric properties and surface temperature at right after mixing. In addition, the dielectric properties (ε_r' and ε_r″) of the specimens with more liquid constituents were also higher. In particular, this work shows that it is possible to cure the fly ash-based geopolymer mortars with microwave energy depending on the mixture proportion and time after mixing.     

圆弧端齿加工方法及齿形误差分析

结合HXD3B型机车驱动系统的结构特点，对圆弧端齿的结构进行深入分析。通过分析圆弧端齿的齿形加工方法，对圆弧端齿的齿廓方程进行了较深入的理论研究，得出圆弧端齿齿廓方程以及圆弧端齿大端、齿长中部及小端齿顸的厚度差，从而确定圆弧端齿齿面的精确几何形状。     

Transient temperature profile inside thermoacoustic refrigerators

The linear theory used to calculate the thermal quantities inside the stack in the classical thermoacoustic refrigerators always overestimates those measured. The causes of these discrepancies have to be found in the complex processes of thermal exchanges. The analytical study of the transient response should provide an interpretation of these complex processes. This present paper provides such analytical modelling. This modelling remains within the framework of the classical linear theory. It includes the effects of the thermoacoustic heat flux carried along the stack, the conductive heat flux returning in the solid walls of the stack and through the fluid inside the stack, the transverse heat conduction in the stack and the heat leakages through the duct walls, the heat generated by viscous losses in the stack, the heat generated by vorticity at the ends of the stack, and the heat transfer through both ends of the stack. A modal analytical solution for the temperature profile is proposed, assuming the usual approximations in such thermal problems to avoid intricate calculations and expressions. The theoretical transient response of a thermoacoustic refrigerator is compared with experimental data. A good qualitative agreement is obtained between analytical and experimental results after fitting empirical coefficients.     

铁道车轮外形测量仪的软件设计研究

铁道车轮外形测量仪主要用来测量车轮外形,显示重要参数,绘制测量曲线。通过参数和实际测量曲线查看车轮磨损情况,在列车运行安全方面尤为重要。对车轮外形测量仪的软件设计进行了研究。对软件开发平台EVC和车轮外形测量仪的系统结构做了简单介绍,给出主程序流程图。对程序运行后的功能实现给予详细介绍。     

凝汽器最有利真空的确定和最佳工况图

通过对福建永安电厂凝汽器进行试验，取得在各种条件下的特性数据，分析主要参数对凝结器真空的影响，确定凝汽器的最佳工作状态，也就是指导运行人员操作的“最佳工况图”。     

Analysis of point-focused,non-imaging Fresnel lenses' concentration profile and manufacture parameters

The purpose of this study is to develop a mechanism of a curve-based, point-focused Fresnel lens concentrator system and use it to examine each spectral segment's distribution patterns on the lens' focal area. The mechanism incorporates optical geometry and ray tracing technique with the components of solar spectrum, refractive index information of lens materials, and the formulation for quantifying the concentrator systems' transmittance loss and prism-tip dispersion loss. In addition to the facet angles' role in refracting the incoming radiation, this research has addressed spectrum-filtering role of the side angle, the angle between the entry face and the side face of each facet on the lens. The theoretical aspect has been elaborated on the basis of the lens' design wavelength. A computerized model has been developed and the simulated outcome compared to the measured data from a previous research. The result of this study provides the information of illumination patterns under a circular lens, which will help to match up various spectrum distributions to their suitable solar applications.