浅谈DF4、DF8B型机车牵引电机轴承烧损防止办法

分析了DF4、DF8B型机车牵引电机轴承烧损的原因,指出牵引电机轴承润滑不良是轴承烧损的主要原因,提出了检修方法和改进建议。     

机车轮对横动量对若干问题的影响

通过机车在进入曲线时轮对不同横动量与冲角和附加冲击载荷间关系的分析,论述了减少轮对横动量对减少轮缘磨耗、轴箱轴承烧损、抱轴承挡圈螺栓松脱裂断、抱轴承烧损及抱轴箱体裂纹的影响.     

三轴转向架曲线通过能力分析

SDD22型机车轴式为 C0-C0，中间轴与端轴均采用小轴向间隙的轴箱轴承，为改善机车的曲线通过性能，中间轴采用较小横向刚度的轴箱拉杆。通过计算分析，验证方案的可行性。     

东风7型机车柴油机曲轴轴承烧损原因及预防措施

东风7型机车在保质期内发生曲轴轴承烧损现象比较频繁,文中提供了烧损情况统计,并对烧损原因进行了分析.烧损原因包括保养不当、部件故障、滤清器堵塞、轴瓦质量不高、配合间隙不合适以及柴油机异常振动等.针对具体原因制定了预防措施.     

滚抱结构轴承在组装运用过程中发热烧损的原因分析及改进措施

通过对机车滚抱箱和轴承的结构、组装等方面的分析，阐述了滚抱箱轴承发热烧损的原因并提出了解决措施。     

HXN3型内燃机车主辅发电机轴承故障的分析

针对HXN3型内燃机车主辅发电机轴承异音或烧损等故障现象，对故障电机轴承进行了拆解分析，提出了相应的改进措施和解决办法。     

对北京型机车凸轮轴中间轴承座定位孔位置的探讨

对北京型机车凸轮轴轴承运用中出现的烧损故障进行了分析，指出其烧损的一个主要原因是轴承座定位孔位置不合理。经计算分析给出了修改定位孔的方案，并通过运行试验进行了验证。     

16V280ZJA型柴油机配气惰轮铜套烧损原因及预防措施

通过对16V280ZJA型柴油机配气惰轮轴承烧损原因分析，阐明了原结构设计及工艺上存在问题，提出了改进措施及解决办法。     

内燃机车走行部常见故障救援方法

指出内燃机车走行部有抱轴瓦碾烧、轴箱轴承烧损等7种常见的故障司机无法自己处理,需要请求救援.简要介绍了每种故障的救援处理实用方法.     

一次风机电机轴承损伤的原因分析及处理

神华神东电力热电公司上湾三期2×150 MW工程1号、2号锅炉一次风机的4台电动机,在机组投运初期的几个月内,陆续出现异常声音,振动加大,且声音逐步增大,甚至有轴承烧损的情况,已经严重影响到机组的安全、稳定运行.经分析认为其主要原因是电动机轴电流的存在对电动机轴承的损伤所致.对电动机的轴承端盖进行了改造,切断轴电流产生...     

牵引电动机主动齿轮热套的改进建议

1 问题的提出 牵引电动机主动齿轮系内燃机车走行部传递动力的关键部件之一,它与电机轴的装配形式采用的是圆锥轴过盈配合,在机车满负荷运行时,其承担着列车大约410kW(C型车为480kW)的牵引力。如果机车在运用当中出现主动齿轮松脱或崩裂,特别是机车在低速重载牵引工况下,将导致电机绕组烧损放炮,造成正线机破,严重影响着机车的行车安全。我厂自试修机车以来,主动齿轮厂外松脱、崩裂现象时有发生,尤其是近期连续发生2381号、3541号、3591号、1094号机车因主动齿轮松脱、崩裂造成干线机破事故。这不仅给工厂造成较大的经济损失,而且严重影响着工厂的质量信誉,给用户也带来诸多不便。     

Strategy for selection of elements for heat transfer enhancement

The present paper points out that the selection of elements for heat transfer enhancement in heat exchangers requires a methodology to make a direct comparison of the performances of heat exchanger surfaces with different elements. Methods of comparison used in the past are, in many respects, approximate and hence fail to predict accurately the relative performance of conventional heat exchanger surfaces operated with different heat exchanger elements. Owing to the direct use of the Colburn factor for performance assessment, these methods over-predict the relative performance of heat exchangers. In the present paper, a more consistent comparison method is presented and is demonstrated to work by comparison of the performance of an experimentally investigated pin fin heat exchanger with that of a smooth pipe heat exchanger. The method yields results that belong to the volume goodness factors group. It represents a practical approach, as it is applicable to all kinds of heat exchanger surfaces and does not require the conversion of the experimental data in terms of Nusselt number and friction factor for comparison purposes. The present work demonstrates that the suggested method can also be used for performance comparison of existing heat exchanger surfaces with available heat transfer and pressure loss data.     

Strategies for selection of thermo-chemical processes for the valorisation of biomass

Research on biomass conversion has been gaining a lot of interest as biomass is renewable and sustainable in nature. Products from biomass can be obtained by different methods amongst which thermo-chemical route has a very high potential. Biomass is generally available in a localised manner in varying quantities and qualities throughout the year and hence, region specific technologies have to be developed considering the end user requirement. Pyrolysis is a very versatile technique with the above considerations. The process parameters can be tweaked to necessity to produce more bio-oil or bio-char. Thermogravimetric analysis is essential for understanding the decomposition behaviour of the feedstock before the lab scale pyrolysis is carried out. Pyrolysis using several regional feedstocks has been carried out under nitrogen and hydrogen atmosphere and different biomass feedstocks were also liquefied using sub/supercritical solvents. This review aims to provide a comparison of the results obtained using various processes. This helps in the decentralised processing of biomass (dry biomass using pyrolysis and wet biomass by hydrothermal liquefaction) to produce bio-crude which can be upgraded to produce fuels/chemicals/petrochemical feedstocks in an environmental friendly manner.     

Quantitative evaluation for effective removal of phosphorus for SoG-Si

Production of solar cells has increased rapidly in recent years, and metallurgical production of solar grade silicon (SoG-Si), has increased compared with more expensive processes such as Siemens process and Cz processes. It is important to understand the thermodynamic behavior of phosphorus in slag for optimized refinement of SoG-Si. In this study, the thermodynamic behavior of phosphorus in the CaO-SiO₂-CaF₂ slag system was investigated at 1773 K for various oxygen potential and slag composition. In addition, evaporation of phosphorus in the reduction process was observed during slag refining by addition of H₂ gas.Experimental results showed that the stability of phosphorus in slag depends on both the O²⁻(basicity) content of the slag and the solubility of Ca in silicon, and the dissolution mechanism of phosphorus into slag was derived. Results confirmed that phosphorus and calcium in molten silicon were also removed by acid leaching. The effective removal of phosphorus for SoG-Si using several refining processes was evaluated quantitatively.     

锅炉锅筒吊杆销轴强度校核计算程序

锅炉锅筒吊杆销轴强度校核一直是一个比较烦琐的计算过程，重复性大，通过用计算程序，可减轻劳动强度，节省劳动时间，满足生产需要。     

Application of scanning mid-IR-laser microscopy for characterization of semiconductor materials for photovoltaics

Scanning mid-IR-laser microscopy was previously demonstrated as an effective tool for the characterization of different semiconductor crystals. Now the technique has been successfully applied for the investigation of CZ Si_xGe_1−x – a promising material for photovoltaics – and multicrystalline silicon for solar cells. In addition, this technique was shown to be appropriate for the imaging of polishing-induced defects as well as huge defects such as “pin holes”. Besides, previously unexplained “anomalous” (cubic power) dependence of signal of the scanning mid-IR-laser microscope in the optical-beam-induced light scattering mode on the photoexcitation power obtained for mechanically polished samples has now been attributed to the excess carrier scattering on charged linear defects, likely dislocation lines. The conclusion is made in the article that scanning mid-IR-laser microscopy may serve as a very effective tool for defect investigations in materials for modern photovoltaics.     

铁路货车回转阻力矩计算方法初探

回转阻力矩作为货车转向架的一项重要技术参数,在铁路货车的设计中具有举足轻重的地位,其取值的大小直接影响转向架的动力学性能。分析了货车转向架回转阻力矩的典型形式和计算的基本原理,推导了平面心盘、球面心盘的摩擦阻力距计算公式。并以转K6型转向架和Y25型转向架为例,对旁承摩擦阻力矩、平面心盘和球面心盘摩擦阻力矩进行了详细的计算。     

锅炉机械不完全燃烧损失q4解析评估模型研究

针对传统计算机械不完全燃烧损失不利于在线耗差寻找的问题 ,通过理论推导和试验分析研究 ,推导出基于煤质特性与运行特性的锅炉机械不完全燃烧损失解析评估模型 ,实现了造成 q4 变化之因素的定量寻找。并分别以煤质特性参数可燃基挥发分Vdaf和运行特性参数炉膛出口过量空气系数αl 为例 ,验证了模型的精确性 ,为节能降耗提供依据     

Guidelines for assessment of investment cost for offshore wind generation

Offshore wind generation represents a key element for development of renewable energy, thanks to higher availability of energy source and lower presence of constraints. However, the feasibility of offshore wind farms has to be carefully evaluated, due to remarkable economical efforts required. In this paper, economic issues concerning costs in pre-investment and investment stages for offshore wind farms exploiting alternating-current transmission system are analysed. Single cost centres are detailed, taking into account technical features and current equipment exploitation. The aim is to formulate a general model to evaluate the total investment depending on wind farm layout. The model is employed to determine the most suitable connection solution for a 150-MW test wind farm, accounting for different connection schemes and the presence of an offshore or onshore substation. Further tests are run to evaluate cost variation for larger wind farms with different nominal voltage levels.