PTA干燥机填料异常磨损故障分析

对干燥机填料故障的主要原因进行了深入分析,指出了故障内在原因,干燥机密封填料的聚四氟乙烯盘根编织型式不合适,造成其磨损溃散污染物料,建议选用抗磨损溃散性更优异的穿心编织型式填料盘根。     

载货汽车轮胎异常磨损的原因及解决措施

轮胎为橡胶制品,胎冠部位与地面接触产生摩擦,形成对整车的驱动力,存有不均匀分布的异常磨损现象,对此进行探讨.     

滑阀磨损原因及预防措施浅析

文章介绍了滑阀的结构特点、工艺性能和使用情况。根据滑阀阀杆、阀板等部件的磨损现象,结合行业经验,从滑阀的结构设计、衬里结构、制造材质和生产操作等方面详细分析了滑阀的磨损原因,剖析了滑阀吹扫蒸汽、限流孔板的使用在滑阀使用中的作用等热点问题,提出了预防滑阀磨损的措施。     

切粒刀异常磨损原因分析及处理

挤压造粒机中切粒刀由于异常磨损,切粒刀损耗大,通过降低切粒刀进刀风压,提升转速,并研磨修复模板造粒带等措施,切粒刀异常磨损情况得到了有效控制。     

航空发动机磨损趋势预测模型研究

文章讨论了神经网络的BP算法和遗传算法,提出用遗传算法来优化BP神经网络,应用遗传算法训练神经网络权重,实现网络结构的优化,用优化后的BP人工神经网络建立了航空发动机磨损故障趋势预测模型,利用发动机的光谱监测数据作为预测磨损趋势的特征参数,进行了模型的训练和预测试验,并将该模型预测结果与BP算法和多元线性回归法的预测结果进行了比较,证明了基于遗传算法的人工神经网络是航空发动机磨损故障趋势预测的一种理想方法。     

磨机衬板与磨球配合磨损的实例浅析

1 引言球磨机衬板与磨球是水泥生产的易损件。磨机工作时,衬板受到磨球和物料的抛落冲击而磨损,还受到磨球的滑动磨损;磨球则受到衬板反作用的磨损、物料的磨损和磨球之间的磨损,它们之间相互作用又相互影响。在实践中,我们发现材料的硬度与耐磨性呈相关性,耐磨性随着硬度的提高而提高;同时还发现磨球和衬板是一对摩擦付,一方硬度提高则另一方磨损加快。因此,正确选择衬板与磨球配合工作,做到磨球耐磨的同时又对衬板的磨损最少,这关系到企业的效     

柱塞泵蜗轮箱异常磨损的原因分析及改进

分析柱塞泵运行中蜗轮箱产生异常磨损和零部件失效的原因,进行了技术改进和旧件的修复夏利用后,泵运行正常,减少了维修工作量,取得了较好的经济效益。     

关于发动机机体气缺套承孔磨损分析及解决办法

一批ＣＡ１４１型汽车发动机缺体的气缸套承孔在使用过程中出现了内径变大,新的标准缸套无法配合作用。经验查分析,发现为微动磨损所致。为此,我们采用表面镀铜进行电刷镀缸套和加大其外径的修复,实践证明,使用效果相当好。     

飞机发动机磨损状态直读铁谱监测判据选择研究

文章简要介绍了直读铁谱监测的判据,在此基础之上应用直读铁谱技术,对苏-27飞机发动机滑油油样进行测定,并对所得数据进行梳理分析,得出各直读铁谱监测判据随飞机发动机运行时间的变化规律,最后,确定了对飞机发动机磨损状态的变化反映最灵敏的判断依据。     

Dynamometer evaluation and engine wear characteristics of palm oil diesel emulsions

Dynamometer engine tests at steady-state conditions and a wear characteristics study were carried out on an indirect-injection diesel engine with palm oil diesel (POD) and its emulsions. The POD fuel was obtained in commercial form, and its emulsions were created by mixing POD fuel to contain 5 and 10% of water by volume. Variations in the engine’s performance characteristics were determined from the results of steady-state tests carried out at fifteen selected torque-speed matrix points of the engine’s performance map. The wear characteristics tests were performed by running the engine at half throttle setting for twenty hours for each fuel system. Then a desk-top comparison study was performed between the base-line fuel system of ordinary diesel (OD), POD, and its emulsions. Promising results have been obtained. Neither the lower cetane number of POD fuel nor its emulsification with water presented obstacles to the operation of the diesel engine during a series of steady-state engine tests and the twenty-hour endurance tests. Engine performance and fuel consumption for POD and its emulsions are comparable with those of OD fuel. Accumulations of wear metal debris in crank-case oil samples were lower with POD and its emulsions than with baseline OD fuel.     

A rapid test to measure performance,emission and wear of a diesel engine fueled with palm oil diesel

Results of performance, emission and tribological evaluations of palm oil methyl ester and its blends with conventional diesel in an automobile diesel engine test bed are presented. Polymerization and carbon deposits on the fuel injector were monitored. CO, CO₂, O₂, combustion efficiency and temperature of exhaust gases were also measured. Palm oil methyl ester and its blends have great potential as alternative diesel fuel. Performance and exhaust gas emission for palm oil methyl ester and its blends with conventional diesel are comparable with those of conventional diesel fuel. Palm oil methyl ester does not pose a severe environmental problem and will not deteriorate engine and bearing components.     

MAN chooses GRP for diesel engine cooler

ENGINE manufacturer MAN has replaced metal with glass reinforced polyamide (PA) 66 in part of its latest air cooling units.This is a short news story only. Visit www.reinforcedplastics.com for the latest plastics industry news.     

Modeling nano-particle deposition in diesel engine filters

In this work, we develop a simple, fully analytical one-dimensional model based on lubrication theory to predict nano-particle deposition along the unit channel of a clean diesel particulate filter. Soot deposition along the channel depends on filter design parameters, which can be optimally selected to minimize the uneven distribution of soot. At the initial stage of the filtration process, the porous wall resistance is controlling; at later stages, the local resistance of the deposited soot is controlling. Typically, a hundredfold increase in filter resistance may be observed over time, and the maximum variability in the soot deposition is observed at the initial stages of the process. Therefore, in this work, we focus on the deposition of soot in a clean filter, focusing on the one dimensional variability along the main flow direction. In a clean filter, the porous wall resistance can be considered uniform along the filter length and the flow field and nano-particle transport equations can be solved analytically. Model predictions compare surprisingly well with those obtained from more complex three-dimensional simulations, thereby demonstrating that the essential physics is captured correctly. Based on the very simple framework identified in this paper, more complex models can be developed and used to predict the filter behavior over time (i.e. build-up of the soot cake and back-pressure rise up to the regeneration step) provided that (i) the variation in time of filter permeability due to local soot loading is implemented and (ii) equations are solved numerically.     

减少柴油机排气污染的化学方法

柴油机、汽油机燃烧过程排放物主要有CO、HC、NOx、SOx及粒子等 ,而柴油机排气中的有害物远低于汽油机 ,但高于汽油机加三元催化剂体系。本文重点介绍了柴油机排气中NOx和粒子的治理方法     

低温等离子体用于柴油机尾气脱硝的实验

柴油机作为卡车、重型机械以及船舶的主动力装置仍被广泛采用,其尾气中氮氧化物的脱除技术也是目前的研究热点。本文搭建了模拟柴油机尾气的配气系统,采用介质阻挡放电产生低温等离子体（non-thermal plasma,NTP）的方法对模拟柴油机尾气进行了脱硝的实验研究。实验结果表明：针对本系统,电源效率和能量密度随着输入电压的增大而升高,当输入电压高于60V时,电源效率在90%以上;在O₂/N₂条件下,随着O₂浓度以及能量密度的增加,NO生成量逐渐增加,NO₂生成量先增加后降低最终趋于稳定;在NO/N₂条件下,低温等离子体对NO的脱除率接近100%;在NO/O₂/N₂条件下,随着NO浓度的增加,临界O₂浓度升高,O₂体积分数为1%时脱硝效率在90%以上,O₂体积分数高于14%时低温等离子体的脱硝率为负值,且随着能量密度的增加,生成的NO _x 浓度也更高,O₂浓度对低温等离子体的脱硝性能起决定性作用;在低能量密度时,加入NH₃会提高脱硝性能,高能量密度时NH₃会略微降低NTP的脱硝性能,当加入H₂O模拟真实柴油机尾气成分且喷氨时,获得的脱硝率最高为40.6%。     

Study on the application of DME/diesel blends in a diesel engine

In this paper fuels, based on various DME to diesel ratios are investigated. Physical and chemical properties of DME and diesel display mutual solubility at any ratio. The vapor pressure of DME/diesel blends is lower than that of pure DME at the same temperatures and it decreases with an increase of diesel mass fraction in blends, which is beneficial to the elimination of vapor lock in the fuel supply system on CI engines. Performance, emission and other features of three kinds of DME/diesel blend fuels and diesels are evaluated in a four-cylinder test engine. By taking relative advantages of DME and diesel, the DME/diesel blends could achieve satisfactory properties in lubricity and atomization, which contributed to improvements in spray and combustion characteristics. Simultaneously, smoke emission could be reduced significantly with a little penalty on CO and HC emissions for DME/diesel blended engine at high loads, in comparison to diesel engine. NO_x emissions of the engine powered by DME/diesel blends are decreased somewhat. Moreover, the power output would be improved a little and NO_x emission could be reduced further if the fuel supply advance angle is retarded appropriately.