GK1C型机车闸瓦偏磨的原因分析及处理

针对GK1C型机车由于采用杠杆系统制动的基础制动装置,在机车运行中摆动较大造成的闸瓦偏磨现象进行原因分析,并采取有效措施,基本解决了此问题。     

SDD6型机车断钩分离自动保护装置的应用

介绍了断钩分离装置在SDD6型机车JZ-7型空气制动机上的使用情况,该装置解决了机车断钩后不能有效制动的问题,提高了机车的安全性能。     

DF10D型机车DZD型制动单元防偏磨闸瓦装置的研究与应用

莱芜钢铁集团有限公司针对国产DF10D型机车装备的DZD型制动单元,自行研制并运用了适于该型制动单元的防偏磨闸瓦装置,解决了原制动单元频繁发生闸瓦外侧偏移磨耗问题,提高了机车的运行可靠性,降低了总体运营成本。     

简化空气管路的JZ-6型制动机制动系统

介绍了CKD8G型机车安装的简化空气管路的JZ-6型制动机,机车只牵引真空制动的车辆时,在保证真空制动性能的情况下,取消了空气中继阀、分配阀、作用风缸、压力风缸、无火回送装置及相应管路部分。简化空气管路的JZ-6型制动机制动系统原理简单、清楚,方便机车的制造、使用和检修。     

机车制动监测系统中传感器结构的研究

对机车制动监测装置中的传感器作了较深入的研究,设计出了适用于机车制动状态检测的开关型传感器和压力传感器。给出了几种传感器的设计安装方法,并对各种传感器结构特点作了比较。     

新一代八轴机车制动系统开发和集成

介绍了新一代八轴机车制动系统平台的开发和集成,并对风源系统、制动控制系统、基础制动装置的控制原理、主要部件的功能和技术参数进行了分析探讨。     

浅析国产客运提速机车基础制动装置现状

分析了国产客运提速机车的踏面闸瓦制动装置的性能、结构以及存在的问题,提出了适应提速要求的机车盘形制动装置方案.     

关于内燃机车行车安全设备的两项改进

1问题的提出莱芜钢铁集团有限公司运输部现有内燃机车25台,自2005年开始到2006年底,在所有机车上都安装了行车安全设备。该设备由LKJ．93A型列车运行监控记录装置、Js型数字化通用式机车信号系统、机车速度系统和机车制动系统组成。     

对机车闸瓦开发的探讨

从摩擦制动产生热的角度提出"摩擦形式假说”,指出受摩擦状态的影响,制动摩擦中摩擦面积与摩擦结果相关,探讨采用制动功率来设计机车闸瓦和基础制动装置的问题.     

SDD1型机车轮箍弛缓原因分析及改进

通过对运用环境、设计参数、组装过程控制、基础制动装置、轴箱拉杆装配和机车操作与维护等方面的分析,指出了造成SDD1型机车轮箍弛缓的根本原因是恶劣的运用环境,并通过改进设计参数和设计结构、加强组装过程控制和售后服务等措施以适应恶劣的运用环境,从而彻底解决了这一重大质量问题。     

原东德EDK300/2型60t铁路起重机制动系统改造设计

简要介绍了原东德EDK300/2型60 t铁路起重机空气制动系统和基础制动装置等,研制出一种适合于铁路起重机的制动系统。对其改造方案、具体结构和计算分析进行了阐述。经改造后的制动系统能够满足运营要求。     

新一代机车制动机方案研究

简要介绍了微机控制的机车制动控制系统的形式和特点,分析了新一代机车制动机的结构形式及其功能。在此基础上,提出了新一代机车制动机方案。并对该方案的系统组成和作用原理进行了介绍。     

Impacts of additives on performance and emission characteristics of diesel engines during steady state operation

Depletion of fossil fuel resources and stringent emission mandates has spurred the search for improved diesel engines performance and cleaner combustion. One of the best approaches to solve these issues is to use biodiesel/diesel additives. The effects of biodiesel/diesel additives on the performance and emissions of diesel engines were comprehensively reviewed throughout this article. The additives reviewed herein were classified into five categories, i.e., oxygenated additives, metallic and non-metallic based additives, water, antioxidants, and polymeric-based additives. The effects of each category on the engine performance (i.e., brake specific fuel consumption (bsfc) and brake thermal efficiency (bte)) and emissions (i.e., CO, NO_x, HC, and PM) were exclusively summarized and discussed. Furthermore, various strategies used for adding water like water-diesel emulsion, direct water injection, and adding water into the inlet manifold were illustrated and their pros and cons were completely scrutinized. Finally, opportunities and limitations of each additive considering both engine performance and combustion benignity were outlined to guide future research and development in the domain.     

Axisymmetric FEA of temperature in a pad/disc brake system at temperature-dependent coefficients of friction and wear

Robust braking results in heat generation whose effects may have considerable impact on the parameters of the process such as wear rate and coefficient of friction. Fluctuations of the latter disagree with essential operational and braking requirements. Finite element analysis (FEA) of a single braking process for axisymmetric heat conduction problem of friction in a pad/disc brake system in the present article was carried out. Two materials of the pad FC-16L (retinax A) and FMC-11 (metal ceramic) and one material of the disc ChNMKh (cast iron) were analysed. Experimental dependencies of the coefficient of friction and wear rate on the temperature under specified contact pressures for these two friction pairs were approximated and applied to FE contact model. The temperature and wear evolutions on the contact surface of the pad/disc brake system obtained for constant and temperature-dependent abovementioned coefficients were confronted and compared. Mutual correlations of the obtained results with the studied materials were discussed.     

新型机车电空制动机试验研究

介绍了新一代微机控制的机车制动控制系统的形式和特点,并根据新型机车制动机方案,在实验室完成了列车编组定置试验。试验结果表明系统性能达到了设计要求。     

稀燃及废气再循环提高增压汽油机热效率的对比研究

在一台直列4缸增压直喷汽油机上针对万有特性最低油耗工况点,进行了稀薄燃烧与废气再循环(exhaust gas recirculation,EGR)提高发动机热效率的对比试验研究。试验结果表明:稀薄燃烧及EGR均能有效降低发动机燃油消耗率,稀释率分别为33%和19%时,采用稀燃和EGR时的最高有效热效率绝对值分别增加2.8%和1.7%,其中稀燃的有效热效率达到了39.9%,稀燃实现更高热效率主要归因于较低的传热损失和未燃损失。从燃烧角度来看,稀燃及EGR稀释都延长了燃烧滞燃期及持续期,但同样稀释率下稀燃的滞燃期更短,稀燃更高的稀释极限实现了更低的传热损失;但EGR抑制爆震,提前燃烧相位,使采用EGR时的排气能量损失低于稀燃。从排放角度来看,稀燃及EGR在高稀释率下均显著降低NO_x排放,而受益于高氧气浓度,相同稀释率下稀燃的HC及CO排放均低于采用EGR时,从而使稀燃的未燃损失更低。     

Performance and emissions characteristics of a lean-burn marine natural gas engine with the addition of hydrogen-rich reformate

The exhaust gas-fuel reforming technique known as reformed exhaust gas recirculation (REGR) can generate on-board hydrogen-rich gas mixture (i.e., reformate) by catalytic reforming of the exhaust gas and fuel added into the reformer and then recirculate the reformate into the engine cylinder, which can realize the combination of hydrogen-rich lean combustion and exhaust gas recirculation. The REGR technique can be employed to achieve efficient and stable lean-burn combustion for the marine engine fueled with natural gas (i.e., marine NG engine) and it is considered as an effective way to meet the stringent ship emissions regulations. In the present study, an experimental investigation into the effects of reformate addition ratio (R_re) and excess air ratio (λ) on the combustion and emissions characteristics of a marine NG engine under various loads was conducted, and the potential of applying the REGR technique in a marine NG engine to achieve low emissions (i.e., International Maritime Organization Tier Ⅲ emissions legislations for international ships) was discussed. The results indicate that the addition of the hydrogen-rich reformate gases can extend lean-burn limit. For a given λ, the flame development duration and rapid combustion duration decrease with the increase of R_re, and the combustion efficiency is improved. The brake specific NO_x emissions first increase and then decrease with the increase of R_re due to the competition between the combustion phase and total heat release value. The brake specific THC emissions decline with the increase of R_re, while the reverse holds for the brake specific CO emissions, and the behavior tends to be obvious under large λ. It is demonstrated that the combination of REGR and the lean-burn combustion strategy can improve the trade-off relationship between the NO_x emissions and brake specific fuel consumption of the marine NG engine to meet the IMO Tier Ⅲ NO_x emissions legislations and maintain relatively low brake specific fuel consumption.     

柴油机燃用柴油/水煤浆混合燃料性能与排放研究

对柴油机燃用柴油/水煤浆混合燃料进行了试验研究,结果表明:与柴油相比,使用混合燃料后柴油机多数工况的有效热效率下降;燃料消耗率有所增加,但折算成当量柴油消耗率基本降低;NO_x排放明显下降,最低为原机的20%;CO和HC排放有所上升,但仍能满足排放标准。     

机车制动安全系统的研究与探讨

机车运行中制动系统本身出现故障不能正常工作时,往往会造成机破。以装用JZ-7型制动机的机车为例,探讨安装机车制动安全系统确保机车有效制动和安全运行。     

Prediction of performance,combustion and emission characteristics of diesel-thermal cracked cashew nut shell liquid blends using artificial neural network

This paper explores the use of artificial neural networks (ANN) to predict performance, combustion and emissions of a single cylinder, four stroke stationary, diesel engine operated by thermal cracked cashew nut shell liquid (TC-CNSL) as the biodiesel blended with diesel. The tests were performed at three different injection timings (21°, 23°, 25°CA bTDC) by changing the thickness of the advance shim. The ANN was used to predict eight different engine-output responses, namely brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), exhaust gas temperature (EGT), carbon monoxide (CO), oxide of nitrogen (NO _x ), hydrocarbon (HC), maximum pressure (P _max) and heat release rate (HRR). Four pertinent engine operating parameters, i.e., injection timing (IT), injection pressure (IP), blend percentage and pecentage load were used as the input parameters for this modeling work. The ANN results show that there is a good correlation between the ANN predicted values and the experimental values for various engine performances, combustion parameters and exhaust emission characteristics. The mean square error value (MSE) is 0.005621 and the regression value of R ² is 0.99316 for training, 0.98812 for validation, 0.9841 for testing while the overall value is 0.99173. Thus the developed ANN model is fairly powerful for predicting the performance, combustion and exhaust emissions of internal combustion engines.