海宝HT2000等离子切割机弧转移的故障排除

海宝HT2000等离子切割机是一款高速、高精度的金属切割设备。文章从维修实践出发,简单阐述了等离子切割的原理及海宝HT2000等离子切割机的工作时序,着重介绍了割炬中存在高频但无引导弧故障可能的原因及解决此类故障的方法,并逐步排查从而彻底解决了此故障。     

柴油汽车SCR技术的应用研究

分析国内厂家采用SCR技术满足欧Ⅳ排放的原因,介绍SCR系统的组成和工作原理、柴油汽车SCR系统的应用方案,研究影响SCR系统NOX转化效率的主要因素。     

圆形料场储量分析及计算

大型全封闭圆形料场以其技术先进、自动化水平高、环保性能突出、损耗低等特点,已被广泛应用于电力、钢铁、焦化、港口、矿山、粮食等行业的散性物料的存储和输送系统。储量作为圆形料场的最重要的指标参数之一,备受使用者的关注。对于圆形料场储量的计算,目前还没有现成的计算公式。通过对料堆几何模型进行分析,结合多年的设计经验,对圆形料场储量计算方法进行了分析、总结,以方便使用者根据各自条件进行选用。     

BFM2012型柴油机曲轴箱通风系统油气分离器改进

为了改善油气分离效率,降低机油携出量,并维持合理的曲轴箱压力,以BFM2012型柴油机为研究对象,提出了在发动机预分离之后连接一个弥散式油气分离器的新方案,并将新油气分离器与原离心式油气分离器做了对比试验研究.试验结果表明,配备弥散式油气分离器后,活塞漏气量下降1～3 L/min,曲轴箱压力升高40Pa,油气分离效率由原来的53％提高到79％～95％,且不影响加机油的周期,但曲轴箱通风系统阻力增加较明显.     

Phenomenological two-phase multi-zone combustion model for direct-injection diesel engines

This paper proposed a quasi-dimensional combustion model from a new observed two-phase penetration and combustion phenomenon in diesel spray. In the model, fuel spray was divided into two of liquid and gas phase areas. Considering the phenomenon that separation of gas and liquid phase in diesel spray occurs during spray penetration, gas and liquid area of spray are discretized respectively. Liquid phase areas play important role in fuel mass transport, however gas phase areas are the main region for fuel combustion in the model. Fuel and air mixing rate of gas phase zone is the key for the calculation of combustion rate. Validation experiments are designed by using optimal Latin hypercube design method. Comparison of calculations and experiments show that the model is able to predict diesel engine performance at different engine speeds, loads, and injection pressure and timing, and provides guidance for the design of engines.     

机车周转图的计算机优化算法

作者在分析机车周转图特点的基础上,将机车周转图的优化问题转化为典型的求图染色数法的数学问题,进而给出求最小机车台数机车周转图及机车交路的勾画方法。方法简单而有效。     

某重卡CAN总线控制系统的设计

CAN是一种有效支持分布式控制或实时控制的串行通信网络。本文以某重型卡车为例,遵守J1939协议,通过CAN网络拓扑架构的搭建,展示了车身控制系统的的工作过程和故障诊断过程,论述了CAN总线在商用车重卡领域的应用和CAN在电控系统中应用的经济性、方便性及准确性。通过CAN总线控制系统与传统线束控制对比,体现了CAN总线系统的强大优势。     

快递运输车油耗研究与动力配置优化

以快递运输车为研究对象,针对用户使用情况进行了调研和实车道路采集,解析出快递运输车典型用户行驶循环工况。基于所提取的循环工况进行了综合油耗仿真分析,并进行了客户试验验证。结果表明,仿真计算油耗与客户实际使用油耗一致,得出适合快递运输车的最佳动力配置。     

Containership structural design and optimization based on knowledge-based engineering and Gaussian process

Knowledge-based engineering （KBE） has made success in automobile and molding design industry, and it is introduced into the ship structural design in this paper. From the implementation of KBE, the deterministic design solutions for both rules design method （RDM） and interpolation design method （IDM） are generated. The corresponding finite element model is generated. Gaussian process （GP） is then employed to build the surrogate model for finite element analysis, in order to increase efficiency and maintain accuracy at the same time, and the multi-modal adaptive importance sampling method is adopted to calculate the corresponding structural reliability. An example is given to validate the proposed method. Finally, the reliabilities of the structures＇ strength caused by uncertainty lying in water corrosion, static and wave moments are calculated, and the ship structures are optimized to resist the water corrosion by multi-island genetic algorithm. Deterministic design results from the RDM and IDM are compared with each separate robust design result. The proposed method shows great efficiency and accuracy.     

基于工业现场的无线自组网设计与应用

从工业现场应用实际出发,以工业无线自组织网络高可靠、实时通信问题为研究对象,设计了一种更适合工业现场应用的轻量级无线自组织网络通信协议(TWRP),并通过仿真和现场运行数据验证了在提高通信可靠性、实时性方面具有有益效果。