自准直仪法测量柴油机机体主轴承座孔同轴度

本文介绍了用自准直仪法测量柴油机机体主轴承座孔同轴度的方法,此方法适用于大型孔系零件的同轴度测量,测量方便快捷,准确度高。     

自准直仪法测量柴油机机体主轴承座孔同轴度

本文介绍了用自准直仪法测量柴油机机体主轴承座孔同轴度的方法,此方法适用于大型孔系零件的同轴度测量,测量方便快捷,准确度高。     

测量多孔同轴度时孔径变化的影响与分析

分析在多孔同轴度测量中，孔径变化对测量结果的影响，并根据数学模型推导出了准确的计算公式，用计算公式得出的数值来对同轴度误差进行修正，可以消除孔径变化对同轴度误差测量结果的影响。     

石化容器同轴度和垂直度测量方法及不确定度评定

在石化容器生产制造领域,容器的同轴度和垂直度检测至关重要。利用工业三坐标测量系统来对石化容器的同轴度和垂直度等几何尺寸进行测量和控制。制定了石化容器的同轴度和垂直度测量方法并进行了不确定度评定,通过对不确定度评定进行分析,为明确此测量方法满足测量规范要求提供依据。     

水下管卡子安装同轴度调整的方法

叙述了常规水下卡子安装过程中同轴度调整的方法,提出,一种新的水下卡子同轴调整的方法,安装过程中使用带有收紧器的测量钢丝调整水下管卡子同轴度,可极大的提高作业效率,为水下管卡子安装工程提供借鉴。     

气门导管同轴度对气门油封泄漏率影响研究

随着发动机排放升级和寿命提升,对气门油封安装后整机运行实际机油泄漏率一致性要求进一步提高.通过测量不同气门导管同轴度时的气门油封的机油泄漏率,研究了气门导管同轴度对气门油封机油泄漏率的影响.试验结果表明:气门导管同轴度对气门油封机油泄漏率的影响较大,且非线性关系,存在失效临界点Φ0.3 mm.通过加工定位优化,可以确保尺寸一致性,进而保证机油泄漏率性能一致性.     

用光学自准直仪测量柴油机机体主轴承孔同轴度

介绍用光学自准直仪测量主轴承孔同轴度的步骤与方法。实践证明：光学自准直仪适用于生产现场对大型零件孔同轴度的快速、准确测量,且其不受被测孔径表面质量的影响。     

气门盘锥面对气门杆部同轴度的测量方法

0引言 气门盘锥面的形位误差和表面粗糙度决定气门密封效果,通常气门盘锥面部位的形位误差图纸上只要求测量圆度和跳动误差。目前国外有公司要求我厂为其生产的气门必须控制气门盘锥面对杆部的同轴度,且检测手段是圆柱度仪。但是我厂圆柱度仪上测量项目只有圆度、圆柱度、平度、直线度。如何测量同轴度误差？本人经过反复实验在TR265泰勒圆柱度仪上检测出气门盘锥面对杆部的同轴度误差。并且检测数据得到了认可。     

一种甲醇合成塔上、下中心接管同轴度检测方法

本文介绍了一种甲醇合成塔上、下中心接管同轴度的检测方法,主要利用两台激光跟踪仪进行组合测量,分别测量上、下封头中心接管相关尺寸数据,然后将建立相应的直角坐标系,指导车间对其进行调整,从而保证上、下封头中心接管同轴度满足技术要求。     

视频显微法在联轴器同轴度调整中的应用

在水泵或水轮发电机等机械设备的安装与检修中,联轴器同轴度的检测调整是一道细致而又费时的工序,该道工序的质量直接影响机械设备之间动力传递的质量和效率。针对传统同轴度检测装置存在狭窄空间难以安装、人员识读数据困难等缺点,研制了一种新的测量装置视频显微法,该装置采用电子显微镜、手持终端及无线传输、显微测量、数字计算等新技术和设备。实例应用结果表明,该装置方便、高效,易于在联轴器类机械的同轴度检测与调整中推广应用,可显著提高设备安装与检修工作质量与效率。     

二维水动力模型在姚江大厍船闸通航影响分析中的应用

为分析引排水工程对船闸通航的影响,以大厍船闸为例,在"姚江西排"工程的背景下,利用MIKE 21软件构建了二维水动力模型,设计了11个引水工况和2个排水工况,计算了各工况下的水动力条件及河道冲淤情况。计算结果表明,各引水工况下,船闸引航道处水流纵向流速均在0.01～0.02m/s,横向流速均小于0.01m/s,且无冲淤发生;排水工况下,船闸引航道处水流纵向流速在0.12m/s以下,横向流速小于0.09m/s,在河道内有局部轻微冲淤;综合评价引排水工程对大厍船闸的通航无明显影响。研究成果可为类似船闸通航影响分析提供参考。     

贾汪 PFBC_CC 中试电站异形煤仓设计和试验

借助詹尼克整体流动斗仓设计方法对实际斗仓中的几个特殊问题进行分析和简化处理,研究了在一个异形粒煤斗仓内产生整体流的取形问题,并通过模型试验验证了某结果的正确性。,     

Biomass granular screw feeding: An experimental investigation

Successful feeding is critical to biomass utilization processes, but difficult due to the heterogeneity, physical properties and moisture content of the particles. The objectives of the present study were to find the mechanisms of blockage in screw feeding and to determine the effects of particle mean size (0.5-15 mm), size distribution, shape, moisture content (10-60%), density and compressibility on biomass particle feeding at room temperature. Wood pellets, sawdust, hog fuel and wood shavings were tested in a screw feeder/lock hopper system previously employed to feed sawdust into a pilot-scale circulating fluidized-bed gasifier. Experimental results showed that large particles, wide size distributions, large bulk densities and high moisture contents generally led to larger torque requirements for screw feeding. The “choke section” and seal plug play important roles in determining the torque requirements.     

Response of shielding structures to explosive loading

This paper presents the results of a numerical and experimental study of the behaviour of a brass hopper held in a supporting structure subjected to internal explosive loading. The structure is typical of those employed during the manufacture of explosive accessories. In such processes the hopper acts as a feed for the explosive while the encasing structure both supports the hopper and provides protection to the surroundings in the event of accidental initiation. The finite element model includes representations of the explosive, the brass hopper and the steel supporting structure. The boundaries between the components are treated as sliding and separable interfaces. Analysis is performed using the Oasys DYNA3D (version 5.1) finite element program. The numerical predictions for the deformations are compared with test results. The DYNA3D finite element code is shown to be an effective tool for the appriasal of this type of protective structure under explosive loading. Both the numerical and experimental studies point the way to improvements in the current design.     

壳牌气化炉开工烧嘴点火故障分析及预防措施

壳牌煤气化技术是目前世界上最先进的煤气化技术之一,我国自1997年来已陆续引进23台壳牌气化炉,单台气化炉日投煤能力为1000t或2000t,产品合成气大部分用于生产合成氨、甲醇和氢气,目前有10套以上装置已经开车。从已投产的气化炉运行情况看,壳牌气化炉的设计理念非常先进,但存在的问题也很突出,主要是运行稳定性差,故障率高,例如:锁斗开关阀卡死、大渣块容易堵管、开工烧嘴易烧坏、粉煤输送不稳定、激冷器压缩机和飞灰陶瓷过滤器故障频繁等,这主要是壳牌炉设计上的先天不足导致的。壳牌气化炉开车时设置了三级点火,相应配置了点火烧嘴、开工烧嘴和粉煤烧嘴,其中开工烧嘴由于其设计的特殊性,致使其点火难度大,故障率高。从介绍其结构和原理入手,着重分析了开工烧嘴的几个典型故障案例,深入剖析了原因。建议国内壳牌炉用户加强相互间的交流,总结经验,从开工烧嘴安装开始直到投产运行,各阶段都能积极采取有针对性的预防措施,少走弯路,尽量降低开工烧嘴点火的故障率,同时建议国内壳牌炉用户积极配合国内相关企业做好开工烧嘴的自主创新工作,尽快实现开工烧嘴的国产化,降低设备成本,打破外商的垄断。     

料仓内稠密粉体卸料流动特性研究

为了研究料仓内粉体卸料流动及混合特性,采用实验与模拟相结合的方法,利用粉体的溶解性质获得两种粉体卸料过程的混合曲线,并建立能够进行大规模数值计算颗粒间固相作用力的三维数学模型。该模型基于欧拉与拉格朗日相结合的方法,利用相邻网格间固相颗粒浓度梯度与颗粒平均速度梯度来描述颗粒间的固相作用力。结果表明:料仓半顶角与卸料口径对粉体卸料流率的影响的模拟结果与实验结果及Brown经验关联式预测值吻合较好。两种粉体卸料过程的混合指数随料仓半顶角的增加而减小,减小卸料口径时混合指数有所减小但减幅不大,表明增加料仓半顶角以及减小卸料口径均会促进两种粉体在卸料过程的混合。     

基于光伏发电供电的指纹锁的设计

以光伏发电与指纹锁为研究基础,通过实验研究将两者进行结合,然后制作样品并利用仿真使用环境对基于光伏发电供电的指纹锁这一设计的可行性与稳定性进行了论证.结果表明:这类具有光伏发电供电功能与指纹识别功能的密码锁的稳定性良好,在移动设备上或在可接收到太阳光直射的场合使用,能够减少对供电设备的需求,使用更加便捷.     

湛江电厂4~#炉严重结焦的原因分析及防止措施

分析湛江电厂4#锅炉因频繁发生结焦而引起水冷壁渣斗严重堵渣的原因,并提出了解决措施:优化配煤,减少卫燃带面积,矫正切圆偏离,加强吹灰。     

The effects of physical and chemical preprocessing on the flowability of corn stover

Continuous and reliable feeding of biomass is essential for successful biofuel production. However, the challenges associated with biomass solids handling are commonly overlooked. In this study, we examine the effects of preprocessing (particle size reduction, moisture content, chemical additives, etc.) on the flow properties of corn stover. Compressibility, flow properties (interparticle friction, cohesion, unconfined yield stress, etc.), and wall friction were examined for five corn stover samples: ground, milled (dry and wet), acid impregnated, and deacetylated. The ground corn stover was found to be the least compressible and most flowable material. The water and acid impregnated stovers had similar compressibilities. Yet, the wet corn stover was less flowable than the acid impregnated sample, which displayed a flow index equivalent to the dry, milled corn stover. The deacetylated stover, on the other hand, was the most compressible and least flowable examined material. However, all of the tested stover samples had internal friction angles >30°, which could present additional feeding and handling challenges. All of the “wetted” materials (water, acid, and deacetylated) displayed reduced flowabilities (excluding the acid impregnated sample), and enhanced compressibilities and wall friction angles, indicating the potential for added handling issues; which was corroborated via theoretical hopper design calculations. All of the “wetted” corn stovers require larger theoretical hopper outlet diameters and steeper hopper walls than the examined “dry” stovers.     

一种基于NFC的无源智能锁及其在配电网中的应用

针对配网柜体采用的传统机械锁具管理难度大、破解容易以及可追踪性差,无法满足现代电网快速发展的多样化需求等问题。该文研制了一种基于配电物联网架构的无源高可靠性智能电子锁。其内嵌安全芯片,采用近场通信(Near Field Communication,NFC)技术完成通信及取能,无需机械钥匙开锁,无需维护更换锁具电池,并配套开发了能够实时监测锁具状态、储存开锁信息的智能锁管理系统以及配合开锁APP使用的电子钥匙,分析了智能锁具的硬件设计及系统的应用流程。最后,通过实践应用表明,该套锁具系统在运维便捷、信息安全和科学管理方面具有明显效用。