页岩气压裂双弯头弯管冲蚀规律研究

为研究页岩气压裂双弯头弯管的冲蚀规律,基于液-固两相流模型和冲蚀理论建立双弯头弯管冲蚀模型,研究典型工况参数、双弯头弯管结构参数对双弯头弯管冲蚀速率的影响。研究表明:最大冲蚀速率发生在压裂液首先流经的第一个弯头外拱内壁后半部分,第二个弯头冲蚀区域前移且冲蚀区域增大;双弯头弯管的最大冲蚀速率,随压裂液流体速度、支撑剂颗粒体积分数的增加均增大,随着支撑剂颗粒粒径、双弯头弯管曲率半径的增大均减小;双弯头弯管上弯头与下弯头装配转角为20°~40°时,双弯头弯管的最大冲蚀速率较大。     

水平弯管盐泥流动磨损仿真分析

盐泥为工业制盐流程中卤水净化工艺后产物，盐泥随意排放不仅污染环境，也会对资源造成极大浪费，需对盐泥进行无害化资源化处理。盐泥为固液两相流流体，对盐泥的无害化资源化处理需要管路的输送，为了探究盐泥在弯管中流动时对管道的冲蚀磨损速率，利用Fluent仿真软件对其进行分析。选用RNG k-?湍流模型和DPM模型，盐泥对弯管的冲蚀模型和颗粒碰撞恢复模型采用E/CRC冲蚀磨损模型和Grant and Tabaoff壁面碰撞恢复函数，考虑液固两相之间的耦合，对盐泥在水平弯管中的流动进行研究。研究结果表明：盐泥对水平弯管弯头压力分布场呈现为外侧压力大、内侧压力小，而速度分布场则与压力场恰好相反。盐泥颗粒与弯管内壁发生首次碰撞的部位在弯头外侧的出口段，一些颗粒还会发生多次碰撞。弯管内壁存在冲蚀磨损弯，弯头外侧磨损速率显著大于弯头内侧，而且磨损最严重的部位发生在弯头出口20°附近。     

小弯曲半径弯管的对挤成形

锅炉的弯管大都在弯管机上采用冷弯或热弯成形。管件的弯曲半径越小，其变形程度越大。在管件弯曲变形的同时，还会伴随着截面畸变。由于弯头的极限变形程度和截面畸变的限制，弯头最小弯曲半径必须大于某一极限数值，一般相对弯曲半径大于25。即使采用热弯，并辅以各种防止截面畸变措施，其最小相对弯曲半径一般也不能小于1．5。要想获得更小的弯曲半径的弯头，采用单纯弯曲是不可能实现的。近年来，随着锅炉制造工艺的发展，研究开发了一种小弯曲半径弯头成形新工艺——小弯曲半径弯头对挤成形。一、对挤成形工艺小弯曲半径弯头对挤工艺为…     

基于SolidWorks的圆管弯头对水流的影响分析

文章对弯管轴线上水的流速进行数值计算,分析弯头曲率及半径对管内水流的影响。结果表瞻选用弯管,当首选小曲率渐弯管;折管的折角越小,为其设置大曲率半径弯头的必要性越大。     

无缝弯头缺陷的超声检测

本文介绍了无缝弯头缺陷的超声检测原理和操作方法。     

在弯管机上用组合模具弯制340°弯管

我厂在为北京化工四厂制造丁辛醇装置的设备中,有一台文丘里清洗器。这台设备是由日本宇部兴产株式会社以反承包的形式,要我厂按ASME标准制造生产的。在这台设备中有一个关键部件是圆管分配器,此分配器要弯制的角度为340°(以下简称340°弯管)。弯管中心圆直径φ800mm,管子规格φ108mm×6mm,材料为SA312GrTP304L,见图1。按日方提供的     

气力输送中弯管磨损的影响因素及解决办法

概述了气力输送中弯管磨损的机理,详细阐述了气力输送过程中物料的物性、输送气速、料气比、弯管的结构及形状等主要因素对弯管磨损的影响。重点分析了输送气速的影响,并从弯管材料和结构2方面论述了减少弯管磨损的办法,建议用短半径和一端不通T型弯头代替长半径弯头。     

基于SolidWorks的圆管弯头对水流影响的优化

对圆管弯头的局部阻力进行数值计算,分析弯头曲率及曲率半径对水流的影响。结果表明：选用弯管应优先考虑小曲率、大曲率半径的渐弯管。     

高频设备冷却系统的改进

我们厂使用的高频设备为GP_1-100-C_1型,这几年我们对它的电子管冷却系统进行了一些小改进,从而有效地保证了电子管的运行安全,便于维修,现介绍如下: 一、原设备电子管冷却系统进出水回路中都接有三根玻璃管,两端使用铜管弯头,再用橡皮管把它们连接起来(见图1),以加强对地绝缘强度,减小体积。进出水管路中共有十六个接头,接口多,接口处最容易漏水和结水垢堵塞水路,     

W1001型履带起重机叶片泵联接方式的改进

W1001型履带起重机(以下简称履带吊)是在工矿企业、物资仓库中装卸货物广泛使用的一种起重设备。目前仍有许多单位在使用这些设备。我公司仍在用的有辽宁抚顺挖掘机厂、上海建筑机械厂、四川长江挖掘机厂生产的履带吊,这些设备均为20世纪60、70年代生产的设备,其构造和性能基本上相同。通过对这些设备的多年使用,发现设备上存在着一定的缺陷,这些缺陷的存在,往往容易发生故障,影响了设备正常运行和生产的进行。1故障与问题W100l型履带吊的液压工作系统中,系统的油压由1台叶片泵提供,叶片泵的运转状况决定着整个液压系统的工作压力。因此,确…     

立身文化及立身教育

“立身”作为传统文化概念,与“立德、立功、立言”之“三不朽”有同等重要的意义。甚至更具基础性。人生在世,何以立身,以何立身,这是自古至今人们都要思考并践行的。从文化传统视角考察,立身在人们的观念和行为中实际上是对道的遵从、对德的坚守、对礼的维护、对孝的体认。“遵道”具有天人合一的意蕴,“守德”强调主体良心的发现,“从礼”注重社会规则的价值,“讲孝”旨在强化事父忠君的家庭--社会模式的同构。立身文化的积极意义在于促进人的社会化、维护社会的和谐稳定。而立身教育就是要从文化的角度解决人何所由何所之、人的善良本性如何激发、人的规则意识怎样建立、人的品性如何养成的问题。从根本上说,解决立身问题是中国传统文化传承和发展的一条重要轨迹。     

高速铁路桥梁栏杆的机械化生产

根据我国武汉-广州铁路客运专线试验段工程施工的需要,对高速铁路桥梁栏杆机械化生产工艺和生产线进行了研究。通过相关生产工艺性试验,对目前国内普遍采用的混凝土产品生产基本工艺进行了指标检测和数据对比分析,创新性地提出了串联双效生产工艺,即预制件在浇注中先进行预振实,保证成品的密实度,离心成型时改善预制件的外观质量。同时结合工程施工实际,自行研制出了一条高速铁路桥梁栏杆机械化生产线,并介绍了机械化生产线的主要装置,其中包括隔柱、立柱、扶手生产线,主要设备包括离心成型机、振实台、模具拆装机具等,以及保障产品质量的生产过程控制。通过实践运用,高速铁路桥梁栏杆机械化生产线具有生产效率高、简单易操作,可靠稳定、维护费用低等优点。该生产线所生产的产品能满足栏杆结构受力与使用功能,具有外形美观、质量稳定可靠的特点。     

A review of issues surrounding the evaluation of industrial hypermedia applications

Over the past 30 years, companies wishing to improve their performance have progressively introduced computers in their work place and this has led to the appearance of computers on manufacturing shop floors. As part of their duties, shop-floor employees are now asked to use computer applications, in particular industrial hypermedia applications (IHA) containing task-related information (set-up, assembly, maintenance, testing, and quality procedures) to support task completion and/or training activities. If accepted and used, an IHA offers many benefits to both the company and the operators. Thus, logically an IHA should be evaluated to check the extent to which it is used or will be used. Although knowing the extent of acceptance is useful, the evaluation should also explain why it is so in order to enable developers to concentrate their efforts on key characteristics influencing user acceptance. To identify the key characteristics, this paper reviews the literature on the development and evaluation of IHAs. The objective is to summarise and organise those key characteristics within a framework and point out that the degree of appreciation of some of the characteristics are influenced by user differences. This framework provides developers with a frame of reference to evaluate whether an IHA meets most users’ expectations, to correct its shortcomings, and to build a body of knowledge around the development of well-designed IHAs. Before employing the proposed framework to evaluate an IHA prior and after implementation, it is essential to find reliable and valid instruments to measure two of the four characteristics and conduct empirical tests. This work is currently underway.     

An Assessment Framework for Optimal FMS Effectiveness

Equipment failures in an FMS are significant to performance and can lead to costly, incorrect decisions. Fortunately, effectiveness measurement techniques can be mapped to clever modeling frameworks to help predict, track, and then improve upon the FMS performability or mission effectiveness, and improve maintenance. This article provides sources and guidelines for efficient and effective FMS modeling, a framework for applying the modeling to predict the impact on customers from their point of view, and a method for tying it all together for improving the FMS effectiveness. It is not enough to simply examine the working and failed states of an FMS or even to calculate common reliability metrics. It is necessary to consider the FMS as a whole, and that system includes the needs of the customer and the business. It is also necessary to be purposeful about the measures of performance selected and to support the measures of effectiveness.In this article, we present: a framework for considering customer needs in the measures of effectiveness for FMS; modeling approaches for solving for effectiveness measures; and an example to show how to apply it to an FMS, to improve it or plan for meeting specific customer needs.     

建立油气管道设备失效率数据库的技术探讨

随着现代管道技术的突飞猛进,与过去相比站场设施的可靠性已经得到了极大改善,但是可靠性较差的设备仍会造成管线停产和产生过高的维修费用,所以清晰地认识设备失效事件的本质原因,对合理预测、安排和实施维修活动都具有关键的意义.通过建立油气管道设备失效率数据库,可以合理的预测、安排和实施维修和维护活动,同时对站场整体可靠性产生持续性的改进,更有效的改善安全性和经济效益.通过对失效率数据的分析可以产生广泛的收益,如：可以优化安排设备检修和大修时间、维护保养项目;除此之外,还可以在较大范围内对设备全生命周期中的备品备件和升级计划进行优化制定.     

飞机整体框类结构件铣削加工的模拟研究

针对航空整体结构件铣削加工变形的复杂制造问题，建立了三维铣削加工有限元模型。深入研究了材料模型、残余应力施加、动态切削载荷、材料去除等铣削加工模拟所涉及的关键技术．并详细论述了铣削加工模拟过程。应用该模型对某框类结构件进行了不同铣削顺序的加工模拟，通过零件变形模拟值与实验加工所得零件变形值的比较，证明该有限元模型可以实现对零件铣削加工变形规律的预测。     

Performance evaluation of introducing QS-9000 to the Taiwanese semiconductor industry

According to the survey conducted by AIAG in 1999, significant effects of QS-9000 certification included average cost savings of over 6%, a 38% improvement in defect rate and a 23% increase in market share on OEM. However, few manufacturers in semiconductor related industries in Taiwan have been QS-9000 certified to date. The major reason is there is not a complete and efficient set of implementation procedures for introducing QS-9000 and the certifying process. Consequently, methods of performance evaluation based on multiple goals and principles must be applied to assess the performance of the process of introducing QS-9000 to the Taiwanese semiconductor industry. First, the performance index and the performance matrix presented by Hung, Huang, and Chen are applied to assess the certifying importance and ease of implementation of each directive item (goal). Next, related correlation and weighted values among directives (objectives to be improved) of low importance and high easiness, and also of high importance and low easiness, are established using fuzzy measures. Finally, the directives to be improved (goals to be improved) are transformed to an overall performance value during the implementation process (strategy) by fuzzy integrals to define the critical implementation process (strategy) when QS-9000 is introduced to the semiconductor industry, and also to increase the timeliness of system introduction and certification. Management is expected to find the objectives and strategies to be improved related to the introduction of the QS-9000 system, and to certify this process through the complete assessment model presented here. Subsequently, the performance of introducing QS-9000 and certification may be increased after taking into consideration cost and time factors .     

基于web技术B/C结构下的英语自学系统设计与实现研究

随着科学技术的快速发展与进步,当今社会要求学生学习知识水平越来越高,要求其学习范围更为广泛.因此目前学生仅依凭英语课堂学习还远远不够,很多时候根本无法适应社会发展的需要,所以培养学生自学能力就显得非常重要.由此提出开发一款英语自学系统为英语爱好者提供自学英语平台.文章立足于Web网络,依托B/C结构,应用ASP.NET...     

无线射频识别(RFID)技术及其应用探讨

无线射频识别技术适合于实现系统的自动化,一套完整的RFID系统是由阅读器(Reader)、应答器及应用软件系统三个部分组成。当前RFID应用和发展面临着几个关键问题是标准、成本、技术和安全。在RFID应用中要注意选型要符合国家标准,要适合应用环境,还要与现有系统的结合等方面。     

新型换热器管子管板焊接工艺的研究

管板堆焊镍基合金，换热管为铁素体钢管，管子管板接头为平齐式的换热器是一种新型结构的换热器。管子管板角焊缝的焊接采用A-GTAW焊接方法。通过实验发现，为了得到质量稳定、焊缝尺寸和形状能够满足设计和相关技术条件要求的焊接接头，在严格限制镍基合金和换热管杂质元素含量、合理选择焊接工艺参数、控制焊枪钨极与管壁相对位置的同时，应采取以下两方面工艺措施：一是焊前对待焊区进行严格的清理，去除油、锈等杂质污物；二是在焊接过程中对管板进行低温预热。