交流杂散电流对埋地钢质管道阴极保护电位的影响

为了明确交流杂散电流干扰对油气管道阴极保护电位的影响，通过设计的2套实验装置和恒电流极化法，分别研究了受有效电流密度为30、100、250 A/m²的交流干扰，阴极保护电流密度分别为-0.17、-0.25、-0.62、-2.26 A/m²时(对应电位约为-0.75、-0.95、-1.1、-1.2 V)的X70钢油气管道阴极保护电位变化情况。结果表明，交流杂散电流干扰下，阴极保护电位一般会正向偏移，但在阴极保护电位较正时，也可能发生负向偏移。可见，存在交流杂散电流干扰时，油气管道阴极保护电位会发生变化，从而影响阴极保护效果。     

埋地天然气管道杂散电流检测与评价

文中研究了涪陵页岩气田某埋地管道杂散电流干扰,进行了土壤表面电位梯度测试、管地电位测试、交流电压测试、土壤电阻率测试、SCM杂散电流重点检测。结合相关标准对检测结果进行评价发现:该埋地天然气管道全线直流和交流干扰程度均为弱,不需要采取直流或交流干扰防护措施。     

聚焦电流法隧道超前探测有限元模拟分析

文章结合聚焦电流法隧道超前探测原理,采用有限单元异常电位法对聚焦电流法隧道超前探测的电场分布进行了计算分析,并通过数值模拟,探讨了不同地电条件下聚焦超前探测的异常特征。结果表明,该方法能直观、明显的反映出掌子面前方不良地质体的位置、形态,避免隧道内金属干扰物对探测结果的影响。     

新大线管道杂散电流干扰的分析与防护

以新大线输油管线杂散电流干扰腐蚀问题为研究对象,进行干扰调查,并现场测试管地电位、土壤电位梯度、土壤电阻率和管线的杂散电流等参数.测试结果分析充分说明干扰来源于与新大线管道近距离平行的大连快轨3号线列车的运行,其特点是双向动态干扰,没有固定的阴极区和阳极区.提出采取增加阴极保护装置和极性接地排流方式共同防护来抑制杂散电流干扰,并客观分析排流效果.分析表明排流效果良好.     

高压直流输电影响下管道防腐保护装置

针对高压直流输电对管道防腐的影响特性,文中采用新型的强排流式管道阴极保护装置,该装置采用开关元件、DC-DC技术以及单片机技术,将电网单相电压变换成直流输出,并结合反馈系统,自动保持输出的电压稳定于设定值,维持地下的参考电极与管线之间合理的电位梯度分布,产生最佳管线防腐效果。     

管道阴极保护数值模拟实验

为了验证数值模拟软件研究埋地管道阴极保护及其干扰相关规律的可行性和准确性,建立了室内土壤模拟溶液模型和室外埋地环道模型,开展阴极保护实验。其中,室内模型实验通过改变阳极位置获得了2组显著不同的电位分布,而室外环道模型通过电缆连接改变管道和接地系统的电连续性。采用数值模拟软件进行电位分布计算和验证,其结果与电位测量数据基本一致。进一步通过软件对室外环道接地极排负实验的3种施工方案进行了数值模拟计算,优选出最佳方案。     

油气管道在高pH值环境下的应力腐蚀开裂

利用Na2CO3+NaHCO3溶液来模拟高pH值土壤环境,研究了X70管线钢在高pH土壤溶液环境中的应力腐蚀开裂,其机理为阳极溶解,观察到其裂纹扩展方式为沿晶类型,在高pH溶液中,存在外加电位时才能激发X70钢的SCC.外加阴极极化电位时,随着外加电位的负移,X70钢的SCC敏感性增加;在阳极极化电位区,随外加电位正移,X70钢SCC敏感性迅速降低,研究结果对预防已运营和新建输气管道的外部应力腐蚀具有一定的借鉴作用.     

交流干扰下新的阴极保护准则Iac/Idc的研究

文中探讨了交流杂散电流干扰下埋地管线钢新的阴极保护电位准则,即交直流比准则。利用PS-268A电化学测试仪,采用恒电位极化法测量试样保护电流密度,从而说明不同交直流比情况下的阴极保护效果。结果表明:在-850～-1 000 mV直流保护电位范围内,当交直流比值为5的情况下,实验中得到的保护电流密度最小,小于其他比值情况下103个数量级。在此保护电位范围内交直流比为5的情况下,对交流干扰下的埋地管线阴极保护效果最佳。     

杂散电流测绘仪在埋地钢质管道杂散电流检测中的应用

研究了杂散电流干扰的检测方法及对其干扰程度的评价方法，通过对杂散电流干扰成因和特点的分析，选择杂散电流测绘仪（SCM）作为检测和评价的手段。杂散电流测绘仪是一种智能化的测量仪器，通过后处理软件对采集的数据进行分析就可以获得管线周围杂散电流波形图及干扰数据，对杂散电流的测量与分析有助于掌握管线附近杂散电流情况及制定腐蚀控制策略。该仪器已经在工程中得到了很好的应用，取得了良好的效果。     

埋地钢管外防腐层破损检测中的电位梯度法

简述了埋地钢质管道外防腐层破损检测中的电位梯度法（包括直流和交流电位梯度法）原理,着重阐述了几种实际应用仪器及现场可能遇到的相关问题分析,最后对该方法的优缺点作了分析,认为该方法是当前埋地钢管外防腐层破损检测技术中最精确高效的。     

埋地钢制管道基于SCM检测仪的杂散电流测试与评价

杂散电流能够对埋地钢制管道造成很大的危害和破坏,严重影响管道的安全运行.应用智能杂散电流检测仪( SCM)对埋地钢制管道上的杂散电流干扰进行测试,通过对检测结果分析发现,智能杂散电流检测仪功能齐全,能够沿管道路线检测管道上各种杂散干扰电流的大小和方向,排除不需要的干扰信号,确定干扰源类型和来源;能够准确判断管道上杂散电...     

浅埋长阳极地床接地电阻的测试误差分析

电流极引起的电场畸变和电位极位置与远方大地位置的差异,是三极直线布线法测量长阳极地床接地电阻的主要误差来源。在采用网孔分析法对测量原理进行分析的基础上,结合现场测试结果发现：随着电流极与阳极地床距离的增加,接地电阻测试曲线上开始出现平缓区;接地电阻测量值逐渐接近计算值,测试误差减小。在现场场地限制的条件下,缩短电流极与阳极地床的距离进行多组测试后,进行拟合分析也能够满足工程需要。     

Individual characteristics and stated preferences for alternative energy sources and propulsion technologies in vehicles: A discrete choice analysis for Germany

With respect to the German goal of a transition to a lead market for electromobility within a short time period, this paper empirically examines the preferences for alternative energy sources or propulsion technologies in vehicles and particularly for electric vehicles. The data stem from a stated preference discrete choice experiment with 598 potential German car buyers. In order to simulate a realistic future purchase situation, seven vehicle types were incorporated in each of the six choice sets, i.e. hybrid, gas, biofuel, hydrogen, and electric vehicles besides common gasoline and diesel vehicles. The econometric analysis with flexible multinomial probit models reveals that potential car buyers in Germany currently have a low stated preference for electric, hydrogen, and hybrid vehicles. While our paper also discusses the impact of common vehicle attributes such as purchase price or service station availability, it particularly considers the effect of socio-demographic and environmental awareness variables. The estimation results reveal that younger potential car buyers have a higher stated preference for hydrogen and electric vehicles, males have a higher stated choice of hydrogen vehicles, and environmentally aware potential car buyers have a higher stated preference for hydrogen and electric vehicles. These results suggest that common policy instruments such as the promotion of research and development, taxation, or subsidization in the field of electromobility could be supplemented by strategies to increase the social acceptance of alternative vehicle types that are directly oriented to these population groups. Methodologically, our study highlights the importance of the inclusion of taste persistence across the choice sets and a high number of random draws in the Geweke–Hajivassiliou–Keane simulator in the simulated maximum likelihood estimation of the multinomial probit models.     

交联聚合物驱体系地面系统防腐措施研究

河南油田下二门矿交联聚合物驱体系地面系统的腐蚀情况比较严重，通过一系列的挂片试验分析得知，导致腐蚀产生的主要原因为焊缝腐蚀及交联剂本身的酸性腐蚀。采取的防腐措施为在地面注入系统，对交联剂罐及DN50以上管线采用T09—17涂层进行内防腐；对DN50以下管线采用铝塑复合管或工程塑料(ABS)管等。     

Assessing the cost-optimal mileage of medium-duty electric vehicles with a numeric simulation approach

Electric freight vehicles have the potential to mitigate local urban road freight transport emissions, but their numbers are still insignificant. Logistics companies often consider electric vehicles as too costly compared to vehicles powered by combustion engines. Research within the body of the current literature suggests that increasing the driven mileage can enhance the competitiveness of electric freight vehicles. In this paper we develop a numeric simulation approach to analyze the cost-optimal balance between a high utilization of medium-duty electric vehicles – which often have low operational costs – and the common requirement that their batteries will need expensive replacements. Our work relies on empirical findings of the real-world energy consumption from a large German field test with medium-duty electric vehicles. Our results suggest that increasing the range to the technical maximum by intermediate (quick) charging and multi-shift usage is not the most cost-efficient strategy in every case. A low daily mileage is more cost-efficient at high energy prices or consumptions, relative to diesel prices or consumptions, or if the battery is not safeguarded by a long warranty. In practical applications our model may help companies to choose the most suitable electric vehicle for the application purpose or the optimal trip length from a given set of options. For policymakers, our analysis provides insights on the relevant parameters that may either reduce the cost gap at lower daily mileages, or increase the utilization of medium-duty electric vehicles, in order to abate the negative impact of urban road freight transport on the environment.     

The market acceptance of electric motorcycles in Taiwan experience through a stated preference analysis

The environmental and energy concerns of using motorcycles in urban areas have fostered the rapid development development of electric motorcycles (EMs) in Taiwan in recent years. EMs' zero-emission, low noise level and high energy efficiency features provide the promising potential to alleviate the severe environmental pollution problem caused by the existing gasoline motorcycles. This study summarizes the recent development of the EM. More specifically, this study aims to analyze the potential demand for EMs based on an interview survey using stated preference modeling approaches. Study results show that female motorists are the potential target market for EMs. Developmental and energy-use issues of EMs are also discussed in this study.     

Local environmental impact assessment as decision support for the introduction of electromobility in urban public transport systems

The urban transport sector offers a noteworthy potential for the reduction of national greenhouse gas emissions as well as local pollutant emissions such as nitrogen oxides and particulate matter if electric drive systems are increasingly used. Owing to the fact that electric busses are still in the development phase, higher investment costs have evolved for public transport providers. Hence, decision making about where to introduce electric bus lines is mainly characterized by economic as well as technological considerations. The integration of local or regional ecological aspects is often neglected. An interdisciplinary approach was applied to the bus network of an urban public transport provider. By combining spatial-analytical techniques and statistical methods, the local environmental relief potential of electric busses has been evaluated. The results show that due to their specific line characteristics and the frequency of service, two bus lines out of 28 are particularly suitable for the introduction of electromobility in Dresden, Germany. The presented scientific work contributes to the extension of environmental assessments and decision making tools by including the spatial dimension of environmental impacts. It increases the practical relevance, especially for management decisions of political and entrepreneurial stakeholders by providing a sensible decision basis for local or regional infrastructure projects.     

腈纶厂设备材料316L腐蚀形式及防护

在湿纺腈纶生产中,因设备的腐蚀而造成的各种生产事故时有发生。由于其介质NaSCN具有强腐蚀性,凡是接触NaSCN的设备、管线、阀门等,均需采用含钼不锈钢材料316或316L,即00Cr17Ni14Mo2不锈钢。虽然在设备的材质上采用了特殊不锈钢,但由于生产环境的影响,设备的制造工艺、安装维修等原因,腈纶设备的腐蚀仍然存在。文中主要研究了腈纶厂回收车间设备的腐蚀,确定造成腐蚀的原因,分析其腐蚀的机理,并提出相应的防腐方法。     

Mainstream consumers driving plug-in battery-electric and plug-in hybrid electric cars: A qualitative analysis of responses and evaluations

Plug-in electric vehicles can potentially emit substantially lower CO₂ emissions than internal combustion engine vehicles, and so have the potential to reduce transport emissions without curtailing personal car use. Assessing the potential uptake of these new categories of vehicles requires an understanding of likely consumer responses. Previous in-depth explorations of appraisals and evaluations of electric vehicles have tended to focus on ‘early adopters’, who may not represent mainstream consumers. This paper reports a qualitative analysis of responses to electric cars, based on semi-structured interviews conducted with 40 UK non-commercial drivers (20 males, 20 females; age 24-70 years) at the end of a seven-day period of using a battery electric car (20 participants) or a plug-in hybrid car (20 participants). Six core categories of response were identified: (1) cost minimisation; (2) vehicle confidence; (3) vehicle adaptation demands; (4) environmental beliefs; (5) impression management; and, underpinning all other categories, (6) the perception of electric cars generally as ‘work in progress’ products. Results highlight potential barriers to the uptake of current-generation (2010) plug-in electric cars by mainstream consumers. These include the prioritization of personal mobility needs over environmental benefits, concerns over the social desirability of electric vehicle use, and the expectation that rapid technological and infrastructural developments will make current models obsolete. Implications for the potential uptake of future electric vehicles are discussed.