Experimental study on filtration and continuous regeneration of a particulate filter system for heavy-duty diesel engines

This study investigated the filtration and continuous regeneration of a particulate filter system on an engine test bench, consisting of a diesel oxidation catalyst（DOC） and a catalyzed diesel particulate filter（CDPF）. Both the DOC and the CDPF led to a high conversion of NO to NO2 for continuous regeneration. The filtration efficiency on solid particle number（SPN） was close to100%. The post-CDPF particles were mainly in accumulation mode. The downstream SPN was sensitively influenced by the variation of the soot loading. This phenomenon provides a method for determining the balance point temperature by measuring the trend of SPN concentration.     

Carbonyl emissions from heavy-duty diesel vehicle exhaust in China and the contribution to ozone formation potential

Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaidehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles （58.4 Gg）. The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles.     

超声波处理含油污水的物性实验探究

利用超声波处理含工业废机油的污水,阐述了超声波对裂解含油污水中油分子的作用主要是超声波的空化作用。在空化作用产生空化泡后,在局部形成瞬间的高温高压并进而产生强烈冲击波使得泡体周围的油分子键断裂,形成自由基,而后随着超声波的机械效应在污水表面形成一层大分子薄油膜,达到裂解复杂油分子除油的作用。文章通过实验得到了超声波的作用时间、超声功率和频率(40 kHz和28 kHz)对污水作用后对污水粘度和裂解效果的影响。实验表明:在频率相同的情况下,随着功率的增加,污水的粘度下降不断加快,裂解效果先增加后降低,约在70 W左右出现最大值;而在相同功率时间下频率为40 kHz的超声波比28 kHz的超声波作用含油污水后对粘度和裂解效果的影响更大;随着超声时间的增加,污水的粘度和裂解效果将持续下降,但是存在临界值。     

电力施工工程的安全管理环节优化初探

电力工程的施工安全关系着施工人员的人身安全以及居民企业的用电安全,电力企业加强对电力安全的管理,可以确保电力能源能够及时有效地输送给居民和企业,保证企业良好健康地运行。当前我国的电力施工依然存在着一些安全问题,本文对此进行了简要的分析,并且提出了从管理环节上进行优化的一些建议,希望能够为我国电力企业提供一些帮助。     

海底油气管道泄漏的原因及防范

随着全球油气工业正在向海洋进军,人类钻井足迹从陆地延伸到海洋,茫茫大海中出现越来越多的油气钻井平台,犹如洒在蔚蓝海面的点点星光。海底蜿蜒曲折的油气管道,成为全球能源运输动脉的重要组成部分。与此同时,随着海底油气管道不断延伸变长,海底油气管道破裂泄漏的风险也悄然增加,成为海洋溢油事故的原因之一,防范海底油气管道的泄漏已成当务之急。与传统碰撞或触礁导致油轮泄漏、钻采平台操作失误或部件老化等原因引发的溢油事故相比,海底油气管道破裂在行为模式、影响范围、修复周期等方面都有明显不同,因此应对策略和预防措施也必须加以调整。     

工程项目“模块化”助推本质安全发展

介绍了模块化施工的概念、原则及主要做法,以实例证明录取模块化施工可大大降低安全风险,提高施工效率。     

浅析公路工程的节能与环保施工策略

公路工程在建设过程中常常因噪声污染、生态环境破坏、资源的浪费等问题而引发社会的关注。为此,下面结合工程实际对公路工程的节能与环保施工策略进行探索,并提出具体的解决方案。     

浅谈水利工程施工安全管理

安全管理是水利工程施工管理的重要内容,尤其遇到隧道开挖、爆破等施工时,更应将安全管理当作工作的重点来抓,以防止发生安全事故,造成人员伤亡,阻碍水利工程施工的如期进行。本文结合笔者多年水利工程施工安全管理经验,从水利工程施工准备以及施工过程两个方面提出施工安全管理有效措施,以提高水利工程施工安全系数,确保水利工程施工质量,促进我国水利工程建筑行业的稳步发展。     

盾构施工对不同刚度桩体影响的数值分析

针对苏州轻轨一号线盾构隧道的施工情况,采用三维有限元数值模型,研究了盾构施工对不同刚度桩体的影响.计算结果表明:当盾构施工时,不同刚度桩体均偏向隧道移动,在隧道轴线处的横向位移均为最大.桩身横向位移最大值、竖向位移随桩体刚度增大而变小,桩身轴力、弯矩则随桩体刚度增大而逐渐增大,桩身最大负弯矩均出现在隧道轴线位置处.在盾...     

秋季施工扬尘PM10自动监测仪参比方法比对测试

施工扬尘是一类重要的污染源.适用性检测是施工扬尘PM10自动监测仪使用的前提.参照《环境空气颗粒物(PM10和PM2.5)连续自动监测技术要求及检测方法》(HJ653-2013)和美国加州《法规403扬尘》,采用国内外9种光散射法和4种β射线法施工扬尘PM10监测仪,在秋季施工工地开展了参比方法比对测试.结果表明:有3...