基于走航巡测模式的长江重庆—武汉段水质调查与分析

采用走航巡测模式对2020年长江重庆—武汉段水质状况开展调查分析,并对192个巡测点位38项自动监测参数进行统计、评价、分析。结果表明：长江重庆—武汉段水质良好,全部达到或优于Ⅲ类水标准,各参数测定值水平整体不高;部分点位水质参数存在明显测定峰值,在一定程度上反映〖JP2〗周边水域受到潜在污染影响;城市江段、产业园区、港口码头、航运频繁水域污染物测定值相对增高,仍须将聚集性区域作为污染防控重点,〖JP〗加大减排力度,降低长江水污染潜在风险。     

强制分散活性炭处理焦化废水的实验研究

采用活性炭为吸附剂,强制分散和静态条件下处理焦化废水,对焦化废水中的主要污染物CODcr、氨氮、酚和氰化物的去除规律进行了细致的分析研究。考察了强制分散下活性炭不同粒径、投加量、曝气量对活性炭吸附焦化废水中污染物的影响并对其机理进行了分析。结果表明：强制分散条件下活性炭对焦化废水中污染物的去除具有显著的作用：同时活性炭的粒径越小,曝气量越大,效果越好,达到平衡的时间越短。     

工伤保险在社保制度中的排序变化及其内涵

目前我国常见的社会保险制度排序是养老保险、医疗保险、失业保险、工伤保险和生育保险,工伤保险制度位列第四位;而在计划经济时期的劳动保险制度系列中,工伤待遇规定曾位居第一位,尔后才是医疗待遇规定、养老待遇规定和生育待遇规定。上述排序变化的出现不会是立法者的偶然随意之为,而是以实行市场经济体制改革后我国劳动者-企业-国家之"三方关系"出现的根本性变化为背景原因的,与制度本身从一种面向牺牲了个人安全和健康的建设功臣们实施的国家慰谢待遇向以分散风险、损失共担为机理的保险制度发生的转化密切相关。针对近年来极端劳资纠纷事件增多的趋势,我国的劳动安全管理及工伤保险立法决策还应更加注重向弱势劳动者的倾斜。     

冶金行业安全生产标准发展现状与对策研究

首先分析了我国冶金行业安全生产标准发展现状和存在的主要问题,论述了冶金行业安全生产标准发展规划以及从纵向产业链生产诸单元和横向关键生产环节(工艺)安全生产标准所覆盖的较为完整的冶金行业安全生产标准体系。最后阐述了冶金行业安全生产标准发展对策。     

复杂地形对含硫气井应急计划区划分的影响

研究复杂地形对含硫气井应急计划区(EPZ)划分的影响,为高风险油气田的安全生产提供参考。根据含硫气井井口与周边地形的关系,将复杂地形分为3类;选择不同类型复杂地形的3口含硫气井,采用大涡模拟方法模拟不同H2S释放速率、不同风速和风向、不同井喷点火时间的组合条件下H2S大气扩散质量浓度场,积分计算各井H2S毒性负荷的时空分布。在此基础上,研究EPZ半径与H2S释放速率之间的关系,然后建立以H2S释放速率为指标的不同类型复杂地形含硫气井EPZ的划分方法。结果表明第一类模型计算结果明显大于第二类和第三类模型,第三类模型的计算结果最小,此差异随着H2S释放速率增大而愈显著。计算结果合理,方法适用且可行。     

海底管道腐蚀防护状态检测方法

目的 介绍一种海底管道腐蚀防护状态的非接触式检测方法 ,验证基于远地参比电极电位差测量的海底管道腐蚀防护状态检测方法 的可行性.方法 论述基于远地参比电极电位差测量的非接触式检测方法 的原理,并应用数值模拟软件模拟计算964.6 m长的海底管道的电位,分析5种不同工况下埋深海底管道的整体电位在200 m水深范围内的分布...     

机械制造企业安全现状模糊综合评价

为完善机械制造企业安全现状综合评价指标体系及评价方法,建立了包括人、物、环、管四个方面的机械制造企业安全现状综合评价指标体系,提出了模糊综合评价方法;运用层次分析法计算指标权重,采用专家评价和隶属度函数相结合的方法来确定各指标的评语等级隶属度;将该方法应用于湖南某汽车制造企业的安全现状综合评价中,得出企业安全现状等级为较好,明确了该企业在人员素质和作业环境方面存在的不足,为制定安全对策措施提供了指导。     

国内尾矿库物理模型试验研究现状分析*

为提高尾矿库物理试验的科学性与可靠性,采用文献资料收集与分析方法,对国内尾矿库物理模型试验的研究现状与主要成果进行梳理和归纳;总结试验模型存在的问题与不足。结果表明:溃坝机理试验主要研究了管涌渗透、洪水漫顶、地震作用下的溃坝及其演化过程;下游演进试验主要揭示了溃坝过程中泥深、冲击力、流速、泄砂量、淹没范围等时空分布规律;稳定性评价试验主要利用物理试验得到的浸润线位置、尾砂沉积分布等数据建立数值模型,对尾矿库筑坝过程、不同工程状况下的稳定性进行分析;防护试验主要对坝体加筋及拦挡坝防护效果等进行研究。从溃坝机理与过程、溃坝主要影响因素、溃坝下泄物运移过程、物理模型设计和构建、监测技术和手段等方面提出相应的研究建议,供研究学者参考借鉴。     

Accident consequence calculation of ammonia dispersion in factory area

With the widespread use of ammonia in the process industry, more and more accidents were caused by ammonia leakage and dispersion. The dispersion of ammonia is determined by its physical properties, release source conditions and atmospheric environment. Full-scale numerical simulation based on CFD theory was carried out to study the dispersion law of ammonia in a food factory. It was found that ammonia concentrated on the symmetric plane and showed an upward movement near the source. Moreover, the effect of pressure on the dispersion of ammonia was explored showing that the concentration of ammonia near the source increased with the increase of pressure, while the dispersion of ammonia far from the source is mainly influenced by wind field. Last but not the least, the dangerous area completely covers the obstacle region according to the harmful concentration, but the lethal concentration range and explosion range both only existed near the release source. Correspondingly, the concentration of ammonia in the region far from the symmetric plane can be regarded as a safe area. When the accident happens, one should stay away from the release source and evacuate towards the sides in a timely manner. We hope that this work can provide an effective method in predicting the impact of ammonia dispersion and can arouse concerns over the public safety.     

On the non-monotonic wind influence on flammable gas cloud from CFD simulations for hazardous area classification

Hazardous areas are defined as a result of a variety of variables as storage temperature, pressure, leak orifice size, physical properties of flammable substance, and wind characteristics. The potential formation of an explosive atmosphere must be accurately assessed to ensure process safety. Therefore, computational fluid dynamics (CFD) arises as an important tool for accurate predictions as recommended by the international standard IEC 60079-10-1 (2015). This study aims to analyze the influence of wind velocity magnitude and direction on the hazardous area classification. The authors evaluated the extent and volume for methane, propane, and hydrogen leakages from a CFD model. For each flammable gas, the wind velocity magnitude and direction were regularly varied. The outcomes show that the behavior of the plume size as the wind varies mainly depends on the gas concentration. Counter-flow wind directions lead to zero relative velocity closer to the release point, which concentrates the gas, and wind in the release direction promotes a higher dilution of the gas cloud increasing the hazardous extent while decreases the volume. As a consequence, the wind also influences the zone type, which was accurately predicted from CFD simulations and significant differences were found when compared to the standard analyses. These differences are, to some extent, related to the consideration of wind velocity effects on the gas jet release.