直喷式柴油机燃用脂肪酸甲酯的排放特性

脂肪酸甲酯是由生物脂肪经过酯化反应得到的脂肪酸单酯,具有良好的燃料品质和环境友好性,是生物柴油众多种类中的一种.以纯矿物柴油、脂肪酸甲酯、含30%脂肪酸甲酯与70%柴油的混合燃料和含50%脂肪酸甲酯与50%柴油的混合燃料为燃料,在四缸涡轮增压直喷式柴油机上进行的性能对比实验,表明柴油机燃用脂肪酸甲酯能够保持其动力性和燃料经济性,可以显著降低HC和碳烟排放,但会增加CO和NOx排放.脂肪酸甲酯可以作为柴油机的代用燃料进行推广.     

生物柴油:汽车燃料的革命

在美国,有越来越多的私人车辆以及政府部门和公司的车辆开始使用生物柴油。一些科学家认为,用“生物柴油”作燃料,也许可以闯出一条新路来。     

别再小瞧地沟油

在巴西的坎皮纳斯市，许多公交车上都喷上了“此车用生物柴油驱动”的字样．坎皮纳斯华人社团巴中联合会总干事宋天乐先生告诉我们，他们的工厂炼制的生物柴油，按一定比例与柴油配制成生物燃料，供当地的公交车使用，这些喷了字样的公交车就是用他们的生物燃料驱动的。     

节能:汽车竞争的焦点

节能将是未来汽车竞争的一个焦点。专家预测,2006年至2020年,我国汽车保有量将以每年8%的速度增长,到2020年,我国石油总需求量将接近5亿吨。为此,我国将大力推广天然气、液化石油气、生物柴油、甲醇、二甲醚、氢燃料等多种新     

柴油废气的危害

柴油燃料是一种复杂的石油化合物的混合物.燃烧时排至空气中的废气含有上千种的化学物质.主要成分为水、二氧化碳、氮气与碳粒(黑烟).     

甲醇储罐区火灾爆炸的危险性及消防设计探讨

正甲醇在现代化的生产生活中是一种重要的有机化工原料,应用广泛,其可以用来生产合成橡胶、对苯二甲酸二甲脂、甲胺、氯甲烷、甲基丙烯酸甲脂、醋酸、甲基叔丁基醚、甲醛等多种有机化工产品,而且还可以用来合成甲醇蛋白质。同时甲醇也是优质燃料,在进行深加工后可作为一种新型清洁燃料,甲醇掺烧汽油,在北美和西欧已合法化。     

浅谈液化石油气储配站的安全管理

液化石油气作为一种新型清洁燃料,由于其具有热值高、无烟尘、无炭渣,操作使用方便等优点,已广泛地进入人们的生活领域并愈来愈受到人们的重视。     

大力开发利用煤气层促进瓦斯产业发展

矿井瓦斯是矿井中主要由煤层气构成的以甲烷为主的有害气休,是在煤的生成和煤的变质过程中伴生的气体.瓦斯,又称为煤层气,其实是吸附在煤层中的一种非常规天然气,其主要成分和天然气一样,实际上是一种热值高、无污染的优质的新型清洁能源,可用于发电燃料、工业燃料、化工燃料和居民生活燃料.瓦斯事故是我国煤矿安全事故居高不下的主要矛盾,有效控制瓦斯事故是解决中国煤矿安全问题的关键.     

未来清洁动力车:燃料电池汽车

目前,一种很有市场前景的清洁动力汽车——燃料电池汽车,成为国际汽车巨头竞争的一个热点。燃料电池汽车利用氢与氧进行化学反应产生电,然后再以电能驱动;通过氢和氧化学反应生成水蒸气,不排放碳化氢、一氧化碳、氮化物和二氧化碳等污染物质,是21世纪最有前途的环保型汽车。     

能源新方向 害草变燃料

我国科学家开展的一项研究发现,被列为世界十大害草之一的水葫芦,可在微波联合碱作用下实现能源化利用,制取燃料酒精、氢气、甲烷等清洁燃料。浙江大学能源清洁利用国家重点实验室的课题组研究了微波联合碱对水葫芦降解和糖化的影响规律,包括微波加热时间、功率以及碱用量等。     

UiO-66-(COOH)2对水溶液中In(Ⅲ)的吸附性能

以水作溶剂,采用简单的回流法合成了一种稳定的金属有机骨架材料UiO-66-(COOH)2,并首次将其用于In(Ⅲ)离子的吸附分离。采用傅里叶变换红外光谱(FTIR)、热重分析(TGA)、N2吸附-脱附和X射线衍射(XRD)等手段对材料进行了表征。通过静态吸附试验,探讨了pH值、接触时间和溶液初始质量浓度等因素对材料吸附In(Ⅲ)离子性能的影响。结果表明,在pH值为3.0、温度为303 K的条件下,UiO-66-(COOH)2对In(Ⅲ)的最大饱和吸附容量可达84.29 mg/g,优于大多数文献的报道值;整个吸附过程在90 min左右完成,且符合Langmuir等温吸附方程,而吸附动力学可以用准二级动力学模型进行描述。其可能的吸附机理是UiO-66-(COOH)2中的羧基与In(Ⅲ)离子的配位作用。此外,该材料能够实现重复使用,且在Na(Ⅰ)、K(Ⅰ)、Mg(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)和Ni(Ⅱ)等竞争性金属离子的存在下,对In(Ⅲ)仍具备较好的吸附选择性。研究结果为含铟废水的处理提供了一种有效的新途径,也进一步拓展了MOFs材料的实际应用。     

安全管理学及其具体教学内容的构建

通过对安全管理实务和安全管理活动的理论分析,首先,把安全管理学广义地定义为关于事故预防的科学,并分析得到其详细内容、逻辑结构和应用原理;然后,将安全管理学狭义地定义为与安全相关的关于行为协调的科学,并选择性地构建其具体的、与其他课程没有或较少交叉的具体教学内容。     

Maintaining the corporate memory

A well known fact is that corporations don’t have memories. This is because the majority of the knowledge is maintained in the employees’ heads and when they leave that knowledge walks out with them. This continues to be the bane of process safety as errors get perpetuated and incidents repeated. A system can be created, though, to form and keep a corporate memory by accumulating the knowledge as it is developed and saving it in an organized manner, to be easily found and used by others as needed. In a previous paper we saw how knowledge can be organized. In this paper we will show that knowledge is best shared by example (for instance, we would like to design our plant based on the best applicable designs available), and how it can be continually collected with little effort once a proper workflow has been adopted. In this workflow the knowledge is reviewed and indexed as part of the collection process and organized into the niches of a previously created framework. The resulting knowledge infrastructure serves as the corporate memory and besides being a boon to process safety, it becomes an efficiency machine (no more need to reinvent the wheel!).     

Modeling quenching distance and flame propagation speed through an iron dust cloud with spatially random distribution of particles

In this research combustion of iron dust particles in a medium with spatially discrete sources distributed in a random way has been studied using a numerical approach. A new thermal model is generated to estimate flame propagation speed and quenching distance in a quiescent reaction medium. The flame propagation speed is studied as a function of iron dust concentration and particle diameter. The predicted propagation speeds as a function of these parameters are shown to agree well with experimental measurements. In addition, the minimum ignition energy has also been investigated as a function of equivalence ratio and particle diameter. The quenching distance has been studied as a function of particle diameter and validated by the experiment. Considering random distribution of particles, the obtained results provide more realistic and reasonable predictions of the combustion physics compared to the results of the uniform distribution of particles.     

A multivariable model for estimation of vapor cloud explosion occurrence possibility based on a Fuzzy logic approach for flammable materials

In this paper, a new method based on Fuzzy theory is presented to estimate the occurrence possibility of vapor cloud explosion (VCE) of flammable materials. This new method helps the analyst to overcome some uncertainties associated with estimating VCE possibility with the Event Tree (ET) technique. In this multi-variable model, the physical properties of the released material and the characteristics of the surrounding environment are used as the parameters specifying the occurrence possibility of intermediate events leading to a VCE. Factors such as area classification, degree of congestion of a plant and release rate are notably affecting the output results. Moreover, the proposed method benefits from experts' opinions in the estimation of the VCE possibility. A refrigeration cycle is used as the case study and the probability of VCE occurrence is determined for different scenarios. In this study, sensitivity analysis is performed on the model parameters to assess their effect on the final values of the VCE possibility. Furthermore, the results are compared with the results obtained using other existing models.     

新型高聚物煤自燃阻化剂的试验研究

煤堆自然发火是一个严重的经济和安全问题,是重大灾害之一.目前有许多采用阻化剂防止煤炭自燃的技术,但普遍存在阻化效果不稳定、寿命短等不足.本文选用合适的高聚物分子作为阻化剂,并以水玻璃、CaO、表面活性剂等为添加剂.进行双氧水氧化升温试验、程序升温氧化试验和阻化性试验,结果表明,这种新型阻化剂阻化效果良好,阻化率达90%以上.高聚物分子通过物理吸附、机械结合、化学吸附等作用使煤粒相互粘结,最后能在煤堆表面形成一定厚度和一定强度的固化层,覆盖在煤表面,阻缓氧气进入煤体,提高了对煤炭的阻化效果.这种阻化剂无毒无害、使用方便,具有良好的应用前景.     

管道内甲烷-空气预混爆炸燃烧的数值模拟

在实际生产过程中,有很多情况能使气体燃料与空气混合,达到可燃浓度,此时若有点火源存在,就可能酿成燃烧、爆炸灾害,造成严重的财产损失和人员伤亡.选取甲烷作为研究对象,选用空气作为氧化性气体,对其进行数值模拟.获得了不同时刻爆燃的压力场、温度场、密度场的变化数据,为工程上防爆、抑爆、泄爆提供了理论基础和数据.     

How team helping influences abusive and empowering leadership: The roles of team affective tone and performance

Leaders' perceptions of their teams are critical sources of contextual social information influencing leadership behaviors. In this paper, we extend affect-as-social-information theory to understand how and why team helping behaviors predict leaders' mistreatment of their teams in the form of abusive supervision and positive leader behavior in the form of empowering leadership, both through leaders' perceptions of team positive affective tone. In addition, based on social information processing, we examine the cue of leaders' perceptions of team task performance as a factor that helps us understand when the relationship between positive affective tone and leadership behaviors may be attenuated. In two text-based scenario studies, a video-based scenario study, and a multisource field study, we found evidence that team helping behavior is antecedent to abusive and empowering leadership behaviors and that this relationship is fully mediated by leaders' perceptions of team positive affective tone. Moreover, our results support team task performance as a factor that decreases the degree to which affective tone is related to abusive supervision. We discuss our findings as a caution to scholars' assumptions about the directionality of leader-team influence, emphasizing the need to acknowledge upward effects in workplace mistreatment research in the leader–team relationship.     

Towards a constructivist program in safety

This paper delves into the relationship between safety and constructivism. In the past 30 years, the constructivist discourse has become very popular but also controversial as it challenges some key categories associated with modernity, such as reason, objectivity, truth and reality. In the safety literature, several works advocate its use. This paper has three objectives. The first one is to reveal the existence of a constructivist discourse in the field of safety. It does this by bringing together scattered pieces of works from different authors who endorse and apply to various topics a position labelled as constructivist. However, and that is the paper’s second objective; it demonstrates that there is not only one constructivism, but several. In order to ground this contention, the paper proceeds with a multidisciplinary and historical approach. It is then argued that it is more appropriate not to conflate this diversity of constructivisms. The paper looks for a solution to this problem by providing a classification based on two groups of parameters: mild/strong and cognitive/social, defining four types. This step serves the third objective which consists in initiating a multifaceted constructivist program in safety composed of heterogeneous but related empirical and theoretical areas of investigations.     

电厂油库常用评价方法的探讨与比较

在我国大型火力发电厂的运行过程中,不可避免地都要使用到大量的柴油或重油等,作为储存油料的储油罐,在电厂始终是作为重大危险源进行管理的.在电厂评价过程中,油库的评价工作尤为重要,采用何种评价方法对油库进行合理有效的评价,是目前评价人员需要考虑的一个问题.