Combustion products toxicity risk assessment in an offshore installation

Products of a hydrocarbon fire accident have both chronic and acute health effects. They cause respiratory issues to lung cancer. While fire is the most frequent phenomenon among the offshore accidents, predicting the contaminants’ concentration and their behavior are key issues. Safety measures design, such as ventilation and emergency routes based only on predicted contaminants’ concentration seems not to be the best approach. In a combustion process, various harmful substances are produced and their concentration cannot be added. The time duration that any individual spends in different locations of an offshore installation also varies significantly. A risk-based approach considers the duration a person is exposed to contaminants at various locations and also evaluates the hazardous impacts. A risk-based approach has also an additivity characteristic which helps to assess overall risk.Through the current study, an approach is proposed to be used for risk assessment of combustion products dispersion phenomenon in a confined or semi-confined facility. Considering CO, NO₂ and CH₄ as the contaminants of concern, the dispersion of the substances over the layout of the facility after a LNG fire is modeled. Considering different exposure times for three major parts of the facility including the processing area, office area and the accommodation module, the risk contours of CO, NO₂ and CH₄ over the entire facility are developed. The additivity characteristic of the risk-based approach was used to calculate the overall risk. The proposed approach helps to better design safety measures to minimize the impacts and effective emergency evacuation planning.     

火灾中聚合物材料热解对汽油辨识的影响分析

火灾中聚合物材料的燃烧过程产生的热解产物,从而增加化学分析谱图的复杂性,对助燃剂鉴定造成干扰。针对常见的聚合物材料开展了一系列燃烧实验,对其在燃烧过程中的热解机理进行了分析,并通过汽油存在条件下的聚合物材料燃烧实验分析了热解对汽油辨识产生的干扰。     

受火方式和防火层对梁柱全焊节点抗火性能影响分析

梁柱节点作为钢结构的重要组成部分,在火灾下极易遭到破坏。全焊节点具有较好的塑性变形能力,且抗震性能较好,在高烈度地震地区广泛应用。采用有限元法对梁柱全焊节点抗火性能进行数值模拟,研究不同受火方式下全焊节点的力学行为,揭示不同受火方式时梁柱各节点处温度变化规律,并对比分析有无防火层对全焊节点温度的影响规律。研究结果表明:不同受火方式对全焊节点温度影响较大。节点全部受火时节点各处温度变化曲线基本接近,结构各部位温差较小,整体处于高温状态;梁柱两面受火时受火面温度马上升高,远离受火位置的节点温度升高缓慢,节点各处温差较大。将节点全部受火与不受火进行对比发现,节点全部受火时节点各处应力明显大于不受火情况,温度升高使节点承载能力下降。在柱内壁和梁下侧施加防火层,升温最快的是防火层区域,且有防火层区域节点温度整体低于无防火层节点,对节点施加防火层可以有效降低整体结构升温。     

Non-linear ecological processes, fires, environmental heterogeneity and shrub invasion in northwestern Patagonia

The emergent behaviors of nature are not only the sum of interactions among ecosystem parts but also depend on the organization of these interactions. Fire, climate and vegetation patterns produce non-linear fire propagation across the landscape. Environmental heterogeneity, like outcrop presence and hare density, increases landscape patchiness and makes possible the occupation of fire refuges by plants, like Fabiana imbricata shrubs. We monitored shrub recruitment and cover during nine postfire years in northwestern Patagonia grasslands and we studied the long-term population dynamics under different environmental conditions through a matrix model, exploring different fire frequencies and spring precipitation regimes. Both, the field monitoring and the model seem to confirm the relationships between shrub invasion and fire. The climate change forecast predicts an increase in the frequency of El Niño Southern Oscillation phenomena that could causes more coupled fires—rainy springs in northwestern Patagonia, and consequently, more recruitment windows for shrubs, like F. imbricata. The matrix model also indicates that this scenario would be the most favourable for shrub invasion. Our results contribute to the knowledge of the ecosystem properties and processes, providing useful information to improve the grasslands sustainable use.     

Temporal scaling behavior of human-caused fires and their connection to relative humidity of the atmosphere

It has been found that many natural systems are characterized by scaling behavior. In such systems natural factors dominate the event dynamics. But in countries with high population density such as China and Japan, more than 95% of the forest fire disasters are caused by human activities. Furthermore, with the development of society, the wildland-urban interface (WUI) area is becoming more and more populated, and the forest fire is much connected with urban fire. Therefore exploring the scaling behavior of fires dominated by human-related factors is very challenging. The present paper explores the temporal scaling behavior of forest fires and urban fires in Japan. Our findings point out that although the human factors are the main cause, both the forest fires and urban fires exhibit time-scaling behavior. Similar distribution law characterizes the relative humidity.     

Will climate change overwhelm fire management capacity?

Using anomalies calculated from General Circulation Model (GCM) climate predictions we developed scenarios of future fire weather, fuel moisture and fire occurrence and used these as the inputs to a fire growth and suppression simulation model for the province of Ontario, Canada. The goal of this study was to combine GCM predictions with the fire growth and suppression model to examine potential changes in area burned in Ontario due to climate change, while accounting for the large fire suppression activities of the Ontario Ministry of Natural Resources (OMNR). Results indicate a doubling of area burned in the Intensive and Measured fire management zones of Ontario by the decade of 2040 and an eightfold increase in area burned by the end of the 21st century in the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC SRES) A2 scenario; smaller increases were found for the A1b and B1 scenarios. These changes are driven by increased fire weather conducive to large fire growth, and increases in the number of fires escaping initial attack: for the Canadian GCM's business-as-usual (A2) scenario, escaped fire frequency increased by 34% by 2040 and 92% by the end of the 21st century. Incorporating more detail on large fire growth than previous studies, our model predicts higher area burned under climate change than do these previous studies, as large numbers of high-intensity fires overwhelm suppression capacity.     

关于高层建筑中几个消防问题的探讨

根据目前国内高层建筑的状况,结合所发生的火灾特点,提出了在消防方面应引起重视的几个问题。还给出了处理这些问题的建议和防治方法,并指出在高层建筑中,若所有电梯都设计成消防电梯,同时少建裙房,必将有助于减少火灾造成的损失     

林火预防与扑救投资的成本效益分析

针对某一林区,确定其林木管理目标,以及为达到此目标对林火监测与扑救系统的要求,从而确定森林防火的资金投入。分析了加大森林防火投入前后森林火灾损失与扑求费用的变化。     

森林可燃物可持续管理技术理论与研究

实现森林可燃物可持续管理是减少和控制森林火灾的基础。本文介绍了基于可物管理的防火林带和计划火烧的预防和控制森林火灾方法。     

电解铝车间消防车道的布置

根据电解铝生产的特点及对电解铝厂火灾事故的了解,确定电解铝车间的火灾危险属丁类。提出电解铝车间消防车道的布置原则是不设环形消防车道,采用单侧消防车道,或利用交通道路做消防车道。并对电解铝车间的消防车道布置作了具有代表性的实例剖析。