Assessment of the effect of technical and management characteristics on the frequency of release from piping: An application to a gas storage facility

The assessment of the frequencies of release from piping due to losses of containment is an essential step in the preparing Safety Reports, drawn up as required by the so-called “Seveso” Directive. These are usually calculated starting from the frequencies of random rupture included in international databases and are not plant-specific, furthermore, the quantification of the effect of the safety management system of the facility is not easy. A simple and flexible approach quantifying technical and management characteristics of the plant has been proposed by Milazzo and co-workers in 2010; it is based on the modification of the frequency taken from literature, through the use of the percentages of failure causes actually possible in that plant, and the judgment about their management. The data about the failure causes are taken from the literature and modified by using corrective factors to adapt them to the industrial context. To make possible the application of the method to a large number of major-hazard industry types, some aspects of the approach needed to be improved; these have been identified during a development project coordinated by RINA Consulting, on behalf of Saipem, with the collaboration of the University of Messina. The improvement of the approach focused on two main points, the development of a method to calculate the corrective factors for the failure causes associated with corrosion and erosion phenomena and the strengthening of the methodology for the formulation of the judgment about the safety management. This paper illustrates the fully improved method, as well as an application to a typical gas storage plant.     

湖南省山洪灾害经济损失评价

山洪灾害是湖南省山丘区经济可持续发展的重要制约因素。文章采用山洪灾害经济损失的不稳定度Us和灾害直接经济损失占应得GDP百分比的平均数Cr,构建了湖南省山丘区山洪灾害灾损度指数DELI。研究表明,Us高值区和Cr高值区在空间上明显错位,前者为湘西自治州、怀化、张家界、郴州等,后者是张家界、娄底、邵阳等。根据DELI等级...     

降雨-径流与非点源污染物浓度及流失量关系分析——以铁岭市柴河水库上游流域为例

以铁岭市柴河水库上游集水区域为研究对象,利用铁岭市柴河堡水文站降雨时节实测的暴雨径流数据、泥沙数据、污染物浓度数据进行分析,侧重研究降雨时节暴雨径流量与主要污染物浓度及污染物瞬时流失量之间的关系,以期为柴河流域农业非点源污染控制提供参考。研究结果表明:暴雨期内,非点源污染物浓度及瞬时流失量与径流峰值几乎同步出现,它们之间存在着非常密切的关系。     

农药杀虫单的稻田流失规律研究

通过测坑、人工降雨等手段，对水溶性农药杀虫单的稻田消解动态、渗漏流失和径流流失等进行了研究。结果表明，(1)无水稻时，杀虫单在稻田水中消解的半衰期为0．76d；分蘖初期，杀虫单在稻田水中降解的半衰期为1．02d；平均为0．89d。(2)杀虫单的渗漏流失量在用药后8d内可达总用药量的7％—10％，平均为8．48％。(3)极端情况下，用药当天如果遇暴雨(50mm雨量)，杀虫单的径流流失量将达到用药量的30％左右。杀虫单的渗漏损失不可避免，故其流失控制应从径流损失着手，尽量避免在可能有暴雨的当天或雨前1—2d用药。     

基于传声器阵列的声源定位技术的应用

基于传声器阵列的声源定位技术中的两个主要方法,STSF和Beamforming声源定位技术两者的实现方法不同。通过对STSF和Beamforming声源定位技术的推导,给出了两种测量技术适用的频率范围和空间范围,从理论上对其应用范围的差异进行了说明,并提出在实际测量中如何选择合适的声源定位方法。结合两种测量技术的特点,提出声源定位技术下一阶段研究的重点。     

地铁停车场上盖物业开发声环境影响评价研究

占地面积大、交通便利的地铁停车场上盖物业开发越来越受到青睐。以南京市江宁大学城停车场上盖物业为例,对受到地铁停车场、高架地铁和公路3方面噪声源影响的上盖物业进行了声环境影响预测分析。得出:该项目受到停车场噪声影响的最大声级达61.9dB(A),受到高架地铁噪声和公路噪声叠加影响的等效声级昼间可达67.7dB(A),夜间可达63.6dB(A)。在确保落实相应防护措施的前提下,地铁停车场上盖物业在声环境上总体上具有可行性。     

降低油品储运损耗 改善大气环境

从石油开采到成品油进入清费的过程中，损耗量约占原油量的3％－5％，其中储运过程中的损耗占总耗的40％－50％，着重论述了油品储运过程中降低损耗的措施，以减少经济损失和对环境的破坏。     

浅谈如何有效改善城乡声环境质量

改善声环境质量的迫切性和重要性;阐述了防治噪声污染、改善声环境质量的途径与措施.     

经环境污染损失调整的重庆市绿色GDP核算研究及应用

传统的GDP核算模式建立在资源耗减、环境破坏和公众健康不断透支的基础之上,不能体现经济活动对自然资源的消耗和对生态环境造成的破坏。为了将环境污染损失纳入GDP核算体系,以2010年重庆市绿色GDP核算为例,运用虚拟治理成本法进行环境价值量核算。结果表明,基于环境污染损失调整后的重庆市绿色GDP为7920.28亿元,污染扣减指数为0.4%。     

Dynamic behaviour of direct spring loaded pressure relief valves in gas service: II reduced order modelling

A previous study of gas-service direct-spring pressure relief valves connected to a tank via a straight pipe is continued by deriving a reduced-order model for predicting oscillatory instabilities such as valve flutter and chatter. The reduction process uses collocation to take into account a finite number N of acoustic pressure waves within the pipe, resulting in a set of 2N+3 ordinary differential equations. Following a novel non-dimensionalization, it is shown analytically that the model can exhibit, at experimentally realistic parameter values, instabilities associated with coupling between the valve and acoustic waves in the pipe. The thresholds for each instability are such that for a given flow rate, the first mode to go unstable as the inlet pipe length increases is the quarter-wave mode, then a three-quarter wave, a 5/4-wave etc. Thus the primary mode of instability should always be due to the quarter wave. In the limit of low flow rates, a simple approximate expression is found for the quarter-wave instability threshold in the form of inlet pipe length against mass flow rate. This threshold curve is found to agree well with simulation of the full model. For higher flow rates there is a need to include fluid convection, inlet pressure loss and pipe friction in order to get good agreement. The reduced model enables the dependence of the stability curve on key dimensionless physical parameters to be readily computed.