scholarly journals Elevated LNG Vapour Dispersion—Effects of Topography, Obstruction and Phase Change

Eng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 249-266
Author(s):  
Felicia Tan ◽  
Vincent Tam ◽  
Chris Savvides

The dispersion of vapour of liquefied natural gas (LNG) is generally assumed to be from a liquid spill on the ground in hazard and risk analysis. However, this cold vapour could be discharged at height through cold venting. While there is similarity to the situation where a heavier-than-air gas, e.g., CO2, is discharged through tall vent stacks, LNG vapour is cold and induces phase change of ambient moisture leading to changes in the thermodynamics as the vapour disperses. A recent unplanned cold venting of LNG vapour event due to failure of a pilot, provided valuable data for further analysis. This event was studied using CFD under steady-state conditions and incorporating the effect of thermodynamics due to phase change of atmospheric moisture. As the vast majority of processing plants do not reside on flat planes, the effect of surrounding topography was also investigated. This case study highlighted that integral dispersion model was not applicable as key assumptions used to derive the models were violated and suggested guidance and methodologies appropriate for modelling cold vent and flame out situations for elevated vents.

2013 ◽  
Vol 59 (4) ◽  
pp. 483-497 ◽  
Author(s):  
D. Prakash ◽  
P. Ravikumar

Abstract In this paper, transient analysis on heat transfer across the residential building roof having various materials like wood wool, phase change material and weathering tile is performed by numerical simulation technique. 2-dimensional roof model is created, checked for grid independency and validated with the experimental results. Three different roof structures are included in this study namely roof with (i). Concrete and weathering tile, (ii). Concrete, phase change material and weathering tile and (iii). Concrete, phase change material, wood wool and weathering tile. Roof type 3 restricts 13% of heat entering the room in comparison with roof having only concrete and weathering tile. Also the effect of various roof layers’ thickness in the roof type 3 is investigated and identified that the wood wool plays the major role in arresting the entry of heat in to the room. The average reduction of heat is about 10 % for an increase of a unit thickness of wood wool layer.


2019 ◽  
Vol 100 ◽  
pp. 00070 ◽  
Author(s):  
Elżbieta Romanik ◽  
Yaroslav Bezyk ◽  
Marcin Pawnuk ◽  
Urszula Miller ◽  
Agnieszka Grzelka

Odour concentration measurements in a chosen industrial source were made in this study using the method of dynamic olfactometry. The two different scenarios considered the variation of the odour emission rate as input for the dispersion model were compared for the period 2017 (before installation of the equipment for gas treatment) and 2018 (after implementation of purifying technologies). In this paper the odour impact range was determined by applying model calculations conducted in the Polish reference dispersion model – OPERAT FB software for the grid size 2 x 2 km. The conducted research shows a significant improvement in the odour impact range of chosen industrial source in year 2018 compared to 2017.


2017 ◽  
Vol 9 (10) ◽  
pp. 168781401772407 ◽  
Author(s):  
Ling Xie ◽  
Yifei Lv ◽  
Jun Lu ◽  
Yongcai Li ◽  
Shuli Liu ◽  
...  

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Mariana Campos Fontenelle ◽  
Alexandre de Sousa Fontenelle ◽  
Yago Machado Pereira de Matos ◽  
Fernando Feitosa Monteiro

RESUMO: O presente trabalho tem a proposta de avaliar a eficácia de duas metodologias de avaliação de risco de uma barragem no Nordeste Brasileiro no intervalo de 10 anos, baseando-se na inspeção e no nível de ameaça. Utiliza-se a metodologia Nível de Perigo da Barragem (NPB) para cálculo do nível de ameaça (Fontenelle, 2007) e para o cálculo do risco as metodologias da Companhia de Gestão dos Recursos Hídricos do Ceará (COGERH) e do Conselho Nacional de Recursos Hídricos (CNRH). Observa-se que o crescente número de barragens soma-se a preocupação com a segurança destas. Face a isto, utiliza-se a avaliação de risco como forma de priorizar ações de manutenção e recuperação. O estudo de caso ocorreu na Barragem Malcozinhado, localizada no município de Cascavel, no estado do Ceará. Com base na inspeção, calcula-se o nível de ameaça e o risco, compara-se estes com os resultados de 2006. Assim, observou-se o aumento no nível de ameaça, no entanto, o risco permaneceu, em geral, baixo, semelhante aos resultados de 2006. Este resultado se deve ao fato de que o número de anomalias aumentou, porém trata-se de uma barragem jovem, de pequeno porte e inspecionada regularmente.ABSTRACT: The present study has the proposal of evaluating the effectiveness of two methodologies of risk Assessment of a Brazilian Northeast dam in a range of 10 years, based on the inspection and the level of hazard. The methodology used for calculating the hazard level is the Dam Hazard Level (NPB). In addiction, in order to evaluate the risk is used the methodology of the Water Resources Management Company of Ceará (COGERH) and the methodology of National Resources Council Water (CNRH). The number of dams is increasing with to the concern for their safety. In view of this, risk assessment is used as a tool to prioritizing maintenance and recovery actions. The case study occurred in the Malcozinhado Dam, located in the municipality of Cascavel, in the state of Ceará. Based on the inspection, the level of hazard and risk is calculated, compared to the results for 2006. Thus, the increase in the level of hazard was observed, but the risk remained generally low, similar to 2006 result. This result is due to the fact that the number of anomalies has increased, but it is a young, small and regularly inspected dam.


2021 ◽  
Vol 9 ◽  
Author(s):  
Jörn Behrens ◽  
Finn Løvholt ◽  
Fatemeh Jalayer ◽  
Stefano Lorito ◽  
Mario A. Salgado-Gálvez ◽  
...  

Tsunamis are unpredictable and infrequent but potentially large impact natural disasters. To prepare, mitigate and prevent losses from tsunamis, probabilistic hazard and risk analysis methods have been developed and have proved useful. However, large gaps and uncertainties still exist and many steps in the assessment methods lack information, theoretical foundation, or commonly accepted methods. Moreover, applied methods have very different levels of maturity, from already advanced probabilistic tsunami hazard analysis for earthquake sources, to less mature probabilistic risk analysis. In this review we give an overview of the current state of probabilistic tsunami hazard and risk analysis. Identifying research gaps, we offer suggestions for future research directions. An extensive literature list allows for branching into diverse aspects of this scientific approach.


2003 ◽  
Vol 36 (3) ◽  
pp. 261-272 ◽  
Author(s):  
Chit Ko Ko ◽  
Phil Flentje ◽  
Robin Chowdhury

2021 ◽  
pp. 123-136
Author(s):  
Bruce Lyon ◽  
Georgi Popov

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