Simuliranje posledic izpusta nevarne snovi v programu ALOHA

Cimermančič, Monika (author), Huč, Sabina (mentor)

V okviru diplomskega dela sem s pomočjo računalniške simulacije obravnavala posledice izpusta nevarne snovi propan. Preučevala sem nezgodo iz rafinerije Feyzin, ki se je leta 1966 zgodila v Franciji, in velja za eno izmed najhujših katastrof v novejši zgodovini industrije. Nezgodo Feyzin sem simulirala v programu ALOHA, ki se uporablja za ocenjevanje posledic izpustov nevarnih snovi, na podlagi katerih se lahko načrtujejo ustrezni ukrepi v primeru izrednih dogodkov. Cilj diplomskega dela je bil oceniti posledice izpusta večje količine propana. Ocene posledic izpusta sem primerjala s podatki iz literature. Prav tako je bil cilj diplomskega dela ugotoviti, kakšen vpliv imajo meteorološki parametri oziroma različni letni časi na posledice izpusta propana. Pri simuliranju izpusta propana je bilo ugotovljeno nekoliko manjše območje vnetljivosti, kot je navedeno v literaturi. Pri simuliranju gorečega curka sem glede na literaturo dobila primerljive rezultate glede višine nastalega plamena in velikosti območij toplotnega sevanja. Nasprotno je pri simuliranju eksplozije BLEVE in nastanka ognjene krogle bila velikost ognjene krogle veliko večja od velikosti, navedene v literaturi. Enako so bila ugotovljena veliko večja območja toplotnega sevanja ognjene krogle. Razlogi za odstopanja so lahko omejitve programa ALOHA ali netočnost ter pomanjkljivost ocen, podanih v literaturi. Ugotovljeno je bilo, da imajo letni časi največji vpliv na velikosti območij nevarnih koncentracij propana, nekoliko manj na velikosti območij vnetljivosti propana ter najmanj na velikosti območij toplotnega sevanja. Območja nevarnih koncentracij in območja vnetljivosti propana so bila največja v zimskem in najmanjša v jesenskem času. Območja toplotnega sevanja gorečega curka in območja toplotnega sevanja ognjene krogle pa so bila največja v zimskem ter najmanjša v poletnem času. Ugotovila sem, da je nezgoda v Feyzinu povzročila največje posledice izpusta propana ravno, ko se je zgodila, to je v zimskem času. Rezultati ocenjevanja posledic so pokazali, da je imel izpust propana z eksplozijo BLEVE in nastankom ognjene krogle največje posledice, ki so segale v vseh letnih časih izven območja rafinerije, vse v poseljena območja. Zato je zelo pomembno, da so procesi, kjer obstaja tovrstna nevarnost, načrtovani z visoko stopnjo varnosti.

• Language: Slovenian
• Keywords: nezgoda Feyzin, ALOHA, izpust propana, meteorološki parametri, območja vpliva
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2021
• PID: 20.500.12556/RUL-131723
• COBISS.SI-ID: 87510019
• Publication date in RUL: 01.10.2021

Secondary language

• Language: English
• Title: Simulation of the consequences of the release of a hazardous substance in the ALOHA program

Abstract

In the frames of my thesis, I dealt with the consequences of the release of the dangerous substance propane with the help of a computer simulation. I studied the accident at the Feyzin refinery, which took place in France in 1966 and is considered one of the worst catastrophes in the recent history of the industry. I simulated the Feyzin accident in the ALOHA program, which is used to assess the consequences of releases of hazardous substances, based on which appropriate measures can be planned in the event of an emergency. The goal of the thesis was to assess the consequences of the release of large amounts of propane. I compared the estimates of the consequences of the release with the data from the literature. The goal of the thesis was also to determine the influence of meteorological parameters or different seasons on the consequences of propane release. During the simulation of the propane release, a slightly smaller flammable threat zone was found than reported in the literature. When simulating a jet fire, I obtained comparable results in terms of the height of the generated flame and the size of the threat zones of thermal radiation according to the literature. In contrast, during simulation of the explosion of BLEVE and the formation of a fireball, the size of the fireball was much larger than the size reported in the literature. Similarly, much larger threat zones of thermal radiation of the fireball were discovered. Deviations may be due to limitations of the ALOHA program or inaccuracy and lack of estimates given in the literature. The seasons were found to have the greatest impact on the size of threat zones of dangerous concentrations of propane, slightly less on the size of zones of flammability of propane and the least on the size of zones of thermal radiation. Zones of hazardous concentrations and zones of propane flammability were highest in winter and lowest in autumn. The zones of thermal radiation of the jet fire and the zones of thermal radiation of the fireball were the largest in winter and the smallest in summer. I found that the accident at Feyzin caused the greatest consequences of propane release just when it happened, that is, in the winter. The results of the impact assessment showed that the release of propane with the explosion of BLEVE and the formation of a fireball had the greatest consequences, extending in all seasons outside the refinery area, all in populated areas. Therefore, it is very important that processes where there is such a hazard are planned with a high level of safety.

• Keywords: Feyzin accident, ALOHA, propane release, meteorological parameters, threat zones