عنوان پایان‌نامه
تحلیل خطرپذیری در یک واحد فرایندی با استفاده از روش اف تی ای-لوپا مطالعه موردی واحد آمونیاک پالایشگاه نفت پارس
- رشته تحصیلی
- ایمنی، بهداشت و محیط زیست
- مقطع تحصیلی
- کارشناسی ارشد
- محل دفاع
- کتابخانه دانشکده محیط زیست شماره ثبت: ENV 1130;کتابخانه مرکزی -تالار اطلاع رسانی شماره ثبت: 62781
- تاریخ دفاع
- ۰۵ بهمن ۱۳۹۲
- دانشجو
- محمدحسن گلیج
- استاد راهنما
- حمیدرضا جعفری, سعید گیوه چی
- چکیده
- همواره در صنایع و تأسیسات شیمیایی، مخاطرات بالقوه‌ای وجود دارند که می‌توانند موجب بروز جراحت، صدمات جانی و خسارت‌های مالی شوند. از میان مخاطرات موجود در صنایع شیمیایی، حوادث مربوط به کوره‌ها و تجهیزات حرارتی به علت شرایط کاری، عملکرد در دما و فشار بالا و از طرف دیگر تنش‌ها و خوردگی‌ها همیشه جزء نگرانی صنایع بوده است. خطرات این گونه تجهیزات عمدتاً بصورت حوادثی مانند آتش‌سوزی، انفجار یا نشت مواد سمی بروز می‌کند. به همین علت مدیریت ریسک در این صنایع باید بر مبنای تجزیه و تحلیل خطر و ارزیابی پیامدهای ناشی از آن صورت گیرد. موضوع مورد مطالعه در این پژوهش شناسایی مخاطرات، تجزیه تحلیل ریسک‌ها، احتمال وقوع حادثه، بررسی حفاظ‌ها و سیستم‌های ایمنی موجود در واحد آمونیاک (جذبی) پالایشگاه نفت پارس واقع در استان تهران با استفاده از تکنیک‌های FTA & LOPA می‌باشد. روش FTA، یک روش تجزیه و تحلیل خیلی دقیق با جزئیات کامل بوده و یک مدل سمبلی به شکل درخت است که از بالا به پایین ایجاد شده و رویدادهای خطرناک را نشان می‌دهد. روش LOPA، روش نیمه کمی آنالیز لایه‌های حفاظتی که برای شناخت و تجزیه و تحلیل لایه‌های حفاظتی به کار می‌رود و این امکان را فراهم می‌آورد که در بررسی یک فرآیند در مورد کفایت حفاظ‌های ایمنی یا نیاز به لایه‌های بیشتر حفاظتی تصمیم‌گیری شود.
- Abstract
- There are potential risks in the chemical industries which create the financial and criminal damages. Among the risks present in the chemical industries, the events related to the furnaces and heat equipment's were some worries of industries due to the work conditions, the performance in the temperature and high pressure and in other hand the stresses the risks of such equipment's are occurred as the events like fire, explosion or leakage of toxic materials. Because of this, the risk management in these industries should be based on the risk analysis and evaluating its results. The studied topic in this study is the risk identification, the risk Analysis, the event occurrence possibility. The studying the fences and safety systems present in the ammonia unit in pars petroleum refinery located in Tehran by using FTA & LOPA techniques. FTA method is the exact analysis method with the complete details and is a symbol model in the tree shape which has been created from up to down and indicates the dangerous events. LOPA method is a semi quantitative method of protection layers analysis used to identify and analyses the protection layers and allows the sufficiency of safety fences or the need to the more protection layers to be decided in studying one process. In this study, at first by collecting the necessary information's and preparing the risk preliminary list of studied industry. The explosion of ammonia furnace was selected as the main event and its fault tree was depicted in Open FTA software. In the next Stage, all the dangerous paths were identified from the final events resulted in the explosion event by the software analytical facilities and finally the possibility of explosion occurrence in above industry was calculated by entering the quantitative data. Then, LOPA technique was used to identify the sufficiency of present protection layers. 10 scenario accompanied by the starter events were selected from the risk qualitative studies conducted in the levels of fault tree analysis technique middle event and the risk preliminary list in this study. Then, every one of scenarios were entered to LOPA work sheets and calculated by using the quantitative data obtained from the expert opinions, the same studies and previous records of possibility in every scenario. In the evaluation by FTA method, the occurrence possibility level of main event (explosion of ammonia furnace) in this study was calculated equal to 1/2506884 × 10-2 year which is equivalent to one explosion in every 80 years for every one of ammonia unit furnaces and are placed in the top with 40/8% according to the qualitative results obtained from the classification and analysis of fault tree events in view of instructional defects importance. In evaluation by LOPA method, among the selected scenarios, two scenarios of ammonia furnace explosion due to the sudden events occurrence with 1×10-5 frequency and defect of furnace reflex pump with 1× 10-4 frequency had the amounts higher than the risk tolerance standard which requite the amendatory operations to reduce the results. Key words: The fault tree analysis, protection layers analysis, safety, furnace and explosion
