مدلسازی رشد فیلم بخار ایجاد شده براثر تماس کره داغ فلزی با آب در مخازن تحت فشار

نویسندگان

دانشگاه سمنان

چکیده

تماس یک جسم داغ (مانند ذرات فلز مذاب) با یک سیال خنک و نسبتاً فرارتر (مانند آب) در صنایع ریخته گری فلزات، کاغذسازی و در رآکتورهای هسته ای محتمل می باشد. انتقال حرارت بسیار شدید و سریع ناشی از این تماس می‌تواند فشار داخل فیلم بخار تشکیل شده بر روی ذره داغ را در مدت زمان اندکی افزایش دهد و منجر به رخداد پدیده انفجار بخار همراه با ایجاد موج فشاری شدیدی داخل مخزن حاوی ماده فرارتر ‌گردد. در این مقاله ابتدا مدل ریاضی مسئله برخورد کره داغ فلزی کوچک از جنس مس با آب بدست آمده و سپس آثار تغییر فشار مخزن نگهدارنده آب بر روی تغییرات شعاع فیلم بخار، فشار درون فیلم بخار و دمای اشباع مرز بین فازی بررسی شده است. در انتها نیز نتایج رشد فیلم بخار و فشار درون این فیلم برای رخداد چنین پدیده ای در نیروگاههای هسته ای که فشار سیال خنک کن میله های سوخت آن بین 60 تا 150 بار می باشد، مورد بررسی قرار گرفته است. بر اساس نتایج بدست آمده در فشارهای خیلی بالای مخازن، پالس فشار درون فیلم بخار در زمان کوتاهی به شدت افزایش مییابد و احتمال رخداد پدیده انفجار بخار را بالا می‌برد.

کلیدواژه‌ها


عنوان مقاله [English]

Modeling Growth of A Vapor Film Formed in Contact between Hot Metallic Sphere and Water in The Pressure Vessels

نویسندگان [English]

  • Mojtaba Biglari
  • Ali Jahangiri
چکیده [English]

Creation and growth of vapor film in contact between hot objects and liquids is possible in many industries, including nuclear reactors, metals casting industries and paper production. Due to severe heat transfer from a hot objects (as droplets of molten metal) in contact with a coolant and relatively volatile matter (like water), the pressure inside vapor film formed on hot sphere increases at very short time and result in, sudden pressure wave inside related substance storage structure is created and so this wave may lead to destruct the storage structure. In this paper First, the mathematical model of problem is obtained and then conclusion of numerical solution and previous studies is compared. Then, the effects of changing various pressures in vessels On the vapor film radius, vapor film pressure is investigated and finally this model is developed for contact between reactor coolant and hot objects in such nuclear power plants in which pressurized water is 60 to 150 bars. Results show that in case of high pressure inside vessel, the pressure inside vapor film increases to high values in a very short time.

کلیدواژه‌ها [English]

  • Hot sphere drop
  • Vapor film
  • Vapor film pressure
  • Saturation Temperature
  • Phase interface boundary
  • Sudden heat transfer
 

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