بررسی عددی پیش گرمکن هوا جهت تعیین تشکیل شبنم در ورقهای موجدار برای تعیین سطوح با امکان خوردگی

نوع مقاله : مقاله پژوهشی

نویسندگان

حسن محمدی سیبنی

حمید رضا نظیف

دانشکده فنی و مهندسی، گروه مهندسی مکانیک، دانشگاه بین المللی امام خمینی.

10.22067/jacsm.2025.90816.1302

چکیده

در دیگهای بخار بمنظور افزایش راندمان نیروگاه، هوای مورد نیاز برای احتراق باید پیشگرم شود. در تحقیق حاضر پیشگرمکن هوای گردشی به منظور کاهش خوردگی ورق های موجدار آن مورد بررسی قرار گرفته است. به کمک دینامیک سیالات محاسباتی شبیه سازی سه بعدی پیشگرمکن در مختصات مرجع متحرک انجام شد. با فرض عایق بودن دیواره ها و تأثیر تشعشع، حل معادلات پیوستگی، اندازه حرکت و انرژی انجام شد. نتایج مقاله با اطلاعات تجربی همخوانی خوبی دارند. سطوح مستعد پدیده خوردگی، شناسایی شدند. بیشترین خوردگی معمولا در ناحیه خروج محصولات احتراق از ماتریس رخ می‌دهد. لذا حداقل دمای خروجی گاز از نقطه نظر تشکیل نقطه شبنم مشخص شد. نتایج عددی نشان‌ دهنده تأثیر صفحه جداکننده، سرعت دورانی، دمای هوا و گاز ورودی بر عملکرد و توزیع دمای پیش گرم‌کن هستند. اثر سرعت چرخشی بر شروع چگالش سیال و نقطه شبنم نشان داد که تغییر سرعت دوران، فرآیند خوردگی را کاهش نمی دهد. افزایش سرعت دورانی روتور، در محدوده ی 5/0تا 6 دور بر دقیقه بازده را تا 84% افزایش می دهد.

کلیدواژه‌ها

پیش گرمکن

ژانگستروم

نقطه شبنم

دینامیک سیالات محاسباتی

موضوعات

• انتقال حرارت

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عنوان مقاله English

Numerical Investigation of Air Preheater to Determine the Formation of Dew in Corrugated Sheets in Order to Determine the Surfaces with the Possibility of Corrosion

نویسندگان English

hasan mohammadi siboni

Hamid Reza Nazif

Technical and Engineering Faculty, Department of Mechanical Engineering, Imam Khomeini International University Qazvin, Iran

چکیده English

In steam boilers, in order to increase the efficiency of the power plant, the air required for combustion must be preheated. In this research, circulating air preheater has been investigated in order to reduce the corrosion of its corrugated sheets. With the help of computational fluid dynamics, three-dimensional simulation of the preheater was performed in moving reference coordinates. Assuming the insulation of the walls and the effect of radiation, solving the equations of continuity, momentum and energy was done. The presented results are in good agreement with the experimental data. Corrosion of susceptible surfaces were identified. The most corrosion usually occurs in the exit area of combustion products from the matrix. Therefore, the minimum gas outlet temperature was determined from the point of view of dew point formation. The corrosion process cannot be prevented by changing the rotation speed. Increasing the rotational speed of the rotor in the range of 0.5 to 6 rpm increases the efficiency by 84%,

کلیدواژه‌ها English

Preheater

Ljungstrom

Dew Point

CFD (Computational Fluid Dynamics)

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