نشریه مهندسی مکانیک امیرکبیر

نشریه مهندسی مکانیک امیرکبیر

بررسی عملکرد حرارتی دو برج خنک‌کن خشک جریان طبیعی کنار هم با دو چیدمان محیطی دایروی و بیضوی از رادیاتورها

نوع مقاله : مقاله پژوهشی

نویسندگان
دانشکده مهندسی مکانیک، دانشگاه بوعلی سینا، همدان، ایران
چکیده
وزش باد می‌تواند باعث کاهش قابل ‌توجه کارایی حرارتی برج‌های خنک‌کن خشک جریان طبیعی شود. با وجود ارائه راهکارهای مختلفی در ارتباط با بهبود عملکرد حرارتی برج‌های منفرد و چندتایی، اثر چیدمان بیضوی رادیاتورها روی عملکرد دسته برج‌های خنک‌کن بررسی نشده است. در این پژوهش، عملکرد حرارتی دو برج خنک‌کن خشک جریان طبیعی کنار هم با چیدمان بیضوی رادیاتورها در مقایسه با چیدمان متداول دایروی، به روش شبیه‌سازی عددی سه‌بعدی بررسی شد. نتایج نشان داد حضور برج مجاور موجب کاهش نرخ انتقال حرارت هر برج نسبت به وضعیت بدون حضور برج دیگری است، که ناشی از تداخل جریان در فاصلۀ بین دو برج است. با این حال، در سرعت‌های باد 7 و 10 متر بر ثانیه، چیدمان بیضوی رادیاتورها عملکرد حرارتی بهتری نسبت به چیدمان دایروی نشان می‌دهد. پیش‌بینی شد که در سرعت‌های زیاد بالا، برج خنک‌کن بیضوی کارایی حرارتی را نسبت به برج خنک‌کن دایروی از18/2 تا 29/5درصد افزایش خواهد داد. تحلیل جزئیات میدان جریان نشان داد که افزایش میزان عبور هوای گرم از روی رادیاتورهای پشتی برج خنک‌کن بیضوی، موجب افزایش متوسط گرادیان دما در طرفین رادیاتورها شده، و در نتیجه بهبود نرخ انتقال حرارت آن‌ها را در پی دارد. انتخاب چیدمان بهینه رادیاتورهای برج‌های خنک‌کن به سرعت غالب وزش باد در محل وابسته است و می‌تواند نقش مهمی در ارتقای عملکرد حرارتی برج‌های خنک‌کن خشک جریان طبیعی داشته باشد.
کلیدواژه‌ها
موضوعات

عنوان مقاله English

Thermal performance assessment of two side-by-side natural draft dry cooling towers with circular and elliptical periphery radiator arrangements

نویسندگان English

Yaser Farahani
Mohsen Goodarzi
Faculty of Engineering, Bu-Ali Sina University, Hamedan, Iran
چکیده English

Wind significantly deteriorates thermal performance of natural draft dry cooling towers (NDDCTs). Although various approaches have been proposed to enhance the performance of single and multiple cooling towers, the effect of modifying the geometric arrangement of the radiators has not been comprehensively investigated. In this study, the thermal performance of two side-by-side natural draft dry cooling towers with an elliptical radiator arrangement was numerically compared with that of a conventional circular arrangement using three-dimensional CFD simulations. Results revealed that the presence of an adjacent tower leads to a reduction in the heat transfer rate of each individual tower compared to the isolated (single-tower) condition, highlighting the significant impact of flow interference between the towers. However, at wind speeds of 7 and 10 m/s, the elliptical arrangement outperformed the circular layout. Under high-wind conditions, the elliptical tower improves the thermal efficiency by approximately 18.2% to 29.5% compared to the conventional circular tower. Detailed flow field analysis revealed that the enhanced passage of warm air over the rear radiators in the elliptical arrangement increased the average temperature gradient along the lateral surfaces of these radiators, thereby improving their heat transfer rate. The optimal radiator arrangement depends on the prevailing wind conditions at the site and plays a critical role in improving the thermal performance of the cooling towers.

کلیدواژه‌ها English

Dry Cooling Tower
Elliptical Cooling Tower
Circular Cooling Tower
Windy Condition
Side-by-Side Layout
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