مطالعه عددی تأثیر سازه پیک کولر بر جریان هوا و بازدهی برج خنک‌کن خشک

نوع مقاله : مقاله علمی

نویسندگان
1 گروه مهندسی مکانیک،دانشکده مهندسی، دانشگاه بزرگمهر قائنات، قائن، ایران
2 گروه مهندسی مکانیک- دانشکده فناوری‌های نوین - دانشکده صنعتی قوچان
چکیده
در برج‌های خنک‌کن خشک نیروگاهی، وجود پیک کولر به‌منظور افزایش کارایی سیستم‌های خنک‌کننده و بهبود عملکرد حرارتی در شرایط دمای بالا و با معکوس کردن جریان داخل آن در زمستان برای حفاظت از یخ زدن مبدل‌های اطراف برج ضروری است؛ اما موقعیت مناسب این سازه و اثر آن روی عملکرد از اهمیت خاصی برخوردار است. در این مقاله، اثر سازه پیک کولر بر جریان هوا و بازدهی برج خنک‌کن خشک مطالعه شده است. بدین منظور جریان شناوری با در نظر گرفتن انتقال حرارت از رادیاتورهای برج برای دو حالت با و بدون پیک کولر با استفاده از نرم‌افزار ANSYS Fluent 22 انجام‌شده است. جهت مد‌ل‌سازی اثر آشفتگی از
 مدل k-ε با در نظر گرفتن اثرات شناوری و همچنین اثر افت فشار و انتقال حرارت رادیاتور با استفاده از شرط مرزی رادیاتور و اثر فن پیک کولر نیز با شرط مرزی فن دوبعدی وارد محاسبات شده است. نتایج شبیه‌سازی‌ها نشان‌ می‌دهد سازه پیک کولر تأثیر منفی قابل توجهی بر دبی جریان داخل برج و در نتیجه کاهش انتقال حرارت از مبدل‌های دلتا شکل اطراف برج (با صرف‌نظر از انتقال حرارت مبدل‌های داخل پیک کولر) دارد. نتایج نشان می‌دهد به دلیل جریان‌های گردابی اطراف سازه پیک کولر و انسداد جریان، دبی جریان روی مبدل‌های دلتا شکل 8 درصد کاهش می یابد. همچنین نتایج نشان می‌دهد علی‌رغم کاهش دبی و انتقال حرارت از رادیاتورهای دلتا شکل، در مجموع دبی کل برج و انتقال حرارت آن به‌دلیل استفاده از فن داخل پیک کولر و افزایش 10 درصدی سطح رادیاتورها، در مجموع پیک کولرها اثر مثبتی دارند ولی می‌توان با انتقال آن‌ها به سمت مرکز برج این اثرات منفی را کاهش داد.
کلیدواژه‌ها
موضوعات

عنوان مقاله English

Numerical Study of the Effect of Peak Cooler Structure on Airflow and Efficiency of Dry Cooling Tower

نویسندگان English

Mohammad Reza Zangooee Motlagh 1
Seyed Mohammad Javadi 2
1 Department of Mechanical Engineering,Faculty of Engineering, Bozorgmehr University of Qaenat, Qaen, Iran.
2 Department of Mechanical Engineering, Faculty of Advanced Technologies, Quchan University of Technology, Quchan, Iran
چکیده English

In dry cooling towers of power plants, the presence of a peak cooler is essential to increase the efficiency of cooling systems and improve thermal performance in high-temperature conditions. Also reversing the flow, protect the surrounding heat exchangers from freezing in winter. The appropriate position of this structure and its effect on performance has the particular importance. In this paper, the effect of the peak cooler structure on airflow and the efficiency of the dry cooling tower has been studied. For this purpose, buoyancy-driven flow considering heat transfer from the tower radiators for two cases, with and without a peak cooler, was simulated using ANSYS Fluent 22 software. In this paper, the turbulence and buoyancy effects is considered using k-ε model, as well as with using  radiator boundary condition, the effect of pressure drop and heat transfer of the radiator is considered. The results show that the peak cooler structure has a significant negative impact on the flow rate inside the tower and consequently reduces heat transfer from the delta-shaped heat exchangers around the tower (excluding heat transfer from the heat exchangers inside the peak cooler). Also, due to vortex flows around the peak cooler, the flow rate over the delta-shaped heat exchangers decreases approximately 8%. With despite of the decrease in flow rate and heat transfer from the delta-shaped radiators due to the structure of peak cooler, the total flow rate of the tower and its heat transfer increases because of the using the fan inside the peak cooler and increasing 10% in the radiator surface area. The negative effects can be reduced by moving them towards the center of the tower.

کلیدواژه‌ها English

Cooling Tower
Airflow
Buoyancy
Peak Cooler
Simulation
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  • تاریخ دریافت 24 دی 1403
  • تاریخ بازنگری 26 اسفند 1403
  • تاریخ پذیرش 25 فروردین 1404
  • تاریخ اولین انتشار 25 فروردین 1404
  • تاریخ انتشار 25 فروردین 1404