بررسی عددی و دوبعدی تاثیرات چرخش سوخت روی ساختار و ویژگی‌های زیست‌محیطی یک شعله نفوذی گازی

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی مکانیک، دانشگاه گیلان، رشت، ایران

چکیده

تاثیر مثبت چرخش واکنشگرهای ورودی به محفظه احتراق بر نرخ اختلاط سوخت و هوا در تحقیقات پیشین به­صورت گسترده­ای مورد بحث قرار گرفته است. اما، این تحقیقات اغلب بر چرخش هوا متمرکز بوده­اند. کار حاضربه ­صورت عددی به بررسی تاثیر چرخش سوخت بر ساختار شعله و نشر آلاینده­های یک شعله نفوذی می­پردازد، در حالی که میزان چرخش هوا ثابت نگه داشته می­شود. نتایج نشان می­دهد که افزایش چرخش سوخت منجربه افزایش نرخ اختلاط سوخت و هوا، افزایش پهنای شعله، افزایش دمای بیشینه شعله، کاهش نشر مونوکسیدکربن و کاهش طول شعله می­شود. اما، منحنی تغییرات میزان نشر اکسیدنیتروژن با چرخش سوخت دارای یک حداقل در چرخش­های میانی است. همچنین، نتایج نشان می­دهد که چرخش هم­جهت سوخت و هوا، در مقایسه با چرخش خلاف ­جهت آن­ها، منجربه نرخ اختلاط سریع­تر، دمای بیشینه بالاتر، نشر اکسیدنیتروژن بیشتر، و در عین حال موجب نشر مونوکسیدکربن کمتر می­شود. در کار حاضر، مشاهده می­شود که چرخش بهینه سوخت برابر با چرخش هوا و هم­جهت با آن است. در این حالت، میزان نشر اکسیدنیتروژن و مونوکسیدکربن، در مقایسه با طرح مرجع (که در آن سوخت بدون چرخش در نظرگرفته می­شود)، به­ترتیب، در حدود 2/15 درصد و 7/92 درصد کاهش می­ یابد.
 

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Numerical and Two-Dimensional Study of the Influences of the Swirl of Fuel on the Structure and the Environmental Features of a Gas Diffusion Flame

نویسندگان [English]

  • sina jamalzad
  • javad mahmoudimehr
Faculty of mechanical engineering, University of Guilan, Rasht, Iran
چکیده [English]

The positive influence of the swirl of reactants on the air-fuel mixing has been widely discussed in previous studies. However, they have been mostly focused on the swirl of air. The present work numerically investigates the influences of the swirl of fuel on the structure and the environmental features of a diffusion flame, while the swirl of air is kept constant. The results show that the increase of fuel swirl is associated with the increase of mixing rate, flame width, and flame peak temperature, and the decrease of CO emission and flame length. However, the trend of the variation of NO with fuel swirl number has a minimum somewhere in the middle. The results also illustrate that the co- swirl injection leads to higher mixing rate, peak temperature, emission of NO, and lower emission of CO, as compared to the counter-swirl injection. In this work, the optimum swirl of fuel is observed to have the same value and to be in the same direction as the swirl of air. In this case, the emissions of NO and CO are decreased by 15.2% and 92.7% as compared to the reference design (in which the fuel has no swirl), respectively

کلیدواژه‌ها [English]

  • Diffusion flame
  • Swirl
  • Emission of pollutants
  • Numerical modeling
  • optimization

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سوخت و احتراق
دوره 11، شماره 2
شهریور 1397
صفحه 31-50

فایل ها

سابقه مقاله

  • تاریخ دریافت: 01 بهمن 1396
  • تاریخ بازنگری: 11 اسفند 1396
  • تاریخ پذیرش: 04 فروردین 1397

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