بررسی اثر بازتاب دیواره‌های درونی مخزن فرابنفش بر غیرفعال‌سازی میکروارگانیزم موجود در آب با استفاده از دینامیک سیالات محاسباتی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 تربیت مدرس

2 دانشگاه تربیت مدرس

چکیده

بازتاب پرتو فرابنفش از دیواره‌های درونی، از مؤلفه‌های مؤثر بر افزایش کارآمدی مخازن فرابنفش، به شمار می‌آید. در این مطالعه، به ارزیابی میزان تأثیرگذاری مقادیر مختلفی از بازتاب دیواره‌های درونی مخزن، بر عملکرد مخزن فرابنفش چندلامپی، با استفاده از شاخص‌هایی چون دوز دریافتی ذرات و مقادیر لگاریتم غیرفعال‌سازی میکروارگانیزم‌های ام.اس.دو و باسیلوس سابتیلیس، پرداخته شده است. شبیه‌سازی میدان جریان با استفاده از مدل کا-امگا-اس.اس.تی صورت پذیرفته است و برای محاسبات میدان تابش، مدل جهت‌های مجزا در نظر گرفته شده است. مقادیر بازتاب دیواره در بازه‌ای از صفر (بدون بازتاب) تا صد (بازتاب ایده‌آل) درصد قرار داده شده است. در این گستره از بازتاب، برای دیواره‌ مخزن با پوشش آلومینیوم، بازتاب 5/80 درصد و برای دیواره‌ فولادی، بازتاب 1/26 درصد در نظر گرفته شد. میزان تأثیرگذاری بازتاب در دو مقدار ضریب گذردهی 7/87 و 5/78 درصد، محاسبه شد. برای ضریب گذردهی 5/78 درصد، مقدار تغییر دوز دریافتی و مقادیر لگاریتم غیرفعال‌سازی با افزایش درصد بازتاب، بسیار اندک بود و روند محسوس افزایش این مقادیر برای ضریب گذردهی 7/87 درصد، با افزایش درصد بازتاب، به چشم می‌خورد. روند تغییر نتایج مربوط به دو دبی متفاوت در ضریب گذردهی 5/78 مشابه بود. نحوه‌ی عملکرد مخزن در دو توان متفاوت در ضریب گذردهی 5/78 درصد بررسی شد که در توان بالاتر، میزان اثرگذاری روند افزایشی بازتاب، بیش‌تر مشاهده شد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

The Effect of Inner Walls Reflection on Microorganisms Inactivation in Water Ultraviolet Reactor using computational fluid dynamics

نویسندگان [English]

  • Ghassem Heidarinejad 1
  • nasrin bozorgmehr 2
  • mohamad safarzadeh 1
2 Tarbiat modarres university
چکیده [English]

The inner walls reflection of ultraviolet radiation is one of the effective components of the ultraviolet reactor efficiency. In this study, the effect of inner walls reflection of the reactor on the performance of the multi-lamp ultraviolet reactor has been evaluated using ultraviolet dose distribution and log inactivation values of MS2 and Bacillus subtilis microorganisms. The simulation of the flow field is performed using the SST k-ω model and the discrete ordinates model for radiation. The wall reflectivity is in the range of zero (no reflection) to 100 (ideal reflection) percent. In this range of reflections, for the reactor walls with aluminum cover, the reflectivity of 80.5% and 26.1% for the steel wall and ultraviolet transmittance of 87.7% and 78.5% were calculated. For ultraviolet transmittance of 78.5%, the received dose and log inactivation change with increasing reflectivity were very low but for ultraviolet transmittance of 87.7%, there is a tangible increase in these values and the results variation trend for two different flow rate was similar in ultraviolet transmittance of 78.5%. The performance of the reactor was investigated in two different lamp powers and ultraviolet transmittance of 78.5%, which is related to the higher power, the reflectivity effect has become more apparent.

کلیدواژه‌ها [English]

  • Ultraviolet reactor
  • computational fluid dynamics
  • Discrete ordinates model
  • reflection
  • Bacillus subtilis and MS2 microorganism
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