مطالعه عددی تأثیرات سیستم افشانه و پدهای مرطوب در توزیع دمای گلخانه‌ای با سیستم تهویه فن

نوع مقاله : مقاله پژوهشی

نویسندگان

1 کارشناسی ارشد، گروه مهندسی مکانیک، دانشگاه قـم، قم، ایران

2 دانشیار، آزمایشگاه پژوهشی اتمسفر زمین و علوم فضایی، گروه مهندسی مکانیک، دانشگاه قـم، قم، ایران

چکیده

در این پژوهش رفتار جریان هوا، تغییرات دما و رطوبت در یک سالن گلخانه به کمک شبیه‌سازی عددی مطالعه شده است. به‌منظور رطوبت‌دهی به هوای در حال جریان داخل سالن گلخانه، دو میزان 04/0 و 08/0 کیلوگرم بر ثانیه آب با سه روش متفاوت به هوای عبوری به سالن گلخانه پاشش می‌شود در روش اول دو پد رطوبتی با مجموع سطح مقطع 15 متر مربع و در روش دوم دو افشانه در فاصله 5 و 30 متری از دیوار ابتدایی سالن و در ارتفاع 3 متری از کف گلخانه عملیات پاشش آب را انجام می‌دهند.  در روش سوم، بیست­وهفت افشانه عملیات پاشش قطرات آب را در مختصات مختلف به هوای عبوری گلخانه پاشش می­کنند. در سمت دیگر سالن گلخانه چهار فن با فشار منفی قرار دارند که جریان هوای تازه را در داخل سالن برقرار می­کنند. پس از اعتبار سنجی نتایج، از مدل توسعه‌یافته به منظور بررسی رفتار جریان و تاثیر انرژی نهان آب در تهویه گلخانه و رطوبت نسبی بهره گرفته شده‌است. با بررسی چهارده حالت تزریق رطوبت به هوای گلخانه، بهینه ترین حالت­ به ازای فشار خروجی فن برابر 50 پاسکال، با مدل 27 افشانه و نرخ جریان جرمی پاشش قطرات معادل 04/0 بدست آمده است. از طرفی اگر با معیار تغییرات دما و شرایط محیطی مناسب، طرح‌های اشاره شده مورد بررسی قرار گیرند، مشاهده می‌شود حالتی که از مدل پد رطوبت‌زنی با فشار فن 100 پاسکال و نرخ جریان جرمی پاشش قطرات 08/0 استفاده می‌شود، بهترین طرح برای رشد گیاهانی چون گلایل در محیط گلخانه مورد بررسی خواهد بود.

کلیدواژه‌ها

عنوان مقاله [English]

Numerical Study on the Effects of Spray System and Wet Pads on the Greenhouse Temperature Distribution by Fan Ventilation System

نویسندگان [English]

  • Sajjad Shahriari 1
  • Mohammad Kazem Moayyedi 2
1 Master's degree, Department of Mechanical Engineering, University of Qom, Qom, Iran
2 Associate Professor, Research Laboratory of Earth Atmosphere and Space Sciences, Department of Mechanical Engineering, University of Qom, Qom, Iran
چکیده [English]

In this research, the behavior of air flow, temperature, and humidity changes inside a greenhouse will be modeled using numerical simulation. To increase the humidity of the air flowing inside the greenhouse, water is sprayed into the air with two amounts of mass flow rate, through the greenhouse using three different methods. In the first method, two moisturized pads are used. In the second method, two water sprays at specific distances and a height of 3m from the greenhouse floor are used. In the third method, twenty-seven water droplet sprays in different locations are used. On the other side of the greenhouse hall, there are four fans with negative pressure, establishing fresh air flow inside the hall. The turbulence modeling approach was used to model the effects of turbulence in the flow field. After validating the numerical results, the outcome model has been used to study the flow behavior and the effect of the latent energy of water in greenhouse ventilation and relative humidity. By examining fourteen conditions of water droplet injection inside the greenhouse, the most suitable condition contains 50pa back pressure, 27 sprays, and a mass flow rate of droplet injection of 0.04 kg/s. On the other hand, if the mentioned plans are examined with the criterion of temperature changes and suitable environmental conditions. It can be seen that the outlet pressure of 100pa and mass flow rate of 0.08kg/s for water droplet injection in moisturized pad configuration, will be the best plan for the growth of plants such as Gladiolus in the greenhouse environment.

کلیدواژه‌ها [English]

  • Greenhouse Ventilation
  • computational Fluid Dynamics
  • Temperature Distribution
  • Humidity Ratio
  • Evaporation

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مکانیک سیالات و آیرودینامیک
دوره 13، شماره 1 - شماره پیاپی 33
بهار و تابستان 1403
مرداد 1403
صفحه 149-164

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سابقه مقاله

  • تاریخ دریافت: 16 فروردین 1403
  • تاریخ بازنگری: 12 خرداد 1403
  • تاریخ پذیرش: 02 تیر 1403
  • تاریخ انتشار: 01 مرداد 1403

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