بهبود مبادله‌کن‌های حرارتی پوسته ‌لوله با بافل‌های مارپیچ و قطاعی حفره‌دار

نوع مقاله : مقاله پژوهشی (توسعه ای)

نویسندگان

1 مدرس گروه مهندسی مکانیک، دانشگاه فنی حرفه‌ای، تهران، ایران.

2 استادیار دانشگاه فنی حرفه‌ای، دانشکده فنی مهندسی، دانشگاه فنی حرفه‌ای، تهران، ایران.

3 دانشجوی دکتری عمران، دانشکده مهندسی، دانشگاه آزاد خرم آباد، لرستان، ایران.

4 کارشناسی مهندسی مکانیک، گروه مکانیک، دانشگاه فنی حرفه‌ای، تهران، ایران.

10.48301/kssa.2023.365871.2317

چکیده

در این تحقیق رفتار هیدرولیکی حرارتی جریان سیال در مبادله­کن حرارتی پوسته ‌لوله با بافل­های جدید حفره­دار قطاعی، حفره­دار  مارپیچ با ساختار­های پایه (قطاعی و مارپیچ ساده) به‌صورت عددی بررسی می­شوند. با مقایسۀ پارامترهای ارزیابی مانند انتقال حرارت، افت فشار، نسبت انتقال حرارت به فشار، و ضریب ارزیابی عملکرد (EEC) نقش بافل‌های ارائه‌شده با ساختار پایه (بافل قطاعی، بافل مارپیچ یک‌طرفه) مقایسه می­شود، بر اساس نتایج به‌دست‌آمده، بافل مارپیچ پیوسته حفره‌دار نسبت به بافل مارپیچ ساده 46/22 درصد و بافل قطاعی حفره‌دار نسبت به بافل قطاعی ساده 76/19 درصد افت فشار را کاهش می­دهد. وجود حفره­ها باعث ایجاد یک مسیر جدید جریان  در طول دسته لوله­ ها می­شود. در یک ارزیابی جامع‌تر با مقایسۀ­ ضریب ارزیابی عملکرد ساختارهای حفره‌دار بافل مارپیچ و قطاعی به ترتیب افزایش 3/18 و 17/11 درصد نسبت به ساختارهای پایه ارائه دادند.  این ایده با تغییر الگوی جریان از مارپیچ به مارپیچ-طولی و از زیگزاگی به زیگزاگ-طولی توزیع جریان در سمت پوسته را یکنواخت‌تر می­کند در واقع این مدل جریان باعث کاهش نواحی مستعد رسوب (نواحی مرده) و هزینه‌های نگهداری و بهبود عملکرد سیستم  می‌گردد. با این وجود، ساختار جدید حفره­دار می‌تواند جایگزین بافل­های قطاعی مرسوم برای صرفه‌جویی در انرژی در مدت‌ زمان طولانی باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Improvement of Shell and Tube Heat Exchangers with Pore Structures of Helical and Segmental Baffles

نویسندگان [English]

  • Hamed Uosofvand 1
  • Reza Moradi 2
  • Ebrahim Rezaee habil 3
  • Mohammadreza Ezatiortakand 4
1 Lecturer, Department of Mechanical Engineering, Technical and Vocational University (TVU), Tehran, Iran.
2 Assistant professor, Department of Mechanical Engineering, Faculty of Enghelabe Eslami Branch, Technical and Vocational University (TVU), Tehran, Iran.
3 PhD student in Civil Engineering, Faculty of Engineering, Islamic Azad University of Khorramabad, Lorestan, Iran.
4 BSc, Department of Mechanical Engineering, Technical and Vocational University (TVU), Tehran, Iran.
چکیده [English]

In this research, the thermal-hydraulic behaviour of fluid in the shell and tube heat exchanger with new segmental perforated baffles and hollow spiral baffles with basic structures (simple segmental and simple helical) were investigated. By using evaluation parameters such as heat transfer, pressure drop, ratio of heat transfer to pressure drop, and efficiency evaluation coefficient (EEC), the effect of the proposed baffles was compared with the basic structure (segmental baffle, single pass helical baffle). Based on the obtained results, the perforated continuous helical baffle reduced the pressure drop by 22.46% compared to the simple helical baffle and the perforated segmental baffle reduced the pressure drop by 19.76% compared to the simple segmental baffle. In a more comprehensive evaluation, the efficiency evaluation coefficient of pore helical and segmental baffle structures showed an increase of 18.3 and 11.17 per cent, respectively compared to the basic configuration. The concept of changing the flow pattern from helix to helix-longitudinal and from zigzag to zigzag-longitudinal made the flow distribution on the shell side more uniform. These conditions reduced areas prone to sedimentation (dead areas) and maintenance costs, and improved system performance. In addition, this new structure can replace conventional segmental baffles to save energy in the long term.

کلیدواژه‌ها [English]

  • Shell and Tube Exchanger
  • Pressure Drop
  • Heat Transfer
  • Segmental Baffle
  • Helical Baffle
  • Pore Baffle
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