بررسی اثر خصوصیات حرارتی بتن بر عملکرد حرارتی شمع‌های زمین‌گرمایی با در نظر گرفتن اثر همرفت ترکیبی

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی عمران، دانشگاه صنعتی شریف، تهران، ایران.

چکیده

شمع‌های زمین‌گرمایی سازه‌هایی با دو عملکرد سازه‌ای و حرارتی هستند که به عنوان یکی از روش‌های جدید استفاده از منابع انرژی‌های تجدیدپذیر زمین‌گرمایی و گامی موثر جهت توسعه‌ی پایدار مورد استفاده قرار می‌گیرند. عملکرد حرارتی این شمع‌ها تحت تاثیر شرایط محیطی و پارامترهای هیدرولیکی و حرارتی متعددی قرار می‌گیرد. در این تحقیق با استفاده از یک مدل‌سازی عددی اجزای محدود، اثر پارامترهای حرارتی بتن بر عملکرد حرارتی یک شمع زمین‌گرمایی با در نظر گرفتن اثر زمین لایه‌ای اشباع، جریان آب زیرزمینی و به دنبال آن، اثرات انتقال حرارت همرفت طبیعی و اجباری مورد بررسی قرار می‌گیرد و به این سوال پاسخ داده می‌شود که در چه نوع بتن مصرفی، شمع‌های زمین‌گرمایی عملکرد حرارتی بهتری دارند و در نهایت مقایسه‌ی کمی میان اثر این پارامترها بر توان تبادل حرارتی شمع‌انرژی به کمک یک ضریب حساسیت در تحلیل حساسیت انجام می‌شود. نتایج بدست‌آمده نشان می‌دهد ضریب‌ هدایت حرارتی بتن با ضریب حساسیت 0/2607 بیشترین اثر و برعکس پارامترهای ظرفیت گرمایی ویژه بتن و چگالی جرمی کمترین تاثیر را بر بهبود عملکرد حرارتی این سیستم دارند و بهینه‌سازی این پارامترها با اولویت ضریب رسانایی حرارتی بتن می‌تواند به منظور انتخاب طرح اختلاط مناسب جهت اجرای این‌ نوع شمع‌ها از دیدگاه عملکرد حرارتی مورد ارزیابی قرار بگیرد تا طرح نهایی بیشترین بازدهی را فراهم آورد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation of the Effects of Concrete’s Thermal Characteristics on the Thermal Performance of Geothermal Piles Considering Mixed Convection

نویسندگان [English]

  • Farhang Azizi Zade
  • Mohammad Mehdi Ahmadi
Geotechnical Engineering Group, Department of Civil Engineering, Sharif University of Technology, Tehran, Iran
چکیده [English]

Geothermal piles are multifunctional structures that simultaneously serve structural and thermal purposes and are considered an emerging approach for utilizing renewable geothermal energy, contributing effectively to sustainable development. The thermal performance of these piles is influenced by environmental conditions as well as various hydraulic and thermal parameters. In this study, a finite element numerical model is employed to investigate the influence of concrete thermal properties on the thermal performance of a geothermal pile, taking into account the effects of a saturated layered soil, groundwater flow, and the associated natural and forced convective heat transfer mechanisms. The study addresses the question of which type of concrete provides superior thermal performance for geothermal piles. Furthermore, a quantitative comparison of the influence of these parameters on the heat exchange capacity of the energy pile is conducted using a sensitivity analysis approach. The results indicate that the thermal conductivity of concrete, with a sensitivity coefficient of 0.2607, has the most significant impact on thermal performance, whereas the specific heat capacity and mass density of concrete exhibit the least influence. Consequently, optimizing concrete thermal properties, particularly prioritizing thermal conductivity, can be considered an effective criterion for selecting an appropriate concrete mix design for geothermal piles from a thermal performance perspective, ensuring maximum system efficiency.

کلیدواژه‌ها [English]

  • Geothermal Piles
  • Natural Convection
  • Forced Convection
  • Heat Exchange Capacity
  • Numerical Modeling
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