نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار، دانشکده مهندسی معماری و شهرسازی، دانشگاه تربیت دبیر شهید رجایی، تهران،ایران.

2 کارشناسی ارشد مهندسی معماری ، موسسه آموزش عالی جهاد دانشگاهی ، اهواز، ایران.

چکیده

امروزه استفاده از انرژی خورشیدی به عنوان یک منبع ارزان و بی‌پایان در صنعت ساختمان، به یکی از دغدغه‌های بزرگ محققین در سراسر جهان بدل شده است. یکی از روش‌های مهار انرژی خورشیدی، استفاده از دودکش خورشیدی در ساختمان است. هدف از این پژوهش، یافتن الگویی مناسب جهت طراحی دودکش‌های خورشیدی برای اتاق‌های جنوبی (آفتاب‌گیر) خانه‌های شهر اهواز (اقلیم گرم و نیمه ‌مرطوب ) است، به نحوی که با بهره‌گیری مؤثر از انرژی خورشیدی، موجب بهبود آسایش حرارتی ساکنین گردد. این امر کاهش محسوس مصرف انرژی را به همراه خواهد داشت. روش تحقیق در این پژوهش، یک روش ترکیبی است که راهبردهای تحقیق تجربی، شبیه‌سازی و پژوهش موردی را درگیر می‌نماید. بر این اساس، پس از مشاهدات تجربی در وضعیت اتاق‌های جنوبی خانه‌های آپارتمانی در اهواز، یک الگوی کلی برای اتاق پیشنهاد گردید و مدل‌های مختلف دودکش خورشیدی متناسب با الگوی پیشنهادی شبیه‌سازی شدند. لازم  به ذکر است که شبیه‌سازی‌ها با نرم‌افزار انرژی پلاس و پس از اثبات روایی و پایایی انجام شدند. کلیه شبیه‌سازی‌ها برای یک آپارتمان 4 طبقه با اتاق‌های مشابه جنوبی و یک دودکش خورشیدی مشترک، انجام پذیرفتند و نتایج در یک دوره آزمون که طبق نمودارهای سالانه آسایش برقرار است، مقایسه شده‌اند. بررسی‌ها نشان دادند که دودکش‌های خورشیدی بهینه با ابعاد و ضوابط پیشنهادی در این مقاله، تا حد بسیار زیادی موجب بهبود تهویه طبیعی و ارتقای آسایش حرارتی ساکنین داخل اتاق شده و متعاقباً صرفه‌جویی بسیار زیادی در مصرف انرژی را به دنبال خواهد داشت. بر اساس نتایج این مقاله دودکش با ابعاد 2×1.16×11.60 متر(مدل 2) ،برای شهر اهواز پیشنهاد می‌شود. البته طی این آزمون مدل‌های دیگر آزمایش شده است که بر اساس شرایط این ابعاد بهینه پیشنهاد گردیده است.

چکیده تصویری

بررسی عملکرد اقلیمی دودکش‌های خورشیدی برای خانه‌های اهواز در اتاق‌های آفتابگیر جنوبی

تازه های تحقیق

- ابعاد بهینه‌ی دودکش خورشیدی در اتاق‌های رو به جنوب شهر اهواز.
- استفاده از نرم‌افزارهای مدل‌سازی و شبیه‌سازی (اکوتکت و انرژیِ پلاس).
- ایجاد آسایش حرارتی در ماه‌های: اسفند، فروردین، اردیبهشت، خرداد، مهر و آبان، آذر.

کلیدواژه‌ها

عنوان مقاله [English]

Improving the climate performance of solar chimneys for Ahvaz houses in south equator-facing rooms

نویسندگان [English]

  • Omid Rahaei 1
  • Zeynab Poorsayahi 2

1 Assistant Professor, School of Architecture and Urban Design, Shahid Rajaei Teacher training University, Tehran, Iran.

2 M.A. in Architecture, Jahad University of Khoozestan, Ahvaz, Iran.

چکیده [English]

Extended Abstract
Background and Objectives: Today, the use of solar energy as a cheap and renewable source in the construction industry has become one of the major concerns worldwide. One way to harness solar power is to use a solar chimney in the building. The solar chimney acts as a passive natural ventilation system or as a thermal insulator based on pressure displacement caused by air pressure fluctuations inside the chimney shaft. This chimney usually consists of glass, duct, and absorber surface. The air in the chimney is heated by solar energy and moves upwards due to the chimney effect, which can increase the natural ventilation in the adjacent spaces. In hot and semi-humid climate buildings, windows are usually closed to prevent direct sunlight. Therefore, solar chimneys can establish airflow and supply fresh air indoors. The ventilation process in buildings of Ahvaz city, due to particular climatic conditions (hot and semi-humid), is essential. Also, air conditioning is costly, consuming a great amount of energy. Therefore, this study aims to find appropriate criteria for the effective design and implementation of solar chimneys in houses in Ahvaz to establish an effective flow inside the air duct in seasons requiring thermal comfort conditions and to create effective ventilation inside the interior spaces through stack effect. This study aims to find a suitable model for designing solar chimneys for the southern (equator-facing) rooms of houses in Ahvaz city (hot and semi-humid climate) to improve the thermal comfort of residents by using solar energy effectively and reducing energy consumption significantly.
Methods: This research combines different methods due to its interdisciplinary nature. Research variables and models were identified in the first stage using an experimental strategy. The physical structure of the room and the solar chimney were studied as independent variables and the room interior temperature as a dependent variable in this study. A digital thermometer was used for experimental thermometry tests in the case sample. The statistical population selected in this study includes southern rooms in apartments in Ahvaz. The statistical population is a small room as a random case sample. In the next step, solar chimneys were modeled in Ecotect software, and a simulation method was used to analyze the data and intervene in the architecture. The simulations were performed using Energy Plus software version 8.7.0 and the existing weather data (regarding the literature). Also, the simulations were calculated linearly and thermodynamically by TARP thermal model method prepared by Walton (1983) in the software. The Fangar comfort model, PMV index, and PPD were used in the next step of data analysis. Finally, the experimental data were compared to the simulated data to investigate research validity and reliability. Thus, the research method is a combination of experimental strategies, simulation, and a case study. Bibliographic studies, field observations, field measurements, and simulations were used as research tools.
Findings: In this study, four different models of solar chimneys on a specific day were studied to investigate the effect of geometry on the model discharge. Also, the thermal comfort (of the first model) was studied on a specific day of the year. (The reason for choosing this model is to investigate the chimney effect on the whole space). The simulation data of the first model with dimensions of 1 × 1.16 × 11.60 showed that the thermal comfort level in this type of solar chimney is close to the allowable limit in March, April, May, June, October, and, November, December. According to the diagrams, using this type of chimney is unsuitable in July, August, and September, so this model is not approved. On May 1st, the effect of the number of floors on the thermal performance of the first model was investigated. The results showed that the solar chimney discharge does not always lead to acceptable thermal comfort conditions. Also, four specific geometries were compared regarding the effect of geometry on the solar chimney discharge. According to findings, the solar chimney height was more effective in determining the maximum and average solar chimney flow than its width. According to the results, the third model has a more powerful airflow but drops to zero at certain hours and has no night ventilation. So, having a chimney with a maximum flow is not necessarily appropriate. The best model, according to the comparative method, is the second model with dimensions (2 × 1.16 × 11.60), and then the third model with dimensions (1 × 1.16 × 23.20), with strong airflow powers.
Conclusion: By examining the airflow and thermal comfort conditions in solar chimneys, it was determined that the airflow could create suitable comfort conditions in the building annually. Therefore, the solar chimney with dimensions of 2 × 1.16 × 11.60 (model 2) is suitable for equator-facing rooms with dimensions of 3.5 × 5.9 meters in Ahvaz and can provide comfort levels in the mentioned months. According to the results, this system is needed all year round. When there are no comfort conditions, it is recommended to benefit from mechanical systems, ventilation and air conditioning, green space, and natural ventilation systems for comfort conditions.

کلیدواژه‌ها [English]

  • Solar Chimney
  • Climate
  • Thermal Comfort
  • Ahvaz Houses
  • Energy Plus

این مقاله برگرفته از پایان‌نامه ارشد نویسنده دوم با عنوان «بررسی عملکرد اقلیمی دودکش‌های خورشیدی برای خانه‌های اهواز در اتاق‌های آفتابگیر جنوبی» می‌باشد که به راهنمایی نویسنده اول در دانشگاه جهاد دانشگاهی خوزستان انجام گرفته است.

This article is derived from the second author`s Master thesis entitled “Improving the Climate Performance of Solar Chimneys for Ahwaz houses in South Sunshiny Rooms”, supervised by the first author, at Jahad University of Khoozestan.

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