بررسی تأثیر تخلخل بر عملکرد ترموهیدرولیکی یک کلکتور هواگرم خورشیدی به-همراه موانع متخلخل
محورهای موضوعی :
انرژی های تجدید پذیر
امین قلعه نوئی
1
,
مجید سبزپوشانی
2
1 - دانشجوی دکترا، گروه مهندسی مکانیک، دانشگاه کاشان، کاشان، ایران.
2 - دانشیار گروه مهندسی مکانیک، دانشگاه کاشان، کاشان، ایران. *(مسوول مکاتبات)
تاریخ دریافت : 1400/01/21
تاریخ پذیرش : 1401/06/09
تاریخ انتشار : 1402/05/01
کلید واژه:
افت فشار,
راندمان گرمایی,
هواگرم‌کن خورشیدی,
موانع متخلخل,
راندمان مؤثر,
چکیده مقاله :
زمینه و هدف: به دلیل خواص فیزیکی-حرارتی نامطلوب هوا، کلکتور‌های هواگرم از راندمان حرارتی بالایی برخوردار نیستند و نیاز است تا به کمک شیوه‌های مختلف راندمان آنها را بهبود بخشید. در این پژوهش به صورت تجربی تأثیر استفاده از موانع متخلخل بر روی عملکرد گرمایی و هیدرولیکی کلکتور مورد بررسی قرار گرفت و با عملکرد یک کلکتور ساده مقایسه شد.
روش بررسی: یک دستگاه کلکتور هواگرم خورشیدی طراحی و ساخته شد و تحت شرایط محیطی شهرستان آبادان در استان خوزستان مورد آزمایش قرار گرفت. سه نوع مختلف موانع متخلخل با سه اندازه سوراخ (3، 4 و 5 سانتی متر) بر روی صفحه جاذب کارگذاشته شد. پارامترهای اندازه گیری شده شامل دمای هوای ورودی و خروجی، دمای صفحه جاذب، افت فشار و تابش خورشید می شود. اندازه گیری ها در ماه آذر برای دو مقدار مختلف جریان جرمی هوا ( 0218/0 و 0364/0 کیلوگرم بر ثانیه) انجام شد.
یافته‌ها: مشخص شد که استفاده از موانع متخلخل باعث افزایش اختلاف دما بین ورودی و خروجی از کلکتور و راندمان سیستم در مقایسه با یک کلکتور ساده می شود. همچنین مشخص شد که در تمامی موارد با افزایش دبی جرمی، راندمان گرمایی و مؤثر سیستم افزایش و اختلاف دمای بین هوای ورودی و خروجی کاهش می یابد. اختلاف دما در بهترین حالت (موانع با سوراخ های cm 3) برای هر دو دبی 2 برابر نسبت به کلکتور ساده افزایش داشت. همچنین بیشترین مقدار میانگین راندمان گرمایی برای دو دبی 68% و 83% و میانگین راندمان مؤثر 4/28% و 1/%34 به دست آمد.
بحث و نتیجه گیری: با کاهش ابعاد سوراخ های درون موانع، نرخ انتقال حرارت و راندمان گرمایی کلکتور به واسطه افزایش اغتشاش جریان افزایش می یابد. این امر موجب بالا رفتن افت فشار نیز می گردد اما همچنان تأثیر مثبت افزایش اختلاف دما بر تأثیر منفی افزایش افت فشار غلبه می کند و در نهایت مشخص می شود نسبت مستقیمی بین زیاد شدن راندمان مؤثر با کم شدن اندازه قطر سوراخ ها وجود دارد.
چکیده انگلیسی:
Background and Objective: Due to undesirable thermo-physical properties of the air, the solar air collectors do not benefit from the high thermal efficiency and need to be improved with the help of different methods. In this study, the effects of using various obstacles on the thermohydraulic performance of a collectors were examined experimentally and compared to the performance of a simple collector.
Material and Methodology: A solar air collector was designed, built and tested under the environmental conditions of Abadan city in Khuzestan province. Three different perforated obstacles with three hole sizes (3, 4 and 5 cm) were placed on the absorber plate. Measured parameters include the temperature of inlet and outlet air, absorber plate, pressure drop and solar radiation. Measurements were made for two different air flux (0.0218 and 0.0364 kg/s).
Findings: It has become clear that using various perforated obstacles increases the temperature difference between inlet and outlet air and subsequently their efficiencies compared to a simple conventional collector. It was also noted that in all cases, the increase in mass flowrate causes increasing the effective and thermal efficiency of system and decreasing the temperature difference between inlet and outlet air. Temperature difference in the best case (perforated obstacles with 3 cm holes) for each of the two flowrates increases twice compared to the simple collector. Also, the highest amount of average efficiency for two flowrates is 68% and 83% and the average effective efficiency is 28.4% and 34.1%.
Discussion and Conclusion: With the reduction of sizes of the holes in the perforated obstacles, the rate of heat transfer and subsequently the thermal efficiency of the collector will increase due to increasing the turbulence of the flow. This causes the pressure drop to rise up as well but also has a positive effect of increasing the temperature difference which dominates the negative effect of the pressure drop and eventually it becomes clear that there is a direct relation between increasing the effective efficiency with reducing the size of the holes.
منابع و مأخذ:
http://www.mimt.gov.ir/
Ahmed-Zaid, A., Messaoudi, H., Abenne, A., Le Ray, M., Desmons, J. Y., Abed, B., 1999. Experimental study of thermal performance improvement of a solar air flat plate collector through the use of obstacles: application for the drying of yellow onion. Int. J. Energy Res., Vol. 23, pp. 1083-199.
Abene, A., Dubois, V., Le Ray, M., Ouagued, A., 2004. Study of a solar air flat plate collector: use of obstacles and application for the drying of grape. Journal of Food Engineering, Vol. 65, pp. 15–22.
Handoyo, E. A., Ichsani, D., Prabowo, Sutardi, 2016. Numerical studies on the effect of delta-shaped obstacles’ spacing on the heat transfer and pressure drop in v-corrugated channel of solar air heater, Solar Energy, Vol. 131, pp. 47-60.
Kulkarni, K., Afzal, A., Kim, K.Y., 2015. Multi-objective optimization of solar air heater with obstacles on absorber plate. Solar Energy, Vol. 114, pp. 364–377.
Alam, T., Kim, M.H., 2016. Numerical study on thermal hydraulic performance improvement in solar air heater duct with semi ellipse shaped obstacles. Energy, Vol. 112, pp. 588-598.
Kumar, A., Kumar, R., Maithani, R., Chauhan, R., Sethi, M., Kumari, A., Kumar, S., Kumar, S., 2017. Correlation development for Nusselt number and friction factor of a multiple type V-pattern dimpled obstacles solar air passage. Renewable Energy, Vol. 109, pp. 461-479.
Nadda, R., Kumar, A., Maithani, R., 2017. Developing heat transfer and friction loss in an impingement jets solar air heater with multiple arc protrusion obstacles. Solar Energy, Vol. 158, pp. 117–131.
Bensaci, C., Moummi, A., Flor, F., Jara, E., Rincon-Casado, A., Ruiz-Pardo, A., 2020. Numerical and experimental study of the heat transfer and hydraulic performance of solar air heaters with different baffle positions. Renewable Energy, Vol. 155, pp. 1231-1244.
Luan, N.T., Phu, N.M., 2020. Thermohydraulic correlations and exergy analysis of a solar air heater duct with inclined baffles. Case Studies in Thermal Engineering, Vol. 21, 100672.
Sharma, N.Y., Madhwesh, N., Karanth, K.V., 2019. The Effect of Flow Obstacles of Different Shapes for Generating Turbulent Flow for Improved Performance of the Solar Air Heater. Procedia Manufacturing Vol. 35, pp. 1096-1101.
Saravanakumar, P.T., Somasundaram, D., Matheswaran, M.M., 2019. Thermal and thermo-hydraulic analysis of arc shaped rib roughened solar air heater integrated with fins and baffles. Solar Energy, Vol. 180, pp. 360-371.
Saravanakumar, P.T., Somasundaram, D., Matheswaran, M.M., 2020. Exergetic investigation and optimization of arc shaped rib roughened solar air heater integrated with fins and baffles. Applied Thermal Engineering, Vol. 175, 115316.
Kumar, A. and Layek, A., 2021. Energetic and exergetic based performance evaluation of solar air heater having winglet type roughneѕѕ on absorber surface. Solar Energy Materials and Solar Cells, Vol. 230, 11147.
Saravanan, A., Murugan, M., Sreenivasa Reddy, M., Ranjit, P.S., Elumalai, P.V., Pramad Kumar, Rama Sree, S., 2021. Thermo-hydraulic performance of a solar air heater with staggered C-shape finned absorber plate. International Journal of Thermal Sciences, Vol. 168, 107068.
Dong. Z., Liu. P., Xiao. H., Liu, Z., Liu. W., 2021. A study on hear transfer enhancement for solar air heaters with ripple surface. Renewable Energy, Vol. 172, pp. 477-487.
Sureandhar, G., Srinivasan, G., Muthkumar, P., Senthilmurugan, S., 2021. Performance Analysis of arc rib fin embedded in a solar air heater. Thermal Science and Engineering Progress, Vol. 23, 100891.
KhoshAkhlagh, F., Molaei Pardeh, A., Abadijoo, M.M., 2014. Analysis and zoning of climatic potentials of Khuzestan province for the use of solar energy. Nivar, Vol. 92. (In Persian)
K. Mohammadi, M. Sabzpooshani, Comprehensive performance evaluation and parametric studies of single pass solar air heater with fins and baffles attached over the absorber plate, Energy, Vol. 57, pp. 741-750, 2013.
MK. Gupta, SC. Kaushik. Performance evaluation of solar air heater for various artificial roughness geometries based on energy, effective and exergy efficiencies. Renew Energy, Vol. 34, pp. 465-476, 2009.
Ansari, M. and Bazargan, M., 2018. Optimization of Flat Plate Solar Air Heaters with Ribbed Surfaces. Applied Thermal Engineering, Vol. 136: pp. 356-363.
_||_
http://www.mimt.gov.ir/
Ahmed-Zaid, A., Messaoudi, H., Abenne, A., Le Ray, M., Desmons, J. Y., Abed, B., 1999. Experimental study of thermal performance improvement of a solar air flat plate collector through the use of obstacles: application for the drying of yellow onion. Int. J. Energy Res., Vol. 23, pp. 1083-199.
Abene, A., Dubois, V., Le Ray, M., Ouagued, A., 2004. Study of a solar air flat plate collector: use of obstacles and application for the drying of grape. Journal of Food Engineering, Vol. 65, pp. 15–22.
Handoyo, E. A., Ichsani, D., Prabowo, Sutardi, 2016. Numerical studies on the effect of delta-shaped obstacles’ spacing on the heat transfer and pressure drop in v-corrugated channel of solar air heater, Solar Energy, Vol. 131, pp. 47-60.
Kulkarni, K., Afzal, A., Kim, K.Y., 2015. Multi-objective optimization of solar air heater with obstacles on absorber plate. Solar Energy, Vol. 114, pp. 364–377.
Alam, T., Kim, M.H., 2016. Numerical study on thermal hydraulic performance improvement in solar air heater duct with semi ellipse shaped obstacles. Energy, Vol. 112, pp. 588-598.
Kumar, A., Kumar, R., Maithani, R., Chauhan, R., Sethi, M., Kumari, A., Kumar, S., Kumar, S., 2017. Correlation development for Nusselt number and friction factor of a multiple type V-pattern dimpled obstacles solar air passage. Renewable Energy, Vol. 109, pp. 461-479.
Nadda, R., Kumar, A., Maithani, R., 2017. Developing heat transfer and friction loss in an impingement jets solar air heater with multiple arc protrusion obstacles. Solar Energy, Vol. 158, pp. 117–131.
Bensaci, C., Moummi, A., Flor, F., Jara, E., Rincon-Casado, A., Ruiz-Pardo, A., 2020. Numerical and experimental study of the heat transfer and hydraulic performance of solar air heaters with different baffle positions. Renewable Energy, Vol. 155, pp. 1231-1244.
Luan, N.T., Phu, N.M., 2020. Thermohydraulic correlations and exergy analysis of a solar air heater duct with inclined baffles. Case Studies in Thermal Engineering, Vol. 21, 100672.
Sharma, N.Y., Madhwesh, N., Karanth, K.V., 2019. The Effect of Flow Obstacles of Different Shapes for Generating Turbulent Flow for Improved Performance of the Solar Air Heater. Procedia Manufacturing Vol. 35, pp. 1096-1101.
Saravanakumar, P.T., Somasundaram, D., Matheswaran, M.M., 2019. Thermal and thermo-hydraulic analysis of arc shaped rib roughened solar air heater integrated with fins and baffles. Solar Energy, Vol. 180, pp. 360-371.
Saravanakumar, P.T., Somasundaram, D., Matheswaran, M.M., 2020. Exergetic investigation and optimization of arc shaped rib roughened solar air heater integrated with fins and baffles. Applied Thermal Engineering, Vol. 175, 115316.
Kumar, A. and Layek, A., 2021. Energetic and exergetic based performance evaluation of solar air heater having winglet type roughneѕѕ on absorber surface. Solar Energy Materials and Solar Cells, Vol. 230, 11147.
Saravanan, A., Murugan, M., Sreenivasa Reddy, M., Ranjit, P.S., Elumalai, P.V., Pramad Kumar, Rama Sree, S., 2021. Thermo-hydraulic performance of a solar air heater with staggered C-shape finned absorber plate. International Journal of Thermal Sciences, Vol. 168, 107068.
Dong. Z., Liu. P., Xiao. H., Liu, Z., Liu. W., 2021. A study on hear transfer enhancement for solar air heaters with ripple surface. Renewable Energy, Vol. 172, pp. 477-487.
Sureandhar, G., Srinivasan, G., Muthkumar, P., Senthilmurugan, S., 2021. Performance Analysis of arc rib fin embedded in a solar air heater. Thermal Science and Engineering Progress, Vol. 23, 100891.
KhoshAkhlagh, F., Molaei Pardeh, A., Abadijoo, M.M., 2014. Analysis and zoning of climatic potentials of Khuzestan province for the use of solar energy. Nivar, Vol. 92. (In Persian)
K. Mohammadi, M. Sabzpooshani, Comprehensive performance evaluation and parametric studies of single pass solar air heater with fins and baffles attached over the absorber plate, Energy, Vol. 57, pp. 741-750, 2013.
MK. Gupta, SC. Kaushik. Performance evaluation of solar air heater for various artificial roughness geometries based on energy, effective and exergy efficiencies. Renew Energy, Vol. 34, pp. 465-476, 2009.
Ansari, M. and Bazargan, M., 2018. Optimization of Flat Plate Solar Air Heaters with Ribbed Surfaces. Applied Thermal Engineering, Vol. 136: pp. 356-363.
