تأثیر جریان بازگشتی هوا بر راندمان خشک‌کن خورشیدی غیرمستقیم با کلکتور خلأ مجهز به مادۀ تغییرفازدهنده و مبدل حرارتی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه مهندسی مکانیک، دانشگاه جیرفت، جیرفت، ایران

2 گروه مهندسی بیوسیستم، دانشکده کشاورزی، دانشگاه کردستان، سنندج، ایران

چکیده

 
در فرایند خشک‌کردن محصولات کشاورزی، وجود میزان زیاد رطوبت اولیه سبب افزایش مصرف انرژی می‌گردد. به‌منظور کاهش این مصرف، بهره‌گیری از سامانه‌های خورشیدی به‌صورت مستقل یا ترکیبی با دیگر منابع حرارتی، روشی متداول محسوب می‌شود. بااین‌حال، یکی از عوامل کاهش کارایی در خشک‌کن‌ها، اتلاف انرژی گرمایی در سیستم‌های دارای جریان باز است. به‌کارگیری جریان هوای بازگشتی در ورودی خشک‌کن می‌تواند موجب بهبود راندمان حرارتی و کاهش زمان خشک‌ شدن محصول گردد. در این پژوهش، یک خشک‌کن خورشیدی غیرمستقیم از نوع کابینتی که به یک کلکتور خورشیدی لوله خلأ و یک مبدل حرارتی مجهز به ماده تغییرفازدهنده (PCM) مجهز است، مورد بررسی قرارگرفت. تأثیر درصدهای مختلف جریان بازگشتی (۰، ۲۵، ۵۰ و ۷۰ درصد) بر مصرف انرژی ویژه (SEC)، بازده کلی فرایند خشک‌کردن و راندمان کلکتور خورشیدی در یک خشک‌کن خورشیدی غیرمستقیم از نوع کابینتی مورد بررسی قرار گرفته است. همچنین به‌منظور تحلیل رفتار جریان و تغییرات دمایی در داخل خشک‌کن، شبیه‌سازی سه‌بعدی با روش دینامیک سیالات محاسباتی (CFD) انجام گردید. نتایج عددی نشان داد که حالت 50 درصد جریان بازگشتی، بهینه‌ترین وضعیت است؛ به‌طوری‌که زمان خشک‌سازی را از 910 ثانیه (در حالت صفر) به 545 ثانیه کاهش داده و کمترین مصرف انرژی ویژه معادل 62/10 مگاژول بر کیلوگرم را با استفاده از ظرفیت حرارتی نهفته در PCM را به دست آورد. استفاده از سامانه جریان بازگشتی تا 50 درصد موجب بهبود راندمان کلی خشک‌کن تا 01/29 درصد نسبت به حالت بدون بازگشت هوا گردید. بااین‌حال، افزایش جریان بازگشتی به 70 درصد به‌دلیل اشباع شدن هوا از رطوبت و افزایش زمان خشک‌سازی، منجر به کاهش کارایی شد.

کلیدواژه‌ها

موضوعات


[1] Jahromi, M. S. B., Iranmanesh, M., Samimi-Akhijahani, H. "Thermo-economic evaluation of a solar dryer with evacuated heat pipe collector and energy storage", Journal of Applied and Computational Sciences in Mechanics, Vol. 32, No. 1, pp. 39-58, 2021, https://doi.org/10.22067/jacsm.2021.56640.0
[2] Iranmanesh, M., Samimi-Akhijahani, H., Jahromi, M. S. B. "CFD modeling and evaluation of the performance of a solar cabinet dryer equipped with evacuated tube solar collector and thermal storage system", Renewable Energy, Vol. 145, pp. 1192-1213, 2020, https://doi.org/10.1016/j.renene.2019.06.038
[3] Salami, P., Safvati, M., Jahromi, M. S. B., Kalantar, V., Samimi-Akhijahani, H. "classification of fruit solar dryers and the role of phase change materials in enhancing performance: a review", Solar Energy, Vol. 297, p. 113570, 2025, https://doi.org/10.1016/j.solener.2025.113570
[4] Jahromi, M. S. B., Sayedolasgari, A., Madhankumar, S., Samimi-Akhijahani, H., Salami, P. "Thermal energy storage-centric solar drying with phase change materials: intelligent optimization via neural and evolutionary regression models", Journal of Energy Storage, Vol. 141, p. 119192, 2026, https://doi.org/10.1016/j.est.2025.119192
[5] Azaizia, Z., Kooli, S., Hamdi, I., Elkhal, W., Guizani, A. A. "Experimental study of a new mixed mode solar greenhouse drying system with and without thermal energy storage for pepper", Renewable Energy, Vol. 145, pp. 1972-1984, 2020, https://doi.org/10.1016/j.renene.2019.07.055
[6] Rabha, D. K., Muthukumar, P. "Performance studies on a forced convection solar dryer integrated with a paraffin wax-based latent heat storage system", Solar Energy, Vol. 149, pp. 214-226, 2017, https://doi.org/10.1016/j.solener.2017.04.012
[7] Murugesan, G. K., Murugesan, C., Sakthivel, M., Tamilkolundu, S. "Experimental investigation on a solar dryer assisted with minimum phase change material (PCM) placed on the inner walls of drying chamber", Journal of Energy Storage, Vol. 98, p. 113069, 2024, https://doi.org/10.1016/j.est.2024.113069
[8] Grecia, K. J., Luce, A. A., Buenaventura, M. A., Ubando, A., Gue, I. H. "Design and evaluation of a mango solar dryer with thermal energy storage and recirculated air", Proc. IEEE 11th Int. Conf. Humanoid, Nanotechnology, Information Technology, Communication and Control, Environment, and Management (HNICEM), pp. 1-5, 2019, https://doi.org/10.1109/HNICEM48295.2019.9072900
[9] Motahayyer, M., Arabhosseini, A., Samimi-Akhijahani, H. "Numerical analysis of thermal performance of a solar dryer and validated with experimental and thermo-graphical data", Solar Energy, Vol. 193, pp. 692-705, 2019, https://doi.org/10.1016/j.solener.2019.10.001
[10] Ajithkumar, A., GaneshKumar, P. "Impact of organic PCM on drying kinetics and nutritional quality of sweet potato in indirect solar dryer", Journal of Energy Storage, Vol. 132, p. 117716, 2025, https://doi.org/10.1016/j.est.2025.117716
[11] Alktranee, M., Al-Yasiri, Q., Mohammed, K. S., Arici, M., Szabo, M., Bencs, P. "Energy, exergy, and economic analysis of indirect solar dryer integrated with phase change material cans", Energy Conversion and Management: X, Vol. 26, p. 100986, 2025, https://doi.org/10.1016/j.ecmx.2025.100986
[12] Aghkhani, M. H., Abasspour-Fard, M. H., Bayati, M. R., Mortezapour, H., Saedi, S. I., Moghimi, A. "Performance analysis of a solar dryer equipped with a recycling air system and desiccant chamber", Journal of Agricultural Machinery, Vol. 3, pp. 92-103, 2014, https://doi.org/10.22067/jam.v3i2.25164
[13] Ahmadi, M., Samimi-Akhijahani, H., Salami, P. "Thermo-economic and drying kinetic analysis of oleaster using a solar dryer integrated with phase change materials and recirculation system", Journal of Energy Storage, Vol. 68, p. 107351, 2023, https://doi.org/10.1016/j.est.2023.107351
[14] Iranmanesh, M., Jahromi, M. S. B. "Effect of forced convection and pcm materials on an indirect solar dryer equipped with evacuated heat pipe collector", Modares Mechanical Engineering, Vol. 19, No. 11, pp. 2607-2614, 2019, https://doi.org/10.1001.1.10275940.1398.19.11.17.1
[15] Jahromi, M. S. B., Kalantar, V., Samimi-Akhijahani, H. "Evaluation of performance, energy, and exergy analysis of a solar parabolic dish collector connected to a dryer with nanofluid and PCM", Journal of Energy Storage, Vol. 98, p. 112969, 2024, https://doi.org/10.1016/j.est.2024.112969
[16] Shalaby, S. M., Bek, M. A., El-Sebaii, A. A. "Solar dryers with PCM as energy storage medium: a review", Renewable and Sustainable Energy Reviews, Vol. 33, pp. 110-116, 2014, https://doi.org/10.1016/j.rser.2014.01.073
[17] Matapour, A., Samimi-Akhijahani, H., Zareei, S. "Experimental and numerical study of thermal performance of a solar rotary dryer with thermal storage mechanism", Journal of Energy Storage, Vol. 82, p. 109843, 2024, https://doi.org/10.1016/j.est.2023.109843
[18] Sabiha, M. A., Saidur, R., Mekhilef, S., Mahian, O. "Progress and latest developments of evacuated tube solar collectors", Renewable and Sustainable Energy Reviews, Vol. 51, pp. 1038-1054, 2015, https://doi.org/10.1016/j.rser.2015.07.016
[19] Jahromi, M. S. B., Kalantar, V., Samimi-Akhijahani, H., Kargarsharifabad, H. "Recent progress on solar cabinet dryers for agricultural products equipped with energy storage using phase change materials", Journal of Energy Storage, Vol. 51, p. 104434, 2022, https://doi.org/10.1016/j.est.2022.104434
[20] Namjoo, M., Golbakhshi, H., Kamandar, M. R., Jahromi, M. S. B. "Performance evaluation using artificial neural network technique and exergetic impact of cold plasma pretreatment on hybrid ultrasound/convective drying of ginger slices", Thermal Science and Engineering Progress, Vol. 73, p. 104679, 2026, https://doi.org/10.1016/j.tsep.2026.104679
[21] Norton, T., Sun, D. W. "Computational fluid dynamics (CFD)- an effective and efficient design and analysis tool for the food industry: a review", Trends in Food Science & Technology, Vol. 17, No. 11, pp. 600-620, 2006, https://doi.org/10.1016/j.tifs.2006.05.004
[22] Yongson, O., Badruddin, I. A., Zainal, Z. A., Narayana, P. A. "Airflow analysis in an air conditioning room", Building and Environment, Vol. 42, No. 3, pp. 1531-1537, 2007, https://doi.org/10.1016/j.buildenv.2006.01.002
[23] Khoshhal, A., Rahimi, M., Alsairafi, A. A. "CFD investigation on the effect of air temperature on air blowing cooling system for preventing tube rupture", International Communications in Heat and Mass Transfer, Vol. 36, No. 7, pp. 750-756, 2009, https://doi.org/10.1016/j.icheatmasstransfer.2009.04.001
[24] Jahromi, M. S. B., Kalantar, V., Samimi-Akhijahani, H. "Design and performance analysis of a new flat solar heating porous collector equipped with vertical copper pipe and porous medium for medicinal plant drying", Energy, Vol. 334, p. 137653, 2025, https://doi.org/10.1016/j.energy.2025.137653
[25] Arabhosseini, A., Samimi-Akhijahani, H., Motahayyer, M. "Increasing the energy and exergy efficiencies of a collector using porous and recycling system", Renewable Energy, Vol. 132, pp. 308-325, 2019, https://doi.org/10.1016/j.renene.2018.07.132
[26] Gunjo, D. G., Mahanta, P., Robi, P. S. "Exergy and energy analysis of a novel type solar collector under steady state condition: experimental and CFD analysis", Renewable Energy, Vol. 114, pp. 655-669, 2017, https://doi.org/10.1016/j.renene.2017.07.072
[27] Hung, T. C., Huang, T. J., Lee, D. S., Lin, C. H., Pei, B. S., Li, Z. Y. "Numerical analysis and experimental validation of heat transfer characteristic for flat-plate solar air collector", Applied Thermal Engineering, Vol. 111, pp. 1025-1038, 2017, https://doi.org/10.1016/j.applthermaleng.2016.09.126
[28] Rehman, S., Mohandes, M. "Artificial neural network estimation of global solar radiation using air temperature and relative humidity", Energy Policy, Vol. 36, No. 2, pp. 571-576, 2007, https://doi.org/10.1016/j.enpol.2007.09.033
[29] Aboghrara, A. M., Baharudin, B. T., Alghoul, M. A., Adam, N. M., Hairuddin, A. A., Hasan, H. A. "Performance analysis of solar air heater with jet impingement on corrugated absorber plate", Case Studies in Thermal Engineering, Vol. 10, pp. 111-120, 2017, https://doi.org/10.1016/j.csite.2017.04.002
[30] Khazaei, J., Chegini, G. R., Bakhshiani, M. "A novel alternative method for modeling the effects of air temperature and slice thickness on quality and drying kinetics of tomato slices: superposition technique", Drying Technology, Vol. 26, No. 6, pp. 759-775, 2008, https://doi.org/10.1080/07373930802046427
[31] Rashidi, M., Arabhosseini, A., Samimi-Akhijahani, H. "Evaluation of energetic and exergetic efficiency of a solar collector equipped with porous plate, recycling system and reflectors", Iranian Journal of Biosystems Engineering, Vol. 51, No. 2, pp. 371-384, 2020, https://doi.org/10.22059/ijbse.2020.279686.665183
[32] Mokhtarian, M., Tavakolipour, H., Ashtari, A. K. "Effects of solar drying along with air recycling system on physicochemical and sensory properties of dehydrated pistachio nuts", LWT, Vol. 75, pp. 202-209, 2017, https://doi.org/10.1016/j.lwt.2016.08.056
[33] Madhankumar, S., Kumar, M. L., Jahromi, M. S. B., Kumar, K. D. H., Singh, A. K., Kumar, V. "Thermal and environmental assessment of a solar dryer with phase change material and enhanced absorber plates", Journal of Energy Storage, Vol. 153, p. 121045, 2026, https://doi.org/10.1016/j.est.2026.121045
[34] Pawar, V. R., and Sobhansarbandi, S., "CFD modeling of a thermal energy storage based heat pipe evacuated tube solar collector", Journal of Energy Storage, Vol. 30, p. 101528, 2020, https://doi.org/10.1016/j.est.2020.101528