Experimental Study On Heat Transfer Performance Of Solar Thermoelectric Generators Using MWCNT-Distilled Water And GNP-Distilled Water Nanofluids As Coolants

Öz

The solar thermoelectric generators (STEGs) have emerged during the past decade as a promising substitutional among other green power production systems. A solar thermoelectric generator (STEG) is a system that can generate electrical energy directly from solar energy without any intermediate energy forms such as work in the traditional power generation systems. Recent developments in solar thermoelectric generator have achieved several improvements as a result of its optimized systems such as concentrated systems and also the boosts from nanotechnology. In this study, a concentrator thermoelectric generator (CTEG) using Graphene Nanoplatelets (GNPs), and Multiwall Carbon Nanotubes (MWCNTs) dispersed in distilled water as base fluid was investigated experimentally. The CTEG system was designed, constructed in Karabük University Energy Systems labs, Turkey and have been commissioned outdoor by testing, balancing and adjusting. Experiments were performed for 0.25 wt.% nanoparticle mass concentration of MWCNTs-distilled water and GNPs-distilled water nanofluids with a constant volume rate of flow (ν ̇=0.5 L/min). Experiments study aimed to study effect of nanoparticle types on thermal and electrical energetic efficiency. The obtained results showed that the CTEG is enable to generate (Emax=3.7 W) of electrical power output for an average temperature difference of 38°C. MWCNTs-distilled water nanofluid presented an enhancement in electrical performance more than GNPs-distilled water nanofluid and distilled water, while GNPs-distilled water nanofluid presented maximum thermal increment. The total efficiency for the day-long periods were 16.34%, 24.03% and 20.21% for distilled water, GNPs-distilled water, MWCNTs-distilled water respectively. The results of the study made a solid basics about the prospects of CTEG applications related with nanotechnology to be one of the potential choices for cooling technique by using different types of nanofluids as coolants.

Anahtar Kelimeler

• Solar Energy
• Concentrator Thermoelectric Generator (CTEG)
• Thermoelectric modules
• Nanofluids
• Cooling technique

Soğutucu Olarak MWCNT-Su ve GNP-Su Nanoakışkanları Kullanan Güneş Enerjili Termoelektrik Jeneratörlerin Isı Transfer Performansının Deneysel Olarak İncelenmesi

Öz

Son yıllarda, güneş enerjili termoelektrik jeneratörler diğer yeşil güç üretim sistemleri arasında umut verici bir konu olarak ortaya çıkmıştır. Geleneksel enerji üretim sistemlerindeki gibi bir ara enerji formu olmaksızın güneş enerjili termoelektrik jeneratör doğrudan güneş enerjisinden elektrik enerjisi üretebilen bir sistemdir. Güneş enerjili termoelektrik jeneratördeki son gelişmelerle, konsantre sistemler gibi optimize edilmiş sistemlerin ve ayrıca nanoteknolojinin sağladığı desteklerin bir sonucu olarak çeşitli iyileştirmeler sağlanmıştır. Bu çalışmada, baz akışkan olarak su içinde dağıtılan Grafen Nanoplateletler (GNP’ler) ve Çok Duvarlı Karbon Nanotüpler (MWCNT’ler) kullanan bir yoğunlaştırıcı termoelektrik jeneratör (CTEG) deneysel olarak incelenmiştir. Karabük Üniversitesi laboratuvarlarında yoğunlaştırıcı termoelektrik jeneratör sistemi (CTEG) tasarlanıp, imalatı gerçekleştirilmiş ve dış şartlarda deneyler yapılmıştır. Deneyler, MWCNTs-Su ve GNPs-Su nanoakışkanlarının ağırlıkça %0.25 nanoparçacık kütle konsantrasyonu için sabit debide (ν ̇=0.5 L/dk) gerçekleştirilmiştir. Deneylerde termal ve elektriksel enerji verimliliği üzerindeki nanoparçacık tipinin etkisi amaçlanmıştır. Elde edilen sonuçlar, CTEG sisteminin 38°C’lik bir ortalama sıcaklık farkı için maksimum 3.7 W elektrik gücü çıkışı üretmeye olanak sağladığını göstermiştir. Elektrik performansı için MWCNTs-su nanoakışkanın artış oranı diğer akışkanlara göre daha büyükken GNP’ler-su nanoakışkanın termal performansı maksimum artışı göstermiştir. Günlük toplam verim değerleri saf su, GNPs-su, MWCNTs-su için sırasıyla %16.34, %24.03 ve %20.21 olarak hesaplanmıştır. Çalışmanın sonuçları, CTEG uygulamalarındaki soğutma tekniği için farklı türlerde nanoakışkanların kullanımının potansiyel seçeneklerden biri olma beklentileri hakkında sağlam bir temel oluşturmuştur.

Anahtar Kelimeler

• Güneş enerjisi
• Yoğunlaştırıcı Termoelektrik jeneratör
• nanoakışkanlar
• soğutma tekniği

Kaynakça

1. [1] AFSHARİ, F., “Experimental study for comparing heating and cooling performance of thermoelectric Peltier.” Politeknik Dergisi, 23(3), pp.889-894 (2020).
2. [2] Ahiska, R., Savaş, Y. And Hakan, I.Ş.I.K., “Mikro denetleyicili smps ve kontrol sisteminin termoelektrik uygulamalari. ” Politeknik dergisi, 5(1):59-68 (2002).
3. [3] Fakoor, R., Ladhak, F., Nazi, A., Huber, M.,“Using deep learning to enhance cancer diagnosis and classification”, Proceedings of the 30th International Conference on Machine Learning, Atlanta, Georgia, (2013).
4. [4] Abdelkareem, Mohammad Ali, et al. “Prospects of Thermoelectric generators with nanofluid.” Thermal Science and Engineering Progress (2022).
5. [5] ÖZBAŞ, E., “Experimental investigation of passive water cooling in solar heating thermoelectric generator.” Politeknik Dergisi, 23(4), pp.1231-1236 (2019).
6. [6] ŞENER, M., mertkan ARSLAN, F., GÜRSES, O. and GÜRLEK, G., “Experimental investigation of thermoelectric self-cooling system for the cooling of ultrasonic transducer drivers. ” Politeknik Dergisi, pp.1-1 (2021).
7. [7] Shanmugam, S., Eswaramoorthy, M., and Veerappan, A. R., "Modeling and analysis of a solar parabolic dish thermoelectric generator", Energy Sources, Part A: Recovery, Utilization, And Environmental Effects, 36 (14): 1531–1539 (2014).
8. [8] Fan, H., Singh, R., and Akbarzadeh, A., "Electric power generation from thermoelectric cells using a solar dish concentrator", Journal Of Electronic Materials, 40 (5): 1311–1320 (2011).

9. [9] Sundarraj, P., Taylor, R. A., Banerjee, D., Maity, D., and Roy, S. S., "Experimental and theoretical analysis of a hybrid solar thermoelectric generator with forced convection cooling", Journal Of Physics D: Applied Physics, 50 (1): 15501 (2016).
10. [10] Muthu, G., Shanmugam, S., and Veerappan, A. R., "Theoretical and experimental study on a thermoelectric generator using concentrated solar thermal energy", Journal Of Electronic Materials, 48 (5): 2876–2885 (2019).
11. [11] Ahammed, N., Asirvatham, L. G., and Wongwises, S., "Entropy generation analysis of graphene–alumina hybrid nanofluid in multiport minichannel heat exchanger coupled with thermoelectric cooler", International Journal Of Heat And Mass Transfer, 103: 1084–1097 (2016).
12. [12] Nnanna, A. G. A., Rutherford, W., Elomar, W., and Sankowski, B., "Assessment of thermoelectric module with nanofluid heat exchanger", Applied Thermal Engineering, 29 (2–3): 491–500 (2009).
13. [13] Chang, H., Kao, M.-J., Cho, K.-C., Chen, S.-L., Chu, K.-H., and Chen, C.-C., "Integration of CuO thin films and dye-sensitized solar cells for thermoelectric generators", Current Applied Physics, 11 (4): S19–S22 (2011).
14. [14] Nasrin, R., Rahim, N. A., Fayaz, H., and Hasanuzzaman, M., "Water/MWCNT nanofluid based cooling system of PVT: Experimental and numerical research", Renewable Energy, 121: 286–300 (2018).
15. [15] Contreras, E. M. C., Oliveira, G. A., and Bandarra Filho, E. P., "Experimental analysis of the thermohydraulic performance of graphene and silver nanofluids in automotive cooling systems", International Journal Of Heat And Mass Transfer, 132: 375–387 (2019).
16. [16] Sengers, J. V and Watson, J. T. R., "Improved international formulations for the viscosity and thermal conductivity of water substance", Journal Of Physical And Chemical Reference Data, 15 (4): 1291–1314 (1986).
17. [17] Pak, B. C. and Cho, Y. I., "Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles", Experimental Heat Transfer An International Journal, 11 (2): 151–170 (1998).
18. [18] Xuan, Y. and Roetzel, W., "Conceptions for heat transfer correlation of nanofluids", International Journal Of Heat And Mass Transfer, 43 (19): 3701–3707 (2000).
19. [19] MAXWELL-GARNETT, J. C., "Colours in metal glasses and in metallic films", Phil. Trans. R. Soc. Lond, A, 203: 385–420 (1904).
20. [20] Rejeb, O., Shittu, S., Li, G., Ghenai, C., Zhao, X., Ménézo, C., Jemni, A., hedi Jomaa, M. and Bettayeb, M., “Comparative investigation of concentrated photovoltaic thermal-thermoelectric with nanofluid cooling.” Energy Conversion and Management, 235, p.113968,(2021).