Enhancement of the Thermal Efficiency of the Evacuated Tubes Solar Water Heater by Adding a Reflector

Baqer A. Alhabeeb, Thualfaqir J. Kadhim, Hasan T. Hashim, Hayder N. Mohammed

Abstract


Evacuated tube solar collector (ETSC) is an efficient means used to harvest direct incident solar energy and convert it into thermal energy. Still always there is a rare area of the tube itself which is not facing the sunshine. Thus, reflectors are used to maximize the collecting area. This study investigated the performance of 21 different configurations of the  ETSC system. In this research, three different types of reflective materials were used such as aluminum foil, mirror, and white painting. The aluminum foil was used in five different shapes such as a flat surface, parabolic, V-shape, vertical-zigzag and horizontal-zigzag. While the mirror and white painting were used in a flat shape only. All those types of reflectors were installed at a distance of (0.22, 0.17 or 0.12) m behind ETSC’s center. The experiments were conducted during 11th-13th December 2018 under Kerbala, Iraq climate. Each system was compared with a reference one which was set without a reflector. Based on thermal efficiency calculations, the results showed that the flat mirror at a distance of 0.17 m was the best. Also, the orientation of the zigzag surface has a significant effect onefficiency.


Keywords


: evacuated tube , reflector , solar thermal , solar water heater

Full Text:

PDF

References


REFERENCES

United States Environmental Protection Agency, State Renewable Energy Resources. https:// www.epa.gov/statelocalenergy/state-renewable-energy-resources (accessed 1 March 2019).

Y. Goswami, F. Kreith and J. F. Kreider, Principles of Solar Engineering, Taylor & Francis , Philadelphia, (2000) PA, USA.

W.L.R Emmett, Apparatus for Utilizing Solar Heat, 980,505 (1911) U.S. Patent.

Silicon Solar Inc. , SunMaxx, Information Guide: Evacuated Tube Solar Collector. (2008). http://www .gte-systems.com/PDF/SHW-GIB-001-evacuated-tube-solar-collectors.pdf.

M. A. Sabiha , R. Saidur , S. Mekhilef and O. Mahian, Progress and Latest Developments of Evacuated Tube Solar Collectors, Renew. Sustain. Energy Rev. 51 (2015) 1038–1054.https://doi.org /10.1016/j.rser. 2015.07.016 .

Alternative Energy Tutorial: Solar Evacuated Tube Collectors for Solar Hot Water.http://www.alternativ e-energy-tutorials.com/solar-hot-water/evacuated-tube-collector.html (accessed 25 February 2019).

J. Ferdous, M.R.I. Sarker and R. A. Beg, , Experimental Study of a Hybrid Evacuated Tube Solar Collector Using Methanol as Working Fluid , IJERM 5 (2018) 69-74.

M.A. Sabiha , R. Saidur, S. Hassani , Z. Said and S. Mekhilef, , Energy Performance of an Evacuated Tube Solar Collector Using Single Walled Carbon Nanotubes Nanofluids, Energy Convers. Manag. 105 (2015) 1377–1388. https://doi.org/10.1016/j.enco nman. 201 5.09.009.

S. Iranmanesh , H. C. Ong , B. C. Ang , E. Sadeghinezhad , A. Esmaeilzadeh and M. Mehrali, Thermal Performance Enhancement of an Evacuated Tube Solar Collector Using Graphene Nanoplatelets Nanofluid, J. Clean. Prod., 162 (2017) 121-129. https://doi.org/10.1016/j.jclepro.2017.05.175.

H. A. Hussain, Q. Jawad and K. F. Sultan, Experimental Analysis on Thermal Efficiency of Evacuated Tube Solar Collector by Using Nanoflids, Int. J. Sustain. Green Energy 4 (2015) 19-28. doi:10.11648/j.ijrse.s.2015040301.14.

M.S. Abd-Elhady , M. Nasreldin and M.N. Elsheikh, Improving the Performance of Evacuated Tube Heat Pipe Collectors Using Oil and Foamed Metals, Ain Shams Eng. J. 9 (2018) 2683–2689. https://doi.org/ 10.1016/j.asej.2017.10.001.

N. H. Mujawar and S. M. Shaikh, Thermal Performance Investigation of Evacuated Tube Heat Pipe Solar Collector with Nanofluids, Int. J. Eng. Sci. Res. Tech. 5 (2016) 824-837. doi: 10.5281 /zenodo.221114.

P. Thomas, P. Ajith, A. Palayakkodan and M. Natarajan, Experimental Analysis of Evacuated Tubular Collectors with Plain & Concave Reflectors, Int. J. Eng. Sci. Res. Tech , 3 (2014) 852-855.

D. N. Nkwetta, M. Smyth, A. Zacharopoulos and T. Hyde, In-door Experimental Analysis of Concentrated and Non-Concentrated Evacuated Tube Heat Pipe Collectors for Medium Temperature Applications, Energy and Build. 47 (2012) 674–681. https://doi.org/10.1016/j.enbuild.2012.01.010.

Kumar, S. Kumar, U. Nagar, and A. Yadav, Experimental Study of Thermal Performance of One-Ended Evacuated Tubes for Producing Hot Air, J. Sol. Energy. 2013 (2013) 1-6. http://dx.doi.org /10.1155/2013/524715.

K. Alkhaledi, K. H. Means, S. Bendak , A. M. Arnold and J. Jones, Evacuated Solar Tube Performance Enhancement Evaluation, J. Eng. Res. 5 (2017) 207-222. http://kuwaitjournals.org/jer/ index.php/JER/article/view/2482.

M. Bisla and P. Mor, Experimental Analysis of Evacuated Tube Collector with Parabolic and Flat Reflector, Int. J. Res. Manag. Sci. Technol. 5 (2017) 109-114. http://www.ijrmst.org/download/vol5no1/ paper15.pdf.

S. M. S. Al-Mashat and A. A. Hasan, Evaluation of Convective Heat Transfer and Natural Circulation in an Evacuated Tube Solar Collector, J. Eng. 19 (2013) 613-628. https://www.iasj.net/iasj?func= fulltext& aId=72185.

SD Card Real Time Data Recorder 12-channels Temperature Recorder Model BTM-4208SD: Operation Manual.

Data Logging Solar Power Meter Model TES-132: Instruction Manual.

Kline, S. J., and McClintock, F. A., 1953, “Describing Uncertainties in Single-Sample Experiments,” Mech. Eng., 75, pp. 3–8.

M. I. Alhamid, Nasruddin, N. Aisyah, and Sholahudin, Characteristics of Evacuated Tubular Solar Thermal Collector as Input Energy for Cooling System at Universitas Indonesia , AIP Conf. Proc. 1826, 020016 (2017). https://doi.org/10.1063/1.497 9232.

Engineering ToolBox, (2012). Materials - Light Reflecting Factors. https://www.engineeringtoolbox .com/light-material-reflecting-factor-d_1842.html (2012) (accessed 8 March 2019).