Optimization of the PCM-integrated solar domestic hot water system under different thermal stratification conditions

Document Type : Research Paper

Authors

1 Mechanical Engineering Department, K.N. Toosi University of Technology Tehran, Tehran, Iran

2 School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran

Abstract

Many researchers have investigated how to increase the overall efficiency of solar-driven thermal systems. Several key parameters, such as collector efficiency and storage tank characteristics, may impose some constraints on the annual solar fraction (ASF) of such systems. In this paper, the behaviour of integrating the phase change material (PCM) in SDHW systems is modelled and optimized numerically. Coupled collector and partly stratified PCM-embedded storage tank governing equations are utilized to simulate the overall performance of the system. The developed code presents the monthly behaviour of the system including the solar fraction and the storage tank temperature profile. The results indicate that the stratification of the storage tank will increase the ASF up to about 4.6%. Additionally, it is found that the optimum amount for the PCM and its melting temperature is changed as the tank stratification goes from the fully mixed to the fully stratified state. Integrating the PCM in the storage tank leads to increases of 5.3% in the ASF for a single-node tank, while a rise of only 0.7% is seen for the stratified storage tank.

Keywords

References

[1]  Thirugnanasambandam M., Iniyan S., Goic R., A Review of Solar Thermal Technologies, Renewable and Sustainable Energy Reviews (2010) 14: 312–322.
[2]  Shukla A., Buddhi D., Sawhney R.L., Solar Water Heaters with Phase Change Material Thermal Energy Storage Medium, A Review, Renewable and Sustainable Energy Reviews (2009) 13: 2119–2125.
[3] Sharma A., Chen C.R., Solar Water Heating System with Phase Change Materials, International Review of Chemical Engineering (I. RE. CH. E.) (2009) 1: 297–307.
[4]  Shukla R., Sumathy K., Erickson P., Gong J., Recent Advances in the Solar Water Heating Systems, A Review, Renewable and Sustainable Energy Reviews (2013) 19:173–190.
[5]  Sharma S.D., Sagara K., Latent Heat Storage Materials and Systems, A Review, International Journal of Green Energy (2005) 2: 1–56.
[6]  Haillot D., Nepveu F., Goetz V., Py X., Benabdelkarim M., High Performance Storage Composite for the Enhancement of Solar Domestic Hot Water Systems, Part 2, Numerical System Analysis, Solar Energy  (2012) 86: 64–77.
[7]  Padovan R., Manzan M., Genetic Optimization of a PCM Enhanced Storage Tank for Solar Domestic Hot Water Systems, Solar Energy (2014) 103: 563–573.
[8]  Mather D.W., Hollands K.G.T., Wright J.L., Single-and Multi-Tank Energy Storage for Solar Heating Systems, Fundamentals, Solar Energy (2002) 73: 3–13.
[9]  Rhee J., Campbell A., Mariadass A., Morhous B., Temperature Stratification from Thermal Diodes in Solar Hot Water Storage Tank, Solar Energy (2010) 84: 507–511.
[10]  Andersen E., Furbo S., Fan J., Multilayer Fabric Stratification Pipes for Solar Tanks, Solar Energy (2007) 81: 1219–1226.
[11] Haillot D., Franquet E., Gibout S., Bédécarrats J.P., Optimization of Solar DHW System Including PCM Media, Applied Energy (2013) 109: 470–475.
[12]  Duffie J., Beckman W., Worek W.M., Solar Engineering of Thermal Processes, 2nd Edition, 1994. DOI:10.1115/1.2930068.
[13] Sharma A., Tyagi V. V, Chen C.R., Buddhi D., Review on Thermal Energy Storage with Phase Change Materials and Applications, Renewable and Sustainable Energy Reviews (2009) 13: 318–345.
[14] Khalifa A. J. N., Jabbar  R. A. A.,Conventional Versus Storage Domestic Solar Hot Water Systems, A Comparative Performance Study, Energy Conversion and Management (2010) 51: 265–270.
[15] Nkwetta D.N., Vouillamoz P.E., Haghighat F., El-Mankibi M., Moreau A., Daoud A., Impact of Phase Change Materials Types and Positioning on Hot Water Tank Thermal Performance, Using Measured Water Demand Profile, Applied Thermal Engineering (2014) 67:460–468.
Energy Equipment and Systems
Volume 4, Issue 2
Autumn 2016
Pages 271-279

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