Thermal Performance Enhancement of Triplex Tube Latent Thermal Storage Using Fins-Nano-Phase Change Material Technique

ABSTRACT

Latent heat thermal energy storage (LHTES) systems using a phase change material (PCM) can reduce the heat-transfer rates during charging/discharging processes because of their inherently low thermal conductivity. In this study, heat-transfer enhancement using various configurations of longitudinal fins employing both a PCM and a nano-PCM in a large triplex-tube heat exchanger (TTHX) was numerically investigated via the Fluent 15 software. The results showed that the thermal conductivity of the pure PCM (0.2 W/m K) can be observably enhanced by dispersing 10% alumina (Al₂O₃) to 25%. Therefore, the melting time is reduced to 12%, 11%, and 17% for the internal, internal-external, and external fins, respectively, compared with the case of the PCM without nanoparticle. It is concluded that the model of external fins-nano-PCM embedded in a large TTHX is the most efficient model for achieving complete PCM melting in a short time (188 min), where improving the thermal performance to 14% and 11% compared with the TTHX with internal and internal-external fins-nano-PCM, respectively. The simulation results are validated and agree well with experimental results for the PCM and nano-PCM.

Acknowledgments

The authors gratefully appreciate the financial support provided by the Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia (UKM), Malaysia.

Additional information

Notes on contributors

Ammar M. Abdulateef

Ammar M. Abdulateef is a Ph.D. candidate at the Solar Energy Research Institute, Universiti Kebangsaan Malaysia, Malaysia. He received the B.Sc. degree in Mechanical Engineering from University of Baghdad, College of Engineering, Iraq in 1998. He received his Master's degree in Mechanical Engineering from the Universiti Kebangsaan Malaysia, Malaysia in 2010. He worked as a Mechanical Engineering lecturer at the University of Diyala, Iraq. His research involves solar energy, phase-change material, heat exchangers, and nano-particles.

Sohif Mat

Sohif Mat is a professor Dr. and a principal research fellow and head of industry and community partnership at Solar Energy Research Institute at the Universiti Kebangsaan Malaysia. His specialization is in solar thermal, liquid and solid desiccant for drying and cooling, latent heat storage system, energy management and green buildings. Past and current PhD projects supervised by him includes Latent Heat Storage (LHS) with Fins using PCM, nanomaterial to enhance the heat transfer in LHS and Liquid Desiccant Evaporative Cooling. Currently, he is the chairman of the task force under the National Steering Committee under the government agency, Ministry of Energy, Green Technology and Water (KeTTha) for the development of the Solar Thermal Road map in Malaysia.

Jasim Abdulateef

Jasim Abdulateef is an assistant professor of mechanical engineering at the University of Diyala, Iraq. He received his B.Sc. degree in Mechanical Engineering from the University of Baghdad, College of Engineering, Iraq in 1999. In 2001, he received his Master's degree in Mechanical Engineering from the University of Baghdad, College of Engineering, Iraq. He received his Ph.D. in Mechanical Engineering from Universiti Kebangsaan Malaysia in 2011. His research involves solar thermal cooling systems, solar cells, and renewable energy.

Kamaruzzaman Sopian

Kamaruzzaman Sopian received his B.Sc. degree in Mechanical Engineering from the University of Wisconsin-Madison in 1985, his Master's degree in Energy Resources (Solar Energy) from the University of Pittsburgh in 1989, and his Ph.D. in Mechanical Engineering from the University of Miami-Coral Gables in 1997. He is a professor in the department of Mechanical Engineering, Universiti Kebangsaan Malaysia. He is a director of the Solar Energy Research Institute, at the same university. His research involves solar energy, photovoltaic power systems, solar thermal systems, and renewable energy.

Abduljalil A. Al-Abidi

Abduljalil Al-Abidi is an assistant professor at the department of HVAC Engineering, Sana'a Community College, Yemen. He received his B.Sc. degree in Mechanical Engineering from Sana'a University, Sana'a, Yemen in 1999. In 2003, he received his Master's degree in air-conditioning engineering from Al-Balqa` Applied University, Salt, Jordan. He received his Ph.D. from Universiti Kebangsaan Malaysia in 2014 in renewable energy. He is a member of the World Society of Sustainable Energy Technologies. His research involves thermal energy storage, phase-change materials, solar energy, and solar thermal cooling systems.