Abstract
The melting and freezing of Phase Change Materials (PCMs) is categorized as a moving boundary problem. For this reason the mathematical solution to study the behaviour of practical applications is only possible via complex numerical approximations. However for a preliminary design the main concern is to select the optimum thermal characteristics of the PCM storage unit, for both melting and freezing. This is to be done before the detailed design by integrating an optimization algorithm with a numerical simulation. The application of using PCMs to harness the waste heat from non-industrial grey water is investigated as a case of study. For this purpose, the 2-phase analytical solution to the Stefan problem is coupled with the particle swarm optimizer (PSO) to find the best combination of thermal characteristics within the prescribed boundary conditions of this case study. Results show that the optimum phase change temperature lies between 20 and 22 °C, depending on various sets of input parameters. At the same time the ratio of latent to sensible heat transferred by the PCM highly influences this optimum temperature for the combination of both melting and freezing. Similarly results show melting being faster and more intensive in term of latent heat charging compared to a higher sensible heat discharging while freezing.
Original language | English |
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Article number | 118574 |
Journal | International Journal of Heat and Mass Transfer |
Volume | 144 |
Early online date | 3 Sept 2019 |
DOIs | |
Publication status | Published - Dec 2019 |
Bibliographical note
NOTICE: this is the author’s version of a work that was accepted for publication in International Journal of Heat and Mass Transfer. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Heat and Mass Transfer [144, (2019)] DOI: 10.1016/j.ijheatmasstransfer.2019.118574© 2019, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/10.1016/j.ijheatmasstransfer.2019.118574
Keywords
- Neumann solution
- Particle swarm optimization
- Phase change materials
- Stefan problem
- Thermal characteristics
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanical Engineering
- Fluid Flow and Transfer Processes