Influence of functionalized carbon flake on phase change characteristics of deionized (DI) water for cool thermal storage system

Abstract

The current work aims to study the influence of thermal-resistance (R) and the time constant (τ) in phase change properties of carbon flake-based phase change materials (CPCM) experimentally. The CPCMs were prepared using chemically functionalized graphene flake (f-GP) in three various mass fractions (0.25%, 0.50%, and 0.75%) suspended in deionized (DI) water. The phase transition characteristics were recorded using DSC214-polyma with a heat-flow rate of 1 K/min. The remarkable variation in the peak crystallization and melting during charging and discharging processes were recorded with the combined τ -R correction method. The true peak during charging (−12.21 °C) and discharging (3.91 °C) processes is recorded through the correction of time constant for CPCM with 0.75% of f-GP. In addition, the CPCM with 0.75% f-GP has a maximum reduction in melting and freezing time of 36.01% and 27.75%, respectively. The prediction of phase change properties (peak crystallization and melting temperatures) is very important to design a cool thermal energy storage (CTES) system with maximum storage density. The selection of correct operating temperature of the CTES system reduces the energy input to the chiller plant.

Keywords:

• Thermal resistance
• time constant
• peak crystallization
• nucleation rate
• freezing time

Acknowledgments

The authors wish to thank the DSC Laboratory, Department of Mechanical Engineering, SRM Institute of Science and Technology, Kattankulathur for providing the facility for carrying out this research.

Disclosure statement

The authors declare that they have no conflict of interest.

Authors' contributions

A Sathishkumar performed the experimentation in various heat flow conditions and consolidate the results. M Cheralathan and A Sathishkumar interrupt the physical-scenario behind the variation of peak crystallization and melting properties.

Ethical approval

Authors are attested that this paper has not been published elsewhere, the work has not been submitted simultaneously for publication elsewhere and the results presented in this work are true and not manipulated.