Computational Simulation of Natural Convection in a Porous Cavity Packed With a Nano‐Encapsulated Phase Change Material‐Water Mixture and Fitted With an Exothermic Circular Battery Cell

Molecular dynamics simulations of nano-encapsulated and nanoparticle-enhanced thermal energy storage phase change materials

Purpose This paper aims to study the natural convection from a heated T-open pipe of nanoencapsulated phase change material in a cavity. The impact of the presence of nanoencapsulated phase change materials (NEPCM) in water was studied on the thermal behavior of these novel nanoliquids in the presence of natural convection flows. The entropy generation for these nanoliquids was also investigated. Design/methodology/approach The NEPCM is modeled as a lumped phase change nanoparticle with a phase change material core and a polymer shell. The governing equations for a uniform mixture of NEPCM-water are written based on the conservation of mass, energy and also fluid motion. The natural convection effects were also taken into account. The finite element method was used to solve the governing equations. The entropy generation was also computed and studied. Findings Increasing the aspect ratio (AR) from 0.05 to 0.2 enhanced the average Nusselt number by 9%, while total entropy generation rose by 13%, indicating improved convective heat transfer near the bottom wall due to increased surface area. Enhancing the NEPCM nano particles volume fraction from 0 to 0.05 led to a 15% increase in heat transfer efficiency and a 9% rise in entropy, with negligible change in flow patterns. Growing the NEPCM fusion temperature from 0.1 to 0.5 slightly improved the Nusselt number by 5% and increased entropy by 3%, showing minor thermal gains with limited hydrodynamic impact. Practical implications NEPCMs have demonstrated significant potential in heat and mass transfer for cooling systems and thermal energy storage. Encapsulation technology has been widely used to improve the stability, specificity and bioavailability of essential food ingredients, as well as the performance of NEPCM suspensions in cooling applications. Additionally, the NEPCM suspensions use the latent heat of nanoparticles and can effectively control surface temperatures. Originality/value The natural convection heat transfer and the entropy generation of NEPCM suspension are addressed in an enclosure with T-open heated walls for the first time.

Purpose This paper aims to focuses on by investigate the heat transmission and free convective flow of a suspension of nano encapsulated phase change materials (NEPCMs) within an enclosure. Particles of NEPCM have a core-shell structure, with phase change material (PCM) serving as the core. Design/methodology/approach The enclosure consists of a square chamber with an insulated wall on top and bottom and vertical walls that are differently heated. The governing equations are investigated using the finite element technique. A grid inspection and validation test are done to confirm the precision of the results. Findings The effects of fusion temperature (varying from 0.1 to 0.9), Stefan number (changing from 0.2 to 0.7), Rayleigh number (varying from 103 to 106) and volume fraction of NEPCM nanoparticles (changing from 0 to 0.05) on the streamlines, isotherms, heat capacity ratio and average Nusselt number are investigated using graphs and tables. From this investigation, it is found that using a NEPCM nano suspension results in a significant enhancement in heat transfer compared to pure fluid. This augmentation becomes more important for the low Stefan number, which is around 16.57% approximately at 0.2. Secondary recirculation is formed near the upper left corner as a result of non-uniform heating of the left vertical border. This eddy expands notably as the Rayleigh number rises. The study findings indicate that the NEPCM nanosuspension has the potential to act as a smart working fluid, significantly enhancing average Nusselt numbers in enclosed chambers. Research limitations/implications The NEPCM particle consists of a core (n-octadecane, a phase-change material) and a shell (PMMA, an encapsulation material). The host fluid water and the NEPCM particles are considered to form a dilute suspension. Practical implications Using NEPCMs in energy storage thermal systems show potential for improving heat transfer efficiency in several engineering applications. NEPCMs merge the beneficial characteristics of PCMs with the enhanced thermal conductivity of nanoparticles, providing a flexible alternative for effective thermal energy storage and control. Originality/value This paper aims to explore the free convective flow and heat transmission of NEPCM water-type nanofluid in a square chamber with an insulated top boundary, a uniformly heated bottom boundary, a cooled right boundary and a non-uniformly heated left boundary.

Thermal management and natural convection flow of nano encapsulated phase change material (NEPCM)-water suspension in a reverse T-shaped porous cavity enshrining two hot corrugated baffles: A boost to renewable energy storage

Natural convective flow and heat transfer of Nano-Encapsulated Phase Change Materials (NEPCMs) in a cavity

Nanoencapsulation of phase change material with CuO nanoparticles: Development of thermal properties for energy storage

Irreversibility analysis of thermally driven flow of a water-based suspension with dispersed nano-sized capsules of phase change material

Exploring sustainable energy solutions, Nano Encapsulated Phase Change Materials (NEPCM) have demonstrated significant potential in heat and mass transfer and thermal energy storage. A scientometric study investigated trends and categories in NEPCM research from 2002 to 2023, revealing an exponential growth since 2005, peaking in 2021 with 66 publications. The study encompassed 397 records, refined to 343, with 94.5% being original research articles. China is leading in contributions with 123 publications (35.9%), followed by Saudi Arabia, with King Khalid University producing 31 publications. “Journal of Energy Storage” is the primary source with 40 publications (11.7%). Keyword analysis focused on phase change materials, nanoencapsulation, and thermal energy storage. The research was categorized into six segments, with Synthesis of Nanoparticles being paramount (56%), and diverse computational techniques and Radiation’s impact on NEPCM performance also emphasized. 82% of studies in the “Enhancement” category showed increased heat transfer through techniques like Nanoencapsulation. Natural/Free Convection dominated “Convection Type” research (46%), and Porous Media and Clear Flow were significant in “Medium Type,” contributing to 78%. This study unveils the growth, diverse methodologies, and applications in NEPCM, laying a foundation for future advancements in sustainable energy solutions.

Natural convection heat transfer analysis of a nano-encapsulated phase change material (NEPCM) confined in a porous square chamber with two heat sources

Engineered leathers for extreme cold weather application

• Encapsulated phase change fluids significantly enhance solar heat transfer. • Composite materials improve thermal storage efficiency in solar systems. • Stable, high-performance composite materials support long-term solar energy use. • Eco-friendly phase change materials foster sustainability in thermal applications. • Scalable methods support low-cost production of solar thermal materials. Micro- and nano-encapsulated composite phase change material-based heat transfer fluids represent a promising advancement for solar energy systems by significantly enhancing heat transfer and thermal energy storage capabilities. This review addresses the critical limitations of conventional heat transfer fluids, such as low thermal conductivity and limited energy storage capacity, which hinder solar thermal system performance and efficiency. The integration of advanced encapsulated phase change materials is hypothesized to overcome these challenges by simultaneously augmenting thermal storage capacity and heat conduction, thus optimizing the overall solar system performance. This paper systematically reviews recent progress in the selection of phase change materials tailored for solar applications, innovative encapsulation techniques, and the development of micro- and nano-encapsulated composite fluids with improved thermophysical properties. Applications in various solar thermal systems are examined to highlight their practical potential. Key findings from experimental and theoretical studies demonstrate that these advanced composite materials and fluids can improve thermal conductivity by up to 471 % and enhance energy storage efficiency by 92 % compared to traditional materials and heat transfer fluids. Despite these promising results, challenges remain, including scalability of manufacturing processes, long-term thermal and chemical stability, and environmental sustainability of materials. The review emphasizes the need for further research focused on scalable production methods, durability testing, and eco-friendly material development. Overcoming these obstacles is essential to enable broader commercial adoption. Ultimately, these innovations hold the potential to significantly boost the cost-effectiveness, reliability, and sustainability of solar thermal technologies, contributing to a faster global transition toward renewable energy sources.

Thermally-enhanced nanoencapsulated phase change materials for latent functionally thermal fluid

A Nano-Encapsulated Phase-Change Material (NEPCM) suspension is made of nanoparticles containing a Phase Change Material in their core and dispersed in a fluid. These particles can contribute to thermal energy storage and heat transfer by their latent heat of phase change as moving with the host fluid. Thus, such novel nanoliquids are promising for applications in waste heat recovery and thermal energy storage systems. In the present research, the mixed convection of NEPCM suspensions was addressed in a wavy wall cavity containing a rotating solid cylinder. As the nanoparticles move with the liquid, they undergo a phase change and transfer the latent heat. The phase change of nanoparticles was considered as temperature-dependent heat capacity. The governing equations of mass, momentum, and energy conservation were presented as partial differential equations. Then, the governing equations were converted to a non-dimensional form to generalize the solution, and solved by the finite element method. The influence of control parameters such as volume concentration of nanoparticles, fusion temperature of nanoparticles, Stefan number, wall undulations number, and as well as the cylinder size, angular rotation, and thermal conductivities was addressed on the heat transfer in the enclosure. The wall undulation number induces a remarkable change in the Nusselt number. There are optimum fusion temperatures for nanoparticles, which could maximize the heat transfer rate. The increase of the latent heat of nanoparticles (a decline of Stefan number) boosts the heat transfer advantage of employing the phase change particles.

Graphene/SiO2/n-octadecane nanoencapsulated phase change material with flower like morphology, high thermal conductivity, and suppressed supercooling

Heat transfer enhancement of nano-encapsulated phase change material (NEPCM) using metal foam for thermal energy storage