Performance Of Phase Change Materials Research Articles

Laboratory Experiments on Passive Thermal Control of Space Habitats Using Phase-Change Materials

Here, we investigate the performance of phase-change materials (PCMs) in the passive thermal control of space habitats. PCMs are able to absorb and release large amounts energy in the form of latent heat during their (typically, solid-to-liquid) phase transition, which makes them an ideal choice for passive temperature control. In this study, a conceptual design of an igloo-shaped habitat is proposed. A scaled model for laboratory experiments is manufactured via 3D printing, using tap water as the PCM. The setup is used to conduct experiments and analyze PCM performance, based on temperature measurements inside and outside the habitat. Results demonstrate the effectiveness of PCMs in increasing thermal inertia and stabilizing the habitat interior temperature around the melting temperature, confirming that PCMs can be a suitable alternative for passive thermal control. The present study holds significant interest for the future of space exploration, with the emerging need to design habitats that are capable of accommodating astronauts.

Systematic review of the use of phase change material (PCM) in concrete and the fire performance of PCM in concrete

ABSTRACT The Mechanical properties of concrete significantly deteriorate when exposed to fire, with explosive spalling posing a major threat to structural integrity. This highlights the need for effective insulation systems to protect concrete structures in fire conditions. However, current insulation solutions are typically installed externally, requiring additional labour and materials. This review explores the potential of incorporating Phase Change Materials (PCMs) directly into concrete as an embedded insulation system. As a latent heat storage material, PCM offers promising fire-resistant properties, reducing the need for external insulation while improving the fire performance of concrete. This paper presents a bibliometric analysis and a systematic review of recent publications on the use of PCMs in concrete and their fire performance applications. One thousand two hundred and four publications retrieved from Scopus© and Web of Science databases were passed through the PRISMA flowchart to obtain a database of recent literature on the study area. The current trend of research shows a shift towards inorganic PCMs in concrete. There is a significant lack of studies on using inorganic and eutectic PCM in concrete for fire applications and existing studies show inorganic PCM can be a viable solution. Commercial availability and lack of synthesised encapsulated PCM were found to be barriers to research.

Development, characterization and themo-physical analysis of energy storage material doped with TiO2 and CuO nano-additives

The paper presents the results of an experimental investigation on chemical stability, surface morphology, and thermo-physical properties of phase change material integrated with nano additives. The research aims to evaluate impact of varying nano-particle concentration on thermal performance of phase change material. The phase change material magnesium dichloride hexahydrate and potassium chloride mixed in different mass ratio along with different wt% concentration of nano-additives titanium dioxide and copper oxide to prepare novel phase change material. Characterization methods such as Fourier Transform Infrared Spectroscopy, Scanning electron microscope, Energy-dispersive X-ray analysis, and Differential scanning calorimeter analysis were employed. The Fourier transform infrared spectra indicated physical interactions between phase change material and nano-additives, while Energy-dispersive X-ray analysis confirmed elemental composition, and Scanning electron microscope demonstrated uniform distribution. The improved thermal properties of samples were reflected in their phase change enthalpy (284.57 J/g to 324.63 J/g), minimal energy loss (0.91 %–2.96 %), and low supercooling (0.3 %–5.26 %). Notably, doping with 1.5 wt% of titanium dioxide and copper oxide enhanced thermal conductivity by up to 117.07 % and specific heat capacity by up to 48.09 %. The introduction of nanoparticles significantly improves heat transfer characteristics, resulting in enhanced energy retention, reduced energy loss during phase transitions, decreased supercooling, and increased physical stability. These results suggest that optimized phase change material with nano-additives is highly effective for applications requiring stable and efficient thermal management.

Phase Change Material Performance in Chamfered Dual Enclosures: Exploring the Roles of Geometry, Inclination Angles and Heat Flux

Phase Change Material Performance in Chamfered Dual Enclosures: Exploring the Roles of Geometry, Inclination Angles and Heat Flux

An experimental and numerical investigation of the thermal performance of phase change materials in different triple-glazed window configurations

Phase Change Materials (PCM) may be excellent thermal insulation due to their poor conductivity and high heat capacity. Researchers are adding PCM to windows. This integration modifies internal surface temperatures and delays peak temperatures to improve indoor thermal comfort. This work investigates experimentally and numerically the impact of the different filling materials in four Triple Glazed Windows (TGW) configurations in an Iraqi environment: the first window filled two cavities with air (standard); the second window has one cavity filled with a PCM and the other with air; the third window has blinders with various tilt angles in one cavity and PCM in the other cavity; and in the fourth window, both cavities are filled with PCM. Numerically utilizing Computational Fluid Dynamics to evaluate the thermal performance of TGW. In August, when the solar radiation was at its maximum (623 W/m2), the results showed that the peak interior surface temperature dropped by 4.51, 13.28 and 11.53 % in the TGW configurations (PCM-air), (blinder-PCM), and (PCM-PCM), compared to the standard TGW. The fourth window increased the time lag by 2 h, effectively shifting the load and in the third window, the best tilt angle blinder is 45°

Numerical Study on the Effect of Heat Source and Fin Arrangement on the Melting Performance of Phase Change Materials in a Latent Heat Storage System

Numerical Study on the Effect of Heat Source and Fin Arrangement on the Melting Performance of Phase Change Materials in a Latent Heat Storage System

Thermal performance investigation of microencapsulated phase change material enhanced with graphene nanoplatelets in double-glazing applications

Effective heat energy storage is crucial for thermal energy management. The utilization of latent heat storage methods is widely prevalent across various engineering applications for enhancing energy efficiency. In this study, the energy storage performances of Phase Change Materials (PCMs) achieved by incorporating graphene nanoplatelets into a microencapsulated PCM were experimentally analyzed for double-glazing applications. Changes in thermal energy storage and heat transfer performance by incorporating graphene nanoplatelets into the PCM at two different mass ratios (1 % and 0.1 %) were investigated. The results obtained from light intensity and temperature measurements, as well as thermal camera imaging, were evaluated together. The results support the contribution of graphene nanoplatelets addition to microencapsulated PCMs in enhancing thermal performance during both heating and cooling periods. Among the investigated cases, the highest mass ratio of 1 % graphene nanoplatelets addition led to a major 10 °C increase in peak temperature compared to the reference condition. In contrast, this increase in peak temperature was accompanied by a mere 14 % decrease in average light levels. This research underlines the potential of graphene-enhanced microencapsulated PCMs in optimizing thermal management systems for double-glazing applications, offering a promising pathway towards enhancing energy efficiency and thermal comfort in building environments.

Recent Progress of Phase Change Materials and Their Applications in Facility Agriculture and Related-Buildings—A Review

Facility agriculture, which involves agricultural production in controlled environments such as greenhouses, indoor farms, and vertical farms, aims to maximize efficiency, yield, and quality while minimizing resource consumption and environmental impact. Energy-saving technologies are essential to the green and low-carbon development of facility agriculture. Recently, phase change heat storage (PCHS) systems using phase change materials (PCMs) have gained significant attention due to their high thermal storage density and excellent thermal regulation performance. These systems are particularly promising for applications in facility agriculture and related buildings, such as solar thermal utilization, greenhouse walls, and soil insulation. However, the low thermal conductivity of PCMs presents a challenge for applications requiring rapid heat transfer. This study aims to provide a comprehensive review of the types, thermophysical properties, and various forms of PCMs, including macro-encapsulated PCMs, shape-stabilized PCMs, and phase change capsules (PCCs), as well as their preparation methods. The research methodology involves an in-depth analysis of these PCMs and their applications in active and passive PCHS systems within facility agriculture and related buildings. The major conclusion of this study highlights the critical role of PCMs in advancing energy-saving technologies in facility agriculture. By enhancing PCM performance, optimizing latent heat storage systems, and integrating intelligent environmental control, this work provides essential guidelines for designing more efficient and sustainable agricultural structures. The article will serve as the fundamental guideline to design more robust structures for facility agriculture and related buildings.

Optimizing the thermal performance of phase change materials in building applications using deep reinforcement learning and Bayesian optimization

This research presents a novel methodology for Deep Reinforcement Learning (DRL) and Bayesian Optimisation of the thermal performance of PCMs in building operations. The developed models utilise a unique and large dataset comprising 1500 building thermal profiles, simulated for various climates and building setups obtained from our industry partners and as open data. PCM-based systems are deployed for thermal insulation of building envelopes to regulate indoor temperature conditions and reduce the need for heating and cooling systems, resulting in enhanced energy efficiency. Through the real-time management of the thermal efficacy of PCMs using the DRL method trained on the large dataset and fine-tuning of the underlying model parameters using Bayesian Optimisation, the optimised system achieves energy saving in heating and cooling load of up to 45 percent, along with the induced reduction in CO2 emission. At the same time, DRL contributes to decreasing the thermal fluctuation in the indoor temperature and keeps it in the narrow range of 1.2 °C in case of high thermal variability scenarios. Currently, the best performance is reported in the literature. This research exemplifies the potential of DRL and Bayesian optimisation in sustainable building. It depicts the applications of advanced intelligent computing algorithms with big building energy data as a novel, robust and superior approach for optimising real-world building energy management systems. The methodology and the improvements in energy savings in thermal and energy management of buildings highlight the novelty and potential benefit of the implemented research as a new intellectual property towards sustainable building design.

Effect of nanomaterials on the melting/freezing characteristics of phase-change material

A novel variant of composite phase-change material (PCM) was developed by incorporating 0.5 wt% aluminum oxide (Al2O3), silicon dioxide (SiO2), copper (II) oxide (CuO) and silver (Ag) nanomaterials into myristic acid. In this formulation, myristic acid served as the foundational material, while aluminum oxide, silicon dioxide, copper (II) oxide and silver were employed as supporting components. The morphology and crystalline structure of the nanomaterials were studied using field-emission scanning electron microscopy and X-ray diffraction analysis, respectively. The composite PCMs were fabricated using a two-step process. The phase-change properties of the composite PCMs were assessed using differential scanning calorimetry. The nanomaterials (0.5 wt% aluminum oxide, silicon dioxide, copper (II) oxide and silver) were suspended in myristic acid separately to investigate the heat-transfer performance of the composite PCMs during phase-change processes (melting and freezing). The results clearly indicated that the duration of the melting and freezing processes of the composite PCMs decreased compared with that of the pure PCM. Thus, the newly prepared composite PCMs are potential candidates for harvesting solar energy for low-temperature heating applications.

Advancements in Phase Change Materials: Stabilization Techniques and Applications

Phase Change Materials (PCMs) are innovative materials that absorb and release thermal energy during phase transitions, making them ideal for thermal energy storage applications. This paper provides a comprehensive overview of PCMs, focusing on their functioning mechanisms, classifications, and shape stabilization methods. PCMs operate by storing latent heat during melting and releasing it upon solidification, thereby maintaining a stable temperature during phase changes. They are classified into three main categories: organic, inorganic, and eutectic. Organic PCMs, such as paraffins and fatty acids, offer high latent heat storage but suffer from low thermal conductivity. Inorganic PCMs, including salt hydrates and metals, provide better thermal conductivity but face challenges like supercooling and corrosiveness. Eutectic PCMs, which are mixtures of compounds, offer customizable melting points and enhanced thermal properties. To address leakage and improve thermal conductivity, shape stabilization methods are employed, such as encapsulation, stabilization by porous matrix, and polymer hybridized shape stabilization. These techniques enhance the structural integrity and thermal performance of PCMs, making them more suitable for practical applications. The paper highlights the potential of PCMs to improve energy efficiency and outlines future research directions for optimizing their performance in various industries.

Thermal effect of the anisotropic metal foam on the melting performance of phase change material: A pore-scale study

Recently, metal foams have been attractive in reinforcing the heat storage process of phase change materials (PCMs) beneficial from their high thermal conductivity, interconnected structure, and large specific surface. Nevertheless, the melting of PCM is not uniform caused by convective heat transfer, so it cannot be sufficiently accelerated by a traditional isotropic metal foam. In this study, we numerically investigated the melting performance of PCM in isotropic and anisotropic metal foams. Results illustrated that the X-anisotropic structure can more efficiently enhance the melting performance as compared to the isotropic original metal foam, but the Z-anisotropic structure suppresses it. Moreover, the X-anisotropy-0.5 shows the fastest melting, its complete melting time is significantly reduced by 7.99 % compared with the original model, and its heat storage power is 8.68 % higher than the original one. Instead, the Z-anisotropic models prolong the complete melting time by 11.10 % ˗ 28.55 %. It is owing that the anisotropic structure would promote the heat transfer along one direction but suppress its vertical direction. This article provides a feasible routine to accelerate the melting of metal foam-based PCMs, thus improving the heat storage power of the latent heat thermal energy storage system.

Thermal energy storage, heat transfer, and thermodynamic behaviors of nano phase change material in a concentric double tube unit with triple tree fins

The contribution of this study is the proposal of a synergistic composite enhancement strategy involving tree fins and nanomaterials to improve the low thermal performance of phase change material (lauric acid) in a typical double tube latent heat thermal energy storage unit. The effects of nanoparticle concentrations and tree fin branching angles on the fluid dynamics, melting time, heat transfer, energy storage, and entropy generation characteristics were investigated. By employing tree fins, the melting time was respectively reduced by up to 60.20% and 36.05% compared to the finless case and the rectangular fins, while the energy storage power was respectively boosted by up to 143.36% and 37.45%. The increase of nanoparticle concentration was beneficial for melting heat transfer, and the dendritic fins with a bottom angle of 90° and a top angle of 30° yielded the highest energy storage performance. The total entropy generation of the melting process was mainly governed by the thermal entropy generation, and it showed a decreasing trend with the increase of time. In contrast to the finless configuration, the incorporation of fins diminished the integrated entropy generation value. Similarly, an elevation in nanoparticle concentration also led to a reduction of the integrated entropy generation value.

PCM as an energy flexibility asset: How design and operation can be optimized for heating in residential buildings?

In cold climates, residential buildings are often well-insulated to reduce heating costs but may lead to overheating. Incorporating Phase Change Material (PCM) into building envelope can serve as an effective measure to mitigate overheating and reduce cooling costs. However, the inappropriate incorporation of PCM in well-insulated building envelope might negatively affect the heating energy flexibility. Therefore, this paper explores the effectiveness of PCM in reducing heating costs by optimizing the PCM design and heating operation. The main objectives are to (i) quantify the performance of PCM in terms of overheating and cost savings, aligned with the recently introduced Time-of-Use (ToU) tariff and Spot pricing, (ii) identify the optimal design of PCM-incorporated building envelope, and (iii) apply a smart control with resetting temperature setpoints in-line with EN-ISO 52120-1 Standard. A multi-stage optimization process has been designed. It first identifies the optimal properties (i.e., melting temperature), position, and thickness of PCM. Secondly, it optimizes the profile of temperature setpoints, considering the seasonal thermal behavior of PCM. Co-simulation platform between IDA ICE 5.0 and Python 3.8 optimization engine is created for the heating control optimization. Results showed that PCM is more effective when incorporated into the interiors of external walls rather than in roofs. The optimal PCM design for Nordic buildings, featuring 75 mm-thick PCM with a melting temperature of 21 °C positioned within walls’ interior, has a varied impact on monthly energy savings across seasons, with a negative effect in spring and a significant positive effect in autumn. After the multi-stage optimization, the optimal scenario enables to achieve a maximum annual cost savings of 6.5 % with ToU tariff and 21.0 % with Spot pricing, while also eliminating overheating.

Investigations on the heat transfer performance of phase change material (PCM)-based heat sink with triply periodic minimal surfaces (TPMS)

During the operational process of electronic components, excessive heat generation results in significant temperature elevation. This elevated temperature poses a significant risk to their service life. Regarding the issue of efficient thermal management of electronic devices in enclosed spaces experiencing high heat flow, a thermal management scheme for electronic equipment using TPMS and a PCM-based heat sink is proposed. The apparent heat capacity method is employed to simulate the melting process of the PCM-based heat sink. The effects of structural parameters w1, w3, and C of TPMS structures on the heat transfer characteristics (including base temperature, liquid fraction, average cell temperature, and average heat transfer coefficient) of the PCM-based heat sink during the melting process are discussed. A temperature testing platform is established. Experimental research is performed to investigate the effect of TPMS structures with two different printing prototypes (Sample 1, and Sample 2) on the heat sink during the intermittent cycle. The results indicate that increasing the parameters C and w1 significantly improves the average heat transfer coefficient (HTC) of the heat sink. When C increases from 0.3 to 0.7, the average HTC increases from 307 W/(m2·K) to 358 W/(m2·K). When w1 increases from 1 to 3, the average HTC increases from 284.5 W/(m2·K) to 321.3 W/(m2·K). Sample 1, possessing superior thermal conductivity, exhibits better heat transfer performance. When the temperature achieves a stable periodic variation, the base temperature of Sample 1 stabilizes within the range of 310 K-340 K. And Sample 2 stabilizes within the range of 315 K-350 K.

Melting performance of PCM with MoS2 and Fe3O4 nanoparticles using leaf-based fins with different orientations in a shell and tube-based TES system

Phase change materials (PCMs) are frequently utilized in the thermal sector, especially for thermal energy storage (TES) applications. The purpose of this study was to analyze the thermal efficiency and melting characteristics of a leaf-vein-shaped fin in a triplex tube heat exchanger. The analysis focused on the use of pure molten salt PCM and a combination of molten salt PCM with MoS2 and Fe3O4 nanoparticles. The study utilized ANSYS Fluent software to conduct numerical simulations and analyze seven distinct fin arrangements. The simulations were employed to visualize and examine the liquid fraction, temperature, and fluid velocity. The findings indicated that the leaf-vein fin shape greatly improved the dispersion of liquid fraction, average temperature, and velocity in comparison to alternative fin designs. The addition of MoS2 and Fe3O4 nanoparticles significantly enhanced the melting and thermal characteristics of the PCM as a result of heightened thermal conductivity. This showcases the capability of the leaf-vein fin design and PCM nanocomposites to enhance the efficiency of thermal energy storage in triplex tube systems. About 2500 s PCM melt about 36% for case A, but melting rate enhance up-to 55% using nano particles. Melting rate enhance 91% in 1000 s in case of G using 8 fins as compare to case A having no fins.

Prediction of thermo-physical properties and evaluation of thermal energy storage performance of phase change materials based on silicone rubber/graphite (Q/G) composites

ABSTRACT Phase change composite materials (PCCMs) are a type of thermal energy storage system known for their high latent heat of fusion. In this study, PCCM samples based on peroxide-cured silicone rubber (Q) were prepared using a simple soaking procedure in molten Paraffin Wax (PW). At any fixed amount of peroxide, the rubber base samples were filled with varying amounts of graphite powder (G), 4 to 8 Wt.%, to improve the thermo-physical properties. The effect of peroxide and graphite content was then evaluated on the PW loading, PW leakage, and thermal storage performance of the resulting Q/G/PW composites. It was found that the highest ratio of the PW loading to PW leakage occurs at a peroxide content of 6 Wt.%. Moreover, the graphite particles demonstrate a significant role in PW trapping inside the rubber structure and lowering the PW leakage. Finally, the thermal studies showed that the Q/G/PW composite containing 6 wt.% of peroxide and 4 wt.% of graphite has the highest latent heat of 111.5 J/g with a PW loading of 15.2%. This sample also had the lowest thermal diffusivity and the slowest cooling and heating rate.

Optimization of the thermal performance of a lobed triplex-tube solar thermal storage system equipped with a phase change material

The thermal performance of a PCM-based triple-tube lobed heat exchanger storage system is here simulated and optimized, including performance improvements via lobed surfaces, Y-shaped fins, dispersed multi-walled carbon nanotubes, and metal foams, to be used in combination, or singly. Such computations are done with the finite volume method under different operating conditions. The reason behind this study is to look for solutions to improve the poor thermal performance of phase change materials (PCMs) as thermal energy storage materials, that limits their compactness and instantaneous heat stored/released. This is the first time that a throughout analysis of this aspect is presented. The result showed that higher modified Stefan number allow to improve melting time of a 50.88 %. The inclusion of lobes and fins resulted in a reduction of roughly 30.54 % in time needed for melting completion, compared to straight tubes. This reduction increases to 74.26 % when lobes are combined with both nanoparticles and metal foam, and to 73.60 % with just foam. The best solution also provides a 228.34 W mean heat rate. This study becomes an option to design tube-in-tube energy storage systems, where the best improvement is achieved by considering a lobed surface together with nano/PCM and foam, whereas the highest enhancement comes from using a metal foam.

A novel microencapsulated medium-temperature phase change material employing dicarboxylic acid for thermal energy storage

Microencapsulation enhances the performance of phase change materials (PCMs). However, the existing research on microencapsulation of dicarboxylic acids (DAs) is inadequate, with only one study dedicated to the development of microcapsules containing a low DA content and a shell that decomposes at low temperatures. In this study, glutaric acid (GA), as a representation of DA, was successfully microencapsulated with an enhanced encapsulation ratio. The results obtained by scanning electron microscopy (SEM) revealed a uniform spherical core–shell structure of the microencapsulated GA (MEGA). Fourier transform infrared spectroscopy (FT-IR) an X-ray diffractometer (XRD) analysis confirmed the absence of any chemical reaction between the core and shell materials. Additionally, differential scanning calorimetry (DSC) results demonstrated excellent heat storage. Notably, MEGA exhibited a thermal reliability index of 94.4 % after 200 accelerated thermal cycles. Thermogravimetry analyzer (TGA) results showed good thermal stability of MEGA. The dispersion stability and thermal conductivity of MEGA suspensions displayed significant enhancements compared to those of GA suspensions. Furthermore, compared with the base fluid, the MEGA suspensions with 1.0 wt%, 5.0 wt% and 10.0 wt% demonstrated reduced pumping power requirements by 16.9%, 54.6% and 70.0%, respectively. These findings suggest that MEGA holds promising prospects for applications in the medium temperature energy storage field.

Computational study on transient thermal performance enhancement of phase change materials in triplex tube heat exchanger through novel annular-finned configurations

The introduction of highly conductive media to enhance the thermal performance of phase change materials (PCM) is an efficient method to counter the inherently low thermal conductivity of PCMs while retaining its benefits. This article reports the transient thermal performance of PCM in novel finned configurations based on Triplex Tube Heat Exchangers (TTHX). The shape, size, and placement of the constituent fins in the PCM domain are varied, and their effect on the transient melting rate of PCM is studied. Two PCM formulations, RT-82 and RT-35 are evaluated. Pockets within the encapsulation geometry wherein a vortex-like melting pattern of PCM can be facilitated, are identified as factors for expediting the melting process. The best performing configuration resulted in ∼17% (RT-82) and ∼9% (RT-25) reduction in melt duration compared to the baseline configuration. The effects of gravity conditions on the PCM melt process of the best performing and baseline configurations were also studied.