Application Of Phase Change Materials Research Articles

A review on phase change material's applications in solar parabolic dish collectors

A review on phase change material's applications in solar parabolic dish collectors

Experimental analysis of the influence of PCM on the thermal behavior of lightweight buildings in different natural environments

Phase-change materials (PCM) can effectively improve the thermal performance of lightweight buildings, but their heat storage and release capacity are highly dependent on the heat exchange between the wall surface and the ambient environments. However, the current research mostly focuses on numerical simulation in a specific climate environment, and the effectiveness of PCM on the thermal regulation of lightweight buildings under a long-period natural environment is insufficient. Therefore, two experimental rooms (with and without PCM) of the same size were built and conducted in this paper to compare the changing rules of wall surface temperature, heat flux, and indoor temperature in different seasons without mechanical equipment. The results show that: (1) The effect of PCM on the thermal performance of lightweight buildings is highly correlated with seasons, and its contribution efficiency varies in different seasons; (2) The attenuation rate of the internal surface temperature in different seasons can be reduced by 18.08%–42.90 %, the delay time can be improved to 2.67–4 h compared with the reference wall; (3) PCM can effectively inhibit the fluctuation and rise of indoor temperature, which can reduce the maximum indoor temperature by 4.9–12.0 °C, increase the minimum temperature by 1.1–2.8 °C, and the thermal comfort hours added by 2–5 h; (4) Lightweight buildings incorporating PCM can saves 18.69 % and 49.63 % for the peak cooling in summer and transition seasons, and 15.9 % for the heating in winter. The research results can provide the theoretical basis and experimental support for the efficient application of PCM in lightweight buildings.

The innovative application of phase change materials in heat storage products: warmer pads

As the issue of energy shortage becomes increasingly severe, energy storage technology has gradually attracted global attention, with the application of phase change materials (PCMs) being particularly widespread. This paper focuses on a common daily product: the warmer pad, and investigates the selection and ratio of suitable PCMs to achieve a recyclable heat storage solution. The study first outlines the research background, significance, and methods, then summarizes the basic principles of phase change and the role of differential scanning calorimetry (DSC) in the study of phase change heat storage. Finally, the properties of PCMs with different proportions were tested, and the DSC curves were analyzed. The results showed that the phase change material mixture with a ratio of paraffin: OBC: expanded graphite = 77:20:3 exhibits excellent performance in heat storage, with a thermal conductivity of 0.547 W/mK, a phase change latent heat of 150 J/g, and a phase change temperature of 41.9C. The warmer pad achieved a surface temperature close to 40C and a heat release duration of nearly one hour. This study aims to promote the industry's transformation towards sustainable development and provide a reference for research in the field of daily-use products with phase change heat storage.

The State of the Art on Phase Change Material-Modified Asphalt Pavement

During the construction and maintenance of asphalt pavement, a lot of non-renewable resources are consumed, which discharge a variety of waste gasses and smoke, causing a serious impact on the environment. Reducing society’s reliance on non-renewable resources is therefore key to improving sustainability. It is found that phase change materials (PCMs), as environmentally friendly materials, can spontaneously store and release heat energy by changing the phase state, thus reducing the adverse effect of temperature on asphalt pavement, reducing the occurrence of high-temperature stress, minimizing the cost of road construction and maintenance, and saving resources. In order to promote the application of PCMs in asphalt pavement, to promote self-controlling temperature technology for asphalt pavement, and to improve the sustainable development of asphalt pavement, this paper reviews the research status of PCMs in asphalt pavement, both domestically and abroad. The results show that the thermal conductivity of the modified asphalt binder can reach 0.29–0.39 W/mK, and the thermal diffusivity can reach 0.2–0.3 mm2/s, but the influence on the viscosity of the asphalt is limited, and both are less than 2000CP. The durability and thermal stability of the modified asphalt mixture are improved, and the maximum temperature can be lowered by 9 °C, which effectively reduces the occurrence of hightemperature stress. This review will help to better understand the function of PCMs and promote the sustainable development of green and environmentally friendly asphalt pavement.

Optimizing passive energy savings in rural self-built houses: Integrating phase change materials across China's climate zones

The energy consumption of rural residential buildings in China is increasing, and the integration of phase change materials (PCMs) has emerged as an effective strategy to mitigate building energy use and carbon emissions. Given China's diverse climate zones and the varying construction forms of rural self-built houses (RSHs), the efficacy of PCM applications varies significantly across regions. This study presents a comprehensive investigation into passive energy savings using PCMs in RSHs across various climate zones. We investigate the energy saving potential and thermal comfort effects of installing PCMs with varying phase change temperatures and thicknesses at different laying positions in representative buildings from each climate zone. The results indicate that the optimal phase change temperatures in different regions closely align with the outdoor average temperatures during the application season. When the optimal phase change temperatures and appropriate thicknesses of PCM are applied, cost-effective energy savings are consistently achieved in building roofing across regions, with the most significant effects observed in the Severe Cold region, where the uncomfortable degree hours reduction rate (φUDH) exceeds 90 %.

Numerical investigation on the heat dissipation of phase change materials used in the high-speed train brake system

The massive heat dissipation demands of the brake system in high-speed trains pose a significant obstacle to achieving higher operation speeds. Phase change material has attracted considerable attention in various fields due to their exceptional heat dissipation capabilities, yet their utilization in the brake system of high-speed trains remains unexplored. This study aims to investigate the feasibility of phase change material application in the brake system of high-speed train. Specifically, in Case A, the introduction of phase change material resulted in a notable 21% decrease in the average temperature and a remarkable 40% reduction in the maximum temperature difference within the brake system. The latent heat of the phase change material plays a crucial role in maintaining a substantial temperature differential between the cooling components and discs, thereby enhancing heat flux in the brake system. Phase change materials exhibit superior cooling performance compared to traditional air cooling methods in the brake system. To expedite the cooling process of phase change material and facilitate its transition from liquid to solid, an optimized brake system structure utilizing phase change material was proposed. This optimized design holds promise in enhancing the overall heat dissipation efficiency of the high-speed train brake system.

Numerical and experimental study of thermal stabilization system for satellite electronics with integrated phase-change capacitor

In this paper experimental and numerical investigations were conducted to analyze the application of phase change material (PCM) for temperature stabilization of small satellite electronics. The reference electronic equipment is a data processing unit generating a nominal power of 9.6 W during its operation. To stabilize its temperature, an integrated PCM module was designed, built, and tested experimentally in a thermal–vacuum chamber. The experimental results were then used to validate a numerical model, developed using commercial software Simcenter FloEFD. The results showed good agreement between measured and predicted temperature evolution in critical locations of the unit. The model predictions were further improved by conducting analysis of uncertain input data, model settings, and by inclusion of the effect of natural convection in the PCM. The improved model showed better agreement between the model predictions and experiments. The comparison showed that the maximum difference between the measured and calculated temperature at the most important location (the heater) was 1.6 °C and difference of the peak values was 0.8 °C. Finally, the model was used to compare the constructed module containing the PCM with a system consisting of an aluminum block of the same volume as PCM. The comparison showed that the use of PCM allows for a reduction of the maximum temperature by 6.2 °C while reducing the mass almost 3.5 times. The results demonstrate that the developed numerical model allows for accurate predictions of temperature distributions in the designed device, and can be effectively used to design PCM modules dedicated to in-space electronics, thereby increasing their peak capabilities and lifetime.

Phase change materials as hydrogen explosion suppressants: An experimental and kinetic investigation

To investigate the potential application of phase change materials as H2 explosion suppressants, in the present work, the inhibition effect of Na2HPO4·12H2O, K2HPO4·3H2O, and Na2CO3·10H2O on H2 explosion were experimentally studied. The corresponding explosion suppression mechanism was calculated by using a comprehensive combustion model. Results showed that the selected phase change materials inhibited the H2 explosion, and Na2CO3·10H2O has the most significant effect for fuel-lean H2-air mixtures when 12 g was added. Of which the maximum explosion pressure (Pmax) and maximum rate of pressure rise (dp/dt)max were reduced by 26.6 % and 28.1 %, and maximum pressure increase time (tb) and peak pressure time(tc) were increased by 112.2 % and 120.3 %. The inhibition mechanism of Na2CO3·10H2O on H2 was revealed by numerical simulation. The adiabatic flame temperature (AFT) and laminar burning velocity (LBV) of H2-air mixture decrease with increasing hydrated salt addition, the free radicals H, O and OH have a decisive influence on the explosion process during which H decreases by 86.4 % at most. The chain initial reaction O + H2 ⇌ H + OH and the sodium-containing primitive reaction NaO + H + M ⇌ NaOH + M have the most significant influence on the combustion processes. The results of present work give a theoretical foundation for application the phase change materials in H2 explosion safety industry.

A Review of the Energy-Saving Potential of Phase Change Material-Based Cascaded Refrigeration Systems in Chinese Food Cold Chain Industry

As the global demand for food increases, the efficiency and environmental sustainability of refrigeration systems have become increasingly critical issues. Cascaded refrigeration systems (CRSs) are widely used in the Chinese food cold chain due to their capacity to meet a wide range of temperature requirements. However, energy consumption of these systems is always high. If phase change materials (PCMs) are combined with the refrigeration systems, the energy-saving effect is remarkable. The paper reviews the integration of PCMs within CRS, focusing on their potential to reduce energy consumption, thereby improving food safety and reducing reliance on conventional, electricity-intensive refrigeration methods. The study categorizes and explores the low-temperature applications of PCMs in CRS, providing novel insights into enhancing energy efficiency in food cold chain logistics. Despite most PCM research focusing on single-stage systems, this review innovates by introducing PCM integration in multistage cascade systems, which is particularly relevant for low-temperature requirements. The discussion encompasses the structure, working fluids, and applications of CRSs in the cold chain, emphasizing the role of PCMs in sustainable cold chain management. The review concludes by highlighting the need for further research on PCMs in CRS, especially regarding their economic viability and large-scale implementation potential.

A novel application of waste poplar sawdust biochar: preparation of a shape-stable composite phase-change material with excellent thermal energy-storage performance

ABSTRACT The practical application of phase-change materials (PCMs) is limited due to leakage and low thermal conductivity. In this study, waste poplar sawdust (PW) and its derived biochar (PWC) were used as encapsulation materials, with stearic acid (SA) as the phase-change material, to successfully prepare composite phase-change materials with no leakage and high thermal conductivity. The microstructure and pore structure of PW and PWC were studied through SEM and nitrogen adsorption–desorption curves. The analysis results of FTIR, XRD and TGA indicated SA/PW and SA/PWC had excellent chemical compatibility and thermal stability. Excitingly, compared to SA/PW, SA/PWC exhibited higher latent heat and thermal conductivity. DSC results showed that the phase-change latent heat of SA/PWC can reach 100 J/g, which was 21% higher than that of SA/PW and the thermal conductivity increased by 87% times compared to SA/PW . In addition, SA/PW and SA/PWC still exhibited good thermal energy storage capacity after 200 thermal cycles. This research not only effectively resolved the leakage and low thermal conductivity challenges associated with PCMs but also introduced a novel utilization strategy for waste poplar sawdust, thereby significantly expanding its application potential.

NiCo@EG-based composite PCMs with boosted thermal conductivity and photothermal conversion efficiency for solar energy harvesting

The application of phase change materials (PCMs) in solar energy is hampered by challenges such as insufficient photothermal conversion efficiency, low thermal conductivity and leakage. In this study, a novel composite PCMs based on NiCo@EG were prepared to solve the problems of low thermal conductivity, high leakage rate and inefficient photothermal performance. The NiCo@EG is obtained through calcination of the product of Ni-Co-BTC in-situ on expanded graphite (EG). In the composite PCMs, the octadecanol (OD) acts as a latent heat storage unit, the EG retains its porous network structure as an encapsulating skeleton. The nickel and cobalt nanoparticles derived from Ni-Co-BTC bimetallic organic frameworks are uniformly fixed on the surface of the EG, which could not only construct multiple thermal conduction pathways, but also enhance the photon-trapping ability. Benefiting from the synergy effect of nickel, cobalt metal nanoparticles and EG, the prepared OD/NiCo@EG-550 composite PCMs display high latent heat (168.3 J/g), excellent photothermal conversion efficiency (98.71 %), and improved thermal conductivity of 12.873 W/(m·K). Furthermore, the composite PCMs demonstrate exceptional shape stability, thermal stability, and robust thermal reliability. In summary, the high-efficiency photothermal composite PCMs display significant potential in improving the utilization of solar energy.

Numerical study on the combined application of multiple phase change materials and gradient metal foam in thermal energy storage device

Latent heat thermal energy storage (LHTES) offers significant energy-saving benefits, but its application is limited due to the low thermal conductivity of phase change material (PCM). To address this issue, this article studied the combined application of metal foam structures with different porosity gradients and multiple PCMs with different melting points through numerical simulation to accelerate the melting of PCM and enhance system efficiency. The results showed that the application of multiple PCMs improved the heat transfer performance of the system, reducing the complete melting time by 9.18% compared to using a single PCM with uniform metal foam. Based on the multi-PCM storage system with an average porosity of 0.90, this article designed metal foam structures with one-dimensional and two-dimensional porosity gradients and explored their impacts. The results indicated that in the structure with a one-dimensional porosity gradient along the heat flow direction, the positive gradient decreased thermal resistance, further reducing the complete melting time by 6.18%, while the negative gradient increased it by 19.78%. However, the temperature non-uniformity was lowest with the negative gradient and highest with the positive gradient. The optimal two-dimensional porosity gradient multi-PCM storage model not only reduced thermal resistance but also effectively solved the issue of uneven melting, reducing the complete melting time by 17.96% and increasing the energy storage efficiency by 20.16% compared to the single PCM system with uniform porosity. Furthermore, the article conducted a dimensionless analysis of the optimal structure and different gradient structures, establishing formulas for the liquid fraction concerning modified Fourier number, modified Stefan number, and modified Rayleigh number.

Light/electro-thermal conversion of carbonized sweet potato 3D grid-supported PEG shape-stable phase change materials for thermal management applications

Phase change materials (PCMs) are functional energy-storage materials that achieve reversible heat storage and release through phase transition processes. They have extensive applications in the thermal management and solar energy industries. However, their low electrical and thermal conductivities and poor stability often fail to meet application requirements. In this study, we utilised an abundant biomass-derived carbon source, sweet potatoes, to prepare a three-dimensional network of carbon aerogels. By simply vacuum-impregnating polyethylene glycol (PEG), the PCM was embedded in the carbon aerogel. The obtained PEG/carbon aerogel composite material exhibited high enthalpy (158.1 J/g) and good thermal and shape stability. They also demonstrated efficient photothermal (88.47 %) and electrothermal conversion (94.02 %). This research has significant potential for applications in solar energy storage and utilisation, building energy storage, space–ground thermal energy storage, and electronic device thermal management. This study provides a novel approach for the preparation and photothermal applications of bio-based PCMs.

Thermal management of counter terminal lithium-ion battery using Bio-based PCM

Research interest in applying Phase Change Materials (PCMs) for thermal management has been evident across various applications. In several studies, researchers have also suggested the use of PCMs for thermal management in lithium-ion batteries. The current study focuses on thermal management of lithium-ion batteries with terminal configurations positioned in a counter layout, comparing scenarios with and without the implementation of Bio-based PCM. Analysis has been conducted at various discharge rates (1C, 5C, and 10C) using the MSMD model in ANSYS Fluent software for transient analysis. Thermal performance has been numerically evaluated by analyzing temperature, voltage, and PCM’s liquid fraction. The results show that counter terminal lithium-ion batteries exhibit more uniform heat distribution compared to those with terminals in parallel configuration. At a 1C discharge rate, the maximum temperature peaks at 326.15 K, demonstrating a notable 6.23 % reduction with PCM integration. Similarly, at 5C and 10C discharge rates, the maximum temperatures peaks at 346.54 K and 372.99 K, respectively, witness reductions of 10.16 % and 12.44 % due to PCM utilization. Furthermore, the application of PCM facilitates a uniform drop in voltage during discharge, enhancing overall battery performance and longevity.

Experimental and numerical performance analysis of an active cooling wall module equipped with micro-encapsulated phase change material

The application of phase change materials (PCMs) combined with radiant cooling systems (RCS) in the building sector has attracted enormous interest in recent years owing to its thermal storage potential and feasibility for small-scale energy renovation of existing buildings. Different configurations of these systems and their performance have been experimentally tested and academically investigated. The present study experimentally tested a newly conceived PCM-equipped modular cooling wall and evaluated the impact on thermal performance under different feed water temperatures and PCM concentrations using numerical methods. From the parametric study, we found that the feed water temperature, in comparison to the PCM concentration, is the dominant factor influencing cooling power and the final radiant surface temperature of the wall module. During charging, these two factors impact the time constant τ95 much more than τ63. Comparing the time required for the wall surface to reach the set reference temperature of 23 C∘ during discharging, it takes 2.37 times longer in the 30% PCM scenario than in the scenario without PCM when the feed water temperature is 5 C∘. If the feed water temperature increases to 10 and 15 C∘, this factor changes to 1.88 and 0.59, respectively. Taken together, the results were intended to optimize the design and definition of the PCM-RCS configuration for various usage scenarios.

An Innovative Heating Solution for Sustainable Agriculture: A Feasibility Study on the Integration of Phase Change Materials as Passive Heating Elements

In this study, we investigate an innovative option for the ecological management of agricultural land. The focus is on the use of phase change materials (PCMs) for passive temperature regulation in greenhouses and fruit crop fields in order to reduce yield losses due to unforeseen late frost events. The use of PCMs represents a novel approach to enhancing crop growth and extending growing seasons without relying on conventional energy-intensive methods, providing a stable microclimate that can protect plants from cold stress. This passive regulation of temperature helps to reduce the need for fossil fuel-based heating systems, thereby lowering greenhouse gas emissions and operational costs. The application of PCMs in agricultural settings is particularly innovative as it leverages naturally occurring temperature variations to create a self-sustaining, low-maintenance solution that aligns with the principles of sustainable farming. This approach not only improves energy efficiency but also contributes to the resilience of agricultural practices in the face of climate variability. This study focuses on the possible use of PCMs in passive heating modules for the protection of potted plants in greenhouses. Various PCMs such as paraffin, beeswax, and shea butter were tested. Experiments were then conducted, using one kind of paraffin-based PCM, in a specially designed module. In addition, an FEM simulation model (CFD) was built and tested. The model was used to perform detailed analyses of the heat transfer efficiency, fluid dynamics, and overall performance of the modules. The model can also be used for optimization purposes (e.g., efficiency improvements).

Phase change materials encapsulated in graphene hybrid aerogels with high thermal conductivity for efficient solar-thermal energy conversion and thermal management of solar PV panels

Phase change materials (PCMs) have a wide range of applications in latent heat storage and thermal management. However, their practical use is hindered by high leakage rates and low thermal conductivity. To address these issues, polyvinyl alcohol/carboxylated carbon nanotubes/graphene hybrid aerogels (PCG) were carbonized at high temperatures to obtain polyvinyl alcohol/carboxylated carbon nanotubes/graphene carbon aerogels (cPCG). Polyethylene glycol (PEG) was then encapsulated within cPCG to form cPCG@PEG shape-stabilized PCMs (SSPCMs). These cPCG@PEG SSPCMs demonstrated excellent thermal conductivity (0.843 W•m-1•K-1) and superior solar-thermal conversion performance (91.8%). Additionally, the latent heat of cPCG@PEG showed a minimal decrease even after 100 melt-crystallization cycles. An experimental setup was designed to regulate the temperature of solar photovoltaic (PV) panels using cPCG@PEG. The results indicated that cPCG@PEG effectively managed the temperature of solar PV panels under varying light conditions. This study presents a novel approach for enhancing the application of porous PCMs in solar energy utilization and thermal management of equipment.

Study on Thermophysical Properties and Phase Change Regulation Mechanism of Optically-Controlled Phase Change Materials: Synthesis, Crystal Structure and Molecular Dynamics.

Optically-controlled phase change materials, which are prepared by introducing molecular photoswitches into traditional phase change materials (PCMs), can convert and store solar energy into photochemical enthalpy and phase change enthalpy. However, the thermophysical properties of optically controlled PCMs, which are crucial in the practical, are rarely paid attention to. 4-(phenyldiazenyl)phenyl decanoate (Azo-A-10) is experimentally prepared as an optically-controlled PCMs, whose energy storage density is 210.0 kJ·kg-1, and the trans single crystal structure is obtained. The density, phase transition temperature, thermal conductivity, and other parameters in trans state are measured experimentally. Furthermore, a microscopic model of Azo-A-10 is established, and the thermophysical properties are analyzed based on molecular dynamics. The results show that the microstructure parameter (order parameters) and thermophysical properties (density, radial distribution function, self-diffusion coefficient, phase change temperature, and thermal conductivity) of partially or completely isomerized Azo-A-10, which are challenging to observe in experiments, can be predicted by molecular dynamics simulation. The optically-controlled phase change mechanism can be clarified according to the differences in microstructure. The optically-controlled switchability of thermophysical properties of an optically-controlled PCM is analyzed. This study provides ideas for the improvement, development, and application of optically-controlled PCMs in the future.

Phase Change Materials for Applications in Building Thermal Energy Storage (Review)

Phase Change Materials for Applications in Building Thermal Energy Storage (Review)

Novel modular PCM wall board for building heating energy efficiency: Material preparation, manufacture and dynamic thermal testing

With the comprehensive implementation of China’s “dual carbon” goals, the building heating sector, characterized by high energy consumption and emissions, urgently requires low-carbon transformation. However, energy-saving measures for plateau regions are scarce and face challenges due to harsh climates. This study proposes an innovative heating method utilizing composite phase change materials. A new modular phase change thermal storage electric heating terminal integrated with a photovoltaic thermal system has been designed to address issues of high building energy consumption and problems related to heating system freezing and leakage in the Tibetan Plateau (Qinghai-Xizang Plateau). Laboratory tests were conducted on six groups of samples with different structures and placements to examine their heat storage and release characteristics. Results indicate: The system’s temperature stabilization time totals 14.6 h; Horizontally placing the terminal reduces melting time by up to 2.7 h, enhancing heat storage performance; Structure three shortens solidification time by up to 2.2 h compared to structure one, improving heat release performance; Vertically placed terminals have better heat release performance than horizontally placed ones, resulting in more effective indoor heating. This study proposes a modular design for phase change heat storage electric heating walls, simplifying installation and maintenance while maintaining aesthetic appeal. Detailed temperature measurements of different wall surfaces revealed excellent cyclic heat storage and release performance. The developed phase change heat storage electric heating terminal is expected to significantly reduce heating energy consumption in the Tibetan Plateau (Qinghai-Xizang Plateau), enhancing building energy efficiency and providing valuable insights for further applications of phase change materials in building design.