Application Of Phase Change Materials Research Articles

Expression of Concern for article entitled “Potential applications of phase change materials for batteries thermal management systems in electric vehicles”

Expression of Concern for article entitled “Potential applications of phase change materials for batteries thermal management systems in electric vehicles”

Phase transition arising from order-disorder motion in stable layered two-dimensional perovskite

In recent years, organic-inorganic hybrid materials are widely designed and synthesized as switching materials for temperature response. However, due to the change of molecular arrangement inside the crystal during solid-solid phase transition, the distortion of crystal lattice and the great change of lattice parameters are often caused, which result in a poor repeatability and short life. Thus, designing phase change materials with small lattice changes helps to improve product life. In this article, a novel organic-inorganic hybrid material 3HDMAPAPbBr4 (1, 3HDMAPA is 3-(hydroxydimethylammonio)propan-1-aminium) was successfully synthesized and characterized. For 1, organic cations filled in the van der Waals gap are connected by hydrogen bonds with halogens in the two-dimensional inorganic layer, forming a stable sandwich structure. During the solid-solid phase transition driven by temperature, the changes of inorganic skeleton are relatively small, and the disorder movement of organic cations does not affect the existence of hydrogen bonds, maintaining a relatively stable crystal structure. In addition, electrical property, optical property and crystal structures are analyzed and discussed in detail. We believe that our work will contribute to the development and application of phase change materials in response materials.

Energy saving and carbon reduction of the application of phase change materials in rammed earth heritage buildings

ABSTRACT The combination of conventional thermal insulation materials and phase change materials (PCMs) was proposed without damaging the appearance of REHBs, the internal insulation measures of four types of expanded polystyrene (EPS) and six kinds of PCM boards combinations were investigated, and 19 retrofit cases were obtained. By conducting detailed simulations of energy consumption and indoor temperature for different cases at different locations, and comprehensively comparing multi-objects (energy-saving, economic and low-carbon), the energy consumption, cost recovery period and carbon reduction of these cases are compared and analyzed. The results show that Case I (only EPS) has the best energy-saving performance, economy and carbon emission reduction, Case III (EPS and PCM) is the second and Case II (only PCM) is the worst. The energy-saving rate of Case I and Case III (16 ℃) differs by 5.65%, while the cost, incremental benefit and payback period differ by 9.34%, 10.2%, and 1.57 years, respectively. Case III is a new and better passive retrofit measure of the REHB. Its energy-saving, cost and carbon reduction are only about 10% lower than that of Case I, but it has better indoor comfort. The outcomes can provide a reference for the innovative energy-saving retrofit cases for REHBs.

Research on one-dimensional phase change heat transfer characteristics based on instrument compartment structure

To address the issue of electronic equipment failure inside the instrument compartment due to aerodynamic heating during high-speed flight. Combining the heat transfer characteristics of phase change materials, a new instrument compartment structure was proposed as the research subject based on phase change materials. While studying the heat transfer characteristics of this structure, one-dimensional phase change heat transfer theoretical model was constructed based on the Lightfoot integral equation method, and the corresponding analytical solution was obtained. To explore the temperature change law of the instrument compartment structure and verify the rationality of the theoretical model, the new thermal experiment was carried out for the instrument compartment structure. Compared with the aluminum alloy instrument compartment structure, the experimental results show that the instrument compartment structure design based on phase change materials could effectively reduce the temperature of the structure itself, and the experimental data are in good agreement with the theoretical calculation results, which verified the rationality of the theoretical model and provided a scientific basis for the practical application of phase change materials in instrument compartment structures.

Integration of photo/magnetic responsive composite phase change materials with polyurethane sponge for sustainable and efficient cleanup of crude oil spills

The efficient remediation of viscous oil spills is still a global challenge in practice due to the poor fluidity caused by their high viscosity. The adsorbents with in situ heating characteristics are regard as potential candidate for rapid and efficient crude oil spills cleanup. Although solar-assisted heating is the cleanest and most energy-efficient way, the great variation of sunlight intensity with the season and location is an obstacle to its practical application. To promote oil adsorption and enhance energy utilization efficiency, we constructed a novel adsorbent with simultaneous photo/magnetic-thermal response, and importantly phase change materials (PCMs) as thermal energy storage unit were introduced into the adsorbents. The Co/CNTs with high graphitization as efficient sunlight absorbers can significantly improve the photothermal conversion capacity of the adsorbent, resulting in rapid oil adsorption under solar illumination. Besides, benefiting from the superior magnetic response of Co particles encapsulated in the carbon skeleton, the adsorbent also enables efficient oil adsorption under alternating magnetic field. Most importantly, thanks to the cross-connected network structure of CNTs derived from the carbonization of ZIF-67, the PEG was well anchored in the Co/CNTs particles, which allows the adsorbent to store thermal energy and release heat for sustained cleanup of the oil spills when the energy input is insufficient. The adsorbent integrates with superior photo/magnetic-thermal conversion and thermal storage functions provides an innovative solution for efficient and energy-saving remediation of crude oil spills and breaks new grounds of PCMs applications.

Binary eutectic phase change materials application in cooling asphalt: An assessment for thermal stability and durability

Organic eutectic phase change materials (PCM) show great promise as thermal storage agents for regulating the temperature of asphalt pavements. Assessing their aging characteristics and durability when integrated into asphalt is crucial and necessitates further in-depth research. This study evaluates the impact of aging on binders with acid/palmitic acid binary eutectic PCM (SA/PA-PCM). Aging was simulated using the rolling thin film oven (RTFO) and pressure aging vessel (PAV) devices. The current study leads to the conclusion that the use of SA/PA-PCM is promising. Specifically, the incorporation of SA/PA-PCM significantly improves the aging resistance, showcasing notable enhancements in thermal stability, fatigue performance, anti-cracking ability, and thermal regulation of asphalt. Only a 5 % decrease occurred in the melting enthalpy of the binder with 15 % SA/PA-PCM after 60 h of long-term aging (from 32.17 to 25.87 J/g), showing a stable thermal storage ability. The maximum temperature difference and lag is 9.3 °C and 46 min. respectively. To sum up, Asphalt with 15 % SA/PA-PCM surpasses other binders, displaying higher melting latent heat, reduced sulfoxide index, increased long-term aging resistance, and superior stress relaxation capabilities. This research confirms the potential of SA/PA-PCM in asphalt applications, providing a new path for durable and environmentally friendly road infrastructure.

Confined Crystallization Polyether-Based Flexible Phase Change Film for Thermal Management.

Phase change materials (PCMs) possess the potential to regulate temperature by utilizing their thermal properties to absorb and release heat. Nevertheless, the application of PCMs in thermal management is constrained by issues such as liquid leakage and limited flexibility. In this study, we propose a novel approach to address these challenges by incorporating a pore structure within nanofibers to confine the crystallization of phase change molecules, thereby enhancing the flexibility of the composite material. Additionally, inspired by the adaptive mechanisms observed in plants, we have developed a form stable PCM based on polyether, which effectively mitigates the issue of liquid leakage at higher temperatures. Despite being a solid-liquid PCM at its core, this material exhibits molecular-scale flow and macroscopic shape stability as a result of intermolecular forces. The composite film material possesses remarkable flexibility, efficient thermal management capabilities, adjustable phase transition temperature, and the ability to undergo repeated processing and utilization. Consequently, it holds promising potential for applications in personal thermal energy management.

Phase change material application in solar cooking for performance enhancement through storage of thermal energy: A future demand

Phase change material application in solar cooking for performance enhancement through storage of thermal energy: A future demand

Advancements in Nanomaterial Dispersion and Stability and Thermophysical Properties of Nano-Enhanced Phase Change Materials for Biomedical Applications.

Phase change materials (PCMs) are materials that exhibit thermal response characteristics, allowing them to be utilized in the biological field for precise and controllable temperature regulation. Due to considerations of biosafety and the spatial limitations within human tissue, the amount of PCMs used in medical applications is relatively small. Therefore, researchers often augment PCMs with various materials to enhance their performance and increase their practical value. The dispersion of nanoparticles to modify the thermophysical properties of PCMs has emerged as a mature concept. This paper aims to elucidate the role of nanomaterials in addressing deficiencies and enhancing the performance of PCMs. Specifically, it discusses the dispersion methods and stabilization mechanisms of nanoparticles within PCMs, as well as their effects on thermophysical properties such as thermal conductivity, latent heat, and specific heat capacity. Furthermore, it explores how various nano-additives contribute to improved thermal conductivity and the mechanisms underlying enhanced latent heat and specific heat. Additionally, the potential applications of PCMs in biomedical fields are proposed. Finally, this paper provides a comprehensive analysis and offers suggestions for future research to maximize the utilization of nanomaterials in enhancing the thermophysical properties of PCMs for biomedical applications.

Bis(dialkylammonium)-based hybrid organic–inorganic ionic materials as solid–solid phase change materials

The application of phase change materials (PCMs) in thermal energy storage (TES) systems is often restricted by challenges such as volume expansion, phase segregation, stability issues and potential leakage, particularly prominent in conventional solid–liquid PCMs. In response to these limitations, solid–solid PCMs have emerged as a promising alternative, garnering increasing attention. While both organic and inorganic solid–solid PCMs have been extensively studied, hybrid organic/inorganic materials represent a distinct class of solid–solid PCMs that have recently garnered significant interest due to their inherent properties such as high thermal stability, non-flammability or long cycle life. Organic-inorganic layered perovskites are emerging as potential good solid–solid PCMs as they present energetic solid–solid transitions and high thermal stability. In this work we propose the synthesis and thorough thermal characterization and cyclability of a series of new hybrid organic–inorganic ionic materials based on n-dialkylamines of different lengths (C8, C10, C12 and C18) with general formula of the type 2[(CnH2n+1)2NH2][MX4], using three different tetrachlorometalates anions ([FeCl4]2-, [MnCl4]2- and [CuCl4]2-). Among the new ionic materials prepared six of them have shown solid–solid transition enthalpies higher than 100 J/g. In particular, the 3 bearing the secondary n-dioctadecylamines as cations have shown unprecedent solid–solid transitions enthalpies ca. 90 °C, for this kind of ionic materials of 167.5 J/g, 157.7 J/g and 146.9 J/g for [DODA]2[MnCl4], [DODA]2[CuCl4] and [DODA]2[FeCl4] respectively. In addition, the latter ionic materials have undergone reliability tests showing excellent performance up to 500 heating/cooling cycles.

Thermal and electrical properties of palmitic acid/expanded graphite composite phase change materials for thermal energy storage

Expanded graphite (EG) based phase change material (PCM) has attracted significant concern in thermal management systems. In this paper, a series of composite PCMs composing of EG with different sizes (50, 80, and 100 mesh) as the substrate, and palmitic acid (PA) as the PCM, were prepared by vacuum impregnation method. The results shown that the size of EG particles effect the adsorption capacity of PA. The mass fraction of PA in PA/EG-50 reached 83.6% and the enthalpy of melting and solidification of PA/EG-50 are 160.13 J/g and 159.75 J/g, respectively. The thermal conductivity decreased slightly as the particle size of EG increased, and the thermal conductivity of PA/EG-100 is the highest of 4.86 W/(m·K). The TGA results show that all composite PCMs present good thermal stability below 200 °C. The electro-thermal conversion efficiency increased with the particle size of EG increasing, and the electro-thermal conversion efficiency of PA/EG-100 reached up to 91.39% under low-voltage conditions (1.9 V). These results throw light on the potential application of EG-based composite PCM, especially for the electro-thermal conversion.

Critical analysis of enhanced photovoltaic thermal systems: a comparative experimental study of PCM, TEG, and nanofluid applications

Phase change materials (PCM), thermoelectric generators (TEG), and nanofluids are popular methods investigated for improving conventional photovoltaic thermal (PVT) systems. These methods are particularly used in warm climates where high temperatures negatively impact photovoltaic (PV) power output and energy efficiency. This experimental study evaluated the effects of 32 °C melting point PCM and TEG integration on PVT units, as well as 42 °C melting point PCM and nanofluid incorporation on concentrated PVT (CPVT) units. Technical, exergetic, and economic performance were compared using a small-scale PVT module. Low-cost commercially available materials were used to construct all PVT units. Industrial metal waste was introduced to enhance the thermal conductivity of paraffin wax and salt hydrate PCMs. The results indicated that applying PCMs, porous media, and concentrator plates increased energy generation, potentially offsetting their higher initial cost and achieving an energy cost of approximately $0.135/kWh. However, TEG and nanofluid implementation remained uneconomical, leading to a 15–35 % increase in energy cost. The water-based CPVT unit, enhanced with paraffin wax and copper fins, demonstrated the best technical performance. This unit achieved electrical, thermal, and exergy efficiencies of approximately 15.5 %, 37.4 %, and 16.7 %, respectively, with more than a 20 % reduction in cell temperature. The study also revealed that severe structural changes caused by corrosion of metallic materials in hydrated PCMs could alter the melting point by more than 30 %. This change negatively impacts heat storage capacity. Conversely, incorporating metal chips in non-hydrated PCMs improved the time to reach the melting point state by 30–60 minutes.

Thermal Performance of Heat Sink Filled with Double-Porosity Porous Aluminum Skeleton/Paraffin Phase Change Material.

Phase change materials (PCMs) are used to cool high-power-density electronic devices because of their high latent heat and chemical stability. However, their low thermal conductivity limits the application of PCMs. To solve this problem, a double-porosity porous aluminum skeleton/paraffin phase change materials (DPAS/PCM) was prepared via additive manufacturing and the water-bath method. The thermal performance of the DPAS/PCM heat sink (HS) was experimentally investigated to examine the effects of the positive- and reverse-gradient porosity structures of the DPAS/PCM. The results show that a positive-gradient porosity arrangement is more conducive to achieving a low-temperature cooling target for LED operation. In particular, the temperature control time for the positive gradient porosity structure increased by 4.6-13.7% compared with the reverse gradient porosity structure. Additionally, the thermal performances of uniform porous aluminum skeleton/paraffin (UAS) and DPAS/PCMs were investigated. The temperature control effect of the DPAS/PCM was better than that of the UAS/PCM HS at high critical temperatures. Compared with the UAS/PCM HS, the temperature control time of the DPAS/PCM HS is increased by 7.8-12.5%. The results of this work show that the prepared DPAS/PCM is a high-potential hybrid system for thermal management of high-power electronic devices.

A novel biogenic porous core/shell-based shape-stabilized phase change material for building energy saving

The application of phase change materials (PCMs) for thermal storage in construction can effectively reduce building energy consumption. However, high costs and vulnerability to leaks have hindered their application. The present study proposes two approaches for the synthesis of porous supporting matrices derived from rice husk, resulting in the formation of rice husk silica (RHS) and rice husk carbon (RHC). Then, n-octadecane and the porous materials were combined by vacuum impregnation, while the leakage resistance performance of the composite PCMs was enhanced by applying epoxy resin coating to create a shell-core structure. The results show that the n-octadecane/RHS and n-octadecane/RHC composite PCMs exhibit high latent heat potential of 106.5 J/g and 116.3 J/g, respectively. Both porous supporting structures provided the PCMs with robust structural stability and exceptional thermal conductivity. The thermal conductivity of the n-octadecane/RHS composite PCMs and n-octadecane/RHC composite PCMs reached 0.52 W/(m K) and 0.41 W/(m K), respectively. The thermal properties of the biogenic porous core/shell-based shape-stabilized PCMs were characterized by an analog T-history method, and the results demonstrated that the composite PCMs exhibited excellent and rapid heat storage and exothermic capabilities. After undergoing 300 complete heating and cooling cycles, the composite PCMs demonstrate exceptional thermal reliability and possess a high enthalpy capacity. Finally, the impact of the pore structure of RHS and RHC on the crystallization behavior of n-octadecane was discussed. Both composite PCMs can be regarded as environmentally friendly construction materials with promising thermal and acoustic properties.

Heat capacity study of fatty acids as phase change materials for thermal energy storage

Fatty acids are commonly used as phase change materials (PCMs) for thermal energy storage due to their high latent heat, non-toxicity, and biocompatibility. However, the thermodynamic properties of fatty acids have not been systematically studied, especially for their heat capacity data over a wide temperature range. This limitation greatly restricts their practical applications in designing and constructing fatty acids based PCMs and corresponding thermal management techniques. Herein, the heat capacities of a series of fatty acids (octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid) have been measured using a combined relaxation, adiabatic, and differential scanning calorimetry techniques over a temperature range from 1.9 K to 380 K. The corresponding thermodynamic functions and phase transition thermodynamic parameters have been calculated based on heat capacity data fitting. Additionally, the thermal stability and thermal conductivity of these fatty acids have also been determined using a thermogravimetric analysis instrument and a thermal constant analyzer, respectively. These obtained thermodynamic properties can provide crucial fundamental information for the study and application of fatty acid PCMs and related thermal energy storage techniques.

Application of phase change material on solar-greenhouse back wall and its effects on indoor thermal environment and cucumber production in winter

The configuration of the solar greenhouse building wall and the thermal properties of the building materials directly impact wall insulation, heat storage characteristics, and, consequently, the thermal environment within the greenhouse. To address the variations in wall heat storage during the design and construction of solar greenhouses, this study aims to integrate solar energy effectively with phase change heat storage technology. Utilizing Energy Plus, the study simulates and verifies the heat storage and release performance of phase change materials on the greenhouse's back wall. The research also explores the warming effect of these materials on cucumber growth. The findings reveal that the composite phase change greenhouse (PC) wall exhibits an average heat release of 60.47 W/m2, maintaining an average temperature of 21.09 °C. In comparison, the heat release from the back wall of the traditional greenhouse (CK) increases by 14.03 W/m2, resulting in a temperature rise of 1.91 °C. Additionally, the substantial heat released by the phase change wall raises the average ground temperature to 18.26 °C through heat conduction, exceeding CK by 3.07 °C. Despite this, the maximum temperature remains below 25 °C, creating an ideal growth temperature for cucumbers and fostering vigorous growth. Furthermore, cucumber quality indicators, such as soluble sugar and VC content, significantly improve, demonstrating a 28.5 % increase in the single fruit weight of cucumbers. In conclusion, the composite phase change greenhouse outperforms the traditional greenhouse in heat storage capacity. The heat storage wall effectively enhances the overall thermal environment, insulation, and heat storage performance, ultimately leading to increased cucumber yield and quality.

The cores regulation of paraffin-chitosan phase change microcapsules for constant temperature building

Phase change materials (PCMs) can store and release latent heat under the designed phased change temperature and have received substantial interest for energy conservation and thermal control purposes. The use of PCMs in the construction of constant temperature buildings can improve the comfortable environment and save more energy. However, the leakage of PCMs during phase change process limits the application of PCMs. In this paper, a series of PCMs microcapsules with controllable core numbers is synthesized with paraffin (37 ℃) as the core and cross-linked chitosan as the wall. The single-core phase-change microcapsules (S−PCM) and multicore phase-change microcapsules (M−PCM) were prepared by adjusting the preparation condition. The latent heat of S−PCM and M−PCM are 61.4 mJ mg−1 and 50.1 mJ mg−1, respectively. The S-PCM and M−PCM display good stability without paraffin leakage. In addition, the composite blocks of gypsum and S−PCM (GSCM) and M−PCM (GMCM) were prepared and the thermoregulatory effection was investigated, where the surface temperature of GSCM was 5–10 ℃ lower than that of pure gypsum block. PCMs may also have broad application space in electronics, cold chain, and other industries.

Synthesis of Form-stable Phase Change Materials for Application in Lunch Box to Keep the Food Warm

Introduction: The invention of a lunch box with phase-change materials incorporated to keep food warm throughout work hours is the subject of this paper. Since harmful chemicals render the food unfit for consumption when they come into contact with it, the choice of phase change material is essential. Method: Adopting a healthy lifestyle now includes carrying electronic lunch boxes and ordering takeaways. Nevertheless, utilizing the electric lunch box at work is a bother. Therefore, this study discusses a prototype of a lunch box that has been created and can keep food warm after it has been packed at home for 4-5 hours. The method of preparing the PCM FS65 is discussed and its stability over thermal cycling is analyzed. objective: To synthesize phase change material composite which does not go into liquid state in melting cycle. To understand the thermal stability of the phase change material composite To prove the efficacy of the composite in lunch box for keeping the food warm Result: The thermal resistance of the insulating materials and the quantity of PCM are the two design considerations for the lunch box that have been covered in this study. To explore these, a warm food criterion at a temperature of 45°C has been used. Conclusion: This research article has discussed the ideal PCM weight required for a 5-hour retention time as well as the ideal insulating material to make the least bulky lunch box design.

Experimental analysis of building envelope integrating phase change material and cool paint under a real environment in autumn

The application of phase change material (PCM) and cool paint (CP) to building envelope is one of the effective solutions to improve thermal comfort of passive buildings. Therefore, the thermal performance of buildings in Hefei, China in autumn is compared and analyzed by integrating PCM and CP into the building envelope. According to the comprehensive analysis of indoor thermal environment and the ability to maintain indoor thermal comfort, it is concluded that the combined application of PCM and CP is better than the application of PCM or CP alone. And the combination of PCM and CP laid on the south wall and roof respectively is the best. It is more suitable for commercial buildings, which can prolong indoor air temperature (Ti) in the thermal comfort zone for more than 10 h during the day. The combination of PCM and CP laid on the roof can prolong Ti in the thermal comfort zone for more than 8.05 h, which is more suitable for residential buildings. The purpose is to explore the best combination mode of residential and commercial buildings according to the characteristics of temperature change and building types (according to people's main use time) in the real environment.

Analysis of melting behavior of layered different phase change materials for a cylinder insert into a channel

Phase change materials (PCMs) have diverse fields of application due to higher thermal inertia. The present study explores the melting behavior in dual-layered different PCMs in a cylindrical lithium-ion battery module placed in a long channel under the hot air stream. The main cylinder is packed with paraffin wax and covered PCM is chosen as calcium chloridehexahydrate (CaCl2-6H2O). The material between two PCMs is considered highly conductive and impermeable. The involved mathematical equations in two-dimensional forms are numerically simulated the applying the finite volume technique. The primary important parameters of melting behavior are the difference in temperature and inlet air velocity. The analysis is carried out for the effective parameters such as the inlet air temperature (Thot = 100 °C and 120 °C) and air velocity (սair = 2.5 and 5.0 m/s). The results revealed that an increase in air velocity reduces the highest and average temperature of the PCM. The changes in melting time of PCMs decline with time. Higher inlet air temperature also causes fast melting of the PCMs over time. The analysis revealed that the application of PCMs is undue when there is no phase change process. The analysis also revealed that an increment in the inlet air velocity causes a decrease in the average temperature. For the same air inlet temperature (Thot) higher air velocity leads to a slower rate of the melting process Therefore, melting time is less by ∼ 30 % (for the inner layer) and 32 % (for the outer layer) with decreasing air velocity. The findings of this study will help the designer to improve the battery thermal management system by modulating the temperature.