Hybrid Phase Change Materials Research Articles

Techniques for Enhancing Thermal Conductivity and Heat Transfer in Phase Change Materials in Hybrid Phase Change Material–Water Storage Tanks

In recent years, extensive research has been dedicated to enhancing energy efficiency and promoting environmental sustainability in heating and cooling systems. Among the promising solutions, phase change materials (PCM) technology stands out as a key area of exploration. This study focuses on improving the thermal performance of PCM–water hybrid tanks by investigating methods to enhance thermal conductivity and heat transfer. Through experimental testing using techniques such as copper matrices, steel twisted matrices, and copper spirals, this study demonstrates significant improvements in thermal conductivity, particularly with the use of copper matrices. The integration of a copper matrix placed in the PCM reservoir increased the heat transfer coefficient and thermal conductivity of the PCM, and thus, the total phase transformation time for solidification was reduced by 79.19% and for melting by 54.7%. Our experimental results demonstrate that the integration of a copper matrix can increase latent heat transfer from 55,677.6 J up to 125,274.6 J, marking a 125% enhancement over the experiment with pure PCM. Additionally, comparisons of the energy storage potentials for different PCMs underscore the benefits of integrating PCMs into hybrid storage tanks. These findings highlight the immense potential of PCM technology to increase energy storage efficiency in heating and cooling applications.

Influence of coupling air conditioner with hybrid PCMs on building interior conditions and consumed power: Experimental investigation

Air conditioning systems are vital for modern comfort but consume a substantial portion of global energy, contributing to environmental concerns and rising energy costs. PCMs can store and release energy during phase transitions, making them promise to reduce cooling loads. This study endeavors to empirically investigate the influence of integrating hybrid Phase Change Materials (PCMs), specifically PCMSP24E and PCMSP26E, with a real vapor compression refrigeration system. The primary focus is on assessing the consequential effects on the energy consumption of the refrigeration system and the interior environmental conditions within a building, including temperature and relative humidity. The energy usage of the split air conditioner wherein the outdoor unit is attached to PCMs tube heat exchanger for precooling the incoming air is investigated. Experiments reveal that PCM precooling effectively reduces the ambient air temperature entering the air conditioning condenser, leading to substantial energy savings. Increasing the PCM quantity enhances the system performance and refrigeration unit power saving. With 11 kg of PCMs, energy consumption by the air conditioning system decreases by 10.4 %, and indoor air temperature and relative humidity reduce by 0.5° and 5 %, respectively. Hence, PCM integration ensures a more consistent indoor temperature profile, enhancing occupant comfort and reducing temperature fluctuations.

Preparation and Properties of Graphene/Novel Degradable Plastics Hybrid Low Enthalpy of Phase Transition Materials

Graphene (GNs) were chosen to modify hybrid and novel degradable plastics PTLA/polymethyl methacrylate (PMMA). The low enthalpy of melting phase transformation (MEPT) materials (PTLA/PMMA)/GNs were prepared by adding the GNs at different mass fraction(1%, 2%, 3%, 4%) into PTLA/PMMA, and the properties of the hybrid phase change materials were characterized. The results indicated that the MEPT of PTLA/PMMA materials can be significantly reduced with the addition of GNs. The addition of 3% (mass) GNs made the MEPT of PTLA/PMMA material decreased by more than 50%. With the increase of GNs mass fraction, the MEPT hardly changed; Fourier transformed infrared (FT-IR) spectra showed that the interaction between GNs and PTLA/PMMA was physical; Scanning electron microscope (SEM) images showed that the components of GNs and PTLA/PMMA were mixed evenly without phase separation; The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) cycle performance tests showed that the decomposition temperature of the (PTLA/PMMA)/GNs material was up to 280 °C, and the properties could remain stable during the circulation process. The addition of GNs could effectively reduce the MEPT of the (PTLA/PMMA)/GNs material, increase the heat transfer efficiency, and have good thermal reliability.

Latest Advancements in Solar Photovoltaic-Thermoelectric Conversion Technologies: Thermal Energy Storage Using Phase Change Materials, Machine Learning, and 4E Analyses

In recent times, the significance of renewable energy generation has increased and photovoltaic-thermoelectric (PV-TE) technologies have emerged as a promising solution. However, the incorporation of these technologies still faces difficulties in energy storage and optimization. This review paper addresses these challenges by providing a comprehensive overview of the latest advancements in PV-TE technologies. The paper emphasizes the integration of phase change materials (PCMs) for thermal energy storage, also buttressing the use of encapsulated PCM for thermal storage and efficiency, and the use of hybrid PCM to enhance overall performance. Furthermore, reviews on the use of machine learning techniques for efficient optimization and the integration of thermoelectric modules into tandem perovskite silicon solar cells have been comprehensively analyzed. The advancements in photovoltaic-thermoelectric systems, as reviewed in this article, signify significant progress in attaining sustainable and effective energy production and storage. This review comprehensively addresses the 4Es, underlining their importance. It not only consolidates recent developments but also charts a path for future research in the field of PV-TE technologies, offering precise insights to guide upcoming studies and innovations.

Designing Next‐Generation Thermal Energy Storage Systems with Nanoparticle‐Based Hybrid Phase Change Materials: A Computational Analysis

The disparity between the supply and demand for thermal energy has encouraged scientists to develop effective thermal energy storage (TES) technologies. In this regard, hybrid nano‐enhanced phase‐change materials (HNePCMs) are integrated into a square enclosure for TES system analysis. Several HNePCMs are formulated with different highly conductive nanoparticles in varying proportions. For the numerical study, three HNePCMs, namely HNePCM‐1, HNePCM‐2, and HNePCM‐3, are employed to investigate melting characteristics and energy‐storage capacity analysis. The outcomes of the analysis are determined by examining several variables, such as mass fraction, enthalpy, and temperature, concerning the melting and heat‐transfer processes. In the results, it is indicated that HNePCM‐1_10% yields the best thermal performance as compared to the other HNePCM_8% and HNePCM_5% case studies. Furthermore, the melting time is shortened for HNePCM‐1_10%, HNePCM‐2_10%, and HNePCM‐3_10% by 20%, 10%, and 5%, respectively. The enthalpy of HNePCM‐1 exhibits greater enhancement compared to HNePCM‐2 and HNePCM‐3, respectively. The enhancement in energy‐storage capacity for HNePCM‐1_10%, HNePCM‐2_10%, and HNePCM‐3_10% is 18.69%, 16.66%, and 6.85% higher than that of the base material. Thus, HNePCMs are demonstrated to be more efficient materials and are emerging as potential materials to augment the performance of TES applications.

Thermal characteristics enhancement of Paraffin Wax Phase Change Material (PCM) for thermal storage applications

This study investigates the integration of graphene nanoplatelets and nano SiO2 into paraffin wax to enhance its thermal energy storage capabilities. Dispersing graphene nanoplatelets and nano SiO2 nanoparticles at weight percentages of 0.5 and 1.0 respectively, in paraffin wax yielded mono and hybrid phase change materials (HYB). Transmission electron microscopy, Field Emission Scanning Electron Microscopy and X-ray diffraction were used to determine the size and phases of secondary particles of graphene nanoplatelets and nano SiO2. Differential Scanning Calorimetry, Thermogravimetric Analysis and Thermal Conductivity Measurement were employed to investigate the impact of hybrid nanoparticles on thermo physical characteristics of paraffin wax. The weight fraction of nano particles distributed in the PCMs is directly related to the enhancement of thermal conductivity of hybrid PCM. The highest enhancement in thermal conductivity was observed when hybrid nanoparticles were present at a weight fraction of 1 %. The analysis shows that mixing graphene nanoplatelets and nano SiO2 with paraffin wax was uniform and the hybrid nanoparticles boosted its thermal conductivity by 38 %, 42 %, and 50 %, respectively. Experimental evidence indicate that the addition of nanoparticles can decrease the melting temperature and increase the solidification temperature of hybrid phase change materials (PCMs). When dispersed in large quantities, nanoparticles can alter properties like latent heat, specific heat, and viscosity. These promising findings suggest that graphene nanoplatelets and nano SiO2 can enhance paraffin wax's thermal properties for thermal storage application.

Implementation of Battery Thermal Management System for High-Performance Electromobility Application: A Hybrid Cold Plate and Phase Change Material Approach

Implementation of Battery Thermal Management System for High-Performance Electromobility Application: A Hybrid Cold Plate and Phase Change Material Approach

Numerical Investigation of the Thermal Performance of a Hybrid Phase Change Material and Forced Air Cooling System for a Three-Cell Lithium-Ion Battery Module

The thermal performance of a lithium-ion battery module comprising three cells contained within a casing was investigated at discharge rates of 3C and 5C with three different cooling strategies: forced air, phase-change material (PCM), and a hybrid system using a combination of forced air and the PCM. Three levels of fan speed (5000 rpm; 7000 rpm; and 9000 rpm) for cooling air flow were considered. A numerical simulation of heat transfer was performed using the ANSYS Fluent software. The electrochemical modelling of a battery was developed based on the NTGK approach, and the phase-change phenomenon was treated as an enthesis–porosity problem. The composite PCM, aluminum metal foam embedded in n-octadecane, had better heat dissipation performance than forced air convection. The PCM is significantly more effective at heat dissipation than forced air. Interestingly, when using a hybrid cooling system that combines forced air and a PCM, although it meets the operational requirements for Li-ion batteries in regard to maximum temperature and temperature uniformity at a 3C discharge rate, the airflow appears to have a negligible effect on thermal management and yields an indiscernible change in temperature. This can be attributed to a complex flow pattern that developed in a casing as a result of the suboptimal design of the inlet and outlet. Further studies will be required for the optimal positioning of the inlet and outlet, as well as the effectiveness of combining liquid cooling methods.

Numerical study of thermal management of pouch lithium-ion battery based on composite liquid-cooled phase change materials with honeycomb structure

To address the problem of temperature rise and temperature difference of lithium-ion pouch battery modules, this paper proposes a battery thermal management system (BTMS) with honeycomb structure of a new hybrid liquid and phase change material (PCM). The open-circuit voltage (OCV), internal resistance, open-circuit voltage temperature derivative, specific heat capacity and thermal conductivity of the battery are obtained from the experiments. Comparing the three BTMSs of air cooling, PCM cooling and hybrid cooling, it is found that the cell temperature exceeds the operating temperature using the air cooling scheme, while the hybrid cooling of PCM cooling and hybrid cooling scheme can effectively control the maximum temperature of the cell. A hybrid cooling (LPCM) scheme is used to study the liquid flow rate and inlet temperature as variables. When the coolant flow rate is 0.06 m/s and the inlet temperature is 36 °C, the maximum temperature and maximum temperature difference of the cell are 42.3 °C and 4.3 °C, respectively, and the LPCM has the best thermal management performance. The results show that the BTMS numerical model can provide a reference for the design of PCM schemes using hybrid liquid cooling.

Experimental investigation of influence of phase change materials in energy consumption of air-conditioning units and prediction performance evaluation of modified deep neural network model

In this study, the influence of hybrid phase change materials on the energy consumption of air-conditioning units installed to maintain a comfortable temperature inside the testing room was experimentally studied and numerically analyzed. The Paraffin, Halloysite and Ethylene glycol microcapsules were combined to form PHEg filler materials. These PHEg phase change materials were further mixed into a normal Portland cement mortar to prepare 5 different phase change material mortars. Based on the prepared motors, a pair of 1.22 m × 1.22 m × 0.2 m size test specimens were prepared to experiment. After testing the specimens with various outside temperatures, the energy consumed by an air-conditioning unit was reported. There was a 20–22% reduction in energy consumption recorded while testing with phase change material mortar specimens than normal cement mortar. Also, the results proved that the energy consumption of the air-conditioning unit could be reduced further by 10% when the outdoor temperature dropped to below 24 °C. In addition, the performances of prepared samples were predicted using a modified deep neural network model. The developed model accumulated 99.867% accuracy and a maximum of 0.1607 mean absolute error and 0.0172 root mean square error, better than several existing neural network models.

Design and Scalable Fabrication of Liquid Metal and Nano-Sheet Graphene Hybrid Phase Change Materials for Thermal Management.

Here, a paraffin/liquid metal (LM)/graphene hybrid thermal composite material with a high thermal-conductivity as well as high latent heat is developed. The paraffin is encapsulated in calcium alginate, which produces leakage-free phase change material (PCM) capsules. LM is filled amongthe gaps of PCM capsules to enhance overall heat conduction. Graphene nano-sheets coating attains efficient heat dissipation because of its high spectral emissivity (>91%) in the spectrum of the mid-infrared region. The developed material is verified to have strong compatibility and durable stability. The composite is utilized as a thermal buffer (TB) for central processing unit thermal management to demonstrate the synergy of these superior thermal properties. In certain cases, active cooling normally used could be replaced by the developed TB without any energy consumption for thermal management, demonstrating a completely passive cooling strategy. Compared to traditional heat sink active cooling, general energy savings of 10.4-26.3% could thus be achieved by the developed composite in wider operating conditions, proving itspotential for more efficient and sustainable data center cooling alongside thermal management of other ground-based electrical/electronic equipment.

Herbal myristic acid blended with expanded graphite for thermal regulation in construction materials

This study synthesized modified graphite (EG) through the ultrasonic dispersion method in brewed wine solution with myristic acid (MA) to create conduction of heat mechanism with a greater affinity for saturated fats. The resulting EG made a fatty acid hybrid phase change material (PCM) with excellent overall thermal behaviour. Fourier transform infrared spectroscopy, and X-ray diffraction showed that the synthesis involved physical adsorption rather than a chemical reaction. Differential scanning calorimetry studies showed that adding EG boosted the heat capacity of the hybrid PCM after 1000 heat storage and release cycles. Melting and freezing latent temperatures were 196.99 kJ/kg and 195.33 kJ/kg. Using thermogravimetric analysis (TGA), the thermal stability of MA/EG was evaluated. The SEM findings demonstrate effectively that EG uniformly surrounds the myristic acid's multi-pore structure and that the MA/EG is mostly silky. This revolutionary approach permits the development of hybrid phase-change composites with heat exchange abilities, high conductivity, and excellent thermal stability, which can be applied in a various energy storage technologies.

Reverse latent heat power generation properties of PCM/nanoparticles/metal foam at night

Nanoparticles and metal foam are doped with the phase change materials (PCMs) to improve the utilization efficiency of solar energy during the day. In order to investigate the latent heat power generation properties of this hybrid PCM at night, A photothermal conversion experimental platform was built in this paper, the effects of metal foam pore density (PPI=0, 5, 10, 15) and nanoparticle concentrations (ω = 0%, 0.5%, 0.8%, 1.0%) on the reverse temperature difference properties were investigated. Results indicates that PPI= 15 metal foam and ω = 1.0% nanoparticles can reduce the internal temperature of hybrid PCM by 35.92% and 20.93% respectively compared with pure paraffin. PPI= 15, 10, and 5 metal foam decreases the temperature difference, voltage, and power generation at most by 74.57%, 71.02%, and 74.54% compared with PPI= 0. Compared with ω = 0% nanoparticles, the temperature drop rates of ω = 1.0%, 0.8%, and 0.5% nanoparticles increase at most by 103.0%, 79.69% and 39.84% respectively. To a certain extent nanoparticles and metal foam are not conducive to reverse latent heat power generation although they are beneficial to photothermal performance. This research has reference and guiding significance for reverse latent heat power generation properties of PCMs doped with nanoparticles and metal foam at night.

Multi-objective optimization of integrated lithium-ion battery thermal management system

Battery thermal management system (BTMS) based on phase change materials (PCM) are demonstrating great performance in the field of high heat flux heat dissipation. However, traditional hybrid PCM modules focus too much on their thermal performance and ignore the weight issue, which greatly reduces their wide application. In this paper, a BTMS integrated air cooling channels, fins and PCM is proposed to improve the thermal performance of the battery. The maximum temperature (Tmax), temperature difference (ΔT) and weight (W) of BTMS are used as indicators for the evaluation of the battery performance. The balance between temperature uniformity and lightness of the lithium-ion battery pack is also analyzed according to the entropy weight-TOPSIS method. The results demonstrate that while the thermal performance of the battery pack is enhanced with PCM thickness (d) increases from 5 mm to 20 mm, the weight of the system increases significantly by 146.7 % as d increases. Besides, as fin height (l) increased from 5 mm to 65 mm, the liquid fraction increases by 20.4 %. According to the entropy weighting method analysis, the index weights of Tmax, ΔT and W are 28.37 %, 26.64 % and 44.99 %, respectively. Furthermore, after TOPSIS algorithm search, d = 7.5 mm and l = 65 mm are the best structural parameters for BTMS, and the corresponding Tmax, ΔT and W of BTMS are 319.29 K, 0.0135 K and 5.13 kg, respectively.

Multi-objective optimization of various type finned heat sink with phase change materials (PCM)

The paper focuses on optimizing hybrid PCM filled heat sinks with a multi-objective approach. In the current study, the fins are oriented both horizontally at the sidewalls and vertically at the bottom side in the enclosure. Two heat sinks with different types of fin shapes are introduced in the enclosure. A rectangular shape finned heat sink, and a tapered shape finned heat sink is incorporated in both sidewalls and bottom walls. The study’s main goal is to optimize the PCM-based heat sink to prolong the charging cycle (melting) and shorten the discharging cycle (solidification). The PCM used in the study is n-eicosane, and the material for the heat sink is aluminum. A heat flux with constant supply of 2000 W/m2 is provided at the enclosure bottom, and the remaining walls are insulated. A 2-D numerical simulation is done using the commercial software ANSYS Fluent. The multi-objective optimization is carried out using the technique for order preference by similarity to ideal solution (TOPSIS) optimization technique. For a constant PCM volume for both the cases, fin spacing, fin positioning, and fin heights are varied. The output results determined the optimum configuration for the stretched melting period and minimized solidification period.

Energy performance of buildings with composite phase-change material wallboards in different climatic zones of China

The incorporation of phase-change material (PCM) into construction materials has been proposed to indirectly accomplish indoor thermal comfort and energy saving. To adapt to seasonal changes (e.g., hot summer and cold winter), a novel type of hybrid PCM-containing wallboard (including three different PCMs) was proposed with a wide phase-change temperature range and that can work in various climates. In this study, a small building equipped with a hybrid PCM wallboard was established to evaluate energy-saving performance using EnergyPlus. To compare different hybrid PCM wallboards, four building models were considered, including Mode 1, Mode 2, Mode 3, and gypsum wallboard (BASE). The building performance in terms of heating and cooling energy consumption over one year was investigated at seven locations in China to represent different climate zones. The results show that less heating and cooling energy was required for Mode 2 than for the other models. Further investigation of the Mode 2 PCM wallboard revealed that the location of the PCM layer also influenced the energy savings. The total energy requirements for Mode 2 were lower than those for BASE by 2.15%, 4.33 %, 1.77 %, 5.56 %, 7.65 %, 5.84 %, and 0.2% for Shanghai, Beijing, Kunming, Lanzhou, Xining, Harbin, and Hong Kong, respectively. We conclude that the hybrid PCM wallboard can effectively reduce the heat gain through the building envelope throughout the year, presenting a considerable advantage of using it in buildings located in Shanghai, which experiences a hot summer and cold winter.

A mini review on paraffin‐graphene and related hybrid phase change materials for building energy applications

AbstractThe thermal energy management in building is gaining the significant attention in the present energy scenario to manage the temperature. Graphene‐related additives are known for their exceptional properties viz. excellent binding and high intrinsic thermal conductivity. The hybrid phase change materials (PCMs) with graphene additives have been applied to enhance the thermal conductivity. Graphene‐related materials are drastically used to improve the properties of PCMs. Incorporating graphene‐related fillers increase the thermal conductivity and preserve the latent heat storage ability of hydrocarbon‐based PCMs. Also, graphene‐related fillers can prevent the leaching properties of the PCMs. These composites can ease concerns regarding energy demand to some level by reversibly storing an incredible quantity of renewable as well as sustainable thermal energy helping to keep up thermal comfort and this has motivated authors to write present mini review. In this review, authors have described PCMs, preparation methods, graphene, graphene oxide, and their composite related PCMs, nanographene added PCMs and their applications in building envelopes utilizing graphene and relative additives.

Transmission/reflection/absorption individually control multifunctional metasurfaces

We propose a metasurface based on hybrid phase change materials GeTe and vanadium dioxide (VO2), which can manipulate the transmission /reflection /absorption of terahertz waves independently. By changing the external temperature from 25°C to 160°C, the function of this structure can be dramatically changed. When VO2 is in a dielectric state (i.e. 25°C), the designed structure behaves as a transmission-mode terahertz vortex beams manipulator. When VO2 is in a dielectric state (i.e. 68°C), the proposed structure serves as a reflection-mode terahertz vortex beams controller. When GeTe is in crystalline state (i.e. 160°C), the designed structure becomes as a terahertz perfect absorber at a frequency of 1.98THz within the incident angle of 30°. The proposed structure provides a new method toward the use of multifunctional terahertz devices for their potential in applications including terahertz wireless communication and detection.

Vertical orientation graphene/MXene hybrid phase change materials with anisotropic properties, high enthalpy, and photothermal conversion

Vertical orientation graphene/MXene hybrid phase change materials with anisotropic properties, high enthalpy, and photothermal conversion

Performance analysis of a novel hydrogen production system incorporated with hybrid solar collector and phase change material

In this technical article, a novel experimental setup is designed and proposed to produce a hydrogen by using solar energy. This system comprises a hybrid or photovoltaic Thermal (PVT) solar collector, Hoffman's voltameter, heat exchanger unit and Phase Change Material (PCM). The effect of PCM and mass flow rate of water on the hybrid solar collector efficiency and hydrogen yield rate is studied. This experimental results clearly showed that by adding the thermal collector with water, decreases PV module temperature by 20.5% compared with conventional PV module. Based on the measured values, at 12.00 and 0.011 kg/s mass flow rate, about 33.8% of thermal efficiency is obtained for water based hybrid solar collector. Similarly, by adding Paraffin PCM to the water based thermal collector, the maximum electrical efficiency of 9.1% is achieved. From this study, the average value of 17.12% and 18.61% hydrogen yield rate is attained for PVT/water and PVT/water with PCM systems respectively.