Thermal Energy Storage Capacity Research Articles

Synthesis and characterization of wood-based phase change material with high photothermal conversion efficiency

Abstract Phase change materials attract tremendous interest for building energy conservation due to their auto-temperature regulation and thermal energy storage capacity. However, its practical application is hindered due to the leakage problem and poor photothermal conversion efficiency. To address these issues, a scalable wood-based phase change material was prepared by impregnating polyethylene glycol (PEG) into wood particles doped with Fe3O4 and subsequent a hot press in this study. PEG was encapsulated by wood particles through its abundant pore structure and leakage rate of prepared wood-based phase change material (FWPCM) was only 2.9%, which solved the leakage problem effectively. FWPCM presented high latent heat of 73 J g−1 and slowed down the temperature change obviously. Addition of Fe3O4 powder endowed FWPCM a high photothermal conversion efficiency and thermal conductivity (0.3545 W/(m*K) was increased by 125% compared to PW. So FWPCM had potential to be used as building engineering material for energy collecting, storage and conversion benefited by its great thermal performance, superior durability, simple preparing process and acceptable mechanical property.

Cellulose-based phase change membranes with reversible optical transmittance and lignin ester-enhancing photothermal conversion performance

Leakage issues and low photothermal conversion efficiencies have limited the application of organic solid–liquid phase-change materials. Herein, cellulose-based phase-change membranes (CPCM-FAS-LUEX) were prepared by physically blending three fatty alcohols (1-dodecanol, 1-tetradecanol, and 1-hexadecanol) with a cross-linked network composed of cellulose 10-undecenoyl ester (CUE), lignin 10-undecenoyl ester (LUE), and octadecyl acrylate (OA) with 2,2′-azobis(2-methylpropionitrile) as an initiator. In addition to being part of the network structure, LUE acted as a photothermal conversion enhancer. During phase change processes, the prepared membranes exhibited reversible optical transmittance, the response temperature of which could be adjusted (21–49 °C) by using different fatty alcohols. Differential scanning calorimetry revealed that the CPCM-FAS-LUEX membranes possessed good thermal energy storage capacities, with melting enthalpies up to 134.9 J/g. The introduction of LUE significantly improved the photothermal conversion performance, with an increase in efficiency from 42.06% to 88.66% at a light intensity of 230 mW/cm2. It is noteworthy that reversible optical transmittance and high photothermal conversion efficiency were achieved in the same materials. Hence, the synthesized CPCM-FAS-LUEX membranes have potential for use in thermal–response materials and solar–thermal storage and conversion systems.

Numerical simulation study of closed-loop geothermal system well pattern optimisation and production potential

Previous numerical simulation studies on U-shaped closed-loop geothermal systems (UCLGS) have been based on single horizontal well, but the reservoir temperature influence range of single well is limited and cannot effectively utilize deep geothermal resources. There are few studies on the well pattern design of UCLGS, especially concerning the shape, number, and arrangement of well. Therefore, we proposed a grid-shaped horizontal well heat exchange system of multi-layer and multi-branch to achieve optimal heat transfer and fluid circulation effect. The effects of the well layout location, injection-production ratio, number of grids, and well length on the heat extraction performance were investigated by numerical simulations after establishing a three-dimensional geothermal mining model. We explored the temperature response characteristics of the reservoir. Finally, the actual production characteristics and potential of the grid-shaped horizontal well heat extraction system were characterised using production indicators, such as production temperature, heat production rate, accumulated thermal energy, and generated energy. The results showed that the diagonal well layout is more effective for heat extraction. Multiple injection wells and one production well mode is the optimal design scheme under the conditions of this study. In addition, when using the diagonal well layout, the system’s heat extraction capacity is positively correlated with the number of grids. However, when using the horizontal well layout, it is no longer proportional to the number of grids once the injection rate exceeds 3 kg/s. Increasing the well length can improve heat production efficiency, but it is limited by the total thermal energy storage capacity of the reservoir. When a single-layer well layout cannot meet the heat extraction requirements, a multi-layer well layout can be used to enhance the heat extraction capacity and reduce the interference of the well network system with the reservoir. Therefore, this well design promotes the efficient development of deep geothermal resources.

Microencapsulated phase change material incorporated light transmitting gypsum composite for thermal energy saving in buildings

The increased energy consumption for specific applications, including heating, cooling, air conditioning and lighting of residential and commercial buildings accelerate the research efforts concentrated on developing thermal energy storage capacity of buildings materials in recent years. Likewise, the development of light-transmitting building elements is a novel energy-saving technique that enhances lighting efficiency in buildings. In light of these, the current study seeks to design an untried microencapsulated phase change material (MPCM) integrated glass fiber reinforced gypsum composite with sufficient light-transmitting properties and thermal energy storage capacity. In this research, a multi-scale investigation of light-transmitting gypsum composite was conducted experimentally with physical, mechanical, chemical, microstructural, thermal, light transmittance and solar thermoregulation tests. The gypsum composite is formed from α-gypsum, water, polymer admixture, alkali-resistant glass fiber (AR-GF), several concentrations of MPCM, and plastic optical grids to allow light to transmit through the board. Although higher fractions of MPCM yielded an apparent decrease in mechanical strength test results, 5 wt% introduction of MPCM to the reference matrix reduced the compressive and flexural strength of specimens by 1 and 8 %, respectively. The results verified a reduction trend in thermal conductivity of composites with MPCM loading. DSC investigations revealed that the melting temperature and the regarding latent heat storage capacity of gypsum composite with 15 wt% of MCPM are 17.76 °C and 19.2 J/g, respectively. Light-transmitting gypsum composites showed up to ~10 % light transmittance, that can greatly increase the efficiency of lighting in buildings. The produced gypsum composites with MPCM kept the test room cooler during the highest temperature, while it provided a warmer room during the nighttime for an extended time. The study's findings are applicable to increase thermal comfort by reducing the significant temperature variations in buildings and improving artificial lighting efficiency, encouraging the design of sustainable building applications.

Thermal properties of phase change materials ionic liquid/fatty acids for thermal energy storage applications

Researchers have developed advanced energy storage techniques in response to the depletion of energy resources and the escalation of environmental problems caused by increasing population and technological advancements. One of the most promising methods to overcome such issues is the latent heat thermal energy storage (TES) method, which employs phase change materials (PCMs). TES using PCMs are an important category of novel materials that significantly contribute to the efficient use and conservation of solar energy and wasted heat. This work presents a new family of PCMs based on ionic liquid (IL) tris(2-hydroxyethylammonium) formate and fatty acids for the first time that operate in the temperature range of 50–150 °C and offer a safe and inexpensive capacity. Good chemical and thermal stability, low flammability, and low volatility along with the potential to tune chemical and phase properties provide an inherent “green” property for ILs that is well suited to PCMs. Using PCM3, tris(2-hydroxyethylammonium) formate/stearic acid, we demonstrate effective latent heat 246 J·g−1. The results of differential scanning calorimetry analysis show that the PCM2 tris(2-hydroxyethylammonium) formate/palmitic acid has a higher heat capacity 8.194 J·g−1·K−1 at the melting point than the other two PCMs due to its small alkyl chain. Thermal stability analyses show the maximum stability (98 %) for PCM3. Additionally, based on the structure of these PCMs, this study explores the molecular basis for the high thermal energy storage capacity of these materials and highlights the significance of hydrogen bonds in PCM performance. Using simple, cost-effective materials, this method gets around the complexity and expense of composite PCMs. We present design recommendations for implementing our approach in the management of thermal energy storage applications.

An overview of phase change materials and their applications in construction industry: Review

In recent days the energy consumption is increasing day by day for various regular activities. Construction industry plays a vital role which consumes higher energy than other industry. The various strategies are followed by Engineers and alternate material are used in building construction to reduce energy consumption. The Phase Change Material (PCM) is considered as one of the alternate materials which is to maintain the comfort condition and moderate temperature inside the building. The PCM can accumulate and liberate the energy within controlled temperature. The PCM are available in the form of Organic, In-Organic and Eutectic forms. The applications of PCM are used with concrete, cement mortar and insulation roofs for thermal purpose. This paper reveals detailed review about latent heat storage, melting point, thermal energy storage capacity, mechanical and thermal properties and in PCM blended materials. Thermal properties and energy storage capacity of the PCM materials were analysed with and without PCM by the help of energy simulation software. The Eutectic compound of PCM will be the recent development in concrete and construction materials to reduce the temperature.

Experimental study on a channel-embedded sensible thermal energy storage unit with the heat storage body immersed in heat-conducting oil

ABSTRACT In order to study the feasibility of a liquid working medium working in a solid heat storage body, this paper experimentally studied a novel pilot-scale sensible thermal energy storage unit (STESU) with a channel-embedded solid thermal energy storage body (STESB). The material of the body with fluid channels is corundum castable, and the heat-conducting oil works as a heat-transfer medium. While working, the heat-conducting oil flows through the fluid channels of the solid thermal energy storage body, and the oil submerges the body for convection heat exchange in the unit. The charging experiments under different flow rates were carried out to evaluate the thermal performance of the heat storage unit, including temperature, power, and efficiency. The results indicate that the unit’s thermal energy storage capacity is about 1.054 × 106 kJ. When the flow rate increases from 2.0 kg · s−1 to 2.8 kg · s−1, the heat storage power increases from 71.90 kW to 90.58 kW, the total heat transfer area and heat transfer coefficient increases from 3.29 to 3.60 W/K, and the working efficiency of the charge-discharge cycle is 95.6%, which indicates that the thermal performance of the unit is better than that of heat storage unit which uses air as the heat transfer working medium.

Effect of enhancement in metal foam pore density on heat transfer of phase-change materials

To explore the effect of metal foam(MF)pore density on the melting and heat transfer of phase-change materials(PCMs), a semi-cylindrical visualization experimental setup was established to experimentally study copper MFs with different pore densities coupled with paraffin wax. The results showed that as pore density increases, the melting time of the composite PCMs decreases compared to that of pure paraffin wax by 11.5%, 16.2% and 18.1% for pore densities of 5, 20, and 30 PPI, respectively. Composite PCMs with a pore density of 30 PPI exhibited fastest melting and lowest maximum temperature difference during melting. Considering the relative thermal energy storage(TES) capacity and relative TES rate, composite PCMs with a pore density of 30 PPI exhibited optimal overall thermal storage performance. Furthermore, heat conduction was the primary means of thermal transmission during the melting of the bottom paraffin. However, the melting of the upper paraffin was nevertheless influenced by natural convection, Hence, as pore size decreased, the influence on the weakening of natural convection became more significant. The results of the study provide guidance for the optimal design of latent heat storage devices for semi-cylinders.

Shape-stable erythritol composite phase change materials with controlled latent heat release for spatiotemporally thermal energy utilization

Phase change materials (PCMs) have been extensively concerned recently as suitable medium for thermal energy storage due to their absorbing or releasing a large amount of latent heat in the phase change process. However, traditional PCMs usually crystallize spontaneously to release their latent heat in the cooling process, which greatly limits their practical application in thermal energy long-term storage and controllable release. Herein, we designed and synthesized a shape-stable erythritol (ERY)-based composite PCM with attractive performance of latent heat controlled storage and release using a facile aqueous fabrication route. In this composite, calcium ions cross-linked with sodium alginate is introduced to construct strong hydrogen bonding with ERY to increase the activation energy barrier for stabilizing supercooling, thus realizing long-term latent heat stored in supercooling state. The supercooled ERY composite can be maintained at room temperature for 50 days and subsequently controllably releases latent heat by thermal or mechanical trigger method. Meanwhile, the ERY composite exhibits excellent shape stability without any leakage over the phase change temperature. In addition, the crystallization enthalpy can reach 181.2 J/g, which can be maintained even after 80 thermal cycles, showing superior thermal energy storage capacity and repeatability. The crystallization kinetics study reveals that the crystallization mode of the ERY composite is three-dimensional growth spherical diffusion. This work provides an important strategy for the design and synthesis of shape-stable PCMs with controllable latent heat storage and release performance, which is of great prospect for the development of spatiotemporally thermal energy storage technology.

Optimization of UiO-66/CaCl2 composite material for thermal energy storage

Thermal energy storage technology can effectively solve the problems of mismatch between the supply and demand in solar thermal utilization. Injecting salt hydrates into porous matrices to develop composite materials could improve the thermal storage performance of pure salt hydrates. Recent studies have shown that UiO-66 could be a promising matrix of adsorption heat storage composite materials. In this paper, to optimize the UiO-66/CaCl2 composite material for thermal energy storage, a series of composite materials were prepared with injecting CaCl2 into UiO-66 of different crystal size and then characterized with various instruments. The results showed that the adsorption performance of the composites was determined by both the salt content and the crystal size of UiO-66. Among all the materials, it was found that U (100)-Ca30 had the best adsorption capacity, which was up to 1.80 g/g at 30 °C and 80% RH. The results of Kissinger equation fitting showed that the desorption activation energy of U (100)-Ca30 at low-temperature zone was lower than that of UiO-66. Moreover, the results showed that the thermal energy storage capacity of U (100)-Ca30 was up to 1416 J/g and it had also shown excellent stability with 16 times of cycling. All of the above results demonstrated that U (100)-Ca30 could be a potential candidate for adsorption thermal energy storage.

Provision of multiple services with controllable loads as multi-area thermal energy storage

Power systems are experiencing a decrease of synchronous generation along with increased penetration of inverter based renewable generation leading to reduced system inertia and a need for flexible resources. Non-generating resources such as thermostatically controlled loads (TCLs) are flexible due to their thermal energy storage capacity. When aggregated, TCLs can arbitrage energy prices and provide reserves to the power system. We approach the operational flexibility of the TCLs by modeling a risk-averse aggregator that controls decentralized TCLs and aims to maximize its own profit. The high number and low power rating of residential TCLs makes it difficult to model and assess their flexibility potential on national level. Thus, we make use of a high-level thermal energy storage model for aggregations of TCLs to quantify their flexibility potential. We present a method to aggregate temperature, TCL parameters, and building stock data into a thermal battery equivalent. We propose a multi-period multi-market multi-zonal two-stage chance constrained rolling horizon optimization problem formulation for the risk-averse day-ahead self-scheduling problem of a price-taker TCL aggregator bidding in energy and reserve markets under uncertainty and recast the problem as a linear program. We perform several case studies in the Swedish power system based on a survey of single- and two-family dwellings with electric heating and assess the flexibility potential. Additionally, a sensitivity analysis provides insights regarding market design and policy implications.

Unveiling the effect of molecular chain length on the thermal energy storage capacity and transition temperature of alkane-based phase change composites

Thermal energy storage systems based on phase-change materials (PCMs) have garnered significant attention, because they can overcome intermittency issues related to renewable energy sources. However, the energy storage capacity and phase-change temperature of phase-change composites largely depend on the PCM type and molecular weight, in addition to the supporting material type, and experimental studies on the thermal properties of PCMs with different molecular chain lengths are scarce. In this study, phase-change composites were prepared by the vacuum impregnation method using boron nitride (BN) as the support and n-alkanes of different chain lengths–dodecane (C12H26), and docosane (C22H46)–as the PCMs to study the effect of the alkane chain length on the thermal energy storage density and phase-change temperature. The BN@C22 composite exhibited greater latent heat storage capacity (125.11 kJ/kg) than the BN@C12 composite (70.84 kJ/kg), indicating the low confinement effect of the BN support on the long-chain n-alkane. In contrast, the BN functional groups and shorter-chain n-alkane had strong intermolecular interactions, which compromise the energy storage density for seepage resistance and shape stability. Both PCM composites exhibited good chemical compatibility between the two components, improved thermal durability, and insignificant leakage rate (up to 98.7% leakage resistance capability), while BN@C12 showed higher shape stability. The thermal performance of the as-prepared PCM composites, including their phase-transition temperature (range: −9.54 to + 43.53 °C), illustrates their potential for various thermal management applications, including indoor temperature-control systems. This study provides fundamental guidelines for tuning the working temperature range and improving the efficiency of thermal management systems.

Developing a solid–solid phase change heat storage asphalt pavement material and its application as functional filler for cooling asphalt pavement

Currently, functional pavement materials become a research hotpot for road researchers. This paper aims to develop a phase change heat storage asphalt pavement material and then design phase change heat storage asphalt mixtures with active cooling ability. The synthesized polyurethane-based solid–solid phase change material (PUSSPCM) with suitable phase change temperatures, desirable thermal energy storage capacity and excellent phase change cycling stability can meet the active cooling demand of asphalt pavement. There are also excellent leakage resistance, volume stability and chemical stability that enable withstanding the harsh condition of asphalt pavement. Therefore, the PUSSPCM can be considered as a promising phase change filler. Subsequently, the phase change heat storage asphalt mixtures are prepared by the equal volume replacements of limestone filler with PUSSPCM. The replacements can improve the high-temperature stability and low-temperature cracking resistance whereas weaken the water stability of an asphalt mixture. When the replacement amount is no more than 40 vol%, the phase change mixtures can satisfy the pavement performance requirements. The replacements increase the heat absorption capacity but decrease the heat transfer rate, which leads to decrease in the temperature rising rate of the asphalt mixture with more PUSSPCM.

Development of rigid polyurethane foam incorporating phase change material for a low‐temperature thermal energy storage application

AbstractPolyurethane (PU) foam is most commonly used in thermal insulation in cold storage applications but it lacks thermal energy storage characteristics. In the present work, a phase change material (PCM) n‐tetradecane is microencapsulated with poly(methyl methacrylate‐co‐methacrylic acid) using oil‐in‐water emulsion polymerization followed by incorporation into the PU foam formulation to fabricate composite foam. The purpose of the study was to combine thermal insulation along with thermal energy storage characteristics into PU foam. The phase change enthalpy of PU foam was improved from 22.43 to 55.46 J g−1 by changing the microcapsule loading fraction from 10% to 30%. The composite PU foam exhibits good thermal reliability even after 100 thermal cycling tests. The morphological observation confirms a decrease in cell size while increasing the microcapsule content. It is found that microcapsule addition has no effect on the thermal stability of PU foam. A prototype has been fabricated and tested, showing an enhancement in the thermal energy storage capacity of PU composite foam. This performance makes this PU‐PCM system feasible for cold energy storage applications. © 2022 Society of Industrial Chemistry.

Effect of carbon nanotube and microencapsulated phase change material utilization on the thermal energy storage performance in UV cured (photoinitiated) unsaturated polyester composites

The utilization of phase change materials in the synthesis of polyester is an economically viable approach for the production of polymer composites with remarkable thermal and mechanical characteristics, thereby facilitating thermal energy savings. This study manufactured a series of unsaturated polyester resin (UPR)/carbon nanotubes (CNT)/MPCM composites via mechanical mixing and ultrasonication processes and the produced composites were cured with ultraviolet (UV) curing technology. The unsaturated polyester resin was utilized as a support matrix, and to improve the thermal conductivity of MPCM-UPR composites, CNT were introduced into the matrix. This paper discusses the effect of CNT and MPCM on the mechanical, thermal, and thermal regulative performance of polyester composites. A 10 wt% incorporation of MPCM led to an almost 77 % and 15 % drop at Charpy impact strength and Shore D hardness values of reference UPR, respectively. Similarly, the introduction of substitution of 0.005 wt% of CNT reduced the impact strength of the specimen with 10 % MPCM by 31 %, while it increased the Shore D hardness by almost 5 %. Although the thermal conductivity of reference resin was reduced by 15 % with a 10 % addition of MPCM, CNT content increased the thermal conductivity values by almost 20 % regardless of MPCM concentration. The onset melting and freezing temperatures of MPCM were found to be 21.71 and 22.74 °C, respectively; while for the composites with and without CNT, this value ranged between 20.70 and 22.39 °C and 22.45–22.90 °C, respectively. Thermoregulation test results indicate that MPCM improved the thermal energy storage capacity of composites. The results of this research will be of great significance in order to gain a more comprehensive understanding of the thermal properties of polyesters with MPCM/CNT, thus allowing for the utilization of this material as a latent heat thermal energy storage system for energy conservation.

Experimental and numerical investigation of novel light weight concrete panels made with aerogel and phase change materials

Silica Aerogel (SAG) mortar is an ultra-lightweight cementitious composite. It has high heat-insulating properties, which helps to reduce building heating energy consumption. However, it may also increase overheating and peak cooling demand in buildings during summer due to low thermal mass to store thermal energy. Therefore, this study aimed to increase the thermal energy storage capacity of silica aerogel lightweight concrete panels (SAGP) by integrating Capric Acid (CA) Phase Change Materials (PCM). The CA was absorbed in Hydrophobic Expanded Perlite (HEP) porous materials to develop form stable capric acid hydrophobic expanded perlite (CAHEP) composite to prevent PCM leakage when melted. Various lightweight Heat Resistive and Storage Panels (HRSP) panels were developed by replacing sand with SAG and CAHEP composite at different volume fractions. Then, the thermophysical properties and thermal performance of those HRSPs were evaluated using appropriate standards and established methods. The results showed that the integration of 60% CAHEP in SAGP resulted in 43% and 56% higher thermal storage and inertia, respectively, compared to the reference SAGP without CAHEP. The developed HRSPs also have acceptable compressive strength and drying shrinkage for thermal insulating and plastering applications. Numerical simulation showed that the application of HRSPs on the interior surface of a typical Victorian house reduced annual energy use and greenhouse gas emissions by 9.14% and 24%, respectively, in air-conditioned buildings; and reduced summertime thermal discomfort hours by 42 h in a free running house during a heatwave period. Finally, the life cycle assessment revealed that HRSPs have lower environmental impacts than SAGPs. Thus, HRSPs can be a sustainable alternative to lightweight concrete panels.

Phase Change Materials for Life Science Applications

AbstractPhase change materials (PCMs) are a class of thermo‐responsive materials that can be utilized to trigger a phase transition which gives them thermal energy storage capacity. Any material with a high heat of fusion is referred to as a PCM that is able to provide cutting‐edge thermal storage. PCMs are commercially used in many applications like textile industry, coating, and cold storage typically for heat control. These intriguing substances have recently been rediscovered and employed in a broad range of life science applications, including biological, human body, biomedical, pharmaceutical, food, and agricultural applications. Benefiting from the changes in physicochemical properties during the phase transition makes PCMs also functional for barcoding, detection, and storage. Paraffin wax and polyethylene glycol are the most commonly studied PCMs due to their low toxicity, biocompatibility, high thermal stability, high latent enthalpy, relatively wide transition temperature range, and ease of chemical modification. Current challenges in employing PCMs for life science applications include biosafety and/or engineering difficulties. The focus of this review article is on the life science applications, evaluation, and safety aspects of PCMs. Herein, the advances and the potential of employing PCMs as a versatile platform for various types of life science applications are highlighted.

A multifunctional carbon-base phase change composite inspired by "fruit growth"

Inspired by fruit growth, we proposed a strategy for the preparation of multifunctional phase change materials (PCMs) based on carbon-based porous materials. The composite was fabricated by using polymerization reaction of resorcinol-formaldehyde resin (“pulp”) on the surface of three-dimensional skeleton of loofah sponge (“kernel”) to form porous foam via high temperature carbonization, followed by further vacuum adsorption of paraffin wax (“fruit juice”). With excellent electrical and thermal conductivity, light absorption performance as well as thermal energy storage capacity, the designed phase change composite (PCC) system demonstrated superior performance in temperature management, photo/electrical thermal conversion, multi-driver thermoelectric generation and electromagnetic interference (EMI) shielding. The graded porous structure of carbon foam allowed for high adsorption capacity (∼91%) of paraffin wax which was leak proof, ensuring high enthalpy of the fabricated PCC. Enhanced thermal/electrical conductivity allowed the as-prepared PCCs to provide multi-source driven thermal management performance and excellent EMI shielding (∼52 dB). In addition, the prepared multifunctional PCCs exhibited high photothermal conversion efficiency (∼84%) and enhanced efficiency for thermoelectric generation. In summary, this study provided a novel route for the preparation of multifunctional PCCs and provided broad application prospects in advanced thermal management, energy conversion EMI shielding for PCMs.

Unveiling sustainable nano-enabled phase change materials for high thermal stability and energy storage capacity

Thermal energy storage and conversion within phase change materials (PCMs) rely on the addition of supporting materials, such as nanomaterials, to improve leakage resistance and heat transfer properties. However, as the supporting fillers obtained from different sources and synthesis methods, the development of renewable and sustainable phase-change composites has received increasing attention in recent years. Here, we develop a phase change composite and adopt Ashby material selection alongside life-cycle assessment to compare and demonstrate the sustainability of different nano-enabled PCMs. The report considers both the environmental impact, economic feasibility and functional performance, including thermal conductivity and energy storage density. The assessment shows that biochar, a biomass derived carbon at low pyrolysis temperature, supporting paraffin composites shows an encapsulation efficiency of >50 %, high shape stability/leakage-resistance capability, suitable cumulative energy demand (100–1000 MJ/kg), and the lowest price (43.00 $/kg with one volume concentration) and price-performance ratio (0.48 $/kJ) In addition, the phase change composite exhibited high chemical compatibility with paraffin, high leakage-resistance (above the pristine phase change temperature at 50 °C) and lowest thermal conductivity (<0.4 W m−1 K−1) compared with other carbon-based phase change composites, such as graphene and carbon nanotubes supported paraffin, which is desirable and demanding for practical integration in insulation and building thermal energy management applications and can be used as an alternative carbon-negative sustainable phase change composite to reduce dependence on mineral-based construction materials.

Integration of lauric acid/zeolite/graphite as shape stabilized composite phase change material in gypsum for enhanced thermal energy storage in buildings

The effectiveness of Gypsum plaster loaded with Shape Stabilized Composite Phase Change Material (SSCPCM) in regulating indoor temperature of the building is experimentally investigated in this study. SSCPCM is composed of Gypsum/Lauric acid/Zeolite loaded with varying percentage of Graphite (0 wt%, 5 wt%, and 10 wt%). The SSCPCM-0, SSCPCM-5, and SSCPCM-10 were characterized for morphology, physical structure, chemical structure, thermal energy storage capabilities, thermal stability, and thermal conductivity using Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier Transformation Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry, Thermo Gravimetric Analysis (TGA), and thermal conductivity meter respectively. The results suggest that SSCPCM have excellent surface morphology and shows good chemical, thermal and physical stability. Thermal energy storage capacity of 81.08 J/g, 74.02 J/g, and 54.30 J/g at thermal conductivity of 0.242 W/mK, 0.427 W/mK, and 0.774 W/mk were shown by SSCPCM-0, SSCPCM-5, and SSCPCM-10 respectively. Additionally, SSCPCM-5 has shown superior thermal reliability by maintaining the thermo-physical characteristics after 1000 thermal cycles. These SSCPCMs were used to prepare GPCM, GPCM-5, and GPCM-10 composite gypsum plaster and five day real outdoor testing was conducted by applying them on indoor roof and south wall of cubicles. GPCM has effectively improves the indoor temperature profile in comparison with GPCM-5 and GPCM-10.