Phase Change Material Layer Research Articles

Enhancing thermal performance of phase change materials in building envelopes

AbstractPhase change material in conjunction with a passive latent heat thermal energy storage approach is a potentially effective way to solve the growing concerns about building energy usage. This research examines the thermal performance of building envelopes in Miskolc, Hungary. The factors impacting the thermal performance of phase change material integrated into the building envelope were assessed. The findings indicate that the enthalpy and melting temperature of the phase change material significantly impact the effectiveness of phase change material-based walls. It was determined the optimal location of the phase change material layer is possible. This determination is intricately related to the thermal properties of the phase change material and the prevailing environmental conditions.

A 3D Model of a Photovoltaic Thermal Panel with the Heat Transfer Fluid Tube Embedded in a Layer of Phase Change Material and Metal Foam

A 3D Model of a Photovoltaic Thermal Panel with the Heat Transfer Fluid Tube Embedded in a Layer of Phase Change Material and Metal Foam

Incorporating PCMs and thermal insulation into building walls and their competition in building energy consumption reduction

To diminish the 30 % share of buildings in final energy consumption, in this study, phase change material (PCM) and insulation are incorporated into the walls of the building. The primary goal is to determine whether insulation or PCM is more effective in reducing heat exchange through walls. Defining the parameters of the indoor setpoint (7 cases), the type of material (9 cases of PCM and one thermal insulation), the thickness of PCM or insulation (2 cases), and their location (3 cases: L1, L2, and L3), energy consumption (output parameter) was investigated in 420 cases. Because the geographic location of the building has a significant effect on energy consumption, in four different climate regions (ASHRAE index: 3B, 2B, 4B, and 4B), the competition between PCM and insulation in reducing energy consumption was investigated running 1680 cases. In the first climate zone, a layer of PCMs (3 cm thickness) with a melting range of 22–25 °C must installed at the L2 location to achieve the 61.8 % reduction in annual energy demand. If the thickness reaches 6 cm, the optimal material (PCM) should be installed at L3. If the indoor temperature is set higher than 27 °C, insulation should be installed instead of PCM. In the second and third zones, in all cases, it is better to install insulation than PCM. In the fourth zone, at a thickness of 3 cm, PCM can compete with insulation, but at a thickness of 6 cm, insulation is almost a better option. Numerical results affirm that in 71.4 % of cases, thermal insulation is superior to PCM. Genarally it is not recommended to install insulation/PCM in layers close to the building interior.

Numerical Analysis of a Two-Layer PCM Based Battery Thermal Management System for Different Material Properties

The design and numerical analysis of the two-layer PCM (Phase Change Material)-based thermal management system for a 18650-type lithium-ion battery have been performed. In relation to simulation, the coefficient of thermal conductivity and melting temperature of the first layer of PCMs are varied. Other parameters are made identical to that of the next layer's parameters in order that the generation of two different layers of PCMs can be attained: PCM-1 and PCM-2. To obtain a more realistic approach in the numerical analysis, the battery thermal model was created in the COMSOL-MATLAB interface using the experimental internal resistance data obtained for 18650 type Li-ion batteries in the literature. While a cheaper and more accessible material with a thermal conductivity of 0.2 W/mK and a melting point of 50 °C was used in the PCM-2 layer, the thermal conductivity was changed to 0.2; 1 and 5 W/mK in the PCM-1 layer; and the melting point was changed to 30, 40 and 50 °C. In this way, for PCM layers with different thickness (tpcm), the system was optimized at two different discharge rates, 5C and 7C. As a result of the numerical analysis, it was determined that the optimum tpcm, kpcm,1 and Tm values for the 5C discharge rate were 2 mm, 0.2 W/mK and 40 °C, respectively; and the optimum tpcm, kpcm,1 and Tm values for the 7C discharge rate were 4 mm, 5 W/mK and 40 °C, respectively.

Development of PCM tile for residential buildings in hot and dry climate: design and optimization

In recent years, the building sector has become more conscious of sustainability, and the use of phase change materials (PCMs) in concrete has gained more attraction. Integration of PCM with building facades is a successful method to reduce energy consumption and improve human comfort. However, no single PCM can work in an all-weather scenario. Hence, in this research work, an attempt is made to select a suitable PCM for Chennai city, India, and this methodology can be employed at any geographical location. The PCM tile is designed by including certain features to increase the thermal conductivity of the PCM zone. The optimum design of the PCM tile is achieved through multi-objective optimization techniques. L27 orthogonal array is employed, and all the tests were conducted through validated numerical simulation. Redesigned PCM tile includes a PCM layer of 2 cm thickness with a 10% mix of copper nanoparticles covered by plaster. Redesigned PCM tile reduces the peak indoor temperature by 6.62℃ compared with conventional roof systems.

Numerical study on air-cooled battery thermal management system considering the sheer altitude effect

Due to energy shortage and environmental pollution, vehicles and aircraft powered by Li-ion batteries have now received widespread attention. Among various types of battery thermal management systems (BTMSs), the air-cooled BTMS is still the preferred choice due to its affordability, longevity, and simplicity. To ensure the reliable operation of electric vehicles and aircraft at different altitudes, it is extremely meaningful and significant to study the thermal behavior of batteries at different altitudes. Therefore, for the investigation of altitude impact, this paper firstly proposes an indirect decoupling method to address the limitations of using ambient temperature as a single variable. Based on this, several different configurations of air-cooled BTMS have been investigated through numerical simulation. Then, for the tapering-type BTMS with the best thermal performance, the battery behavior at different altitudes is investigated and the influence law of sheer altitude factor is summarized. Subsequently, to address the thermal performance issues at higher altitudes, this research proposes three optimization measures, which include increasing inlet velocity, decreasing inlet temperature, and incorporating phase change material (PCM) layers, respectively. Ultimately, the entropy weight-TOPSIS method is adopted to seek the optimal measure at different parameters. The results indicate that as altitude increases from the standard altitude to 4000 m, the maximum temperature rises significantly, exceeding the permissible temperature range of Li-ion batteries. Besides, in order to effectively confine the maximum temperature within the permissible temperature range at an altitude of 4000 m, the inlet velocity should be increased by at least 2 m/s or the inlet temperature should be reduced by at least 3 °C. Among all optimized solutions, the solution with the addition of 0.4 mm PCM layers is the best based on the comprehensive evaluation of multiple indicators.

Experimental and Numerical Investigation for Optimization of a Hybrid Battery Thermal Management System based on PCM and Air Convection

Abstract This work presents the design and optimization of a phase change material (PCM) based hybrid battery thermal management system (HBTMS). In the first stage, experiments are performed to measure the battery cell temperatures under various charge rates with and without the usage of PCM. Thereafter, a numerical model is developed to conduct a parametric study on the effect of thickness of PCM layer around the battery cell. The maximum cell temperature (36.35°) and thermal nonuniformity are within the safe range for the PCM thicknesses of 6 to 12 mm. In the second stage, a parametric study is conducted in the 6S1P battery module to optimize the spacing between the cells at constant inlet velocity. The maximum temperature is within the optimal range when the cell spacing is 10 mm. At the constant cell spacing of 10 mm, increase in inlet velocities from 0.25 m/s to 2.5 m/s gradually improves the thermal non-uniformity. The maximum temperature and thermal non-uniformity for 6S1P battery module is found to be 42.07° and 1.17° respectively. In the third stage, 6S1P battery module is optimized for PCM thickness, cell spacing and inlet air velocity. It is found that effective thermal management is possible with PCM based HBTMS at low airflow rate of up to 1.5 m/s. The optimized PCM based HBTMS shows 46.59% and 40% reductions in PCM mass and air flow rate respectively.

Analysis and performance prediction of a building integrated photovoltaic thermal system with and without phase change material

Increasing energy demand in buildings in the last decade has led to more efficient usage of renewable energy. Building integrated photovoltaic/thermal systems is one of the effective ways of reducing energy consumption in buildings by providing heating, cooling, ventilation, hot water, and air. The enhancement of photovoltaic cell temperature reduces the electrical efficiency of photovoltaic panel systems. In this regard, the effects of cooling with air and phase change material layer are investigated in this study. The simulation of BIPV/T, PV, and heat pump was done in TRNSYS. As the main novelty of recent simulation, for the calculations of phase change material layer, MATLAB coupled with the TRNSYS, and Python software was used for the prediction process under the weather conditions of Sharurah, Saudi Arabia for 2022. Also, the performance of a building integrated photovoltaic/thermal system with a phase change material layer is predicted for 2024 and 2025 by the Random Forest machine learning method. The R squared, Root Mean Squared Error, and Mean Absolute Error are utilized for checking the accuracy of the model. Also, for more certainty, a validation was done on the simulated results of TRNSYS and the results showed high conformity of data. The simulated data for the first six months of 2022 showed that the maximum cooling effect happened in June with 25.47 °C and a 37.87 % reduction in photovoltaic cell temperature. Also, the best electrical efficiency improvement was 1.26 % while the thermal efficiency ranged from 29.65 % to 59.40 %, respectively. The predicted data was confirmed by R2, RMSE, and MAE equal to 96.64 %, 0.06 and 0.04. According to the simulation and predictions done, the annual electrical production of the building is achieved. The results indicate that, for the simulated system, about 29.7 %, 29.8 %, and 29.6 % of total energy utilization could be supplied by BIPV/T cooled with phase change material in 2022, 2024, and 2025, respectively.

Simulation and design of a solar chimney integrated with phase change material layer for building ventilation

The development of modern life requires new energy sources, and one of this energy is renewable solar energy uses in solar chimney for natural ventilation, but at the present time it is not greatly invested, taking into account the weather conditions of the region and the physical characteristics of solar radiation and air in the area in which the study will be conducted. The current study was carried out in Basrah city- Iraq, at longitude 47.749° and latitude 30.568°, where the solar chimney was facing south. The investigation was conducted using both theoretical and experimental studied. In the theoretical study, the solar chimney with the room in the presence and absence of PCM was simulated numerically using the finite volume method using the soft package ANSYS-Fluent/2021/R2. The effect of different tilt angles (α = 30°, 45°, and 60°), solar chimney air gap (gab = 10 cm, 15 cm, and 20 cm), and PCM basin thickness (tPCM = 3 cm, 4 cm, and 5 cm) were investigated. The results were presented in the form of contours of the distribution of streamlines, velocity, temperature, and liquid fraction of the solar chimney with the room, rate of temperature of the absorber plate with time and the rate of temperature of the PCM (TPCM) with time, rate of air change per hour (ACH). As for the experimental side, the device was built, and the intensity of solar radiation was studied for several days on 30 Sep. and 15 Oct. 2023, the temperature distribution rate of the absorbent plate over time, the PCM temperature rate, and the air change per hour (ACH). The theoretical results were compared with the experimental results, where there was good agreement, and the theoretical comparison was also made with several researchers. Significant results showed that the optimal ratio of the air gap width of the solar chimney is 15 cm, the inclination angle of the solar chimney α = 30°, and the thickness of the PCM basin (tPCM = 4 cm) to obtain the maximum ventilation rate. The thickness of the PCM basin = 4 cm gives the largest liquid fraction along time and maximum average temperature of the absorber plate. On the experimental, it was found that PCM convert into the liquid phase after its melting point, which is 340 K, after 12 noon, and the highest value of ACH reached 37 on September 30/2023 at midday.

The Use of PCMs and PV Solar Panels in Higher Education Buildings towards Energy Savings and Decarbonization: A Case Study

Buildings are one the largest energy-consuming sectors in the world, and it is crucial to find solutions to reduce their energy consumption. One way to evaluate these solutions is using building simulation software, which provides a comprehensive perspective. In this article, using DesignBuilder software (v 6.1), the effect of using phase-change materials (PCMs) on the external walls and ceiling of the Department of Mechanical Engineering of Shahid Beheshti University (Tehran, Iran) has been investigated. The methodology involves the use of a layer of PCMs for three locations: (1) on the walls; (2) on the ceiling; and (3) on both the walls and ceiling, with/without PV panels, which leads to seven scenarios (alongside the reference one). The result shows that using PCMs has a greater impact on the heating load than the cooling one and is more effective on ceilings than walls. For the simultaneous use of PCMs in the ceilings and walls, the heating and cooling loads, in comparison with the initial condition of the building, are reduced by 24%, and 12%, respectively. When using solar panels, the heating load increases by 12.6%, and the cooling load decreases by 8.6%, whereas the total energy consumption of the building is fairly constant when using both PV panels and PCMs. In these last conditions, the primary evaluated values shifted significantly. Notably, CO2 emissions saw a nearly 50% reduction, making the simultaneous use of PV panels and PCMs on both walls and ceilings the best performance option.

Controlled bioorthogonal activation of Bromodomain-containing protein 4 degrader by co-delivery of PROTAC and Pd-catalyst for tumor-specific therapy

The precise and safe treatment of bioorthogonal prodrug system is hindered by separate administration of prodrug and its activator, which often results in poor therapeutic effects and severe side effects. To address above issues, we herein construct a single bioorthogonal-activated co-delivery system for simultaneous PROTAC prodrug (proPROTAC) delivery and controlled, site-specific activation for tumor-specific treatment. In this co-delivery system (termed AuPLs), prodrug (proPROTAC) and water-soluble Pd-catalyst are first encapsulated by gold nanocubes (AuNCs), which are further coated with a layer of phase-change material (lauric acid/stearic acid, LA/SA). Below 39 °C, the solid state of LA/SA prevents the activation of Pd-mediated bioorthogonal reaction due to the solidification of Pd-catalyst and proPROTAC. Nevertheless, once over 42 °C, the phase change of LA/SA into liquid state, enabled by the photothermal effect of AuNCs, triggers the simultaneous release of proPROTAC and Pd-catalyst and initiates the in situ bioorthogonal reaction for proPROTAC activation. In the tumor-bearing mouse models, the systemic administration of AuPLs results in the accumulation in tumor region, where the photothermal effect activates and controls the tumor-specific bioorthogonal reaction to degrade BRD4 protein, leading to anti-tumor effects with minimized side effects. Overall, the co-delivery proPROTAC and Pd-catalyst and controlled activation by photothermal effects provide a precise way for biorthogonal-based anticancer prodrugs.

Experimental study of dual nano-network, high-temperature resistant aerogel material as an integration of thermal management functions

Thermal management system is highly desirable to guarantee the performance and thermal safety of lithium-ion batteries, but it reduces the energy density of battery modules and even is unable to provide highly effective protection. Here, a thermal management function integrated material is presented based on high-temperature resistant aerogel and phase change material and is applied at both charge–discharge process and thermal runaway condition. In this sandwich structure Paraffin@SiC nanowire/Aerogel sheet (denoted as PA@SAS) system, SiC nanowires endow the middle aerogel sheet (SAS) a dual nano-network structure. The enhanced mechanical properties of SAS were studied by compressive tests and dynamic mechanical analysis. Besides, the thermal conductivity of SAS at 600 °C is only 0.042 W/(m K). The surface phase change material layers facilitate temperature uniformity of batteries (surface temperature difference less than 1.82 °C) through latent heat. Moreover, a large-format battery module with four 58 Ah LiNi0.5Co0.2Mn0.3O2 LIBs was assembled. PA@SAS successfully prevents thermal runaway propagation, yielding a temperature gap of 602 °C through the 2 mm-thick cross section. PA@SAS also exhibits excellent performance in other safety issues such as temperature rise rate, flame heat flux, etc. The lightweight property and effective insulation performance achieves significant safety enhancement with mass and volume energy density reduction of only 0.79% and 5.4%, respectively. The originality of the present research stems from the micro and macro structure design of the proposed thermal management material and the combination of intrinsic advantages of every component. This work provides a reliable design of achieving the integration of thermal management functions into an aerogel composite and improves the thermal safety of lithium-ion batteries.

Solution-derived Ge–Sb–Se–Te phase-change chalcogenide films

Ge–Sb–Se–Te chalcogenides, namely Se-substituted Ge–Sb–Te, have been developed as an alternative optical phase change material (PCM) with a high figure-of-merit. A need for the integration of such new PCMs onto a variety of photonic platforms has necessitated the development of fabrication processes compatible with diverse material compositions as well as substrates of varying material types, shapes, and sizes. This study explores the application of chemical solution deposition as a method capable of creating conformally coated layers and delves into the resulting modifications in the structural and optical properties of Ge–Sb–Se–Te PCMs. Specifically, we detail the solution-based deposition of Ge–Sb–Se–Te layers and present a comparative analysis with those deposited via thermal evaporation. We also discuss our ongoing endeavor to improve available choice of processing-material combinations and how to realize solution-derived high figure-of-merit optical PCM layers, which will enable a new era for the development of reconfigurable photonic devices.

Experimental study of a novel Radiative cooling-Dual phase change material roof under hot summer and warm winter climate

In hot summer and warm winter climates, phase change materials (PCMs), with their ability to absorb and store thermal energy, can effectively reduce indoor temperature fluctuations and lower cooling loads when applied to roofs. Therefore, this study proposes a novel Radiative cooling-Dual phase change material (RC-DPCM) roof and conducts experimental research on its regulation of indoor and outdoor thermal environments. This energy-efficient roof integrates radiative sky cooling with PCM latent heat storage technologies within a compact building envelope. The innovative dual-PCM configuration can store heat from both indoor sources and outdoor solar radiation during the day through integrated PCM layers. At night, radiative cooling materials emit heat to the deep universe, helping the PCM layers complete solidification. The thermal performance of the RC-DPCM roof was tested in hot summer and warm winter climates compared to other roof designs: a single layer of aluminum (AL) roof, the Aluminum-Thermal insulation (AL-TH) roof, the Radiative cooling (RC) roof, the Radiative cooling-Outside phase change materials (RC-OPCM) roof, and the Radiative cooling-Inside phase change materials (RC-IPCM) roof. Results showed that the RC-DPCM roof significantly improved indoor thermal comfort and efficiency. Compared with the AL roof, the RC-DPCM roof reduced the average indoor temperature by 1.13 °C (or 2.49 °C during working hours) and continuously dissipated heat from the indoor environment to the ambient environment, reducing the cooling load. Additionally, the RC-DPCM roof achieved a 172.9 % average cooling load reduction during working hours, outperforming other roofs, thus demonstrating its potential as an innovative solution for sustainable and energy-efficient buildings. The RC-DPCM roof effectively reduced peak indoor temperatures and cooling load, demonstrating its potential as an innovative solution for sustainable and energy-efficient buildings.

Enhancing energy efficiency of PCM wall in winter with novel PCM-DLCB coupling design

In order to enhance the thermal performance of the phase change material (PCM) wall during winter, a novel PCM and double-layer capillary bundles (PCM-DLCB) coupling wall is proposed. The PCM-DLCB wall utilizes the capillary bundle near the outer surface to capture solar energy during sunny winter days. The heat is then transferred to the capillary bundle near the inner surface through a circulating pump, promoting the melting of the PCM. Optimization and long-term operation comparison research were conducted using numerical simulation to investigate the potential of the PCM-DLCB wall to improve energy efficiency during winter. Five structural parameters, including the type of PCM, the position of the capillary bundle, the position and thickness of the PCM layer, the spacing of the capillary bundles, and the flow velocity in the capillary bundle, were selected as variables for structural and operation optimization. The optimization target was the accumulated heat gain from the inner surface of the wall. The research results indicate that: (1) The most suitable PCM is RT-18HC; (2) Placing the PCM layer between the double-layer capillary bundle yields better results compared to other arrangements; (3) Optimal energy saving is achieved when the outer capillary bundle is positioned 6 mm away from the outer surface and the inner capillary bundle is positioned 8 mm away from the inner surface; (4) The optimal thickness of the PCM layer is 10 mm; (5) The optimal flow velocity in the capillary bundle is approximately 0.04 m/s. Furthermore, long-term operation results based on a typical hot summer and cold winter climate zone reveal that the optimized PCM-DLCB wall provides a 7.80 % increase in indoor heat gain compared to an ordinary PCM wall during winter, and an 18.4 % increase compared to a wall without PCM.

Enhancing PV solar panel efficiency through integration with a passive Multi-layered PCMs cooling system: A numerical study

Photovoltaic (PV) solar cells are at the forefront of sustainable electricity generation technologies, yet they exhibit relatively low efficiency. Typically, less than 20 % of the solar energy absorbed is converted into electrical energy, with the remainder converts into heat. This heat increases the PV panel's operating temperature, negatively impacting its efficiency and life expectancy. To mitigate this, a novel approach using multi-layered phase change materials (PCMs) has been examined in this study. The approach involves integrating organic PCMs (OPCMs) with metallic PCMs (MPCMs), enhancing PV panel cooling efficiency by attaching the multi-layer PCM to the panel's rear. This study, employing ANSYS FLUENT software's solidification and melting model, explores the impact of multi PCM layers thickness and total multi layers thickness on PV cell temperature and electrical efficiency. The analysis reveals that a multi-layered PCMs configuration with a thickness ratio of 15:85 between MPCM (CERROLOW-117® alloy) and OPCM (RT44) significantly decreases temperature rise in PV cells, resulting in a temperature drop of 59.6 °C. This improvement boosts PV panel performance by an average of 35.8 % compared to panels lacking cooling systems during peak sun hours under hot climate conditions characterized by ambient temperatures of 40 °C and high solar radiation exceeding 1000 W/m². This suggests that a carefully optimized PCM layering approach could markedly improve PV system efficiency, offering a practical solution to the overheating problem and extending the operational life of PV installations.

Designing Dual-Responsive Drug Delivery Systems: The Role of Phase Change Materials and Metal-Organic Frameworks.

Stimuli-responsive drug delivery systems (DDSs) offer precise control over drug release, enhancing therapeutic efficacy and minimizing side effects. This review focuses on DDSs that leverage the unique capabilities of phase change materials (PCMs) and metal-organic frameworks (MOFs) to achieve controlled drug release in response to pH and temperature changes. Specifically, this review highlights the use of a combination of lauric and stearic acids as PCMs that melt slightly above body temperature, providing a thermally responsive mechanism for drug release. Additionally, this review delves into the properties of zeolitic imidazolate framework-8 (ZIF-8), a stable MOF under physiological conditions that decomposes in acidic environments, thus offering pH-sensitive drug release capabilities. The integration of these materials enables the fabrication of complex structures that encapsulate drugs within ZIF-8 or are enveloped by PCM layers, ensuring that drug release is tightly controlled by either temperature or pH levels, or both. This review provides comprehensive insights into the core design principles, material selections, and potential biomedical applications of dual-stimuli responsive DDSs, highlighting the future directions and challenges in this innovative field.

Thermal storage investigation of a two-layered latent-sensible packed bed with PCM and rock spheres

To improve the thermal performance of concentrated solar power (CSP) plants, this study establishes a novel two-layered latent-sensible packed bed to extend the application scope. The major innovation lies in the combination of nitrate-encapsulated phase change material (PCM) capsules and rock spheres in a two-layered configuration, which enhances operational efficiency and minimizes heat transfer temperature differences. A transient concentric-dispersion model is used for numerical simulations to study temperature evolution, thermocline temperature configurations, liquid fraction, sensible and latent energy storage, exergy rate, and exergy efficiency. Four configurations were evaluated: two-layered packed beds with PCM and rock spheres (Cases A and B) and single-layered packed beds with either PCM or rock spheres (Cases C and D). The analysis focuses on the dynamic behavior of thermal energy exchange within the PCM and rock sphere layers, highlighting the advantages and limitations of each configuration. The results show that the two-layered configurations have lower thermocline degradation and higher thermal efficiency. Specifically, the heat storage capacity increased by 15.18 MJ in the two-layered configurations. The exergy input time extended to 350 min in Case A and 342 min in Case B, compared to 260 min in Case C. Results indicate that this hybrid approach significantly reduces thermocline degradation and enhances the overall energy storage capacity and efficiency. The proposed two-layered latent-sensible TES showed higher exergy efficiency and energy storage density than both single-layered LHTES and SHTES, demonstrating improved thermal storage performance.

Multizone Modeling for Hybrid Thermal Energy Storage

This study presents a one-dimensional mathematical model developed to simulate multi-zone thermal storage systems using phase change materials (PCMs). The model enables precise analysis of temperature distribution in the layered storage based on several PCM configurations and properties. It is distinguished by its adaptability to various tank geometries and the number of PCM capsules, enabling its application under diverse operating conditions. By simplifying the implementation of heat transfer processes that depend on the shape of the capsule and the thermal properties of the PCM, the computation time can be reduced to a level that makes simulations over longer periods feasible. Experimental validation confirmed the accuracy of the model, with deviations below 6%, underscoring its practical applicability. The study demonstrates that individual layering in the storage tank can be achieved by filling it with PCMs of different melting points without compromising the maximum storage capacity. It is shown that including a PCM layer can maintain the outlet temperature 20% longer while storing 14% more energy. The results point out the model’s potential to improve the performance of thermal storage systems through targeted PCM layer configurations. The model serves as the basis for the planning and optimization of these systems.

Thermal performance assessment of the dynamic rotating latent-energy-storage envelope (DRLESE) during winter

The conventional latent-energy-storage-envelope relies solely on the phase changes of Phase-Change Materials (PCMs) to regulate heat transfer, thereby lacking the effectiveness in active indoor heating or cooling. To overcome this technical barrier, the Dynamic Rotating Latent-Energy-Storage Envelope (DRLESE) was proposed to achieve active indoor heating by rotating the PCM layer. The DRLESE can absorb solar gain efficiently and release thermal energy directly indoors. In order to assess the application efficiency of DRLESE, two high-insulation walls incorporating a PCM layer were constructed, with the static one serving as a reference. A numerical heat transfer method was employed and verified an experiment. The numerical results demonstrated that compared to the Static Latent-Energy-Storage Envelope (SLESE), the DRLESE system can release stored thermal energy directly indoors by rotating the PCM layer near the interior, resulting in a released heat flow ranging from −22W/m2 to −80W/m2. However, due to differences in the heat release environment, DRLESE exhibits a lower thermal release rate leading to a reduction of up to 33.8 %∼34.8 % in its thermal release and storage capacity. The DRLESE not only limits thermal dissipation from outdoors but also provides indoor heating, while it provides the thermal energy per unit area to minimize the cooling load of the SLESE with 10.39 m2∼14.10 m2. Finally, it is identified on the present deficiencies and limitations for further the comprehensive investigations.