Phase Change Material Material Research Articles

Controlling Temporally and Spatially Homogeneous Temperature Distribution of Paper Substrates by Biogenic Phase Change Hybrid Material Coatings

AbstractHere the performance of phase change material (PCM)‐coated paper made from unbleached kraft pulp is introduced. The applied PCM consists of a mixture of ethylene glycol distearate (EGDS), a well‐known PCM wax material, and a fully substituted cellulose stearoyl ester (CSE). Transfer of the PCM material onto/into paper is achieved by spray as well as blade coating of EGDS + CSE mixture. It is shown that the kind of coating method used does not interfere with observed PCM properties. The significantly higher melt viscosity of the EGDS + CSE blends ensures that the EGDS wax is not bleeding out of the paper, which avoids the use of further encapsulation processes. The PCM behavior, as observed by thermal load measurements, and the thermal buffering of the coated paper is a function of the applied mass of the PCM material applied. The thermal retention exhibited a quasi‐isothermal behavior at ≈65 °C with EGDS + CSE coatings. These effects can offset fluctuations in temperature, and the PCM papers can be employed to achieve a more uniform temperature setting. PCM‐modified papers are therefore interesting candidates for paper‐based packaging or for use in paper‐based sensors, where overheating can strongly affect reliability of results.

Recent Progress on Air, Liquid, PCM, Heat Pipe, and Hybrid Modes of Thermal Management in Lithium-Ion Batteries

This study emphasises lithium-ion batteries, which have been the subject of extensive research due to their wide range of benefits, including extended life cycle, minimal discharge, and high energy density. However, the temperature sensitivity of the batteries presents a notable obstacle that can negatively impact their performance and longevity when operating under extreme conditions. To overcome this challenge, implementing an effective battery thermal management system (BTMS) is imperative. Battery thermal management is crucial for ensuring the safety and longevity of lithium-ion batteries, especially in high-demand applications like electric vehicles. This comprehensive review explores a variety of BTMS technologies, including air-cooling methods, liquid-cooling techniques, heat pipes, and PCM materials. While air-cooled BTMS is a safe and straightforward design, its lower heat capacity and thermal efficiency limit its use to low-capacity batteries. However, forced air-cooled BTMS is an excellent solution for high charging/discharging rates, as air flows through channels within the battery packs to optimize cooling. Liquid-cooled BTMS also shows promise, although designers must ensure the sealing cover is secure to prevent leaks. Heat pipes (HP) offer a unique approach to controlling battery temperature, while Phase change materials (PCM) thermal management is notable for its ability to absorb significant heat by latent heat. Hybrid cooling combines fins, nanofluids, PCM, and microchannels-based cooling and can significantly enhance battery performance under high charging/discharging rates. Furthermore, lithium-ion batteries are extensively used in various applications, including the Electric vehicle industry. Keeping the lithium-ion battery temperature within the optimal range is important and is accomplished by a suitable BTMS. Different methods, such as air cooling, Liquid cooling, Heat pipe, and PCM materials, are used in BTMS. An effective thermal management system and efficient battery model are absolutely necessary. Each of the techniques in BTMS has its own benefits and drawbacks. The effectiveness of thermal management configurations and methods can vary. Thus, evaluating performance and optimal configuration is crucial before implementation.

Solar Dryers: Technical Insights and Bibliometric Trends in Energy Technologies

This review article provides a comprehensive analysis of the technical advancements and research trends in solar drying technologies for agricultural products. The study encompasses various innovations in energy storage systems, including phase change materials (PCMs) and the use of computational fluid dynamics (CFD) for optimizing the drying process. Through a bibliometric analysis of 126 scientific papers published between 1984 and 2024, five major research clusters were identified: energy generation, heat transfer, thermal storage, simulation modeling, and the integration of hybrid systems. The results demonstrate a marked increase in scientific output over the past decade, emphasizing a growing interest in the sustainable use of solar energy for drying applications. Key findings highlight that while PCM-based storage solutions significantly enhance the thermal stability of dryers, the high implementation costs and technical complexities limit their adoption, especially in small-scale operations. Similarly, CFD models have proven effective in optimizing air and temperature distribution within dryers; however, their performance is hindered by real-world fluctuations in solar radiation and humidity levels. To address these limitations, future research should focus on the development of cost-effective PCM materials and the improvement of CFD models for dynamic environmental conditions. The review concludes by emphasizing the importance of interdisciplinary collaboration in the design and application of these technologies, recommending the inclusion of real-world case studies to better illustrate the practical implications and economic benefits of solar drying technologies for agricultural production.

Experimental correlations to predict the cooling performance and compressor energy consumption of domestic refrigerator with phase change material

ABSTRACT The phase change material technology is continuously evolving in commercial market. In order to develop/design PCM modules of different capacity and different PCM material, it is necessary to develop the equation which will provide required information for development of PCM module. This paper establishes correlations to predict backup time and equivalent energy consumption of domestic refrigerator based on experimental data of testing of PCMs, potassium chloride (KCl), sodium chloride (NaCl), and sodium fluoride (NaF) dissolved in water for PCM masses varying between 0 and 1.75 kg in both closed door and door opening conditions. This paper investigates the impact of incorporating a phase-change material (PCM) on the cooling performance and energy consumption of a domestic refrigerator. The PCM module, filled with potassium chloride (KCl), sodium chloride (NaCl), and sodium fluoride (NaF) dissolved in water, is strategically placed on the contact surface of the refrigerator’s evaporator coil. The utilization of PCM aims to mitigate cabin temperature fluctuations and reduce overall energy consumption. Through experimental evaluation, the study assesses the effectiveness of different phase-change materials in enhancing the cooling performance and energy efficiency of the domestic refrigerator. The findings reveal that the incorporation of phase-change material significantly improves the cooling performance, as evidenced by the extended backup time during power cut-off and a reduction in compressor energy consumption. The tested phase-change materials, including KCl, NaCl, and NaF, demonstrate varying impacts on performance parameters. The backup time for closed-door tests is 1.83 – 1.03 times longer than that for door opening tests, respectively. The backup time of door opening tests is shortened due to heat entered to the cabin for all masses, between 45.45% and 3.23%. The backup time is increased by the masses of PCM KCl between 14% and 155%, the masses of PCM NaCl between 18% and 159%, and the masses of PCM NaF between 27% and 182%. The equivalent energy consumption for door opening tests is 1.12–1.02 times larger than that for the closed-door tests. The correlation equation established based on the existing experimental data can be used to accurately predict the backup time and equivalent energy consumption of refrigerator for tested PCM of any mass within the interval of 0 Kg to 1.75 Kg with ± 10% accuracy.

Alkali alkanoate ionic liquids for thermal energy storage at mid-to-high temperature: Synthesis and thermal–physical characterization

Thermal energy storage is gaining much attention and experiencing a renascence in last years. In this sense, storing thermal energy in form of latent heat is of special interest due higher energy density, lower energy losses and higher energy efficiency. To store thermal energy as latent heat the presence of a phase change material (PCM) is needed and its performance the key for its implementation in a thermal energy storage (TES) system and the temperature at which the phase change takes place, low (<150 °C) or high (>150 °C) temperature, will condition the application of a given PCM. In this context, the development of PCM materials to store latent heat at mid-to-high temperature in between 150 °C and 350 °C is of special interest e.g., in the field of concentrated solar power or heat recovery. There are already some solid–liquid phase change materials working in this range of temperature e.g., sugar alcohols, aromatic organic compound, inorganic salts, or blend of inorganic salts but all of them present different drawbacks, such as vapor pressure, degradation, low thermal conductivity, corrosion, etc. In consequence, there is a need to explore new PCM materials in this range of temperature applications. In this context, ionic liquids could play a key role in the development of novel PCMs due to their intrinsic properties. Indeed, ILs are gaining increased attention in the field of thermal energy storage in the last years but mainly in the low temperature range (<150 °C) remaining their application in the mid-to-high temperature range in between 150 °C and 350 °C underestimated. In this work, we prepared six different alkali alkanoate ionic liquids, namely [Na][MeOC2], [K][MeOC2], [Na][MeOC3], [K][MeOC3], [Na][MeOC4] and, [K][MeOC4] by direct reaction between the desired methyl methoxycarboxylate ester with NaOH or KOH. The prepared ionic liquids were structurally characterized, and their thermal–physical properties evaluated. Five of them but [K][MeOC3] showed good enthalpy values ranging from 119 J/g to 197 J/g and four of them [Na][MeOC2], [K][MeOC2], [Na][MeOC4] and, [K][MeOC4] have showed excellent thermal stability above 380 °C. In addition, these four ionic liquids have successfully passed the cyclability test showing no significant enthalpy losses (between 0 % minimum and 7 % maximum) after 50 heating/cooling cycles compiling with the cycling category F of the RAL-GZ 896 (Quality Association PCM). All in all, these prepared ionic liquids surpass sugar alcohols in terms of cyclability and thermal stability and are comparable with the inorganic salts e.g. NaNO3 employed in the studied range of mid-to-high temperature (150–350 °C).

Optimized manufacturing process of encapsulating phase change materials in granular form using coating materials and methods

ABSTRACT This paper focuses on the development of leak-proof phase change materials (PCM) granules, industrially. Stearic acid (SA) is chosen as the PCM material. The paper first describes the method of impregnating SA into a porous graphite matrix resulting in a composite powder. Various combinations of polymeric coating materials are chosen and their reactivity with the SA is studied. Further, the best polymeric coating was then applied to the composite powder. Three methods are discussed - matrix encapsulation, pan coating, and fluidized bed coating. The granules obtained by all three methods, after coating are then characterized. The thermal properties are compared by measuring phase change temperature, latent heat, and leakage. The melting point of the granules was found to be in the range of 63-65 ℃ indicating that PCM has not undergone any chemical degradation during the processing. Surface morphology was studied to understand the uniformity of the coating.

Phase change material properties identification for the design of efficient thermal management system for cylindrical Lithium-ion battery module

Performance and life of Lithium-ion battery packs in EVs and energy storage applications are limited by the thermal profile of cells during its life. Passive cooling technique based on Phase Change Material (PCM) is employed for mitigating thermal issues associated with Lithium-ion cells. The challenge with PCM materials is the trade-off between its latent heat of fusion, thermal conductivity and specific heat. Detailed CFD analysis is carried out to study the impact of PCM thermal properties on battery pack thermal profile and provide guidelines for PCM properties selection and usage of existing PCM materials. Impact of critical PCM properties such as latent heat (100–250 kJkg−1), thermal conductivity (0.2–23 Wm−1K−1), melting temperature and thickness of PCM material on thermal performance of a battery module during rapid discharge rate of 25 A (3.2C) is investigated. Battery module maximum temperature (Tmax) reaches 54°C and temperature difference (∆T) to 5.5°C while operating at 35°C with 124 kJkg−1and 0.2 Wm−1K−1. It is found that, PCM with higher latent heat (≥ 175 kJkg−1), thermal conductivity (≥ 3 Wm−1K−1), PCM thickness (≥ 3 mm) and appropriate phase change temperature 41-44°C exhibit improved heat dissipation for high discharge rates by effectively reducing the Tmax to 44.4°C and ∆T to 2.4°C (25 A and 35°C ambient). Further, ways to mitigate low latent heat capacity and thermal conductivity of PCM through increasing PCM material usage (i.e. inter cell distance) is emphasized. Results of the present study can be considered as a design tool for PCM development engineers which could be cost effective both in-terms of development time and effort.

Synergistic Effects of Heated Walnut Shell Powder and Reduced Graphene Oxide in Paraffin Wax Composites for Marine Thermal Applications

The study focuses on creating and analyzing paraffin wax composites enriched with heated walnut shell powder and reduced graphene oxide nanoparticles. Experimental procedures include careful blending of materials to form homogeneous mixtures, followed by analysis using techniques such as thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The composites show improved thermal properties compared to pure paraffin wax, with increased melting temperatures, heat of fusion, and thermal conductivity. The study also examines density and thermal diffusivity, providing insights into thermal behavior. Additionally, it ensures the corrosion resistance of nano-enhanced bio-based phase change materials (PCMs) for marine engineering through thorough material selection, corrosion testing, and long-term exposure studies simulating seawater conditions. The study evaluates environmental impacts, toxicity, and compliance with standards and proposes mitigation strategies like protective coatings and encapsulation techniques. Overall, the research contributes to developing environmentally sustainable PCM materials for marine applications and offers insights into their thermal behavior for thermal energy storage and management.

A study on a battery pack in a hybrid battery thermal management system integrating with thermoelectric cooling

An inherent limitation of lithium-ion batteries is their restricted use within a specific thermal working range. To address this problem, efficient battery thermal management systems (BTMS) are required to dissipate the heat created by the cells in the battery pack. In order to control the maximum temperature and minimise the temperature difference through the battery pack during a 5C discharging process, this study investigates a phase change material (PCM)-porous battery thermal management system, cooled by thermoelectric coolers (TEC) on its walls. To calculate the heat generation of Li-ion batteries, the equivalent circuit model (ECM) is employed. In this model, a battery is made up of a set of electric elements, including R–C pairs. Different PCM and porous materials are studied to determine the most suitable material for controlling the thermal behaviour of the battery pack. The study reveals that the solidus temperature and latent heat of PCM are the two most crucial factors in PCM selection. A thermoelectric cooler is an instrument that uses electrical energy to transfer heat from one side of the device to the other, depending on the current direction. The study examines the use of a TEC (thermoelectric cooler) under various ambient temperatures and applied voltage differences. The results demonstrate that adjusting the voltage difference between the two TEC heads from 900 to 1500 mV, while the ambient temperature ranges from 303 K to 323 K, allows for achieving a cold plate temperature between 288 K and 308 K. The designed BTMS is tested in various TEC positions, and it is shown that when TECs are used on side walls, the maximum temperature of the battery back can decrease up to 1 K, and better temperature uniformity is observed.

Improving the performance of a shell and tube latent heat thermal energy storage through modifications of heat transfer pipes: A comprehensive investigation on various configurations

The modification of the geometric configurations of heat transfer pipes in shell and tube Latent Heat Thermal Energy Storage (LHTES) systems not only enhances the melting process of the phase change material (PCM) but also improves the overall performance of these systems. This study aims to investigate ways to enhance the performance of LHTES systems by employing heat transfer pipes with various fin and twisted tape arrangements in a horizontal orientation. The Finite Volume Method and Enthalpy-Porosity method are employed to simulate the melting process. Stearic acid is used as the PCM material, while water serves as the heat transfer fluid. Eight different geometric configurations are modelled in the LHTES system: base case, horizontal fins, vertical fins, helical fins, horizontal tape, vertical tape, twisted tape and helical fins with twisted tape. The results show that within the time range of 0 and 29 min, the combined configuration of helical fins with twisted tape consistently demonstrates the fastest melting process. After 29 min, the configuration with vertical fins exhibits a marginally faster melting process than the combined configuration of helical fins with twisted tape. The configurations involving tapes also contribute to accelerated melting, although to a lesser extent than those with fins. Particularly, twisted tape proves highly effective in facilitating faster melting. The complete melting process times for configurations with vertical fins, helical fins, and combined helical fins with twisted tape are 38.7 %, 23.5 % and 32.7 % faster compared to the base case which is ∼69 min. Among the configurations, using tapes results in higher flow resistance and surface area compared to the base case. The attractive features of these configurations make them ideal for creating efficient and space-saving energy storage systems. This study provides crucial insights into essential heat and mass transfer processes, which can be leveraged to develop advanced LHTES systems for enhanced performance and sustainable energy solutions.

Heat of hydration in ultralight cementitious foams incorporating metakaolin and microencapsulated phase change material

The paper presents the results of a study on the hydration heat of ultralight cementitious foams envisaged as insulation materials for building envelopes. The examined porous foam-cement material was additionally enhanced by embedded microencapsulated phase change material (PCM) to improve the desired thermal properties of the material. The heat emission and heat flow were measured at 20 °C and 30 °C for 168 h using the isothermal calorimeter. The experimental study comprised composites with dry densities of 240 kg m−3 and 480 kg m−3, two concentrations of protein-based foaming agent (2% and 4%) and two dosages of the embedded PCM material (10% and 20%). The reference composite without PCM was also tested. The effect of the necessary admixtures used to achieve the stability of ultralight cementitious foams was also examined. The results showed that hydration in ultralight foam-cement composites is retarded, and the values of heat released are lower than those of the paste used to produce the composites. In this regard, the main factors contributing to the lower heat released and its lower rate are the excess water from the foam, the dosage of the foaming agent and the admixtures introduced to achieve the stability of the ultralight composite. The stabiliser was found to be the most retarding admixture. Considering PCM, which was added at 10% and 20% of the paste volume, a rather low influence on the course of the hydration process was observed due to the overall composition of ultralight cementitious foams specially modified for each assumed content of PCM.

Using phase change material nanoparticles for thermal storage to protect healthy tissues by hyperthermia method assisted by a magnetic field for cancer tissue ablation

Magnetic fluid hyperthermia (MFH) is a promising cancer treatment due to its minimal invasiveness and limited adverse effects. It targets tumor cells by heating them to a specific temperature, utilizing heat generated by magnetic nanoparticles (MNPs) in response to an external magnetic field. This study is a numerical theoretical research, in which tissue cancer is embedded with MNPs and healthy tissue is embedded with phase change materials (PCMs). Among different materials, PCM paraffin wax is selected because it is recognized as one of the most functional types of paraffin-based PCM, known for its high thermal storage capability, and is a also subset of non-toxic organic PCM materials. The novelty of this work lies in using a magnetic field produced by a solenoid to approach real conditions and using phase change materials as energy storage materials to protect healthy cells. The finite element method (FEM) by COMSOL Multi-physics commercial software is used to solve governing equations. The effect of using PCMs on tissue temperature distribution is carefully studied. The results of this study show that the use of PCM significantly reduces the temperature of healthy tissues around the tumor in a controllable temperature range, leading to less tissue damage when MNPs release heat. The effect of PCMs on tissue temperature distribution increases with the rise of their volume fraction. The results show that moving the tumor from the center to the outside of the coil decreases the temperature inside the tumor, and the temperature distribution becomes non-uniform. Results from this study can be used to add PCM for MFH to control the temperature of tissue more accurately.

Level-set topology optimization of heat sinks with phase-change material

Phase-change materials (PCMs) excel in storing significant thermal energy through the latent heat of fusion during phase changes. However, they often suffer from low thermal conductivity, requiring the incorporation of materials with higher thermal conductivity to overcome this limitation. In this study, we employ the level-set method to topologically optimize the distribution of both PCM and high thermal conductivity materials within heat sinks.The heat transfer process is modeled as an unsteady diffusion problem, with PCM integrated using the apparent heat capacity method. The finite element method, implemented using FEniCS, is utilized to compute the temperature distribution at each time step. The optimization problem is solved using ParaLeSTO, a modular topology optimization software written in C++, seamlessly interfacing with FEniCS through its Python interface.To compute boundary point sensitivities for level-set topology optimization, the discrete adjoint method is employed, combining a perturbation scheme with automatic differentiation. The proposed methodology is first applied to a two-dimensional example of temperature oscillation minimization with a heat flux boundary condition, drawn from existing literature. Subsequently, a two-dimensional example with multiple volumetric heat sources is studied, followed by an extension to a three-dimensional design domain.Comparisons with optimized designs without PCM, serving as a reference, highlight the superior thermal performance of heat sink designs with PCM. The results showcase a maximum temperature reduction of up to 42%, a mean temperature reduction of up to 42%, and a temperature variance reduction of up to 94%. This research contributes to heat sink design by offering discrete solutions that significantly improve thermal performance as compared to designs without PCM. Its impact extends to addressing crucial challenges in thermal management across various applications, including automotive cooling systems, aerospace components, and consumer electronics.

Influence of Different Melting Points of Phase Change Material on Photovoltaic Phase Change Materials System Performance: An Energy, Exergy, and Environmental Point of View

The photovoltaic (PV) module extracts and converts solar irradiation energy into electrical power in a sustainable and renewable manner. The substantial upswing in the temperature of the PV panel occurs while conversion predominantly impacts its performance and reduces efficiency. To resolve this issue, three different organic phase‐change materials (PCMs), OM29, OM35, and OM42, are proposed for cooling the PV panel as a thermal energy storage medium. The energy and exergy performance of PV panels with and without PCM are compared through experimental investigation to study the influence of different melting points of PCM with reference PV system (PVr). It is identified that the average PV panel temperature can be significantly reduced by incorporating PCM materials (OM29, OM35, and OM4), which are 12.7%, 21.53%, and 17.71% lower than the PVr system. The average electrical efficiencies of PV‐PCM–OM29, PV‐PCM–OM35, and PV‐PCM–OM42 are 10.96%, 10.77%, and 11.66%, which are 4.07%, 6.38%, and 4.91% higher than PVr system. Similarly, the average exergy efficiency is 4.62%, 5.06%, and 5.57% higher. The incorporation of PCM (OM29, OM35, and OM4) as a cooling mechanism effectively mitigates the CO2 3.70, 5.67, and 4.46 tons of CO2 throughout its lifetime and contributes to the sustainable development goal 7.

Residential Micro-CHP system with integrated phase change material thermal energy storage

This paper presents an analysis and experimental investigation of the effect of integrating Phase Change Material (PCM) within a heat exchanger within a Micro Combined Heat and Power (Micro-CHP) system intended for residential applications. A commonly used Micro-CHP layout is replicated in a test rig to characterise the performance of two alternative heat exchanger arrangements. The first is a conventional arrangement where the exhaust gas produced by the prime mover is directed to an air-to-water heat exchanger to heat water and store it in a tank. In the second arrangement, PCM material is encapsulated within specially designed compartments in a heat exchanger to store part of the exhaust thermal energy from the prime mover while heating the water in the storage tank. The time needed to heat the water and discharge heat is compared for both cases, as well as the amount of thermal energy stored during the same operating period. The study also explored the potential to improve the designed unit by using different PCM materials. The test results show that adding 4.7 L capacity paraffin compartments within the heat exchanger extended the discharge time of the hot water by over 400 %, which reflects a marked improvement in the heat storage capacity of the system. This would result in a significant increase in the viable operating period of a CHP system. The one-dimensional analysis revealed that replacing the paraffin with ClimSel C58 PCM can reduce the charging time of the water tank by around 54 % improve the heat storage capacity by factor of 2.35 comparing to Paraffin. The proposed heat exchanger with encapsulated PCM has a potential in other applications such as storage of excess renewable energy or integration with heat pumps to improve matching of supply and demand and thus flexibility of an energy system with integrated intermittent renewables.

The Morphological and Thermal Characteristics of Hollow-Glass-Microsphere-Coated Phase Change Material–Cow Pie Embedded Recycled Plastic Tiles for Cool Roofs

This study addresses the global plastic waste crisis and the urban heat island effect by developing an innovative solution: recycled plastic roof tiles embedded with phase change material (PCM) and coated with hollow-glass-microsphere-based white paint. The samples were fabricated with cow pie fibers, OM37 and OM42 PCM materials with different wt./vol. values, i.e., 15/50, 20/50, 25/50, 30/50 ratios. The fabricated tiles were coated with hollow glass microspheres to provide a reflective layer. The tiles’ effectiveness was evaluated through morphological examination and thermal analysis. The SEM analysis revealed an excellent bonding ability for the PCM blend, i.e., OM37 and OM42 at a 20/50 ratio (wt./vol.) with cow pie fibers. Adding cow pie fibers to the PCM shifted the melting points of OM37 and OM42, indicating an increased heat storage capacity in both blends. The thermal conductivity results revealed decreased thermal conductivity with an increased cow pie fiber percentage. The recycled plastic roof tile of the PCM composite at a 20/50 (wt./vol.) ratio showed good thermal properties. Upon testing in real-time conditions in a physical setup, the roof tiles showed a temperature reduction of 8 °C from outdoors to indoors during the peak of summer. In winter, cozy temperatures were maintained indoors due to the heat regulation from the roof.

Recent trends on energy-efficient solar dryers for food and agricultural products drying: a review

AbstractThe energy efficiency enhancement of solar dryers has attracted the attention of researchers worldwide because of the need for energy storage in solar drying applications, which arises primarily from the irregular nature of solar energy that leads to improper drying which will reduce the quality of the products being dried. This work comprehensively reviews the state-of-the-art research carried out on solar dryers for energy efficiency enhancement using various alternative strategies, including hybrid solar dryers that use auxiliary heating sources, such as electric heaters or biomass heaters, solar-assisted heat pump dryer, use of desiccant materials, and heat storage systems that use both sensible and latent heat storage. The advent of phase change materials (PCM), such as thermally and chemically stable PCMs, for long-term storage, bio-degradable and bio-compatible PCM materials to alleviate the negative environmental impact of conventional PCMs is also presented. The performance parameters considered for evaluating dryers include the maximum temperature attained inside the drying chamber, drying time and efficiency, specific moisture extraction rate (SMER), energy and exergy efficiency and CO2 mitigation effect. The factors considered to analyze the PCMs application in solar dryers include cost and sustainability of PCMs, and both energy and exergy analyses of dryers using PCMs. The gaps in current knowledge and future scope for further improvement of solar dryers are also elucidated. Graphical abstract

Numerical investigation on heat transfer characteristics in battery thermal management with phase change material composited by toroidal porous medium

The introduction of a high-thermal-conductivity porous medium stands as an effective strategy for enhancing the heat transfer rate within battery thermal management using phase change material (PCM). In this study, we have delved into the investigation of heat transfer augmentation in battery thermal management through the implementation of toroidal porous medium. The exploration encompasses the effects of Rayleigh numbers, thicknesses of the toroidal porous medium, different kinds of porous medium and PCM. By comparing the liquid fraction, dynamic temperature and the latent heat ratio, we found the effect of Rayleigh number and thickness of porous medium on the property of the battery thermal management. The results indicate that by applying thicker toroidal porous medium could weaken the heat accumulation derived by high Rayleigh numbers. Case of d = 0.273R exhibits superior performance for a significant portion of the entire process compared to other cases with thickness of 0.235R, 0.326R, 0.408R and uniform distributed, while the dominant position is difficult to hold due to the heat accumulation. The conclusion is universal for different porous medium and PCM materials. The optimal distribution of porous medium should seek a balance between enhancing heat conduction and weakening thermal convection. A more scattered distributed porous medium could weaken the effect of heat convection and rises the latent heat ratio.

Revolutionizing solar water distillation: maximizing efficiency with pyramid solar stills enhanced by fins, evacuated tubes, nanomaterial, and phase change materials—a comprehensive review

Abstract The availability of water and energy is crucial for human survival, yet rising industrialization and population growth have escalated demand, particularly in developing economies. Despite efforts to address water scarcity, contamination persists, leading to widespread diseases. Conventional purification methods like reverse osmosis are effective but expensive and energy-intensive while boiling exacerbates air pollution. In this context, solar still systems present a promising solution, harnessing abundant sunlight to distill seawater into drinkable water. By integrating phase change material (PCM) and sensible heat storage, these systems can enhance efficiency and reduce energy consumption. This article explores the optimization of solar still systems through the selection of suitable PCM and sensible heat storage materials. The primary objectives are to improve distillation efficiency and heat recovery, making the process more eco-friendly and cost-effective. By addressing water scarcity and energy consumption simultaneously, these optimized systems offer a sustainable approach to water production, particularly in regions with ample sunlight. Through a comprehensive review, this research aims to advance the understanding of solar still technology and facilitate its widespread adoption, ultimately contributing to global efforts toward water security and environmental sustainability.

PERFORMANCE IMPROVEMENT OF CIRCULAR PARABOLIC CONCENTRATING SOLAR COOKER USING NANO-MIXED BINARY SALT PHASE CHANGE MATERIAL

A multi-objective investigation has been carried out for a parabolic concentrator-type solar cooker with the use of nano-mixed binary salts phase change material (PCM) materials. Binary salts like NaNO&lt;sub&gt;3&lt;/sub&gt; and KNO&lt;sub&gt;3&lt;/sub&gt; are mixed with alumina (Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;) nanoparticles in the ratio of 0.5&amp;#37;, 1&amp;#37;, and 1.5&amp;#37; by weight. Properties such as thermal conductivity, specific heat, melting point, and thermal diffusivity are computed experimentally. Two food items, namely rice and dal, are selected for cooking purposes. The experimental results obtained from this research work show some promising returns. As compared to the plain PCM, the nano-mixed PCM reduces the cooking time, and with an increase in the addition of nanoparticles in PCM, the overall cooking time for both food items decreases. A difference of 5-6 minutes has been observed between plain PCM and nano-mixed PCM cooking. Another important observation made during this study is that the thermal properties of PCM material are affected by the addition of nanoparticles. The thermal conductivity increases by almost 10&amp;#37; and thermal diffusivity increases by 20&amp;#37;. The melting point of PCM decreases by 22&amp;deg;C, and the specific heat decreases by 12&amp;#37; and 17&amp;#37; at a temperature of 100&amp;deg;C and 250&amp;deg;C, respectively. Finally, it is concluded that the use of alumina nanoparticles in the binary salts PCM improves the thermal storage capacity of the PCM material.