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The appropriate storage, transportation, and utilization of wood-based fuels, including woodchips, pellets, and sawdust, in the energy production process, depends on their efficient drying. Traditional drying methods include limitations such as high thermal losses, inefficient heat transfer, and sustainability issues. These barriers, coupled with the high costs and complexities of maintaining the desired moisture content, underscore the need for innovative solutions. This study introduces a novel approach to wood fuel drying through the integration of phase-change materials (PCMs) with hybrid solar drying systems, aimed at enhancing thermal efficiency and sustainability. Employing coconut oil as the PCM, experiments were performed under a consistent artificial radiation of 755 W m−2. The hybrid system demonstrated the capability to retain approximately 200 watts of useful heat for three hours post-radiation, marking a significant improvement in heat storage. Our findings reveal peak thermal and exergy efficiencies of 30–35% and 13–14%, respectively. An economic and environmental analysis predicts a system lifespan of five years, with the cost of generating one kilogram of hot air at 0.0058 EUR and an annual CO2 emission of 64.09 kg. This research offers a cost-effective and environmentally friendly method for wood fuel drying, presenting a significant advancement for large-scale producers and setting a benchmark for further exploration of wood fuel drying technologies. [ABSTRACT FROM AUTHOR]

Temperature control system based on organic phase change materials (PCMs) has attracted tremendous attention in medical applications owing to the obvious advantages of large heat storage, accurate temperature controlling, ease of modification, etc. In order to fully utilize the advantages of organic PCMs for better application in biomedicine, it is often necessary to encapsulate PCMs to improve their shortcomings (such as instability in form, biosafety, biocompatibility, etc.). Encapsulation techniques of PCMs can achieve the leakage free to enhance the biocompatibility and form stability. In addition, in order to be suitable for different biomedical application scenarios, more functionality needs to be given to PCM microcapsule by using modification, chemical grafting, and polymerization methods. However, in the field of biomedicine, the current researches on the biocompatibility and functional design of organic PCMs in the encapsulation process are relatively fragmented. For the reason, this review systematically summarizes the encapsulation strategies of organic PCMs including core–shell encapsulation, physical adsorption, 3D structure, and covalent bonding. Moreover, the biocompatibility and functionalization design concepts of form-stable organic PCMs are discussed in detail for improving therapeutic effect. In addition, the applications in terms of medical field (e.g., medical textiles, drug delivery, cold chain transportation of pharmaceutical preparation, medical device) are thoroughly presented based on detailed investigations. This review will provide profound insights into the encapsulation and functionalization strategies of form-stable organic PCMs and their medical applications. [ABSTRACT FROM AUTHOR]

This paper proposes a new correlation to evaluate the heat transfer coefficient between a vertical wall containing a phase change material (PCM) and air in a square enclosure. This correlation was determined in order to simulate the transient process during PCM discharge and its effect on the heat transfer inside the cavity without using complex CFD models. A 2D CFD model based on the resolution of Navier–Stokes and energy equations inside the air and the PCM was previously validated. It was used to generate numerical data in order to build the proposed heat transfer correlation. The new correlation is Nu = 0.186 · Ra 0.28 θ 0.271 Ste 0.022 valid for: 10 5 ≤ Ra ≤ 4.310 7 , 0.05 ≤ θ ≤ 1 and 0.05 ≤ ste ≤ 0.6 . The accuracy of the proposed correlation versus the correlations established without phase change is analysed through a simplified model considering only the PCM layer and replacing the air cavity by a flux condition with an appropriate heat transfer coefficient. The relative error being lower than 1%, the new correlation shows a better agreement with the CFD results than existing correlations. [ABSTRACT FROM AUTHOR]

The improvement of heat transfer and energy storage are crucial tasks in many renewable energy applications. The thermal and hydrodynamic performances of a nano-encapsulated phase change material (NEPCM) suspension are investigated under a mixed convective heat transfer regime inside a trapezoidal enclosure. As the host fluid and dispersed NEPCM particles circulate in the enclosure, the nanoparticle cores absorb/release heat and undergo a phase transition process, enhancing heat transfer. The governing equations were scaled into a general non-dimensional format and then solved by the finite element method. The influence of nanoparticles fusion temperature and concentration, as well as the wavy wall characteristics and Richardson number, was addressed on heat transfer. A suitable fusion temperature of the nanoparticles can boost the heat transfer rate by 8%. Furthermore, by employing 5% NEPCM particles at a dimensionless fusion temperature of 0.1, the Nusselt number achieved was 9.05. This marks a significant 37% rise when contrasted with a base fluid, which only had a Nusselt number of 5.7. [ABSTRACT FROM AUTHOR]

This paper aims to compare the performance and efficiency of fluid-driven (FD) and solid-state (SS) systems, which are used for solar heating using parabolic trough. Sodium nitrite (NaNO2) was considered as phase change material (PCM) and both storages had the same storage capacity. To evaluate system performance, constant heating of 1 kW was provided to both systems to replicate solar energy. The fluid-driven system showed maximum efficiency of around 47% as compared to 20% of solid-state system. Although the operating temperature of FD is higher than SS, as temperature increases flow rate of fluid also increases in FD which results in reducing the melting time of PCM. FD shows potential for providing better efficiency and can help utilize solar energy during evening/night when no sun is present. [ABSTRACT FROM AUTHOR]

In high-energy-demand regions, such as the Arctic, the building sector is focused on reducing the carbon footprint and mitigating environmental impact. To achieve this, phase change materials (PCMs) are being investigated for thermal energy storage due to their high latent heat of fusion. However, their limited applications arise from poor thermal conductivity. In addressing this issue, the research delves into the preparation and characterization of nano-PCMs. These materials, synthesized in a laboratory setting, exhibit enhanced thermal performance compared to pure PCMs, attributed to the incorporation of nanoparticles in the material composition. Therefore, in the study, three paraffins with different melting temperatures (10, 15 and 18 °C) are modified by incorporating titanium oxide at various concentrations (0.05, 0.1, 0.2 and 0.5 mass%). Thermal conductivity and latent heat capacity measurements were undertaken using a thermal conductivity measuring apparatus and differential scanning calorimetry, respectively. The aim was to evaluate the enhanced performance of the modified PCMs in comparison with pure PCMs and to assess their suitability for cold climate regions. Results showed that nanoparticle incorporation increased thermal conductivity by up to 37%, albeit with a slight reduction in latent heat capacity of up to 12%. Among the samples, RT18 exhibited the most significant improvement in thermal conductivity, while RT10 experienced a minor decrease in enthalpy values. Ultimately, RT10 was identified as the optimal PCM option for cold climates, as its phase change temperature range aligns with the outdoor temperatures in the Arctic. [ABSTRACT FROM AUTHOR]

Novel designs have been proposed for the phase change material (PCM) heat sink of concentrated photovoltaic (CPV) cells to enhance both convective and conductive heat transfer mechanisms. Trapezoid (with two different thickness ratios) and zigzag geometry designs are suggested for the CPV-heat sink. To enhance the performance, two improving treatments have also been presented for the proposed trapezoid phase change material heat sink, (i) using a baffle and (ii) using two small triangle fins. A set of energy, exergy, economics, and environmental analyses has been established by computational fluid dynamics simulation to compare the performance of the proposed heat sinks with the conventional foamed and finned rectangular heat sinks. The results reveal that a trapezoid heat sink with two small triangle fins reduces the average concentrated photovoltaic temperature by 22 °C, the complete melting time of the phase change material by 1800s (50% reduction), and increases the absorbed heat by 3.13 kJ (7.43% increment), the exergy efficiency by 2.22% (23.9% increment), the generated electricity by 10.55%, and CO2 emission reduction by 10.75% compared to the concentrated photovoltaic with the simple rectangular heat sink. These results of the trapezoid heat sink are very similar to the rectangular heat sink with four long fins but with almost 74.3% lower levelized copper cost. [ABSTRACT FROM AUTHOR]

The low thermal conductivity and liquid-phase leakage of phase change materials seriously hinder their large-scale applications. Porous materials have been identified as an effective way to address the leakage and provide a thermally conductive network. Therefore, we designed an expanded graphite-based multifunctional composite phase change thermal storage materials for personal thermal management and antimicrobial in medical protection. Expanded graphite (EG) was used as the matrix, silver nanowires (Ag NWs) as the functional enhancement materials, and n-octadecane (OD) as the thermal storage materials. OD and Ag NWs were adsorbed in the porous structure of EG by vacuum-assisted impregnation. Finally, EG/Ag NWs/OD were combined with non-woven fabrics (N) by one-step hot pressing method to obtain EG/Ag NWs/OD-N composite with excellent comprehensive performance. With the mass ratio of EG to Ag NWs of 13:7, EG/Ag NWs/OD-N exhibited a thermal conductivity of 2.0130 W m−1 K−1, which was improved by 1070.3% compared with pure OD. EG/Ag NWs/OD-N has a melting enthalpy of 137.85 J·g−1 and a crystallization enthalpy of 128.97 J·g−1. In addition, EG/Ag NWs/OD-N display great antibacterial properties, thermal cycling stability, shape stability, and cycling persistence and showed excellent temperature control in protective clothing applications, offering great potential for large-scale applications. [ABSTRACT FROM AUTHOR]

New phase change materials (PCMs) and ultrasound energy are used to enhance the performance of a photovoltaic (PV) panel. Design of experiment (DOE) method is applied to optimize the surface temperature and output power of the PV panel. In response surface methodology (RSM), volume fraction of glycerol in the mixture of oleic acid and beeswax (0–50%), mass fraction of CuO nanoparticles (0–5%) and solar intensity (500–1000Wm−2) is investigated as three key parameters. At first, an experimental work is conducted in which a U-shape tube is installed inside the enclosure containing PCM with cold water flow. Secondly, CFD modeling is applied to propose a new method for the heat removal from the PCM integrated with the PV panel. A cold water jacket equipped with 1.7 MHz ultrasound waves is inserted instead of the U-shape tube and surrounds the PCM enclosure. Experimental data showed that the PCM with 22.52% glycerol shows the highest PV power. Adding 5%CuO nanoparticles to PCMs caused minimum temperature and the maximum power of the PV panel. Using U-shape tube at optimum condition led to electrical efficiency about 14.33%. CFD data proved that propagation of 1.7 MHz ultrasonic into water jacket led to remarkable reduction in the PV temperature compared to applying the U-shape tube. CFD results demonstrated a good agreement with experimental data with maximum error of 0.97%. [ABSTRACT FROM AUTHOR]

A promising solution for challenges in thermal energy storage (TES) and its management is the use of phase change materials (PCMs). The ionic liquids (ILs) offer a unique properties that make them proper candidates for a number of energy related applications. The IL based 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 ionic liquids (ILs) 2-hydroxyethylammonium, bis (2-hydroxyethyl) ammonium, and tris (2-hydroxyethyl) ammonium laurate as PCMs for the first time operating in the temperature range of 50–150 °C, and offer a safe and inexpensive capacity. The latent heat of fusion values were 147.13, 131.95 and 113.54 kJ·kg−1 for the [HEA]Lau, [DHEA]Lau and [THEA]Lau, respectively. Also, the thermal stability was obtained to be 99% for the [HEA]Lau. Finally, the thermal-to-electric energy conversion is performed using a homemade electronic data gathering and processing instrument with a PCMs (synthesized ILs) container cell and a commercial thermoelectric generator (TEG) device to record the real-time generated electric energy. The recorded output voltage (open circuit case) of TEG device versus time was measured that demonstrated that after turning off the thermal energy source, the proposed system provides the electric energy for a while (more than 2 h). [ABSTRACT FROM AUTHOR]

Phase Change Materials (PCMs) have got widespread attention in thermal energy storage (TES) applications as a result of their wide operational temperature range, high energy storage density, and prolonged life cycle at a reasonable cost. They offer a practical solution to mitigate the building energy consumption, addressing interior temperature fluctuations and enhancing demand-side management through the incorporation of renewable energy and off-peak power. This study focuses on evaluating the influence of PCMs on the performance of radiant heating and cooling systems. Based on conducting a comprehensive review, this study explores the current challenges associated with PCM utilization in these systems. The analysis discloses noteworthy discoveries and potential advantages, paving the way for further investigation and wider adoption of PCMs in the construction industry. Notably, the incorporation of a 10-mm PCM resulted in a 2.4% annual reduction in heating energy consumption in comparison with the existing structures. Furthermore, utilizing a 20–50-mm PCM could yield annual heating energy savings ranging from 7.3 to 15.3%. N-eicosane emerges as the most effective PCM for floor heating, achieving an optimal floor temperature and contributing to a substantial 43% reduction in heating energy consumption. Ultimately, radiant floor systems demonstrate the potential to reduce energy consumption by up to 8% and 4% in a comparison with commercial heating and cooling systems, respectively. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Solar-thermal conversion and thermal energy storage of different phase change materials" published in the Journal of Thermal Analysis & Calorimetry. The correction addresses an error in the introduction section of the original article, where two sentences were incorrect. The corrected sentences emphasize the important role of solar-thermal energy storage in photothermal conversion applications and highlight the significant efforts dedicated to energy storage. The correction was made by the authors of the article. The publisher, Springer Nature, maintains a neutral stance on jurisdictional claims and institutional affiliations. [Extracted from the article]