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A review on phase change materials for different applications
Abstract
Phase change materials (PCMs) are preferred in thermal energy storage applications due to their excellent storage and discharge capacity through melting and solidifications. PCMs store energy as a Latent heat-base which can be used back whenever required. The liquefying rate (melting rate) is a significant parameter that decides the suitability of. PCMs in applications where there is a notable difference in temperature within the device for discontinuous warm storage capacities. A few studies have also been conducted to integrate PCMs in buildings as it upgrades building warm idleness, decreases maximum heat flux. This review paper summarizes some of the applications of PCMs. For future developments, some of the recommendations can be summarised as: in few of the listed applications, stability of the PCM needed to be explored since very few literature are available. The use of multiple phase change materials in a coupled or conjugate applications may also be further explored. In these applications, cost analysis and payback period of thermal storage systems empolyed with phase change materials also need exploration.
... Several examples for each application are listed in Table 1. More information about PCMs' applications can be found in the review proposed by Lone and Jilte [16]. In the present one, the focus is on the determination of some thermophysical properties of PCMs during their solid-liquid phase change. ...
... Table 1. PCM applications and their targeted optimal properties [2,13,16,17]. ...
... Therefore, in their study, they reported the average values and related uncertainty. (16) calorimetry (DSC). As shown in Figure 11, in order to calculate transition enthalpy, one can integrate the area under the heat flow curve (red region) over the temperature range and consider a calibration constant derived from the DSC software. ...
The use of phase change materials (PCMs) in thermal energy storage (TES) applications as a system that can fill the gap between the energy supply and demand has sharply increased over recent years. Due to the dependence of the storage capacity in a TES on the transition (mostly solid/liquid) of PCMs, knowing the thermal properties of PCMs is of high importance. Calorimetric methods have an inevitable role in PCMs’ characterization methods. The most important properties of PCMs that lead us to integrate them in a specific application can be determined by the calorimetric method. These properties are transition temperatures, the enthalpy of transition and the heat capacity. Among the calorimetric methods, differential scanning calorimetry (DSC) is widely available and accurate results can be obtained at a reasonable cost. Furthermore, the thermal stability of PCMs can be determined after a hundred cycles of melting and solidification. The present work proposes an extensive and comprehensive review on calorimetric measurements of PCMs via the DSC method. The objective is to highlight the relevant research with a focus on DSC characterization of PCMs. This review includes studies from 1999 to 2022 and provides a summary of the methods, results and recommendations for future measurements.
... One of the most frequent problems with these batteries is the significant temperature rise caused by high charge and discharge rates and / or continuous use. At high temperatures, beyond the safety limit, battery has its life-cycle and performance reduced, making it necessary to develop a temperature control system to increase the batteries' efficiency and maintain their temperature within the safety limits, that is between 20 and 40°C [159,160].PCM can be incorporated in roofs, doors and side walls of cars and busses to reduce energy loss or gain, improve the thermal performance and reduce energy consumption and gas emissions. A global use of the concept can impact positivelythe world transport energy consumption and emissions. ...
... It was found that the existence of PCM can successfully decrease the temperatures of the material layers below their own temperature limits [158]. Other studies and information on automotive PCM applications can be found in [159,160]. [149] Thermal control and battery thermal management ...
Latent heat materials are widely investigated and successfully used in a variety of important applications as in the building industry and thermal engineering systems. In this paper a comprehensive review on phase change material (PCM) in relatively recent potential application such as photovoltaic (PV) panel cooling, applications in food, automotive; asphalt, and textile industries. The review is divided into seven sections. The first two sections give a general overview of PCMs, their potential in integrating intermittent systems, PCM characterization and enhancement techniques. In the third and subsequent sections applications in the PV panels cooling, food, textile, automotive and asphalt applications are presented. The results showed that application of PCM RT42 in a BiCPV system reduced the temperature by about 3.8 °C and increased the electrical efficiency by 7.7 %. The use of finned enclosures enhanced the performance of PV panels. A finned enclosure decreased the operating temperature by 6.1 °C and increased the efficiency by 5.3 %.The use of nanoparticles (SiC) dispersed into paraffin based PCM showed good thermal performance and increased the electrical efficiency by 13.7 %. Similar benefits are found in the food industry. The use of PCM in food containers reduced the energy consumption, the operational cost, and the emission by 86.7, 91.6, and 78.5 %, respectively. Penetration of PCM in the textile industry is relatively small. Applications in the textile industry showed that for a temperature rise from 20 to 28 °C, common silk took 13 s, the Outlast/silk took 20 s, and the treated fabric took 37 s. Application of PCM in the car industry for cooling batteries, and thermal insulation is continuously growing. It is shown that using PCM decreased the maximum and minimum battery temperature from 56.8 and 48.3 °C to 38.9 and 36.0 °C, respectively. Other application showed that the use of coconut oil as PCM for the thermal control of a vehicle decreased the passenger's cabin temperature by an average of 13 °C, while application on the roof of a parked car during 1 h in a sunny day can reduce the temperature by about 33 °C. The inclusion of PCM in the asphalt mixture can eliminate the destructive bonds that cause aging of the asphalt mixture, contribute to the prevention of low-temperature cracking and decrease the temperature fluctuations in the asphalt binder. This review can be of great help for system designers, practice engineers and researchers in the area of thermal energy storage and PCM based systems. Trends for future research are highlighted.
... One of the solutions to reduce the negative impact on the environment is the application of phase change materials (PCM) [19]. Due to the declining supply of fossil fuels, in the last few years, phase change materials have attracted the interest of a wide range of researchers, organizations, and benefactors as they store thermal energy and release it when needed [20,21]. This is evidenced by research in various fields, such as the electronics industry [22], photovoltaic and solar systems [23,24], hot water systems [25]. ...
... Considering the most important disadvantages of inorganic phase change materials are their corrosion and frequent volume change in some mixtures. In addition, in the case of this type of PCM there is a high risk of subcooling of the substance [21]. [45]. ...
The paper deals with the possibility of using Phase Change Materials (PCM) in concretes and geopolymer composites. The article presents the most important properties of PCM materials, their types, and their characteristics. A review of the latest research results related to their use in geopolymer materials is presented. The benefits of using PCM in building materials include the improvement of thermal comfort inside the building, and also the fact that the additive in the form of PCM reduces thermal gradients and unifies the temperature inside the concrete mix, which can reduce the risk of cracking. The paper also presents a critical analysis related to the feasibility of mass scale implementations of such composites. It was found that the use of PCM in sustainable construction is necessary and inevitable, and will bring a number of benefits, but it still requires large financial resources and time for more comprehensive research. Despite the fact that PCM materials have been known for many years, it is necessary to refine their form to very stable phases that can be used in general construction as well as to develop them in a cost-effective form. The selection of these materials should also be based on the knowledge of the matrix material.
... The field of research in thermochemical materials has been widely disseminated, given its contribution to the energy transition from highly polluting fossil fuels to sustainable energy sources. In parallel, anhydrous compounds exhibiting phase-change properties [19][20][21][22] have also demonstrated potential for use in correlated thermal energy storage systems [23,24]. ...
In this paper, a novel mixed Tutton salt (K0.86Na0.14)2Ni(SO4)2(H2O)6 was successfully synthesized as a single crystal and evaluated as a thermochemical heat storage material. Its thermal and thermochemical properties were correlated with the structure, which was determined by powder X-ray diffraction using the Le Bail and Rietveld methods. The elemental ratio between the K⁺ and Na⁺ monovalent cations was established by energy-dispersive X-ray spectroscopy. Similar compounds such as Na2Ni(SO4)2(H2O)4 and K2Ni(SO4)2(H2O)6 were also synthesized and used for structural comparisons. The (K0.86Na0.14)2Ni(SO4)2(H2O)6 salt crystallizes in monoclinic symmetry with the P21/c-space group, typical of hexahydrate crystals from the Tutton salt family. The lattice parameters closely resemble those of K2Ni(SO4)2(H2O)6. A comprehensive analysis of the intermolecular contacts, based on Hirshfeld surfaces and 2D fingerprint mappings, revealed that the primary interactions are hydrogen bonds (H···O/O···H) and ion-dipole interactions (K/Na···O/O···Na/K). The unit cell exhibits minimal void space, accounting for only 0.2%, indicative of strong atomic packing. The intermolecular molecular and atomic packing are important factors influencing crystal lattice stabilization and thermal energy supplied to release crystallographic H2O. The thermal stability of mixed Tutton salt ranges from 300 K to 365 K. Under the dehydration of its six H2O molecules, the dehydration reaction enthalpy reaches 349.8 kJ/mol, yielding a thermochemical energy storage density of 1.79 GJ/m³. With an H2O desorption temperature ≤393 K and a high energy storage density ≥1.3 GJ/m³ (criteria established for applications at the domestic level), the (K0.86Na0.14)2Ni(SO4)2(H2O)6 shows potential as a thermochemical material for small-sized heat batteries.
... Phase Change Materials (PCMs) have the characteristic of storing and releasing energy through sensible and latent heat at a practically constant temperature (Lawag and Ali, 2022). These can be used in the production of energy storage systems, in buildings, batteries thermal control, temperature control of microelectronics, as well as in the human body and transport (Irfan Lone and Jilte, 2021;Mehari et al., 2020;Mehling et al., 2022). However, these materials have low thermal conductivity, which increases the charging (melting) and discharging (solidification) period and limits their use in the countless possibilities of thermal systems. ...
With the gradual use of renewable energy sources, the demand for storing excess energy generated for later use increases. In this context, thermal energy storage emerges as an interesting alternative, which can occur through sensible and latent heat. Phase Change Materials (PCMs) are known for their ability to perform such storage, where their phase change occurs at a practically constant temperature. However, it is important to use PCMs that are environmentally friendly, enabling the prevention of negative environmental impacts. Therefore, using bio-based PCMs is a promising alternative; however, these materials have low thermal conductivity, which can limit their use. Therefore, it is necessary to implement some methodology that can intensify heat transfer, such as the insertion of fins, nanoparticles and metal foams, which can, in this way, increase heat transfer. Among these alternatives, metal foam appears more attractive as it increases the contact area between the PCM and its surface. In this context, this research experimentally investigated the influence of implementing metal foam under different geometric configurations-uniform Nickel foam and square pin-fin Nickel foam-on the palm wax melting process, selected as bio-based PCM. The results indicate a reduction in the total time of the melting process through the insertion of metal foam compared to pure bio-based PCM, being 8.3% and 4.8% for uniform foam and square pin-fin foam, respectively.
... A PCM can change its state from crystalline to amorphous and amorphous to crystalline repeatedly when thermal, electrical, optical, mechanical, and chemical excitations are applied to it [59], [60], [61]; see Figure 15. Germanium-antimony-tellurium (GST) and germanium telluride (GeTe) are examples of PCMs used for RF and photonics applications [62]. ...
Reconfigurable systems play an important role in the design of reconfigurable wireless communication systems. In the traditional approach, separate transmit and receive pathways are required for every supported communication standard/frequency band for an RF front-end architecture. However, this approach increases the complexity and size of the system. This problem can be solved by employing subsystems, or blocks, that can function across multiple frequency bands and standards or that can reconfigure themselves based on the spectrum. This flexibility can free up finite spectrum resources to enable a miniaturized system. Therefore, microwave subsystems should ideally be reconfigurable and frequency agile in order to handle the vast frequency allocation of the regulated communication bands and the multitude of standards by which these radios must function. Such subsystems would allow for the implementation of new architectures with fewer functional components. Therefore, reconfigurable circuits can be useful for several wireless applications, such as telecommunication and military applications, where new frequency bands are coming or are expected to come. A flow graph for designing reconfigurable circuits is in
Figure 1
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... inorganic PCMs. The up-to-date classification of PCMs based on their phase change behavior and materials composition is shown in Fig. 2 [38,39]. ...
... The type of PCM and its thermal retention properties play a crucial role in determining the energy storage system's heat retention density and thermal transfer efficiency. Table 1 lists standard medium-to-low-temperature PCMs and their physical properties (Fallahi et al., 2017;31;Irfan Lone and Jilte, 2021;Yang et al., 2021;Sinaga et al., 2023). An examination of Table 1 reveals that erythritol has a latent heat value for phase transition of 339 kJ/kg. ...
With escalating energy demands, solar power stands out for its abundance and renewable advantages, presenting a paramount sustainable solution. Herein, we tactically incorporate phase change material (PCM) into solar energy systems, resulting in substantial enhancements in energy storage and utilization. Through numerical simulations, the thermal dynamics and phase change processes associated with various heating methodologies are investigated, aiming to achieve optimal thermal performance and energy efficiency. Detailed analysis of temperature dynamics within the PCM under two distinct heating methods reveals pivotal thermal fluctuations in both the PCM and water during heat release. The results indicate that bottom heating promptly induces rayleigh convection, resulting in a uniform temperature and a stable phase interface, which are desirable for heat transfer. In contrast, central tube heating concentrates heat transfer in the upper PCM layer, leading to an uneven phase interface and thermal stratification. Configurations with two horizontally aligned heating tubes result in a 36% reduction in melting duration compared to the single central tube setup, highlighting enhanced efficiency. Additionally, the bottom heating approach demonstrates improved energy storage efficiency in both the initial and second heating cycles. These findings highlight the potential of PCM-integrated combined heating systems for solar energy capture, confirming their efficiency and practicality in addressing modern household energy demands.
... Up till now, great efforts have been made to address the safety issues of LIBs via air cooling (Sharma and Prabhakar, 2021), liquid cooling (Xu et al., 2022), heat pipe cooling (Smith et al., 2018), and phase change cooling (Irfan Lone and Jilte, 2021;Ling et al., 2014;Zhou et al., 2022). For example, air-cooled systems are cost-effective and have simplified structure, but their cooling efficiency is quite low and not suitable for high-power batteries https Li-ion Lithium-ion BTMS Battery thermal management system XRD X-ray diffractometry DSC Differential scanning calorimetry SEM Scanning electron microscopy applied in electric vehicles. ...
... By harnessing the latent heat associated with the PCM phase change, NEPCMs can effectively regulate temperature fluctuations, enhance heat transfer efficiency, and enable efficient thermal energy storage for subsequent use [24][25][26][27]. A review of the different applications of PCMs is provided in the studies of Lone and Jilte [28] and Jamekhorshid et al. [29]. ...
This study focuses on the thermal behavior and performance of an insulated porous cavity containing square tubes, one as the hot block and the other as the cold block. The cavity is filled with a Nano-Encapsulated Phase Change Material (NEPCM) that combines the advantages of phase change materials (PCM) and nanofluid. The main purpose of this research is to examine the heat transfer mechanisms, phase change process, and overall thermal performance of the system. The governing equations of the NEPCM suspension are transformed into a dimensionless form and solved using the finite element approach. Various parameters, including nanoparticles concentration, fusion temperature, Darcy number, Rayleigh number, and Stefan number, are investigated to assess their impact on the system's thermal and dynamic performance. The results reveal that the optimal heat transfer performance is achieved when the NEPCM fusion temperature is set to 0.5. Moreover, a smaller Stefan number significantly improves the system's performance. Additionally, including NEPCM particles generally improves heat transfer, with a 33% increase in mean heat transfer observed when the volume fraction was raised from 0% to 2%.
... PCMs enable a plethora of applications in tunable nanophotonic structures including tuning the response of infrared antennas and metasurfaces, optical limiting and optical diodes, and tuning quantum two-photon interference, to name a few (Morin, 1959;Wang et al., 2016;Butakov et al., 2018;Wan et al., 2018;Howes et al., 2020;Estakhri and Norris, 2021;Irfan Lone and Jilte, 2021;Wan et al., 2021;Song et al., 2022;Li et al., 2023;Tognazzi et al., 2023). In radiative cooling processes, PCMs such as VO 2 that undergo a metal-to-insulator transition at certain temperatures can potentially act as a switch that has "off" and "on" states (Cui et al., 2018;Ono et al., 2018). ...
In this work, we investigate a class of planar photonic structures operating as passive thermoregulators. The radiative cooling process is adjusted through the incorporation of a phase change material (Vanadium Dioxide, VO 2 ) in conjunction with a layer of transparent conductive oxide (Aluminum-doped Zinc Oxide, AZO). VO 2 is known to undergo a phase transition from the “dielectric” phase to the “plasmonic” or “metallic” phase at a critical temperature close to 68°C. In addition, AZO shows plasmonic properties at the long-wave infrared spectrum, which, combined with VO 2 , provides a rich platform to achieve low reflections across the atmospheric transparency window, as demanded in radiative cooling applications, while also maintaining a compact size. Using numerical analysis, we study two classes of patterned and non-patterned compact multilayer metal-dielectric-metal metasurfaces, aiming to maximize the overall absorption in the first atmospheric transparency window (8–13 µm) while maintaining a high reflection across the solar spectrum (0.3–2.5 µm). Surfaces are initially designed based on a round of coarse optimization and further improved through analyzing the impact of geometric parameters such as size and periodicity of the metasurface elements. Our findings are relevant to applications in thermal regulation systems and passive radiative cooling of high-temperature devices, such as electronic elements.
... 11 Thermal energy can be stored in the form of sensible heat (rocks, sand, gravel, etc.) or latent heat, which is stored via phase change materials (PCMs). 12,13 Compared to sensible heat storage materials, the PCM stores a significant quantity of heat at a specific temperature. 14 Latent heat thermal energy storage (LHTES) systems have 10 to 15 times higher density than sensible heat. ...
A thermal energy storage system must integrate with a solar thermal collector for continuous energy delivery. This article focuses on the identification, preparation, thermo‐physical characteristic studies, and experimental investigation of a novel eutectic hot storage material for solar dryer applications. The identified organic novel eutectic mixture comprises stearyl alcohol and benzamide (SA‐B) with a molar ratio of 70:30. From the differential scanning calorimetry analysis, the melting point and enthalpy of the developed eutectic mixture were found to be 54. 26°C and 157.45 kJ kg⁻¹ respectively. The melting temperature of the eutectic phase‐change material (PCM) fits the drying application. The corrosion analysis test confirms that the prepared eutectic mixture is compact with stainless steel (SS 316) heat exchanger material. Further, the eutectic PCM were characterized using Fourier transform infrared spectroscopy and thermo‐gravimetric analysis, which confirms the material is chemically and thermally stable. The thermal reliability of the eutectic PCM was evaluated through 1000 thermal charge and discharge cycling. In addition, the thermal conductivity of the identified material was found to be 0.18 W m⁻¹ K⁻¹. Thus, the specified material ascertained its suitability for thermal application. Further, 5 kg of eutectic PCM‐filled rectangular heat exchanger was integrated into the solar dryer. The use of eutectic PCM extended the drying time by more than 4 h, which can be helpful to run continuously on intermittent solar days and in the evening after sunset. Hence, the prepared eutectic SA‐B material is irresistible for hot storage dryer application.
... Although, several heat transfer methods have been introduced for electronics, including active and passive cooling. The heat generated inside the miniature and complex circuits of electronic devices can be and chemical stability under repeated charging and discharging modes, higher volumetric density, low super-cooling rate, low vapour pressure, non-toxic, non-flammable, and non-explosive in nature [8]. The rate of energy extraction from a is constrained by the lower thermal conductivity of [9,10]. ...
This work reports the synthesis and characterization of hybrid nanoparticles-based phase change material (HNbPCM) along with a practical approach in the pin-fin heat sink system. In particular, the hybrids of Nickel cobaltite (4 4)-Nickel ferrite (2 4) nanoparticles (−) were synthesized by traditional sol-gel method. The () composites were then prepared by suspending the nanoparticles in paraffin wax () and polyethylene glycol-6000 (− 6000) eutectic organic PCMs with various weight fractions (= 1%-5%). The surface texture, physical and chemical interaction of hybrid nanoparticles and its dispersion in the composites were comprehensively analyzed. The cyclic thermal stability, thermal conductivity, and charging and discharging of characteristics of the developed nano-composites were also confirmed by transient hot-wire apparatus, thermo-gravimetric analysis (), differential scanning calorimetry (). A nanoparticles concentration of 3 wt% in the shows a promising enhancement in the thermophysical properties. The thermal conductivity of was improved by 304.4% by adding hybrid-nanoparticles with = 5%. In addition to thermal conductivity augmentation, nanoparticles enriched altered the phase transition process and eliminated super-cooling by maintaining the high latent heat capacity of 188.95 J∕g in the melting phase and 189.70 J∕g in crystallization phase. A systematic experimental framework of thermal performance characteristics for composite in rectangular pin-fin heat sink subjected to steady state heat transfer for effective and reliable cooling was also studied. The cooling of heat sinks was under testimony at different power inputs, volume fractions and modes of heat transfer in two distinct case studies with and without. A volume fraction of 3 wt% shown the best thermal performance with a heat transfer enhancement up to 3.2 kW∕m 2 with 18 • C temperature reduction in operational time, specific heat capacity, and thermal conducting ability. An improved thermal performance shows considerable thermal and chemical stability, which can expedite the transition process and makes it a desirable prospect for superior thermal energy storage () applications.
... They also have 5-14 times higher volumetric heat capacity compared to sensible storage materials [16]. However, these materials must exhibit certain desirable thermodynamic, kinetic and chemical properties [39]: ...
Modern automotive gasoline engines have highly efficient after-treatment systems that reduce exhaust gas emissions. However, this efficiency greatly depends on the conditions of the exhaust gas, mainly the temperature and air–fuel ratio. The temperature instability during transient conditions may cause a reduction in the efficiency of the three-way catalyst (TWC). By using a thermal energy storage system before TWC, this negative effect can be suppressed. In this paper, the effects of the temperature stabilization on the efficiency of the three-way catalyst were investigated on a 1-D turbocharged gasoline engine model, with a focus on fuel consumption and emissions. The thermal energy storage system (TESS) was based on PCM materials and was built in the exhaust between the turbine and TWC to use the energy of the exhaust gas. Three different materials were picked up as possible mediums in the storage system. Based on the results, the usage of a TESS in a gasoline after-treatment system has shown great potential in improving TWC efficiency. This approach can assist the catalyst to operate under optimal conditions during the drive. In this study, it was found that facilitating the heat transfer between the PCM and the catalyst can significantly improve the emissions’ reduction performance by avoiding the catalyst to light out after the cold start. The TESS with PCM H430 proved to reduce the cumulative CO and HC emissions by 8.2% and 10.6%, respectively, during the drive. Although a TES system increases the after-treatment cost, it can result in emission reductions and fuel consumption over the vehicle’s operating life.
Many times, faster ways of technical developments leave behind certain unanswered questions. Something similar happens with day-by-day growing microelectronic industry. With progression of mankind toward era of digitalization and artificial intelligence, where technology defines the life style of a large section of society, it is very hard for most of us to spend even a day without use of any electronic device. Integrated circuits (ICs) planted in the processing units of these electronic devices generate heat, which is proportional to the power consumed by the device. This generated heat gives rise to the temperature in surroundings of IC and implies adverse effects on IC in form of failure of electron migration, chemical processes, dielectric breakdown, etc. Thus, thermal interface materials (TIMs) play very crucial role in management of dissipated heat. Here, in this review article, the possible ways of removal of this dissipated heat in the electronic devices are outlined. A new technique to improve the functionality of TIMs with the same materials (as researchers earlier tried) but in an effective manner is discussed. We also report an innovative role of free-standing metallic nanostructures in the process of faster and efficient thermal dissipations. The cooling device that we framed is named CV 22 and it can potentially be used to drain the heat produced in electronic devices to sink through a phase change material and metallic nanostructures. The device CV 22 tested in globally known brands like Dell, Lenovo, Acer, Toshiba, HP and Asus, and positive impact on the CPU programming has been obtained. Results shown at the end of this article would frame the CV 22 ahead their available counterparts in the current scenario.
When TIM is used between two mating surfaces, no TIM completely fills the voids of air between them. And thus, being a poor conductor of heat, the presence of air reduces the flow of heat from source and sink, it consequently gives rise to the surroundings temperature. Therefore, the problem of heat conduction still remains there. A new technique to improve the functionality of TIMs with same materials (as researchers earlier tried) but in an effective manner is discussed. We also report an innovative role of free-standing metallic nanostructures in the process of faster and efficient thermal dissipations.
Exploded view of two mating surfaces with practically available TIMs
This paper examines the critical role of effective thermal management in lithium-ion batteries to ensure safety, optimal performance, and extended cycle life. We specifically explore advancements in passive thermal management systems incorporating phase change materials (PCMs) to address the challenges of non-uniform heat generation during high-power operations and rapid charging/discharging. Our study finds that adding aerogel to paraffin improves thermal conductivity by up to 150 %, achieving a value of 0.92 W/m.K. Maintaining battery temperatures within the 15–35 °C range is crucial for optimizing power output and minimizing thermal runaway risks. Our results also show that effective cooling systems can reduce battery capacity decline by 20 % for every 10 °C decrease in temperature, and each degree increase in temperature can reduce battery lifespan by two months. PCM thermal management methods minimize energy consumption and carbon emissions. Sodium phosphate dibasic dodecahydrate reduces carbon monoxide emissions by 28.71 %, and PCM-CNF-Indium reduces energy consumption by up to 31.6 %. Recent studies show that machine learning methods, such as artificial neural networks and genetic algorithms, can enhance the efficiency and reliability of battery thermal management system (BTMS) with PCMs, and the Internet of Things (IoT) is crucial in developing cost-effective, reliable, and sustainable thermal management systems.
Phase change materials (PCMs) have capacity to keep a significant quantity of energy in the form of latent heat when undergoing a phase transition, rendering them very suitable for the management of thermal energy storage. These materials exhibit a diverse array of uses in several facets of our everyday existence, encompassing domains such as logistics, construction, electronics, fabrics and more. The integration of PCMs has also been employed in the advancement of paint and coating formulations, resulting in enhanced thermal energy storage capabilities. To date, the utilization of PCMs in composite materials has demonstrated encouraging outcomes across many applications. An intriguing illustration of these substances involves the integration of PCMs inside paint and coating compositions. There have been many reports of paint and coatings being formulated with the inclusion of PCMs to augment their thermal characteristics. The purpose of this review is to provide the latest advancements in the utilization of paints and coatings integrated with PCMs and evaluate their efficacy as thermal energy storage materials. This review also examines the utilization of PCM in various applications such as coating and paint materials in buildings, solar thermal applications, fabrics and other relevant fields. Special attention will be given to the techniques employed in the preparation of composite PCM coatings and paints.
This study focused on the feasibility of identifying and recycling inorganic phase-change materials (PCMs) from sugar industry wastes in two cities of Qazvin and Hamadan in Iran. In this study, dry sugar beet pomace, sugar beet pomace, sugar beet molasses, leaves and plant residues of sugar beet and sugarcane bagasse were investigated. The inorganic materials were identified by X-ray Diffraction (XRD), thermal characteristics were determined by differential scanning calorimetry (DSC), and morphological characteristics were determined by scanning electron microscopy (SEM). Additionally, physical and thermal properties of molasses and bagasse samples were analyzed to determine their suitability as inorganic PCMs. The results of this study demonstrated that molasses and bagasse have the potential to be used as mineral PCMs in thermal energy storage applications. The results of this study demonstrated that in the wet sugar beet pomace the highest and lowest concentrations of inorganic PCMs were silicon dioxide (SiO2) and sodium chloride (NaCl), respectively. Moreover, the highest calcium fluoride (CaF₂) composition was reported in dry sugar beet pomace. In the samples of leaves and residues of sugar beet and sugarcane bagasse, the highest concentration of was NaCl. The detection and recycling of mineral PCMs from sugar industry wastes offer a sustainable solution for waste management and provide a renewable source of thermal energy storage materials.Implications: This study demonstrated the potential for the extraction of inorganic phase-change materials from sugar industry wastes as a means of solid waste management. By repurposing these materials, we can reduce the environmental impact of sugar production and contribute to sustainable practices in the industry.
Thermal energy harvesting and its applications significantly rely on thermal energy storage (TES) materials. Critical factors include the material’s ability to store and release heat with minimal temperature differences, the range of temperatures covered, and repetitive sensitivity. The short duration of heat storage limits the effectiveness of TES. Phase change materials (PCMs) are a current global research focus due to their desirable thermal properties, which improve energy performance and thermal comfort. PCMs require relatively less synthesis effort while maintaining high efficiency and enhancing cost-effectiveness. However, limited temperature range and storage capacity restrict the application of conventional PCMs. Consequently, the demand for high-energy PCM storage with enhanced thermo-physical properties is high. It is essential to explore the potential of new PCMs to improve thermal storage performance and capacity while reducing energy consumption. This review article explores the classifications and applications of PCMs, addresses the challenges in enhancing their thermo-physical properties, and outlines the selection criteria for high-heat storage applications. Additionally, it provides an in-depth analysis of recent research and developments related to PCMs.
The latent heat storage system is considered the most promising technology in thermal energy storage (TES) because of its many advantages. This technique uses phase change material (PCM) as a TES medium. However, the low thermal conductivity (TC) of PCM is the major drawback of the system. Previous studies have shown that the addition of nanomaterials to PCM generally increases its TC. On the other hand, researchers tend to study the possibility of using enhanced PCM to cool solar cells. In fact, raising the solar cell’s operating temperature negatively impacts its efficiency. This problem is considered one of the biggest problems in solar energy systems, and researchers are still working to solve it. This paper focused on the possibility of enhancing the TC of paraffin by adding different shapes of silver nanomaterials to it (silver nanoparticles, silver nanowires and nanohybrid with silver nanoparticles and silver nanowires). Nanomaterials were added at volume fractions of 0.5% and 1%. Then, the study examined the ability to use this improved material to reduce the temperature of solar cells. We used the “Solidworks” program to create a 3D system, and then we used the “Ansys Fluent” software to simulate five cases; PV without PCM, PV with PCM, PV with PCM enhanced by nanoparticles, PV with PCM enhanced by nanowires, PV with PCM enhanced by nanohybrid (a mixture of nanoparticles and nanowires). The results show that using PCM enhanced by nanowire at a volume fraction of 0.5% gave the best results in decreasing the temperature of PV. The average temperature of PV declined by 14.9[Formula: see text]. In addition, the efficiency of PV rose by about 7.6%. Followed by using PCM enhanced by nanoparticles at a volume fraction of 1%. The average temperature of PV declined by 12.9[Formula: see text]. Moreover, the efficiency of PV rose by about 6.6%.
Layered hybrid organic-inorganic perovskites have gained interest in the scientific community due to their feasibility of being used as phase transition materials to store energy by their polymorphism transitions. These compounds represent excellent candidates for cooling electronic devices, given that approximately 55 % of electronic device failures or damage is attributed to internal overheating. Here, we synthesized (MnCl 4 to evaluate their potential as thermal regulators and to investigate the dependence of their properties on the length of the alkylamine used. The compounds were synthesized by a liquid phase reaction method and the thermal cycling effect was evaluated after 0, 50, 100 and 200 cycles, between 298 K and 333 K. The crystal structure, molecular structure, and thermal properties of the compounds were characterized and compared before and after the thermal cycling. The maximum enthalpy was obtained for the (C 16 H 33 N) 2 CuCl 4 and (C 16 H 33 N) 2 MnCl 4 with 98.1 and 90.5 J⋅g − 1 , respectively. Additionally, all the components were thermally stable up to 200 cycles, with no evidence of structural degradation or thermal properties decreases. Therefore, our results show that these layered hybrid organic-inorganic perovskites could work as effective thermal regulators. By carefully selecting the alkylamine length, it may be possible to optimize their performance further.
As an essential facility for crop growth, the greenhouse creates an indoor microclimate that affects not only the growth quality of vegetation, but also the energy consumption and carbon emission of agriculture. China's agriculture has long been restricted by the traditional nature-dependent mode and lacks an comprehensive theoretical brace for the design and reform of greenhouses. Based on the exothermic and endothermic principle of phase change materials (PCM(s)), this study mainly focuses on the implantation of PCM(s) layers into the envelopes of an actual greenhouse for passive heating. A dynamic simulation of the whole-day indoor temperature self-regulation performance of the greenhouse was performed, and the calculation model was verified. Results show that the embedding of PCM(s) layer in the envelope structure can cut down the high temperature (>30 °C) during daytime and release heat to indoor delayed at night for warming up around 1–2 °C. The north wall is the key component for laying PCM(s), and the critical thickness is the best thermal performance thickness for heating effect. This design solely relies on solar energy with zero carbon emission, and allows for winter passive heating.
Tunable optical devices are of great interest as they offer adjustability to their functions. Temporal optics is a fast-evolving field, which may be useful both for revolutionizing basic research of time-dependent phenomena and for developing full optical devices. With increasing focus on ecological compatibility, bio-friendly alternatives are a key subject matter. Water in its various forms can open up new physical phenomena and unique applications in photonics and modern electronics. Water droplets freezing on cold surfaces are ubiquitous in nature. We propose and demonstrate the effectual generation of time domain self-bending photonic hook (time-PH) beams by using mesoscale freezing water droplet. The PH light bends near the shadow surface of the droplet into large curvature and angles superior to a conventional Airy beam. The key properties of the time-PH (length, curvature, beam waist) can be modified flexibly by changing the positions and curvature of the water-ice interface inside the droplet. Due to the modifying internal structure of freezing water droplets in real time, we showcase the dynamical curvature and trajectory control of the time-PH beams. Compared with the traditional methods, our phase-change-based materials (water and ice) of the mesoscale droplet have advantages of easy fabrication, natural materials, compact structure and low cost. Such PHs may have applications in many fields, including temporal optics and optical switching, microscopy, sensors, materials processing, nonlinear optics, biomedicine, and so on.
Currently, non-renewable resources are heavily consumed, leading to increased global warming resulting from the production of carbon dioxide etc., phase change materials (PCMs) are regarded as a solution to mitigate these global crises attributed to their promising thermal energy storage capability. In this critical review, the thermal properties of different encapsulation methods of PCMs are summarised and compared. Encapsulation ensures that PCMs are used safely and efficiently, therefore the method needs to be thoroughly investigated and improved before their practical implementation. The applicable thermal properties for different encapsulation techniques and encapsulation materials such as particle diameter, enthalpy, encapsulation efficiency and thermal cycling times are reviewed. Future researchers are advised to measure and report thermal conductivities, displaying them in a convenient manner; many studies ignore this parameter, hindering research progression. Evaluation criteria for mechanical properties should be developed to enable comparisons between studies. It is suggested that eutectic and metallic PCMs, sol-gel encapsulation methods, complex coacervation methods, and spray drying are the areas that can be further investigated for better microcapsule performance, higher microcapsule yield, and improved synthesis conditions. In the future, bifunctional microcapsules, copolymer encapsulation, and doped high-performance materials are highly promising developments when compared with current monofunctional capsules with pure polymer shells.
The need to reduce the use of fossil energy, which is running out and harmful to the environment, in response to the increasing energy demand with rapid urbanization, population growth and developing technologies reveals the necessity of research and application of technologies using renewable energy. Phase-change materials (PCM) are one of the most suitable methods for the efficient use of thermal energy originating from clean and sustainable energy sources. PCMs play important roles in a more energy-efficient world. The development of PCMs is one of the most challenging areas of study for more efficient thermal energy storage (TES) systems. This paper first explains the concept of PCMs and then describes the properties of these materials. After mentioned studies for improving the properties of PCMs, then PCM types and advantages-disadvantages are explained. Also, usage areas of PCMs in various sectors are also explained.
Phase change materials (PCMs) have garnered significant attention as low-cost thermal energy storage systems that efficiently capture and store solar energy. Recent review works have largely focused only on thermal conductivity enhancement techniques, and/or applications of PCMs, while others have mainly discussed the performance enhancement of either heating, cooling, or clean energy storage systems integrating with PCMs. However, not enough studies recently reviewed all of these techniques/systems comprehensively to provide insights into them. This paper thus comprehensively reviews the integration of PCMs as an enhancement to most types of heating, cooling, and clean energy storage system performance, and the techniques to enhance thermal conductivity. The integration of PCMs with these systems has shown promising performance. For instance, an improvement of 13.5% is found in the efficiency of photovoltaic (PV) system when it is integrated with PCM/Al2O3 nanoparticles. In addition, the solar air heater's daily energy efficiency reaches 17% on its own, but when combined with PCM, it reaches 33%. However, the major drawback of using PCM–TES (thermal energy storage) for cooling is that PCM does not entirely solidify at night. The literature also shows that the issues related to PCMs' low thermal conductivity, phase separation, and subcooling/supercooling, their poor compatibility with other materials, and the environmental hazards they pose hinder their application on a large scale. It is necessary to implement international standards for assessing the thermophysical properties of PCMs and compile data to better facilitate the utilization of PCMs by end-users.
Phase change energy storage plays an important role in the green, efficient, and sustainable use of energy. Solar energy is stored by phase change materials to realize the time and space displacement of energy. This article reviews the classification of phase change materials and commonly used phase change materials in the direction of energy storage. Commonly used phase change materials in construction and their packaging methods are listed according to the properties of phase change materials. Through different packaging methods to enhance heat exchange, this work solves the problem of material leakage and summarizes the advantages and disadvantages of those methods through comparative analysis. The impact of macro-encapsulation and micro-encapsulation on material encapsulation are also outlined. The simulation and model construction methods of different packaging methods are reviewed. This research is dedicated to the comparative analysis of the selection of phase change materials and packaging methods in buildings a to actively promote the promotion and application of phase change energy storage in buildings.
The high initiating temperature of polymerization up to 80–100 °C during the preparation of solid-solid phase change polymer (SSPCP) leads to the limitation of the embedding procedure during the construction of the battery modules. Herein, we develop a low-temperature preparation strategy for SSPCPs by introducing a redox initiation system to reduce the decomposition activation energy, thus realizing the procedure for embedding the SSPCP into a battery module. In addition to the intrinsic ∼100% anti-leakage performance and ultrahigh heat tolerance up to 250 °C, the SSPCP/expanded graphite composite demonstrates a suitable phase change temperature of 47.8 °C, high thermal conductivity of 2.33 W m⁻¹ K⁻¹, and latent heat of 99.6 J g⁻¹ for battery thermal management, thus delivering a lower maximum temperature (47.4 °C vs. 45.2 °C) for the battery module than traditional composite phase change material during 15 charge-discharge cycles. No leakage traces are detected in the SSPCP module.
Phase change materials (PCMs) are widely used in battery thermal management system (BTMS). Most previous research on BTMS has focused on single temperature environment or protocol, without verifying their effectiveness in volatile working environments, which affects battery heat accumulation and dissipation. In this study, a series of experiments is first conducted to compare the thermal behaviors of battery thermal management modules with different protocols and ambient temperatures to determine the applicability of PCM cooling strategies in different operating conditions. The results show that the constant-current mode produces a smaller temperature fluctuation range but higher temperature, which weakens the effect of PCM cooling and accelerates its failure, especially in high-temperature environments. The PCM cooling technology fails at 1518 s at 54.0 oC in the 45 oC environment with constant current mode while it fails at 2969 s at 44.1 oC in the 35 oC environment. On this basis, we propose a novel PCM cooling structure coupling copper-plate-enhanced heat pipe with PCM to improve secondary heat dissipation, whose cooling performances are compared between forced convection and natural convection. These outcomes can provide a new reference and more insights into diverse application conditions and environments.
For a cleaner environment, the production of fossil fuel propelled transport vehicles need to reduce. Technological advances are aimed to manufacture cost-effective battery electric vehicles compared with the conventional one. An efficient battery cooling system is necessary for safer usage of electric cars during their life cycle. This paper presents two ways of arranging cooling components: liquid filled battery cooling systems (LfBS) and liquid circulated battery cooling systems (LcBS). The air conditioning unit of an electric vehicle has integrated with the battery cooling unit. Cooling performance of LfBS and LcBS arrangements presented for both water and nanofluid as cooling media at 2C and 4C discharge rates. The air required for LfBS cooling or LcBS cooling has supplied at two supply conditions: first, if the ambient temperature is around 35 °C and air-conditioning is ‘OFF’ in an electric vehicle. Second, air-conditioning is ‘ON’ and recirculated air from car cabin is available at 30 °C to supply it to the battery cooling system. The result shows the applicability of such battery systems for the safe operation of electric vehicles.
In a conventional system, the cells of the entire battery pack are sandwiched in a single phase change material
(PCM). The PCM material confining the corner cells may reject heat at a faster rate to the adjoining ambient air
as compared to the cells located in the middle of the pack. In this work, the conventional battery layout system is
modified to induce active and passive cooling for each cell of a battery module. For this, battery pack is arranged
into several modules; each module comprised of six cylindrical cells in a 1S6P arrangement. Each cell is placed in
a 4mm cylindrical gap enclosure filled with phase change material and interconnected together for further
cooling at inter-spacings. Cooling performance of such modified layout is reported at different discharge rates
(2C and 4C) and ambient condition (27 °C, 35 °C and 40 °C). It is found that confined phase change material
around each cell help in better heat dissipation from PCM and improved temperature uniformity in the module.
Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) are clean energy transportation options emerged over traditional internal combustion engine. Li-ion batteries are a viable option for EVs and HEVs due to their advantages of high energy density. At high battery discharging condition, there is a significant increase in battery temperature and non-uniform cell temperature. The cooling performance of battery module at constant current discharge rate about 6.94 C (25 A) have presented. The two side wall of the battery module kept fully open for inflow and outflow of cooling media and better heat dissipation. Larger inter-cell spacing was considered to provide sufficient circulation of cooling air and removal of gases generated by the batteries. The heat generation in the battery cell during discharge process has simulated with the help of user-defined function (UDF). The paper gives insight into a three-dimensional transient thermal response, flow field and thermal regimes developed in the battery module. Different air temperature profiles are confirmed in the flow direction and across the width and depth of the battery pack. At specific zones, the air temperature rises to 7 °C thus indicating the localized heat spots. In the considered BTMS, maximum cell-to-cell temperature non-uniformity is restricted to 0.11 °C and battery temperature is lesser than 28 °C despite the high discharge rate and lower cooling air flow condition.
Using phase change materials (PCMs) for thermal energy storage has always been a hot topic within the research community due to their excellent performance on energy conservation such as energy efficiency in buildings, solar domestic hot water systems, textile industry, biomedical and food agroindustry. Several literatures have reported phase change materials concerning various aspects. Among these materials, salt hydrates are worthy of exploring due to their high-energy storage density, rational price, multiple sources and relatively good thermal conductivity. This paper reviews the present state of salt hydrates PCMs targeting classification, properties, defects, possible solutions as well as their idiographic features which are suitable for applications. In addition, new trends of future research are also indicated.
Thermal energy storage (TES) systems provide several alternatives for efficient energy use and conservation. Phase change materials (PCMs) for TES are materials supplying thermal regulation at particular phase change temperatures by absorbing and emitting the heat of the medium. TES in general and PCMs in particular, have been a main topic in research for the last 30 years, but although the information isquantitatively enormous, it is also spread widely in the literature, and difficult to find. PCMs absorb energy during the heating process as phase change takes place and release energy to the environment in the phase change range during a reverse cooling process. PCMs possesses the ability of latent thermal energy change their state with a certain temperature. PCMs for TES are generally solid-liquid phase change materials and therefore they need encapsulation. TES systems using PCMs as a storage medium offers advantages such as high TES capacity, small unit size and isothermal behaviour during charging and discharging when compared to the sensible TES.
The use of latent heat thermal energy storage for thermally buffering vehicle systems is reviewed. Vehicle systems with transient thermal profiles are classified according to operating temperatures in the range of 0-800degC. Thermal conditions of those applications are examined relative to their impact on thermal buffer requirements, and prior phase change thermal enhancement studies for these applications are discussed. In addition a comprehensive overview of phase change materials covering the relevant operating range is given, including selection criteria and a detailed list of over 700 candidate materials from a number of material classes. Promising material candidates are identified for each vehicle system based on system temperature, specific and volumetric latent heat, and thermal conductivity. Based on the results of previous thermal load leveling efforts, there is the potential for making significant improvements in both emissions reduction and overall energy efficiency by further exploration of PCM thermal buffering on vehicles. Recommendations are made for further material characterization, with focus on the need for improved data for metallic and solid-state phase change materials for high energy density applications.
The use of thermal storage walls that serve both as solar collector and thermal storage is well known. The wall is usually composed of masonry or containers filled with water to provide sensible heat storage, i.e., storage resulting from the specific heat capacity of a material as it increases in temperature. An interesting alternative to the standard materials are phase-change materials (PCMs) which employ latent heat storage. Latent heat storage utilizes the energy associated with a change of state of a material such as the transition from a solid-to-liquid, or liquid-to-gas. The solid-to-liquid phase change is preferred for many applications because of the much smaller volume change resulting in this transition for a given amount of energy storage. This paper summarizes the results of a simulation study of the use of PCMs as a collector-storage wall.
The use of a latent heat storage system using phase change materials (PCMs) is an effective way of storing thermal energy and has the advantages of high-energy storage density and the isothermal nature of the storage process. PCMs have been widely used in latent heat thermal-storage systems for heat pumps, solar engineering, and spacecraft thermal control applications. The uses of PCMs for heating and cooling applications for buildings have been investigated within the past decade. There are large numbers of PCMs that melt and solidify at a wide range of temperatures, making them attractive in a number of applications. This paper also summarizes the investigation and analysis of the available thermal energy storage systems incorporating PCMs for use in different applications.
Concentrated solar power (CSP) is today recognized as a unique renewable energy for electricity generation due to its capability to provide dispatchable electricity incorporating thermal energy storage (TES). Molten salts TES is the most widespread technology in commercial CSP but the industry is looking for cheaper and more efficient TES systems and phase change materials (PCM) have been highlighted as potential low cost and high energy TES systems. This paper presents a completely new concept of PCM energy storage systems to be used in solar thermal electricity plants with its technical assessment. A cascade type PCM storage system is evaluated, using four buckets with the PCM organized based on melting temperature and the latent energy of the materials. Daily, monthly, and annual transient simulations of the plant performance are carried out. The main conclusion is the similarity between this new concept and the commercial two-tank indirect molten salt system. The cumulative power production over the year is similar and the net production of both systems is well matched.
Advances in thermal energy storage techniques/methods, using Phase Change Material (PCM), have gained much hype among researchers in the last decade. Thermal energy storage systems can significantly reduce energy consumption and promotes the use of renewable sources of energy. In recent decades , the building sector has evolved as one of the major consumer of energy resulting in high levels of carbon emissions. Thermal energy storage combined with PCM is an effective method for improving the energy efficiency of the buildings. PCM can be incorporated in the building envelope in many ways. One of the simplest and effective method of integrating PCM directly in building material is macroencapsula-tion. This method not only improves the indoor thermal behavior of the buildings, but also reduces the cooling load without or little compromising with the mechanical strength of the building structure. In this article, a critical review of the application of macroencapsulated PCM in buildings for energy savings has been carried out. A detailed review of various approaches to integrate the macroencapsulated PCM in the building envelope has been shown. Effect on indoor thermal behavior and reduction in cooling load was analyzed for different approaches. Additionally, the compatibility of various materials used for making containers for encapsulation was also investigated. A detailed description of macroencapsulation technique, types of thermal energy storage methods used in buildings, suitable PCM available for encap-sulation has also been shown in the article.
Present study deals with melting and solidification of PCM inside cylindrical container with different shapes of shell and also different arrangements of inner tubes. Nine different cases with identical amount of PCM are considered for the investigation. The inner tubes are of constant temperature and the shell in all cases is adiabatic. Results show that conduction is the dominant mechanism at earlier time. Later, natural convection has significant effect on the melting process where PCM at the upper half of container is melted while a large amount of it is still solid at the lower half. Case with two tubes in vertical array and case with one tube have the highest and lowest melting rate, respectively. Longest and shortest solidification time respectively belongs to the case with two tubes located along x direction and case with four tubes in diamond array. Following to this, copper foam is inserted inside PCM to enhance the phase change rate which is solved by non-equilibrium thermal condition between metal foam and PCM. Results indicate that the temperature of metal foam ligament changes much faster than PCM. Moreover, inserting metal foam increases the melting and solidification rates up to 92% and 94%, respectively. However, it suppresses the natural convection especially in melting process.
Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) are clean energy vehicles in comparison with a traditional internal combustion engine. Li-ion batteries are a viable option for EVs and HEVs due to their advantages of high specific energy and energy density. At high discharge rate, there is a significant increase in battery temperature and non-uniform cell temperature. This work presents a numerical study of the transient behavior of a novel confined flow battery module dissipating the heat at very high discharge rate around 6.94 C and 11.11 C. The conventional open flow battery modules are modified considering the controlled/ guided flow stream around the cell for reducing the local heat spots and unevenness in the cell temperatures. The results provide insights and comparisons into a cell-to-cell heat interaction based on three-dimensional transient thermal response and thermal regimes developed in a conventional open flow module and confined flow module. During battery discharging condition, the proposed battery module exhibit lower surface temperature as well as near uniform cell temperature as compared to open flow module.
In this paper, a novel solar water heating system (SWHS), capable of reducing the impact of solar radiation intensity fluctuations, has been fabricated by using phase change materials (PCM) for thermal energy storage and inserted oscillating heat pipe (OHP) for performance improvement. Different working modes can be selected according to the solar radiation intensity in different seasons and different climate conditions. A test rig has also been made for the performance measurement of the system. The full-year measurement in all kinds of environmental conditions has been carried out for a couple of consecutive years, in Nanjing city of China. The system performances, such as collecting efficiency (CE), average collecting efficiency (ACE), coefficient of performance (COP) and exit water temperature (EWT), have been measured and compared between the systems with and without PCM. Under similar operation conditions, the system with PCM is illustrated to have much better performances. In daytime, CE fluctuation with PCM is over 30% less than that without PCM. At summer night, EWT with PCM can keep over 50 °C, while EWT without PCM has an obvious decrease. At winter night, COP with PCM is over 3.0 that can make EWT reach to 50 °C in a much shorter time than that without PCM. The system presented is proved to be effective and useful in the application of solar energy.
The success of improved fuel economy is the proper integration of thermal management components which are appropriately performed to reduce friction and wasted energy. The thermal management systems of vehicle are able to balance the multiple needs such as heating, cooling, or appropriate operation within specified temperature ranges of propulsion systems. Since the propulsion systems of vehicle have changed from a single energy source based on conventional internal combustion engine to hybrid system including more electrical system such as full type of hybrid electric vehicle or plug-in hybrid electric vehicles, a new transition associated with vehicle thermal management arises. More efficient thermal management systems are required to improve the fuel economy in the hybrid electric vehicles because of the driving of electric traction motor and the increase of engine off time. The decrease of engine operation time may not sustain the proper temperature ranges of engine and gearbox. As an engine starts at low ambient temperature, heat from the wasted heat of exhausted gas can be supplied not only to cabin heater, but also to engine and gearbox at initial warm-up. To practically apply recent thermal management technologies in commercial use, improved performance for the low energy density per cost in a viable vehicle package is necessary in general. This research describes the one of cost effective thermal management solutions recovering exhaust gas heat exchanging system with coolant and gear box oil simultaneously. The previous type of recovering the exhaust heat is to exchange the heat between the coolant and the exhaust gas to increase the temperature of the engine coolant, thereby reducing the friction and improving the fuel efficiency. However, the reduction in engine friction loss and improvement of fuel economy remains low due to the short period of exchanging heat between exhaust gas and coolant. It is more advantageous to increase the temperature of the engine oil or gear box oil rather than to increase the coolant temperature. Accordingly, the developed exhaust heat recovery device which performs integral heat exchange of the exhaust gas heat of engine increases the temperature of the coolant and the gear box oil, thereby reducing friction loss and improving fuel economy. The experimental result of this system improved 2.5% of fuel economy at UDDS drive cycles.
Currently, in the typical internal combustion engine, approximately one third of fossil fuel combustion by-product is wasted heat. In the continued effort to improve fuel economy, one area that is being researched today is the harvesting of wasted energy to increase vehicle efficiency. This paper will address how heat emitted by exhaust systems can be captured and used to increase vehicle efficiency. Overall we will compare energy content in the exhaust manifold and exhaust underfloor mid-vehicle position, where potential exhaust heat exchanger concepts can reside. These heat exchanger concepts are designed primarily to capture heat from these locations and transfer the energy for increased passenger heating and comfort during cold conditions and/or supplement other improvements in power train efficiencies. An analysis of the energy exchange to the heated fluid is compared in the exhaust manifold and underfloor position respectively. Issues associated with heat energy harvesting from a typical exhaust system will be presented in detail, with suggestions for improving future systems. The innovation behind the Faurecia Exhaust Heat Recovery System (EHRS) performance will be presented in detail for exhaust underfloor installation. Rather than throw off the heat emitted by exhaust systems, this innovation uses a gas/water heat exchanger to supplement the heating up the engine coolant. As a result, exhaust heat helps the vehicle interior to warm up in 25 percent less time than with conventional systems. This process can provide a shorter heating time for the powertrain as well. When the powertrain temperature increases more rapidly after start-up, fuel consumption improves. Adaptation of this technology is also under development to boost the fuel savings of hybrid vehicles by increasing the duration of all-electric driving in the winter. More rapid warming decreases power demand and enables vehicles to travel farther on their electric motors. This system offers the potential of an 8 to 10 percent improvement in fuel economy for hybrid vehicles, with an environmentally friendly solution that replaces auxiliary heating systems.
This paper investigates heat transfer with phase change materials (PCMs) in passive thermal management of electric and hybrid electric vehicles where the PCM is integrated with a Li-ion cell. When higher current is extracted from the Li-ion cells, heat is generated due to the ohmic law. Therefore, it is vital to design a successful thermal management system (TMS) to prevent excessive temperature increase and temperature excursion in the battery pack. During the phase change process, PCMs absorb heat and create a cooling effect. In the discharging (solidification) process, stored heat is released and it creates a heating effect. The case considered in this paper includes the use of PCMs with different thicknesses around the cells. Despite the small peripheral surface of the prismatic cell, the orthotropic property of Li-ion cells improves the planar heat transfer and effectiveness of the PCM around the cell. A numerical study is conducted using a finite volume-based method. The results show that the maximum temperature and temperature excursion in the cell are reduced when PCM is employed. The PCM with 12 mm thickness decreases the temperature by 3.0 K. The corresponding value for thinner layers of 3 mm, 6 mm and 9 mm are then obtained as 2.8 K, 2.9 K and 3.0 K respectively. Furthermore, the effect of the PCM on the cell temperature is more pronounced when the cooling system is under transient conditions. When a 3 mm-thick PCM is employed for the Li-ion cell, the temperature distribution becomes about 10% more uniform which is an important result in thermal management systems in electric vehicles.
This paper presents the results of a numerical and experimental study on thermally efficient windows. Experimental investigation using spectrophotometry was realized on simple and composite glass samples filled with air or phase change material. The transmittance and reflectance tests indicated large reduction in the infrared and ultraviolet radiations while maintaining good visibility. The number of glass sheets, their thickness and the gap between them were also investigated. The numerical model is based upon one-dimensional formulation of the composite window. The program was optimized and the predicted results are presented and discussed.
Thermal energy storage with phase change materials (PCMs) offers a high thermal storage density with a moderate temperature variation, and has attracted growing attention due to its important role in achieving energy conservation in buildings with thermal comfort. Various methods have been investigated by previous researchers to incorporate PCMs into the building structures, and it has been found that with the help of PCMs the indoor temperature fluctuations can be reduced significantly whilst maintaining desirable thermal comfort. This paper summarises previous works on latent thermal energy storage in building applications, covering PCMs, the impregnation methods, current building applications and their thermal performance analyses, as well as numerical simulation of buildings with PCMs. Over 100 references are included in this paper.
The possibility of cooking during off-sunshine hours using phase change materials (PCMs) as storage media has been investigated experimentally. For this purpose, two concentric cylindrical vessels were constructed with 2-cm gaps. This gap was filled with stearic acid or magnesium nitrate hexahydrate as the PCMs. The cooker performance is evaluated in terms of charging and discharging times of the PCMs under different conditions. The cooker performance was found to depend strongly on the solar intensity, mass of the cooking medium, and the thermophysical properties of the PCM. The overall efficiency of the cooker during discharging was found to be 3–4 times greater than that for steam and heat-pipe solar cookers, which can be used for indoor cooking.
A novel thermal‐management system that incorporates phase‐change material (PCM) is proposed and investigated for electric
vehicle (EV) applications. A commercial finite‐element (FE) software, PDEase2D™, was used to simulate the thermal behavior
of EV battery modules with a PCM thermal management system. Simulation results show that the temperature profile of the cells
integrated in the module design was substantially more uniform during discharge at different rates than without PCM. The PCM
system is effective in thermally sensitive batteries such as Li‐ion and most Li‐polymer batteries with a significant reversible
heat effect. The heat generated during discharge and stored as latent heat is then largely utilized during charge, and a smaller
part of it is transferred to the surroundings. The stored heat will be rejected to the module when the battery is left to
relax or when its temperature drops below the melting point of the PCM. This is an important advantage for EV operation under
cold conditions or in space applications where the battery temperature drops significantly when an orbiting satellite moves
from the light to the dark side of the earth. © 2000 The Electrochemical Society. All rights reserved.
In this paper, a phase change material (PCM) storage unit for a solar cooker was designed and developed to store energy during sunshine hours. The stored energy was utilised to cook food in the late evening. Commercial grade acetanilide (melting point 118.9 °C, latent heat of fusion 222 kJ/kg) was used as a latent heat storage material. Evening cooking experiments were conducted with different loads and loading times during the winter season. The experimental results showed that late evening cooking is possible in a solar cooker having three reflectors to enhance the incident solar radiation with the PCM storage unit.
Thermal energy storage is one of the most efficient ways to store solar energy for heating air by energy collected from sun. The relative studies are involved to the type of collection with the type of storage, i.e. separated to each other or integrated. This review summarizes the previous works on solar air heaters with storage materials include greenhouse, encapsulation, and the latest development in the solar thermal energy storage with air as a heat transfer fluid. The recent researches focused on the phase change materials (PCMs), as latent heat storage is more efficient than sensible heat storage. It has been appeared that PCM with high latent heat and suitable geometry are required for optimum thermal performance of solar air heater. The recent designs of solar air heaters with thermal storage units reduced the cost and the volume when integrated in one product.
A major obstacle to the development of commercially successful electric vehicles (EV) or hybrid electric vehicles (HEV) is the lack of a suitably sized battery. Lithium ion batteries are viewed as the solution if only they could be “scaled-up safely”, i.e. if thermal management problems could be overcome so the batteries could be designed and manufactured in much larger sizes than the commercially available near-2-Ah cells.Here, we review a novel thermal management system using phase-change material (PCM). A prototype of this PCM-based system is presently being manufactured. A PCM-based system has never been tested before with lithium-ion (Li-ion) batteries and battery packs, although its mode of operation is exceptionally well suited for the cell chemistry of the most common commercially available Li-ion batteries. The thermal management system described here is intended specifically for EV/HEV applications. It has a high potential for providing effective thermal management without introducing moving components. Thereby, the performance of EV/HEV batteries may be improved without complicating the system design and incurring major additional cost, as is the case with “active” cooling systems requiring air or liquid circulation.
A wallboard new PCM material is experimentally investigated in this paper to enhance the thermal behavior of light weight building internal partition wall. The experiments are carried out in a full-scale test room which is completely controlled. The external temperature and radiative flux dynamically simulate a summer repetitive day. The differential test concern walls with and without PCM material under the same conditions. The PCM allows to reduce the room air temperature fluctuations, in particular when overheating occurs. A numerical modeling has been used to investigate energy storage. Five millimeters of PCM wallboard double the energy that can be stocked, and destocked, during the experiment. The experiments are fully described so that the results can be used for the validation of numerical models dealing with phase change materials.
Increasing interest is being shown in the use of organic phase change materials (PCMs) in concrete building materials for heat storage. This had led to studies in means of improving their thermal performance. A principal factor in the effective use of PCM concrete is the amount of PCM which can be absorbed. This study examines the mechanisms of absorption and establishes a means of developing and using absorption constants for PCM concrete to achieve diffusion of the desired amount of organic PCM and hence the required thermal storage capacity. The effects of temperature. PCM viscosity, concrete density and hydrogen bonding on PCM penetration were demonstrated. Void fractions in the concrete and the manner in which they were filled with PCM was also observed.
Simulation techniques are used to examine the performance of air-based solar heating systems utilizing phase change energy storage (PCES). The effects of storage size, melting temperature, and latent heat on the thermal performance of the system are quantified for various load characteristics, collector types, and control strategies. The effect of semi-congruent melting of the phase-change material (PCM) on system performance is also examined. Based on these simulations, 1.(1) optimum physical properties of the PCM have been identified,2.(2) an empirical method for sizing PCES units has been developed,3.(3) a system-oriented figure of merit for comparing different PCMs has been established, and4.(4) the economic gains associated with the storage volume reductions achieved with PCES, vis-à-vis sensible heat storage in rock beds, have been quantified.
Efficient and economical technology that can be used to store large amounts of heat or cold in a definite volume is the subject of research for a long time. Thermal storage plays an important role in building energy conservation, which is greatly assisted by the incorporation of latent heat storage (LHS) in building products. LHS in a phase change material (PCM) is very attractive because of its high storage density with small temperature swing. It has been demonstrated that for the development of a latent heat storage system (LHTS) in a building fabric, the choice of the PCM plays an important role in addition to heat transfer mechanism in the PCM. Thermal energy storage in the walls, ceiling and floor of buildings may be enhanced by encapsulating or embedding suitable PCMs within these surfaces. They can either capture solar energy directly or thermal energy through natural convection. Increasing the thermal storage capacity of a building can increase human comfort by decreasing the frequency of internal air temperature swings so that the indoor air temperature is closer to the desired temperature for a longer period of time. This paper aims to gather the information from the earlier works on the developments of PCM's incorporation in building, the problems associated with the selection of PCM and the various methods used to contain them for space heating and cooling applications.
A review on pure fatty acid based phase change materials for energy storage applications
- Sharma
Eutectic mixture of capric acid and myristic acid as phase change materials
- Jilte