•PCM can regulate the pavement temperature by releasing or absorbing heat.•The leaked PCM will chemically react with asphalt and effect its performance.•PCM can improve high-temperature stability and ...crack resistance of asphalt mixture.•The synthesis process of CPCM still needs to be explored to reduce PCM losses.
Phase change materials (PCMs) can adjust the external temperature by changing their phase states. In order to understand the application of PCMs in asphalt pavements, this paper mainly studied the classification, mechanism, thermoregulation effects of PCMs and the preparation method of composite phase change materials (CPCMs). In addition, the effects of directly incorporated PCMs and composite ones on the properties of asphalt binder and asphalt mixture were described. Results show that directly incorporated PCMs play a role in thermoregulation. However, there is high temperature leakage phenomenon, which has a significant adverse effect on the road performance of asphalt binder and asphalt mixture. CPCMs effectively prevented leakage, reduced the adverse impact on the physical properties of asphalt binder. It is an ideal way to add CPCMs as an alternative component to asphalt mixture. CPCMs improved the heat storage and release capacity of asphalt mixture and the road performance of asphalt mixture, such as high-temperature stability, low-temperature anti-cracking had been improved.
The production of alternative clean energy vehicles provides a sustainable solution to the transportation sector. An efficient battery cooling system is necessary for safer usage of electric cars ...during their life cycle. The current work presents a novel modified battery module configuration employing two-layer nanoparticle enhanced phase change materials (nePCM). The design suggests m × n × p arrangement where m denotes the number of Li-ion 18,650 cells, n and p refer to the number of primary containers (filled with nePCM1) and secondary containers (filled with nePCM2). Each Li-ion cell was allowed to discharge at 3C condition for two different configurations: 7 × 7 × 1 and 7 × 1 × 1. The study involves a cooling performance comparison of proposed battery thermal management systems (BTMS) at an ambient temperature ranging from 30 °C to 40 °C with external natural convection conditions. The transient development of heat in batteries and the melting behavior of nePCMs shows better cooling performance for the 7 × 7 × 1 case. BTMS based on 7 × 7 × 1 configuration maintains the cell temperature below 46 °C with combined nePCM and external natural convection cooling even at the hot ambient temperature of 40 °C.
Thermal energy storage (TES) systems using phase change material (PCM) have been recognized as one of the most advanced energy technologies in enhancing the energy efficiency and sustainability of ...buildings. Now the research is focus on suitable method to incorporate PCMs with building. There are several methods to use phase change materials (PCMs) in thermal energy storage (TES) for different applications. Microencapsulation is one of the well known and advanced technologies for better utilization of PCMs with building parts, such as, wall, roof and floor besides, within the building materials. Phase change materials based microencapsulation for latent heat thermal storage (LHTS) systems for building application offers a challenging option to be employed as effective thermal energy storage and a retrieval device. Since the particular interest in using microencapsulation PCMs for concrete and wall/wallboards, the specific research efforts on both subjects are reviewed separately. This paper presents an overview of the previous research work on microencapsulation technology for thermal energy storage incorporating the phase change materials (PCMs) in the building applications, along with few useful conclusive remarks concluded from the available literature.
In recent years, researchers are fascinated to counter problem of PV-efficiency decline arising from high operating temperatures, especially in hot climates. This article conducts a comprehensive ...review of research activities performed in last 5 years, on cooling techniques with phase-change materials (PCMs), nanofluids and their combined use, leading to efficiency enhancement. By passive cooling approach with PCMs, it is found that maximum enhancement up to 20% in PV-efficiency can be achieved. Effectiveness of PCM for PV is more prominent in summer than in winter. Incorporations of fins inside PCM container at PV rear, results in much improved heat conduction within PCM. Now-a-days, researchers have grown interest in composite PCMs for PV cooling due to their enhanced thermal conductivity. Moreover, better heat regulation as well as PV-surface temperature uniformity can be achieved with two PCMs at a time having different melting points. Studies suggest that combination of passive & active cooling techniques helps in further lowering of PV-cell temperature, leading to enhancement in PV-efficiency with additional thermal power generation. PV-efficiency of water-based hybrid PV/T systems can be improved by 32% by integration with PCM. Although nanofluid-based PV/T systems have been proved to enhance PV-efficiency by more than 60%, but combined use of PCM & nanofluid is more effective approach for PV cooling than individual use of PCM or nanofluid. If combination is made between nanofluid & nano-PCM, electrical power & efficiency can further be enhanced. Nanofluids can also be considered a good spectral filter alternative as they require small thickness and are able to be tuned by varying nanoparticles conc. Finally, environmental impacts & economic viability of mentioned cooling techniques, were discussed. Studies show that PV/PCM systems become expensive & less feasible when operated in single junction due to long payback period up to 20 years. Economic feasibility can be increased by combining passive & active cooling techniques which can increase system compactness and lower its cost.
Phase‐change materials (PCMs) are seeing tremendous interest for their use in reconfigurable photonic devices; however, the most common PCMs exhibit a large absorption loss in one or both states. ...Here, Sb2S3 and Sb2Se3 are demonstrated as a class of low loss, reversible alternatives to the standard commercially available chalcogenide PCMs. A contrast of refractive index of Δn = 0.60 for Sb2S3 and Δn = 0.77 for Sb2Se3 is reported, while maintaining very low losses (k < 10−5) in the telecommunications C‐band at 1550 nm. With a stronger absorption in the visible spectrum, Sb2Se3 allows for reversible optical switching using conventional visible wavelength lasers. Here, a stable switching endurance of better than 4000 cycles is demonstrated. To deal with the essentially zero intrinsic absorption losses, a new figure of merit (FOM) is introduced taking into account the measured waveguide losses when integrating these materials onto a standard silicon photonics platform. The FOM of 29 rad phase shift per dB of loss for Sb2Se3 outperforms Ge2Sb2Te5 by two orders of magnitude and paves the way for on‐chip programmable phase control. These truly low‐loss switchable materials open up new directions in programmable integrated photonic circuits, switchable metasurfaces, and nanophotonic devices.
New optical phase‐change materials are demonstrated, with the ability to realize on‐chip programmable phase control with very low optical losses. The chalcogenides Sb2S3 and Sb2Se3 exhibit a large refractive index contrast between their crystalline and amorphous phases. With reversible switching over thousands of cycles and easy integration with silicon, these materials pave the way for low‐loss reconfigurable and programmable nanophotonics.
•A novel Coupled PCM-liquid cooling system (CPLS) for Li-ion battery pack.•Design of CPLS is optimized for the thermal performance of battery pack.•Effectiveness of CPLS is verified by the designed ...experiments.•Controlling strategy for the velocity and inlet temperature of coolant.•Improved cooling performance and energy-saving at different ambient temperatures.
In order to improve the working performance of the lithium-ion battery pack in continuous operation under different ambient temperatures, a coupled composite phase change material and liquid cooling thermal management system is proposed. The simulation for this system under a cycle that a 3C rate discharging and then a 0.5C charging was conducted, as well as comparison tests concerning factors such as cell-to-cell spacing, cell-to-tube distance, channel number and coolant velocity. Simulation results showed that the coupled system with suitable design exhibited good thermal performance at an ambient temperature of 30 °C, which kept the maximum surface temperature and the temperature difference of the battery pack at 41.1 °C and 4 °C at the end of 3C discharge. Then, the latent heat of phase change material was also recovered by the liquid cooling during the 0.5C charge. Specially designed experiments have also been conducted to verify the effectiveness and practicability of the proposed coupled system. Based on this system, a liquid cooling strategy was proposed for controlling the velocity and inlet temperature of coolant by monitoring the temperature of the phase change material and environment. This further improved the thermal performance of the battery pack during cycling at different ambient temperatures and significantly reduced the unnecessary power consumption of liquid cooling during this process.
The development of energy saving technologies is very actual issue of present day. One of perspective directions in developing these technologies is the thermal energy storage in various industry ...branches. The review considers the modern state of art in investigations and developments of high-temperature phase change materials perspective for storage thermal and a solar energy in the range of temperatures from 120 to 1000
°C. The considerable quantity of mixes and compositions on the basis of fluorides, chlorides, hydroxides, nitrates, carbonates, vanadates, molybdates and other salts, and also metal alloys is given. Thermophysical properties of potential heat storage salt compositions and metal alloys are presented. Compatibility of heat storage materials (HSM) and constructional materials have found its reflection in the present work. Data on long-term characteristics of some HSMs in the course of repeated cycles of fusion and solidification are analyzed. Article considers also other problems which should be solved for creation of commercial high-temperature heat storage devices with use of phase change materials.
•A novel liquid cooling plate embedded with PCM for battery thermal management.•The cooling plate provides a modular solution for battery cooling with PCM.•The cooling plate is 36% lighter than an ...aluminum cooling plate of the same size.•Up to 30% reduction in pump energy consumption is achieved by the new cooling plate.•The cooling plate provides a heating solution for batteries in cold temperatures.
In this paper, an innovative liquid cooling plate (LCP) embedded with phase change material (PCM) is designed for electric vehicle (EV) battery thermal management. The proposed cooling plate is named “hybrid cooling plate” as it takes advantage of both active (liquid) and passive (PCM) cooling methods. The hybrid LCP is 36% lighter than a volumetrically equivalent traditional aluminum LCP, and in addition to the cooling capability, it provides a heating solution to slow the temperature loss of the batteries during the cold stop. The thermal behavior of the hybrid LCP for two different scenarios including the cooling performance under a real driving cycle, and the cold stop temperature performance are investigated and compared with a traditional aluminum LCP using a computational fluid dynamics (CFD) model. An experimental test bench is developed to test a prototype of the hybrid LCP and verify the CFD model. The cooling performance results indicate that the use of hybrid LCP could reduce the energy consumption of the pump required for circulating the coolant up to 30% in comparison with an aluminum LCP. Moreover, the novel designed LCP improves the temperature uniformity effectively. It was also found that the hybrid LCP could significantly delay the temperature drop at the cold stop situation of the EV and therefore, reduce the energy needed for the active heating of the batteries after short-term parking. These imply that the hybrid liquid cooling plate concept could be a promising thermal management solution for EVs.
Phase change materials (PCMs) have received attention for various applications in solar heating systems, building energy conservation and air-conditioning systems. However, they need encapsulation in ...order to prevent leakage of the melted PCM during the phase change process. Now, these problems can be solved by using shape-stabilized PCMs. These shape-stabilized PCMs can be prepared by integrating the PCMs into the supporting material and microencapsulating the PCMs into the shell. This paper presents a review on preparation, thermal properties and applications of shape-stabilized thermal energy storage materials. The thermal properties of the composite phase change material and microencapsulated phase change material are analyzed and discussed. The applications of shape-stabilized thermal energy storage materials are summarized.
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