Phase Change Material Components Research Articles

Development and optimization of hybrid heat dissipation system for lithium-ion battery packs

This study presents the development and optimization of an advanced hybrid heat dissipation system for lithium-ion battery packs designed explicitly for drone applications. The system employs a novel battery capsule filled with a phase change material (PCM) compound enhanced with 2 % Huber nano-carbon, demonstrating superior thermal conductivity and stability. The capsules were manufactured using 3D printing technology, with paraffin wax and carbon black powders as the PCM components. Thermal simulations and experimental results indicated that the oval-shaped capsules with a major/minor axis ratio of 17.2/14.2 mm provided the most effective heat dissipation, maintaining the battery within a safe operating temperature range. Comparative studies revealed that the PCM-filled capsules outperformed the efficiency of air-filled and pure paraffin wax-filled capsules in thermal management. The system’s dual approach, combining passive PCM cooling with active air cooling, significantly extended the battery’s operational life and safety by ensuring optimal temperature regulation. This research highlights the potential for integrating nano-carbon-enhanced PCMs in high-performance, temperature-sensitive devices, paving the way for broader applications in electric vehicles, portable electronics, and advanced energy storage systems.

Compatibility of PCM modified asphalt based on naphthenic oil modification: A multiscale study

In this study, the compatibility of phase change material(PCM) in asphalt was investigated using several methods. Initially, solubility parameters, radial distribution functions, and relative concentrations of PCM modified asphalt were examined through molecular simulations to explore its compatibility. Subsequently, the phase structures of different PCM modified asphalt were analyzed using fluorescence microscopy experiments on both upper and lower samples. Finally, the compatibility differences among PCM modified asphalt samples with varying naphthenic oil contents were evaluated through softening point and Brookfield viscosity tests. The results indicate that higher naphthenic oil content in encapsulated PCM leads to closer solubility parameter alignment with the base asphalt. At a naphthenic oil content of 50% in encapsulated PCM, significant interactions occur between PCM and asphalt components. The concentration distribution curve of PCM molecules in the asphalt approaches 1.0, indicating excellent compatibility between encapsulated PCM and asphalt. Overall, the results from fluorescence microscopy and conventional tests are consistent with simulation outcomes. The only discrepancy observed is that conventional experimental results for the PCM-60% sample slightly outperform those for the PCM-50% sample.

Phase change material window for dynamic energy flow regulation: Review

The phase change material (PCM) window is a promising technology for enhancing the thermal regulation capabilities of transparent facades by dynamically regulating the energy flow between indoor and outdoor environments. By storing and releasing thermal energy during phase transitions, PCM windows can effectively regulate indoor temperature and reduce heating or cooling loads. This study examines 53 research studies published within the last decade. These studies are analyzed based on geographic distribution, PCM material types, research methods, and performance indices. The PCM windows are categorized according to the PCMs integration measures, which include direct infill to the window cavity, embedding within window frames, and integration with built-in heat exchangers to preheat or precool the vent air. The light, thermal, and energy performances of these innovative PCM windows are summarized and discussed. Moreover, the potential of dynamic designs for PCM windows to enhance the light and thermal regulation abilities through flexible arrangement of PCM components is recognized as promising. However, a comprehensive assessment of their performance and energy-saving potential still need to be fully explored. This review identifies potential challenges and limitations associated with PCM window studies and applications, highlighting the need for future investigation to fully explore the benefits of dynamic designs and renewable energy utilization. These findings provide valuable insights for researchers and practitioners seeking to optimize the use of PCM windows in building envelopes.

Research on the thermal performance of interlayer ventilated PCM component coupled with solar air collector

The application of solar energy for heating in buildings has the problem of heat supply and demand time mismatch. In this paper, an interlayer ventilated phase change material (PCM) component (IVPC) that can be coupled with solar air collector was proposed. The thermal performance of IVPC was tested through experiments. The results show that if IVPC completes latent heat storage, the optimal air supply temperature of solar hot air is 35 ∼ 45℃ and the air supply speed is 3 ∼ 4 m/s. The latent heat release time can be maintained for 5 h. To build an IVPC coupled with solar air collector system (IVPSS) in TRNSYS, to simulate the improvement effect of IVPC on heating temperature fluctuations, a rural building in cold regions of China was selected. IVPSS can maintain the indoor temperature of the building in the range of 8 ∼ 16℃. Compared with buildings without IVPSS, the room temperature throughout the day can be increased by 5 ∼ 8℃. IVPC can effectively use solar energy to peak load shifting, reduce room temperature fluctuations, improve indoor thermal comfort, and provide solutions for farmhouses in cold regions to use clean energy for heating.

Numerical analysis of influencing factors on heat storage time of phase change material in an inclination rectangular cavity based on orthogonal method

In this paper, factors affecting the completely melting time of phase change material (PCM) in a rectangular cavity are analyzed. The influence of three factors including inclination angle of the cavity, heating temperature, and geometry of the cavity on completely melting time is discussed under the boundary condition of single size heating and double sizes heating respectively, while other sides are considered to be adiabatic. A two-dimensional mathematical model is established for the simulation analysis and verified by experiments. In order to analyze the influence of all factors on the completely melting time, the orthogonal analysis method is adopted, and the range analysis method is used to determine the influence of three factors on the completely melting time. Based on the orthogonal analysis, it can be found that the heating temperature is the most significant factor during single side heating, while geometry of the cavity is the most important factor during double sides heating. The results will be helpful to optimize the structure of PCM component used for energy storage system or temperature control structure.

Optimization of phase change material component and its application in buildings

Improving the thermal transfer performance of phase change material (PCM) component has attracted more and more attention in building the energy-saving field. This paper presented an optimized PCM component which is encapsulated in a metal container, to promote the thermal performance of the wall. Thermal transfer of PCM component is optimized by adding internal fin through numerical simulation software COMSOL Multiphsics. The simulation model was verified by data from publicly available published literature. The temperature difference of PCM component in front and back heating surface (ΔTs) was employed to obtain the optimal geometric parameters including spacing (Sfin) and length (Lfin) of the fin. Thermal performance of the wall with the optimized and non-optimized PCM component was compared under the summer typical climate. The wall with optimized PCM component has the best capacity for heat storage and release. The interior surface temperature reduction of the wall with optimized PCM component is lower by 2.1 ºC than reference wall.

Enhancing a vertical earth-to-air heat exchanger system using tubular phase change material

Abstract: In this study, a new vertical earth-to-air heat exchanger (VEAHE) system coupled with tubular phase change material (PCM) components was proposed. The proposed system has smaller occupied areas and higher geothermal energy use efficiency than traditional EAHE systems. Moreover, the tubular PCM component enables the system's air temperature at the outlet to be more stable, thereby enhancing the system's thermal performance. In particular, the tubular components' simple geometry, easy fabrication, convenient assembling-disassembling and low-cost facilitate their usage in practical applications. To explore the system's thermal performance, an experimental set-up was established and its numerical model was developed. Then the model was verified through a comparison between the system's simulated and monitored air temperatures at the outlet. The verification produced acceptable results with the maximum absolute relative error of 1.33%. Based on this model, the influences of the tubular PCM component, tube depth, PCM conductivity and container length on the proposed system's thermal performance were investigated. Results indicated that the tubular PCM components can effectively reduce the VEAHE system's air temperature peak and fluctuation at the outlet, and increase its average cooling capacity. For the proposed system, as the tube depths increase from 12 to 24 m, the air temperature peak and fluctuation at the outlet decrease from 25.74 °C and 3.59 °C to 21.01 °C and 0.62 °C, respectively. Different thermal conductivity of PCM has almost same influences on the system's air temperature at the outlet as the container diameter is 50 mm. Such influences, however, become apparent and require to be considered as the container diameter increases to 150 mm. The air temperature fluctuation at the outlet decreases as the container lengths increase, and 12 m can be considered as an appropriate length for the proposed system. Additionally, the system's static payback period was calculated as 18.03 years.

Analysis and Design of a Paraffin/Graphite Composite PCM Integrated in a Thermal Storage Unit

The addition of latent heat storage systems in solar thermal applications has several benefits including volume reduction in storage tanks and maintaining the temperature range of the thermal storage. A phase change material (PCM) provides high energy storage density at a constant temperature corresponding to its phase transition temperature. In this paper, a high temperature PCM (melting temperature of 80°C) made of a composite of paraffin and graphite was tested to determine its thermal properties. Tests were conducted with a differential scanning calorimeter and allowed the determination of the melting and solidification characteristics, latent heat, specific heat at melting and solidification, and thermal conductivity of the composite. The results of the study showed an increase in thermal conductivity by a factor of 4 when the mass fraction of the graphite in the composite was increased to 16.5%. The specific heat of the composite PCM (CPCM) decreased as the thermal conductivity increased, while the latent heat remained the same as the PCM component. In addition, the phase transition temperature was not influenced by the addition of expanded graphite. To explore the feasibility of the CPCM for practical applications, a numerical solution of the phase change transition of a small cylinder was derived. Finally, a numerical simulation and the experimental results for a known volume of CPCM indicated a reduction in solidification time by a factor of 6. The numerical analysis was further explored to indicate the optimum operating Biot number for maximum efficiency of the composite PCM thermal energy storage.