Energy Storage最新文献

This current investigation involves an experimental inspection of adding porous medium and phase change material (PCM) above the absorber surface to enhance the performance of a single slope and single basin solar water distiller system. To demonstrate the effectiveness of adding porous medium and PCM, the performance of the modified system and conventional system is compared under similar operating conditions. The system that uses porous medium and PCM is called MSS-FPP, whereas the conventional system is called MSS-F. Rectangular fins are fixed above the absorber plate for both models. For MSS-FPP model, three different types of porous medium (stones, nuts, and black glass balls) are used in addition to paraffin wax filled inside circular tubes as a PCM. The data are collected in November and December 2023 in Mosul City, Iraq. The experiments are carried out under different water depths. The findings confirm that the performance of MSS-FPP model is better than MSS-F model by 41.32% (for water depth 3 cm) and 30.61% (for water depth 5 cm). The results also indicated that the water productivity of MSS-FPP model is higher than MSS-F model by 41.67% (for water depth 3 cm) and 30.65% (for water depth 5 cm). For MSS-FPP model, the maximum water productivity and efficiency are obtained when using black glass balls as compared to nuts and stones types, where the highest water temperature and water productivity values are found equal 54°C and 1.01 kg/m² for water depth 3 cm. The enhancement in the performance of modified solar water distiller system (MSS-FPP) shows that using a porous medium and PCM has considerable impacts on the evaporation rate, heat exchange, and rate of heat transfer.

In this study, we present a strategy of synergistic lowest-temperature annealing, and solvent-casting to synthesize Fe-doped ZnO anchored porous activated carbon-based ternary nanocomposite for asymmetric supercapacitor applications with an extended potential window of 1.2 V. The prepared nanocomposite shows a “stacked-table” like morphology with pores in the surface and walls of the carbon matrix. The incorporation of Fe-doped ZnO onto the carbon skeleton improves the conductivity by controlling morphology and specific capacitances through fast electron transfer property. The prepared nanocomposite delivers a specific capacitance of ~930 Fg⁻¹ at 1 Ag⁻¹. The fabricated ASC device delivers the specific capacitance of ~480 Fg⁻¹, energy and power density of ~266.6 Whkg⁻¹ and ~1998.5 Wkg⁻¹ at a current of 1 and 10 Ag⁻¹ respectively, respectively maintaining its remarkable capacitance of about 98.5% across 10 000 cycles. This superior performance can be attributed to the significant contact between the positive/negative electrode and the electrolyte which reduces the pathway of the diffused ions and enhances the conductivity of the porous carbon material aiding the electrons to travel towards the current collector. The low-temperature annealing and solvent casting strategy pave the way for the use of facile synthesis of Fe-doped ZnO as an efficient material for high-power supercapacitor applications.

This study investigates the thermal properties of lauric acid (LA) as a phase change material (PCM) using the K-Means clustering method to analyze the melting characteristics. This study focuses on the optimization of PCMs using a hybrid methodology of analytic hierarchy process (AHP) and K-Means clustering. LA, enhanced with zinc oxide (ZnO) nanoparticles, was evaluated for its thermal performance. LA's suitability as a PCM is evaluated based on initial temperature, heating rate, final temperature, and time to melt. AHP was employed to determine the weightage for three critical outcomes: latent heat, melting point, and thermal conductivity. The weightages assigned were 59%, 31%, and 11%, respectively, reflecting the relative importance of each outcome in assessing the efficiency of LA as a PCM. Furthermore, K-Means clustering was then applied to categorize the data based on these weighted outcomes. AHP was utilized to determine the weightage of input parameters, assigning 27% to initial temperature, 15% to heating rate, and 22% to final temperature, underscoring their significance in the analysis. The optimal input conditions identified were an initial temperature of 24.8°C, a ieating rate of 5.6°C/min, a final temperature of 81.4°C, and a time to melt of 10.6 min. These conditions resulted in optimal outcomes of 208 J/g for latent heat, a melting point of 80.9°C, and a thermal conductivity of 0.21 W/m·K. This hybrid approach provides a robust framework for optimizing PCM performance, facilitating enhanced thermal energy storage and release in practical applications.

Industrial processes often generate substantial amounts of wastewater with significant thermal energy content, which is typically discarded as waste. A promising approach to increase energy efficiency and advance sustainable resource management is waste water heat recovery. Utilizing a phase change material (PCM) to extract waste heat from wastewater and transfer it to cold water is an innovative method that separates the demand and supply of heat, while also integrating storage and transmission within a single heat exchanger (HE). A 3D numerical model of PCM-based HE is developed and simulated. The thermal behavior of PCM and preheating of cold water are investigated in this study. In order to increase the thermal conductivity of the PCM, fins are strategically positioned. Around 71.13% of melting time is reduced by adding fins. Further, the 10° orientation of the fins is also numerically observed and it is found that it helps to improve natural circulation of molten PCM. Thus, melting time is reduced by 34% compared to the vertical fin. A 3.5°C–4.5°C temperature rise in cold water is obtained with the inclined fin, which is 14.28% higher than the vertical fin model.

Due to the advantages of high energy density and constant temperature, phase change energy storage technology has attracted much attention in energy saving and efficient utilization of energy. In this paper, Fluent software is used to simulate and analyze the heat storage characteristics of six new thermal storage units: corrugated tube, hyperbolic-shape, non-hyperbolic-shape, symmetric frustum-shape, non-frustum-shape, and bow-shape. The results show that the melting rate of the non-hyperbolic-shape phase change unit is significantly higher than that of the circular tube, the heat storage time is shortened by 22.52%, and Ra* reaches 0.0086. Second, the effects of the radius difference (δ) between the inlet and outlet of the non-hyperbolic-shape phase change unit and the asymmetric position (s) on the heat storage process are studied. The results show that when δ increases from 2 to 10 mm, the melting time of phase change material (PCM) is shortened by 22.89%, that is, the average heat transfer rate between PCM and heat transfer fluid increases with the increase of δ. On the other hand, the average heat storage rate of the heat storage unit decreases first and then increases with the increase of s. When δ = 10 mm, s = 35 mm is the best working condition, the average heat storage rate of the non-hyperbolic-shape thermal storage unit reaches 34.3 J/s. This study can provide new ideas and references for the optimization design of latent heat storage units and the progress of experiments.

Reliable energy sources are crucial for both economic growth and quality of life. In developing countries, where expensive fuels are often the primary energy source, governments are exploring innovative solutions like small-scale, IoT-based projects to achieve energy independence in buildings. This research investigates the integration of renewable energy technologies, statistical modeling, cloud computing, and IoT to develop a self-managing energy system for buildings. The system prioritizes renewable sources, specifically monocrystalline solar cells with 20% efficiency for photovoltaic (PV) energy and flat plate collectors with 90% efficiency and minimal energy loss for thermal energy. Thermal energy is stored in paraffin wax, chosen for its high storage efficiency and thermal properties. The system also utilizes an absorption chiller with a high coefficient of performance (COP) to provide cooling using solar thermal energy. The building's energy loads are categorized as A, B, C, and D, each utilizing both PV and thermal energy. A SCADA system oversees the operation, monitoring the on–off status of these loads. The system is designed for continuous operation, with simulations conducted using Anaconda Jupyter Notebook and Python. This model aims to offer a sustainable and efficient energy solution for buildings, meeting energy demands while optimizing energy use.

In this work, x(1H-indol-2-yl)benzonitrile; where x = ortho or para were used to synthesize boehmite composites using one-pot electrochemical method in the presence of NaCl as an electrolyte. The prepared composites were characterized using UV–vis, XRD, SEM, and BET. The measurements showed that the type of substituents (ortho, para) had an effect on the resulting nanostructure of the composites, which appeared in the form of nanosheets and nanoballs. The composites were used as materials to store hydrogen at different temperatures (77, 173, 223, and 273 K) under different pressures (10–90 bar) in order to determine the equilibrium pressure for each nanocomposite. The study demonstrated that the composite boehmite-ortho-(1H-indol-2-yl)benzonitrile nano balls has a storage capacity of 3.82 wt% at an equilibrium pressure of 75 bar, while the composite boehmite-para-(1H-indol-2-yl)benzonitrile nanosheets have the highest storage capacity of 4.49 wt% and an equilibrium pressure of 45 bar.

Batteries, particularly lithium-ion batteries, are sensitive to temperature changes. Battery thermal management systems (BTMS) are essential in various battery-powered applications, especially electric vehicles (EVs) and portable electronic devices. This study examines the importance of phase change material (PCM) in battery packs using numerical analysis. An examination is conducted on a battery pack consisting of 18 650 battery cells arranged in a 5 × 5 configuration. A comparative analysis is performed to evaluate the thermal efficiency of the battery pack with and without PCM. The study examines the influence of ambient conditions and charging rates on the selection of PCM for battery packs. A hybrid cooling solution utilizing PCM and a water tube has also been investigated against conventional passive PCM-based BTMS. Additionally, two types of fins, namely circular and spiral fins, are introduced to improve the heat transfer rate. PCM-based cooling systems are most effective when the ambient temperature is below the melting temperature of the PCM. However, when the ambient temperature exceeds the melting temperature of the PCM, this cooling system outperforms conventional PCM-based cooling. The maximum temperature is found as 319, 316.9, and 315.3 K using without fin, circular fin and spriral fina, respectively. The spiral fins are found more effective than circular fins under high ambient temperature. In conclusion, The PCM-with spiral-fin system demonstrates notable benefits in high-temperature environments.