Energy最新文献_第2页

Adaptive distribution topology learning on distributed source energisation and islanding

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-25 DOI: 10.1016/j.energy.2025.135183

Sangkeun Moon

Monitoring and controlling power sources in the distribution system can be challenging, especially when integrating distributed energy sources (DERs). The presence of multiple DERs introduces fluctuation and complexity, which can result in entangled power flow directions. The direction of power flow represents a pivotal signal in this study to understand the DER behaviours regarding their power injection and intermittent characteristics. Therefore, the paper introduces directional connectivity through graph analysis to tackle uncertainty from DER interconnections where islanding detection and restoration rely on acyclic and unidirectional energy flows. We propose the topology imbalance concept to manage directional power flow, loops, and interconnections. Our model employs phase signals to track topology changes and build grid structures without prior configuration information. The process is explored using radial subsystems with multi-directional energy supply scenarios. The findings demonstrate that the model can create diverse network configurations by integrating DER interconnections and islanding in steady state radial systems. The study explores the relationship between energisation and source injections, focusing on the back-feeding behaviour of DERs. Test results indicate index ranges of up to 198 % for imbalance and 179 % for energisation, reflecting the locations of DER sources and the energy injected.

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引用次数: 0

Study on pyrolysis characteristics of typical thermal insulation materials under light aging

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-24 DOI: 10.1016/j.energy.2025.135238

Wenlong Zhang , Rongkun Pan , Jian Wang , Chang Lu , Miling Liu , Yanming Ding

Due to the shedding of building facades, thermal insulation materials (TIMs) are usually aged by sunlight, leading to changes in physical and chemical performance. However, there are few studies on the fire hazards of TIMs under light aging. Pyrolysis is the first process of fire occurrence, and the pyrolysis gas provides gaseous fuel for gas-phase combustion. Therefore, pyrolysis characteristics of TIMs under light aging were studied in this study. Extruded polystyrene (XPS) was aged up to 180 days by accelerated aging experiments, and its pyrolysis characteristics were studied using thermogravimetric analysis. The kinetic parameters were estimated by the Coats-Redfern method and optimized using multiple optimization algorithms. Subsequently, the Fourier transform infrared spectrometric technique was applied to analyze the pyrolysis products. The results showed that the chalking appeared and the structure of XPS was destroyed with light aging. Pyrolysis mechanisms changed and the kinetic parameters decreased. Pyrolysis was easier to occur and the reaction required less energy, indicating an increase in its fire hazards. New functional groups were generated, and the intensity of vibration bands was strengthened. This study contributes to understanding of fire risk of aging TIMs and taking appropriate measures to prevent material aging, thereby reducing fire accidents.

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引用次数: 0

Experimental study on the effects of simulated EGR on ammonia-diesel dual-fuel combustion in a constant volume chamber

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-24 DOI: 10.1016/j.energy.2025.135258

Yuqiang Li , Hongyi Cao , Ruoyun Lei , Chengwei Deng

This study investigates the effects of exhaust gas recirculation (EGR) on ammonia-diesel dual-fuel combustion through optical experiments in a constant volume chamber, varying ambient temperatures (700 K–800 K) and oxygen concentrations (11%–21 %). The results reveal that the combustion process can be divided into three stages based on flame characteristics: diesel premixed combustion, diesel diffusion combustion, and ammonia premixed combustion. As the ambient temperature and oxygen concentration decrease, the luminescence region of the NH₂ group narrows, and its luminescence intensity diminishes, indicating lower NO emissions. Compared to the decrease in oxygen concentration from 16 % to 11 %, the reduction from 21 % to 16 % has a less pronounced impact on ammonia-diesel combustion performance. The peak heat release rate (HRR) shows a non-monotonic trend, initially increasing and then decreasing as the temperature drops. Ammonia-diesel combustion deteriorates at extremely low ambient temperatures and oxygen concentrations, exhibiting a double-peak HRR. These findings suggest that mild EGR can be applied to real ammonia-diesel engines to effectively reduce NO emissions, although it may slightly compromise combustion performance.

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引用次数: 0

Energy demand security in OPEC+ countries: A revised 4As framework beyond supply security

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-24 DOI: 10.1016/j.energy.2025.135261

Ruike Ye , Xirui Yang , Yunheng Zhou , Changfeng Lin , Yiming Chen , Jiawei Chen , Mengying Bian

Research predominantly focus on assessing energy supply security, with minimal emphasis on evaluating energy demand security, which is critical for the OPEC + countries. This paper introduces a revised 4As framework that extends beyond energy supply security to establish an Energy Demand Security Index (EDSI). The findings from the expert survey, which integrated the Delphi Method and AHP, emphasize the importance of resource endowment, the national economy's reliance on oil, and the diversification of oil exports in evaluating energy demand security. The results of the integrated ranking and dimensional analysis indicate that no surveyed nation demonstrated outstanding performance in all four dimensions. Algeria and Russia were identified as the top-ranking nations between 2010 and 2022. By employing matrix analysis and longitudinal group analysis, OPEC + countries were classified into three groups: stable (e.g., Algeria), rising (e.g., Saudi Arabia), and declining (e.g., Russia). Well-rounded performers are better equipped to handle the intricacies of energy demand security. Saudi Arabia's focus on diversification has helped to enhance its EDSI score, whereas Russia's decline is primarily affected by energy sanctions. The conclusions have important implications for shaping policies in countries that rely on energy exports for their sustainable development.

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引用次数: 0

Empowering educational inequality reduction: Does energy poverty eradication matter?

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-24 DOI: 10.1016/j.energy.2025.135251

Xiaomeng Zhao , Jun Zhao , Yalin Lei , Hongyun Huang

To test the macroeconomic impact of energy poverty (EEPT) on educational inequality, a panel of 30 provinces from 2002 to 2021 is utilized to conduct an empirical check. Besides, heterogeneity of geographical location, administrative levels, and educational gender inequality is explored, and whether educational level and income inequality are valid paths is discussed. The primary conclusions insist that: (1) Greatly alleviating EEPT can efficiently narrow educational inequality, and reducing EEPT has a substantially more significant impact on lowering educational inequality for women than for men. EEPT has an inverted U-shaped relationship with gender inequality in education; (2) the influence of EEPT on provincial, male, and female educational inequality in the eastern area is insignificant, while the positive effect in the midwestern area is noticeable; EEPT has the most significant positive impact on educational inequality in rural areas, followed by town, and the smallest in urban areas; (3) the gradual increase of EEPT will expand the degree of gender inequality; and (4) the mechanism analysis proves that income inequality and educational level hold as transmission paths between EEPT and educational inequality. Based on these four findings, some policy implications are put forward.

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引用次数: 0

A primer on verti-zontally differentiated peer-to-peer energy intraday trading platforms with and without customization

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-24 DOI: 10.1016/j.energy.2025.134980

Vitor Miguel Ribeiro, Isabel Soares

This study analyzes a two-sided market where two platforms compete to attract agents from two distinct sides to participate in peer-to-peer (P2P) energy intraday trading. These intermediaries are differentiated both vertically and horizontally and engage in price competition to attract additional members on both sides. While considering quality disparities at the intermediation level, we also examine the possibility that both platforms may choose to customize their trading services. In the absence of service customization (ASC) regime, results confirm that equilibrium outcomes depend on the interaction between the strength of indirect network effects and the degree of quality differentiation between platforms. Notably, regardless of whether horizontal or vertical dominance prevails, the intensity of inter-group externalities consistently promotes pro-competitive effects in private equilibrium. However, when platforms opt for the provision of service customization (PSC) regime, inter-group externalities no longer impact equilibrium prices and profits when the quality discrepancy between platforms is sufficiently high. This finding not only theoretically challenges conventional wisdom in network effects literature but also suggests to practitioners that the pro-competitive role of inter-group externalities disappears in this specific market condition, where some agents already enjoy a significantly high reputation, making the internalization of indirect network effects irrelevant. When that is the case, this research highlights the strategic role of customization diffusion, combined with asymmetric quality differences at the intermediation level, to mitigate intense price competition caused by inter-group externalities in P2P energy intraday trading systems. If regulators overlook this dynamic, the surplus traditionally enjoyed by incumbent operators at the distribution level – typically attributed to the persistence of a natural monopoly – may shift to those who preemptively establish high-quality platforms in institutional environments that support service customization.

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引用次数: 0

Urbanization and low-carbon transformation in China's agriculture: An empirical investigation

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-23 DOI: 10.1016/j.energy.2025.135242

Xiao Lei , Xingru Chen , Nan Wang , Jiayi Wu , Bin Zhang

As one of the world's largest carbon emitters, China faces significant challenges in managing agricultural carbon emissions (ACE). Urbanization (UR), propelled by economic development, plays a crucial role in reducing carbon emissions by facilitating agricultural structural adjustments, enhancing production efficiency, and promoting technological advancements. This study employs nighttime light data to model UR, thus overcoming the problems in data acquisition, update and accuracy of traditional methods, comparing it with indicators such as built-up area, population and economy. The results demonstrate that both ACE and UR are spatially spread from east to west, with UR demonstrating a strong capacity to reduce ACE—a conclusion corroborated by robustness analysis. The positive impact of UR on emission reduction remains consistent across different regions and innovation levels. Furthermore, through intermediary mechanisms, UR enhances its emission reduction impact by stimulating technological innovation and high-quality economic transformation, generating positive spatial spillover effects in neighboring regions. This study provides valuable insights for government policy formulation, presents a fresh perspective on UR and agricultural carbon emissions reduction (ACER) strategies, and serves as a reference for local governments seeking to harness UR for technological innovation and economic development.

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引用次数: 0

Multi-criteria optimization of nanofluid-based solar collector for enhanced performance: An explainable machine learning-driven approach

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-23 DOI: 10.1016/j.energy.2025.135212

Anjana Sankar , Kritesh Kumar Gupta , Vishal Bhalla , Daya Shankar Pandey

This study presents a novel hybrid framework that leverages machine learning to enhance the performance of nanofluid-based solar collectors (NBSCs). The framework is designed to identify the optimal control variables required to meet multiple performance criteria (such as simultaneously maximizing outlet temperature, thermal efficiency, and optical efficiency). This study introduces an end-to-end multi-criteria optimization framework that combines numerical simulations with a Gaussian process regression (GPR) and genetic algorithm (GA) for designing optimized NBSCs. In this approach, a minimal number of random samples are selected using Monte-Carlo sampling to perform numerical simulations. The control variables of the system are varied within practical ranges, and key performance metrics such as outlet temperature [T_o (°C)], thermal efficiency (η_t), and optical efficiency (η_o) are recorded. The input and output data are utilized to develop a computationally efficient GPR model. The generalization capability of the developed explainable machine learning (xML) models allowed for various data-intensive analyses, including sensitivity analysis, uncertainty quantification, interactive influence of control variables, and multi-objective optimization. The proposed computational framework helped explore previously unknown territory, leading to the identification of optimal settings for simultaneously maximizing all the responses. The optimal parameters led to a simultaneous improvement in the responses, with a 23.44 °C rise in outlet temperature, a 37.48 % increase in thermal efficiency, and a 28.62 % boost in optical efficiency, compared to the base dataset. The developed framework is rigorously tested to ensure its robust generalization and its applicability to calibrate other physical systems. The results of this study offer valuable insights for designing optimal NBSCs with improved operational performance.

{"title":"Multi-criteria optimization of nanofluid-based solar collector for enhanced performance: An explainable machine learning-driven approach","authors":"Anjana Sankar , Kritesh Kumar Gupta , Vishal Bhalla , Daya Shankar Pandey","doi":"10.1016/j.energy.2025.135212","DOIUrl":"10.1016/j.energy.2025.135212","url":null,"abstract":"<div><div>This study presents a novel hybrid framework that leverages machine learning to enhance the performance of nanofluid-based solar collectors (NBSCs). The framework is designed to identify the optimal control variables required to meet multiple performance criteria (such as simultaneously maximizing outlet temperature, thermal efficiency, and optical efficiency). This study introduces an end-to-end multi-criteria optimization framework that combines numerical simulations with a Gaussian process regression (GPR) and genetic algorithm (GA) for designing optimized NBSCs. In this approach, a minimal number of random samples are selected using Monte-Carlo sampling to perform numerical simulations. The control variables of the system are varied within practical ranges, and key performance metrics such as outlet temperature [<em>T</em><sub><em>o</em></sub> (°C)], thermal efficiency (<em>η</em><sub><em>t</em></sub>), and optical efficiency (<em>η</em><sub><em>o</em></sub>) are recorded. The input and output data are utilized to develop a computationally efficient GPR model. The generalization capability of the developed explainable machine learning (xML) models allowed for various data-intensive analyses, including sensitivity analysis, uncertainty quantification, interactive influence of control variables, and multi-objective optimization. The proposed computational framework helped explore previously unknown territory, leading to the identification of optimal settings for simultaneously maximizing all the responses. The optimal parameters led to a simultaneous improvement in the responses, with a 23.44 °C rise in outlet temperature, a 37.48 % increase in thermal efficiency, and a 28.62 % boost in optical efficiency, compared to the base dataset. The developed framework is rigorously tested to ensure its robust generalization and its applicability to calibrate other physical systems. The results of this study offer valuable insights for designing optimal NBSCs with improved operational performance.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"320 ","pages":"Article 135212"},"PeriodicalIF":9.0,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143508886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study of energy dissipation mechanisms and pressure pulsation spectrums in a vertical axial flow pumping station on the ultra-low head condition based on multiple analysis methods

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-23 DOI: 10.1016/j.energy.2025.135227

Shuaihao Lei , Li Cheng , Weigao Sheng

In the context of global energy shortages, the efficient and safe operation of pumping stations is essential for improving energy utilization and achieving energy conservation and emission reduction goals. Vertical axial flow pumping stations, especially those operating under ultra-low head conditions, face specific challenges related to energy dissipation and pressure pulsations — both critical to enhancing overall efficiency. This study employed an entropy production head loss model and pressure pulsation test to assess the energy dissipation and pressure pulsation characteristics of the pump system. Results showed that the total head loss under ultra-low head condition (0.18

H_{d}

) is 1.26 times higher than under design condition (

H_{d}

). The misalignment between the outlet velocity angle of impeller and the inlet vane angle of guide-vane was identified as the primary factor contributing to energy loss and hydraulic instability. Additionally, wall effects caused significant head loss near the blade and shroud regions. Under non-design conditions, pressure pulsations in the impeller and guide-vane regions fluctuated significantly. To analyze these fluctuations, feature mode decomposition (FMD) and energy flow density (EFD) methods were applied, demonstrating a strong correlation between EFD and peak-to-peak value (PPV). These findings offer important insights for optimizing pump station design and improving operational efficiency.

{"title":"Study of energy dissipation mechanisms and pressure pulsation spectrums in a vertical axial flow pumping station on the ultra-low head condition based on multiple analysis methods","authors":"Shuaihao Lei , Li Cheng , Weigao Sheng","doi":"10.1016/j.energy.2025.135227","DOIUrl":"10.1016/j.energy.2025.135227","url":null,"abstract":"<div><div>In the context of global energy shortages, the efficient and safe operation of pumping stations is essential for improving energy utilization and achieving energy conservation and emission reduction goals. Vertical axial flow pumping stations, especially those operating under ultra-low head conditions, face specific challenges related to energy dissipation and pressure pulsations — both critical to enhancing overall efficiency. This study employed an entropy production head loss model and pressure pulsation test to assess the energy dissipation and pressure pulsation characteristics of the pump system. Results showed that the total head loss under ultra-low head condition (0.18 <span><math><mrow><msub><mi>H</mi><mi>d</mi></msub></mrow></math></span>) is 1.26 times higher than under design condition (<span><math><mrow><msub><mi>H</mi><mi>d</mi></msub></mrow></math></span>). The misalignment between the outlet velocity angle of impeller and the inlet vane angle of guide-vane was identified as the primary factor contributing to energy loss and hydraulic instability. Additionally, wall effects caused significant head loss near the blade and shroud regions. Under non-design conditions, pressure pulsations in the impeller and guide-vane regions fluctuated significantly. To analyze these fluctuations, feature mode decomposition (FMD) and energy flow density (EFD) methods were applied, demonstrating a strong correlation between EFD and peak-to-peak value (PPV). These findings offer important insights for optimizing pump station design and improving operational efficiency.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"320 ","pages":"Article 135227"},"PeriodicalIF":9.0,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143508884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

In situ testing and model optimization of a smart façade system for zero carbon and enhanced comfort in buildings

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-02-22 DOI: 10.1016/j.energy.2025.135235

Yang Ming , Mingke Hu , Yanping Yuan , Yupeng Wu

Integrating Thermotropic materials into the Parallel Slat-Transparent Insulation Material (TT PS-TIM) double-glazed system enhances indoor daylight comfort and reduces energy consumption through solar regulation and improved thermal resistance. However, the dynamic nature of the system is crucial to determine the daylight and energy performance as the transition between its clear and translucent states results in significant variations in solar transmission/absorption. This study assessed the dynamic optical and thermal performance of the developed system through outdoor experiment. An optimized numerical model for its dynamic state prediction was developed incorporating factors of window surface temperature and slats solar absorption, and validated experimentally, therefore improve the accuracy of dynamic state prediction and further annual building energy consumption. Findings revealed that TT PS-TIM outperformed traditional systems in solar regulation. Meanwhile, the slat-temperature from optimized model showcased a good agreement with experiment data with a deviation of less than 1.3 °C (4.1%). Compared with optimized model, the current simplified model indicated a significantly error for the dynamic state of the TT PS-TIM system, with differences ranging from 23.83% to 64.82% for annual translucent duration, affected by locations, window-to-wall ratios, and slat intervals, leading to increased cooling energy consumption and slight decreases in heating/lighting energy use.

{"title":"In situ testing and model optimization of a smart façade system for zero carbon and enhanced comfort in buildings","authors":"Yang Ming , Mingke Hu , Yanping Yuan , Yupeng Wu","doi":"10.1016/j.energy.2025.135235","DOIUrl":"10.1016/j.energy.2025.135235","url":null,"abstract":"<div><div>Integrating Thermotropic materials into the Parallel Slat-Transparent Insulation Material (TT PS-TIM) double-glazed system enhances indoor daylight comfort and reduces energy consumption through solar regulation and improved thermal resistance. However, the dynamic nature of the system is crucial to determine the daylight and energy performance as the transition between its clear and translucent states results in significant variations in solar transmission/absorption. This study assessed the dynamic optical and thermal performance of the developed system through outdoor experiment. An optimized numerical model for its dynamic state prediction was developed incorporating factors of window surface temperature and slats solar absorption, and validated experimentally, therefore improve the accuracy of dynamic state prediction and further annual building energy consumption. Findings revealed that TT PS-TIM outperformed traditional systems in solar regulation. Meanwhile, the slat-temperature from optimized model showcased a good agreement with experiment data with a deviation of less than 1.3 °C (4.1%). Compared with optimized model, the current simplified model indicated a significantly error for the dynamic state of the TT PS-TIM system, with differences ranging from 23.83% to 64.82% for annual translucent duration, affected by locations, window-to-wall ratios, and slat intervals, leading to increased cooling energy consumption and slight decreases in heating/lighting energy use.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"320 ","pages":"Article 135235"},"PeriodicalIF":9.0,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0