Energy最新文献

{"title":"Integrated PD-HT-FEM simulation of fracture networks and heat extraction in enhanced geothermal systems under coupled thermal-hydraulic-mechanical condition","authors":"Luming Zhou,&nbsp;Zhihong Zhao,&nbsp;Yunzhe Jin","doi":"10.1016/j.energy.2025.136242","DOIUrl":"10.1016/j.energy.2025.136242","url":null,"abstract":"<div><div>Enhanced geothermal systems (EGS) are an effective approach for exploiting geothermal energy from hot dry rock (HDR). Conducting a comprehensive simulation that encompasses the entire process from EGS hydraulic fracturing to heat extraction by the working fluid, and then outflow through the production well, is an important but numerically challenging task. Although many previous studies thoroughly analyzed the thermal-hydraulic-mechanical (THM) coupling mechanism in fractured rock masses during EGS operation, the considered fracture network geometric models were directly predefined without considering stimulation process. In this paper, combining peridynamics (PD), Hough transform (HT), and finite element method (FEM), we propose an integrated simulation method for the entire process containing hydraulic stimulation and heat extraction during long-term operation. The results indicate that the increases in elastic modulus and thermal expansion coefficient of HDR cause a decrease in the outlet temperature of the production well, an increase in the heat extraction ratio, and an earlier thermal breakthrough. The variations in these indices obtained using the PD-HT-FEM method are significantly greater than those obtained using a same geometry network model. This study provides a method for simulating and predicting EGS operations, highlighting the importance of conducting a comprehensive analysis of the fracturing and heat extraction.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"326 ","pages":"Article 136242"},"PeriodicalIF":9.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855987","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}

{"title":"Energy-efficient train control: Online train operation considering DC traction network","authors":"Yang Peng ,&nbsp;Rang Xu ,&nbsp;Haifeng Luo ,&nbsp;Chaoxian Wu ,&nbsp;Mingyang Pei ,&nbsp;Kai Lu ,&nbsp;Shaofeng Lu","doi":"10.1016/j.energy.2025.136057","DOIUrl":"10.1016/j.energy.2025.136057","url":null,"abstract":"<div><div>The network efficiency and real-time power of the urban rail transit traction power supply system (TPSS) are closely linked to train speed and output power. Collaborative optimization of energy-efficient train control (EETC) and railway systems can reduce TPSS-level energy consumption. This paper proposes a high-accuracy, high-efficiency EETC model integrated with TPSS-train integration to minimize TPSS energy, utilizing a shrinking horizon model predictive control (SHMPC) framework. The proposed iterative model uses spatial-to-temporal domain conversion to update the train’s future operational states and network topology. By optimizing spatial discretization and iteration count, the model reduces solution deviations caused by speed limit and time discrepancies, enhancing its accuracy. With a minimum operation time of 0.066 s per iteration. The result reveals that less mechanical energy does not necessarily equate to less traction energy sourced from the TPSS. Compared to the distance-based EETC model, the proposed model achieves an 11.74% savings rate in traction energy from the TPSS. Within this, the proportion of traction energy loss is 8.53%, indicating less traction energy loss than the total energy loss incurred by the model without considering TPSSs-train integration.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"326 ","pages":"Article 136057"},"PeriodicalIF":9.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869341","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}

{"title":"Analysis of multi-mode combustion and performance in a marine diesel/natural gas dual-fuel engine based on an irreversible equivalent combustion cycle theory","authors":"Liping Yang ,&nbsp;Shuaizhuang Ji ,&nbsp;Jacek Hunicz ,&nbsp;Rui Wang ,&nbsp;Ali Zare ,&nbsp;Yuqi Su ,&nbsp;Deyang Ji","doi":"10.1016/j.energy.2025.136248","DOIUrl":"10.1016/j.energy.2025.136248","url":null,"abstract":"<div><div>Diesel/natural gas dual-fuel engines offer the advantages of higher thermal efficiency and lower carbon dioxide emission while breaking the NOx-PM trade-off caused by diffusion-dominated combustion in diesel engines. However, the large reactivity gradient between diesel and natural gas leads to more complex ignition and multi-stage heat release process. Traditional pressure and heat release rate-based analyses, as well as the ideal thermodynamic cycle theory, are insufficient to identify multi-stage heat release under different combustion modes, and especially cannot estimate the correlation of specific thermodynamic processes with engine performance and emissions. In this paper, an irreversible equivalent combustion cycle theory is proposed to reveal the effects of natural gas thermal substitution ratio (NG-TSR) and high reactivity diesel injection strategies on the multi-mode combustion and performance under a typical ship propulsion condition of the engine speed of 1134 rpm and load of 25 %. The results show that as NG-TSR decreases, the heat release ratio of constant volume combustion (Q-CVC) and constant pressure combustion processes (Q-CPC) increases, while the reduction in late combustion (LC) leads to a higher indicated thermal efficiency (ITE is up to 41.4 %). At the same time, total hydrocarbon (THC) emission can be reduced by more than 70 %, while NOx emission increases. Under the single-injection strategy, CO₂ emission is dominated by NG-TSR, while the ratio of Q-CVC in the whole combustion cycle has the most important effect on NOx and THC emissions, with effect significances of +63 % and -72 %, respectively. The split-injection strategy effectively converts the LC stage to the CVC and CPC stages, and pre-injection ratio (PR) shows a strong negative correlation with THC and CO emissions, as well as brake specific energy consumption. Moreover, CO₂ and NOx emissions can be further controlled by optimizing the contributions of these three combustion stages.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"326 ","pages":"Article 136248"},"PeriodicalIF":9.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855642","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}

{"title":"A comprehensive review of H2 physical behavior and H2-rock-microbial interactions in underground hydrogen storage","authors":"Zanfu Xiong ,&nbsp;Jian Hou ,&nbsp;Qingjun Du ,&nbsp;Zheng Chen ,&nbsp;Xiangquan Lu ,&nbsp;Yongge Liu ,&nbsp;Bei Wei ,&nbsp;Teng Lu","doi":"10.1016/j.energy.2025.136226","DOIUrl":"10.1016/j.energy.2025.136226","url":null,"abstract":"<div><div>The global imperative to achieve carbon neutrality has significantly intensified research efforts toward large-scale underground hydrogen storage. Nevertheless, the efficient implementation of underground hydrogen storage systems faces substantial challenges due to physical and chemical losses of H₂, as well as complex H₂-rock-microbial interactions. A comprehensive understanding of these interactions, coupled with the development of robust H₂ consumption assessment models, is therefore critically needed. This review systematically addresses the key physical and biochemical challenges in underground hydrogen storage, including H₂ dissolution, adsorption, diffusion, capillary trapping, and H₂-mineral-microbial interactions. From both experimental and simulation perspectives, the review critically analyzes the influence of critical factors such as temperature, pressure, saline electrolyte composition, rock mineralogy, and heterogeneous pore structures on the physical behavior of H₂. Furthermore, the chemical characteristics of H₂ are examined, with a focus on alterations to porous structures induced by H₂-mineral reactions and pore blockage caused by hydrogenotrophic microorganisms. Existing models for characterizing the physical behavior of H₂ and H₂-rock-microbial interactions are evaluated, with an emphasis on their strengths and limitations. Additionally, the biological, mechanical, and seepage behaviors associated with the transport of multi-state hydrogenotrophic microorganisms, microfracture, and cyclic H₂ storage are discussed. This review provides critical insights for refining characterization models of hydrogenotrophic microorganisms and improving H₂ recovery rates in underground hydrogen storage. By advancing the understanding and optimization of underground hydrogen storage, this work contributes to the development of sustainable, carbon-neutral energy systems.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"326 ","pages":"Article 136226"},"PeriodicalIF":9.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143881630","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}

{"title":"Revealing temporal and spatial variations in CO2 emission factor of electricity generation in Japan","authors":"Hideki Shimada ,&nbsp;Tomonori Honda ,&nbsp;Yuya Imamura ,&nbsp;Ruth Anne Gonocruz ,&nbsp;Akito Ozawa","doi":"10.1016/j.energy.2025.136237","DOIUrl":"10.1016/j.energy.2025.136237","url":null,"abstract":"<div><div>The electricity generation sector in many countries is undergoing drastic changes toward decarbonization. A major driver of this change is the rapid integration of renewable energy, the availability of which varies temporally and spatially. To evaluate how such variations affect CO₂ emissions from electricity generation, this study measured the average emission factor across 10 different electricity service areas in Japan. Using hourly generation data spanning seven years from each area, our study revealed substantial temporal and spatial variations in the emission factor. Specifically, the results show (1) significant intraday variation with smaller values during daytime hours, (2) yearly variation with decreasing values over time, and (3) substantial spatial variation in both temporal variation and magnitude. We also used real consumption data of heat pump water heaters to simulate the extent to which CO₂ emissions can be mitigated by shifting their operation schedules from midnight to daytime, finding that households can reduce CO₂ emissions by 158 kg annually on average.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"326 ","pages":"Article 136237"},"PeriodicalIF":9.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875003","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}

{"title":"Experimental study of leakage diffusion in supercritical/dense phase CO2 pipelines","authors":"Qihui Hu ,&nbsp;Yaqi Guo ,&nbsp;Junwen Chen ,&nbsp;Buze Yin ,&nbsp;Yuxing Li ,&nbsp;Mingzhuo Li ,&nbsp;Yifei Wang ,&nbsp;Yu Wu ,&nbsp;Jianlu Zhu ,&nbsp;Guangchun Song","doi":"10.1016/j.energy.2025.136217","DOIUrl":"10.1016/j.energy.2025.136217","url":null,"abstract":"<div><div>The risk of leakage of supercritical/dense-phase CO₂ pipelines during transportation is unavoidable, and CO₂ diffusion and low-temperature effects may cause harm to the surrounding environment and personnel. In order to reveal the variation rules of pressure, temperature and flow rate at the leakage port, as well as the distribution characteristics of CO₂ concentration and temperature in the diffusion zone, this study conducted several sets of large-scale CO₂ pipeline leakage experiments, which took into account the effects of different pressures, temperatures, and leakage port conditions. The lowest temperature at the leakage port was measured to reach −72.6 °C by an independently designed method of near-leakage port parameter measurement, and the flow integral calculation verified the generation of dry ice particles. For far-field diffusion, the concentration and temperature drop in the diffusion zone increased significantly with increasing pressure and leak port in the pipe, and decreased with increasing temperature in the pipeline. The diffusion distances for different concentration thresholds (1 %, 4 %, 10 %) are quantitatively analyzed and the hazard distance is classified according to 4 % (Immediately Dangerous to Life or Health, IDLH). The low temperature distribution pattern is discussed and the diffusion distance of 10 °C is analyzed, and the lowest temperature in the diffusion zone can be as large as −37.5 °C. Through the concentration and temperature distribution at different heights to reflect the characteristics of CO₂ heavy gas diffusion. The experimental data can provide a reference for engineering pipeline operation, and at the same time provide a validation benchmark for numerical simulation studies.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"325 ","pages":"Article 136217"},"PeriodicalIF":9.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848727","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}

{"title":"Performance comparison of direct and flash steam generating heat pump using R1233zd(E) for waste heat recovery","authors":"Yishuang Liu,&nbsp;Bingdong Wang,&nbsp;Chuang Wang,&nbsp;Lixin Liu,&nbsp;Tianrui Sun,&nbsp;Yaoxiang Han,&nbsp;Ziwen Xing","doi":"10.1016/j.energy.2025.136211","DOIUrl":"10.1016/j.energy.2025.136211","url":null,"abstract":"<div><div>The steam generating heat pump, capable of producing steam from waste heat, is one of the promising technologies for energy conservation and emission reduction in the industrial sector. In this study, a simulation model for the steam generating heat pump is developed and validated using an experimental test rig with R1233zd(E) as the working fluid. The model is utilized to compare the performance of two SGHP system configurations. Each configuration has its own advantages: the steam production of FSGHP is, on average, 3.7 % higher than that of DSGHP, while the <em>COP</em> of DSGHP is, on average, 0.17 higher than that of FSGHP. A new performance evaluation index for SGHP, <em>COP</em><strong>_steam,</strong> is proposed. The quantitative impacts of the steam compressor and preheater on the system performance are assessed. The results showed that the introduction of the steam compressor could increase <em>COP</em>_steam by up to 1.2, while the preheater could enhance <em>COP</em>_steam by up to 0.16.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"326 ","pages":"Article 136211"},"PeriodicalIF":9.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863499","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}

{"title":"A hybrid WOA-CNN-BiLSTM framework with enhanced accuracy for low-voltage shunt capacitor remaining life prediction in power systems","authors":"Ningning Li,&nbsp;Weiyao Xu,&nbsp;Qiuyu Zeng,&nbsp;Yanjie Ren,&nbsp;Wenchuan Ma,&nbsp;Kezhu Tan","doi":"10.1016/j.energy.2025.136183","DOIUrl":"10.1016/j.energy.2025.136183","url":null,"abstract":"<div><div>Low-voltage shunt capacitors, as a good reactive power compensation component, have been widely used in power systems. However, when their capacitance decays to a threshold value, causing them to fail, it will seriously affect the safe operation of the system. This paper aims to study the remaining service life of low-voltage shunt capacitors and establish a data-based prediction model considering various environmental factors. Based on the traditional long short-term memory neural network prediction, an improved bidirectional long short-term memory network method combining convolutional neural networks and whale optimization algorithm is proposed, which improves the accuracy, speed, and robustness of prediction. The root mean square error (RMSE) and mean absolute error (MAE) before and after optimization are compared based on simulation. The simulation results show that compared with the traditional LSTM model, the RMSE of the prediction results of the WOA-CNN-BiLSTM model is reduced by 0.0117, and the MAE is reduced by 0.0063.Therefore, the WOA-CNN-BiLSTM model has higher accuracy and stability, can effectively reduce the power quality decline caused by the abnormal working state of the reactive power compensation equipment, so as to improve the operating efficiency of each equipment in the power system and extend its service life.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"326 ","pages":"Article 136183"},"PeriodicalIF":9.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859957","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}

{"title":"Energy consumption modeling and optimization of an eVTOL aircraft: Integrating weight, motor, and battery dynamics","authors":"Wei Li ,&nbsp;Rongguo Cheng ,&nbsp;Haihong Huang ,&nbsp;Akhil Garg ,&nbsp;Liang Gao","doi":"10.1016/j.energy.2025.136229","DOIUrl":"10.1016/j.energy.2025.136229","url":null,"abstract":"<div><div>Electric vertical takeoff and landing (eVTOL) aircraft, as a frontier technology in urban air mobility (UAM), have garnered significant attention from both academia and industry in recent years. This study addresses the high energy efficiency design challenge for eVTOL aircraft by proposing a multi-disciplinary design optimization (MDO) framework. Weight, motor efficiency, and electrochemical-aging-thermal coupled model of the battery were developed and integrated to construct a comprehensive whole-aircraft energy consumption analysis model. Using optimization algorithms, design parameters were optimized for various mission scenarios. Results demonstrate that the proposed optimization achieves an 11.44 % reduction in total energy consumption and a 15.81 % increase in maximum take-off mass compared to the baseline. Furthermore, the study identifies those key parameters, including cruise range, cruise height, and hover time, significantly influence the aircraft's energy consumption. This research not only provides theoretical foundations and design guidelines for developing commercially viable eVTOL systems with higher energy efficiency and longer battery life but also lays crucial theoretical groundwork for advancing the practical implementation and commercial application of eVTOL technology.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"325 ","pages":"Article 136229"},"PeriodicalIF":9.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848705","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}

{"title":"Impact of energy end-uses and efficiency indicators on the environmental policy stringency index","authors":"Guixian Tian ,&nbsp;Irfan Khan","doi":"10.1016/j.energy.2025.136232","DOIUrl":"10.1016/j.energy.2025.136232","url":null,"abstract":"<div><div>Energy end-uses and efficiency indicators express the extent of the environmental policy stringency index. Knowing how energy is used in different sectors enables formulating and implementing appropriate environmental policies targeting specific end-use sectors for energy-efficient strategies that support sustainable development goals. Integrating digital technology in energy systems further enhances efficiency by enabling smarter monitoring, management, and optimization of energy use across sectors, reinforcing environmental policies' effectiveness. This paper examines the impact of energy production and carbon emission indicators on the environmental policy stringency index in BRICS countries from 2000 to 2023, using total primary energy supply, energy intensity level of primary energy, and electricity production from renewable sources as control variables. The long-run estimates of Arellano–Bond dynamic panel-data estimation and robust random effect GLS regression with AR(1) disturbances indicate that energy production indicators, total primary energy supply, and electricity production from renewable sources are positively associated with environmental policy stringency and increased environmental policy stringency. Carbon emissions indicators and the energy intensity level of primary energy are negatively related to environmental policy stringency and decrease environmental policy stringency. The research includes interaction terms to investigate whether environmental policy stringency affects the connection between renewable energy generation and carbon emissions on energy intensity. Interaction models help research teams understand how dependent relationships function in the energy-environment system. Policymakers in the BRICS countries should integrate energy production indicators into policy frameworks, emphasizing renewable energy, energy efficiency, and carbon emission reduction to guide sustainable development, foster stricter environmental policies, and effectively address climate change challenges.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"326 ","pages":"Article 136232"},"PeriodicalIF":9.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855639","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}