Energy最新文献

{"title":"Scaling up ethanol fueled step micro-combustor for higher power generation","authors":"Vinay Sankar ,&nbsp;Sudipto Mukhopadhyay ,&nbsp;Ratna Kishore Velamati","doi":"10.1016/j.energy.2025.136328","DOIUrl":"10.1016/j.energy.2025.136328","url":null,"abstract":"<div><div>Stepped micro-combustors can be reliably used for portable power generation applications and can be scaled up in size to meet higher power requirements. The previous studies in stepped micro-combustors did not focus on the use of liquid fuels and the effect of scaling up (in size). This work numerically investigates ethanol combustion in stepped micro-combustors across increasing sizes, examining key performance parameters such as heat recirculation, flame structure, exergy destruction, and entropy generation. The finite volume method (FVM) and detailed chemistry are used to study the effect of scaling on premixed ethanol-air micro-combustor for five different micro-combustors of surface area to volume (<span><math><mrow><mi>S</mi><mo>/</mo><mi>V</mi></mrow></math></span>) ratio ranging from 2000 (smallest) to 1000 (largest). With scaling up, i.e., reducing surface area to volume (<span><math><mrow><mi>S</mi><mo>/</mo><mi>V</mi></mrow></math></span>) ratio, flame stabilizes closer to the inlet tube, with reduced heat recirculation through combustor walls. The reduced preheating of the incoming air–fuel mixture affects the chain branching reaction, which reduces flame speed. Scaling up increases the exergy efficiency (reaching a maximum of 86% at <span><math><mrow><mi>S</mi><mo>/</mo><mi>V</mi></mrow></math></span> ratio of 1000 at 25 W) and reduces the entropy generation rate (73% decrease at 25 W). With the reduction in the <span><math><mrow><mi>S</mi><mo>/</mo><mi>V</mi></mrow></math></span> ratio (from 2000 to 1333), a significant enhancement (42% ) in the radiative power of the micro-combustor is observed (for 35 W thermal power). The combustor with an <span><math><mrow><mi>S</mi><mo>/</mo><mi>V</mi></mrow></math></span> ratio of 1600 consistently showed superior temperature uniformity at all power levels, with the flame stabilizing at step 2 for all the input power levels investigated here. The results will enable scaling up micro-combustor designs that can support higher input thermal power, enhance energy conversion efficiency, and minimize losses.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"328 ","pages":"Article 136328"},"PeriodicalIF":9.0,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068785","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 investigation of surface tension and viscosity on hollow cone spray atomization due to ethanol blending","authors":"Shaikh Abdullah ,&nbsp;Vishnu Bhadran ,&nbsp;Afshin Goharzadeh ,&nbsp;Hamid Ait Abderrahmane ,&nbsp;Dimitrios C. Kyritsis ,&nbsp;Lyes Khezzar ,&nbsp;Constantine D. Rakopoulos ,&nbsp;Dimitrios C. Rakopoulos","doi":"10.1016/j.energy.2025.136507","DOIUrl":"10.1016/j.energy.2025.136507","url":null,"abstract":"<div><div>This paper explores the atomization of ethanol-containing solutions with varying properties. Mixtures of ethanol and deionized (DI) water with different ethanol concentrations (10 %, 20 %, and 50 %) were atomized, along with DI water mixed with 2.5 % surfactant. The droplet size and velocity distribution within the swirling hollow cone spray were analyzed using a Phase Doppler Particle Analyzer (PDPA). The study emphasizes the significant role of viscous, inertial, and surface tension forces in the atomization of the tested mixtures. The trends of the droplets' Sauter Mean Diameter (SMD) along the spray axis were measured and validated with previous experimental results. The results show that mixtures with lower surface tension produce finer and faster droplets, while those with higher viscosity result in larger and slower droplets. When inertial forces are dominant and the surface tension is relatively low, finer spray breakup occurs; conversely, larger droplets form during the spray breakup when viscous forces are more prominent. For the 10 %-ethanol mixture, viscous, inertial, and surface tension forces appear to be in an optimal balance, leading to the formation of fine droplets with only a slight tendency for coalescence downstream. When viscous forces prevail, coalescence occurs in the downstream areas of the spray.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"328 ","pages":"Article 136507"},"PeriodicalIF":9.0,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937113","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":"Enhancing parameter prediction in gas-fired boiler systems through node similarity-based feature aggregation","authors":"Guolin Xiao ,&nbsp;Qi Lang ,&nbsp;Xiaori Gao ,&nbsp;Wei Lu ,&nbsp;Xiaodong Liu","doi":"10.1016/j.energy.2025.136333","DOIUrl":"10.1016/j.energy.2025.136333","url":null,"abstract":"<div><div>Accurate sensor network prediction is crucial for improving industrial boiler efficiency and safety. While existing predictive models show promise, they are constrained by several limitations: (i) insufficient integration of interpretable multi-level spatiotemporal information, (ii) over-reliance on static topologies and shallow features, and (iii) limited continuity and adaptability in complex environments. To address these challenges, we propose a novel framework to improve parameter prediction in gas-fired boiler systems through node similarity-based feature aggregation. First, we apply a node similarity-based multi-level aggregation strategy for interpretable multi-scale integration. Next, dynamic graph learning, utilizing a higher-order graph convolutional network, captures the evolving relationships between sensors and time steps. Additionally, continuous modeling is facilitated by a spatiotemporal ordinary differential equation solver, which overcomes the limitations of discretized time steps. Real-world evaluations show our approach improves accuracy and robustness, even with sensor failures. Furthermore, the continuous model supports predictions at any time step. This approach provides a foundation for data-driven parameter prediction and the modeling of interacting industrial components.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"328 ","pages":"Article 136333"},"PeriodicalIF":9.0,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942926","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":"Multi-objective optimization of a hybrid PVT assisted ground source and air source heat pump system for large space buildings using transient metamodel","authors":"Naihua Yue ,&nbsp;Lingling Li ,&nbsp;Congbao Xu","doi":"10.1016/j.energy.2025.136473","DOIUrl":"10.1016/j.energy.2025.136473","url":null,"abstract":"<div><div>The ground source heat pump (GSHP) system is widely employed as a clean, efficient and economical renewable energy technology for HVAC and hot water supply. In cold zone of China, however, the building heating load is much larger than that of cooling load, which may cause significant soil temperature drop and GSHP performance deterioration. To solve this problem, a novel PVT assisted GSHP and ASHP system (PVT-GA) for gymnasium was proposed in this research. Using transient FEDformer as metamodel, NSGAII was employed for multi-objective optimization of grid power consumption, CO₂ emission, and LCC. Six systems with different configuration were compared. Results show that the optimal PVT-GA system has best performance. Compared with the original system, it reduces the grid power requirement by 70.80 %, CO₂ emission by 70.53 %, and LCC by 54.57 %. The system also could improve the PV array power generated efficiency by 14.81 %. Furthermore, the average soil temperature of PVT-GA system could stable at 15.88 °C, and the COP of GSHP and whole system also could keep stable at a high level with 5.365 kW/kW and 6.296 kW/kW. This research offers a solution to soil thermal imbalance problem in GSHP system and efficiency attenuation issue of PV caused by overheating.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"328 ","pages":"Article 136473"},"PeriodicalIF":9.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942722","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":"Quantitative analysis and operation strategies for daily-regulation hydropower plants impacted by upstream plant","authors":"Junhao Zhang,&nbsp;Yimin Wang,&nbsp;Xuebin Wang,&nbsp;Aijun Guo,&nbsp;Jianxia Chang,&nbsp;Chen Niu,&nbsp;Zhehao Li,&nbsp;Liyuan Wang,&nbsp;Chengqing Ren","doi":"10.1016/j.energy.2025.136526","DOIUrl":"10.1016/j.energy.2025.136526","url":null,"abstract":"<div><div>Hydropower has rapidly developed as a clean, efficient peaking power source, yet upstream hydropower operations significantly affect downstream inflows, especially for daily-regulated plants with limited reservoir capacity. This necessitates adjustments in their operational strategies. To address this, a research framework is proposed to quantify the impact of upstream operations on daily-regulated plants and develop suitable strategies. Firstly, a flow routing model has been established that is capable of simulating both dynamic wave and diffusion wave propagation in unsteady flow conditions along the river channel. Next, a two-stage short-term peak shaving model is developed that integrates the flow routing model with the peak-shaving operations of hydropower plants. The model incorporates an innovative dynamic control strategy for managing water levels at the start and end of the scheduling period. Finally, the Alpha shapes algorithm is employed to extract operational strategies for daily-regulated hydropower plants. The research conclusions are as follows: (1) New upstream plants can shorten flow routing times between existing cascades; (2) Coordinating peaking times reduces water level fluctuations and boosts downstream power generation; (3) Excessive discharge from upstream plants can limit downstream generation; (4) Tailored peak shaving strategies are essential to adapt downstream operations to upstream impacts.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"328 ","pages":"Article 136526"},"PeriodicalIF":9.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947886","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":"Design and evaluation of an integrated CCHP system based on solar thermal supplementary heating and off-peak electrical thermal storage heating","authors":"Jiarui Zeng ,&nbsp;Shaowu Yin ,&nbsp;Lige Tong ,&nbsp;Chuanping Liu ,&nbsp;Li Wang ,&nbsp;Chuan-Yu Wu","doi":"10.1016/j.energy.2025.136505","DOIUrl":"10.1016/j.energy.2025.136505","url":null,"abstract":"<div><div>Rising demands for heating and cooling, along with the need for grid peak regulation, pose challenges to modern energy systems. Traditional methods such as Combined Cooling, Heating, and Power (CCHP), off-peak thermal storage, and ammonia-water absorption cooling often operate in isolation, making them insufficient to meet the growing demand. Thus, this study introduces an integrated CCHP system that utilizes solar energy and off-peak electricity to enhance grid stability. A case study of a 1000 m² office building evaluates turbine and generator steam inlet parameters through sensitivity analyses and multi-objective optimization. The evaluation indicates that, in summer, the system achieves a Coefficient of Performance (COP) of 0.75, with exergy efficiency of 44.74 % and system efficiency of 52.63 %. In winter, the exergy efficiency reaches 63.99 %, and the system efficiency is 82.79 %. The system effectively manages 352.12 kW in summer and 269 kW in winter, saving $23,600 annually in operation and maintenance costs. Additionally, it achieves a Levelized Cost of Storage (LCOS) of $0.17/kWh, surpassing coal-fired and reference CCHP systems in system efficiency.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"328 ","pages":"Article 136505"},"PeriodicalIF":9.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937173","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":"Assessment of steam turbine performance degradation in long-term operation","authors":"Ion Dosa ,&nbsp;Dan Codrut Petrilean ,&nbsp;Andreea Cristina Tataru ,&nbsp;Gabriel Dragos Vasilescu ,&nbsp;Nelu Mija ,&nbsp;Alin Marian Cazac ,&nbsp;Oana Rusu ,&nbsp;Anca-Cristina Tatarcan ,&nbsp;Costica Bejinariu","doi":"10.1016/j.energy.2025.136491","DOIUrl":"10.1016/j.energy.2025.136491","url":null,"abstract":"<div><div>Sustainable Development Goal 7 is about affordable and clean energy for all. The push for decarbonization, with most countries aiming to reach net zero by 2050, will lead to the decommission-ing of many fossil fuel power plants. These plants are complex and costly to build, making repurposing a viable alternative. As a result, studies are exploring ways to convert them to operate on alternative fuels. The steam turbine is one of the most expensive components in a power plant. Over time, prolonged operation can lead to a decline in its efficiency. In order to be used further, the extent of efficiency loss must be assessed, which represents the purpose of the study. The results indicate that power loss ranges from 2.03 % for the 210 MW turbine to 7.51 % for the 150 MW turbine. The analysis of isentropic efficiency of the high pressure, reheat and low-pressure turbine revealed that actual working conditions have an important impact on overall efficiency and pow-er output of the turbine, maybe even more than long-term operation. The power loss can be considered moderate, and anytime it is technically possible, repurposing the steam turbine should be taken into account.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"327 ","pages":"Article 136491"},"PeriodicalIF":9.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927906","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":"Unleashing the power of Energy Saving and Emission Reduction Fiscal Policy: Balancing urban ecological resilience and efficiency","authors":"Zixuan Yang,&nbsp;Huang Yu","doi":"10.1016/j.energy.2025.136478","DOIUrl":"10.1016/j.energy.2025.136478","url":null,"abstract":"<div><div>This study evaluates the impact of green fiscal policies on the coupling coordination of urban ecological resilience and ecological efficiency. The research results indicate that: (1) Green fiscal policies significantly enhance the coupling coordination level of ecological resilience and ecological efficiency in demonstration cities. (2) Mechanism analysis shows that the role of green fiscal policy in coupling and coordinating urban ecological resilience and efficiency is mainly achieved through optimizing industrial carbon emission structure and enhancing green technology innovation. (3) Heterogeneity analysis shows that the impact of green fiscal policies on the coupling coordination of urban ecological resilience and ecological efficiency varies significantly among cities with different geographical locations, cultural industry development levels, and digital infrastructure conditions. (4) Further analysis reveals that the smaller the financial pressure on local governments, the more significant the impact of green fiscal policy on the coupling coordination of urban ecological resilience and ecological efficiency.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"327 ","pages":"Article 136478"},"PeriodicalIF":9.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931554","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 water transport in gas diffusion layer of PEMFC considering the phase-change-induced flow","authors":"Yiming Xu ,&nbsp;Yun Zhang ,&nbsp;Lele Zhang ,&nbsp;Ruijia Fan ,&nbsp;Zhifeng Xia ,&nbsp;Aikun Tang ,&nbsp;Jieqing Zheng","doi":"10.1016/j.energy.2025.136534","DOIUrl":"10.1016/j.energy.2025.136534","url":null,"abstract":"<div><div>The phase-change-induced (PCI) flow triggered by the non-isothermal effect complicates the water transport process in the gas diffusion layer (GDL). So far, studies on the PCI flow in GDL are still scarce. Particularly, the correlation between the PCI flow and the dynamic liquid water behaviors on the GDL surface needs to be further revealed. In this study, an ex-situ visualization setup was developed to investigate the water transport behaviors of the GDL with varied temperatures. The results indicate that low-temperature conditions (&lt;40 °C) are beneficial for the stable liquid water transport, and liquid water breaks through at a specific main emerging position (MEP). However, elevating the temperature to 60 °C increases the condensation droplets and causes the “incubation period”, resulting in the MEP no longer being fixed. Besides, an increase of temperature difference (TD) across the GDL also leads to more water emerging positions on the GDL surface. Compared with the isothermal case, the “incubation period” in the non-isothermal condition lengthens. The PCI flow could also facilitate effective heat removal at high temperatures. This work aims to offer valuable references for understanding the role of PCI flow in the water and thermal management of PEMFC.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"328 ","pages":"Article 136534"},"PeriodicalIF":9.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942924","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 phase-synchronized triboelectric-assisted electromagnetic energy harvesting system for omnidirectional low-frequency wave energy","authors":"Jiaheng Pan ,&nbsp;Yanwei Sun ,&nbsp;Qichao Sun ,&nbsp;Shengyao Jia ,&nbsp;Xiudeng Wang ,&nbsp;Huakang Xia ,&nbsp;Qing Li ,&nbsp;Yinshui Xia ,&nbsp;Ge Shi","doi":"10.1016/j.energy.2025.136529","DOIUrl":"10.1016/j.energy.2025.136529","url":null,"abstract":"<div><div>Wave energy is an essential component of clean energy and an excellent choice for powering ocean sensors. However, the inherent challenges posed by the low-frequency and multi-directional characteristics of waves limit the effective collection and utilization of wave energy. In this study, we propose a novel solution: a multi-directional, triboelectric-assisted electromagnetic generator driven by an eccentric rod rotation. A motion equation of the eccentric rod rotation under regular wave action was established using an ideal wave model as input. The employed eccentric pendulum is highly sensitive to multi-directional, low-frequency external wave excitations. The gear-driven mechanism ensures synchronized output in both frequency and phase domains. This synchronized characteristic is strategically leveraged to incorporate triboelectric energy as an auxiliary power source, thereby enhancing the system's overall electromagnetic energy conversion efficiency. The experimental results demonstrate that under excitation frequencies within 1 Hz, this multi-source collaborative harvesting device achieves up to 50 % higher output power compared to single electromagnetic energy rectification systems. At the same time, the device can output a maximum of 195 mW DC energy at 1Hz excitation frequency. In addition, the study validated the robust performance of the device in simulated wave environments using a commercial module. This new idea provides a new energy harvesting strategy for ocean sensors.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"328 ","pages":"Article 136529"},"PeriodicalIF":9.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072597","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}