Energy最新文献

{"title":"Transient dynamic cycle evolution and thermodynamic performance analysis of a free-piston engine generator","authors":"Jiayu Wang,&nbsp;Chang Liu,&nbsp;Huihua Feng,&nbsp;Boru Jia,&nbsp;Zhiyuan Zhang,&nbsp;Yidi Wei","doi":"10.1016/j.energy.2024.133669","DOIUrl":"10.1016/j.energy.2024.133669","url":null,"abstract":"<div><div>The free-piston engine generator (FPEG) is a promising hybrid power system. Eliminating the crankshaft mechanism, it features a variable piston dynamic cycle distinct from traditional engines. This paper investigates transient dynamic evolutions, identifies the stable operation zone, and further analyzes thermodynamic performance under various key design parameters. First, a coupled dynamic-thermodynamic model is developed for FPEG. Second, transient dynamic evolutions from start-up to combustion-generation stage are analyzed. The boundaries of operating parameters are identified to ensure the presence of limit cycles for stable operation. Subsequently, the thermodynamic performance is comprehensively evaluated. The indicated power and thermal efficiency improve as load resistance and excess air ratio decrease. The maximum and minimum performance points consistently occur on the overshooting and damping lines, respectively. A lower piston assembly mass and higher design compression ratio are recommended to achieve higher indicated power and thermal efficiency. A lower stroke-to-bore ratio leads to higher indicated power with a slight decrease in thermal efficiency. Additionally, the load coefficient should be adjusted to ensure stable operation according to the design parameters. This paper enhances the understanding of transient dynamic evolutions of the FPEG and provides guidance for prototype design aimed at achieving stable operation and improved output performance.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133669"},"PeriodicalIF":9.0,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661609","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":"Green technology diffusion mechanism in China's aviation industry cluster based on complex network game model","authors":"Sen Zheng ,&nbsp;Jie Zhang ,&nbsp;Lirong Jian","doi":"10.1016/j.energy.2024.133634","DOIUrl":"10.1016/j.energy.2024.133634","url":null,"abstract":"<div><div>The aviation industry cluster's diverse strategic choices of firms significantly influence the green technology diffusion. To examine how external factors and intra-cluster associative structures influence green technology diffusion, this paper constructs an evolutionary game model of green technology networks based on small-world networks, integrating governmental regulation and public oversight perspectives. Through simulations within the real-world aviation context, we analyze the dynamic characteristics of green technology diffusion. Furthermore, we investigate the driving effects of governmental and public initiatives in facilitating green transformation of aviation manufacturing firms. The empirical results reveal several critical insights: (1) A government-mandated minimum threshold for environmental subsidies is crucial to propel the green technology diffusion. In scenarios where environmental regulation penalties are inadequately low, speculative behaviors among firms occur, hindering the diffusion process. (2) Amplifying public engagement significantly bolsters the rate of green technology diffusion and augments the average returns for firms. The public's tolerance threshold for environmental pollution exhibits a high sensitivity to the success of green technology diffusion. (3) We discern variances in green technology diffusion across different network types. While green technology successfully permeates scale-free networks with diverse densities, its diffusion is notably impeded in small-world networks with lower densities. The associative structures and hierarchical distribution of firms within clusters drive varying outcomes in green technology diffusion.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133634"},"PeriodicalIF":9.0,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661617","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":"How do nuclear energy consumption, environmental taxes, and trade globalization impact ecological footprints? Novel policy insight from nuclear power countries","authors":"Muhammad Yasir Mehboob ,&nbsp;Benjiang Ma ,&nbsp;Muhammad Sadiq ,&nbsp;Muhammad Basit Mehboob","doi":"10.1016/j.energy.2024.133661","DOIUrl":"10.1016/j.energy.2024.133661","url":null,"abstract":"<div><div>Energy systems should grab the opportunity to adopt clean energy sources and technologies to mitigate environmental impacts. This work explores the influence of nuclear energy consumption on reducing the ecological footprint, considering environmental taxes and trade globalization in five nuclear-powered economies from 1990 to 2021. This study employed several econometric models, including the preliminary analysis, the CS-ARDL test for long-run forecasting and the Dumitrescu-Hurlin causality test. The long-run findings revealed that nuclear energy usage and environmental taxes support reducing environmental costs by lowering the ecological footprint. However, trade globalization raises environmental costs by increasing the ecological footprint. Additionally, causality test outcomes show that a one-way causal link exists among nuclear energy and the ecological footprint. The results highlight government actions prioritizing investment in nuclear energy consumption projects and encouraging nuclear energy efficiency to mitigate ecological degradation and lead to a low-carbon future. This viewpoint also encourages policymakers to make well-informed decisions to uphold ecological sustainability.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133661"},"PeriodicalIF":9.0,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661612","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":"Wave energy conversion by multi-mode exciting wave energy converters arrayed around a floating platform","authors":"Yong Cheng ,&nbsp;Weifeng Liu ,&nbsp;Saishuai Dai ,&nbsp;Zhiming Yuan ,&nbsp;Atilla Incecik","doi":"10.1016/j.energy.2024.133621","DOIUrl":"10.1016/j.energy.2024.133621","url":null,"abstract":"<div><div>An array of compact, portable and stable Wave Energy Converters (WECs) integrated with an offshore floating platform can reduce the platform's motion response to waves, and extract wave energy simultaneously through multiple Power Take-Off (PTO) units. This paper proposes an innovative hybrid system composed of a cylindrical free-floating platform and four point-absorber type WECs hinged at the external structure of the cylindrical platform. The relative motions between a WEC and the platform drive a PTO-system, and thus desirable wave energy conversion is achieved from combining multiple WECs with multi-mode motions constructively. To confirm feasibility and hydrodynamics performance of the proposed concept, multi-body computational models for different scenarios are developed. The wave focusing toward WECs are realized by the array reflection, while the presence of near-trapping waves amplifies energy dissipation. The seaward and leeward WECs are more sensitive on the array interval than those lateral WECs. Additionally, shallower and deeper submergences are preferred for WECs, respectively, resulting into multi-body resonances across a broadband wave period. For the discrete PTO system, different optimized damping coefficients are recommended to guarantee the high energy absorption regardless of wave periods. The present WEC-platform system can harvest wave energy in an omnidirectional manner.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133621"},"PeriodicalIF":9.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661717","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":"Power increase potential of coal-fired power plant assisted by the heat release of the thermal energy storage system: Restrictions and thermodynamic performance","authors":"Lin Miao,&nbsp;Hui Yan,&nbsp;Ming Liu","doi":"10.1016/j.energy.2024.133509","DOIUrl":"10.1016/j.energy.2024.133509","url":null,"abstract":"<div><div>The integration of a thermal energy storage (TES) system is an effective way to improve the load cycling rate of coal-fired power plants (CFPPs). To evaluate the power increase potential and thermodynamic performance of CFPP supplied by heat release of the molten salt TES system, eight discharging modes for CFPP integrated with the TES system including steam injection, heater bypass, and additional turbine schemes were comparatively evaluated. The system simulation models of the integrated systems were developed and the thermodynamic performance of the proposed system were evaluated. Results show that the mode SI-HPT (high-pressure turbine steam injection) has the largest output power increase of 25.00 % under the benchmark condition of 75%THA, but the mode HB-LPH (low-pressure heater bypass) shows a very low output power increase of 2.08 %. Moreover, the power generation efficiency is changed by the external heat source through a change in the average heat absorption temperature of the Rankine cycle and the internal irreversibility of the steam/water cycle. Under the typical benchmark discharging condition of 75%THA, the power generation efficiency of the turbine in mode SI-LPT (low-pressure turbine steam injection) can be reduced from 47.41 % to 44.15 %, but it can be increased from 47.41 % to 48.86 % in mode SI-HPT. When the temperature ranges of the TES system are above 600 °C and below 450 °C, the modes SI-HPT and SI-LPT obtain the optimal comprehensive performance, respectively. This study can provide the scientific guidance for retrofit for CFPP to achieve efficient and flexible design.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"312 ","pages":"Article 133509"},"PeriodicalIF":9.0,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529535","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":"Understanding the zero-emission vehicle market spatial diffusion and its determinants from 2019 to 2022 using spatial econometric models","authors":"Hui Shi,&nbsp;Konstadinos G. Goulias","doi":"10.1016/j.energy.2024.133607","DOIUrl":"10.1016/j.energy.2024.133607","url":null,"abstract":"<div><div>Due to the rapid rise in the acceptance of zero-emission vehicles (ZEVs), much research has been conducted on the market evolution of alternative fuel technology. The research reported in this paper builds on prior studies by incorporating several new directions. Firstly, the spatial distribution of ZEV purchases in California is explored, then seven models (two nonspatial models and five spatially explicit models) are developed to predict regional ZEV sales. The predictions are based on fundamental and widely accessible characteristics such as infrastructure and demographic statistics. Next, a spatial econometric model known as the “spatial error model” is chosen to distribute ZEV sales from their original postal code (ZIP) level to the more often utilized US census tract level. This allows for carrying out a comprehensive analysis that includes studying the correlation of ZEV sales with local incentives and disadvantaged communities. Results reveal that ZEV sales in California increased significantly between 2019 and 2022, as spatial autocorrelation decreased. Vulnerable groups were less likely to have access to ZEVs, particularly during the initial stage of the ZEV market penetration in 2019. As expected, regions with considerable ZEV sales tended to also experience substantial purchase rebates and lower disadvantaged population, especially in 2019.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133607"},"PeriodicalIF":9.0,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661665","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}

{"title":"Revealing the essential and sufficient conditions for the energy consumption diversification","authors":"Emad Kazemzadeh ,&nbsp;José Alberto Fuinhas ,&nbsp;Narges Salehnia ,&nbsp;Nuno Silva ,&nbsp;Magdalena Radulescu","doi":"10.1016/j.energy.2024.133601","DOIUrl":"10.1016/j.energy.2024.133601","url":null,"abstract":"<div><div>To investigate the diversification of energy consumption in 65 countries during 2019, this study utilizes the Shannon-Wiener index (SWI), Necessary Condition Analysis (NCA), and Fuzzy Set Qualitative Comparative Analysis (FsQCA). According to the NCA model, all variables, except FSI, have the necessary conditions for the energy consumption diversification (ECD). The fsQCA model for high ECD identifies four adequate configurations that involve a combination of high human development, high green growth, global innovation, and either lower levels of urbanization or the presence of fragile states. One notable solution, with a consistency score of 93 %, is that a higher level of global innovation combined with lower levels of urbanization leads to higher ECD. Conversely, the model identifies three configurations sufficient for low ECD, which typically include higher levels of urbanization, fragile states, and lower levels of innovation and green growth. One of the most significant of these, with a consistency score of 81 %, is that increasing urbanization while decreasing green growth and global innovation leads to low ECD. According to the research findings, policymakers should strengthen the innovation ecosystem and focus on developing human capital to enhance energy diversity. Additionally, efforts should be made to combat corruption, stabilize governance, and improve oversight to ensure greater investment in clean energy.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133601"},"PeriodicalIF":9.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661670","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":"Flexibility enhancement of combined heat and power unit integrated with source and grid-side thermal energy storage","authors":"Chengxu Chen ,&nbsp;Xiaoze Du ,&nbsp;Lizhong Yang ,&nbsp;Alessandro Romagnoli","doi":"10.1016/j.energy.2024.133568","DOIUrl":"10.1016/j.energy.2024.133568","url":null,"abstract":"<div><div>The potential of improvement of both overall energy efficiency and penetration of renewable energy for the combined heat and power (CHP) unit was investigated by integrating the source-side and grid-side thermal energy storage (TES) systems simultaneously. The mathematical model of the proposed thermal system was established, with which the flexibility-enhancing features across diverse operating conditions were analyzed. The flexibility improvement rate, heat consumption rate, TES cycle efficiency and energy efficiency were revealed. Moreover, the wind power consumption, coal-savings and net annual revenue of CHP unit integrated with different TES were presented. The results indicated that the flexibility improvement rate of source-side TES, grid-side TES and dual TES is 2.4 %, 21.2 % and 26.2 %, respectively. The heat consumption rate of a CHP unit integrated with source-side TES system is lower compared to that of a traditional CHP unit when power load ratio is below 50 %. The CHP unit integrated with a dual TES system exhibited a maximum increase in wind power accommodation rate of 37.7 % and a maximum reduction in standard coal consumption of 7.7 %. The proposed systems offer a promising approach for enhancing the flexibility of CHP units to accommodate more renewable energy.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"312 ","pages":"Article 133568"},"PeriodicalIF":9.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530162","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":"Artificial intelligence application for assessment/optimization of a cost-efficient energy system: Double-flash geothermal scheme tailored combined heat/power plant","authors":"Xuetao Li ,&nbsp;Azher M. Abed ,&nbsp;Mohamed Shaban ,&nbsp;Luan Thanh Le ,&nbsp;Xiao Zhou ,&nbsp;Sherzod Abdullaev ,&nbsp;Fahad M. Alhomayani ,&nbsp;Yasser Elmasry ,&nbsp;Ibrahim Mahariq ,&nbsp;Abdul Rahman Afzal","doi":"10.1016/j.energy.2024.133594","DOIUrl":"10.1016/j.energy.2024.133594","url":null,"abstract":"<div><div>Utilizing the capabilities of artificial intelligence can lead to the development of energy systems and power supply chain that are more efficient, sustainable, and resilient. The integration of machine learning techniques within these systems provides substantial benefits and is essential for enhancing overall performance. As the global community confronts challenges like climate change and rising energy demands, machine learning will play an increasingly vital role in defining the future of energy systems. This research examines how effective regression-based machine learning techniques are for analyzing and optimizing the performance of a geothermal combined heat and power system. It focuses on creating both linear and quadratic models to assess electricity generation, heat production, and the efficiency of the entire system. The evaluation of these models is performed through residual analysis and R-squared statistics. Results indicate that quadratic models surpass linear ones, with linear model achieving an R-squared value of 88.56 % for power generation, while the quadratic model reaches an impressive R-squared level of 99.88 %. Furthermore, the study demonstrates that quadratic machine learning models hold significant promise for optimizing system performance, shown by desirability metrics exceeding 0.99. This research highlights the importance of regression-based machine learning methods in analyzing and improving geothermal combined heat and power systems.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133594"},"PeriodicalIF":9.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661711","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":"Assisting denitrification and strengthening combustion by using ammonia/coal binary fuel gasification-combustion: Effects of injecting position and air distribution","authors":"Baochong Cui,&nbsp;Xiaoxiao Wang,&nbsp;Shilin Yu,&nbsp;Kejie Zhang,&nbsp;Yingjie Zhang,&nbsp;Renhui Ruan,&nbsp;Xuebin Wang,&nbsp;Houzhang Tan","doi":"10.1016/j.energy.2024.133609","DOIUrl":"10.1016/j.energy.2024.133609","url":null,"abstract":"<div><div>The direct co-firing of ammonia (NH₃) with coal is an effective approach for reducing carbon emissions from coal-fired plants. However, the limitations of NH₃ combustion, such as its high ignition energy requirement and high NO_<em>x</em> emissions, restrict its large-scale co-combustion in coal-fired units. In this study, a self-sustaining gasification–combustion experimental system was employed, and its denitrification performance and combustion strengthening capability for NH₃/coal binary fuel under different NH₃ injection positions and air distribution methods were evaluated. The results of co-firing 20 % NH₃ in the gasifier revealed that its operating temperature can be flexibly controlled within the optimal reaction temperature window of SNCR by adjusting the primary air ratio (λ₁). Increasing λ₁ was beneficial for NH₃ and coal conversion and denitrification in the gasifier; at λ₁ = 0.53, the conversion rate of NH₃ and N₂ reached 86.37 % and 83.59 %, respectively, with no NO_<em>x</em> being detected at the gasifier outlet. Furthermore, increasing λ₁ promoted the development of gasified char pore structure, thereby improving reactivity. After entering the down-fired combustor (DFC), increasing λ₁ promoted NH₃ and coal burnout and effectively controlled NO_<em>x</em> emissions, reaching a level similar with that of pure coal under λ₁ = 0.53. Co-firing 20 % NH₃ in the DFC also demonstrated that the introduction of inner secondary air was conducive to char burnout, however, increased NH₃ slip. The outer secondary air promoted NH₃ combustion, however, exacerbated NO_<em>x</em> emissions and inhibited gasified char combustion. The uniform air distribution method balanced the combustion of NH₃ and gasified char, and effectively controlled NO_<em>x</em> emissions. When the same air distribution method was used, co-firing NH₃ in the gasifier was more favourable for NO_<em>x</em> control, whereas co-firing NH₃ in the DFC benefited coal burnout. This study provides innovative ideas and serves as a reference for developing enhanced combustion and low NO_<em>x</em> emission technologies for large-scale NH₃ co-firing in coal-fired units.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"312 ","pages":"Article 133609"},"PeriodicalIF":9.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529542","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}