Energy Conversion and Management-X最新文献

{"title":"Experimental investigation of the ignition dynamics in a premixed annular combustor using a pre-chamber ignition system","authors":"","doi":"10.1016/j.ecmx.2024.100754","DOIUrl":"10.1016/j.ecmx.2024.100754","url":null,"abstract":"<div><div>In this paper, the ignition characteristics in a MICCA-type annular combustor are studied for the first time using a pre-chamber combustion (PCC) system. The PCC is proposed to replace the traditional spark electrode ignitor in the annular combustor, aiming to shorten ignition time and prevent misfiring. The PCC system is commonly utilized to initiate the ignition process in internal combustion (IC) engines by generating high-temperature turbulent jets that ignite the fuel/air mixture in the main combustion chamber (MCC). The PCC is integrated into a premixed annular combustor consists of sixteen swirling burners. The ignition characteristics and flame propagation patterns are investigated using a high-speed camera under varying conditions of equivalence ratios, bulk velocities, and thermal power levels. Experimental results demonstrate that the PCC exhibits a high ignition response without misfire. The induced turbulent jet from the PCC is observed to propagate into both sides of the annular combustor with high energy, creating a significant initial flame area along the jet trajectory. This enhances the ignition probability compared to traditional spark electrode ignition systems. Due to the higher burning rate resulting from the jet ignition, the light-round time is reduced by 41 % compared to traditional spark electrode ignition systems operating at the same equivalence ratio of 0.81 and the same bulk velocity of 3.22 m/s. This improvement is particularly advantageous for high-altitude re-ignition scenarios.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The cost of green: Analyzing the economic feasibility of hydrogen production from offshore wind power","authors":"","doi":"10.1016/j.ecmx.2024.100770","DOIUrl":"10.1016/j.ecmx.2024.100770","url":null,"abstract":"<div><div>Wind energy is a cornerstone for enhancing grid stability and augmenting energy storage solutions, especially through its synergy with green hydrogen production. While substantial research has analyzed the economic dynamics of offshore wind and green hydrogen, the impact of offshore distances on hydrogen production costs remains underexplored. This study introduces a novel, globally applicable modeling framework for the Levelized Cost of Hydrogen (LCOH), illustrated using the strategically significant Taiwan Strait as a case study. By employing net present value analysis, we compare centralized, distributed, and onshore hydrogen production scenarios, documenting the lowest current LCOH values at $10.27, $10.31, and $11.32 per kg of hydrogen respectively. These findings highlight the cost-effectiveness of the centralized configuration and emphasize the significant costs linked to transmission infrastructure in onshore setups. Looking ahead to 2035, our framework predicts substantial reductions in LCOH, with low-cost scenarios forecasting profitability at just $9 per kilogram of hydrogen. Powered by the universally accessible ERA5 reanalysis dataset, our approach supports analogous assessments worldwide, thereby aiding strategic planning and the deployment of renewable technologies. In-depth sensitivity and Monte Carlo analyses further enhance our understanding of the impacts of offshore distance and other key factors, bolstering the economic evaluation of green hydrogen production. This comprehensive methodology not only assesses present capabilities but also facilitates broad application, fostering the strategic development of renewable technologies globally.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aircraft performance of a novel SAF: Lower costs, lower environmental impact, and higher aircraft performance","authors":"","doi":"10.1016/j.ecmx.2024.100739","DOIUrl":"10.1016/j.ecmx.2024.100739","url":null,"abstract":"<div><div>Investing in Sustainable Aviation Fuel (SAF) is crucial for reducing the aviation industry’s carbon footprint and mitigating climate change. As global air travel demand increases, SAF offers a viable solution to significantly lower greenhouse gas emissions and enhance energy security, ensuring a more sustainable future for aviation. Additionally, converting biomass, particularly waste materials, into SAF adds value by turning potential environmental liabilities into valuable energy resources, promoting a circular economy and reducing overall waste. This study evaluates the aircraft performance of a novel sustainable aviation fuel (SAF) derived from multiple feedstocks in a hybrid biorefinery. SAF performance is compared to two conventional jet fuels, specifically a blend of 30% kerosene and 70% gasoline and JET-A1. The results demonstrated that the optimal SAF outperformed conventional fuels in terms of both thrust and range. Specifically, SAF exhibited a 17% increase in thrust and a 10% increase in range compared to conventional Jet A1 fuel. This novel fuel did not only mitigate CO₂ emissions and achieve a cost reduction of 0.13 to 8.08%, but also exhibited superior aircraft performance. In addition, this fuel also meets the criteria of a “drop-in fuel” as it does not necessitate significant alterations to the currently existing CFM56-7B turbofan engine. This is due to its similar key thermodynamic indicators, such as heat capacities and combustion temperature, which are comparable to those of conventional jet fuels. In addition, this paper identifies the sensitivity of the CFM56–7B turbofan engine fuelled by the novel fuel.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time of the week AutoRegressive eXogenous (TOW-ARX) model to predict thermal consumption in a large commercial mall","authors":"","doi":"10.1016/j.ecmx.2024.100777","DOIUrl":"10.1016/j.ecmx.2024.100777","url":null,"abstract":"<div><div>This paper proposes a procedure to build a Time of the Week AutoRegressive eXogenous (TOW-ARX) model, indexed with respect to time and day of the week, to characterize heat consumption in tertiary buildings. Models for building heat load characterization and prediction are crucial to enhance energy efficiency. The proposed model can be used for different purposes, e.g., control of indoor climate, or characterization of the thermal response of the building. A case study is described where the TOW-ARX model is used to characterize the energy consumption of a large retail building in Madrid. In order to discard the risk of model overfitting, cross validation is applied using the k-fold technique. The performance of the TOW-ARX model is compared with a set of different models: a reduced version of the model where similar segments are clustered using the k-means method (R-TOW-ARX), a general ARX model, a linear regression steady-state TOW model (TOW-LR), a version of the latter reduced through clustering (R-TOW-LR), and a general multiple linear regression model (LR). The results reveal that ARX-based models notably outperforms the rest. The TOW-ARX model shows the best metrics, but also outnumbers the number of coefficients of the other models by far. The selection of the most suitable model is not straightforward and should depend on the purpose of such model: the TOW-ARX model would arguably be the best for control purposes due to its low mean absolute error, but the ARX model would be preferable for an efficient characterization of the thermal response of a building due to its reduced number of parameters.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Torque ripple reduction and increasing of torque per volume for hybrid electrical vehicle","authors":"","doi":"10.1016/j.ecmx.2024.100758","DOIUrl":"10.1016/j.ecmx.2024.100758","url":null,"abstract":"<div><div>Hybrid electrical vehicles (HEV) should be designed somehow torque is smooth. Because torque ripple not only reduces control precision but also increases elements vibration that causes acoustic noise, mechanical instability and early aging parts. Furthermore, torque per volume should be maximized and heat removal should be accomplished without torque weakening. It is proposed the volume and internal dimensions are determined due to the thermal considerations and maximize torque per volume. The mentioned application is neglected heat removal so volume is constant. Therefore, HEV is manufactured by two objective functions: either minimum fluctuations or maximum average torque. In this paper series hybrid excitation synchronous machine (SHESM) is utilized as HEV. Two-objective optimization problems are solved by MOEA/D, NSGA II, PESA II and SPEA II algorithms based on a two-dimensional (2-D) model. The performance indices of optimal structure are evaluated by 2-D and confirmed by numerical method.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developing an energy audit methodology for assessing decarbonization potential in high performance buildings","authors":"","doi":"10.1016/j.ecmx.2024.100765","DOIUrl":"10.1016/j.ecmx.2024.100765","url":null,"abstract":"<div><div>High-performance buildings (HPBs) are designed to minimize environmental impacts during operation, but ensuring continuous efficiency improvements remains a challenge. Existing energy audit methodologies have been developed with limited support of precise operational data. However, the advent of Building Energy Management Systems (BEMS) and the establishment of de facto industry standards for building service and space usage have enabled energy audits to be conducted at an unprecedented level of detail. Taking advantage of these developments, this study proposes an original integrated approach for HPB by combining a standard energy audit framework with BEMS data. The novel method conducts: (1) detailed energy and water consumption profiling across multiple timescales; (2) benchmarking using data envelopment analysis against other HPBs; (3) building diagnostics to identify further carbon reduction opportunities; and (4) marginal abatement cost analysis to explore economically feasible improvement measures for owners. When specifically applied to an HPB in Tokyo, the findings reveal substantial room for further improvements. At least 10.1% in energy saving potential exists compared to the building’s design performance. Moreover, implementing selected cost-effective measures could economically achieve an 8.9% reduction in CO2 emissions. This multifaceted study makes three key original contributions. First, it develops a systematic energy audit methodology tailored to BEMS-equipped HPBs, enabling granular, spatiotemporal analysis of resource consumption. Second, it extends this framework beyond energy to holistically encompass water consumption. Third, it provides quantitative evidence that even highly-rated HPBs may still have significant remaining potential for operational environmental impact reductions, which can be identified in detail through the proposed approach. Overall, by harnessing BEMS data and industry standards, this research demonstrates a feasible and cost-effective pathway for HPB owners and operators to continuously optimize resource efficiency. As the urgency of climate action intensifies, this innovative approach offers a crucial toolkit for the building sector to enhance its contribution to global sustainability goals.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electric vehicles: Battery technologies, charging standards, AI communications, challenges, and future directions","authors":"","doi":"10.1016/j.ecmx.2024.100751","DOIUrl":"10.1016/j.ecmx.2024.100751","url":null,"abstract":"<div><div>Electric vehicles (EVs) have gained significant attention in recent years due to their potential to reduce greenhouse gas emissions and improve energy efficiency. An EV’s main source of power is its battery, which plays a crucial role in determining the vehicle’s overall performance and sustainability. The purpose of this paper is to examine the advancements in battery technology associated with EVs and the various charging standards applicable to EVs. Additionally, the most common types of automotive batteries are described and compared. Moreover, the application of artificial intelligence (AI) in EVs has been discussed. Finally, the challenges associated with EV battery development, as well as suggestions for improvement, are discussed. According to the study, Lithium-ion batteries are the most common in EVs due to their high energy density, long lifespan, and cost-effectiveness, despite their temperature sensitivity. Other battery types, like lead-acid and nickel-based, vary in efficiency, but are less commonly used in modern EVs. Solid-state batteries are seen as the future for their higher energy density and faster charging, though they face challenges like flammability. Wireless charging technology, still in development, promises superior convenience and sustainability than traditional methods. AI improves EV performance through enhanced battery management, autonomous driving, vehicle-to-grid communication, etc. Overcoming challenges like battery recycling, metal scarcity, and charging infrastructure will be crucial for the widespread adoption of EVs. This will be supported by government policies and battery technology innovations.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Green and Blue Hydrogen Production Potential in Saudi Arabia","authors":"","doi":"10.1016/j.ecmx.2024.100742","DOIUrl":"10.1016/j.ecmx.2024.100742","url":null,"abstract":"<div><div>The Kingdom of Saudi Arabia has rich renewable energy resources, specifically wind and solar in addition to geothermal beside massive natural gas reserves. This paper investigates the potential of both green and blue hydrogen production for five selected cities in Saudi Arabia. To accomplish the said objective, a techno-economic model is formulated. Four renewable energy scenarios are evaluated for a total of 1.9 GW installed capacity to reveal the best scenario of Green Hydrogen Production (GHP) in each city. Also, Blue Hydrogen Production (BHP) is investigated for two cases of Steam Methane Reforming (SMR) with different percentages of carbon capture. The two BHP scenarios were compared with a base case scenario of hydrogen production from natural gas without CCS/U (gray hydrogen). The economic analysis for both GHP and BHP is performed by calculating the Levelized Cost of Hydrogen (LCOH) and cash flow. The LCOH for GHP range for all cities ($3.27/kg–$12.17/kg)₎ with the lowest LCOH is found for NEOM city (50% PV and 50% wind) ($3.27/kg). LCOH for the three SMR cases are $0.534/kg, $0.647/kg, and $0.897/kg for SMR wo CCS/U, SMR 55% CCS/U, and SMR 90% CCS/U respectively.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrothermal liquefaction of southern yellow pine with downstream processing for improved fuel grade chemicals production","authors":"","doi":"10.1016/j.ecmx.2024.100735","DOIUrl":"10.1016/j.ecmx.2024.100735","url":null,"abstract":"<div><div>The hydrothermal liquefaction (HTL) technique for liquefying lignocellulose biomass feedstock is often associated with low biocrude yield and poor fuel properties. This study examined the HTL of southern yellow pine sawdust and the hydrotreatment (HYD) of produced biocrudes in an effort to address these challenges. Pine HTL treatment was performed within water and water–ethanol mixed reaction medium at 250, 300, and 350℃ temperatures using metallic iron (Fe) as a catalyst. The rising reaction temperature in a water medium and increasing ethanol content in a mixed reaction medium were found to be effective in enhancing the biocrude yield from the non-catalytic pine HTL process. Maximum non-catalytic biocrude yield of 18 wt.% was produced in water at 350℃, whereas the ethanol and water (1:1 on mass basis) mixture generated the highest biocrude yield of 34 wt.% at 300℃ without any catalyst. The iron catalyst facilitated a maximum of 29 wt.% of biocrude yield as opposed to 18 wt.% without the catalyst at 350℃ in water. The use of an iron catalyst also raised the calorific value of produced biocrudes by 2.5–14 % within 250-350℃ in both water and water–ethanol media. The catalytic and non-catalytic biocrude products were chosen to undergo HYD treatment at 400 °C under high hydrogen pressure (initial 1000 psi) using an alumina-supported cobalt-molybdenum catalyst. The HYD treatment reduced the oxygen content of upgraded oils by 36–60 % compared to the parent HTL biocrudes with 35–37 MJ/kg calorific values. The simulated distillation detected the maximum gasoline range compounds in upgraded oil from catalyst and water–ethanol conditions, whereas the GC–MS analysis revealed the production of increased aromatic hydrocarbons in all upgraded HYD oils. This work has demonstrated the potential of ethanol and inexpensive iron catalyst in enhancing the biocrude production from pine, which could be upgraded to better fuel using the HYD process.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive analysis of blade geometry effects on Savonius hydrokinetic turbine efficiency: Pathways to clean energy","authors":"","doi":"10.1016/j.ecmx.2024.100762","DOIUrl":"10.1016/j.ecmx.2024.100762","url":null,"abstract":"<div><div>The rising global demand for clean and renewable energy has intensified interest in hydrokinetic energy harvesting, with Savonius turbines gaining attention due to their simplicity and low cost. While numerous studies have focused on refining blade designs for wind turbines, limited research has been conducted on water turbines to identify the best design. This study investigates the effect of blade geometry on the efficiency of Savonius hydrokinetic turbines to identify the optimal configuration. Three new blade designs were tested, incorporating inner blades and varying blade numbers. These designs were experimentally evaluated to identify the optimal turbine configuration for maximum efficiency, and the findings were then validated through numerical studies. Rotational analysis was conducted to investigate torque variations across a full turbine rotation from 0° to 360°, and flow characteristic analysis was performed by utilizing pressure and contour plots at critical positions, including 0°, minimum torque coefficient (C_{T Min}), and maximum torque coefficient (C_{T Max}). Results indicate that the 2-blade Savonius turbine achieved the highest efficiency, with a maximum torque coefficient of 0.29 and a power coefficient of 0.22. It demonstrated 63.5 % greater power efficiency compared to the 3-Blade Savonius Turbine, 2.65 times greater than the Segmented Quarter Savonius Turbine, and 2.26 times greater than the Concentric Arc Savonius Turbine. These findings highlight the importance of blade geometry optimization in improving the performance of Savonius turbines for efficient hydrokinetic energy generation.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}