Energy Conversion and Management最新文献

{"title":"Ammonia composite combustion with alcohol/ether: A systematic review from engine applications to combustion enhancement and emission mechanisms","authors":"","doi":"10.1016/j.enconman.2024.119160","DOIUrl":"10.1016/j.enconman.2024.119160","url":null,"abstract":"<div><div>Ammonia, as a zero-carbon fuel and efficient hydrogen carrier, has great potential for decarbonization in engineering applications, transportation and power generation, emerging as a powerful candidate for alternative energy in the context of global carbon neutrality. However, the problems of difficult ignition, slow combustion and poor stability of ammonia limit its application as the pure fuel in energy conversion machinery. Combining ammonia with active alcohol/ether fuels is a feasible solution aimed at improving ammonia combustion characteristics while reducing carbon emissions. This work systematically reviewed the research progress of ammonia composite combustion with various alcohols/ethers, including ammonia with methanol, ethanol, butanol, dimethyl ether, diethyl ether, dimethoxymethane, and polyoxymethylene. This review covers macro-level engine applications, performance and emission characteristics, fundamental combustion characteristics (ignition, flame propagation and species distribution), and micro-level reaction kinetics (combustion enhancement and emission mechanisms). Based on these findings, future directions for further exploration are proposed. Ammonia-alcohol/ether combination fuels can be successfully applied in SI and CI engines through mixed-fuel, dual-fuel, and jet-controlled compound ignition modes. They have shown potential to outperform gasoline/diesel, but their effectiveness is limited by factors such as alcohol/ether type, energy ratio, engine operating conditions, ignition timing, and injection strategy. Ammonia-alcohol/ether typically reduce C-based emissions but increase N-based emissions. Both NO_x emissions, resulting from the competition between fuel-NO_x and thermal-NO_x, and soot emissions, influenced by the competition between increased carbon content and improved combustion, show nonlinear trends with alcohol/ether ratio. At the fundamental combustion level, the addition of alcohol/ether significantly shortens the ignition delay of ammonia, accelerates its burning velocity, and enhances its combustion stability. However, the promotion efficiency shows a nonlinear relationship with the alcohol/ether blending ratio and a considerable dependence on molecular structure, temperature, and pressure. At the kinetics level, the discussion focuses on the key reaction pathways of alcohol/ether enhanced ammonia ignition, the interactions between C-N components leading to promotion, synergy and inhibition mechanisms, and the coupled mechanisms for the formation/inhibition of NOx and soot emissions. The research results of this work contribute to a comprehensive understanding of the key technologies of ammonia-alcohol/ether engines and reaction mechanisms of ammonia composite combustion, providing important theoretical references for achieving the integration of ammonia and alcohol/ether fuels and near zero emissions.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442538","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":"Modeling and multiobjective optimization of a solar-powered reverse osmosis desalination system with hydrogen energy storage","authors":"","doi":"10.1016/j.enconman.2024.119148","DOIUrl":"10.1016/j.enconman.2024.119148","url":null,"abstract":"<div><div>Remote communities often face challenges in accessing clean water, crucial for improving their quality of life and health. To address this issue, this work focuses on optimizing the design of a hybrid renewable energy system, integrating photovoltaic (PV) and hydrogen storage to power a reverse osmosis desalination (ROD) system. A novel multiobjective optimization model, implemented as a mixed-integer linear program, is proposed to minimize exergy losses and annual cycle costs, ensuring optimal system performance. The optimized decision variables include the sizing and power allocation of the hybrid energy system, and the operation of the ROD system based on water demand. Operational characteristics such as energy balance, system capacity, and daily water demand are incorporated into the model as constraints. The flexibility of the model allows for site-specific parameters, tailoring solutions to meet the needs of remote communities. The optimization model is tested in this work for two case studies, revealing significant cost-effectiveness disparities. In the first community, the system achieves a levelized cost of water (LCW) and exergy efficiency of 2.119 USD/m³ and 11.48 % for an 18 m³ daily water demand, compared to 3.757 USD/m³ and 8.79 % for a 3 m³ daily demand in the second community. This highlights the economic viability and higher efficiency of such a system for large-scale applications, achieving up to a 16.11 % lower LCW than other studies. Additionally, it demonstrates the flexibility of the proposed optimization model and provides a comprehensive evaluation of hybrid energy systems for remote communities.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442543","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":"Full-spectrum solar water decomposition for hydrogen production via a concentrating photovoltaic-thermal power generator-solid oxide electrolysis cell system","authors":"","doi":"10.1016/j.enconman.2024.119158","DOIUrl":"10.1016/j.enconman.2024.119158","url":null,"abstract":"<div><div>This study introduces a novel solar-powered concentrating photovoltaic-thermal power generator-solid oxide electrolysis cell system designed to enhance hydrogen production efficiency by optimizing both electrical and thermal energy utilization. The system incorporates a thermal power generator to convert excess high-temperature thermal energy into electrical energy, addressing energy losses associated with high-temperature water electrolysis. Thermodynamic analysis shows that the integration of the thermal power generator improves energy and exergy efficiencies to 0.60 and 0.52, while lowering the optimal operating temperature to 1173 K. The system’s efficiency is sensitive to the proportion of electrical energy supplied by the thermal power generator, with an optimal range identified between 0.1 and 0.2. Higher temperatures improve hydrogen production and efficiency, but increased voltage negatively impacts thermodynamic efficiency. These findings demonstrate that the proposed system offers substantial improvements over conventional solar hydrogen production methods, making it a promising candidate for sustainable hydrogen production. Further research will focus on system integration, material costs, and scalability for commercial use.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442542","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":"Modelling the market diffusion of hydrogen-based steel and basic chemical production in Europe – A site-specific approach","authors":"","doi":"10.1016/j.enconman.2024.119117","DOIUrl":"10.1016/j.enconman.2024.119117","url":null,"abstract":"<div><div>Climate-neutral hydrogen is a promising option to replace fossil fuels and reduce greenhouse gas emissions in energy-intensive industries. At the same time, spatial and timely dynamics of hydrogen market diffusion are uncertain. This study simulates the market diffusion of hydrogen-based production routes for the entire European plant stock of primary steel, high-value chemicals, methanol, and ammonia production sites. The model includes a total of 158 plants at 96 sites and explicitly considers hydrogen infrastructure, plant ages, production capacities and reinvestment cycles. Sixteen scenario sensitivities were defined to analyse various future hydrogen and carbon dioxide price pathways. The results show that one investment opportunity remains until 2050 for all plants, while 36% of plants require reinvestment before 2030. The cost-competitiveness of hydrogen-based production varies across products: Methanol and high-value chemicals can only be competitive with hydrogen prices below 60 €/MWh. For steel, a high carbon dioxide price and natural gas-fired direct reduction can mitigate fossil lock-ins using natural gas as bridging option towards full use of hydrogen. The study highlights the risk of reinvesting in fossil technologies without additional policies. The maximum technical hydrogen demand potential is 1000 TWh, but considering techno-economic limitations in the sensitivities, only 64 to 507 TWh can be reached. The planned future hydrogen network matches most reinvestment needs.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442540","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":"Improving full-chain process synergy of multi-energy complementary distributed energy system in cascade storage and initiative management strategies","authors":"","doi":"10.1016/j.enconman.2024.119120","DOIUrl":"10.1016/j.enconman.2024.119120","url":null,"abstract":"<div><div>Fluctuating renewable energies and loads challenge the wide-spreading of the clean and sustainable multi-energy complementary distributed energy system. This paper aims to improve the adaptiveness of such a system to source-load fluctuations by integrating a cascade storage sub-system and coordinating all controllable energy processes in the production-conversion-storage-consumption of multi-energy flows. Taking the energy system body as the research boundary and neglecting the system’s impact on the external environment, a wind-solar-driven distributed energy system with variable wind-to-heat and wind-to-power modes is created. The proposed system integrates mechanical, electrical, and different grades of thermal energy flows while the cascade storage sub-system softly docks them. Then, all controllable energy technologies in the proposed distributed energy system are reorganized into thirteen combining processes, and a seasonal active multi-energy reserve-based initiative strategy is proposed to coordinate these combining processes to cover all possible renewable source and load distributions hierarchically. Finally, considering economic, environmental, and process synergy, multi-parameter optimization is presented to maximize the match index between the distributed energy system and annual source-load distributions. Simulation results show that the proportion of renewable energy is up to 43.38%. While the prime mover supplements insufficient renewable energy, its waste heat almost meets the remaining thermal loads. The alterable wind-to-heat mode saves energy by 9.59%, and waste heat’s efficiency is improved by 56.69%. The active thermal reserve promotes thermoelectric decoupling and extends the battery’s life by 6.77%. The presented work guides clean, efficient, reliable and integrated multi-energy conversion and utilization in an unstable operating environment.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442541","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":"Effects of variable valve timing and duration on catalyst heating using optically accessible MPI engine","authors":"","doi":"10.1016/j.enconman.2024.119157","DOIUrl":"10.1016/j.enconman.2024.119157","url":null,"abstract":"<div><div>The effects of intake and exhaust valve timing and duration were investigated using an optically accessible multi-point injection engine under catalytic heating conditions. The target engine features a quartz cylinder and an extended piston with a quartz piston crown. To understand the effects of valve timing and duration on the in-cylinder flow, particle image velocimetry (PIV) was applied to visualize the in-cylinder flow. The acquired images were used to quantitatively evaluate the in-cylinder flow characteristics, and the effects of these flow characteristics on the flame propagation were analyzed through flame visualization experiments. The results indicate that when the intake valve timing was advanced by 20°, the average flow velocity was 59.5% higher, the tumble ratio was 72.2% greater, and the flame propagation velocity was also the fastest. The longest duration of 218° was advantageous for the intake valve duration, and the formation of a tumble flow pattern was important for fuel and air mixing. Finally, in the exhaust valve timing and duration experiment, the exhaust valve closing timing affected the amount of residual gas inside the cylinder. Therefore, the ratio of diffusion flames increased when the exhaust valve timing was advanced or retarded compared to the reference exhaust valve timing.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442643","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 investigations of a desiccant-coated M-cycle cooler as a step towards net zero air-conditioning","authors":"","doi":"10.1016/j.enconman.2024.119146","DOIUrl":"10.1016/j.enconman.2024.119146","url":null,"abstract":"<div><div>Despite having the potential to be adopted as a solution towards net-zero emission-based air-conditioning systems, desiccant-evaporative cooling systems have limited applications due to the need to combine several systems to achieve the target conditions. This paper, therefore, undertakes an experimental analysis of a compact system that integrates solid desiccant dehumidification and M−cycle cooling in a single heat exchanger. The system then undergoes regeneration and cooling stages, where no air-conditioning occurs. It is observed that the system can achieve thermal comfort for almost all inlet conditions. Parametric analysis also shows that varying the inlet humidity ratio impacts the system output more than the inlet DBT. The overall cooling capacity of the system increases with greater channel velocity and peaks at around 30 % branching ratio. The concept of operational time (dehumidification stage) and downtime (regeneration and cooling stages) has also been investigated. The analysis shows that the operational time is more than the downtime for all cases except when channel velocity increases above 2.4 m/s. It is also observed that the operational time becomes double the downtime when the regeneration temperature exceeds 83 ℃. Therefore, the analyses practically demonstrate the combined reduction of sensible and latent loads through a simultaneous adsorption-evaporation phenomenon as a step towards a net zero emission-based air-conditioning system.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432782","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 on heat transfer characteristics and Capillary-Assisted enhancement of Dual-Phase immersion battery thermal management system","authors":"","doi":"10.1016/j.enconman.2024.119149","DOIUrl":"10.1016/j.enconman.2024.119149","url":null,"abstract":"<div><div>With increasing demands for thermal management in power batteries, the dual-phase immersion thermal management system, despite its exceptional cooling performance, continues to be hampered by its substantial weight and cost. This study employs experimental methodologies to investigate the heat and mass transfer mechanisms of dual-phase immersion cooling, focusing on ambient temperature, thermodynamic analysis, and visualization. The results demonstrated that dual-phase immersion cooling could maintain the maximum temperature difference within 2.8°C at 4C discharge rate. Based on this, a novel dual-phase semi-immersed cooling scheme is proposed, which utilizing hydrophilic foam copper to achieve the coexistence of pool boiling and film evaporation heat transfer modes. Owing to the incorporation of the foam copper suction effect, the maximum temperature of the battery pack decreases by approximately 5.2 °C at the same 25 % immersion depth. Compared to conventional dual-phase immersion cooling systems, this scheme achieves comparable cooling efficiency while reducing coolant usage by approximately 76.8 %. Furthermore, a control strategy developed based on condenser circulation effectively limits the temperature of the experimental battery module during 4C discharge to below 38 °C, with a power consumption of only 5.1 Wh.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442544","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 novel theory for designing SI engines based on exergy efficiency, entropy, octane rating, and fuels’ physicochemical properties for Otto cycles","authors":"","doi":"10.1016/j.enconman.2024.119144","DOIUrl":"10.1016/j.enconman.2024.119144","url":null,"abstract":"<div><div>It is presented a novel theory for designing spark ignition (SI) engines based on tests in three SI engines, three scientific methodologies, and thermodynamics laws applied to Otto cycles. Mathematical modeling used the optimal thermal efficiency for the Otto cycle and data on octane rating for liquid fuels and the methodology for methane number for gaseous fuels. Before, two methodologies had been developed for quantitative estimation of energy quality and exergy efficiency for gaseous fuels in SI engines. Equations are proposed to correlate exergy efficiency, entropy, energy recovered, maximum thermal efficiency, and certain fuel physicochemical properties for SI engines. Also, tests and correlations between fuel properties and octane rating are presented to validate the hypothesis. Besides, it presented the performance data of an SI engine converted and optimized for biogas, which was designed and scaled based on this theory. The engine has a high compression ratio with pistons selected for high turbulence, getting greater output power and efficiency with biogas compared with diesel and natural gas. Due to biogas’s physicochemical properties (the highest-octane rating, low energy density, low laminar flame speed, and low adiabatic flame temperature), its combustion resulted at high pressure and high turbulence intensity with better performance than diesel oil. According to exergy efficiency for internal combustion engines is better to use biogas, biomethane, and natural gas instead of fuels like diesel and gasoline.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442539","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":"Techno-economic analysis of hydrogen production from offshore wind: The case of Brazil","authors":"","doi":"10.1016/j.enconman.2024.119109","DOIUrl":"10.1016/j.enconman.2024.119109","url":null,"abstract":"<div><div>Given the need to reduce carbon emissions, research related to hydrogen production using renewable energy sources has increased in the last few years by academia and industry. Hydrogen production using offshore wind energy has shown high potential, however, there are many technological and economic challenges to production using offshore wind power. This research presents a techno-economic model to estimate and analyze the hydrogen production potential and levelized cost of hydrogen using offshore wind energy, considering technical and environmental constraints. The analysis considers two off-grid scenarios, including offshore and onshore hydrogen production using offshore wind energy. The wind turbines’ power and electrolyzers’ efficiency curves are used to estimate energy generation and hydrogen production, respectively. The cost model is developed based on the region characteristics and process configuration. The developed process is applied to the Brazilian coastline as a case study. The results reveal excellent hydrogen potential in regions with water depths of up to 200 m and distances of up to 200 km from the ports. A minimum value of 4.76 $/kg is found in the Northeast region for the offshore scenario. Moreover, hydrogen production in the offshore scenario is more cost-effective than the onshore scenario. Considering the visual impact constraints of 40 km of distance from the coastline, the results present a reduction of around 25% of the hydrogen potential, showing the importance of research and development for floating platforms to support the wind turbines. Additionally, the research indicates that the optimal sizing of the wind farm-electrolysis system can reduce the cost of hydrogen production. The results from the research work can contribute to design strategies and support decision-making for offshore wind-powered hydrogen projects.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":null,"pages":null},"PeriodicalIF":9.9,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432778","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}