Hasil untuk "Fuel"

Xinlu Han, Zhihua Wang, Mário Costa et al.

Abstract Ammonia (NH3) is a promising energy carrier to store and transport renewable hydrogen (H2) that can be generated using, e.g., wind and solar energy. Direct combustion of NH3 is one of the possible methods to utilize the energy by the end users. To understand the combustion characteristics of NH3 as a fuel, the laminar burning velocities of NH3/air, NH3/H2/air, NH3/CO/air and NH3/CH4/air premixed flames were investigated experimentally using the heat flux method. Measurements are reported for a wide range of equivalence ratios and blending ratios. Kinetic modeling was also performed using available chemical kinetic mechanisms, namely the GRI-Mech 3.0, the Okafor et al. and the San Diego mechanisms. The experimental results for NH3/air flames agree well with the literature data and it is found that blending NH3 with H2 is the most effective manner to increase the burning velocity of NH3 based fuel mixtures. None of the kinetic mechanisms used can accurately predict most of the measured data. Sensitivity and reaction path analyses indicate that the oxidation of NH3 blended with the additive fuels considered can be understood as the parallel oxidation processes of the individual fuels, and that the source of discrepancy between the experimental and modeling results is related to the inaccuracy of the rate parameters of the N-containing reactions. In this regard, the present detailed and reliable experimental data is of special value for model development and validation.

D. M. Alonso, Stephanie G. Wettstein, J. Dumesic

Chao Jin, M. Yao, Haifeng Liu et al.

G. Knothe

Y. Sharma, Bhaskar Singh, S. N. Upadhyay

Jing Liu, Menggai Jiao, Lanlu Lu et al.

For the large-scale sustainable implementation of polymer electrolyte membrane fuel cells in vehicles, high-performance electrocatalysts with low platinum consumption are desirable for use as cathode material during the oxygen reduction reaction in fuel cells. Here we report a carbon black-supported cost-effective, efficient and durable platinum single-atom electrocatalyst with carbon monoxide/methanol tolerance for the cathodic oxygen reduction reaction. The acidic single-cell with such a catalyst as cathode delivers high performance, with power density up to 680 mW cm−2 at 80 °C with a low platinum loading of 0.09 mgPt cm−2, corresponding to a platinum utilization of 0.13 gPt kW−1 in the fuel cell. Good fuel cell durability is also observed. Theoretical calculations reveal that the main effective sites on such platinum single-atom electrocatalysts are single-pyridinic-nitrogen-atom-anchored single-platinum-atom centres, which are tolerant to carbon monoxide/methanol, but highly active for the oxygen reduction reaction. High-performance electrocatalysts for the oxygen reduction reaction (ORR) typically use platinum (Pt), however its high cost is a hindrance to commercial scale up. Here, the authors report a cost-effective, efficient and durable Pt single-atom electrocatalyst for ORR with a Pt utilization of 0.13 gPt kW−1in a fuel cell.

A. Demirbaş

Christopher White, R. Steeper, A. Lutz

C. Musardo, G. Rizzoni, Y. Guezennec et al.

G. Peters, G. Marland, Corinne Le Quéré et al.

K S Gallagher, E. Muehlegger

Takács Richárd, Vacula Jirí, Prinsier Johan

Low-pressure exhaust gas recirculation (LP-EGR) is promising strategy for reducing NOx emissions in internal combustion engines, but it presents challenges due to water vapor condensation that can lead to compressor impeller erosion. This study presents a comprehensive thermodynamic analysis to quantify condensate formation and determine dew point temperatures across varying fuels and engine operating conditions. Novel mathematical models are developed to estimate specific humidity and condensation using only standard engine parameters, making them applicable without additional sensors. Results show that both fuel composition - particularly the hydrogen-to-carbon ratio - and LP-EGR rates strongly influence condensation. The study also highlights the impact of alternative fuels and ambient conditions on condensation risk. The developed methodology supports real-time evaluation of condensation potential and offers critical input for erosion risk assessment, component design, and emission control strategy optimization in modern powertrain.

Anubhav Kumar Pandey, Chaima Mansour, Nandini K. K. et al.

Abstract This paper reports the optimum operation of a virtual power plant (VPP) to reduce the reliance on coal and gas-based energy generation. This practice not only promotes the incorporation of renewable-based energy sources but also reduces the reliance on fossil-based resources which are limited in the reserves. The selected VPP system comprises small hydropower, wind turbine, solar photovoltaics and fuel cells accompanied by a co-generation unit. The proposed VPP is also equipped with a storage facility applicable as a flexible storage option i.e., an electric vehicle followed by an energy storage system. In addition, the primary objective of this work is to lessen the overall cost associated with the system along with a reduction in the generated emissions. Moreover, a Golden Jackal-based Optimization inspired by nature is utilized in a single and multi-objective framework to attain the desired target objectives. Furthermore, the scheduling of the VPP system is carried out on a day-ahead basis and the outcome in terms of cost and emission is compared with the available work in the literature and the result reveals the effectiveness of the system in terms of quality solutions sets for the objectives, minimum computational time and better convergence behavior. In particular, there is a reduction in cost by 2.1% and 0.62% when compared with the salp swarm algorithm and beluga whale algorithm followed by 2.12% and 1.18% in emission. Furthermore, the cost/emission of the VPP system is also abridged by employing a Pareto-based approach which shows the suitability and effectiveness of the developed system.

Dellah Tian Saputri, Amin Rejo, Rizky Tirta Adhiguna

Abstract: Pelabuhan Dalam Village, Ogan Ilir, is a swamp–lowland agricultural area dominated by rice cultivation. Challenges such as the decline in productive labor, the use of conventional tractors that cause soil compaction, and the low participation of women and the elderly have led to socio-economic and ecological problems. This study integrates a socio-agroecosystem approach through the implementation of semi-autonomous hand tractors to improve technical efficiency and community empowerment. The results show a 31% increase in work efficiency, a 17% reduction in fuel consumption, and a 21% decrease in soil compaction. The participation of women and the elderly also increased, accompanied by a 16% rise in household income per planting season. This integration has proven effective in promoting socio-economic welfare and the sustainability of wetland agriculture in South Sumatra.

Chamara Panakaduwa, Paul Coates, Mustapha Munir

Retrofitting the existing housing stock to a high level of energy efficiency will not be limited to achieving the decarbonisation of 80.3 MtCO2e residential emissions and reducing fuel poverty in 4.16 million households, but also improving the health and well-being of UK residents and their overall quality of life. The current progress of housing retrofitting is poor, at less than 1%. The UK expects to achieve net zero by 2050, and the challenge is immense as there are more than 30 million houses. The challenge is similar in other global contexts. Even if the required technology, supply chain, skilled labour, and finance could have been provided, the retrofitting would not move forward without positive engagement from the clients. Proper strategies are required to retrofit at scale. Focusing on the challenges of stakeholder engagement in housing retrofitting, this study focused on developing a hybrid one-stop shop solution through design science research. A theoretical artefact and an empirical system requirement specification document were developed to propose a one-stop shop solution. This was tested through retrofit industry stakeholders. Findings reveal that the one-stop shop model will be a good answer to retrofitting at scale, providing the resident engagement of 30.1 million households. The model can support residents with or without computer literacy due to its hybrid approach. The proposed theoretical and industrial models can be used as base models for developing one-stop shops for housing retrofitting by adapting them for context-specific requirements.

Nguyen Huu Hieu, Bui Van Hung, Ho Tran Ngoc Anh et al.

Direct injection through a twining injector system enables an increase in output power of dual-fuel engines, improves speed control capacity, and allows the engine to use flexible gaseous fuel blends of syngas-biogas-hydrogen with large variation of compositions. When the injection pressure is reduced from 5 bar to 3 bar, the start injection angle is advanced by 20°CA and the gauge pressure in the cylinder drops by 0.1 bar. In syngas fueling mode, with an injection pressure of 3.5 bar, to achieve f=0.75 at a crankshaft position of 250°CA, the start injection angles are 80°CA, 50°CA, and 25°CA corresponding to engine speeds of 2000 rpm, 2400 rpm, and 2800 rpm, respectively. The gauge pressure in the cylinder increases by 100%, 97%, and 79%, respectively, compared to natural aspiration fueling mode.

Huan Liu, Hong-Wu Song, Si-Ying Deng et al.

A positioning grid is a key clamping structure for fixing the transverse and axial positions of fuel assemblies in nuclear reactors, and it is generally prepared by the transverse stamping of a Zr-4 sheet. However, the texture formed in the processing process of Zr-4 sheets can affect formability, resulting in cracking in the stamping process. Therefore, the relationship between the formability of Zr-4 sheets and the normal Kearns factor (Fn) of basal texture was studied in this paper. The results showed that the Zr-4 sheet with an Fn equaling 0.720, prepared by an isobaric reduction rolling process, would crack in the stamping process. To avoid the cracking during stamping, the formability improvement of Zr-4 sheets based on texture optimization was discussed. By using the finite element model (FEM) and a visco plastic self-consistent (VPSC) model coupled simulation, the relationship between the initial textures and formabilities of Zr-4 sheet is established. It is found that the hardening exponents (n) decreased with increasing Fns in VPSC simulations. Meanwhile, as the Fn increases, cracks are prone to occur at the bottom corner of the stamped sheet in finite element simulation. Given the results from FEM and VPSC simulations, it is proposed that the Fn should be controlled to be less than 0.7 for preventing cracks in the sheet during stamping. Additionally, a new rolling process named non-isobaric reduction rolling was designed in which the Fn of the Zr-4 sheet is successfully reduced to 0.690. The stamping results indicate that the sheet is free of cracks under an Fn of 0.690. Therefore, texture optimization with the proposed rolling process can improve the formability of Zr-4 sheets, which effectively solves the cracking problem of Zr-4 sheets.

LIN Qin, WANG Yujiao, CHENG Ming et al.

BackgroundAn electrolyte waste salt containing LiCl and various products is generated during the pyroprocessing of spent nuclear fuel in metal fast reactors. Separating metal impurities from waste salt can purify molten salt, facilitate salt recycling, and reduce the amount of waste salt, achieving waste minimization.PurposeThis study aims to investigate the effects of key factors on the application of the cold finger crystallization method used for removal of Sr and Ba from molten LiCl salt.MethodsA homemade cold finger experimental apparatus was applied to the experimental removal of two alkaline earth metals, Sr and Ba, from molten LiCl salt, and Fluent software was employed to simulate the application of cold finger crystallization equipment during dry reprocessing. The effects of crystal growth time, initial crystallization temperature, and initial SrCl2/BaCl2 concentrations on the removal ratio of the crystalline salt during the process were analyzed.ResultsThe initial temperature of molten salt is a critical factor that influences cold finger separation efficiency. When the initial temperature reaches 660 ℃, the removal efficiency improves. Moreover, when the impurity contents of Sr and Ba in molten salt are lower than 0.55%(w/w), the removal efficiency of the cold finger crystallization method can exceed 80%. Further analysis shows that the removal effects of different parts of molten salt crystals differ. The solvent salt at the top of the molten salt crystal is better, and the removal ratio of the bottom and inner salts is lower. Therefore, the optimal conditions for removing Sr and Ba from LiCl crystalline salt require an initial temperatures of 660~670 ℃, an airflow intensity of 10 L·min-1, and a growth time of 20 min. Under these optimal conditions, the removal ratio can reach 90%.ConclusionsThe proposed approach is feasible for purifying solvent salts from electrolyte waste molten salt via cold finger crystallization. This study provides a reference for purifying waste salt and reusing molten salt.

Jaewon Yoo, Myung Seok Lee, Yang Jae Kim et al.

In this study, we fabricated thin film solid oxide fuel cells on nanoporous anodic aluminum oxide (AAO) substrate for low-temperature operation using the all-through sputtering method. To deposit up to a three-micrometer thick anode with both porosity and electrical conductivity, we used the glancing angle deposition and co-sputtering methods. For the anode materials, we used nickel gadolinium-doped-ceria (Ni-GDC) mixed ionic and electronic conductor (MIEC), which improved hydrogen oxidation reaction reactivity at the anode side. TF-SOFCs were successfully operated at 500oC, and 223.6 mW/cm2 was their highest measured maximum power density. We conducted structural and electrochemical analyses to figure out cells’ unique resistant characteristics; ohmic resistance through the anode thin film and polarization resistance of reaction area near the narrowed anode pores. We found how the anode thin film thickness affects the current collecting performance and the anode reactivity, and their effects were qualitatively and quantitatively compared.

Kai Xiao, Daoxing Li, Xiaohui Wang et al.

Integrating marketing and distribution businesses is crucial for improving the coordination of equipment and the efficient management of multi-energy systems. New energy sources are continuously being connected to distribution grids; this, however, increases the complexity of the information structure of marketing and distribution businesses. The existing unified data model and the coordinated application of marketing and distribution suffer from various drawbacks. As a solution, this paper presents a data model of “one graph of marketing and distribution” and a framework for graph computing, by analyzing the current trends of business and data in the marketing and distribution fields and using graph data theory. Specifically, this work aims to determine the correlation between distribution transformers and marketing users, which is crucial for elucidating the connection between marketing and distribution. In this manner, a novel identification algorithm is proposed based on the collected data for marketing and distribution. Lastly, a forecasting application is developed based on the proposed algorithm to realize the coordinated prediction and consumption of distributed photovoltaic power generation and distribution loads. Furthermore, an operation and maintenance (O&M) knowledge graph reasoning application is developed to improve the intelligent O&M ability of marketing and distribution equipment.