JOM最新文献

Hydrogen-powered heavy-duty vehicles will transform the logistics landscape, but their extensive adoption presents substantial challenges. Matching hydrogen demand with supply, scaling up infrastructure, controlling carbon emissions targets, and integrating with renewable energy sources are significant obstacles to overcome. This paper addresses these challenges by modeling a hydrogen station for heavy-duty vehicle fleets using Matlab-Simulink software. The hydrogen station components proposed are individually modeled: (1) the electrolyzer model generates hydrogen and oxygen by electrolysis consuming water and electricity; (2) the hydrogen reformer model generates hydrogen and carbon dioxide through steam methane reforming or ethanol reforming; (3) the hydrogen storage tank; and (4) carbon capture and storage. These models were compiled into functional mock-up units (FMU) to facilitate further exploration. This paper incorporates metaheuristic optimization techniques to address the design complexities and enhance the performance of hydrogen stations under various operating conditions. Multiple optimization objectives have been considered, including reducing carbon emissions and reducing the total monetary cost. Furthermore, several critical constraints are integrated to ensure realistic scenarios. These constraints include the accumulated hydrogen production that meets daily demand and the limitations in resource consumption. Finally, the combination of the FMU approach with metaheuristics techniques demonstrates the potential for the optimal hydrogen infrastructure design.

Moving from fossil fuel power generation to renewable energy generation brings a number of challenges that must be addressed. Generating energy intermittently is one of the main problems of renewable energy sources, requiring energy storage systems to be able to respond to demand when energy is not being generated. There are many types of energy storage systems. Among them, one of the most interesting in the last decades has been vanadium redox flow batteries (VRFBs) because of their long lifetime and scalability. The performance of VRFBs is affected by many different parameters, including the electrolyte flow rate. This paper presents a performance study of a VRFB battery operating with different charge and discharge currents and different electrolyte flow rates. The experiments were carried out using numerical models that model the mass transfer dynamics, the hydraulic system to calculate pressure losses and the shunt currents of a VRFB.

This study examined the effects of laser processing conditions on the evolution of microstructure and phase fractions in HT9 ferritic/martensitic (F/M) steels fabricated using laser powder bed fusion (L-PBF) and laser-directed energy deposition (L-DED). Electron backscattered diffraction (EBSD) micrographs of the cross-sections of the laser-processed builds showed the presence of α-ferrite, α′-martensite, and retained austenite (γ). Distinct differences were observed in the γ phase fraction between the L-PBF and L-DED microstructures. To correlate the observed phase fractions with process-induced thermokinetic effects, a multiscale multiphysics thermal model was used. The modeling results confirmed the experimental data and provided insight into the relationship between temperature changes during processing and phase evolution in HT9 steel.