Experimental Simulation Study Research Articles

Enhanced electrochemical performance of direct carbon solid oxide fuel cells by MgO-catalyzed carbon gasification: Experimental and DFT simulation studies

Direct carbon solid oxide fuel cells (DC-SOFCs) are high-efficiency and clean power generation systems that can directly utilize solid carbon to produce electricity. However, the cell performance is hampered by the sluggish kinetics of the reverse Boudouard reaction at operating temperatures, as dictated by their operational principle. Here, carbon fuels loaded with varying amounts of MgO catalyst were successfully developed to promote the reverse Boudouard reaction and DC-SOFC performance. At 850 °C, the DC-SOFC powered by 5 wt% Mg-loaded activated carbon achieved peak power output of 236 mW cm−2, demonstrating a notable enhancement of 41.3% compared to that of 165 mW cm−2 in pure activated carbon-fueled cell. Furthermore, the single cell discharged stably for a prolonged duration of 41.6 h under 50 mA, achieving a noteworthy fuel utilization of 33.3% at 850 °C. These underscored the substantial contribution of MgO to the enhancement of DC-SOFC performance and efficiency. More importantly, the MgO catalyst displayed excellent stability without agglomeration during the high-temperature operation of the cell. Density functional theory simulation confirmed experimental findings that MgO reduced the energy barrier of carbon gasification reaction, thereby providing sufficient carbon oxide for cell operation. Finally, the reaction paths and internal mechanism of MgO-catalyzed carbon gasification were proposed to offer theoretical backing for the effective conversion of solid carbon fuel and improvement of cell performance. This study offers original perspectives on advancing carbon gasification reaction catalysts to facilitate the stable and highly efficient operation of DC-SOFCs, contributing to reduced carbon emissions and advancing sustainability.

Flow Behavior through Porous Media and Displacement Performance of a SILICA/PAM Nanohybrid: Experimental and Numerical Simulation Study.

Nanoparticles (NPs) have been proposed as additives to improve the rheological properties of polymer solutions and reduce mechanical degradation. This study presents the results of the retention experiment and the numerical simulation of the displacement efficiency of a SiO2/hydrolyzed polyacrylamide (HPAM) nanohybrid (CSNH-AC). The CSNH-AC was obtained from SiO2 NPs (synthesized by the Stöber method) chemically modified with HPAM chains. Attenuated total reflection-Fourier transform infrared spectroscopy, field emission gun-scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis were used to characterize the nanohybrid. The injectivity and dynamic retention tests were performed at 56 °C in a sandstone core with a porosity of ∼26% and a permeability of 117 and 287 mD. A history matching of the dynamic retention test was performed to determine the maximum and residual adsorption, IPV, and residual resistance factor (RRF). A laboratory-scale model was used to evaluate the displacement efficiency of CSNH-AC and HPAM through numerical simulation. According to the results, the nanohybrid exhibits better rheological behavior than the HPAM solution at a lower concentration. The nanopolymer sol adsorption and IPV (29,7 μg/grock, 14,5) are greater than those of the HPAM solution (9,2 μg/grock, 10), which was attributed to the difference between the rock permeabilities used in the laboratory tests (HPAM: 287 mD and CSNH-AC: 117 mD). The RF of both samples gradually increases with the increase in shear rate, while the RRF slightly decreases and tends to balance. However, the nanopolymer sol exhibits greater RF and RRF values than that of the polymer solution due to the strong flow resistance of the nanohybrid (higher retention in the porous media). According to the field-scale simulation, the incremental oil production could be 295,505 and 174,465 barrels for the nanopolymer sol and the HPAM solution, respectively (compared to waterflooding). This will represent an incremental recovery factor of 11.3% for the nanopolymer sol and 6.7% for the HPAM solution.

Clay minerals/sodium alginate/polyethylene hydrogel adsorbents control the selective adsorption and reduction of uranium: Experimental optimization and Monte Carlo simulation study

Clay minerals formations are potential geological barrier (host rocks) for the long-rerm storage of uranium tailing in deep geological repositories. However, there are still obstacles to the efficient retardation of uranium because of the competition between negatively charged regions at the clay minerals end face, surface and between layers, as well as low mineralization capacity. Herein, employing a simple method, we used sodium alginate (SA), an inexpensive natural polymer material, polyethylene (PE), and the natural clay minerals montmorillonite (Mt), nontronite (Nt), and beidellite (Bd) to prepare three hydrogel adsorbents, (denoted as Mt/PE-@SA, Nt/PE-@SA, and Bd/PE-@SA), respectively. The application of obtained hydrogel adsorbents further extends to uranium(VI) removal from aqueous. Due to the synergistic action of SA group and PE group, hydrogel adsorbents showed select adsorption and mineralization effect on uranium(VI), among which the maximum uranium(VI) adsorption capacity of Nt/PE-@SA was 133.3 mg·g-1 and Mt/PE-@SA exhibited strong selectivity for uranium(VI) in the presence of coexisting metal ions. Cyclic voltammetry studies indicated the mitigation and immobilization of uranium species onto adsorbents by both reduction and mineralization. Besides, the synergistic adsorption of SA and PE on clay minerals was hypothesized, and the idea was supported by structure optimizations results from Monte Carlo dynamics simulation (MCD). Three obtained hydrogel adsorbents structural model was constructed based on its physicochemical characterization, the low energy adsorption sites and adsorption energies are investigated using MCD simulation. The simulation results show that obtained hydrogel adsorbents have a strong interaction with uranium(VI), which ensures the high adsorption capacity of those materials. Most importantly, this work demonstrates a new strategy for preparing mineral-based hydrogel adsorbents with enough stability and provides a new perspective for uranium(VI) removal in complex environment.

Mode transformation of dynamic spin wave well modes in the magnetic stripes

In this work, we present an experimental and micromagnetic simulation study of the mode transformation of dynamic spin wave well modes in the magnetic stripes. With a highly precise lock-in ferromagnetic resonance measurement system, the spin wave modes, including the quantized backward volume magnetostatic spin waves and the spin wave well modes, can both be clearly detected in the transversely magnetized stripes. The mode transformations of dynamic spin wave well modes are detected in a field range that the moments near the edge of the stripe are not fully magnetized. Further micromagnetic simulation and analyzation show that the boundary condition change in the potential well might be the main reason for the mode transformation of spin wave well modes. These results might be helpful for the further understanding of the spin wave dynamics in the finite ferromagnets.

An experimental and molecular simulation study on the soot formation characteristics and mechanism in hydrogen-ammonia blended ethylene combustion

Extinction measurement and thermophoretic sampling techniques were employed to investigate the soot formation characteristics in H2-NH3 blended C2H4 combustion. And the formation mechanism of benzene (A1) was analyzed using reactive molecular dynamics simulation (ReaxFF MD), unveiling the chemical coupling effects on soot formation at the molecular level. As the hydrogen/ammonia (H2/NH3) ratio decreases, the flame height decreases gradually, the flame brightness noticeably darkens, and the dark non-sooting core continuously increases. The maximum of soot volume fraction (fvmax) gradually decreases and shifts from the flame wing towards the flame centerline. Addition of H2-NH3 leads to an increase in the proportion of small-sized fringes and fringe tortuosity, resulting in an increase in the oxidation activity and a decrease in the fv. The largest soot particle contains a small amount of nitrogen atom (N). Some of these N atoms replace hydrogen atom (H) to bond with carbon ring, while others substitute for carbon atom (C) to form nitrogen ring, ultimately resulting in nitrogen-containing polycyclic aromatic hydrocarbons (PAHs) and nitrogen-containing soot. The reduction in the H2/NH3 ratio leads to a reduction in C in the largest soot particle, which more effectively inhibits soot formation and graphitization. On the other hand, it increases the N and nitrogen ring in the largest soot particle. It is possible that the increase in NH3 proportion favors N in competition with H for active sites on soot particles. A1-+H↔A1 is the most crucial reaction pathway of A1 formation. As the H2/NH3 ratio increases, H2 concentration significantly rises, leading to an enhancement in the forward reaction rate. Furthermore, the competition for H between H2 and NH3 by NH3+H↔NH2+H2 results in a chemical coupling effect on soot formation.

Evaluation of Wetting Behaviors of Liquid Sodium on Transition Metals: An Experimental and Molecular Dynamics Simulation Study.

In sodium-cooled fast reactors, the wettability of sodium with materials is closely related to sodium-related operations and the detection accuracy of instruments and meters, so how to achieve the selection of materials with different wettability requirements is a key problem in engineering design. To meet these requirements, the wetting behaviors of liquid sodium with nine transition metals were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and molecular dynamics (MD) simulations. The results show that metals such as zinc and gold, which react with sodium to form intermetallic compounds at the interface, exhibit superior wettability. Followed by the metals that have strong interatomic interactions even though they do not react with sodium or dissolve each other, such as cobalt, nickel and copper, while the wettability of these systems tends to be poor at low temperatures. Systems that do not react with each other or have strong interatomic affinities proved to be the most difficult to wet. Notably, metals with the closest-packed crystal structures of fcc and hcp generally have better wettability than those with a bcc structure. They can be a valuable guide for experimental research and technical control.

Experimental and numerical simulation study on the dispersion and explosion process of solid-liquid-air mixed three phase components

The diffusion of solid-liquid fuel and the explosion of three-phase mixed cloud were studied experimentally in an unconstrained external field. The formation and explosion process of solid-liquid fuel clouds was implemented using numerical simulation methods, and param such as cloud diameter, cavity diameter, cloud concentration, fireball temperature, and overpressure distribution were obtained. The results show that the cloud cluster expands rapidly in the early stage of fuel dispersal, and gradually enters the turbulent diffusion stage after 20 ms. At 40 ms, the diameter of the cloud cluster is about 4.97 m, the volume of the cloud cluster is 18.31 m3, and the fuel concentration is mainly in the range of 30 g m−3–80 g m−3. The error between the scattering and explosion processes of numerical simulation and experimental results is less than 10 %, proving the reliability of the simulation model. This study can guide the prevention of industrial disasters.

Large-Scale Experimental Simulation Studies on Rainfall-Induced Landslides Using Artificial Rainfall Simulator and Its Evaluation Using Conventional- and Optical-Based Monitoring Method

Large-Scale Experimental Simulation Studies on Rainfall-Induced Landslides Using Artificial Rainfall Simulator and Its Evaluation Using Conventional- and Optical-Based Monitoring Method

Experimental and Numerical Simulation Study of Water Infiltration Impact on Soil-Pile Interaction in Expansive Soil

A laboratory model of a single pile embedded in Nanyang expansive soil and subjected to water infiltration is applied in this study to examine the interaction between the expansive soil and pile foundation upon water infiltration. The soil matric suction decreases as a result of the rising soil-water content. The amount of soil ground heave reaches its peak of 10.7 mm after 200 hours of water infiltration. As matric suction decreases, pile shaft friction also declines, which causes more of the load at the pile head to be carried by the pile base resulting in more pile settlements. A new numerical simulation method is provided to simulate this issue by coupling the subsurface flow, soil deformation, and hygroscopic swelling to investigate the expansive soil-pile response upon water infiltration. From the numerical simulation model, hygroscopic strain arises as a result of elevated moisture levels resulting from the entry of water, and due to ground heave and the mobilization of lateral soil swelling, the shear stress at the interface between the soil and the pile gradually increases over time. It reaches its maximum value of 4420 Pa at upper depths around 200 hours after the infiltration. The comparison between the lab model testing data and the numerical model results demonstrates a good level of concurrence.

Calculation method for flexural capacity of composite girders with corrugated steel webs

Experimental and numerical simulation studies were conducted to investigate the differences in bending performance between steel I-girder composite girders with corrugated steel webs (CSWs) and traditional steel I-girder composite girders with flat steel webs (FSWs). The flexural capacity calculation method specified in Eurocode 4 is applied to steel I-girder composite girders with FSWs. However, using the method of steel I-girder composite girders with CSWs revealed an error of approximately 25% between the calculated results and the experimental results. This paper employed the continuous strength method to conduct an elastic–plastic analysis of steel I-girder composite girders with CSWs, considering both the bending contribution of CSWs and the strengthening effect of the steel girder. A calculation method for the flexural capacity suitable for composite girders with CSWs was also introduced. Remarkably, the research outcomes indicated that under ultimate loads, the webs of the steel I-girder composite girder with FSWs underwent buckling deformation. In contrast, the webs of the steel I-girder composite girder with CSWs remained intact, showcasing excellent buckling stability. Compared to the calculation results of the formula specified in Eurocode 4, the accuracy of the proposed calculation method in this paper is improved by 17%. This method can effectively predict the flexural capacity of composite girders with CSWs and is suitable for practical engineering applications.

Factors affecting the daytime cooling effect of cool materials: A case study combining experiment and simulation

Cool materials, with their high reflectivity, can significantly reduce the heat absorbed by buildings in summer and thus reduce energy consumption. The amount of solar radiation received by building surfaces varies with their orientation, so the effectiveness of cool materials on different building surfaces may vary. This study investigated the effects of using cool materials on scaled-down building models and full-scale real buildings through a combination of experiments and simulations, considering factors including building surfaces of different orientations, material properties, and weather conditions. Both experimental measurements and simulation studies showed that applying cool materials on roofs has the best cooling effect, reducing indoor temperatures by 0.93 °C in full-scale models. The south and west façades also showed good cooling effects when using cool materials. The north façade has the least cooling effect when using cool materials. Compared to exposed cement boards and regular materials, cool materials showed significantly better cooling effects, similar to those of 2 cm thick XPS insulation boards. Overall, buildings with poorer thermal insulation performance benefit more from the cooling effect of cool materials in summer. Additionally, the cooling effect of cool materials is ineffective on cloudy and rainy days. We found that the cooling effect of cool materials was significantly reduced when the solar radiation was less than 400 W/m2. The findings of this study provide guidance for the use of cool materials in energy retrofitting of existing buildings and the construction of low-carbon cities.

Experimental and numerical simulation study on coupling tripping of partial trapezoidal threaded casing head and casing coupling

Casing connection is a common connection method in oil and gas reservoir production, and the tripping of casing will seriously hinder the production process. To study the casing tripping process and the minimum tensile load required for casing tripping under different loosening buckle states, three kinds of casing tripping tensile tests were carried out. The thread morphology of the casing head and casing coupling was analyzed by local cutting at the end of the experiment, and the thread failure area was analyzed by scanning electron microscope, and then other loosening states were studied and analyzed using numerical simulation. The research results show that as the number of loosening buckles increases, the minimum tensile load required for the casing head and casing coupling to trip decreases. The observation of the thread shape shows that the thread part of the casing head was seriously damaged. Scanning electron microscopy results show that the fracture mode at the thread of the casing head is ductile fracture. Numerical simulation results show that the maximum stress area during the tripping process is at the contact position between the thread heads. Based on the experimental and numerical simulation results, the relationship between the number of casing loosening and the minimum tensile load required for casing tripping is obtained. The research results can be used as the experimental and theoretical basis for the investigation of casing tripping accidents and can also provide experimental reference for the design of the next-generation of casing.

Performance of a new pyrazole derivative in 1 M HCl on the corrosion of carbon steel: experimental, quantum chemical and molecular dynamics simulation studies

The present research demonstrates an innovative investigation of a new pyrazol derivative (2-benzoyl-4-nitro-N-[(1H-pyrazol-1-yl)methyl]aniline (BNPMA)) as an inhibitor of carbon steel corrosion in molar hydrochloric acid. A variety of methods and techniques were used in our research to assess corrosion inhibition, including weight loss measurements (WL), electrochemical trials like potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), surface analysis methods such a scanning electron microscope coupled with Energy-Dispersive X-ray Spectroscopy (SEM/EDX), UV-Visible analysis, as well as computational evaluation of BNPMA. The organic compound was confirmed to be a good anticorrosive product with a maximal inhibition efficiency (IE%) of 93.2% at 10−3 M. According to the PDP results, the inhibitor BNPMA acts as a mixed-type inhibitor. The Langmuir model seems to be followed during BNPMA's adsorption on the CS surface. According to UV-visible and scanning electron microscopy, a barrier coating was formed which prevented corrosive ions from reaching the CS surface. The outcomes of experimental approaches (WL, PDP, and EIS) have been supported by theoretical investigations.

Experimental and LBM simulation study on the effect of bubble merging on saturated pool boiling in pure water

Experimental and LBM simulation study on the effect of bubble merging on saturated pool boiling in pure water

Simulation modelling of hydrogen production from steam reforming of methane and biogas

The use of fossil fuels in energy systems has environmental consequences, which are driving investigations into H2 production. While steam methane reforming is the most well-known method for producing H2, other thermochemical pathways are becoming more prevalent. Steam-reforming of biogas is also a beneficial procedure for producing eco-friendly hydrogen gas and minimizing the burden on fossil fuels. In this study, a simulation modelling of steam methane reforming (SMR) and steam biogas reforming (SBR) are presented. The model reveals the hydrogen production reaction mechanism and validates its performance through simulation analysis using COMSOL Multiphysics 5.6 software (finite element analysis). The developed model has been validated by available previous experiments and simulation work for biogas reforming with various compositions as well as the methane reforming process. The core aim of this study is to estimate the yield of H2 for SMR, and H2 and CO for SBR at steam carbon ratio (S/C) from 1 to 3 with various temperatures, and find the optimum temperature for the reforming process. The yields of hydrogen (mol/mol-CH4) are achieved higher from SMR as 12% and 22 % for comparison with the experiment and previous simulation study at S/C = 2, at a temperature of 700 °C. The H2 yields (mol/mol-CH4) are achieved higher as 30% at 800 °C, 21% at 1000 °C, and 20% at 1200 °C (average percentage of mol for steam carbon ratio from 1 to 3) and compared with previous simulation study at the same operating temperatures, stated by SBR. The findings indicate that the proposed work offers a viable method for utilizing distributed renewable methane resources to fuel cells and generate local electricity.

Potential of green-based microporous carbon for advanced water decontamination from azo dyes: Experiment and molecular dynamic simulation studies

Due to severe limitations in clean water resources, there has been an intensified focus on developing cost-effective, remarkably efficient, and recyclable adsorbents to enhance water quality. In this work, a cost-effective biobased activated carbon (AC) adsorbent was synthesized from date palm bark wastes and applied for the removal of two azo dye pollutants sunset yellow (SY), and tartrazine (TZ) from wastewater. The as-prepared powder of activated carbon was fully characterized using different analytical techniques including XRD, FTIR, XPS, Raman spectroscopy, zeta potential, FESEM, pHPZC and N2 adsorption-desorption analysis. These analyses revealed that the resulting biobased AC exhibited a graphene-like layered structure with a noticeable degree of structural order, decorated with diverse surface functional groups. The highly porous structure also demonstrated significant adsorption capacity for SY, and TZ contaminants, particularly at ambient temperatures. It achieved maximum uptakes of approximately 90 mg/g, and 65 mg/g for SY, and TZ respectively, spanning a wide pH range. Moreover, in-depth studies of the adsorption process, including kinetic and thermodynamic analyses, unveiled a chemical, spontaneous, and endothermic sorption mechanism for both SY, and TZ dyes, following a pseudo-second-order model adsorption behavior on the AC structure. Finally, an accurate adsorption mechanism has been proposed for the adsorption of dyes confirmed by experiments and molecular dynamic simulations.

Experimental simulation study on influencing factors of liquid production capacity in heterogeneous water drive reservoirs

Oilfield development involves a complex, dynamic flow process of oil and water, with reservoir characteristics and environmental conditions continually evolving as the field evolves. Particularly when a waterflooding reservoir reaches a stage of ultra-high water cut, prolonged waterflooding intensifies challenges in reservoir development: the exacerbation of reservoir heterogeneity and development behaviors disrupts the initial understanding of the reservoir's liquid production capacity from current development conditions. Thus, it becomes imperative to adjust the productivity prediction methods for oil wells in heterogeneous waterflooding reservoirs. Leveraging the flow simulation of reservoir micro channel networks, and integrating features such as the geometric characteristics of the reservoir percolation field, micro channel characteristics, interlayer differences of mixed layers, degree of plane heterogeneity, production pressure differentials, and fluid properties, a visual sand filling experimental model is established that adheres to specific similarity criteria. Using this sand filling experimental model, we simulate the percolation characteristics of oil–water two-phase flow during the waterflooding process, and uncover the diverse influencing factors and their varying degrees of impact on the oil-phase flow during this waterflooding phase. Qualitative and semi-quantitative percolation simulation experiments are employed to intuitively demonstrate the interlayer interference, degree of plane heterogeneity, and oil–water distribution in heterogeneous reservoirs, which influence the change in oil well productivity during waterflooding. This lays bare the microscopic percolation mechanisms behind the productivity changes in heterogeneous waterflooding reservoirs. The simulation experiment results show that the higher the permeability, the stronger the micro-heterogeneity, and the smaller the overall mobility increase after flooding, the smaller the JLDmax obtained by testing or calculation. At the same permeability, the greater the driving pressure difference, the greater the microscopic sweep coefficient within the pore network, and the greater the mobility increase after flooding, the greater the JLDmax. There is interlayer interference in commingled mining, and the higher the permeability of the high-permeability layer (the greater the interlayer difference), the higher the initial productivity of the commingled well. However, due to the high permeability layer being prone to flooding, resulting in ineffective water circulation, the low-permeability tube is difficult to completely flood, resulting in a small increase in overall mobility, and therefore, JLDmax is small. Water drive preferentially breaks through the high permeability zone on the plane, and the shape of the water drive sweep zone is controlled by the planar permeability gradient, the width of the high permeability zone, and the displacement pressure difference.

Experimental simulation study on gas flow field in combined goaf during the transition period of coal pillar-free working face relocation

Regarding the gas disaster caused by the complex ventilation system and the changeable flow field in the combined goaf during the transition period of the coal pillar-free working face, the self-designed physical simulation test bench for the combined goaf of coal pillar-free mining was used to compare and analyze the distribution law of wind pressure, gas, and oxygen concentration field in the combined goaf during the moving period of the working face and the normal mining period. The results show that during the relocation period, the gas concentration in the stope will always be slightly higher than that in the normal mining period, and the existing air leakage channel will lead to complex air flow in the combined goaf, which is easy to cause gas explosion accidents. The formation conditions, judgment principles, and judgment methods of the dangerous area of gas explosion coupling disaster in goaf are analyzed. By changing the air distribution ratio of the main and auxiliary air intake roadways, it is concluded that the explosion area will form an “L”-shaped explosion zone in the goaf, and the area of gas explosion disaster area during the relocation period will be larger than that the normal mining period. According to the size of the gas explosion area, the optimal air distribution ratio of the main and auxiliary air intake roadway during the transition period of the working face relocation and the normal mining period is 2:1. Under this air distribution ratio, the gas explosion area is the smallest, which is 132 284 and 113 534 mm2, respectively. The research results are of great significance to reveal the mechanism of gas disaster induced by goaf during the transition period of coal pillar-free relocation.

An experimental and chemical kinetic simulation study of the high-temperature pyrolysis of linear C1–C5 alcohols

The high-temperature pyrolysis characteristics of C1–C5 linear alcohols, including methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol, systematically studied experimentally and the results interpreted using a detailed kinetic model. Specifically, a single-pulse shock tube coupled to a gas chromatography-mass spectrometry (GC-MS) system and a gas chromatograph (GC) is used to conduct a comprehensive experimental study on the high-temperature pyrolysis of the five alcohols, at pressures of 5 and 10 bar, in the temperature range 1000–1800 K at 1% fuel diluted by argon. Qualitative and quantitative analyses are conducted on the reactant, intermediate, and product species involved to determine species distributions as a function of temperature. A detailed chemical kinetic mechanism, NUIGMech1.3, is used to simulate the experimental data under the working conditions. The simulation results are compared with the experimental results, and it is shown that the overall trends between experiments and model predictions are relatively ideal in the comparison of all product and reactant concentrations, even though there is still a phenomenon of inaccurate prediction. Reaction pathway analysis is then conducted on the five alcohols. The present work not only provides additional experimental data for alcohols, but also provides insights into the high-temperature pyrolysis characteristics of the five fuels, which will be valuable for further development and optimization of detailed kinetic mechanisms of these alcohols and promote their practical application.

Experimental and numerical studies on hydrogen leakage and dispersion evolution characteristics in space with large aspect ratios

Green hydrogen is a clean energy, and its application scenarios have become increasingly diverse with the development of hydrogen energy equipment. To ensure the safe use of hydrogen, it is essential to study the leakage and dispersion characteristics of hydrogen in different spaces. In this work, the experimental and numerical simulation studies on hydrogen leakage and dispersion were conducted in spaces with large aspect ratios. The research found that hydrogen leakage and dispersion can be divided into three typical stages: buoyancy-dominated stage, horizontal spreading stage, and vertical filling stage. The relationship between the concentration rise rate of hydrogen and the leakage rate and leakage direction in the third stage is established. As the leakage speed increases, the dispersion time of hydrogen decreases, leading to significant differences in concentration distribution. Changes in the leakage direction will influence the interaction between hydrogen and the walls, subsequently altering the dispersion behavior of hydrogen. Changes in leakage speed and direction do not affect the sequence of hydrogen dispersion to specific points in space. Based on the characteristics of hydrogen dispersion, a subjective-objective integrated hydrogen weighted concentration calculation method was proposed in this study. The hydrogen weighted concentration can be effectively characterized the leakage and dispersion characteristics of hydrogen. The value always approaches 50% of the average concentration, which can be used for determining the warning threshold or specifying emergency strategies.