Pub Date : 2024-09-29DOI: 10.1016/j.jlp.2024.105448
In the study of flame quenching, quenching thickness is one of the important parameters to determine the design of a flame arrester, and often determines the flame quenching performance of the arrester. In the study, residual network (ResNet) and artificial neural network (ANN) are used to predict the critical quench thickness of combustible gas in pipelines. The critical quench thickness is influenced by fuel concentration and density, pipeline size, inert gas type and concentration, porous media porosity, and thermal conductivity. The influence of different combinations of hyper-parameters on the prediction performance of the two models is explored. The results show that the prediction performance of both models reaches the best after hyper-parameter optimization. Compared with ANN, the ResNet model shows more stable and better prediction ability, and its optimal evaluation parameters are: MAE is 1.4679, MSE is 91.7431, R2 is 0.9216. The prediction errors of the two models on the same dataset are subjected to analysis, and the impact of the use of normalized data on the performance of the two models is compared. It is determined that the ResNet model demonstrated superior robustness and generalization ability in predicting the critical quenching thickness of combustible gases. The study is helpful for the safety protection of combustible gas and the safety design of pipeline arresters.
{"title":"Predicting critical flame quenching thickness using machine learning approach with ResNet and ANN","authors":"","doi":"10.1016/j.jlp.2024.105448","DOIUrl":"10.1016/j.jlp.2024.105448","url":null,"abstract":"<div><div>In the study of flame quenching, quenching thickness is one of the important parameters to determine the design of a flame arrester, and often determines the flame quenching performance of the arrester. In the study, residual network (ResNet) and artificial neural network (ANN) are used to predict the critical quench thickness of combustible gas in pipelines. The critical quench thickness is influenced by fuel concentration and density, pipeline size, inert gas type and concentration, porous media porosity, and thermal conductivity. The influence of different combinations of hyper-parameters on the prediction performance of the two models is explored. The results show that the prediction performance of both models reaches the best after hyper-parameter optimization. Compared with ANN, the ResNet model shows more stable and better prediction ability, and its optimal evaluation parameters are: MAE is 1.4679, MSE is 91.7431, R<sup>2</sup> is 0.9216. The prediction errors of the two models on the same dataset are subjected to analysis, and the impact of the use of normalized data on the performance of the two models is compared. It is determined that the ResNet model demonstrated superior robustness and generalization ability in predicting the critical quenching thickness of combustible gases. The study is helpful for the safety protection of combustible gas and the safety design of pipeline arresters.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-28DOI: 10.1016/j.jlp.2024.105447
The population distribution within areas potentially impacted by major accidents is crucial for societal risk analysis. Population data are essential for land use planning activities related to major accident hazards. However, repeated quantitative risk assessments (QRA) and diverse planning scenarios complicate planning decisions in Major Hazard Installation (MHI) areas. This study introduces an analysis method for the safety of population distribution in potential impact zones of major accidents. By combining accident simulation and population distribution characteristics analysis, we established standardized indicators that succinctly indicate safety thresholds for societal risks, addressing the challenge of rapidly assessing off-site population safety. A rapid formula meeting practical needs is provided for urban managers and planners, enabling them to easily evaluate how population density and distribution affect societal risks in MHI areas. Finally, we applied this method to the flammable and explosive hazardous material enterprises in Shijiazhuang, China, demonstrating its functionality and practicality. The application results suggest its potential as a useful decision-support method for guiding urban planning and emergency management. This work offers new insights and valuable demonstrations for enhancing vulnerability and land use risk assessments in MHI regions.
{"title":"A rapid analysis method for regional population distribution safety based on societal risk assessment","authors":"","doi":"10.1016/j.jlp.2024.105447","DOIUrl":"10.1016/j.jlp.2024.105447","url":null,"abstract":"<div><div>The population distribution within areas potentially impacted by major accidents is crucial for societal risk analysis. Population data are essential for land use planning activities related to major accident hazards. However, repeated quantitative risk assessments (QRA) and diverse planning scenarios complicate planning decisions in Major Hazard Installation (MHI) areas. This study introduces an analysis method for the safety of population distribution in potential impact zones of major accidents. By combining accident simulation and population distribution characteristics analysis, we established standardized indicators that succinctly indicate safety thresholds for societal risks, addressing the challenge of rapidly assessing off-site population safety. A rapid formula meeting practical needs is provided for urban managers and planners, enabling them to easily evaluate how population density and distribution affect societal risks in MHI areas. Finally, we applied this method to the flammable and explosive hazardous material enterprises in Shijiazhuang, China, demonstrating its functionality and practicality. The application results suggest its potential as a useful decision-support method for guiding urban planning and emergency management. This work offers new insights and valuable demonstrations for enhancing vulnerability and land use risk assessments in MHI regions.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-28DOI: 10.1016/j.jlp.2024.105444
The fire situation has gotten worse over the past few years. To put out flames, we desperately need more effective and sustainable fire extinguishing products. The primary goal of this research is to increase the dry water (DW) core-shell structure's stability and water retention—but more significantly, to increase the structure's fire extinguishing effectiveness. The following five materials are introduced in this article: dimethyl silicone oil, lauryl ether phosphate ester (AEO-3P), gelled adhesive, gallium bicarbonate (Ca(HCO3)2), and magnesium bicarbonate (Mg(HCO3)2). The water content of DW increased to 88%–94% with the addition of gel and dimethyl silicone oil, according to thermogravimetric analysis and moisture retention tests. By altering the characteristics of the liquid-solid interface between the hydrophobic silica and the aqueous solution, lauryl ether phosphate increased the stability of the DW structure. This study also examined and contrasted the effectiveness of five commercial dry powder fire extinguishing agents and DW fire extinguishing agents in terms of fire extinguishing efficiency. The findings indicate that the Mg(HCO3)2 gel DW extinguishing time in n-heptane fire is the smallest (9 s), while the Ca(HCO3)2 gel DW extinguishing time in anhydrous ethanol fire is the shortest (9 s). The extinguishing efficiency of the two is boosted by 66% and 55%, respectively, in comparison to commercial dry powder. By developing a new kind of stable, effective, and non-toxic fire extinguishing chemical, this work has benefited the firefighting and rescue sectors.
{"title":"Efficacy evaluation of bicarbonate formulations dry water fire extinguishing agents","authors":"","doi":"10.1016/j.jlp.2024.105444","DOIUrl":"10.1016/j.jlp.2024.105444","url":null,"abstract":"<div><div>The fire situation has gotten worse over the past few years. To put out flames, we desperately need more effective and sustainable fire extinguishing products. The primary goal of this research is to increase the dry water (DW) core-shell structure's stability and water retention—but more significantly, to increase the structure's fire extinguishing effectiveness. The following five materials are introduced in this article: dimethyl silicone oil, lauryl ether phosphate ester (AEO-3P), gelled adhesive, gallium bicarbonate (Ca(HCO<sub>3</sub>)<sub>2</sub>), and magnesium bicarbonate (Mg(HCO<sub>3</sub>)<sub>2</sub>). The water content of DW increased to 88%–94% with the addition of gel and dimethyl silicone oil, according to thermogravimetric analysis and moisture retention tests. By altering the characteristics of the liquid-solid interface between the hydrophobic silica and the aqueous solution, lauryl ether phosphate increased the stability of the DW structure. This study also examined and contrasted the effectiveness of five commercial dry powder fire extinguishing agents and DW fire extinguishing agents in terms of fire extinguishing efficiency. The findings indicate that the Mg(HCO<sub>3</sub>)<sub>2</sub> gel DW extinguishing time in n-heptane fire is the smallest (9 s), while the Ca(HCO<sub>3</sub>)<sub>2</sub> gel DW extinguishing time in anhydrous ethanol fire is the shortest (9 s). The extinguishing efficiency of the two is boosted by 66% and 55%, respectively, in comparison to commercial dry powder. By developing a new kind of stable, effective, and non-toxic fire extinguishing chemical, this work has benefited the firefighting and rescue sectors.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-28DOI: 10.1016/j.jlp.2024.105445
The explosion process of 150 nm polymethyl methacrylate (PMMA) dust in the interconnected vessels is studied through CFD, which supports the safety protection of the powder-related industry. The simulation results are verified by the overpressure and the flame propagation velocity, which are in excellent agreement with the experimental results and have high reliability. The results show that with the expansion in the pipe diameter, the turbulent velocity in the primary vessel decreases while the precompression increases. With the growth of the volume ratio, the maximum explosion overpressure decreases first and then mounts after reaching the trough. For industrial explosion-proof design, it should be avoided to use pipe diameters for the most dangerous conditions. The existence of an optimal volume ratio is the optimal choice for explosion-proof designs. This study supports an in-depth understanding of the evolution mechanism of pressure-piling in interconnected vessels and contributes effective methods for designing equipment with explosion risk.
{"title":"Effect of pipe diameter and volume ratio on dust explosion in interconnected vessels","authors":"","doi":"10.1016/j.jlp.2024.105445","DOIUrl":"10.1016/j.jlp.2024.105445","url":null,"abstract":"<div><div>The explosion process of 150 nm polymethyl methacrylate (PMMA) dust in the interconnected vessels is studied through CFD, which supports the safety protection of the powder-related industry. The simulation results are verified by the overpressure and the flame propagation velocity, which are in excellent agreement with the experimental results and have high reliability. The results show that with the expansion in the pipe diameter, the turbulent velocity in the primary vessel decreases while the precompression increases. With the growth of the volume ratio, the maximum explosion overpressure decreases first and then mounts after reaching the trough. For industrial explosion-proof design, it should be avoided to use pipe diameters for the most dangerous conditions. The existence of an optimal volume ratio is the optimal choice for explosion-proof designs. This study supports an in-depth understanding of the evolution mechanism of pressure-piling in interconnected vessels and contributes effective methods for designing equipment with explosion risk.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.jlp.2024.105438
<div><div>In order to inhibit the coal-oxygen complex that triggers spontaneous coal combustion, a retardant consisting of sodium alginate solution, sodium bicarbonate, inorganic salt MgCl<sub>2</sub> and deoxidiser that can achieve multiple effects of hysteresis and oxygen depletion was developed. Taking the sulfur-containing side-chain reactive group of coal molecule -CH<sub>2</sub>-SH as the object of study, the Gaussian 16W procedure and density-functional-transfer theory (DFT) were applied to investigate the electrostatic potential and reaction tendency, oxygen adsorption capacity, front-line orbitals, natural bonding capacity, and oxygen adsorption capacity of the reactive group before and after the formation of the complexes with Na<sup>+</sup> and Mg<sup>2+</sup>, using the solvation effect at the level of B3LYP/6-31G(d, p), respectively. The changes of electrostatic potential and reaction tendency, oxygen adsorption, front orbitals, natural bonding orbitals and charge transfer before and after the formation of complexes between -CH<sub>2</sub>-SH reactive groups and Na<sup>+</sup>, Mg<sup>2+</sup>, respectively. Comparative analysis of the interaction with oxygen before and after the formation of coordination blocking structure of coal and inorganic salts in gaseous environment, aqueous environment and retarded oxygen-depleting sodium alginate blocking solution environment, respectively. The calculated results show that the side chain of the aromatic ring of the raw coal is the active site for easy adsorption of oxygen, and the stability of the coordination blocking structure is significantly enhanced under the environment of hysteretic oxygen-depleting sodium alginate gel blocking agent, and the adsorption of oxygen before and after the coal molecule combines with Na<sup>+</sup> and Mg<sup>2+</sup> is the weakest under the environment of hysteretic oxygen-depleting sodium alginate gel blocking agent; The absolute value of the HOMO orbital energy increases the most, and the energy level difference (E<sub>LUMO</sub> - E<sub>HOMO</sub>) of the complexes increases the most; the natural bonding orbital analysis reveals that the lone pair of electrons of S atoms in -CH<sub>2</sub>-SH under the environment of hysteresis oxygen depletion sodium alginate gel blocker has a strong coordination effect with Na<sup>+</sup> and Mg<sup>2+</sup>. In the hysteresis oxygen depletion sodium alginate gel resist environment, the stability of the coordination blocking structure is strengthened due to the moderateness of the dielectric constant, and its oxygen depletion also reduces the number of O<sub>2</sub> molecules, which further reduces the adsorption and collision chances between the two, and a more desirable blocking effect can be obtained. The results reveal the micro-mechanism of the hysteresis oxygen depletion inhibitor in preventing spontaneous combustion of coal, which can provide a reference for further improving the inhibition effect of the inhi
{"title":"Microscopic mechanism of oxygen consumption inhibitor delaying the oxidation of coal","authors":"","doi":"10.1016/j.jlp.2024.105438","DOIUrl":"10.1016/j.jlp.2024.105438","url":null,"abstract":"<div><div>In order to inhibit the coal-oxygen complex that triggers spontaneous coal combustion, a retardant consisting of sodium alginate solution, sodium bicarbonate, inorganic salt MgCl<sub>2</sub> and deoxidiser that can achieve multiple effects of hysteresis and oxygen depletion was developed. Taking the sulfur-containing side-chain reactive group of coal molecule -CH<sub>2</sub>-SH as the object of study, the Gaussian 16W procedure and density-functional-transfer theory (DFT) were applied to investigate the electrostatic potential and reaction tendency, oxygen adsorption capacity, front-line orbitals, natural bonding capacity, and oxygen adsorption capacity of the reactive group before and after the formation of the complexes with Na<sup>+</sup> and Mg<sup>2+</sup>, using the solvation effect at the level of B3LYP/6-31G(d, p), respectively. The changes of electrostatic potential and reaction tendency, oxygen adsorption, front orbitals, natural bonding orbitals and charge transfer before and after the formation of complexes between -CH<sub>2</sub>-SH reactive groups and Na<sup>+</sup>, Mg<sup>2+</sup>, respectively. Comparative analysis of the interaction with oxygen before and after the formation of coordination blocking structure of coal and inorganic salts in gaseous environment, aqueous environment and retarded oxygen-depleting sodium alginate blocking solution environment, respectively. The calculated results show that the side chain of the aromatic ring of the raw coal is the active site for easy adsorption of oxygen, and the stability of the coordination blocking structure is significantly enhanced under the environment of hysteretic oxygen-depleting sodium alginate gel blocking agent, and the adsorption of oxygen before and after the coal molecule combines with Na<sup>+</sup> and Mg<sup>2+</sup> is the weakest under the environment of hysteretic oxygen-depleting sodium alginate gel blocking agent; The absolute value of the HOMO orbital energy increases the most, and the energy level difference (E<sub>LUMO</sub> - E<sub>HOMO</sub>) of the complexes increases the most; the natural bonding orbital analysis reveals that the lone pair of electrons of S atoms in -CH<sub>2</sub>-SH under the environment of hysteresis oxygen depletion sodium alginate gel blocker has a strong coordination effect with Na<sup>+</sup> and Mg<sup>2+</sup>. In the hysteresis oxygen depletion sodium alginate gel resist environment, the stability of the coordination blocking structure is strengthened due to the moderateness of the dielectric constant, and its oxygen depletion also reduces the number of O<sub>2</sub> molecules, which further reduces the adsorption and collision chances between the two, and a more desirable blocking effect can be obtained. The results reveal the micro-mechanism of the hysteresis oxygen depletion inhibitor in preventing spontaneous combustion of coal, which can provide a reference for further improving the inhibition effect of the inhi","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25DOI: 10.1016/j.jlp.2024.105441
Acquiring and visualizing temperature data in real time in the event of a fire in an electrical and mechanical equipment room is of great significance. It can be applied to early fire detection and monitoring, help rescuers quickly understand the fire situation, develop effective fire extinguishing and evacuation plans, and provide valuable data support for subsequent accident investigation. Acoustic computed tomography (CT) temperature measurement technology has the benefits of high precision, non-contact, real-time and global, in order to explore the applicability of this technology in the acquisition of details about temperature in the fire scene of electrical and mechanical equipment room, this paper carries out the following research. A numerical model of the fire in the electrical and mechanical equipment room is constructed on the basis of fire dynamics simulator (FDS), and the basic temperature data is obtained. The large ill-conditioned matrix equation of acoustic flight is constructed under a variety of mesh division schemes, and the Simultaneous Algebraic Reconstruction Technique (SART) is used to figure it out. Then we accomplish the temperature field reconstruction of the electrical and mechanical equipment room in different fire stages. The effect of reconstruction is evaluated through the analysis of the difference between the original and rebuilt data. The conclusions demonstrate that the acoustic CT temperature measurement technique can achieve reconstructing the temperature field in real time and with accuracy under the appropriate reconstruction scheme. With the rise in the quantity of grid divisions, the morphology of the reconstructed high-temperature region of the fire field is more similar to the morphology of the basic fire field within a certain range.
{"title":"Reconstruction of temperature field in different fire stages of electrical and mechanical equipment room based on acoustic CT","authors":"","doi":"10.1016/j.jlp.2024.105441","DOIUrl":"10.1016/j.jlp.2024.105441","url":null,"abstract":"<div><div>Acquiring and visualizing temperature data in real time in the event of a fire in an electrical and mechanical equipment room is of great significance. It can be applied to early fire detection and monitoring, help rescuers quickly understand the fire situation, develop effective fire extinguishing and evacuation plans, and provide valuable data support for subsequent accident investigation. Acoustic computed tomography (CT) temperature measurement technology has the benefits of high precision, non-contact, real-time and global, in order to explore the applicability of this technology in the acquisition of details about temperature in the fire scene of electrical and mechanical equipment room, this paper carries out the following research. A numerical model of the fire in the electrical and mechanical equipment room is constructed on the basis of fire dynamics simulator (FDS), and the basic temperature data is obtained. The large ill-conditioned matrix equation of acoustic flight is constructed under a variety of mesh division schemes, and the Simultaneous Algebraic Reconstruction Technique (SART) is used to figure it out. Then we accomplish the temperature field reconstruction of the electrical and mechanical equipment room in different fire stages. The effect of reconstruction is evaluated through the analysis of the difference between the original and rebuilt data. The conclusions demonstrate that the acoustic CT temperature measurement technique can achieve reconstructing the temperature field in real time and with accuracy under the appropriate reconstruction scheme. With the rise in the quantity of grid divisions, the morphology of the reconstructed high-temperature region of the fire field is more similar to the morphology of the basic fire field within a certain range.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25DOI: 10.1016/j.jlp.2024.105435
In semi-open space, obstacles have the potential to accelerate flame propagation and increase hydrogen-air deflagration pressure. Therefore, this paper is dedicated to exploring the influence of obstacles on the premixed hydrogen deflagration, which is crucial for enhancing the safety of industrial production and energy utilization. By using Large Eddy Simulation (LES) model in OpenFOAM, this study investigates the deflagration characteristics of premixed hydrogen in the presence of three different shaped obstacles. The analysis results reveal that under obstacle conditions, the flame shape can be categorized into four phases: the hemispherical phase, finger-shaped phase, jet phase, and vortex phase. The velocity of the flame front is nearly same for elliptical and rectangular obstacle condition, but it is 36% higher compared to triangular obstacle condition. The impact of triangular and rectangular obstacles on explosion overpressure is less than that of triangular obstacles on explosion overpressure, but it is 16% higher than that of elliptical obstacle. Analyzing the vorticity generated by different obstacle reveals that the vorticity produced by rectangular obstacle is twice as much as that produced by elliptical obstacle, whereas the vorticity produced by triangular obstacle is 2.4 times greater than that produced by elliptical obstacle. The acceleration of hydrogen-air explosion process occurs due to the narrow space created by obstacle and pipeline walls, and the shape of obstacle significantly influences this acceleration.
{"title":"Study on the hydrogen-air premixed flame propagation characteristics in semi-open space with obstacle","authors":"","doi":"10.1016/j.jlp.2024.105435","DOIUrl":"10.1016/j.jlp.2024.105435","url":null,"abstract":"<div><div>In semi-open space, obstacles have the potential to accelerate flame propagation and increase hydrogen-air deflagration pressure. Therefore, this paper is dedicated to exploring the influence of obstacles on the premixed hydrogen deflagration, which is crucial for enhancing the safety of industrial production and energy utilization. By using Large Eddy Simulation (LES) model in OpenFOAM, this study investigates the deflagration characteristics of premixed hydrogen in the presence of three different shaped obstacles. The analysis results reveal that under obstacle conditions, the flame shape can be categorized into four phases: the hemispherical phase, finger-shaped phase, jet phase, and vortex phase. The velocity of the flame front is nearly same for elliptical and rectangular obstacle condition, but it is 36% higher compared to triangular obstacle condition. The impact of triangular and rectangular obstacles on explosion overpressure is less than that of triangular obstacles on explosion overpressure, but it is 16% higher than that of elliptical obstacle. Analyzing the vorticity generated by different obstacle reveals that the vorticity produced by rectangular obstacle is twice as much as that produced by elliptical obstacle, whereas the vorticity produced by triangular obstacle is 2.4 times greater than that produced by elliptical obstacle. The acceleration of hydrogen-air explosion process occurs due to the narrow space created by obstacle and pipeline walls, and the shape of obstacle significantly influences this acceleration.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-23DOI: 10.1016/j.jlp.2024.105440
The explosiveness of hazardous materials determines that once an accident occurs during transportation, severe damage will be imposed on surrounding targets. However, the increasing complexity of the road network significantly augments the risk of damage occurrence. To maintain low accident risks in transporting hazardous materials, this study proposes a method for selection and planning of transportation routes based on explosion accident risks. Firstly, the road network topology is associated with vehicle status to establish a relationship between the accident probability and speed gradient. Meanwhile, an independent grid-based approach is used to perform multi-level damage quantification on various objects. Secondly, route risks are quantitatively characterized, and a comparison system for multiple risk metrics is established. Based on search algorithms, route planning and risk ranking are achieved. Finally, the method is validated. It has been confirmed that this method can quickly and accurately obtain route ranking and risk distribution. The results offer practical guidance for relevant organizations to improve risk management and strategy development, and provide reference for future research.
{"title":"Selection and planning of hazardous materials transportation routes based on explosion accident risks","authors":"","doi":"10.1016/j.jlp.2024.105440","DOIUrl":"10.1016/j.jlp.2024.105440","url":null,"abstract":"<div><div>The explosiveness of hazardous materials determines that once an accident occurs during transportation, severe damage will be imposed on surrounding targets. However, the increasing complexity of the road network significantly augments the risk of damage occurrence. To maintain low accident risks in transporting hazardous materials, this study proposes a method for selection and planning of transportation routes based on explosion accident risks. Firstly, the road network topology is associated with vehicle status to establish a relationship between the accident probability and speed gradient. Meanwhile, an independent grid-based approach is used to perform multi-level damage quantification on various objects. Secondly, route risks are quantitatively characterized, and a comparison system for multiple risk metrics is established. Based on search algorithms, route planning and risk ranking are achieved. Finally, the method is validated. It has been confirmed that this method can quickly and accurately obtain route ranking and risk distribution. The results offer practical guidance for relevant organizations to improve risk management and strategy development, and provide reference for future research.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-23DOI: 10.1016/j.jlp.2024.105442
Low oxygen at a coal mine's working face has a detrimental impact on working conditions and productivity. This study conducted an experiment on oxygen consumption at low temperatures, quantified the rate of air infiltration, and scrutinised and examined the zoning division of coal seam gas occurrences. The gas change rules in the return air corner and the goaf and the gas outflow rules in the goaf to the working face are analysed. Experiment results reveal that residual coal predominantly consumes oxygen through a combination of physical adsorption and chemical reaction, which is the key factor in the decrease in oxygen concentration. The examination showed, that the gas emission rate of air from the surface cracks to the working face is 0.09–0.13 m·s−1. Air leakage in the goaf results in the oxidation of residual coal and consequently leads to significant oxygen consumption. The release of low-oxygen gases from the oxidation of residual coal in the goaf to the working face is facilitated by atmospheric pressure and negative pressure ventilation methods, which act as sources of power. The research findings offer direction for examining and managing the problem of low oxygen in coal mine working faces.
{"title":"Effects of oxygen consumption characteristics of goaf on the low oxygen formation mechanism in the working face","authors":"","doi":"10.1016/j.jlp.2024.105442","DOIUrl":"10.1016/j.jlp.2024.105442","url":null,"abstract":"<div><div>Low oxygen at a coal mine's working face has a detrimental impact on working conditions and productivity. This study conducted an experiment on oxygen consumption at low temperatures, quantified the rate of air infiltration, and scrutinised and examined the zoning division of coal seam gas occurrences. The gas change rules in the return air corner and the goaf and the gas outflow rules in the goaf to the working face are analysed. Experiment results reveal that residual coal predominantly consumes oxygen through a combination of physical adsorption and chemical reaction, which is the key factor in the decrease in oxygen concentration. The examination showed, that the gas emission rate of air from the surface cracks to the working face is 0.09–0.13 m·s<sup>−1</sup>. Air leakage in the goaf results in the oxidation of residual coal and consequently leads to significant oxygen consumption. The release of low-oxygen gases from the oxidation of residual coal in the goaf to the working face is facilitated by atmospheric pressure and negative pressure ventilation methods, which act as sources of power. The research findings offer direction for examining and managing the problem of low oxygen in coal mine working faces.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-22DOI: 10.1016/j.jlp.2024.105437
Process systems are sensitive and vital industrial facilities. Disturbances in their performance may cause harm to the environment,humans,or significant economic damage. In risk assessment of chemical process industries, the available data, information, and knowledge are typically rare, limited, and often unrealistic. This issue poses a challenge to conducting a credible quantitative risk assessment and effects the robustness of the results. To address these challenges, this work proposes a methodology based on the Dempster-Shafer theory of evidence as the reasoning framework. It incorporates risk identification, analysis, and mitigation phases to ensure a thorough analysis of risks and the integration of proactive risk reduction strategies. The approach aims to model the worst-case hazard scenario and assess associated risks using various methods such as FMECA, Bow-Tie, Credal Network, and Dempster-Shafer theory. The proposed approach models imprecision and data ambiguity using intervals and associated belief mass. This extension provides a basis for addressing the fundamental problem of prior ignorance about the distribution of the observed data, which is prevalent in data mining applications. A new approach is proposed that utilizes Belief and Plausibility curves, similar to a Cumulative Distribution Function, to propagate uncertainty, enhance criticality discrimination, and determine cumulated belief measures. This approach is applied in analyzing the failure modes identified in FMECA and is further extended through the credal network for comprehensive risk assessment. Results show how to express irrelevant and independent judgments, and how to work out with inferences in credal networks. This issue is often overlooked, but if properly addressed it represents the key to ultimately drawing reliable conclusions and fully utilizing the system's available data. A case study of the City Gate Station system was used to verify the application potential of the proposed approach.
{"title":"A risk assessment of a gas pressure reduction station system with confidence for dealing with imprecisions and unknowns","authors":"","doi":"10.1016/j.jlp.2024.105437","DOIUrl":"10.1016/j.jlp.2024.105437","url":null,"abstract":"<div><div>Process systems are sensitive and vital industrial facilities. Disturbances in their performance may cause harm to the environment,humans,or significant economic damage. In risk assessment of chemical process industries, the available data, information, and knowledge are typically rare, limited, and often unrealistic. This issue poses a challenge to conducting a credible quantitative risk assessment and effects the robustness of the results. To address these challenges, this work proposes a methodology based on the Dempster-Shafer theory of evidence as the reasoning framework. It incorporates risk identification, analysis, and mitigation phases to ensure a thorough analysis of risks and the integration of proactive risk reduction strategies. The approach aims to model the worst-case hazard scenario and assess associated risks using various methods such as FMECA, Bow-Tie, Credal Network, and Dempster-Shafer theory. The proposed approach models imprecision and data ambiguity using intervals and associated belief mass. This extension provides a basis for addressing the fundamental problem of prior ignorance about the distribution of the observed data, which is prevalent in data mining applications. A new approach is proposed that utilizes Belief and Plausibility curves, similar to a Cumulative Distribution Function, to propagate uncertainty, enhance criticality discrimination, and determine cumulated belief measures. This approach is applied in analyzing the failure modes identified in FMECA and is further extended through the credal network for comprehensive risk assessment. Results show how to express irrelevant and independent judgments, and how to work out with inferences in credal networks. This issue is often overlooked, but if properly addressed it represents the key to ultimately drawing reliable conclusions and fully utilizing the system's available data. A case study of the City Gate Station system was used to verify the application potential of the proposed approach.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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