24 results on '"fire source location"'
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2. Study on radon gas transport law of overlying rock layer under different geological conditions of coal spontaneous combustion.
- Author
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Dong, Kaili, Zhou, Bin, Zhang, Yulong, Lu, Zhifan, Liu, Xiaoyuan, and Wang, Junfeng
- Subjects
- *
RADON detectors , *SPONTANEOUS combustion , *COAL combustion , *COMBUSTION engineering , *COAL mining - Abstract
The alpha cup method was employed to delineate spontaneous combustion areas in three coal mines. Following this, cores were drilled to measure radon concentration at various depths using the RAD7 radon detector. Subsequently, the results were then combined with the equation of radon concentration distribution with depth in a semi-infinite medium, demonstrating the equation's suitability for shallow coal seams. Thereafter, numerical models of radon migration were constructed. The study found that the upward migration of radon is weakened and adsorbed by rock formations, and faults, altering the migration path of radon. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. Experimental investigation on effect of fire source location on compartment fire phenomena with a single natural ceiling vent.
- Author
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Park, Min Yeong and Lee, Chi Young
- Subjects
HEAT release rates ,TEMPERATURE distribution ,FIRE investigation ,LOW temperatures ,CEILINGS - Abstract
The effect of fire source location (FSL) on compartment fire phenomena with a single natural ceiling vent was experimentally investigated under various vent area (VA) and heat release rate (HRR) conditions. Two FSL cases, where the fire source was located at the centre (FSL
C ) and on the side (FSLS ) of the floor, were tested. In the bidirectional vent flow patterns of FSLC and FSLS , the detailed locations where the smoke outflow and the fresh air inflow occurred were different. Empirical correlations were proposed for predicting the smoke outflow areas. FSLC exhibited a higher central velocity of the outflow, larger estimated mass flow rate of the outflow, and lower temperatures inside the compartment than FSLS . The estimated mass flow rate of the outflow depended more on VA than on HRR. A previous correlation was more suitable for FSLS than FSLC in predicting the mass flow rate of the outflow. [ABSTRACT FROM AUTHOR]- Published
- 2024
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4. Study on the influence of fire source location on cable tunnel detection and alarm system
- Author
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Lei Lei, Zeyu Wang, and Zihao Liang
- Subjects
Cable tunnel ,Fire source location ,Intelligent active suction detection method ,Response time ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In order to study the fire detection method of cable tunnel. We carried out physical experiments in the cable tunnel test section, using the heater pyrolyze PVC so that its pyrolysis as the ignition source obtained a total of 17 fire source location points in the horizontal and vertical directions of seven different fire detectors, and only processed the response time data of the alarm detector obtained the response time and the analysis results were drawn. With the increase of the distance from the fire source, the response time of each type of detector increases in different forms. It is found that the detection distance of the grating fiber temperature sensor is shorter, and the response time near the fire source is more stable. The detection performance of the point pyrolytic particle detector is more affected by the detection distance, which is advantageous for the detection point to have better response performance. The intelligent active suction detector is also affected by the detection distance, which is less affected than the point detector, the response time curve is more stable, and the detection performance is better at each test point. Clc number: X Document Identification Code; A.
- Published
- 2024
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5. Modelling the Smoke Flow Characteristics of a Comprehensive Pipe Gallery Fire with Rectangular Section.
- Author
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Wang, Xu, Yao, Zhilan, Wang, Yanru, Kong, Xianzhen, and Lv, Zhengxiu
- Subjects
FIRE prevention ,PREDICTION models ,COMPUTER simulation ,AIR flow ,CEILINGS - Abstract
In this study, a numerical model of the cable cabin of a comprehensive pipe gallery was established to study the smoke flow diffusion behaviour of a comprehensive pipe gallery fire under a rectangular cross-section. The effects of fire source power (Q = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 MW) and fire source location (D = 10, 20, 40, 50, 60, 80, 100 m) on the smoke flow characteristics—such as smoke layer height and thickness, longitudinal airflow velocity, and ceiling temperature distribution—were analysed, and the corresponding prediction model was fitted. The results show the following: (1) The height of the smoke layer decreases with increasing fire power, and the predictive model of the smoke layer thickness obtained from the fitting is proportional to the smoke mass flow rate and inversely proportional to the aspect ratio of the pipe gallery. (2) Longitudinal air velocity prediction models of D < 50 m and D ≥ 50 m are fitted, and the average error between them and the numerical simulation values is 9.611%. (3) The temperature decay gradient of the smoke decreases gradually with increasing distance from the fire source, while there is a significant temperature difference between the two sides of the fire source. The average relative errors of the dimensionless temperature rise models fitted upstream and downstream of the fire source in the form of Δ T T 0 = A e B D − X H + C exponentials with respect to the numerical simulations were 11.688% and 7.296%, respectively. The results of the study can provide a reference for smoke flow and fire prevention and control in comprehensive pipe galleries. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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6. Study on the smoke mass flow in T-shaped tunnel fire
- Author
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Xuming Li, Guoqing Zhu, and Lu He
- Subjects
Branched tunnel ,Smoke mass flow ,Bifurcation angle ,Fire source location ,Tunnel section size ,Heat release rate ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Smoke mass flow rate (SMFR) is an important factor for smoke control in tunnel fire. The presence of bifurcation structure can lead to the flow redistribution and distinctive characteristics. In the current study, a relational expression for the SMFR in branched tunnel was theoretically derived. A series of numerical simulations with Fire Dynamics Simulator(FDS) were conducted to investigate the effects of multiple factors on the smoke mass flow and validate the predictions. The results indicated that for a T-shaped tunnel, the amount of smoke flowing into the branch is mainly depends on the thickness and temperature of the incoming smoke flow from mainline, affecting by heat release rate(HRR) and tunnel section size, while the influence of the bifurcation angle and longitudinal position of fire source is unremarkable. Fairly good agreement was achieved between the predictions and simulation results. This research can be instrumental in estimating the SMFR in T-shaped tunnel fire scenarios and offer valuable insights for smoke management strategies.
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- 2024
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7. Investigation of the fire hazard of underground space fire scenarios in urban metro tunnels under natural ventilation: Analysis of the impact of tunnel slope on smoke back-layering length.
- Author
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Su, Zhihe, Li, Yanfeng, Zhong, Hua, Li, Junmei, Yang, Shi, Du, Tianmei, and Huang, Youbo
- Subjects
SUBWAY tunnels ,HEAT release rates ,TUNNELS ,NATURAL ventilation ,UNDERGROUND areas - Abstract
The smoke back-layering length is a crucial parameter for evacuating people in both road and subway tunnel fires. This study investigates the fire hazard induced by carriage fire in inclined metro tunnels under natural ventilation. The parameter 'transition slope' is defined to measure the smoke flow from the carriage head in the upstream direction to the tunnel or not due to the stack effect of the tunnel slope. The aim of this paper is to analyse the effects of changes in cross-section, downstream length, tunnel slope, and carriage side-door coupling on smoke behaviour characteristics by experiment and simulation methods. A piecewise function expression between dimensionless smoke back-layering length, downstream length, and tunnel slope for carriage fires in an inclined tunnel under natural ventilation is proposed by theoretical analysis. At the same time, a 1:15 scale model experiment was conducted to initially analyse the characteristics of smoke movement. Following this, full-scale numerical simulations were employed to complement the model experiment and quantify the principles governing smoke movement. The experimental results show that the tunnel slope has a significant effect on the smoke back-layering length. In contrast, the influence of the heat release rate was found to be relatively minor. In addition, simulation results show that the tunnel slope has no significant effect on the smoke back-layering length when the fire location is approximately 20 m from the train head, and the tunnel slope is in the range of 2.29° ∼ 3.43° (4% ∼ 6%). For small tunnel slopes, smoke spreads in the tunnel, and the smoke back-layering length produced by the virtual fire source shows a different law from the previous study model. Finally, the correlation coefficient of the piecewise function in theoretical analysis is fitted by combining the experimental and numerical simulation results. Practical application: This study provides valuable insights into the practical implications of controlling and mitigating the impact of fires in inclined metro tunnels. By understanding the critical role of tunnel slope and providing a quantitative tool for smoke spread law assessment, this study contributes to the enhancement of safety measures and the protection of lives in tunnel environments during fire incidents. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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8. Numerical simulation study of the influence of fire source location on parameters of external fire in tunnel
- Author
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Junliang ZHANG, Yunfei ZHU, and Xueliang ZHANG
- Subjects
exgenous fire in tunnel ,fire source location ,smoke flow ,temperature distribution ,numerical simulation ,Mining engineering. Metallurgy ,TN1-997 - Abstract
In order to study the influence of different fire source positions on fire smoke spread and fire parameters under normal ventilation, the distribution of smoke flow, temperature, and CO concentration in the tunnel under three conditions of single fire source at the roof, single fire source at the floor, and double fire sources at the roof and floor was simulated and analyzed. The results concluded that in terms of smoke thickness, the downstream settling of smoke was significant for fire at the floor and fire at both roof and floor, but no upward plume was observed for fire at the roof, and the smoke flow is more concentrated in the top. In terms of the backflow distance, the fire source in the floor is the shortest, followed by the fire source in the roof, and the fire source in the roof and the floor is the largest; the main influencing factor is the maximum smoke flow temperature difference in the roof. In terms of temperature distribution, the roof smoke flow temperature decreases with the increase of the distance from the fire source, and the fire source is located at the roof and floor at the same time. For the upper roof smoke flow temperature, the roof and floor fire is the largest and the floor fire is the smallest, while the downstream is completely opposite. In addition, the smoke flow temperature of the roof fire at 2 m height is lower than that of the other two conditions. For the CO volume fraction at the height of 2 m, the peak concentration of roof fire and floor fire appears at the front of the fire smoke, while the floor fire appears near the fire source, and the CO volume fraction upstream of the fire source is significantly higher than the latter under the former two working conditions.
- Published
- 2023
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9. Modelling the Smoke Flow Characteristics of a Comprehensive Pipe Gallery Fire with Rectangular Section
- Author
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Xu Wang, Zhilan Yao, Yanru Wang, Xianzhen Kong, and Zhengxiu Lv
- Subjects
comprehensive pipe gallery ,rectangular cross-section ,fire source power ,fire source location ,Building construction ,TH1-9745 - Abstract
In this study, a numerical model of the cable cabin of a comprehensive pipe gallery was established to study the smoke flow diffusion behaviour of a comprehensive pipe gallery fire under a rectangular cross-section. The effects of fire source power (Q = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 MW) and fire source location (D = 10, 20, 40, 50, 60, 80, 100 m) on the smoke flow characteristics—such as smoke layer height and thickness, longitudinal airflow velocity, and ceiling temperature distribution—were analysed, and the corresponding prediction model was fitted. The results show the following: (1) The height of the smoke layer decreases with increasing fire power, and the predictive model of the smoke layer thickness obtained from the fitting is proportional to the smoke mass flow rate and inversely proportional to the aspect ratio of the pipe gallery. (2) Longitudinal air velocity prediction models of D < 50 m and D ≥ 50 m are fitted, and the average error between them and the numerical simulation values is 9.611%. (3) The temperature decay gradient of the smoke decreases gradually with increasing distance from the fire source, while there is a significant temperature difference between the two sides of the fire source. The average relative errors of the dimensionless temperature rise models fitted upstream and downstream of the fire source in the form of ΔTT0=AeBD−XH+C exponentials with respect to the numerical simulations were 11.688% and 7.296%, respectively. The results of the study can provide a reference for smoke flow and fire prevention and control in comprehensive pipe galleries.
- Published
- 2024
- Full Text
- View/download PDF
10. 双层盾构隧道火灾超 380℃ 耐火极限范围研究.
- Author
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王泽军, 肖 亮, and 姜学鹏
- Abstract
Copyright of Fire Safety Science is the property of Fire Safety Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
11. Application of Solid Long-lived Radon Progeny210Po in the Location Detection of Coal Spontaneous Combustion in Goaf
- Author
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Chen LIN, Junfeng WANG, Kaili Dong, and Xuan LIU
- Subjects
coal spontaneous combustion ,fire source location ,surface detection ,radon progeny 210po ,Chemical engineering ,TP155-156 ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Technology - Abstract
Aiming at the shortcomings of isotope radon detection method, which has large workload, long period, and is easily restricted by climate and environmental factors this paper proposes the use of radon generated during the process of migration to the surface to accurately reflects the solid-state length of the cumulative value of parent radon over a period of time. Long-lived radon daughter 210Po fire detection method based on radiochemical analysis method to measure 210Po activity concentration to detect hidden mine fire areas. In order to explore the effect and accuracy of the radon progeny 210Po fire detection method in on-site detection, this paper carried out on-site experimental research in Liuwan Coal Mine where the fire source location is known. The radon gas concentration at the measuring point and the activity concentration of its solid long-lived daughter 210Po are measured. By comparing the correlation between radon gas concentration and 210Po activity concentration detection results and its influencing factors, the technology of using radon daughter 210Po to detect the location of coal spontaneous combustion in goaf is demonstrated. The results show that the radon concentration in the near-surface soil layer in the fire area has a strong correlation with the 210Po activity concentration in the overall distribution, but the 210Po activity concentration is less disturbed by external factors, and its distribution can more accurately reflect the underground coal spontaneous combustion fire area. Compared with the isotope radon detection method, the radon progeny 210Po fire detection method has higher detection accuracy, wider application range and higher application value.
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- 2023
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12. A Fire Source Localization Algorithm Based on Temperature and Smoke Sensor Data Fusion.
- Author
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Li, Lijuan, Ye, Junjie, Wang, Chenyang, Ge, Chengwen, Yu, Yuan, and Zhang, Qingwu
- Subjects
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VIDEO surveillance , *MULTISENSOR data fusion , *MACHINE learning , *TEMPERATURE sensors , *CONVOLUTIONAL neural networks , *LOCALIZATION (Mathematics) , *ALGORITHMS - Abstract
Traditional video surveillance, temperature-based or smoke-based fire source location methods are difficult to timely and accurately locate the fire source in warehouses with the characteristics of burning intensely, smoke spreading quickly, and being sheltered by shelves and goods. To overcome the drawbacks, a deep-learning-based fire source localization algorithm with temperature and smoke sensor data fusion according to the different stages of the combustion process is proposed in this paper. The temperature and smoke concentration information are collected from sensors distributed in different spatial locations of a warehouse. A convolutional neural network is used to exact the fusion data feature. The deep learning algorithm is adopted to construct the fire source localization model where the fusion data feature of temperature and smoke concentrations are the inputs and the fire source coordinates are the outputs. By using Fire Dynamics Simulator, a warehouse that meets the practical application is constructed and kinds of fire scenes are simulated. The experimental results show that the RMSE of the model localization reaches 0.63, 0.08, and 0.17 in three stages respectively, which verifies the effectiveness of the proposed fire source localization algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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13. Temperature evolution, flame traveling transition structure inside a compartment of various fire source locations.
- Author
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Sun, Xiepeng, Wang, Qiang, Lv, Jiang, Fang, Xiang, Han, Yu, Tang, Fei, and Hu, Longhua
- Subjects
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HEAT release rates , *FLAME , *FLAME temperature , *CAMCORDERS , *HIGH temperatures - Abstract
[Display omitted] • Investigated the fuel combustion behavior inside a compartment. • Observed the flame traveling behavior with fire growth for various fire source locations. • Revealed the flow dynamic conditions inside the compartment for various fire source locations. • Characterized the fire transition behavior inside compartment by two non-dimensional groups. The temperature evolution and flame traveling structure with fire growth from the fuel combustion of various source locations inside a compartment with a front opening at one end-side wall was explored in the present study. Concerning the compartment complex combustion (fire) dynamics, the temperature in a fire compartment based on the thermocouple array and the isotherm plane across the compartment center plane, flame appearance/structure obtained from the video camera and a critical heat release rate (HRR) for flame transition along the longitudinal direction of compartment were presented and discussed for a total of 329 experimental conditions. The flow dynamics conditions and combustion structures inside the compartment is presented to better interpret the experimental observation of the flame traveling/transition phenomenon. It is found that: (1) A flame traveling behavior was witnessed with increasing HRR, i.e. , the flame first moves to the inner-side and then travels to the front-wall/opening of the compartment. This behavior is also reflected by the high temperature zone. (2) The temperature in a fire compartment first rises then varies little, eventually decreases with fire growth for all burner locations. Nevertheless, the temperature at the inner-side (closer to the backwall) decreases with the burner moving from the backwall to the front-wall/opening of the compartment. The temperature at the outer-side (closer to the front-wall/opening) changes little with HRR. A dimensionless correlation was raised according to the non-dimensional fire source location. (3) The flow field inside the compartment shows a significant difference for various burner locations. The flame traveling behavior from the inner-side to the outer-side of the compartment is characterized by a critical HRR, which first increases then decreases with the burner moving from the backwall to the front-wall/opening, and increases with the opening ventilation factor. A non-dimensional correlation was proposed by two non-dimensional quantities of the critical HRR and the fire source location. These novel findings facilitate the understanding of fire dynamics concerning various fire source locations in a compartment with an opening. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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14. Temperature evolution and flame behavior inside a ceiling-vented compartment with different fire source locations under the effect of wind.
- Author
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Fang, Xiang, Zhang, Xiaolei, Ren, Fei, and Hu, Longhua
- Subjects
- *
FLAME temperature , *FROUDE number , *TRANSITION temperature , *AIR analysis , *AIR flow , *HEAT release rates - Abstract
This work presents an experimental investigation on ceiling-vented compartment fire behavior and thermal characteristics with different fire source locations under the effect of wind associated by CFD simulations. Experiments were carried out under the ambient wind condition, and the fire source was respectively set at windward side, center and leeward side. Results show that: (1) In no-wind cases, a critical heat release rate is found at which the inside temperature decreases with the increasing of fire heat release rate indicating flame flows outside. The critical HRR for fire source attached to sidewall is slightly larger than that when the fire source is located at compartment center, and it increases as vent dimension increases. (2) In ambient wind condition, there is a travelling process that the flame transfers from windward side to leeward side with the increasing of fire HRR. The critical HRR for the transition increases as vent size increases, and decreases as wind speed increases, and is basically independent of fire source location, which is proved to be related to air inflow rate. A Froude number is proposed to characterize the wind effect based on air inflow analysis, and the critical HRR for transition is represented well by the Froude number. • Ceiling-vented fire with different fire source locations under wind was studied. • Temperature profile and flame transition behavior were characterized. • Effects of wind and vent dimension on air inflow and flow field were analyzed. • Prediction model for flame transition based on the air inflow rate was proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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15. Numerical investigation on fire-induced indoor and outdoor air pollutant dispersion in an idealized urban street canyon.
- Author
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Zhao, Shengzhong, Yang, Haoran, Li, Chaorui, Obadi, Imad, Wang, Fei, Lei, Wenjun, Xu, Tiantian, and Weng, Miaocheng
- Abstract
Fire-induced pollutant dispersion under the influence of buoyancy in urban street canyons has attracted wide attention given its adverse impact on human health. This study analyzes the influences of fire source location and crossflowing wind (perpendicular to the canyon centerline) on indoor and outdoor air pollutant dispersion in an idealized urban street canyon by employing large eddy simulation. Three fire scenarios are defined according to the transverse location of the fire source: near the windward building (scenario 1), in the middle of the canyon (scenario 2), and near the leeward building (scenario 3). Results show that a re-entrainment phenomenon appears when the wind velocity reaches a critical value in scenarios 1 and 2, but it doesn't occur in scenario 3. Fire source location significantly influences the critical re-entrainment velocity. The critical velocity in scenario 1 is approximate 1.2–1.5 m/s larger than that in scenario 2. When the heat release rate is large, the critical Fr numbers are less sensitive to changes in HRR, and remain approximately constant with values of 0.47 (scenario 1) and 0.37 (scenario 2). When the wind velocity is large, more compartments are expected to be affected in the upper floors in all of the three scenarios, and smoke is distributed in an inverted triangle within the buildings. The indoor/outdoor temperature and pollutant concentrations are also analyzed. Our findings can provide valuable information for both human and property safety in relation to urban street canyons and their surrounding buildings. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
16. Predicting the Fire Source Location by Using the Pipe Hole Network in Aspirating Smoke Detection System.
- Author
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Lee, Young Man, Thien Khieu, Ha, Kim, Dong Woo, Kim, Ji Tae, and Ryou, Hong Sun
- Subjects
FIRE detectors ,SMOKE ,PIPE flow ,AIR travel ,COLD storage ,PROTECTED areas - Abstract
The aspirating smoke detector (ASD) is one of the most critical pieces of equipment for detecting smoke in a protected area when a fire occurs. It has more advantages than a conventional smoke detector because it can be used in extreme conditions, such as cold storage facilities or hot aisle containment areas. ASD uses a fan to draw air from the protected area into the pipe network system via pipe holes. The sucked air is transported into the sensing chamber to detect smoke. If the obscuration in the sensing chamber is greater than the setpoint, the ASD will sound an alarm so that people realize there is a fire. For this reason, investigating the effect of the pipe hole network on obscuration in the ASD is critical. In this study, a Pipe Hole Network Program was developed to consider the pipe flow parameter. A numerical study based on the program and an experimental study was performed. The results showed that the numerical results had the same trend as the experimental study. The further the location of the fire source was, the lower the obscuration was. In addition, the correlation between the obscuration parameter and the fire source distance was also derived. It could be used to predict the fire source location in the aspirating smoke detection system. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
17. Research on methods of mine fire monitoring and trend predictio
- Author
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SUN Jiping and SUN Yanyu
- Subjects
mine fire ,fire monitoring ,fire trend prediction ,fire source location ,multi-parameter fusio ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Based on analysis of principle and characteristics of mine fire monitoring methods such as temperature monitoring method, gas monitoring method, smoke monitoring method, visible light image monitoring method and infrared image monitoring method, a mine fire monitoring and trend prediction method based on multi-parameter fusion was proposed. Conclusions were got as following:① Thermocouple temperature measurement method and semiconductor temperature measurement method have advantages of high accuracy, strong real-time performance and early detection of early fire, but there are disadvantages such as large sensor consumption and large maintenance workload; Infrared temperature measurement method has advantages of wide monitoring range and easy sensor arrangement, but shielding and coal dust between sensor and measured object will affect monitoring result; Fiber distributed temperature measurement method has advantages of multi-point temperature monitoring and small amount of cable consumption, but there are disadvantages such as easy damage, complicated installation and difficult maintenance of optical fiber. ② Gas monitoring method and smoke monitoring method have advantages of wide monitoring range, convenient use and maintenance, but there are disadvantages such as cannot monitor early fire with low concentration of index gas and less smoke. ③ Visible light image monitoring method has advantages of wide monitoring range, convenient use and maintenance, low cost, but interference sources such as roadway light, miner's lamp, vehicle lamp and red clothes and smoke will affect monitoring effect, and the method cannot monitor early fire with no flame and less smoke.④ Infrared image monitoring method has advantages of wide monitoring range, convenient use and maintenance, but cost is high, and shielding and coal dust between infrared camera and measured object will affect monitoring effect. ⑤ Mine fire monitoring and trend prediction method based on multi-parameter fusion of temperature, smoke, gas concentration, odor, wind direction, wind speed, air volume, visible light image and infrared image can not only detect fire in time, but also locate fire source and predict fire development trend.
- Published
- 2019
- Full Text
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18. 矿井火灾监测与趋势预测方法研究.
- Author
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孙继平 and 孙雁宇
- Abstract
Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
19. The Effect of Different Fire Source Locations on the Environment of a Subway Station.
- Author
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Lei, Wenjun, Li, Angui, and Tai, Chuanmin
- Subjects
SUBWAY stations ,FIRES ,VISIBILITY ,TEMPERATURE ,CARBON monoxide - Abstract
The effect of different fire source locations on the environment of a subway station was investigated in this paper. Visibility, temperature and carbon monoxide at the evacuation stairs in the subway station were computed by Fire Dynamics Simulator (FDS). Different fire source locations have different evacuation features. Fire source 2and 3 have the most negative effect on evacuation. Therefore, relevant departments should take some measures to avoid fires breaking out in these places. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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20. A Probabilistic Inferential Algorithm to Determine Fire Source Location Based on Inversion of Multidimensional Fire Parameters.
- Author
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Chu, Y., Kodur, V., and Liang, D.
- Subjects
- *
FIRE detectors , *PARAMETER estimation , *BAYESIAN analysis , *INFERENTIAL statistics , *FIRE damage to buildings - Abstract
A probabilistic inferential framework is proposed to utilize transient temperature data measured at the ceiling of the compartment to determine location of fire source, as well as size of fire, based on Bayesian inferential theory. This approach treats the problem as one of parameter estimation, expressed as a function of posterior probability distribution based on the qualitative of agreement between predicted temperatures and observed temperatures at the sensor locations. A comparison of the measured temperature from full-scale burn tests with predicted temperatures from in verse problem solution algorithm indicate the error to be less than 5% when fires are small, but the error increases to more than 10% for large size fires. The accuracy of the inverse problem solution algorithm can be improved by utilizing data from sensitivity studies carried out on fire source location errors and heat release rate errors. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
21. Influence of fire source locations on the actuation of wet-type sprinklers in an office fire.
- Author
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Lai, Chi-ming, Su, Hung-Chi, Tsai, Ming-Ju, Chen, Chien-Jung, Tzeng, Chun-Ta, and Lin, Ta-Hui
- Subjects
SPRINKLERS ,FIRE protection engineering ,THERMAL conductivity ,OFFICE buildings ,GLASS transition temperature ,GAS flow - Abstract
Abstract: An experiment is conducted on a full-scale model office and an actual sprinkler system to explore the influence of fire source locations on sprinkler actuation. The office space is a brick structure that measures 5.7m in interior length, 4.7m in width and 2.4m in ceiling height, and equipped with a sprinkler system. The investigated fire source (100kW LPG burner) locations include the room center, wall centers, room corner, and other locations at different distances from sprinklers. The results show that actuation of the sprinklers is affected by the fire source locations and the heat conduction properties of the glass temperature-sensing bulb. Average actuation time of all the tests is 102s, around 40s faster than if the fire source is located in the room center. For fire sources in corners, sprinklers are quickly activated at the experimental time 75s, showing concentrated hot gas flow. [Copyright &y& Elsevier]
- Published
- 2010
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22. Temperature data-driven fire source estimation algorithm of the underground pipe gallery.
- Author
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Sun, Bin, Liu, Xiaojiang, Xu, Zhao-Dong, and Xu, Dajun
- Subjects
- *
BURIED pipes (Engineering) , *ALGORITHMS , *ANT algorithms , *ARTIFICIAL intelligence , *UNDERGROUND areas - Abstract
Since there exists few effective fire detection technologies for underground pipe gallery application, a temperature data-driven bio-inspired artificial intelligence algorithm is developed to detect fire source in 3D space of the underground pipe gallery, in which a simple physical model is used. In the developed algorithm, Ant colony optimization (ACO) is the first time to be used to determine tunnel fire source, and the new and special pheromone evaporation method and heuristic factor are developed for fitting the concerned problem here. Three fire experiments are used to support the ability of the algorithm. Satisfactory results can always be obtained, which shows that the developed algorithm can be used to estimate the tunnel fire source as well as temperature prediction. In addition, since only temperature data at several sensors is necessary in the developed algorithm, it has a very wide popularization and engineering application prospects due to its advantages of the global optimal ability and computational efficiency as well as the low economic cost. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
23. Influence of the competitive effect of V-shaped slope tunnel on smoke characteristics.
- Author
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Jiang, Xuepeng, Chen, Xinge, Xiao, Niqi, Liao, Xiangjuan, and Fan, Chuangang
- Subjects
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SMOKE , *HEAT release rates , *TUNNELS , *TRAFFIC congestion , *AIR flow - Abstract
• Simulate competitive effect of the V-shaped slope tunnel. • Study variation of the downstream back-layering length. • Propose partition of the smoke movement behavior. • Present relationship between mass flow rate and tunnel slope. Numerical simulations are conducted to study the influence of the heat release rate, the fire source location, and the tunnel slope on the smoke spread characteristics of V-shaped slope tunnels. Theoretical analysis and simulation results show that the smoke movement in the V-shaped slope tunnel is affected by the competition effect on both sides, which leads to the fact that the smoke only overflows from the tunnel portal closer to the fire source, and a large amount of air flows into the tunnel from the other portal. Due to the competition effect, the downstream smoke back-layering length first decreases and then increases slightly with the increasing distance between the fire source and the grade change point (refering to the intersection point of two adjacent slope lines). As the tunnel slope increases, both the back-layering length and the influence of the fire source location on the smoke spread decrease gradually. Besides, the heat release rate has little effect on the smoke movement characteristics. Based on the back-layering length and the mass flow rate distribution, the smoke movement behaviors in the V-shaped tunnel can be divided into the double-slope control zone, the transition zone, and the single-slope control zone. When the vertical distance between the fire source and the grade change point is more than 2.1 m, the smoke movement can be classified in the single-slope control zone. The mass flow rate reaches the peak value when the fire source is located in the transition zone, and the dimensionless mass flow rate is proportional to the tunnel slope and the 0.3 power of the dimensionless heat release rate. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
24. Study of smoke back-layering length with different longitudinal fire locations in inclined tunnels under natural ventilation.
- Author
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Kong, Jie, Xu, Zhisheng, You, Wenjiao, Wang, Beilei, Liang, Yin, and Chen, Tao
- Subjects
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SMOKE , *NATURAL ventilation , *TUNNELS , *BUILDING evacuation , *SYSTEMS design , *AIR flow , *VENTILATION - Abstract
• The fire smoke backflow in inclined tunnel is mainly driven by downstream length. • A non-dimensional empirical correlation of back-layering length and downstream length is established. • A new prediction formula of back-layering length account for tunnel slopes and downstream length is developed. To investigate the vehicle fire hazard at different locations in inclined tunnels, the effect of longitudinal fire locations on smoke behavior characteristics induced by inclined tunnel fires was proposed by simulation and theoretical analysis. A series of tunnel models with slope of 4% was conducted by Fire Dynamics Simulator (FDS) software for fire simulation, in which three fire scenarios were considered corresponding to the variation of fire location, upstream length and downstream length respectively. The results show that smoke back-layering length drops progressively with increasing of downstream length, and upstream inlet airflow velocity is linearly positively correlated with downstream length, while the upstream length has a limited impact on smoke movement. A new prediction equation of the dimensionless smoke back-layering length account for downstream length and tunnel slope was established, through the addition of height difference between fire source and downstream exit. The established correlation shows that the dimensionless smoke back-layering length is logarithmically related to cubic power of downstream length, and the predicted results agreed well with simulated data as tunnel slope from 3.5% to 7.5%. The results can provide beneficial suggestion in ventilation system design and emergency evacuation for inclined tunnels. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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