International Journal of Fire Science and Engineering最新文献

{"title":"Fire Dynamics Simulator Analysis of Smoke Confinement and Radiation Shielding using Water Mist Curtains","authors":"G. Ko","doi":"10.7731/kifse.c5a02c0f","DOIUrl":"https://doi.org/10.7731/kifse.c5a02c0f","url":null,"abstract":"This research was conducted to numerically analyze the smoke confinement and radiation shielding characteristics of water mist curtains during the process of plume flow that propagates along the ceiling after its occurrence in fire source. We reviewed the flow field based on the location of the spray, size of water mist droplets, temperature distribution, and soot distribution. The optical density extracted at a height of 1.5 m and the thermal radiation attenuation rate values were comparatively analyzed. In the case of no water-mist operation, the temperature and soot concentration were stable as they formed a layer toward the floor from the ceiling. By contrast, when the water mist curtain was operational, the spray flow obstructed the ceiling jet flow and caused considerable mixing. The results from reviewing the optical density predictions showed that it tended to decrease at a distance sufficiently far downstream of the curtain, but overall the effect was not meaningful compared to the case of no water-mist operation. This was considered to be because a considerable number of fine droplets, as well as soot particles included in the smoke, affected the optical density. Conversely, the attenuation rate of thermal radiation was greatly affected by the average size of the droplets. In the case when the location of the water mist curtain was xinj = 6 m, the thermal radiation attenuation rate at the lowermost part changed from 79.0%, 29.7%, and 17.0% as the average spray droplet size increased from 200, 500, and 1,000 μm., respectively.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114478770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Evacuation Time for Each Evacuation Equipment in Neighborhood Facilities: Focused on Descending Lifeline and Elevating Equipment for Evacuation","authors":"Lauren Bae, Ryun-Seok Oh, Jun-Ho Choi","doi":"10.7731/kifse.e6d7eca7","DOIUrl":"https://doi.org/10.7731/kifse.e6d7eca7","url":null,"abstract":"At present, the standard for installing evacuation equipment that enables occupants to evacuate on their own is determined by the use of a building and its floor area. However, according to the \"Installation Maintenance and Safety Control of Fire-Fighting Systems Act\" and \"Fire Safety Standards for evacuation equipment\", the installation standard for evacuation equipment mentions only the minimum number of equipment to be installed based on the floor area. Thus, this installation standard fails to reflect the corresponding number of occupants in a building and the effectiveness of the evacuation equipment. Thus, there is a high probability that most of the evacuation equipment installed based on the \"one-size-fits-all\" legal regulation will not guarantee the safety of occupants in case of a fire. To address this, the performance evaluation of the effectiveness of evacuation and the distribution ratio of equipment per occupant needs to be prioritized. Therefore, we conduct mock experiments on the descending lifeline and elevating evacuation equipment to analyze their efficiencies. Moreover, we propose a model for calculating the evacuation time for the descending lifeline and elevating evacuation equipment based on the experimental results. Furthermore, we conduct effectiveness evaluation by using the evacuation equipment. The results show that most people cannot be evacuated using the evacuation equipment. That is, evacuation equipment was determined to be insufficient for ensuring safety as per the current standard. Therefore, the installation of evacuation equipment according to its efficiency and capacity is considered necessary.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116772491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study on the Fire Property of Pure Polymers and Polymer Mixture Pellets","authors":"Jung Yong Kim, Su-Gyeong Min, S. C. Kim","doi":"10.7731/kifse.f9840ba0","DOIUrl":"https://doi.org/10.7731/kifse.f9840ba0","url":null,"abstract":"The present study conducted a series of fire tests using a cone calorimeter to understand the effects of pure polymers and polymer mixtures on fire properties. An initial fuel mass of 50 g in a 10-cm-diameter pan was placed on the load cell. Polystyrene, polyethylene, polymethylmethacrylate, polystyrene-polyethylene mixture, and polystyrene-polymethylmethacrylate mixture was used as fuel. The fuel ignited using a pilot burner was allowed to burn freely. The fire properties of polymer mixtures, such as the mass loss rate, the effective heat of combustion, the CO yield rate, and the soot yield rate, did not depend on the mixture composition or fuel types, suggesting it is difficult to apply the statistically representative values of fire properties of the mixture. Therefore, quantitative measurements based on experiments and their database are necessary for reasonable fire analysis.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134052373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Vent Area Ratio on Vent Flow Characteristics and Temperature D istribution in a C ompartment F ire with T wo Ceiling Vents","authors":"Y. Park, C. Lee","doi":"10.7731/kifse.72cdba0d","DOIUrl":"https://doi.org/10.7731/kifse.72cdba0d","url":null,"abstract":"In this study, the effect of the vent area ratio on vent flow characteristics and temperature distribution in a compartment during a fire in the compartment with two ceiling vents was examined. The area ratio (A1/A2) between ceiling vent 1 (CV1), with a duct height of 0.19 m, and ceiling vent 2 (CV2), with a duct height of 0.05 m, was varied from 0.052 to 0.542, 1, 5.587, and 19.36, and numerical simulation was performed under these conditions. As the A1/A2 ratio increased, the flow pattern changed from unidirectional inflow to bidirectional flow for CV1 and from bidirectional flow to unidirectional inflow for CV2. When the A1/A2 ratio was 0.542, the outflow and inflow mass flow rates for CV1 and CV2 were found to be nearly equal. The outflow and inflow mass flow rates at CV1 were higher than those at CV2 when the A1/A2 ratio was high, while the outflow and inflow mass flow rates at CV2 were higher than those at CV1 when the A1/A2 ratio was low. Furthermore, it was observed that the temperature was lower and the temperature difference between the higher and lower regions in the upper part of the measurement position decreased near the lower part of the vent with a larger area compared to the vent with a smaller area. This was probably because the mixing effect increased near the vent with a larger area due to the occurrence of the active bidirectional flow pattern. When the flow pattern at CV1 was bidirectional, the previous correlation for predicting mass flow rate was examined. It was found that the previous correlation underestimated the mass flow rate of the numerical simulation conducted in this study.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133093351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Examining Microdroplet Characteristics of Electrospray Electric Precipitation for Direct and Indirect Voltage Application Methods","authors":"Jiwon Choi, Keesin Jeong, Haiyoung Jung","doi":"10.7731/kifse.75841f94","DOIUrl":"https://doi.org/10.7731/kifse.75841f94","url":null,"abstract":"Dust and fine dust exist in various forms and can lead to various problems such as dust explosion and air pollution. To reduce them, recently, research on electrospray electric precipitation, among various dust collection methods, has been actively conducted. In this study, comparative analysis experiments were performed on microdroplet generation characteristics for direct and indirect charging methods of electrospray electric precipitation. A visualization device was fabricated to generate microdroplets, and microdroplets were photographed with a high-magnification camera according to each charging method. The size and number of microdroplets were then analyzed via ImageJ software.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122713024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Duct Height and Fire Location on Fire Phenomena of Enclosure with Two Horizontal Vents Installed on Ceiling","authors":"Y. Park, C. Lee","doi":"10.7731/kifse.1b44ea08","DOIUrl":"https://doi.org/10.7731/kifse.1b44ea08","url":null,"abstract":"The effects of duct height (DH) and fire location (FL) in an enclosure on the mass flow rate and flow pattern of horizontal vent (HV) flow and temperature distribution in the enclosure were investigated through numerical simulations under the condition that two HVs were installed on the ceiling of the enclosure. To evaluate the effect of DH, DHs of HV1 were set to 0.19 m (HV1_DH0.19) and 0.05 m (HV1_DH0.05) under the condition that DH of HV2 was 0.05 m (HV2_DH0.05). The effect of FL was evaluated in three cases where the fire sources were located in the center of the floor (F LC), below HV1 (F L1), and below HV2 (F L2). With respect to the DH effect, the total mass flow rate of the vent flow was slightly higher and temperature was slightly lower in the case of HV1_DH0.19 than that in the case of HV1_DH0.05. However, considering the error bars, the effect of DH in this numerical simulation condition was considered to be insignificant. Furthermore, bidirectional flow patterns appeared in HV1 and HV2 in both DH conditions. Meanwhile, with respect to the FL effect, a bidirectional flow dominated by the mass flow rate of outflow occurred in the HV where the fire source was located, and a unidirectional inflow dominated by the mass flow rate of inflow occurred in the HV where the fire source was not located. The total mass flow rates of FL1 and FL2 conditions were similar, which were higher than those of FLC condition. The temperature was higher in FLC than those in FL1 and FL2. This was due to the small mass flow rate through the HV in the FLC. Meanwhile, an increasing trend of the temperature with the rising measurement height from the floor was observed at most of the temperature measurement points. However, when the fire source was located below HV1 and HV2, as the height from the floor increased, the temperature decreased and the overall temperature was low at the temperature measurement points below the vent where the fire source was not located. This trend was attributed to the occurrence of a strong unidirectional inflow wherein a large volume of low-temperature air flowed into the enclosure from the HV where the fire source was not located.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121977613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of FDS to Predicting Fire Spread in a Horizontal Cable Tray","authors":"Hyo-Yeon Jang, Ho-Sik Han, Cheol-Hong Hwang, Sang Kyu Lee","doi":"10.7731/kifse.030659d0","DOIUrl":"https://doi.org/10.7731/kifse.030659d0","url":null,"abstract":"With regard to cable tray fires, comparing the prediction results obtained through fire simulations with the measurement results from fire experiments conducted under real-life conditions is essential to ensure the predictive reliability of the model. In determining the validity of the calculation process and procedure performed in a specific fire experiment, the result may vary depending on the user’s capability. This is because of the high user dependence due to the characteristics of the fire model. In this study, we examined whether the actual spread of fire could be similarly predicted when the physical quantities of cable tray fires suggested by previous studies were applied. We also applied a fire modeling method considering the arrangement of cables to predict appropriate fire spread in a nuclear power plant and then performed a comparative analysis of the results and the experimental results. The prediction results, in terms of the fire spread time, varied depending on the arrangement type (whether loosely and tightly arranged) of cables. Finally, we devised a process of accurately predicting the heat release rate (HRR) curve as compared to the experimental results by using a sensitivity analysis of the input parameters (density, specific heat, and thermal conductivity) corresponding to the physical properties considered in the fire model.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131463633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Location Recognition of Indoor Firefighting Facilities based on RGB-D Camera and 3D LiDAR","authors":"J. Jeon, Dagun Oh, S. Hong, K. Lee","doi":"10.7731/kifse.b3b0bd61","DOIUrl":"https://doi.org/10.7731/kifse.b3b0bd61","url":null,"abstract":"Recently, as fires frequently occur in large buildings, digital twin (DT) technology that enables remote and real-time monitoring and control similar to the real world environment is being studied as a disaster response technology in buildings. In order to use DT technology, it is essential to collect the spatial data of actual building indoor environments and firefighting facilities. This study proposes an indoor spatial data collecting system that can generate the modeling data inside the building and location data of firefighting facilities using laser imaging detection and ranging (LiDAR) and RGB-D cameras. First, point clouds from three-dimensional (3D) LiDAR and the FAST-LIO2 (Fast LiDAR-Inertial Odometry) algorithm are used to obtain odometry information in an indoor environment. The firefighting facilities located inside the building are detected using RGB images and the deep learning model Faster region-based convolutional neural network (R-CNN) with Inception V2 architecture trained using RGB images of four types of firefighting facilities: fire extinguishers, fire hydrants, exit signs, and fire detectors. When a firefighting facility is detected, the relative distance between the RGB-D camera and the firefighting facility is calculated through the depth image and intrinsic parameters of the RGB-D camera. Afterwards, odometry information obtained from FAST-LIO2 and the relative distance are combined to obtain the 3D location of the firefighting facility. Point clouds of the FAST-LIO2 algorithm are then converted into models of the building indoor environment. Through this method, spatial data of an actual building can be constructed and used with DT technology.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132781398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Optical Properties of Smoke Particles on Fire Detection Characteristics predicted by a Fire Dynamic Simulator Model","authors":"Ter-Ki Hong, S. Park","doi":"10.7731/kifse.96827602","DOIUrl":"https://doi.org/10.7731/kifse.96827602","url":null,"abstract":"This study examined the smoke detection time prediction performance of the Fire Dynamics Simulator (FDS) in relation to the optical properties of smoke particles. Specifically, this work explored how smoke detection times are affected by the mass-specific light extinction coefficient, an input value needed to predict FDS smoke detection times. Therefore, a smoke generator and a smoke detection sensor that employs the light extinction principle were installed in a fire compartment, with the mass-specific light extinction coefficients of the smoke particles generated by the smoke generator measured through Gravimetric Sampling and Light Extinction (GSLE) experiments. FDS fire simulations were performed under the same conditions as the smoke detection experiments to compare the Optical Per Meter (OPM) of the detector. The results confirmed that the F DS fire simulation was consistent with the smoke detection experiments when the measured mass-specific light extinction coefficient of the smoke particles was entered as input. In addition, it was found that fluctuations in the mass-specific light extinction coefficient, an optical property of smoke particles, may significantly affect smoke detection times by directly affecting the OPM.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127423975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Necessity of Protective Coordination Systems According to Battery Capacity","authors":"Sin-Dong Kang, Ahran Min, Ye-Jin Park, S. Kim, Jae-Ho Kim","doi":"10.7731/kifse.59f10ab7","DOIUrl":"https://doi.org/10.7731/kifse.59f10ab7","url":null,"abstract":"As the capacity of lithium-based batteries rapidly is increasing, the number of applications using them is continuously increasing. However, this leads to the risk of fire and explosion, and thus, the number of accidents is increasing. To analyze the magnitude of short circuit currents according to the battery capacity and external circuit impedance and the necessity of protective coordination, this study conducted experiments using cylindrical batteries with capacities of 800, 2200, 3000, and 5000 mAh and cables with an impedance of 0.1Ω/m. Results indicated that as the battery capacity increased, the short circuit current increased and circuit-opening time decreased. However, as the circuit impedance increased, the short circuit current decreased and circuit-opening time increased. Based on these results, we reviewed protective systems applied to batteries and analyzed their problems. For protective systems designed considering the maximum short circuit current, if the state of charge is low or the impedance is high at the point of short circuit, the protective system does not operate when short circuit occurs, thus failing to block the circuit and potentially leading to fire. Therefore, while designing protective systems, it is appropriate to use multiple circuit breakers and fuses, considering the short circuit current according to the battery capacity and circuit impedance to enable protective coordination between devices.","PeriodicalId":225639,"journal":{"name":"International Journal of Fire Science and Engineering","volume":"238 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116105145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}