• Title/Summary/Keyword: Flammable

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Effect of Swirl Angles and Combustion Characteristics of Low Swirl Model Combustor (저선회 모델 연소기의 연소특성 및 선회각도 영향)

  • Jeong, Hwanghui;Lee, Keeman
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.4
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    • pp.40-49
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    • 2016
  • This study aims to confirm the characteristics of low swirl combustion at our low swirl model combustor. To do it, it is experimentally conducted by evaluating the flame shape, stability region and emissions according to the swirl angle. The most significant feature of low swirl combustion is a occurrence of lifted flame. Such lifted flames happen to combine exquisitely propagating feature of premixed flame with diverging flow. This feature of lifted flame was confirmed through a velocity flow field and visualized the flame in this model combustor. The visualized flame was classified according to the thermal power and equivalence ratio. The variation study in swirl angles showed that the lean flammable limit could be extended only by swirl angles. Also, as the swirl angle increased, it was confirmed that the NOx and CO emissions were decreased due to the mixing enhancement and shorter resident time.

A Study on Establishing Target Reliability Levels for Flammable Gas Transmission Pipelines (가연성가스 수송배관에 대한 목표 신뢰도 수준 설정에 관한 연구)

  • Lee, Jin-Han;Jo, Young-Do;Moon, Jong-Sam
    • Journal of the Korean Institute of Gas
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    • v.22 no.6
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    • pp.52-58
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    • 2018
  • In reliability based design and assessment (RBDA) methodology, reliability targets are used to ensure that safety levels are met relevant limit states in the stage of design and maintenance. The target reliability for flammable gas pipelines have not been developed yet in Korea. Instead of the reliability targets, the tolerable criteria for risk measures such as societal and individual risk have been applied in pipeline risk management. This paper introduces the procedures to develop the target reliability using tolerable risk criteria for societal and individual risk which can be enforced for high pressure natural gas pipelines in quantitative risk assessment. In addition, we propose the target reliability for natural gas and hydrogen gas transmission pipelines by the procedures.

A Study on the Safety of Carbon Manufacturing By-product Gas Emissions (카본제조 부생가스 배출 안전성에 관한 연구)

  • Joo, Jong-Yul;Jeong Phil-Hoon;Kim, Sang-Gil;Sung-Eun, Lee
    • Journal of the Korea Safety Management & Science
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    • v.26 no.1
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    • pp.99-106
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    • 2024
  • In the event of an emergency such as facility shutdown during process operation, the by-product gas must be urgently discharged to the vent stack to prevent leakage, fire, and explosion. At this time, the explosion drop value of the released by-product gas is calculated using ISO 10156 formula, which is 27.7 vol%. Therefore, it does not correspond to flammable gas because it is less than 13% of the explosion drop value, which is the standard for flammable gas defined by the Occupational Safety and Health Act, and since the explosion drop value is high, it can be seen that the risk of fire explosion is low even if it is discharged urgently with the vent stock. As a result of calculating the range of explosion hazard sites for hydrogen gas discharged to the Bent Stack according to KS C IEC 60079-10-1, 23 meters were calculated. Since hydrogen is lighter than air, electromechanical devices should not be installed within 23 meters of the upper portion of the Bent Stack, and if it is not possible, an explosion-proof electromechanical device suitable for type 1 of dangerous place should be installed. In addition, the height of the stack should be at least 5 meters so that the diffusion of by-product gas is facilitated in case of emergency discharge, and it should be installed so that there are no obstacles around it.

Experimental Study on Ignition and Explosion Hazard by Measuring the Amount of Non-volatile (NVR) and Explosion Limit of Biodiesel Mixture (바이오디젤 혼합물의 가열잔분측정과 폭발한계 측정을 통한 발화 및 폭발위험성에 대한 실험적인 연구)

  • Kim, Ju Suk;Koh, Jae-Sun
    • Journal of the Society of Disaster Information
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    • v.18 no.1
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    • pp.182-193
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    • 2022
  • Purpose: By measuring and evaluating the risk of biodiesel through non-volatile residue (NVR) and flash point and explosion limit measurement at a specific temperature according to ASTM test standards, the risk of chemical fire causative substances is identified and a universal evaluation method By derivation and securing the risk-related data of the material, it can be used for the identification and analysis of the cause of the fire, and it can be applied to the risk assessment of other chemical substances Method: In order to measure the risk of biodiesel, it was measured using the non-volatile residue(NVR) measurement method, which measures how much flammable liquid is generated at a specific temperature. Heating was tested by applying KS M 5000: 2009 Test Method 4111. In addition, the flash point was measured using the method specified in ASTM E659-782005, and the energy supply method was measured using the constant temperature method. In addition, the explosion limit measurement was conducted in accordance with ASTM E 681-04 「Standard test method for concentration limits of flammability of chemicals(Vapors and gases)」 test standard. Result: As a result of checking the amount of combustible liquid by the non-volatile residue (NVR)measurement method, the non-volatile residue(NVR) of general diesel when left at 105±2℃ for 3 hours was about 30% (70% of volatile matter) and about 4% of biodiesel. In addition, similar results were obtained for the non-volatile residue(NVR)heating temperature of 150±2℃, 3 hours and 200±2℃ for 1 hour, and white smoke was generated at 200℃ or higher. In addition, similar values were obtained as a result of experimentally checking the explosion (combustion) limits of general diesel, general diesel containing 20% biodiesel, and 100% biodiesel. Therefore, it was confirmed that the flammability risk did not significantly affect the explosion risk. Conclusion: The results of this study suggested the risk judgment criteria for mixtures through experimental research on flammable mixtures for the purpose of securing the effectiveness, reliability, and reproducibility of the details of the criteria for determining dangerous substances in the existing Dangerous Materials Safety Management Act. It will be possible to provide reference data for the judgment criteria for flammable liquids that are regulated in the field. In addition, if the know-how for each test method is accumulated through this study, it is expected that it will be used as basic data in the research on risk assessment of dangerous substances and as a basis for research on the determination of dangerous substances.

COMBUSTION CHARACTERISTICS OF WASTE-PYROLYSIS GASES IN AN INTERNAL COMBUSTION ENGINE

  • Shudo, T.;Nagano, T.;Kobayashi, M.
    • International Journal of Automotive Technology
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    • v.4 no.1
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    • pp.1-8
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    • 2003
  • Wastes such as shredder dust of disposed vehicles can be decomposed into low calorific flammable gases by Pyrolysis gasification. A stationary electric Power generation using an internal combustion engine fuelled with the waste-pyrolysis gas is an effective way to ease both waste management and energy saving issues. The waste-pyrolysis gas mainly consists of H$_2$, CO, $CO_2$ and $N_2$. The composition and heating value of the gas generated depend on the conversion process and the property of the initial waste. This research analyzed the characteristics of the combustion and the exhaust emissions in a premixed charge spark ignition engine fuelled with several kinds of model gases, which were selected to simulate the pyrolysis-gases of automobile shredder dusts. The influences of the heating value and composition of the fuel were analyzed parametrically. Furthermore, optical analyses of the combustion flame were made to study the influence of the fuel's inert gas on the flame propagation.

The Measurement and Estimation of Lower Flash Points for n-Propanol+Acetic acid and n-Propanol+n-Propionic Systems (n-Propanol+acetic acid 및 n-propanol+n-propionic acid 계의 하부 인하점 측정 및 예측)

  • Ha, Dong-Myeong;Lee, Sung-Jin
    • Journal of the Korean Society of Safety
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    • v.22 no.4
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    • pp.37-42
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    • 2007
  • Flash points for the flammable binary systems, n-propanol+acetic acid and n-propanol+n-propionic acid, were measured by Cleveland open cup tester. The Raoult's law, the van Laar equation and the UNIQUAC equation were used for predicting flash points and were compared with experimentally-derived data. The calculated values based on the van Laar and UNIQUAC equations were found to be better than those based on the Raoult's law. And the predictive curve of the flash point prediction model based on the UNIQUAC equation described the experimentally-derived data more effectively than was the case when the prediction model was based upon the the van Laar equation.

A Study on the Assessment of Hazardous Properties of the Chemicals (화학물질의 위험성평가에 관한 연구)

  • Lee, Bong-Woo;Park, Chul-Woo;Song, Haak;Choi, Jeong-Soo
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.262-269
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    • 2008
  • Chemical products have had an favorable influence on our everyday life, and contributed very much to the development of human culture. According to the rapid change of industry and the development of scientific technique the using chemical products are increasing more and more. Chemical products can have any hazardous property such as flammability or explosiveness. There are occurring many accidents in the international trade due to the different classification and labelling of chemicals produced in various countries. The main purpose of this work is the development of global standard test methods for the chemicals, and the classification and labelling in building block approach by means of the basic technical data. Oxidizing solids, combustible solids, spontaneously combustible materials, water-prohibitive materials, flammable liquids, self-reactive materials and oxidizing liquids have been tested. The results have been classified according to the hazard material safety regulation and the UN regulation, and summarized in a data-base.

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Influence of changing Combustor Pressure on Flame Stabilization and Emission Charncteristics (연소실 압력변동이 화염안정화와 배출특성에 미치는 영향)

  • Kim, Jong-Ryul;Choi, Gyung-Min;Kim, Duck-Jool
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2354-2359
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    • 2007
  • Influence of changing combustor pressure on flame stabilization and emission index in the swirl-stabilized flame was investigated. The combustor pressure was controlled by suction fan at combustor exit. Pressure index ($P^{\ast}$=Pabs/Patm), where Pabs and Patm indicated the absolute pressure and atmosphere pressure, respectively, was controlled in the range of 0.7${\sim}$1.3 for each equivalence ratio conditions. The flammable limits of swirl flames were largely influenced by changing combustor pressure and they showed similar tendency with laminar flames. NOx emission index decreased with decreasing pressure index for overall equivalence ratio conditions. R.m.s. of pressure fluctuations is increased with decreasing combustor pressure. This flame fluctuation caused incomplete combustion, hence CO emission index increased. These oscillating flames were measured by simultaneous $CH^{\ast}$ chemiluminescence time-series visualization and pressure fluctuation measurement.

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Fire Identification based on Physical Properties of Bean Oil (대두유의 물리적 특성에 따른 화재감식)

  • Jin, Bog-Kwon;Jung, Soo-Il
    • Fire Science and Engineering
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    • v.22 no.3
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    • pp.246-251
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    • 2008
  • Oil Fire easily generates fire in the pressure of the atmosphere and below the normal temperature. Because these discharge flammable gas and ignite within the combustibles limit in conditioning to be assisted air and an invariable density. But Kitchen Fire shows very specific properties of matter and energy Qualification in most cases even though the same oil fires occured. In this Paper, around these specific character that Kitchen Fire have Properties of matter or energy Qualification studied on the genetic mechanism and counter measure scheme.

THE NUMERICAL SIMULATION OF HYDROGEN DIFFUSION FOR THE HYDROGEN LEAKAGE IN TUNNEL (터널 내 수소연료 자동차의 수소 누설로 인한 수소 확산에 대한 수치해석 연구)

  • Ahn, Hyuk-Jin;Jung, Jae-Hyuk;Hur, Nahm-Keon;Lee, Moon-Kyu;Yong, Gee-Joong
    • Journal of computational fluids engineering
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    • v.15 no.2
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    • pp.47-54
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    • 2010
  • In the present study, a numerical simulation for the diffusion of hydrogen leakage of FCV(Fuel Cell Vehicle) in a tunnel was performed to aid the assessment of risk in case of leakage accident. The temporal and spatial distributions of the hydrogen concentration around FCV are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate the effectiveness of tunnel ventilation system for relieving the accumulation of the leaked hydrogen gas. The distribution of the concentration of the leaked hydrogen for various cases can be used as a database in various applications for the hydrogen safety.