• Title/Summary/Keyword: Ignition possibility

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A Study on the Spontaneous Ignition Possibility of Shredded Waste Thermoplastic Elastomer (폐 열가소성 플라스틱 탄성체 분쇄물의 자연발화가능성에 관한 연구)

  • Park, Young Ju;Lee, Hae Pyeong;Goh, Kyoung Chun;Eom, Young Sup
    • Journal of the Korean Society of Safety
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    • v.31 no.1
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    • pp.61-65
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    • 2016
  • In this study, we considered the ignition possibility for the shredded thermoplastic elastomer at the fire ground loaded the waste TPE. The average moisture content of the TPE sample was almost 0.33 wt.% at $110^{\circ}C$ and the range of ignition point was $461.9{\sim}491.9^{\circ}C$ approximately. In addition, we analyzed the change of weight and calorie the TPE sample according to temperature variations using the TG-DTA analyzer. As a result, the weight loss occurred twice in $250{\sim}420^{\circ}C$ and $420{\sim}473^{\circ}C$, and we found the second weight loss temperature range was the ignition point of TPE. Also, we conducted the spontaneous ignition tests of TPE for the wet and dry samples and we confirmed that the possibility of spontaneous ignition of TPE was very low. The elapsed time and humidity had little influence on the spontaneous ignition of TPE in this experimental conditions. In conclusion, the spontaneous of the shredded waste TPE in this study.

An Experimental Study on Correlation of Compression Ignition Condition at Cold Start with Hydrogen HCCI Engine (냉시동시 압축착화 조건의 상관관계에 관한 수소 HCCI 기관의 실험적 연구)

  • Lee, Kwangju;Lee, Jonggoo;Ahn, Byunghoh;Lee, Jongtai
    • Transactions of the Korean hydrogen and new energy society
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    • v.23 no.6
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    • pp.628-633
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    • 2012
  • It was found that the pure hydrogen-air pre-mixture was self-ignited at a high compression ratio without any assisting method in room temperature, thus refuting the preconception that compression ignition of hydrogen engine was impossible. Therefore, in order to analyze the correlation of compression ignition condition at cold start with hydrogen HCCI engine clearly, the possibility of compression igniting compression ratio is investigated with the change of equivalence ratio and engine speed, experimentally. As the results, it is confirmed that the possibility of compression-igniting compression ratio at cold start was decreased by increasing equivalence ratio due to decreasing auto-ignition temperature. In addition, it is grasped that the possibility of compression-igniting compression ratio at cold start is decreased around 14.9% by increasing engine speed at same supply energy.

Fire Risk Analysis through Airfryer's Fire Cases and Reproduction Experiments (에어프라이어의 화재사례와 재현실험을 통한 화재위험성 분석)

  • Lee, Jung-Il;Jo, Myeng-Sik
    • Journal of the Korea Safety Management & Science
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    • v.22 no.2
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    • pp.39-46
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    • 2020
  • This paper recognizes the risk of ignition of air fryer (machine that can cook fried dishes with hot air without oil) that is far exceeding the sales rate of microwave ovens, which is necessary to modern household kitchen, and identifies fire risk through the operation principle of the process of heat transfer, and the main structure of the machine. The fire test that we conducted is to observe the risk of ignition of the machine due to the damage to the safety system and the possibility of igniting oil paper along with food, to experiment with the possibility of ignition due to blockage of the exhaust due to obstacles, and accumulation of oil stains on the hot wire, and to present the method of fire control and devise countermeasures.

Analysis of Electrical and Thermal Signal for Series Arc in Electrical Contact (전선의 접속부에서 직렬아크에 의한 전기적 및 열적 신호 분석)

  • Kim, Doo Hyun;Hwang, Dong Kyu
    • Journal of the Korean Society of Safety
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    • v.30 no.5
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    • pp.1-7
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    • 2015
  • This paper is aimed to analyze the electrical and thermal signal such as ignition possibility, ignition time, thermal characteristics and arc fault power that are associated with electrical fire in case of the occurrence of series arc at IV wiring used for interior wiring at commercial power source. In order to analyze the signal, series arc was induced by generating the constant vibration through vibrating device in the one phase (R phase) and ignition possibility was analyzed along the condition of current value by adding cotton material to the contact point of wiring. The ignition time is shortened as the electric current value increased, burning time is not associated with current value and the temperature rose up to $740^{\circ}C$ though it was not ignited. It was checked out that the temperature was the energy source enough that can generate the fire related with insulation aging of wiring and the inflammable. The possibility of electrical fire by series arc was shown as more than 12% at 5A, more than 42% at 20A and arc showed 27W at 5A, 180W at 20A. It was confirmed that the possibility of electrical fire exists at the condition as above and the circuit breaker did not operate. This data can be used as the reference value for the investigation of electrical fire or development of the circuit breaker.

Construction of Diagnosis System for Electric-fire Causes using Fuzzy Possibility Measure (퍼지가능성 척도를 이용한 전기화재 원인진단 시스템의 구축)

  • 김두현;김상철
    • Journal of the Korean Society of Safety
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    • v.7 no.4
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    • pp.105-114
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    • 1992
  • This paper presents an study on the knowledge based system for diagnosing the fire causes using the Fuzzy Possibility Measure( FPM ) about the electric-fire ignition. The Ignition values needed for causes diagnosis is computed as FPM for electric-fire ignition based on the internal scale technique that assigns numerically the characteristic difference of facts to the-tin-ear scale. For the convinience of inference, ignition sources are classified into seven types : short, ground fault, leakge of electricity, overcurrent, cord junction overheating, bad Insulation and spark. The system for causes diagnosis of electric-fire is composed of Knowledge Acquisition System, Inference Engine and Man-Machine Interface, The diagnosis system is wrritten in an artificial intelligence langusge “PROLOG” which uses depth-first search and backward chaining schemes in reasoning process.

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A Study on the Ignition Hazards of Flammable Mixtures by Radio Frequency Radiation (고주파 방사에 의한 가연성가스의 점화 위험성 고찰)

  • Choi, Sang-Won;Lee, Gwan-Hyung;Moon, Jung-Gi
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1749-1751
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    • 1998
  • Close to high power radio/radar transmitters there is a possibility that sparks may be occur at discontinuities in metallic structures. If these structures are in an area in which a flammable mixture may be present, there is a possibility that a fire or explosion may be caused by the sparking. A number of assessment procedures for quantification of the hazard have been produced. This paper reviews the bases of the British Standard covering ignition hazards by radio-frequency radiation and presents some ignition test apparatus to access these hazards.

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Methodology to evaluate Fuel Quality in terms of Ignition and Combustion (연소 관점에서 본 연료 품질 판단 방법)

  • Kim, Jeong Do;Cho, Kwon Hae;Choi, Jae Sung
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2012.06a
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    • pp.113-116
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    • 2012
  • The ignition quality in diesel engines is one of the most important factors influencing their performance. While the ignition quality of distillation fuels is judged with Cetane Number, Cetane Index, and Diesel Index, that of residual fuels blended with distillation fuels is done by using CCAI. Since the 1980s, because of the development in the blending technology and the complexity, it has been difficult to make a judgement on the ignition quality of the fuels with CCAI. Hence, in order to solve the problems, it is ECN that researchers are studying in depth. In this paper, After reviewing the values such as Cetane Number, Cetane Index, Diesel Index, CCAI, and CII, we will introduce ECn and predict the possibility of using it.

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Effects of a wall on the self-ignition of sudden release of high-pressure hydrogen through a tube (벽면에 의한 고압 수소 누출에 따른 자발화 현상 특성 변화)

  • Kim, Seihwan;Park, Ji Hyun;Lee, SeungBok;Lee, Hyung Jin;Jeung, In-Seuck
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.245-246
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    • 2012
  • The possibility that self-ignition can be generated near an obstacle is high in practical applications such as a hydrogen car. In this paper, experimental investigations were suggested to understand the effects of a wall on self-ignition phenomena through high-speed images. The results showed that the existence of a wall could not change the ignition phenomena itself irrespective of wall height and burst pressure. However, when a strong flame was induced in the tube, a wall could promote the flame stabilization.

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Effects of Pilot Injection Method Following the Main Injection on Ignition Promotion and Exhaust Gas Reduction in a Diesel-Fueled HCCI Engine (디젤 예혼합압축착화엔진에서 주연료 분사 후 점화 연료 분사 방법을 통한 점화 촉진과 배기가스 개선 효과)

  • Kook, Sang-Hoon;Bae, Choong-Sik
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.27-32
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    • 2003
  • Diesel-Fueled HCCI(Homogeneous Charge Compression Ignition) Engine is an advanced combustion process explained as a premixed charge of diesel fuel and air is admitted into the cylinder and compression ignited. It has possibility to reduce NOx by spontaneous auto-ignition at multiple points that allows very lean combustion resulting in low combustion temperatures. Also PM could be reduced by the premixed combustion and no fuel-rich zones. But HCCI couldn't be realized because of the difficulties in vaporizing the diesel, control of combustion phase directly. To solve these problems, new fuel injection strategy, explained as the pilot fuel injection to promote ignition near TDC following the main fuel injection at the extremely advanced timing, is applied during the compression ratio is varied from 18.9:1 to 27.7:1 This is not a pilot fuel to promote the ignition but also the direct control method of the combustion phase. Experimental result shows the pilot fuel injection promote the ignition and the compression ignition of the HCCI engine is achieved as compression ratio becomes higher. Also there is an optimal pilot fuel injection timing for the HCCI combustion. NOx is reduced more than 90% compared to DI-Diesel case but PM and THC emission needs more investigation.

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Design consideration for protecting fuel tank explosion (항공기 연료탱크 폭발 방지를 위한 설계 방안 연구)

  • Kim, Seung-kyem
    • Journal of Aerospace System Engineering
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    • v.6 no.1
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    • pp.7-12
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    • 2012
  • Fuel tank design requires special care because tank explosion can cause catastrophic event with high possibility as shown in accident of TWA 800. In this study, cause of fuel tank explosion was reviewed and several design considerations to minimize explosion possibility were introduced.