• Journal of Advanced Marine Engineering and Technology
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• 제18권2호
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• pp.91-96
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• 1994

Intake gases other than air, which is composed of oxygen, nitrogen, carbon dioxide, and argon, are used to study their effects on the performance of the diesel engine experimentally. The engine is operated at constant speed and fixed fuel injection timing, and cylinder pressure and heat release rate are measured at various intake gas compositions. The results show that increase of oxygen concentration improves the performance of the engine generally. The adverse effect is observed when the oxygen concentration is increased over the critical oxygen concentration of this test, mainly because of the over-shortened ignition delay. Increase of carbon dioxide concentration degardes the performance of the engine, mainly due to the lower specific heat ratio of carbon dioxide. Adding argon gas to the intake gas improves the overall performance. Finally, it is found that two most influencing factors affecting the performance of the diesel engine in this study are ignition delay and speific heat ratio of the intake gas.

• 대한기계학회논문집
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• 제19권10호
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• pp.2607-2616
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• 1995

The influences of number of spark plug on ignitability, combustion characteristics and combustion promotion effect were examined to establish the design conception of spark ignition system for lean burn. Ignitability was increased remarkably by increasing of number of spark plug at combustion wall. Combustion duration was shortened and maximum combustion pressure was increased in accordance with increasing of spark plug number. Rate of overall combustion promotion considered of combustion duration and combustion pressure was 28% in two point ignition and 40% in four point ignition. It was verified that heat release, heat loss and combustion duration were affected by flame area, heat transfer area and maximum flame travel distance respectively.

• 한국자동차공학회논문집
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• 제2권3호
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• pp.85-93
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• 1994

The engine performance and combustion characteristics of diesel oil and fish oil blended with diesel oils were investigated at various blending rate of fish oil in a diesel engine. The maximum pressure showed no significant difference among test fuels at low load, but it was higher as the blending rate of fish oil increases at high load. Increasing the blending rate of fish oil, the rate of heat release and burned fraction were higher than those of diesel oil. The ignition delay became longer than that of diesel oil as the blending rate of fish oil increases, and its differences were larger at different loads. The combustion duration and density of smoke were shorter and lower as the blending rate of fish oil increases. The rate of fuel consumption showed no significant difference between diesel oil and fish blended with diesel oils.

• 한국화재소방학회논문지
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• 제25권3호
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• pp.57-62
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• 2011

본 논문에서는 한옥 부재로 사용되는 육송을 대상으로 도포법과 상압함침법의 방염처리 방법을 적용하여 각 연소특성을 평가하였다. 도포 처리는 시험체 표변에 2-3회 붓칠한 후 24h 건조하는 것을 3회 반복하였고, 상압함침 처리는 시험체를 약제 속에 72h 동안 함침시켜 처리하였다. 연소특성 평가방법으로는 멕켈버어너를 사용한 방염성능 시험, 콘칼로리미터를 사용한 열방출률 시험방법을 적용하였다. 시험 결과 방염성능에 있어서 두 가지 방법으로 처리한 시험체는 모두 현재 합판에 대한 성능기준을 만족하였으며, 상압함침 처리보다는 도포 처리한 시험체의 방염성능이 더 우수하게 나타났다. 열방출률 시험 결과로는 착화까지의 시간, 최대열방출률, 질량감소율 총방출열량 등의 지수에서 상압함침 처리보다는 도포 처리한 시험체가 더 높은 성능을 보였다.

• 대한기계학회논문집B
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• 제34권5호
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• pp.449-456
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• 2010

HCCI 엔진은 고효율, 저공해를 실현할 수 있는 차세대 내연기관이다. 그러나 HCCI 엔진이 상용화되기 위해서는 몇 가지 문제점들이 해결되어야 한다. 그 중에서 가장 큰 문제점은 과도한 압력 상승률이 노킹을 발생시키기 때문에 운전영역이 제한되는 것이다. 이번 연구의 목적은 HCCI 엔진에서 압력상승률 저감을 위하여 온도 성층화와 농도 성층화 효과를 조사하는 것이다. 그리고 Multi-zone 모델을 이용한 화학반응 수치해석을 통하여 연소 및 배기가스 특성에 미치는 영향을 알아보았다. 수치해석에서 2 단계 열발생을 가지는 DME와 1단계 열발생을 가지는 메탄을 사용하였다.

• 한국안전학회지
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• 제29권3호
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• pp.114-120
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• 2014

The purpose of this study is to conduct the study of the combustion and thermal characteristics through transportation oil for the analysis of fire hazard. Transportation oil breaks down into fuels such as diesel for civilian demands, gasoline, DF1(diesel for military), high sulfur diesel(for marine), kerosene and JP1(for aviation), and lubricants like brake fluid, power steering oil, engine oil, and automatic and manual transmission oil. The experiments of flash point, ignition point, flame duration time, heat release rate were carried out using TAG closed cup flash point tester(AFP761), Cleveland open cup auto flash point analyzer(AFP762), KRS-RG-9000 and Dual cone calorimeter. As a result, the fuel's ignition points were lower than lubricants, especially that of gasoline was not conducted as it has below zero one. Gasoline has the highest ignition point of about $600^{\circ}C$, while the other fuels showed $400{\sim}465^{\circ}C$. For flame duration time, lubricants had over 300 seconds, but fuels had less than 300 seconds except high sulfur diesel(350 seconds). Total heat release rate ranged $287{\sim}462kW/m^2$ for lubricants and gasoline showed the highest total heat release rate, $652kW/m^2$.

• Journal of the Korean Wood Science and Technology
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• 제51권5호
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• pp.410-418
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• 2023

In this study, the combustion characteristics of the Tulip tree, which is the representative broad-leaved afforestation tree in Korea, were analyzed. The flame retardant performance of the Tulip tree was analyzed by analyzing combustion characteristics on a total of three test samples; flame retardant treated, both flame retardant and oil stain-treated, and untreated. Then the flame retardance grade was classified for each of them. According to the result, test samples showed the strongest flame retardance were in order of flame retardant treated (C), both flame retardant and oil stain-treated (B), and untreated (A). As a result of analyzing the total heat emission and maximum heat emission rates, which is the evaluation standard for interior materials of Korean domestic buildings, test samples with flame retardant treat or flame retardant and oil stain treat were qualified for the flame-retardant standard. Both flame retardant and oil stain-treated samples showed higher total heat release (THR) and heat release rate compared to flame retardant-treated samples as the oil causes combustion with oxygen. On the other hand, they didn't qualify the THR in Quasi-non-combustible standards. To determine the correlation between the physical and combustion characteristics of wood, the combustion characteristics of other diffuse porous wood species, with which the Tulip tree is affiliated were analyzed, and noticed that the characteristic correlates with the density and quantity of wood. The results of this study are expected to be used as basic information on the combustion characteristics of the Tulip tree.

• 한국화재소방학회논문지
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• 제32권5호
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• pp.34-39
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• 2018

본 연구에서는 구획 공간 화재 시 발열량이 급격히 변하는 조건에서 스프링클러헤드의 손실인자 변화에 따른 작동시간을 분석하였다. 이를 위해서 내화보드로 구성된 구획 공간의 크기가 폭 0.3 m, 세로 0.5 m, 길이 3.0 m인 구조물을 제작하고 헵탄(n-Heptane) 풀 화재 실험을 수행하여 구획 공간 내부의 온도 분포, 헵탄의 질량감소율 그리고 발열량을 산출하였다. 또한, Fire Dynamics Simulator (FDS) Version 6.5를 사용하여 실험 조건과 동일한 발열량을 가정하고 스프링클러헤드의 설치위치 및 손실인자(C-factor) 변화에 따른 작동 시간을 분석하였다. 그 결과 반응시간지수(Response Time Index, RTI)가 $100(m{\cdot}s)^{0.5}$이고 작동온도가 $72^{\circ}C$인 스프링클러는 화원 상층부의 기류 온도가 $100^{\circ}C$에서 $300^{\circ}C$로 상승하고, 기류의 속도가 약 0.7 m/s인 경우 C-factor = 0과 1일 때 스프링클러의 작동시간은 최소 30 s~60 s, C-factor = 3일 때 62 s에서 최대 92 s, C-factor = 5일 때 120 s 이상으로 나타났다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제24회 KOSCO SYMPOSIUM 논문집
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• pp.199-203
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• 2002

In this paper, the effects of water contents on combustion characteristics of paper sludge and capacity of fluidized bed combustor(FBC) were investigated using 0.26m diameter, 1.75m height pilot-plant scale combustor. Combustion tests of paper sludge containing water contents between 40wt% and 50wt% were performed. The temperature and emission variation, the pressure inside combustor were measured to monitor the fluidization quality. The experimental results showed that 30kg/hr feeding rate of sludge containing water up to 45wt% was preferable for this system. Sludge loading rate, heat release rate were calculated from experimental data as major parameters showing FBC capacity. Comparsion with sludge loading rate from other source was also performed

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.277-283
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• 2004

The time to ignition, heat release rate characteristics and carbon monoxide yield of fiber reinforced and sandwich phenol resin were investigated with cone calorimeter. The fire characteristics of unsaturated polyester, mostly being applied to the existing passenger train, and phenolic resin were compared. Thermal gravimetric analysis(TGA) was used to monitor the degree of thermal decomposition for the phenolic resin. According to the cone calorimeter data, the time to ignition, heat release rate and CO yield was faster and higher as the external heat flux increase. Under the same heat flux, the time to ignition of sandwich type phenolic resin was shorter than that of fiber reinforced. The result of comparison between unsaturated polyester and phenolic resin was that phenolic resin was shown to have better fire resistance than that of unsaturated polyester.