• Title/Summary/Keyword: combustion times

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Performance Evaluation on the Addition of Low-pressure Loop EGR in a Commercial Diesel Engine (상용 디젤엔진의 저압 순환 EGR 추가에 대한 성능 평가)

  • Wang, Tae-Joong;Lee, Jong-Yoon;Shim, Eui-Joon;Kim, Duk-Sang;Lee, Dong-In
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.2
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    • pp.105-110
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    • 2011
  • Through this study, the performance evaluation on the addition of low-pressure loop EGR(Exhaust Gas Recirculation) in a 6.0 L commercial diesel engine was carried out using WAVE modeling and simulation. Since the key technology of advanced diesel engine combustion such as low-temperature combustion is to steadily supply high rates of EGR in a wide operating range, the current study could be effectively contribute to the design and development processes of up-to-date diesel engine systems as real-world reference data. The current simulation results show that the system in which low-pressure loop EGR is added shows almost 2.3 times increase in maximum EGR rate at 1000 rpm as well as almost 1.6 times increase at 2200 and 1600 rpm in comparison with an engine system employing high-pressure loop EGR only. Also, both turbocharger axis speed and charging pressure level did not deteriorate due to the addition of low-pressure loop EGR at 2200 and 1000 rpm, but they were fairly decreased at 1600 rpm.

A Study On Combustion Characteristics of Automobile Interior (자동차 내장재의 연소 특성에 관한 연구)

  • Kim, Jeong-Hun;Park, Hyung-Ju;Kim, Hong
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1996.11a
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    • pp.43-48
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    • 1996
  • It is considered that automobile inner space is dangerous due to its combustion characteristics. (Automobile interior is largely made by plastic materials.) At last it is necessary to study on combustion characteristics of automobile interior. we could obtain its rapid combustion velocity and high smoke density by using ASTM D 2863 apparatus, DSC (Differential Scanning Calorimetry), Smoke density apparatus and so on. The study is summerized by following conditions and results. 1. Sample size was 150mm(length)$\times$60mmwidth). 2. Combustion velocity appeared peak point in the 2cm point. 3. PVC and foam layers are important factors in the face of smoke density. 4. Using DSC, we obtained the point that automobile interior was melted. 5. Automobile interior should be improved because of its low L.O.I value and rapid flame propagation velocity.

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Combustibility Improving Effect of Organometallic Salt for Fuel Oil (燃料油 燃燒에 미치는 有機金屬鹽의 助燃效果)

  • Yong Shik Kang
    • Journal of the Korean Chemical Society
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    • v.15 no.6
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    • pp.330-347
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    • 1971
  • Catalytic effects of metallic salts on the combustion of diesel fuel oil have been studied. In the case of organometallic salt, the active species are the metallic oxides resulted from combustion of the salts. The oxides act only on the residual solid carbon produced from the fuel oil combustion. The catalytic activity can be explained with the semiconductor theory just as in the case of the gas phase reaction. The chemical rate constant of the combustion of carbon, the soot from diesel fuel oil, is found to be $k_c=1.1{\times}10^4\;exp$ (-16,600/T) below $800^{\circ}K$. By addition of metallic oxides, the rate constant increases remarkably. This work has substantiated the belief that the effect of the metallic salts on the fuel oil combustion can conveniently be studied by checking directly the effect of the corresponding metallic oxide on the soot carbon.

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Finite Element Analysis of Combustion Reaction on Iron and Metal Oxides Interface (Fe-금속 산화물 계면에서 연소반응의 유한 요소해석)

  • Gu, Mun-Seon;Choe, Yong
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.118.2-118.2
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    • 2017
  • Combustion behavior of Fe, CuO, NiO, ZnO and $Fe_2O_3$ powder mixture was carried out by finite element method (FEM) to understand a reaction at iron and metal oxide interface. The FEM was done by using ANSYS Fluent 17.0. Initial and boundary conditions are 1 atmosphere, room temperature, 0.1MPa of oxygen partial pressure, $T_{S1}=1127^{\circ}C$, $T_{S2}=327^{\circ}C$ for a cylindrical shape specimen with dia. $35{\times}80$ [mm]. The maximum combustion temperature is $1537^{\circ}C$ for the condition of conduction, convection and radiation. The combustion temperature and rate are about $847^{\circ}C$ and 3.9mm/sec, respectively. The combustion wave is enough to make ternary ferrite phase like $CuNiZnFe_2O_3$.

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Ignition behaviour of pulverized coal particle during coal combustion (미분탄 연소의 점화 특성에 관한 연구)

  • Li, Dongfang;Kim, Ryang Gyoon;Song, Ju Hun;Jeon, Chung-Hwan
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.213-215
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    • 2012
  • As one of the primary fuel sources, oxy-fuel combustion of coal is actively being investigated because of the climate changing problem such like the emission of green house gases. In this paper research about the pulverized coal technology, which is widely used in both power-generating and iron-making processes was studied to invesgate the ignition behaviour of pulverized coal particles during coal combustion as changing the ambient oxygen concentration of the particle. The ignition phenomenon of the coal particles fed into a laminar flow reactor was imaged with a Integrated charged-coupled device (ICCD) camera. The ignition points were determined throught the analysis of the images, and then the ignition delay times were able to be calculated. The experiment results show that a lower oxygen concentration increases the ignition delay time.

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An Experimental Study on Combustion Behavior of Different Ranks of Coals and Their Blends (저등급탄과 혼탄의 연소거동에 관한 실험적 연구)

  • Moon, Cheoreon;Sung, Yonmo;Ahn, Seongyool;Kim, Taekyung;Choi, Gyungmin;Kim, Duckjool
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.205-208
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    • 2012
  • In this study, the thermal behavior and combustion characteristics of different ranks of coals and their blends were investigated to obtain information necessary for the evaluation of the co-processing of blends with low-rank coals. Thermogravimetric analysis(TGA) and differential thermal analysis(DTA) were carried out at different temperature from ambient temperature to $800^{\circ}C$, and a laboratory-scale pulverized coal combustion burner was used with coal feeing rate of $1.04{\times}10^{-4}kg/s$.

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Combustion Qualities of Waste Tire Oil as Substituting Light Oil for Greenhouse Heating (시설농업난방 경유대체유로서 폐타이어오일의 연소 특성)

  • 김영중;유영선;강금춘;이건중;윤진하
    • Journal of Biosystems Engineering
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    • v.25 no.6
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    • pp.481-488
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    • 2000
  • This study was initiated in order to find alternative fuel substituting for light oil the most common fuel for heating greenhouse. The tire oil used in this research was produced by pyrolysis process, one of the final products besides steel string and carbon black in which waste tires as a form of chopped pieces broken by shredding machine are heated up to 200~30$0^{\circ}C$ with maximum restraining of oxygen supply. In order to justify light oil equivalent qualities in tire oil combustion characteristics were defined in the way of comparing kinetic viscosities in the wide range of temperature flame sizes and exhaust gas components in the various combustion conditions. We found that kinetic viscosity of tire oil was lower than light oil by 1 to 2 cSt in the temperature range showing better flowing mobility in the fuel line of the burner and no significant difference in flame size between the two oils in the all combustion treatments. However much more NO and SO$_2$ were detected from the exhaust gases of tire oil than light oil combustions. In fact tire oil contains more nitrogen and total sulfur, by 25 times and 40 times respectively than light oil according to the composition analysis. Tolerable limit for SO$_2$discharge amount defined by the national air pollution standards is under 540ppm so tire oil combustion satisfies the requirement though. It is desirable if sulfur and nitrogen filtering process shall be added in the tire oil production line. Except the exhaust gas components all greenhouse heating qualities of tire oil including hot air temperature are very identical to those of light oil.

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Thermal Effects in the Pool Fire of Fuels(I) (석유류 POOL FIRE에 있어서의 열적인 영향(I))

  • 정국삼;강민호;이덕영
    • Journal of the Korean Society of Safety
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    • v.11 no.1
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    • pp.75-83
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    • 1996
  • This paper was concerned with pool fire about many used kerosene and diesel oil. In order to know the thermal effects of kerosene and diesel oil, temperature change in the pool fire of these fuels were obtained as a variation of combustion time and the tank's height and diameter by using the data acquisition system, And fuel combustion velocity were derived as a function of the diameter and wall thickness of tanks and combustion time. As a result, when the tank's height was 15㎝, the greater diameter the higher temperature rising regardless of tank's wall thickness and fuels. But, when the tank's height is 30㎝, temperature rising was not higher than 15㎝. Also, temperature rising in the pool fire of kerosene much higher than diesel oil. Kerosene's combustion velocity was about two times faster than diesel oil. And, kerosene's combustion velocity was increased according to the increasing of tank's diameter and combustion time. But, diesel oil's combustion velocity was a little increased or not. Surrounding temperature change of tank with the pool fire was obtained temperature distribution of 0∼35℃ according to the change of tank's diameter and distance from the tank's wall.

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Open-Loop Control of Combustion Instability in Hot-Firing Test Using Gaseous Hydrocarbon Fuel (기체 탄화수소 연료 연소시험에서 연소불안정의 개루프 제어)

  • Hwang, Donghyun;Ahn, Kyubok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.6
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    • pp.28-36
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    • 2018
  • A study was conducted to apply open-loop control to the combustion instability in a dump combustor using gaseous hydrocarbon fuels. Control power and frequency were varied by employing a loudspeaker under combustion conditions with similar characteristic chemistry times of the fuels. In the case of open-loop control where the frequency was identical to the combustion instability frequency, the open-loop control power affected the control performance. Results obtained from conducted open-loop control tests, where the frequency was different from the combustion instability frequency, show that setting the open-loop control frequency similar to the combustion instability frequency is effective.

Toxicity Evaluation of the Combustion Products from Synthetic Wood as Internal Finish (건축물 내부 마감재인 합성목재별 연소가스 독성평가)

  • Kim, Jong-Buk;Lee, Si-Young
    • Fire Science and Engineering
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    • v.30 no.2
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    • pp.7-18
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    • 2016
  • This study evaluated the toxicity of the burning gas from the synthetic wood products used in housings or warehouses. The combustion products of five materials, viz. impregnated laminated board, MDF, Douglas fir plywood, core plywood, and Lauan retardant, were analyzed using SEM, FTIR and a Cone Calorimeter. For the Lauan retardant, 256,965 ppm of carbon dioxide ($CO_2$) and 1,475 ppm of sulfur dioxide ($SO_2$) were measured, which are 2.5 times and 3.6 times as high as their lethal concentrations of 100,000 ppm and 400 ppm, respectively. For the impregnated laminated board, 1,569 ppm of nitrogen dioxide ($NO_2$) was measured, which is 6 times as high as its lethal concentration of 250 ppm. For MDF, 795 ppm of ammonia ($NH_3$) was measured, which is higher than its lethal concentration of 750 ppm. As a result, most internal-finishes generated toxic combustion products at levels higher than their lethal concentrations, which underlines the importance of the selection and manufacturing of internal-finish materials.