• Title/Summary/Keyword: combustion resistance

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Selection of the Best Oxygen Carrier for Chemical Looping Combustion in a Bubbling Fluidized Bed Reactor (기포유동층에서 케미컬루핑 연소시스템을 위한 최적 산소전달입자 선정)

  • Kim, Hana;Kim, Jung-Hwan;Yoon, Joo-Young;Lee, Doyeon;Baek, Jeom-In;Ryu, Ho-Jung
    • Clean Technology
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    • v.24 no.1
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    • pp.63-69
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    • 2018
  • The reduction reaction characteristics and physicochemical properties were studied for the selection of oxygen carrier, which is the core of the chemical looping combustion (CLC) technology. Fuel conversion and $CO_2$ selectivity of oxygen carrier according to the concentration of reducing gas and the reduction temperature using three kinds of oxygen carrier (SDN70, N018-R2, N016-R4) were measured and compared. In addition, Attrition Index (AI) and BET surface area were measured to analyze the attrition resistance and the surface characteristics of the oxygen carrier. As a result, it was confirmed that all three kinds of oxygen carrier were suitable for use in chemical roofing combustion system, and the best particle was determined to be N016-R4.

A Study on the Characteristic of Conversion Efficiency for Three-way Catalyst in Hydrogen-Natural Gas Blend Fueled Engine (수소-천연가스 혼합연료 엔진의 삼원촉매 전환효율 특성 연구)

  • Park, Cheol-Woong;Yi, Ui-Hyung;Kim, Chang-Gi;Lee, Janghee
    • Journal of the Korean Institute of Gas
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    • v.20 no.6
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    • pp.23-30
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    • 2016
  • The conventional natural gas engine realized lean combustion for the improved efficiency. However, in order to cope with exhaust gas regulations enforced gradually, the interest has shifted at the stoichiometric mixture combustion system. The stoichiometric mixture combustion method has the advantage of a three-way catalyst utilization whose purification efficiency is high, but the problem of thermal durability and the fuel economy remains as a challenge. Hydrogen-natural gas blend fuel (HCNG) can increase the rate of exhaust gas recirculation (EGR) because the hydrogen increases burning speed and lean flammability limit. The increase in the EGR rate can have a positive impact on heat resistance of the engine due to the decreased combustion temperature, and further can increase the compression ratio for efficient combustion. In this study, to minimize the exhaust emission developed HCNG engine with stoichiometric combustion method, developed three-way catalyst was applied to evaluate the conversion characteristics. The tests were carried out during the steady state and transient operating conditions, and the results were compared for both the conventional and proto-three-way catalyst of HCNG engine for city buses.

A Study on Perpendicular Flame Retardant Characteristic Improvement of Halogen-free Flame Retardant Compounds by Nanoclay Addition (나노클레이 첨가에 따른 할로겐프리 난연컴파운드의 수직난연 특성 향상에 관한 연구)

  • Hwang, Chan-Yun;Yang, Jong-Seok;Seong, Baeg-Yong;Kim, Ji-Yeon;Park, Dae-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.1
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    • pp.51-56
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    • 2015
  • The object of this study is to obtain the optimum mix proportion of halogen free compound with flame resistance and, for the purpose, thermal/electrical characteristics test are conducted using compatibilizing agents, flame resistance agents, hydroxide aluminum, sunscreen, antioxidant and silicon oil on the base resin of linear low density polyethylene (LLDPE), Ethylene vinyl acetate copolymer (EVA). Existing compound method accompanies many requirements to be satisfied including a lot of addition of flame resistance agents, prohibition of impact on mixing capability with base and property and etc. In this study, different from the existing method, the optimum mix proportion is determined and experimented by adding nano clay. Oxygen index test shows no difference between specimens while T-6, T-9 shows oxygen index of 29[%] and 26[%], respectively. This is concluded that hydroxide aluminum, which is a flame resistance agent, leads low oxygen index. From UL94-V vertical flame resistance test, the combustion behavior is determined as V-0, Fail based on UL94-V decision criteria. Viscometry shows low measurements in specimens with separate addition of compatibilizing agents or nano clay. Volume resistivity test shows low measurement mainly in specimens without compatibilizing agents. Therefore, with the flame resistance compound shows better performance for thermal/electrical property and the optimum mix proportion are achieved among many existing materials.

Study on the Particulate Matter Filtration Characteristics of the Metal Foam Particulate Filter (메탈 폼 입자 필터의 GDI 엔진 입자상 물질 정화 특성에 대한 연구)

  • Jang, Wonwook;Myung, Cha-Lee;Lee, Jeongmion;Park, Simsoo
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.347-348
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    • 2014
  • After-treatment system for gasoline direct injection engines should be considered due to the regulation standard for particle number emitted from spark ignition engine vehicles. A metal foam particulate filter, which is thought to be more proper for gasoline engines for its unique filtration and heat resistance characteristics, has been evaluated via engine dynamometer tests.

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Ablative Characteristics of Carbon/Carbon Composites by Liquid Rocket

  • Joo, Hyeok-Jong;Min, Kyung-Dae;Lee, Nam-Joo
    • Carbon letters
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    • v.2 no.3_4
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    • pp.192-201
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    • 2001
  • The Carbon/Carbon composite was prepared from 3D carbon fiber preform and coal tar pitch as matrix precursor. In order to evaluate of ablative characteristics of the composite, liquid rocket system was employed Kerosene and liquid oxygen was used as propellants, operating at a nominal chamber pressure of 330 psi and a nominal mixture ratio (O/F) of 2.0. The results of an experimental evaluation were that high density composite exhibited high, while low density composites showed low erosion resistance. The erosion rate against heat flux was highly depended on the density of the materials. The morphology of eroded fiber showed differently according to collision angle with heat flux on the composite. The granular matrix which derived from carbonization pressure of 900 bar was more resistance to heat flux than well-developed flow type matrix.

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A Study on the Thermal Response Characteristics of Carbon/Carbon Composites for Nozzle Throat Insert (노즐목 적용 탄소/탄소 복합재료의 열반응 특성 연구)

  • Ham Hee-Cheol;Bae Joo-Chan;Hwang Ki-Young;Kang Yoon-Goo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.162-166
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    • 2005
  • A thermal resistance estimation of carbon/carbon composites used as the nozzle throat insert of solid rocket motor was performed using TPEM motor. Three types of TPEM motor and two types of propellant were employed. The ablation rate is higher for the higher chamber pressure and also higher for the higher concentration of oxidizing species in combustion gas, but it is lower for the higher material density.

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A Study on the Material Properties of Grey Cast Iron for Cylinder Liner Treated by Thermo Plastic Deformation Process (열소성변형공정을 시행한 회주철제 실린더 라이너의 재료물성에 관한 연구)

  • Kim Tae-Hyoung;Kim Jong-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.6
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    • pp.671-677
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    • 2005
  • In internal combustion engines the usual material for the cylinder liner is because of its good wear resistance Apparently this wear resistance arises from the at iron to form a hard glazed surface when under sliding friction. When the cylinder liner wear limits, it shall be replace with new one according to the classification soci manufacturer's standards. However, adoption of alternative repairing method such a metalizing, thermo plastic deformation process became inevitable taking enormous cost renewal into consideration. In this paper. the material properties of cylinder liner of grey discussed on the basis of the results of experimental work of the thermo plastic deformation the worn out cylinder liner made of grey cast iron.

Incombustibility and Freezing-Thawing Resistance of Lightweight Polymer Concrete (경량 폴리머 콘크리트의 난연성 및 동결융해 저항성)

  • 채경희;최예환;연규석;이윤수;주명기
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.1
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    • pp.45-54
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    • 2003
  • The effects of binder content and silica sand content on the durability characteristics of lightweight polymer concretes are examined. As a result, the flame lingering times using unsaturated polyester resin and non-combustible polyester resin were 60∼120 and 0∼4 seconds respectively, and the combustion lengths were 9∼11 mm and 0∼3 mm, respectively. Thus it is believed that the lightweight polymer concrete was incombustible and the light weight polymer concrete in which non-combustible material was added was perfectly non-combustible. The percent of original mass of lightweight polymer concrete, according to the freezing-thawing experiment, was below 0.3 %, which was much less than that of cement concrete. The pluse velocity, for the case of the binder content 28 %, showed the minimum decreasing rate for the lightweight polymer concrete with silica sand content of 50 %. The higher the binder content, the greater the durability. That is much higher than other material and believed that the freezing-thawing was suppressed by a low absorption.

A Comparative Study of Tensile Strength of Architectural Membrane using Basalt Fiber (현무암섬유 기반 건축용 막재의 강도 비교 연구)

  • Kim, Ji-Hyeon;Shin, Hyeon-Uk;Song, Hun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.149-150
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    • 2016
  • The membrane structure is being applied in structures for various uses for its many advantages as permeableness, lightweightness, constructability, resource saving, and management cost reduction, and the usage is being expanded. However, despite the development of membrane structure, the standard for architectural membrane performance that considered fire safety is still inadequate. Therefore, this study applied basalt fiber with flame resistance on architectural membrane. Also, this study confirmed the membrane applicability of basalt fiber through comparison with existing architectural membrane.

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A Study on the Thermal Response Characteristics of Carbon/Carbon Composites for Nozzle Throat Insert (노즐목 적용 탄소/탄소 복합재료의 열반응 특성 연구)

  • Ham Hee-Cheol
    • Journal of the Korean Society of Propulsion Engineers
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    • v.10 no.1
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    • pp.30-37
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    • 2006
  • A thermal resistance estimation of carbon/carbon composites used as the nozzle throat insert of solid rocket motor was performed using TPEM motor. Three types of TPEM motor and two types of propellant were employed. The ablation rate is higher for the higher chamber pressure and also higher for the higher concentration of oxidizing species in combustion gas, but it is lower for the higher material density.