• Title, Summary, Keyword: 연소반응

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Reactivity of Coal Char Gasification with $CO_2$ at Elevated Pressure (가압하 석탄 촤의 $CO_2$ 가스화 반응성 연구)

  • 박호영;안달홍;김시문;김종진
    • Journal of Energy Engineering
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    • v.12 no.3
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    • pp.231-240
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    • 2003
  • Reactivity of Char-CO$_2$ gasification of five coals for power generation was investigated with PTGA in the temperature range 850∼1000$^{\circ}C$ and the pressure range 0.5∼2.0 MPa. The effect of coal rank, initial char characteristics and pressure on the reaction rate was evaluated for five chars. The reactivity of low lank coal char was better than that of high rank coal char, and this could be explained with the initial pore structure and surface area of char. Meso/macro-pores of char seems to markedly affect char reactivity by way of providing channels for diffusion of reactant gas into the reactive surface area. For the range of tested pressure, the reaction rate is proportional to CO$_2$ partial pressure and the reaction order ranges from 0.4 to 0.7 for five chars. The effect of total pressure on the reaction rate was small, and kinetic parameters, based on the unreacted core model, were obtained for five chars.

흑연의 연소

  • 한국원자력산업회의
    • Nuclear industry
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    • v.7 no.9
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    • pp.57-65
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    • 1987
  • 소련의 체르노빌원자력발전소에서 사고가 발생한지도 거의 1년반이 되고 있다. 이 사고에서는 중성자감속재로 사용되고 있던 흑연블록의 연소가 피해를 크게 했다고 한다. 본고에서는 흑연의 연소, 즉 가스화반응을 총괄하였다.

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Study on the Combustion Performance Estimation of Hydrazine Mono Propellant Thruster (하이드라진 단일 추진제 추력기의 연소 성능예측에 관한 연구)

  • 정인석;윤영빈;최정열;김철중;명대근;정기훈
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.30-30
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    • 1998
  • 다목적 실용위성의 자세 제어용으로 장착되는 하이드라진 단일 추진제 추력기의 연소성능 특성을 살펴보았다. 일차적으로, 연소기내의 화학 평형 계산을 통하여 하이드라진 연소 생성물인 암모니아의 분해율과 초기 엔탈피 수준에 따른 추력기의 성능 특성을 살펴보았다. 다음 순서로, 연소기 내의 비평형 화학 반응 계산을 통하여 연소진행 시간에 화학 조성 및 성능 특성을 살펴 볼 수 있었으며, 최종적으로, 점성 및 비점성, 동결 및 비평형 화학 반응 해석에 따른 성능 특성 변화를 살펴보았다. 본 연구 결과로부터 각 작동 변수에 따른 추격기 성능 특성의 변화를 이해할 수 있었으며, 이는 단일 추진제 추력기 연소실의 구성, 설계 및 추력기의 운용 조건 설정에 중요한 자료로 이용될 수 있을 것으로 기대된다.

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Combustion Characteristics According to the Equivalence Ratio of Hydrocarbon Fuel/Air Premixture Excited by Ultrasonic Standing Wave (정상초음파가 인가된 탄화수소계 연료/공기 혼합물의 당량비에 따른 연소특성)

  • Kim, Min Cheol;Bae, Seong Hun;Hong, Joon Yeol;Kim, Jeong Soo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.628-631
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    • 2017
  • An experimental study of the combustion characteristics according to the equivalence ratio of hydrocarbon fuel/air premixture excited by ultrasonic standing wave are presented. The image of the propagating flame was acquired using a high-speed camera, and the combustion characteristics of each fuel were closely observed through image processing. it was conformed that ultrasonic standing wave has been found to stimulate the combustion reaction in the stoichiometric ratio.

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Fabrication of Nano-sized ZnO Colloids from Spray Combustion Synthesis (SCS) (분무연소합성(SCS)법에 의한 나노크기 산화아연(ZnO) 콜로이드의 제조)

  • Lee, Sang-Jin;Lee, Sang-Won;Jun, Byung-Sei
    • Journal of the Korean Ceramic Society
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    • v.41 no.1
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    • pp.76-80
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    • 2004
  • Nano-sized ZnO colloids were prepared by use of spray combustion method. for combustion reaction, $Zn(NO_3)_2{\cdot}6H_2O$ and $CH_6N_4O$ were employed as an oxidizer and a fuel. Exothermic peak was shown at $230^{\circ}C$ by DTA/TGA, and it was considered as a combustion reaction followed by ignition of the precursor mixture. In case of spray combustion method, because insufficient contents of molecules and radicals generated from precursor droplets may lead an incomplete igmition, the ignition temperature of combustion chamber was chosen at $500^{\circ}C$. For diminishing aerosol coagulation, the droplet number concentration was reduced by filter media. The fluid was laminar with 2.5 seconds of aerosol residence time. The synthesized colloids had spherical shape with 180 nanometer size, and the crystalline phase was ZnO with hexagonal structure.

Conceptual Design of 50 kW thermal Chemical-Looping Combustor and Analysis of Variables (열량기준 50kW급 매체순환식 가스연소기의 개념설계 및 변수해석)

  • 류호정;진경태
    • Journal of Energy Engineering
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    • v.12 no.4
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    • pp.289-301
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    • 2003
  • To develop a chemical-looping combustion technology, conceptual design of 50 kW thermal chemical-looping combustor, which is composed of two interconnected pressurized circulating fluidized beds, was performed by means of mass and energy balance calculations. A riser type fast fluidized bed was selected as an oxidizer and a bubbling fluidized bed was selected as a reducer by mass balance for the chemical-looping combustor. Calculated values of bed mass, solid circulation flux, and reactor dimension by mass and energy balance calculations were suitable for construction and operation of chemical-looping combustor. It is concluded from the comparison of the design results and operating values of commercial circulating fluidized bed that the process outline is realistic. Moreover, the previous results support that oxygen carrier particle, NiO/bentonite, fulfills the conversion rates needed for the proposed design. The effects of system capacity, metal oxide content in a oxygen carrier particle, amount of steam input, gas velocity, and solid depth on design values were investigated and the changes in the system performance can be estimated by proposed design tool.

초임계 난류연소 모델링

  • Park, Tae-Seon
    • Journal of the KSME
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    • v.56 no.9
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    • pp.32-37
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    • 2016
  • 초임계 유체의 고유한 물리적 특성변화와 난류유동을 결합하여 성능을 높이는 데 활용하고 있는 가장 대표적인 시스템 중의 하나는 연소기이다. 이때 연료와 산화제의 연소반응은 저압조건과 다른 고유한 특성을 가지고 있어 기존의 연소모델에 의해서는 정확한 분석이 어렵게 된다. 따라서 초임계 압력조건에 대한 연소과정을 분석할 수 있는 연소모델이 필요하고 이러한 연소과정이 난류유동조건에서 발생하기 때문에 최근 많은 연구가 초임계 난류연소모델 개발에 집중되어 왔다. 이 글에서는 특히 액체로켓엔진 관련 초임계 연소모델 개발 분야의 연구동향을 살펴보고자 한다.

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A Study on the Combustion Characteristics over Pd/cordierite Catalyst (Pd/cordierite 촉매상에서 메탄의 연소 특성 고찰)

  • Cho, Won-Ihl;Oh, Young-Sam;Park, Dal-Ryung;Baek, Young-Soon;Pang, Hyo-Sun;Mok, Young-Il
    • Journal of Energy Engineering
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    • v.6 no.1
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    • pp.34-40
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    • 1997
  • This study aims to investigate the application possibility on natural gas in relation to the catalytic combustion of methane on Pd/cordierite catalyst which is currently used as an automobile converter catalyst. The surface area of the catalyst tested was determined to be about 18.7㎡/g and to keep stable condition in structure at mid-high temperatures. The activation energy for methane combustion reaction was estimated to be 19.2 kcal/mol and a hysterisis on the catalyst activity was observed in terms of the catalyst deactivation as the reaction temperature was varied for the methane combustion. On Pd/cordierite catalyst, The characteristics of methane combustion were studied as functions of space velocity and air/fuel ratios below 700$^{\circ}C$.

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