• 제목/요약/키워드: combustion charateristics

검색결과 11건 처리시간 0.021초

배기시스템 구성요소가 SI기관의 연소특성에 미치는 영향 (The effect of exhaust system components on combustion characteristics of SI engine)

  • 박경석;박세종;최석렬;손성만
    • 한국정밀공학회지
    • /
    • 제22권5호
    • /
    • pp.138-143
    • /
    • 2005
  • Recently, automobile manufacturers regarding stability, economic environmental-friendly problems by the development of automobile, environmental problem as designing the exhaust system. Increasingly strict environmental regulations to lower fuel consumption and reduce emission. Also to reduce the noise and the vibration of the automobile. According to develop variable type muffler, dual muffler and active intelligence exhaust system unit. Improvement in engine performance and fuel consumption rate demand information of pressure fraction and heat characteristics. To be able to determine these factor for we experiment on each case of exhaust system unit. In this study, how back pressure is distributed in flow-through in exhaust system and how to design exhaust system flexibleness, efficiency and combustion charateristics influenced by back pressure. This study furnish basic data for engineers, technicians.

다양한 성분을 가지는 천연가스의 연소특성 및 호환성 (Combustion characteristics and gas interchangeability of natural gas with various compositions)

  • 김종민;유병훈;이승로;이창언
    • 한국연소학회:학술대회논문집
    • /
    • 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
    • /
    • pp.89-91
    • /
    • 2012
  • In this study, an investigation into the gas interchangeability and combustion characteristics of natural gas with various compositions was performed. In order to suggest the appropriateness of gas interchangeability using the specific gravity(SG) and the Wobbe index(WI) values, combustion characteristics, which include incomplete combustion and flame lifting, were measured and observed for the upper and lower limits using the gas-oven as a domestic partial-premixed type appliance and the condensing boiler as a domestic premixed type appliance.

  • PDF

15kW급 미분탄 연소로내에서 바이오매스 혼소율 변화에 따른 연소 특성 비교 (Combustion Charateristics of Biomass Blends on a 15KW Pulverized Coal furnaces)

  • 이상민;성연모;최민성;문철언;최경민;김덕줄
    • 한국연소학회:학술대회논문집
    • /
    • 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
    • /
    • pp.41-44
    • /
    • 2014
  • This study focused on the effect of the biomass blended ratio on air-staged pulverized coal furnace. The hybrid NOx reduction technology between fuel blending and air staging has been applied in an air-staged pulverized coal fired furnace. The results indicated that co-firing biomass with coal could reduce NOx emissions in an air-staged combustion. In addition, carbon burnout and flame temperature increased under the air-staged condition. A dominant synergistic effect on NOx reduction and carbon burnout was observed when biomass co-firing with coal was applied in air staged combustion.

  • PDF

부분 예혼합 화염에서 연소실 압력이 연료별($CH_4$, $C_2H_4$, $C_3H_8$) 연소특성과 반응영역에 미치는 영향 (Influence of Changing Combustor Pressure on Combustion Characteristics and Reaction Zone in the Partially Premixed Flame with $CH_4$, $C_2H_4$ and $C_3H_8$)

  • 손제하;김종률;최경민;김덕줄
    • 한국연소학회지
    • /
    • 제16권3호
    • /
    • pp.33-40
    • /
    • 2011
  • Combustion experiments were conducted at three different fuels ($CH_4$, $C_2H_4$ and $C_3H_8$) to investigate the effects of combustor pressure (30 ~ -30 kPa) on combustion charateristics and reaction zone structure. Regardless of the fuels, emission index of CO (EICO) increased with decreasing combustor pressure, and EICO of $C_2H_4$ was mostly affected by changing combustor pressure at subatmospheric pressure. In order to observe reaction zone, $OH^*$, $CH^*$ and ${C_2}^*$ chemiluminescence intensity were measured. The sequence of the chemiluminescence intensity peak position was affected by chemical characteristics of fuels rather than changing combustor pressure. The emission zone thickness of $C_2H_4$ and $C_3H_8$, defined by the full width at half maximum (FWHM) of $CH^*$ intensity profile, were increased with decreasing combustor pressure. however, the thickness of $C_2H_4$ exhibited the opposite tendency due to the characteristics of the fuel as the bond structure.

4-Layer Slagging Model을 적용한 300 MW급 Shell형 1단 분류층 석탄 가스화기 전산수치해석 (Numerical Study on the 300 MW Shell-type One-stage Entrained Flow Coal Gasifier Apllied with 4-Layer Slagging Model)

  • 홍정우;정효재;송지훈;황정호
    • 한국연소학회지
    • /
    • 제17권1호
    • /
    • pp.1-11
    • /
    • 2012
  • A slag building simplified model was developed to determine wall heat flux of a Shell 300 MW coal gasifier. In the model 4 layers(particulate, sintered, molten slag, solidified slag) were considered and mass conservation and energy balance were used to obtain each slag layer's thickness and surface temperature. Thermo-chemical and fluid charateristics of the gasifier were studied with and without considering the slag model using commercial CFD code FLUENT. Consideration of the slag layer did not affect syn-gas mole fractions. However, the slag layer caused to increase the exit gas temperature by about 50 K.

공기 다단 분무연소기의 NOx 발생특성에 관한 실험적 연구 (Investigation of NOx Formation Charateristics in Multi Air Staged Spray Combustor)

  • 김한석;안국영;김호근;백승옥
    • 연구논문집
    • /
    • 통권31호
    • /
    • pp.23-43
    • /
    • 2001
  • An experimental investigation on the reduction of nitrogen oxide emission from swirling, turbulent diffusion flames was conducted using multi air staged combustor, The combustor utilizes swirler to dampen fuel/air mixing, allowing an extended residence time for fuel pyrolysis and fuel-N conversion chemistry in an locally fuel-rich environment prior to burnout. This process also allow to reduce thermal NOx formation to lessen the temperature of reaction zone. The aerodynamic process therefore emulates the conventional staged combustion process, but without the need for the physically separate fuel-rich and -lean stages. Parametric studies on the ratios of each staged air and droplet size were carried out the feasibility of fuel/air mixing for low NOx combustion with diesel and pyridine mixed diesel fuel oil.

  • PDF

Microwave에 의한 산성가스 분해 특성 (The Characteristics of Sour Gas Decomposition by Microwave)

  • 김동식;김재설;이동규
    • 공업화학
    • /
    • 제7권6호
    • /
    • pp.1027-1033
    • /
    • 1996
  • 쌍극자물질에 전자파를 조사하면 그 파동의 변화에 따라 분자가 진동하며, 이웃 분자와 마찰을 일으켜 물질 내부로부터 가열되는 독특한 현상을 보인다. 따라서 고체인 전자파흡수제에 흡착시킨 쌍극자 기체를 microwave energy로 쉽게 파괴할 수 있다. 연소기기 배출가스에서 산성가스 제거공정 개발을 위하여 이 방법에 의한 산성가스 분해실험을 실시하였다. Calcined char는 전자파흡수제 및 가스 흡착제로서의 역할을 하는데, NO와 $SO_2$를 함유한 표준가스를 char bed내로 통과시키면서 microwave를 조사하였다. Microwave가 조사되고 있는 20 gram의 char bed를 통과하는 동안 95% 이상의 NO와 70% 이상의 $SO_2$가 환경적으로 무해한 단체원소로 분해되었으며, 분해된 원소 중 산소기는 char의 기공내에서 탄소와 반응하여 $CO_2$를 형성하며 char의 기공도 및 표면적 증대효과를 가져왔다. 일반적인 상업적 연소공정에서 처럼 이보다 낮은 농도에서는 거의 완전한 분해가 가능하리라 보여지며, 대기오염 방지에 좋은 방법이 되리라 믿어진다.

  • PDF

메탄올 Bluff-Body 난류 화염내의 화염구조 및 $NO_{x}$ 생성 특성에 대한 수치적 연구 (Flamelet Modeling of Structures and $NO_{x}$ Formation Charateristics in Bluff-Body stabilized Methanol Flames)

  • 이준규;김성구;김용모;김세원
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2001년도 춘계학술대회논문집D
    • /
    • pp.37-42
    • /
    • 2001
  • This paper computes the bluff-body stabilized jet and flame. This study numerically investigates the nonpremixed $C_{2}H_{4}-air$ jet for the nonreacting case and the nonpremixed $CH_{3}OH-air$ turbulent flames for the reacting case using the laminar flamelet model on modified KIVA2 code. And this study predicts $NO_{x}$ formation characteristics using Eulerian Particle Flamelet Model. In the present study, the turbulent combustion model is applied to analyze both nonreacting and reacting case. And both standard $k-{\varepsilon}$ model and modified $k-{\varepsilon}$ model are used in nonreacting case. Calculations are compared with experimental data in terms of velocity, mixture fraction, mixture fraction Root Mean Square and Temperature. The present model correctly predicts the essential features of flame structures and $NO_{x}$ formation characteristics in the bluff-body stabilized flames.

  • PDF

초음속 난류 유동장내의 발사체 후방 동체형상에 따른 기저유동의 수치적 계산 (Numerical study of base flow of afterbodies for launch vehicle in supersonic turbulent flow)

  • 박남은;노형운;김재수
    • 한국전산유체공학회지
    • /
    • 제7권4호
    • /
    • pp.35-41
    • /
    • 2002
  • The projectile afterbodies for zero-lift drag reduction has been analyzed using the Navier-Stokes equations with the κ-εturbidence model. The numerical method of a second order upwind scheme has been used on an unstructured adaptive grid system. Base drag reduction methods that have been found effective on axisymmetric bodies are boattailing, base bleed, base combustion, locked vortex afterbodies and multistep afterbodies. In this paper, turbulence flow and pressure charateristics have been studied for geometries of multistep afterbodies. The important geometrical and flow parameters relevant to the design of such afterbodies have been identified by step number, length and height. The flow over multistep aftoerbodies or base have many kinds of compressible flow characteristics including expansion waves at the trailing edge, recompression waves, separation and recirculating flow in the base region, shear flow and wake flow. The numerical results have been compared and analyzed with the experimental data. The flow characteristics have been clearly shown.

압력선회노즐에서 물-기름 유화연료의 분무특성 (Spray Charateristics of Water/Oil Emulsified Fuel in Pressure-Swirl Nozzle)

  • 임정현;노수영
    • 한국분무공학회지
    • /
    • 제5권1호
    • /
    • pp.5-12
    • /
    • 2000
  • The beneficial aspects of applying emulsion fuels to combustion systems may be due to the changes of fuel properties which lead to the enhanced atomization characteristics. The spray characteristics of water/oil emulsified fuel injected from the pressure-swirl(simplex) atomizer using for oil burner were investigated. Four different water contents from 10 to 40 % by volume at 10% increment were prepared by mixing with the different contents of surfactants. Total amount of surfactant used was varied from 1 to 3 % by volume. This study demonstrates the influence of water and surfactant contents of emulsified fuel, injection pressure on the spray characteristics, i.e. Sauter mean diameter(SMD) and spray angle. The drop size distribution of the emulsified fuel spray was measured with a Malvem particle sizer. In order to measure the spray angle, the digital image processing was employed by capturing multiple images of the spray with 3-CCD digital video camera. It was evident that the addition of water and surfactant changes fuel properties which are the key parameters influencing the atomization of the spray. The increase in surfactant content results in the decrease of SMD and the increase in spray angle. The droplets decease with increase in injection pressure, but the influence of injection pressure in this experimental condition was less important than expected. The more viscous fuel with the increase of water content exhibits the larger droplets in the centerline of the spray, and the less viscous fuel in the outer edges of the spray. The increase in axial position from the nozzle causes the spray angle to decrease. The spray angle decreases with increase in water content. This is due to increase in viscosity with increase in water content.

  • PDF