• 제목/요약/키워드: Combustion Load

검색결과 402건 처리시간 0.022초

터보과급 디이젤기관의 성능에 관한 실험적 연구 (An Experimental Study on the Performance of Turbocharged Diesel Engine)

  • 채재우;정성찬;백중현
    • 한국자동차공학회논문집
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    • 제2권6호
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    • pp.76-86
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    • 1994
  • Combustion of diesel engine depends on the mixing of air and evaporating fuel during ignition delay greatly. Variation of air-fuel mixing rate and ignition delay for engine operating condition causes difference of combustion, performance and exhaust emissions. This study is investigated in a turbocharged diesel engine of IDI swirl chamber type. In the results, As injection timing is advanced until $12.6^{\circ}$ BTC, ignition delay decreases. NOx concentration and smoke level in exhaust gas increases for advanced injection timing Ignition delay, combustion period, pressure rise rate and exhaust gas temperature are increased with increasing engine speed. And ignition delay at high load is more decreased than that at low load. Ignition delay and combustion period are decreased with increasing intake pressure. Power increases, temperature and CO, NOx concentration in exhaust gas decreases as intake pressure increases. With increasing load, ignition delay is decreased and combustion period, motoring pressure are increased.

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니켈합금 Metal Foam을 적용한 예혼합 버너의 연소특성 (Combustion Characteristics of Premixed Combustor using Nickel Based Metal Foam)

  • 이필형;황상순;김종광
    • 한국연소학회지
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    • 제22권2호
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    • pp.42-49
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    • 2017
  • A premixed combustion has many advantages including low NOx and CO emission, high thermal efficiency and a small volume of combustor. This study focused on combustion characteristics in a premixed combustion burner using the nickel based metal foam. The results show that the blue flame is found to be very stable at heating load 6,300-25,200 kcal/h by implementing the proper nickel based metal foam and baffle plate. The premixed flame mode is changed into green flame, red flame, blue flame and lift off flame with decreasing equivalence ratio. NOx emission was measured 80 ppm(0% oxygen base) from 0.710 to 0.810 of equivalence ratio and CO emission is 90 ppm(0% oxygen base) under the same equivalence ratio. It is also found that the stable blue flame region in flame stability curve becomes wider with increasing the heat load.

저온연소엔진 실용화를 위한 연소전략에 대한 연구 (Investigation of Combustion Strategy for Commercialization of Low Temperature Diesel Combustion Engine)

  • 심의준;한영덕;신승협;김득상;권상일
    • 한국자동차공학회논문집
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    • 제22권6호
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    • pp.120-127
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    • 2014
  • Robustness and controllability are the key factors in internal combustion engine commercialization. This study focuses on the combustion strategy to commercialize the low temperature diesel combustion technology. Various LTC combustion methods such as PPCI, MK and highly diluted mixing controlled LTC were conducted on 6.0L heavy duty diesel engine. To find the best feasible LTC strategy, emission level, fuel consumption and combustion safety during the combustion mode change were considered. Experiments were carried out under various engine operating conditions; engine speed & load, EGR level, injection timing. Finally, this study suggests realizable LTC combustion strategy; moderate EGR level and slight early injection are possible to considerably lower PM, NOx emission and expand LTC operating range up to 50% load without CO and HC emission.

발전용 희박예혼합 가스터빈에서 연소모드변환 시기의 연소특성 해석 (Numerical Analysis of Combustion Characteristics during Mode Transfer Period in a Lean Premixed Gas Turbine for Power Generation)

  • 정재화;서석빈;김종진;차동진;안달홍
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.279-282
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    • 2002
  • Recently, gas turbines for power generation adopt multistage DLN(Dry Low NOx) type combustion, where diffusion combustion is applied at low load and, with increase in load, the combustion mode is changed to lean premixed combustion to reduce NOx emissive concentration. However, during the mode changeover from diffusion to premixed flame, unfavorable phenomena, such as flashback, high amplitude combustion oscillations, or thermal damage of combustor parts could frequently occur. In the present study, to apply for the analysis of such unfavorable phenomena, three-dimensional CFD investigations are carried out to compare the detailed flow characteristics and temperature distribution inside the gas turbine combustor before and after combustion mode changeover. The fuel considered here is pure methane gas. A standard $k-{\varepsilon}$ turbulence model with wall function and a P-N type radiation heat transfer model, have been utilized. To analyze the complex geometric effects of combustor parts on combustion characteristics, fuel nozzles, a swirl vane f3r fuel-air mixing, and cooling air holes on the combustor liner wall, are included in this simulation.

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이산형 열-음향 모델을 이용한 부하 변동시 가스터빈 연소 불안정 특성 (Combustion Instability of Gas Turbine with Segmented Dynamic Thermo-Acoustic Model under Load Follow-Up)

  • 정지웅;한재영;정진희;유상석
    • 한국수소및신에너지학회논문집
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    • 제29권5호
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    • pp.538-548
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    • 2018
  • The thermo-acoustic instability in the combustion process of a gas turbine is caused by the interaction of the heat release mechanism and the pressure perturbation. These acoustic vibrations cause fatigue failure of the combustor and decrease the combustion efficiency. This study is to develop a segmented dynamic thermo-acoustic model to understand combustion instability of gas turbine. Therefore, this study required a dynamic analysis rather than static analysis, and developed a segmented model that can analyze the performance of the system over time using the Matlab/Simulink. The developed model can confirm the thermo-acoustic combustion instability and exhaust gas concentration in the combustion chamber according to the equivalent ratio change, and confirm the thermo-acoustic combustion instability for the inlet temperature and the load changes. As a result, segmented dynamic thermo-acoustic model has been developed to analyze combustion instability under the operating condition.

디젤 기관의 연소와 배출물에 관한 연구 -경유-물물의 유화연료 사용시- (A Study on Combustion And Exhaust Emissions of Diesel Engine -For Gas Oil-Water Emulsified Fuel-)

  • 조진호;김형섭;박정률
    • 대한기계학회논문집
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    • 제16권1호
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    • pp.180-188
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    • 1992
  • 본 연구에서는 와류실식 디젤 기관에 경유-물의 유화연료 사용시 시관의 회전 속도(1500rpm)가 일정인 경우 물의 첨가량(체적비, 0~20%)과 기관의 부하(BMEP,2.1~ 7.5kg/$\textrm{cm}^2$)변화에 따른 연소실내 압력, 압력상승률 및 열발생률, 착화지연 기간, 연료 소비율 등의 연소특성과 CO, HC, NOx 및 매연의 배출능도 등 유해 배출 가스에 미치는 영향에 관하여 실험적으로 구한 것이다.

자연흡기식 디젤 기관의 연소와 매연 배출 특성에 관한 실험적 연구 (A Study on the Combustion and Smoke Emission Characteristics of the Natural Aspiration Type Diesel Engine)

  • 정우인;박찬국
    • 한국자동차공학회논문집
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    • 제5권4호
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    • pp.70-83
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    • 1997
  • We made a selection of engine operating conditions in the natural aspiration type diesel engine as load and speed. The effects on the power, smoke emission and cylinder pressure characteristics of these variations in operating conditions were observed experimentally. Also, the smoke emission was predicted by using the Arrhenius equation and empirical equation of the smoke emission was made. At the same time, the correlations, between the combustion and smoke emission characteristic were examined. From the above results, it is clear that to prevent power dropping and to decrease exhaust fume whin the conditions are changed, one should improve the intake system. To do this, the best way is to lower the air-fuel mixing ratio. We found that the parameters of the indicated mean effective pressure, maximum pressure and its location and combustion duration, etc. change the motion in accordance with the conditions described above. Also, we found that the variation of the pressure cycle comes from an amplified variation of the early part of process. From the analysis of comparing combustion and exhaust fume, the exhaust fume is produced at the latter time of combustion and decreased when the combustion ratio is higher. Also, we developed a special formula which can predict the exhaust fume value according to the engine load and speed.

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중질유-물 유화연료의 연소특성 평가 (An Evaluation on the Combustion Characteristics of Heavy Oil-Water Emulsions)

  • 이용일
    • 대한기계학회논문집B
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    • 제26권12호
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    • pp.1722-1728
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    • 2002
  • Most researches regarding emulsified fuel were in the areas of emulsifier, emulsified fuel manufacturing and emulsified fuel droplet combustion, but there were little papers published regarding emulsified fuel combustion and boiler efficiency in an industrial boiler. The main purpose of this study is to clarify whether improvements in the boiler efficiency and the reduction of pollutants such as CO, NOx, SOx and smoke exist or not when emulsified fuels are combusted in the commercial boiler. Main experimental parameters were water content in heavy oil , excess $O_2$, and boiler load. The fuels used in this experiment were 0.5 B-C, and 5 kinds of 0.5 B-C/water emulsified fuels. The combustion characteristics of heavy oil and its emulsions with water were investigated in an industrial boiler. The combustion stability was monitored and exhaust gases such as CO, NOx, SOx and smoke were measured with excess $O_2$ and combustion load. In case of emulsified fuel combustion, flame stability was poor and boiler efficiency was lowered by 1.6~5.7%, but emission levels of CO and smoke were improved.

가솔린 엔진의 밸브타이밍 변화가 부분부하 조건에서 잔류가스량 및 연소특성에 미치는 영향 (Effect of Value Timing on Residual Gas Fraction and Combustion Characteristics at Part Load Condition in an SI Engine)

  • 김철수;송해박;이종화;유재석;조한승
    • 한국자동차공학회논문집
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    • 제8권4호
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    • pp.26-33
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    • 2000
  • In-cylinde flow and mixture formation are key contributors to both idle stability and combustion stability at part load condition in SI engine. The real time measurements of air-fuel ration and in- cylinder residual gas fraction are particularly important to obtain a better understanding of the mechanisms for combustion and emissions especially during cold start and throttle transient condition. This paper reports the cycle resolved measurements of residual gas fraction and equivalence ration near speak plug with value timing change and their effects on combustion characteristics at part load. The results showed that the effect of intake value opening on the residual gas fraction was smaller than that of exhaust valve closing because of the decreases of exhaust gas reverse flow from exhaust port. The variation of equivalence ratio near spark plug increased with the increase of value overlap and it closely related with heat release rate and combustion stability

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가솔린 균일 예혼합 압축 착화 디젤기관의 연소 및 배기 특성에 미치는 운전조건의 영향 (Effect of Operation Condition on the Characteristics of Combustion and Exhaust Emissions in a Gasoline Fueled HCCI Diesel Engine)

  • 이창식;김명윤;황석준;김대식
    • 한국자동차공학회논문집
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    • 제12권1호
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    • pp.48-54
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    • 2004
  • The purpose of this work is to investigate the effect of premixing condition on the combustion and exhaust emission characteristics in a HCCI diesel engine. To from homogeneous charge before intake manifold, the premixed gasoline fuel is injected into a premixed tank by fuel injection system and the premixed gasoline fuel is ignited by direct injected diesel fuel. Experimental result shows the NOx and soot emissions are decreased linearly with the increase of premixed ratio. In the case of intake air temperature $20^{\circ}C$ with light load, the specific fuel consumptions are increased with the rise of premixed ratio and HC and CO emissions are also increased. But the intake air heating can improve the specific fuel consumption at light load condition because increased air temperature promotes the combustion of premixed mixture. In the case of high intake air temperature with high load condition, premixed fuel is auto-ignited before diesel combustion and soot emission is increased.