• 제목/요약/키워드: Combustion engines

검색결과 755건 처리시간 0.022초

내연기관의 연소실험을 위한 신형 급속 압축-팽창 장치의 개발 (Development of a New Rapid compression-Expansion Machine for Combustion Test of Internal Combustion Engine)

  • 배종욱
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2000년도 춘계학술대회 논문집(Proceeding of the KOSME 2000 Spring Annual Meeting)
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    • pp.45-51
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    • 2000
  • Investigators who study on combustion in the cylinders of reciprocating piston type internal combustion engines have been encountered embarrassments due to the difficulties of adjusting specific parameter without interfacing other parameters such as cylinder wall temperature composition of gas in the cylinder existence of cylinder lubricant etc. Rapid compression-expansion machine the position and speed of piston of which are able to be controlled by means of a system controlled electrically and speed of piston of which are able to be controlled by means of a system controlled electrically and actuated hydraulically could be utilized as one of the most preferable countermeasures against those difficulties. Several units of rapid compression-expansion machines were developed but the speed up of frequency of piston movement still is the problem to be improved to cope with actual speed of internal combustion engines. Authors designed and manufactured a new rapid compression-expansion machine electrically controlled hydraulically actuated and computer programed and then examined the performance of one. Results of a set of experiments revealed acquirements of certain improvement of frequency of piston movement preserving the stability of system response and reproducing accurate compression ratio of cylinder those are the key function for the in-cylinder combustion experiments of internal combustion engines.

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내연기관의 연소실험을 위한 신형 급속 압축-팽창 장치의 개발 (Development of a New Rapid Compression-Expansion Machine for Combustion Test of Internal Combustion Engine)

  • 정남훈;배종욱
    • Journal of Advanced Marine Engineering and Technology
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    • 제24권5호
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    • pp.69-75
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    • 2000
  • Investigators who study on combustion in the cylinders of reciprocating piston type internal combustion engines have been encountered embarrassments due to the difficulties of adjusting specific parameter without interfacing other parameters such as cylinder wall temperature, composition of gas in the cylinder, existence of cylinder lubricant etc. Rapid compression expansion machine, the position and speed of piston of which are able to be controlled by means of a system controlled electrically, and actuated hydraulically could be utilized as one of the most preferable countermeasures against those difficulties. Several units of rapid compression expansion machines were developed but the speed up of frequency of piston movement still is the problem to be improved to copy with actual speed of internal combustion engines. Authors designed and manufactured a new rapid compression-expansion machine electrically controlled, hydraulically actuated, and computer programed and then examined the performance of one. Results of a set of experiments revealed acquirements of certain improvement on frequency of piston movement preserving the stability of system response and reproducing accurate compression ratio of cylinder, those are the key function for the in-cylinder combustion experiments on internal combustion engines.

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정적 연소기에서 순간온도 프로브의 돌출높이에 따른 열유속에 관한 연구 (A Study of Heat Flux on the Height of an Instantaneous Temperature Probe in a Constant Volume Combustion Chamber)

  • 이치우
    • 열처리공학회지
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    • 제16권4호
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    • pp.216-223
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    • 2003
  • In the production of internal combustion engines, there have been trends to develop the high performance engines with improved fuel efficiency, lighter weights and smaller sizes. This trends help to answer problems related to thermal load and abnormal combustion, etc. in these engines. In order to investigate these problems, a thin film-type probe and its manufacturing method for instantaneously measuring surface-temperatures have been proposed in this study, Instantaneous surface temperature of a constant volume combustion chamber was measured by this probe and heat flux was obtained by Fourier analysis. In order to thoroughly understand the characteristics of combustion, the authors measured the wall temperature of the combustion chamber and computed heat flux through a cylinder wall while varying the protrusion height of the probe have been measured. To achieve the above goals, a instantaneous temperature probe was developed, thereby making possible the analysis of the instantaneous temperature of wall surface and the detection of unsteady heat flux in the constant volume combustion chamber.

연료 분무 및 연소 가시화 연구를 위한 고온 고압 정적 연소실 개발 (Development of High Pressure & Temperature Constant Volume Chamber for Visualization Study of Fuel Spray and Combustion)

  • 김기현
    • 동력기계공학회지
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    • 제21권3호
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    • pp.12-18
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    • 2017
  • Diesel and gasoline engines will be used as main power system of automobiles. Recently, engine downsizing is widely applied to both gasoline and diesel engines in order to improve fuel economy and exhaust emissions. Engine downsizing means small engine combustion chamber with higher combustion pressure. Therefore, spray and combustion process should be investigated under these high pressure and temperature conditions. In this study, constant volume combustion chamber which enables easy optical access from six directions was developed. Combustion chamber was designed to resist maximum pressure of 15 MPa and maximum temperature of 2,000 K. Combustible pre-mixed mixture was introduced into combustion chamber and ignited by spark plugs. High pressure and temperature were implemented by combustion of pre-mixed mixture. Three initial conditions of different pressure and density were tested. High repeatability of combustion process was implemented which was proven by low standard deviation of combustion pressure.

INFLUENCE OF INITIAL COMBUSTION IN SI ENGINE ON FOLLOWING COMBUSTION STAGE AND CYCLE-BY-CYCLE VARIATIONS IN COMBUSTION PROCESS

  • Lee, Kyung-Hwan;Kim, Kisung
    • International Journal of Automotive Technology
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    • 제2권1호
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    • pp.25-31
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    • 2001
  • It is necessary to understand the combustion process and cycle-by-cycle variation in combustion to improve the engine stability and consequently to improve the fuel economy and exhaust emissions. The pressure related parameters instead of mass fraction burned were compared for the effect of initial combustion pressures on the following combustion and the analysis of cycle-by-cycle variation in combustion for two pen injected SI engines. The correlation between IMEP and pressures at referenced crank angles showed almost the same trends for equivalence ratios, but the different mixture preparations indicated different tendency. The dependency of IMEP on pressure at the referenced crank angles increases as the mixture becomes leaner for both engines. The mixture distribution in the combustion chamber was varied with the coolant temperature and intake valve deactivation due to the evaporation of fuel and air motion. The correlation between pressure related parameters were also compared for the coolant temperatures and air motion.

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Structure and Formation of Diesel Fuel Spray

  • Fujimoto, Hajime;Dan, Tomohisa
    • 한국분무공학회지
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    • 제1권4호
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    • pp.8-20
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    • 1996
  • Research and development studies in internal combustion engines are set on a turning point due to requirements mostly purify the polluted environments. Naturally, basic studies concerned about engines are objected to elucidate formation mechanism of harmful matters, such as nitric oxide $(NO_x)$ and particulate matters. And for diesel engines, phenomenon in combustion chambers are analyzed in several approach ways in order to obtain detail understandings in closed and hardly observing space. In this article. it is discussed that the formation mechanism of diesel fuel sprays, mostly non-evaporating free diesel sprays. From that it would be promoted some new innovations in internal combustion engines of next generation.

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Analysis of Compression-induced Auto-ignition Combustion Characteristics of HCCI and ATAC Using the Same Engine

  • Iijima, Akira;Shoji, Hideo
    • Journal of Mechanical Science and Technology
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    • 제20권9호
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    • pp.1449-1458
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    • 2006
  • Controlled Auto-ignition (CAI) combustion processes can be broadly divided between a CAI process that is applied to four-cycle engines and a CAI process that is applied to two-cycle engines. The former process is generally referred to as Homogeneous Charge Compression Ignition (HCCI) combustion and the later process as Active Thermo-Atmosphere Combustion (ATAC) The region of stable engine operation differs greatly between these two processes, and it is thought that the elucidation of their differences and similarities could provide useful information for expanding the operation region of HCCI combustion. In this research, the same two-cycle engine was operated under both the ATAC and HCCI combustion processes to compare their respective combustion characteristics. The results indicated that the ignition timing was less likely to change in the ATAC process in relation to changes in the fuel octane number than it was in the HCCI combustion process.

쳔연가스 연료조성이 엔진 연소특성에 미치는 영향 (Effects of Natural Gas Composition on Combustion Characteristics in a Gas Engine)

  • 이중성;유현석;윤영석;한정옥
    • 한국자동차공학회논문집
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    • 제7권6호
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    • pp.32-41
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    • 1999
  • Natural gas is an attractive fuel in view of environment benefits due to its flow carbon-to-hydrogen ratio. However, its compositions and properties are varied depending upon production regional groups. Therefore, study on the combustion characteristics of natural gas engines with a variety of compositions has been demanded for the efficient application of gas engines. This study aims to investigate the effects of gas composition on engine combustion characteristics. It was found that , by controlling an engine with fixed fuel nozzle area, power and heat release were subject to Wobbe Index. And at fixed excess air ratios, power and heat release were subject to low heating value of unit mixture . In addition, in case of constant nozzle area, combustion duration was found to be inversely proportional to CP(Combustion Potential), and the condition of fixed excess air ratios showed no change in combustion duration, regardless of CP.

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압축착화 엔진에서 디젤-가솔린 Dual Fuel이 연소 및 배기 특성에 미치는 영향 (Fuel Injection System on Combustion and Exhaust Emissions Characteristics in Compression Ignition Engines)

  • 권석주;차준표;성기안;박성욱
    • 한국연소학회지
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    • 제16권1호
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    • pp.52-57
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    • 2011
  • The present study describes the characteristics of combustion and exhaust emissions in compression ignition engines using diesel-gasoline dual fuel. For investigating combustion characteristics, diesel fuel was injected directly in a single-cylinder compression ignition engine with a common-rail injection system and gasoline fuel was injected into a premixed chamber installed in an intake port. In order to investigate exhaust emission characteristics, exhaust gas was measured by emission analyzer and smoke meter. The experimental results showed that cases of diesel-gasoline dual fuel combustion exhibited extended ignition delay and reduced peak combustion pressure compared to those of directly injected diesel fuel cases. Furthermore, premixed gasoline-air mixture reduced NOx emissions due to low peak of rate of heat release(ROHR).

지연분사급속연소방식 예혼합연소 기술에 의한 NOx, PM의 동시저감 (Simultaneous NOx, PM Reduction by the Late Injection & Fast Combustion Type Premixed Combustion Technology)

  • 김장헌;최인용;김창일
    • 한국자동차공학회논문집
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    • 제12권4호
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    • pp.31-35
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    • 2004
  • A new combustion strategy called LIFC(Late Injection & Fast Combustion) was developed for simultaneous reduction of particulate matter(PM) and nitrogen oxides(NOx) in exhaust emission of diesel engines, In this study, effects of injection timing and injection pressure under relatively high EGR rate were investigated. The experiments were conducted in a conventional engine over a range of commercial engine speed. The test engine could be operated in LIFC up to 2000rpm / bmep 5 bar condition with significant reduction of NOx and PM. The experimental results showed potential for the mechanism of the simultaneous reduction of NOx and PM from HSDI diesel engines.