• Title/Summary/Keyword: injection pressure

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A Study on the Droplet Size Distribution of Ultra High Pressure Diesel Spray on Electronic Hydraulic Fuel Injection System (전자유압식 분사계에 의한 초고압 디젤분무의 입경분포에 관한 연구)

  • Jang, S.H.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.2 no.1
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    • pp.25-30
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    • 1998
  • In order to investigate the droplet size distribution and Sauter Mean Diameter in a ultra high pressure diesel spray, fuel was injected with ultra high pressure into the environments of high pressure and room temperature by an Electronic Hydraulic Fuel Injection System. Droplet size was measured with the immersion liquid sampling technique. The immersion liquid was used a mixture of water-methycellulose solution and ethanol. The Sauter Mean Diameter decreased with increasing injection pressure, with a decrease environmental pressure (back pressure) and nozzle diameter. Increasing the injection pressure makes the fuel density distribution of the spray more homogeneous. An empirical correlation was developed among injection pressure, air density, nozzle diameter and the Sauter Mean Diameter of spray droplets.

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An Experimental Study on Suitable Injection pressure in High Pressure Injection Region (초고압 디젤분무의 적정분사압력에 관한 실험적 연구)

  • Jeong, D.Y.;Kim, H.J.;Lee, Jong-T.
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.812-817
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    • 2001
  • Impinging spray characteristics were investigated to find suitable injection pressure by using high pressure injection system. Spray radius and spray height were increased continuously until 2,500bar but the rate of enhancement was decreased suddenly over this injection pressure region. It is expected that the maximum suitable injection pressure of impinging spray exists at around 2,500bar.

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A study on the effect of injection pressure and ambient pressure for the growth of impinging spray (충돌 분무의 성장에 미치는 분사압과 배압의 영향에 관한 연구)

  • Cha, Geon-Jong;Seo, Gyeong-Il;Kim, Deok-Jul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.11
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    • pp.1458-1465
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    • 1997
  • This study investigated the effects of pressure on the growth of an impinging spray. We obtained the frozen images which were scattered by Nd ; YAG laser light (pulse width : 7 ns) using synchronization circuit made in the laboratory. For an impinging spray a growth of the penetration length was progressed with increase of the injection pressure but an ambient pressure restrained its growth. The effect of an ambient pressure on penetration was larger than that of an injection pressure. The pressure ratio had an effect on the penetration growth rate. The thickness growth rate depended on both the injection pressure and the ambient pressure compositively. A lower injection pressure or a higher ambient pressure was required for spatial distribution of impinging spray.

A Study on Injection and Combustion of D.I. Diesel Engine with Electronic-hydraulic Fuel Injection System (전자유압식 분사계를 갖는 D.I. 디젤기관의 분사 및 연소에 관한 연구)

  • Kim, Hyun-Gu;Ra, Jin-Hong;Ahn, Soo-Kil
    • Journal of Fisheries and Marine Sciences Education
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    • v.9 no.1
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    • pp.83-97
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    • 1997
  • Diesel engine is widely used for ship and industry source of power because of its high thermal efficiency and reliability and durability. However it lead to air pollution due to exhaust gas, and it is important to develop diesel engine of lower air-pollution to decrease the hazardous exhaust gas emissions. As one of the ways, the study for practically using the high pressure of fuel injection and variable injection timing system is being processing. The high pressure injection, which is said to be an effective means for reducing both NOx and particulate emissions, and great improvements in combustion characteristics have been reported by many researchers. In this study, electronic-hydraulic fuel injection system and hydraulic fuel injector system have been applied to the D.I. test engine for high pressure injection and variable injection timing. The injection pressure and injection rate depending upon accumulator pressure were measured with strain gage and Bosch injection rate measuring system before fitting the system into test engine, and analyzed the characteristics of the injection system. The combustion characteristics with this injection system has been analyzed with data concerning heat release rate, pressure rising rate, ignition point, ignition delay and maximum pressure value.

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A Study on the Combustion Characteristic and Soot Distribution of a Common Rail Type D.I.Diesel Visualized Engine with Pilot Injection (커먼레일식 직분식 가시화 디젤엔진의 파일럿 분사 연소 및 Soot 분포 특성에 관한 연구)

  • Han, Yong-Taek;Lee, Jae-Yong;Lee, Ki-Hyung
    • Journal of the Korean Society of Combustion
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    • v.8 no.3
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    • pp.31-37
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    • 2003
  • The objective of this work is to investigate the effect of swirl, injection pressure and pilot injection on D.I.Diesel combustion by using a transparent engine system. The test engine is equipped with common rail injection system to obtain high pressure and to control injection timing and duration. In this study, the combustion analysis and steady flow test were conducted to estimate the heat release rate from in-cylinder pressure and pilot injection was investigated by using LII technique. As the results, high injection pressure was found to shorten ignition delay as well as enhance peak pressure and heat release rate was greatly affected by injection timing and pilot injection. In addition, the results showed that the period of soot formation corresponded to the diffusion flame.

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A Study on Spray Characteristics Analysis of Free Spray of Diesel Fuel with Ultra High Pressure (극초고압영역에서의 디젤연료의 자유분무특성에 관한 연구)

  • Jeong, D.Y.;Lee, J.T.;Hong, G.B.
    • Journal of ILASS-Korea
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    • v.7 no.4
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    • pp.16-22
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    • 2002
  • The characteristics of free spray with ultra injection pressure was analyzed to clear the limit pressure of diesel engine. To obtain final goal, ultra high pressure injection equipment was developed, spray patterns were visualized under various ultra injection pressures. Spray penetration and spray width, volume and entrained air mass were increased with the increase of injection pressure. Sauter mean diameter and injection durstion wert decreased. But over 3,000bar of ultra injection pressure region the rates of increase show almost similar and finally the reversed tendencies at 4,140bar.

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Numerical Analysis of the Effect of Injection Pressure Variation on Spray Characteristics (분사압력변화가 분무특성에 미치는 영향에 관한 수치적 고찰)

  • Park K.
    • Journal of computational fluids engineering
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    • v.2 no.2
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    • pp.89-96
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    • 1997
  • High injection pressure system has been developed as a measure to reduce harmful exhaust gases. In order to understand the effect of pressure on diesel spray injection process, wide range of high injection pressure was tested. The gas phase is modelled by the Eulerian continuum conservation equations of mass, momentum, energy and fuel vapour fraction. The liquid phase is modelled following the discrete droplet model approach in Lagrangian form. The droplet distributions, vapor fractions and gas flows are analyzed in various injection pressure cases. The distributions of spray and vapor increase and the Sauter mean diameter decreases with increasing injection pressure quickly in a low pressure area but slowly in a high pressure area.

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A Study on Spray Characteristics of Diesel-Water Emulsion with Ultra High Pressure (초고압 경유-물 혼합연료의 분무특성에 관한 연구)

  • Jeong, D.Y.;Lee, J.T.
    • Journal of ILASS-Korea
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    • v.8 no.1
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    • pp.29-36
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    • 2003
  • Spray characteristics on diesel- water emulsion are analyzed in high pressure injection for several variables such as water content, injection pressure. Spray Patterns were visualized under various water content and injection pressures. Spray tip penetration was increased and spray angle decreased in accordance with increasing of water content. But these characteristics were enhanced with increase of injection pressure to high pressure.

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Effect of High Injection Pressure and Ambient Pressure on the DME Spray Characteristics Injected Through a Common-rail Diesel Injector (커먼레일 디젤 인젝터에서 연료 분사 및 분위기 압력이 DME 분무 특성에 미치는 영향)

  • Kim, Hyung-Jun;Park, Su-Han;Lee, Chang-Sik
    • Journal of ILASS-Korea
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    • v.14 no.2
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    • pp.71-76
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    • 2009
  • The aim of this investigation is to study the effect of the high injection pressure on the dimethyl ether (DME) spray characteristics injected through a common-rail diesel injector under various ambient pressures. In order to investigate the effect of the injection pressure and ambient condition, the common-rail injection system with two high pressure pumps and high pressure chamber pressurized up to 40 bar were used, respectively. Spray images of DME fuel obtained from a visualization system composed of high speed camera and two metal halide lamps as the light source. From the obtained images, the spray behaviors such as a spray development process, spray tip penetration, spray width, and spray cone angle were measured for analyzing the DME spray characteristics under various experimental conditions. It was found that the spray development slowed as the ambient pressure increased and spray tip penetration at injection pressure of 90 MPa is longer than that at 50 MPa. In addition, the spray width at the end stage of injection decreased under the atmospheric conditions due to the evaporation property of DME fuel, and DME spray shows narrow spray cone angle according to the injection pressure increased.

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Effects of Injection Pressures on Combustion and Emissions in a Direct Injection LPG Spark Ignition Engine (적접분사식 LPG엔진에서 연료분사압력이 연소/배기특성에 미치는 영향 연구)

  • Lee, Seok-Whan;Cho, Jun-Ho;Oh, Seung-Mook
    • Journal of ILASS-Korea
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    • v.16 no.1
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    • pp.7-14
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    • 2011
  • High pressure LPG fuel spray with a conventional swirl injector was visualized and the impact of the injection pressure was also investigated using a DISI (direct injection spark ignition) LPG single cylinder engine. Engine performance and emission characteristics were evaluated over three different injection pressure and engine loads at an engine speed of 1500 rpm. The fuel spray pattern appeared to notably have longer penetration length and narrower spray angle than those of gasoline due to its lower angular momentum and rapid vaporization. Fuel injection pressure did not affect combustion behaviors but for high injection pressure and low load condition ($P_{inj}$=120 bar and 2 bar IMEP), which was expected weak flow field configuration and low pressure inside the cylinder. In terms of nano particle formation the positions of peak values in particle size distributions were not also changed regardless of the injection pressure, and its number densities were dramatically reduced compared to those of gasoline.