• Title/Summary/Keyword: Injection-rate

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A study on the spray characteristics of CRDI system with injection pressure (분사압력에 따른 CRDI 분사계의 분무특성에 관한 연구)

  • KIM, Sang-Am;WANG, Woo-Gyeong;YANG, Jung-Kyu
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.1
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    • pp.65-71
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    • 2016
  • Injection rate, injection quantity and injection timing of fuel are controlled precisely by electric control in CRDI system. Particularly, injection rate being influenced with injection pressure affects to spray characteristics and fuel-air ratio, so it is a very important factor in diesel combustion. In this study, injection rates in accordance with injection pressure at a constant ambient pressure were measured with Zeuch's method. Under the same condition, non-evaporating spray images were taken with a high speed camera and analyzed carefully with Adobe Photoshop CS3. Macroscopic spray characteristics and breakup processes in the spray could be found from the examined and analyzed data. Injection start time and injection period were practically affected with injection pressure. Also, initial injection rate, spray penetration, spray angle and breakup of high density droplets region in the spray were affected with injection pressure. The results and techniques of spray visualization and injection rate measurement in this study would be practically effective to study a high pressure diesel spray for common rail direct injection system.

A Study on the Characteristics of Injection-rate at Different Injection Conditions in a Common-rail Diesel Injector (분사조건에 따른 커먼레일 디젤 인젝터의 분사율 특성에 관한 연구)

  • Kim, H.M.;Chung, J.W.;Lee, K.H.
    • Journal of ILASS-Korea
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    • v.12 no.3
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    • pp.166-171
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    • 2007
  • Recently, many studies on HSDI diesel engines have been performed to reduce the fuel consumption and $CO_2$ emission. One of the prominent technique to reduce emission is a high pressure multiple injection. For this technique, the injection rate is a critical parameter in order to determine precise injection duration and timing for combustion control. Thus the purpose of this study was to investigate relationship between the injection rate and the time-signature of chamber pressure at different injection pressure conditions in a common rail direct injection type injector using the Zeuch method. Using the measured correlation constants, estimated fuel injection rates are presented at many different injection conditions.

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A Study on Injection Rate Characteristics of a Diesel Injector (디젤 인젝터의 분사율 특성에 관한 연구)

  • Chung, Jaewoo;Kim, Namho;Lim, Chanhyun;Kim, Dugjin
    • Journal of ILASS-Korea
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    • v.20 no.4
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    • pp.217-222
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    • 2015
  • In this study, Injection rate tests of a Diesel common-rail injector have been performed with injection volume measurement type injection rate test system EMI21 for construction of injector model can be used in an engine calibration mean valued model. The measuring principle of the test system is based on measurement of dispalcement of a movable measurement piston by the volume of fluid released by the injector. From these injection rate test results, the characteristics on shape of instantaneous injection rate and injection fuel amount have been investigated and injection fuel amount calculation equation based on test results has been newly constructed. This equation is very simple and calculation error is less than 5% with test results for wide range injection pressure (200~1800 bar) and injection duration ($200{\sim}1800{\mu}s$) conditions. So, it is anticipated that newly constructed simple injection fuel amount model in this study can be efficiently used on engine calibration and control model.

COMMON RAIL INJECTOR MODIFIED TO ACHIEVE A MODULATION OF THE INJECTION RATE

  • FICARELLA A.;GIUFFRIDA A.;LANZAFAME R.
    • International Journal of Automotive Technology
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    • v.6 no.4
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    • pp.305-314
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    • 2005
  • Injection rate shape control is one feature of a diesel fuel injection system that is strongly desired at this time. In the conventional common rail system, it is difficult to control the injection rate since the fuel pressure is constant during the injection period, resulting in a nearly rectangular rate shape. In order to look into possible injection modulations, injectors equipped with standard and geometrically modified control valves were investigated in detail by means of computer modelling and simulation. Experiments were carried out to validate the feasibility of such a shaping. The results of this study show a noteworthy dependence of the fuel rate on geometrical modifications in the piloting stage of the injector.

A study on the injection charateristics of the fuel injection system in a diesel engine (디젤기관 연료분사 시스템의 분사 특성에 관한 연구)

  • 이창식;김정헌
    • Journal of the korean Society of Automotive Engineers
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    • v.14 no.5
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    • pp.54-60
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    • 1992
  • This paper deals with the results of injection characteristics and the influence parameters upon the fuel injection performance of the inline injection system in a diesel engine. In this study, the characteristics of the injection rate, the injection pressure and the injection duration have been investigated by changing the injection parameters. The predicted results and injection performance are compared to the measured data from the injection test system.

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Dynamic Model of an HSDI Common-rail Injector and Injection Rate Estimation (HSDI 커먼레일 인젝터 동적 모델 및 분사율 추정)

  • 남기훈;박승범;선우명호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.43-49
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    • 2003
  • The common-rail fuel injection system is becoming a common technology for High Speed Direct Injection(HSDI) diesel engines. The injection timing and rate are important factors for combustion control and pollutants formation mechanisms during engine operation. This paper introduces an estimation methodology of the injection timing and rate of a common-rail injector for HSDI diesel engines. A sliding mode observer that is based on the nonlinear mathematical model of the common-rail injector is designed to overcome the model uncertainties. The injector model and the estimator we verified by relevant injection experiments in an injector test bench. The simulation and the experimental results show that the proposed sliding mode observer can effectively estimate the injection rate of the common-rail injector.

A Direct Injection-mixing Total-flow-control Boom Sprayer System (주입식 총유량 자동제어방식 분관 방제기의 개발)

  • 구영모
    • Journal of Biosystems Engineering
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    • v.21 no.2
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    • pp.155-166
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    • 1996
  • A direct injection sprayer was designed using the concepts of injection mixing and total flow control, flowrate-based system compensating for the variation of forwarding speed. A metered rate, proportionally to the actual diluent flow rate, of a tracer chemical was injected directly into the diluent stream. The injection of chemical may improve the precision and safety of chemical application process. The control system was evaluated for the variables of the control interval, tolerances and sensitivities of flow regulation valve and injection pump. Performance of the system was assessed as that the response time of flow rate, response time of injection rate, absolute steady state error, and the coefficient of variance(C.V.) of concentration were 8.5 and -0.53 seconds, 0.067 lpm(0.8%) and 3.15%, respectively, at optimal parameters of control interval of 1.0 sec, fast sensitivity of flow regulation valve, medium sensitivity of injection pump and medium tolerance of flow rate. Performance of the system can be improved by increasing the sensitivity of flow regulating valve and employing a high resolution velocimeter, such as Doppler radar.

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On the $NO_x$ in Direct Injection diesel engine (직접분사식 디이젤의$NO_x$에 관하여)

  • 안수길
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.12 no.1
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    • pp.1-6
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    • 1976
  • To investigate the relation of $NO_x$ emission and consumption rate in a direct injection diesel engine with a multihole nozzle under same fuel consumption and rpm, a naphthyl ethylenediaming method on NO, emission and Tektronix oscilloscop on the indicator diagrams have been used. Comparisons of the $NO_x$ emission and fuel consumption rate made on various conditions have led to the fllowing results. 1. The higher the injection pressure in the later injection time the lower $NO_x$ emission and the fuel consumption rate have been attained. 2. By the change of nozzle hole diameter under the same injection pressure, the $NO_x$ emission was much more lowered in the small diameter than large one, but fuel consumption rate was in inverse proption to the $NO_x$ emission. 3. The effect of injection spray angle, $\frac{1_n}{d_n}$ on $NO_x$ emission, fuel consumption rate under same injection time and injection pressure was neglectable.

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The Effects of Partially Premixed Pilot Injection Timing on the Combustion and Emission Characteristics in a Common Rail Diesel Engine (커먼레일식 디젤기관의 부분 예혼합 분사시기가 연소 및 배기특성에 미치는 영향)

  • Yoon, Sam-Ki;Choi, Nag-Jung
    • Journal of Power System Engineering
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    • v.17 no.6
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    • pp.18-24
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    • 2013
  • An experimental study was performed to investigate the characteristics of combustion pressure and exhaust emissions when the pilot injection timing and EGR rate were changed in a CRDI 4-cylinder diesel engine. The pilot injection timing and EGR rate have a significant impact on the combustion and emission characteristics of diesel engine. In this study, the pilot injection timing and EGR rate variation were conducted to 2000rpm of engine speed with torque 50Nm. Combustion pressure and heat release rate were decreased under high EGR rate conditions but increased under the pilot injection timing $20^{\circ}$(BTDC). IMEP and the maximum pressure in cylinder(Pmax) were decreased under the same injection timing with the increase of EGR rate. The NOx emission was decreased with increasing the EGR rate. On the other hand, in the same injection timing conditions, CO, HC, $CO_2$ emissions were increased with increasing the EGR rate.

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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