• 제목/요약/키워드: Diesel Injector

검색결과 193건 처리시간 0.023초

고압 디젤 인젝터 노즐 홀 수가 연료 분무 및 배기 특성에 미치는 영향 (Effect of Nozzle Hole Number on Fuel Spray and Emission Characteristics of High Pressure Diesel Injector)

  • 전문수
    • 한국분무공학회지
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    • 제17권4호
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    • pp.210-215
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    • 2012
  • This paper This paper presents effect of nozzle hole number on spray characteristics and engine performance. Experiments were conducted to measure spray penetration and SMD distributions using a spray visualization system and PDPA (phase Doppler particle analyzer) system. In addition, engine performance and emission characteristics were measured using a single cylinder engine and emssion measurement systems. Results showed that 8-hole-injector exhibits improved spray performances. Furthermore, soot emission was decreased with 8-hole-injector, compared to that of 6-hole-injector.

인젝터 노즐 형상이 노즐 내부 유동 및 출구 특성에 미치는 영향 (Influences of Injector Nozzle Shape on Nozzle Internal Flow and Outlet Characteristics)

  • 김창현;이강수;박재인;백제현
    • 한국자동차공학회논문집
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    • 제21권6호
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    • pp.108-116
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    • 2013
  • Diesel engine injector is used for spraying the fuel into the cylinder chamber. Complex phenomenon like cavitation occurs from small scale domain, highly pressurized condition and rapid injection. Flow inside the nozzle affects the whole engine performance including combustion and exhaust, therefore understanding the flow inside the injector nozzle is very important. In this paper, cylindrical and convergent-divergent nozzles are suggested for nozzle types and their influences on nozzle internal flow and nozzle outlet characteristics will be analyzed by changing their outlet diameters.

커먼레일식 디젤 인젝터의 충돌 분무에 대한 실험적 연구(1) -거시적 분무 발달 과정- (An experimental study on the impingement spray of a common-rail diesel injector (1) -macroscopic characteristics-)

  • 이창식;박성욱;서상헌
    • 한국분무공학회지
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    • 제8권3호
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    • pp.10-18
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    • 2003
  • In this paper, experimental study on the wan impingement spray of the common-rail diesel injector is performed. To examine the effect of various factors on the development of spray impinging on the wall, experiments were conducted at the various injection pressures. ambient pressures, wan distances from the injector tip, wall temperatures, and angles of wall inclination. The behaviors of the impingement spray ate visualized by using laser sheet methods and a ICCD camera. It is shown that the spray path penetration of the wall impingement spray increases with the increase of injection pressure, wall distance. wall temperature, wall angle. On the other hand the spray path penetration of the wan impingement spray decreases with the increase of ambient pressure.

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작동 연료온도가 Bypass type 피에조 인젝터의 분사 특성에 미치는 영향 (Effects of Working Fuel Temperature on Injection Characteristics of Bypass Type Piezo Injector)

  • 조인수;이진욱
    • 한국분무공학회지
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    • 제24권2호
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    • pp.66-72
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    • 2019
  • Diesel vehicles suffer from poor starting and running problems at cold temperatures. Diesel vehicles have the characteristic that CO and PM are reduced or similarly discharged when going from low temperature to high temperature. In this study, a bypass type piezo injector for electronic control based common rail injection system was used. Numerical analysis using injector drive analysis model was performed to analyze injector drive and internal fuel flow characteristics according to fuel temperature change. The results show that the rate of density change due to the fuel temperature is proportional, and that the effect of the kinematic viscosity is relatively large between $-20^{\circ}C$ and $0^{\circ}C$. Comparing the results of temperature condition at $0^{\circ}C$ and $20^{\circ}C$, it is considered that the viscosity is more correlated with the needle displacement than the pressure chamber of the delivery chamber.

Dimethyl Ether와 디젤의 거시적 분무 특성 비교 (Comparison of Macroscopic Spray Characteristics of Dimethyl Ether with Diesel)

  • 유준;이주광;배충식
    • 한국자동차공학회논문집
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    • 제10권5호
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    • pp.73-80
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    • 2002
  • Dimethyl ether (DM) is one of the most attractive alternative fuel far compression ignition engine. Its main advantage in diesel engine application is high efficiency of diesel cycle with soot free combustion though conventional fuel injection system has to be modified due to the intrinsic properties of DME. Experimental study of DME and conventional diesel spray employing a common-rail type fuel injection system with a 5-holes sac type injector (hole diameter 0.168 ㎜/hole) was performed in a high pressure chamber pressurized with nitrogen gas. A CCD camera was employed to capture time series of spray images followed by spray cone angles and penetrations of DME were characterized and compared with those of diesel. Under atmospheric pressure condition, regardless of injection pressure, spray cone angles of the DME were wider than those of diesel and penetrations were shorter due to flash boiling effect. Tip of the DME spray was farmed in mushroom like shape at atmospheric chamber pressure but it was disappeared in higher chamber pressure. On the contrary, spray characteristics of the DME became similar to that of diesel under 3MPa of chamber pressure. Hole-to-hole variation of the DME spray was lower than that of diesel in both atmospheric and 3MPa chamber pressures. At 25MPa and 40MPa of DME injection pressures, regardless of chamber pressure, intermittent DME spray was observed. It was thought that vapor lock inside the injector was generated under the two injection pressures.

전자제어 디젤엔진의 흡기 다기관 및 연료분사장치 정비에 따른 매연 배출특성에 관한 연구 (Study on the Characteristics of Exhaust Emissions in accordance with the Intake Manifold and Fuel Injector Maintenance of the Electronic Control Diesel Engine)

  • 강현준;김태중
    • 한국산학기술학회논문지
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    • 제17권9호
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    • pp.196-205
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    • 2016
  • 자동차로부터 배출되는 배기가스는 오존 및 미세먼지 등의 농도를 증가시켜 인체의 건강을 위협할 뿐만 아니라 지구 온난화 물질인 이산화탄소를 다량 배출하고 있어 지구 온난화에도 지대한 영향을 미치고 있다. 그래서 정부는 자동차에서 배출되는 배기가스를 효율적으로 규제하기 위한 제도로 운행차 배출가스 정밀검사 제도를 시행하고 있다. 자동차 배출가스를 줄이려는 연구는 다방면으로 이루어지고 있으며, 자동차의 배출가스 중 HC, NOx, $CO_2$ 등의 발생을 줄이기 위한 연구가 이루어지고 있다. 그러나 노후된 자동차에 대한 배출가스 저감에 대한 연구는 부족한 실정이다. 노후된 디젤자동차들이 운행차 배출가스 정밀검사를 만족하기 위해서는 흡기 다기관(manifold)과 인젝터의 카본퇴적물(Carbon sediment)을 세척하여 출력향상 및 배출가스 저감에 대한 연구가 필요하다. 따라서 본 연구에서는 차령 5년 이상, 주행거리 80,000 km 이상의 디젤자동차에 흡기 다기관 클리닝과 인젝터 클리닝을 동시에 수행하여 매연 발생에 미치는 영향을 비교 분석하였다. 실험결과, 흡기다기관 클리닝과 인젝터 클리닝을 동시 수행한 결과는 각각 수행한 결과보다 매연을 75.2% 감소시켰다. 또한, 흡기다기관 클리닝과 인젝터 클리닝을 동시 수행한 결과는 검사 후 8.5초부터 배출허용 기준 30%이하를 만족하였다.

커먼레일 디젤 엔진용 피에조 인젝터 제어에 관한 연구 (A Study on the Piezo Injector Control Algorithm for CRDI Diesel Engines)

  • 오병걸;오승석;박영섭;이강윤;선우명호
    • 한국정밀공학회지
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    • 제26권2호
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    • pp.54-62
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    • 2009
  • The purpose of this study is to develop a piezo injector driver for common-rail direct injection diesel engines. In this research, we analyzed the electrical and mechanical characteristics of the piezo actuator through experiments. Current flow and charging voltage of the piezo injector are controlled by the PWM signal of variable duty ratio in order to realize both fast response and low peak current. The optimal switching duty ratio was designed by modeling and analyzing of the piezo driver circuit. In order to avoid resonance and unacceptably long settling time, appropriate frequency range of the PWM signal was derived based on the driver circuit model. The developed injector driver was validated by experiments under various fuel rail pressure, injection duration, and charging voltage.

상용차 디젤의 연료분사장치 유닛 인젝터 핵심부품인 스필 밸브의 성능 복원 관한 연구 (A Study on Restoration Technology of Unit Injector Spill Valve for Injection System of Commercial Diesel Engine)

  • 이충근;이정호;이대엽
    • 한국자동차공학회논문집
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    • 제25권3호
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    • pp.389-396
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    • 2017
  • Restorations of automotive parts have been done ever since the first vehicle was produced. Because the most expensive parts of a vehicle are in the engine system, there have been various restoration methods developed for engine parts. In the case of commercial diesel engines, the fuel injection device is a key and expensive component. It also has a significant effect on vehicle performance. In particular, reduced engine power and increased exhaust gas emissions may result from mechanical damage due to abrasion of the spill valve in the fuel injection system of a diesel engine. In this paper, restoration techniques for damaged parts are applied to restore the abrasion of a spill valve of fuel injection, also called as the "unit injector", of commercial diesel engines. In order to recover the damage, optimized polishing techniques using hard-metal and coating processes are applied. To evaluate restoration techniques for the spill valve, performance and durability tests are performed on a test bench.

AMESim기반 피에조 인젝터용 해석모델의 민감도 특성 해석 (Analysis of Sensitivity Characteristics with AMESim Model for Piezo Injector)

  • 조인수;권지원;이진욱
    • 한국자동차공학회논문집
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    • 제21권2호
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    • pp.17-25
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    • 2013
  • Performance of DI diesel engine with high fuel injection method is directly related to the emission characteristics and fuel consumption. At present, diesel injection system with piezo element is replacing conventional solenoid type due to their faster electro-mechanical properties. In this study, it was investigated the sensitivity characteristics regarding internal hydraulic modeling based on the AMESim environment of piezo-driven injector The analytic parameter for this study defined such as In/Out orifice, injection hole's diameter and driven voltage on piezo stack. As the results, it was shown that these parameter influence on a fast response characteristics of piezo-driven injector. Also we found fuel pressure recovery time is faster about 0.1 ms due to larger IN orifice diameter. And larger OUT orifice diameter occurs maximum pressure drop with faster its timing of about 0.2 ms.

고압 인젝터의 분사율 예측을 위한 경량 모델 개발 (Development of a Lightweight Prediction Model of Fuel Injection Rates from High Pressure Fuel Injectors)

  • 이상권;배규한;;문석수;강진석
    • 한국분무공학회지
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    • 제25권4호
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    • pp.188-195
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    • 2020
  • To meet stringent emission regulations of automotive engines, fuel injection control techniques have advanced based on reliable and fast computing prediction models. This study aims to develop a reliable lightweight prediction model of fuel injection rates using a small number of input parameters and based on simple fluid dynamic theories. The prediction model uses the geometry of the injector nozzle, needle motion data, injection conditions and the fuel properties. A commercial diesel injector and US No. 2 diesel were used as the test injector and fuel, respectively. The needle motion data were measured using X-ray phase-contrast imaging technique under various fuel injection pressures and injection pulse durations. The actual injector rate profiles were measured using an injection rate meter for the validation of the model prediction results. In the case of long injection durations with the steady-state operation, the model prediction results showed over 99 % consistency with the measurement results. However, in the case of short injection cases with the transient operation, the prediction model overestimated the injection rate that needs to be further improved.