• Title, Summary, Keyword: Fuel pressure control

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Study on Performance of an Fuel Pressure Regulator under Failure Condition in an Electric Control Diesel Engine (전자제어 디젤엔진의 연료압력 레귤레이터 고장에 따른 진단 및 성능 연구)

  • Kim, Tae-Jung;Cho, Hong-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.1677-1683
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    • 2015
  • To cope with exhaust gas regulation, Diesel engine applied to electronic control system. As it accurately regulated the injected fuel mass and the fuel efficiency and the output are increased but the noise and the vibration are decreased. In order to keep the performance of Electronic Diesel Control System, it is important to accurately control the fuel pressure. However, when the regulator of fuel pressure is not controlled properly, the failure phenomenons(starting failure, staring delay, accelerated failure, engine mismatch et al.) occur because the fuel pressure is not stabilize. In this study, effects on a fuel pressure, engine rotating speed according to the control rate of fuel-pressure regulator are investigated in order to analyzed the performance variation with failure of fuel-pressure regulator. As a result, when the control rate of a fuel-pressure regulator is 4%~6% lower than that of standard condition, the variation of engine's rpm and return fuel flow is increased, and the abnormal condition was occurred. Besides, it is possible to diagnose the failures on fuel-pressure regulator under these conditions.

Sensorless Starting Method and Fuel Pressure Control of BLDC Motor for Fuel Pump of Vehicle (자동차 연료 펌프용 BLDC 모터의 센서리스 기동 및 연료 압력 제어)

  • Chang, Jin-Wook;Yoon, Duck-Yong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.2
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    • pp.114-121
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    • 2013
  • High efficiency operation is required for motors of vehicle to increase fuel efficiency due to the regulation of exhaust gas. This paper presents a control method of fuel pressure to increase fuel efficiency and a sensorless control method of BLDC motor to get higher efficiency than conventional brushed DC motor. Initial rotor position of BLDC motor is detected from current value that is occurred by test voltage pulse and rotor is accelerated by defined sequence to enter sensorless operation mode. The algorithm to control flow rate of fuel pump uses PI controller that is control motor speed to maintain the target fuel pressure commanded by ECU.

Study of the effects of injector cleaning on the exhaust gases in a common rail diesel engine (커먼레일 디젤엔진의 인젝터 클리닝이 배기가스에 미치는 영향에 관한 연구)

  • Cho, Hong-Hyun;Kim, Tae-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.10
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    • pp.5980-5987
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    • 2014
  • As a response to exhaust gas regulations, the electronic control system was applied to the diesel engine. The injected fuel mass and injection timing are accurately controlled using it, and the fuel efficiency and the engine output are significantly increased. In addition, the noise and the vibration of vehicles are decreased. To maintain the optimal performance of an electronic control diesel engine, it is important to control the fuel injection pressure accurately using the fuel pressure regulator. When the fuel pressure regulator is not worked normally, the failure phenomena (starting failure, staring delay, accelerated failure, engine mismatch et al.) occurred because the fuel pressure is not stabilized and controlled accurately. In this study, the effects on a fuel pressure, return fuel mass flow, and engine rotating speed according to the control rate of fuel pressure regulator were investigated to analyze the performance variation under the failure conditions of a fuel pressure regulator. As a result, when the control rate of a fuel pressure regulator decreased by 4%~6% compared to that of the standard condition, the variation of engine rotating speed and return fuel flow were increased greatly, and the abnormal condition occurred. In addition, it is possible to diagnose the failure of a fuel pressure regulator by monitoring these conditions.

A Control Strategy of Fuel Injection Quantity and Common-rail Pressure to Reduce Particulate Matter Emissions in a Transient State of Diesel Engines (승용디젤엔진의 과도구간 입자상물질 저감 및 운전성능 향상을 위한 연료분사량 및 커먼레일압력 제어전략)

  • Hong, Seungwoo;Jung, Donghyuk;Sunwoo, Myoungho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.6
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    • pp.623-632
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    • 2015
  • This study proposes a control strategy of the common rail pressure with a fuel injection limitation algorithm to reduce particulate matter (PM) emissions under transient states. The proposed control strategy consists of two parts: injection quantity limitation and rail pressure adaptation. The injection limitation algorithm determines the maximum allowable fuel injection quantity to avoid rich combustion under transient states. The fuel injection quantity is limited by predicting the burned gas rate after combustion; however, the reduced injection quantity leads to deterioration of engine torque. The common rail pressure adaptation strategy is designed to compensate for the reduced engine torque. An increase of the rail pressure under transient states contributes to enhancement of the engine torque as well as reduction of PM emissions by promoting atomization of the injected fuel. The proposed control strategy is validated through engine experiments. The rail pressure adaptation reduced the PM emission by 5-10% and enhanced the engine torque up to 2.5%.

Injector Control Logic for a Liquid Phase LPG Injection Engine (액상 LPG 분사 엔진의 인젝터 제어 로직)

  • 조성우;민경덕
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.15-21
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    • 2003
  • The liquid phase LPG injection engine is a new technology to make good use of LPG as a clean energy. However, it is difficult to precisely control air/fuel ratio in the system because of variation of fuel composition, change of temperature and flash boiling injection mechanism. This study newly suggests an injector control logic for liquid phase LPG injection systems. This logic compensates a number of effects such as variations of density, stoichiometric air/fuel ratio, injection delay time, injection pressure, release pressure which is formed by flash boiling of fuel at nozzle exit. This logic can precisely control air/fuel ratio with only two parameters of intake air flow rate and injection pressure without considering fuel composition, fuel temperature.

Observer Based Nonlinear State Feedback Control of PEM Fuel Cell Systems

  • Kim, Eung-Seok
    • Journal of Electrical Engineering and Technology
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    • v.7 no.6
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    • pp.891-897
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    • 2012
  • In this paper, the observer based nonlinear state feedback controller has been developed to control the pressures of the oxygen and the hydrogen in the PEM(Proton Exchange Membrane) fuel cell system. Nonlinear model of the PEM fuel cell system was introduced to study the design problems of the state observer and model based controller. A cascade observer using the filtering technique was used to estimate the pressure derivatives of the cathode and the anode in the system. In order to estimate the pressures of the cathode and the anode, the sliding mode observer was designed by using these pressure derivatives. To estimate the oxygen pressure and the hydrogen pressure in the system, the nonlinear state observer was designed by using the cathode pressure estimates and the anode it. These results will be very useful to design the state feedback controller. The validity of the proposed observers and the controller has been investigated by using the Lyapunov's stability analysis strategy.

Various Injection Conditions and Fuel Control of an LPG Liquid Injection Engine (다양한 분사조건과 LPG 액상분사엔진의 연료량 제어)

  • Sim Hansub
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.1
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    • pp.28-35
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    • 2005
  • Fuel injection rate of an injector is affected by various injection conditions such as injection duration, fuel temperature, injection pressure, and voltage in LPG liquid injection systems for either a port-fuel-injection(PFI) or a direct injection(DI) in a cylinder. Even fuel injection conditions are changed, the air-fuel ratio should be accurately controlled to educe exhaust emissions. In this study, correction factor for the fuel injection rate of an injector is derived from the density ratio and the pressure difference ratio. A voltage correction factor is researched from injection test results on an LPG liquid injection engine. A compensation method of the fuel injection rate is proposed for a fuel injection control system. The experimental results for the LPG liquid injection system in a SI-engine show that this system works well on experimental range of engine speed and load conditions. And the fuel injection rate is accurately controlled by the proposed compensation method.

A Study on the Performance Characteristic of Common Rail High Pressure Pump (커먼레일 시스템용 고압펌프의 성능 특성에 관한 연구)

  • Lee, Choon-Tae
    • Journal of Power System Engineering
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    • v.17 no.6
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    • pp.5-10
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    • 2013
  • Diesel engines have the advantages of good fuel efficiency and low emissions. Therefore, car makers have been developed various kinds of diesel engine management system to clean up emissions while improving fuel efficiency. One of them is the common rail system. In the common rail system, diesel fuel is injected into the combustion chamber at ultra high pressures up to 1,800 bar to ensure more complete combustion for cleaner exhaust gas, and highly precise multiple injection reduces NOx emission, combustion noise and vibration. Generally speaking, common rail system consists of booster pump, high pressure pump, common rail, injectors, control valves, and sensors. The high pressure pump receives low pressure fuel from the booster pump and supply high pressure fuel to injectors through the high pressure common injection rail. Therefore, high pressure pump has an important role in common rail system. In this paper, we have investigated the performance of high pressure pump of common rail system.

Hydraulic Modal Analysis of High-Pressure Common-rail Fuel Injection System for Passenger Vehicle (승용 CR 연료분사시스템에 대한 유압 Modal 분석)

  • Sung, Gisu;Kim, Sangmyeong;Kim, Jinsu;Lee, Jinwook
    • Journal of ILASS-Korea
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    • v.20 no.1
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    • pp.14-19
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    • 2015
  • Recently, R&D demand for environmental friendly vehicle has rapidly increased due to its global environmental issues such as global warming, energy and economic crisis. Under this situation, the most realistic alternative way for environmental friendly vehicle is a clean diesel vehicle. The common-rail fuel injection system, as key technology of clean diesel vehicle, consists of a high pressure pump, common-rail, high pressure fuel line and electronic control injector. In common-rail high-pressure fuel injection system, high pressure wave of injection system and geometry of injector elements have a major effects on high-pressure fuel spray. Therefore, in this study, the numerical model was developed for analysis about the common-rail fuel pressure pulsation by using AMESim code. We could secure stability of common-rail high-pressure fuel injection system through optimal design of fuel line.

Transient Flow Behavior of Propellant with Actuation of Thrust Control Valve in Satellite Propulsion System (위성 추진시스템의 추력제어밸브 작동에 따른 추진제 비정상 유동 특성)

  • Kim, Jeong-Soo;Han, Cho-Young;Choi, Jin-Chul
    • Proceedings of the KSME Conference
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    • pp.294-298
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    • 2001
  • Satellite propulsion system is employed for orbit transfer, orbit correction, and attitude control. The monopropellant feeding system in the low-earth-orbit satellite blowdowns fuel to the thrust chamber. The thrust produced by the thruster depends on fuel amount flowed into the combustion chamber. If the thruster valve be given on-off signal from on-board commander in the satellite, valve will be opened or closed. When the thrusters fire fuel flows through opened thruster valve. Instantaneous stoppage of flow in according to valve actuation produces transient pressure due to pressure wave. This paper describes transient pressure predictions of the KOMPSAT2 propulsion system resulting from latching valve and thrust control valve operations. The time-dependent set of the fluid mass and momentum equations are calculated by Method of Characteristics (MOC).

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