• Title/Summary/Keyword: Fuel pressure control

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Estimation of Inlet Air Mass Flow for Air-Fuel Raito Control of Gaseous-Fuel Engines (기체연료 엔진에서 공연비제어를 위한 흡입공기량 추정)

  • 심한섭;이강윤;선우명호;송창섭
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.5
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    • pp.131-139
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    • 2001
  • Highly accurate control of the air-fuel ratio is important to reduce exhaust gas emissions of the gaseous-fuel engines. In order to achieve this purpose, inlet air mass flow must be measured exactly, and precise engine models are necessary to design engine control systems. In this paper, the effects of water vapor and gaseous fuel that change the air mass flow are studied. The effective air mass ratio is defined as the air mass flow divided by the mixture mass flow, and also it is applied to the estimation of the inlet air mass flow. The presence of the gaseous fuel and the water vapor in the mixture reduces the air partial pressure and the effective air mass ratio of the gaseous-fuel engines. The Experimental results for an LPG engine show that the estimation of the inlet ai mass flow based upon the effective air mass ratio is more accurate than that of the normal air mass flow.

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Modeling, simulation and control strategy for the fuel cell process (모델링 및 전산모사를 통한 연료전지공정의 제어전략에 관한 연구)

  • 이상범;이익형;윤인섭
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1012-1015
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    • 1996
  • This study focuses on the optimal operation and control strategy of the fuel cell process. The control objective of the Phosphoric Acid Fuel Cell (PAFC) is established and dynamic modeling equations of the entire fuel cell process are formulated as discrete-time type. On-line optimal control of the MIMO system employs the direct decomposition-coordination method. The objective function is modified as the tracking form to enhance the response capability to the load change. The weight factor matrices Q,R, which are design parameters, are readjusted. This control system is compared with LQI method and the results show that the suggested method is better than the traditional method in pressure difference control.

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Construction of Map for Transient Condition of a Sl Engine and Refinement of Intake Air Model & Fuel Model (가솔린 엔진의 비정상 상태에 대한 Map 구성과 공기 및 연료 모델 개선)

  • 심연섭;강태성;강승표;고상근
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.5
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    • pp.1-8
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    • 2002
  • For gasoline engines, a three-way catalytic converter that has the maximum efficiency at stoichiometric air/fuel ratio is used to clean up the exhaust gas. So a precise air/fuel ratio control is necessary to maximize the catalytic conversion efficiency, For a transient condition, a fred-forward air/fuel ratio control method that estimates the air mass inducted into a cylinder is being used. In this study, a fuel injection map that makes an accurate air/fuel ratio control possible was constructed for the very same transient condition. For the same condition above, intake air model and fuel model were refined so that fuel injection values based on air mass through a throttle valve and intake manifold pressure are equal to the map values.

A Study on the Controller Design for PEM Fuel Cell Systems (고분자연료전지 발전시스템의 제어기설계에 관한 연구)

  • Kim, Enug-Seok;Kim, Cherl-Jin
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1132_1133
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    • 2009
  • In this paper, a observer-based PI controller will be developed for PEM fuel cell system. Nonlinear model of PEM fuel cell system is introduced to study the controller design problems. Sliding mode observer will be designed to estimate the cathode and anode pressures of PEMFC system. And a nonlinear state observer is also designed to estimate the other states such as supply manifold pressure, Oxygen pressure, Hydrogen pressure, return manifold pressure, etc. These estimated states are used to design the observer-based PI controller. The validity of the proposed controller will be verified by using computer simulation.

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The Effect of Split Injections on the Stability of Idle Combustion and Emissions Characteristic in a Gasoline Direct Injection Engine (GDI 엔진의 분할 분사가 아이들 연소 안정 및 배출물 특성에 미치는 영향)

  • Roh, H.G.
    • Journal of ILASS-Korea
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    • v.19 no.4
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    • pp.221-226
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    • 2014
  • This paper described the effect of split injections on the stability of combustion and emission characteristics in a direct injection gasoline engine at various operating conditions. In order to investigate the influence of direct injection gasoline engine, the fuel injection timing was varied direct fuel injection at various fuel pressure. The experimental apparatus consisted of GDI engine with 4 cylinder, EC dynamometer, injection control system, and exhaust emissions analyzer. The emission and combustion characteristics were analyzed for the fuel injection timing and fuel injection pressure strategies. It is revealed that CO and HC emissions are dramatically decreased at advanced injection timing. Also, engine performance is increased at increase fuel injection pressure.

A Study on the Combustion Characteristics according to Evaporation rate of Methanol - Blended Fuel (메탄올 혼합 연료의 기화율 변화에 따른 연소특성에 관한 실험적 연구)

  • Cho, H.M.
    • Journal of ILASS-Korea
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    • v.2 no.2
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    • pp.24-34
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    • 1997
  • This paper describes the investigation of combustion characteristics of gasoline-methanol blend in constant volume combustion chamber. A constant volume combustion chamber was used to elucidate a basic combustion characteristics and the premixer was installed to control temperature and equivalence ratio. And the maximum pressure, combustion duration and flame propagation according to the evaporation rate were measured to determine the optimal temperature range for evaporating a blend fuel. These experimental results indicate that the combustion characteristics such as combustion chamber pressure and combustion were deteriorated by decreasing surrounding temperature of fuel. These experimental results indicate that the combustion characteristics such as combustion chamber pressure and combustion were deter orated by decreasing surrounding temperature of fuel injected. It was also found that the overall gasification process for methanol blend fuel was influenced by a combustion chamber temperature rather than a premixer temperature.

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A Study on the Behavior Characteristics of Diesel Spray by Using a High Pressure Injection System with Common Rail Apparatus

  • Yeom, Jeong-Kuk;Hajime Fujimoto
    • Journal of Mechanical Science and Technology
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    • v.17 no.9
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    • pp.1371-1379
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    • 2003
  • The effects of change in injection pressure on spray structure in high temperature and pressure field have been investigated. The analysis of liquid and vapor phases of injected fuel is important for emissions control of diesel engines. Therefore, this work examines the evaporating spray structure using a constant volume vessel. The injection pressure is selected as the experimental parameter, is changed from 22 MPa to 112 MPa using a high pressure injection system (ECD-U2). Also, we conducted simulation study by modified KIVA-II code. The results of simulation study are compared with experimental results. The images of liquid and vapor phase for free spray were simultaneously taken by exciplex fluorescence method. As experimental results, the vapor concentration of injected fuel is leaner due to the increase of atomization in the case of the high injection pressure than in that of the low injection pressure. The calculated results obtained by modified KIVA-II code show good agreements with experimental results.

Fuel Cell Modeling and Load Controlling by the Variable Utilization of Airflow (연료전지 모델링 및 공기이용률 제어에 관한 연구)

  • Song, S.H.;Lee, W.Y.;Kim, C.H.;Park, Y.P.
    • Journal of the Korean Electrochemical Society
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    • v.6 no.1
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    • pp.48-52
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    • 2003
  • A mathematical dynamic model of fuel cell was formulated in order to design the control system which will meet the control object. The control objective is set to regulate the airflow in the load change by utilization of airflow and the pressure difference between anode and cathode is maintained below a limit range. Simulation result of 10kW polymer electrolyte membrane fuel cell (PEMFC) clearly demonstrates that response time need to be less. than 1 seconds for the control requirements. Besides, pressure difference was allowed in pressure range less than 0.01 atm.

Design of Multi Step Fuel Pump Controller for Vehicle's Fuel Retrenchment (자동차 연료 절감을 위한 연료펌프 다단 제어기 설계)

  • Yang, Jae-Won;Yang, Seung-Hyun;Lee, Suk-Won
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.307-308
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    • 2007
  • At present, there are unnecessary electrical consumes and a lot of fuel-losses by the vaporized gas due to the rising of fuel temperature because the fuel pump of the fuel supply system rotates regularly regardless to the driving condition. In this paper, we designed the multi-step controller for controlling fuel pump to supply fuel according to RPM of each moment by measuring the real time RPM of the engine at ECU of the vehicle. Also, it can judge the existence or nonexistence of disorder by measuring the pressure of the fuel supply line, in case of abnormal state, it can supply the fuel intelligently by changing the mode to self-compensation mode.

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A numerical analysis of the delivery pressure wave in a 210-kW/cyl fuel injection pump for medium-speed diesel engines (210 kW/cyl 급 중속디젤엔진의 연료분사펌프 송출 압력파에 관한 수치 해석)

  • Kong, Kyeong-Ju;Jung, Suk-Ho;Lee, Sang-Deuk;Koh, Dae-Kwon
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.4
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    • pp.295-300
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    • 2016
  • This paper presents a numerical analysis of the delivery pressure wave in a 210-kW/cyl fuel injection pump (P. Corporation, Changwon-si, Korea) for medium-speed diesel engines using Ansys Fluent R15.0. Results obtained from experiment and from numerical analysis of the fuel delivery pressure wave were compared and found to be similar, thereby confirming the reliability of the numerical analysis of the delivery pressure wave in the fuel injection pump.