• Title/Summary/Keyword: Fuel pressure control

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Performance Prediction according to Equivalence Ratio Change in Simulated-EGR Compression Ignition Engine Containing CO2 (CO2를 포함한 Simulated-EGR 압축착화엔진에서 당량비 변화에 따른 성능 예측)

  • Suh, Hyun Kyu
    • Journal of ILASS-Korea
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    • v.25 no.1
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    • pp.21-26
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    • 2020
  • The objective of this work is to numerically reveal the effect of equivalence ratio change on the simultaneous reduction of NOX and soot emissions from the simulated-EGR compression ignition engine containing CO2. An experiment was conducted by using a single-cylinder common-rail injection system engine, an intake control system, and exhaust emissions analyzers. The numerical analysis results were validated under the same experimental conditions. To investigate the effect of equivalence ratio by simulated-EGR containing CO2, the O2, N2, and CO2 mole fraction were changed in the initial air conditions to the cylinder. The results were analyzed in terms of peak cylinder pressure, indicated mean effective pressure, indicated specific nitrogen oxide, and indicated specific soot. It was revealed that ignition delay characteristics and heat release rate (ROHR) characteristics were not significantly different according to the equivalence ratio. However, as the equivalence ratio increased from 0.68 to 0.83, the maximum combustion pressure and IMEP decreased by about 6.5% and 9.4%, respectively. In the case of ISFC, as is well known, the trend is opposite of IMEP. In the case of ISNO, as the equivalence ratio increased, less NO was generated, and as the equivalence ratio increased by 0.05, the ISSoot value of about 10% increased.

Study of Failure Examples for Emission Gas Control System in Gasoline Engine (가솔린 엔진 배출가스 제어장치에 대한 고장사례 고찰)

  • Lee, Il Kwon;Lee, Jong Ho;Lee, Young Suk;Youm, Kwang Wook;han, Jae Oh;Lim, Ha young
    • Journal of the Korean Institute of Gas
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    • v.20 no.6
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    • pp.37-42
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    • 2016
  • The purpose of this paper is to study for the emission gas control of passenger car. The first example, the PCSV never open when operating condition, but it opened by causing malfunction because of trouble. As a result, the purge gas entered into surge tank, a mount of fuel was displayed with excessive supply on tester. Therefore, it certified the bad-condition of the engine when idling by decreasing of fuel injection quantity from engine ECU. The second example, the hose activating a EGR valve didn't supply the vacuum pressure because of assembling the other part. Thus, it knew the bad-condition of engine that the EGR valve would not work normally by leaking with the other port. The third example, as the rear oxygen sensor of two sensor were fault-installing by changing the sensor of other a car it could not detect of oxygen quantity. Finally, it found the phenomenon of abruptly decreasing vehicle speed when braking a car. Therefore, the system including with emission control has to drastically manage by maximizing condition to role decreasing the emission gas.

A Study on Buzz Margin Control in Supersonic Engine Intake using PID Controller (PID 제어기를 이용한 초음속 엔진 흡입구의 버즈마진 제어에 관한 연구)

  • Kong, Chang-Duk;Ki, Ja-Young;Kho, Seong-Hee;Kang, Myoung-Cheol
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.05a
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    • pp.88-92
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    • 2009
  • Total pressure recovery ratio in intake is crucial factor to the operational characteristics of supersonic propulsion system because it does not compress inlet air mechanically by compressor, but does compress inlet air by ram compression. As the result of that the dynamic characteristic analysis of engine was performed before the controller was designed, it could be ascertained when the AoA of flight vehicle increases, the buzz margin decreases so that the shock wave produced outside intake in the specified area according to flight operation's characteristics. Therefore the PID control algorithm was designed to be controlled buzz margin that the characteristic of shock wave could meet the requirement of performance in intake. The PID controller was designed that the buzz margin value is being positive number using the control variables; fuel flow and nozzle throat area.

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Analysis of Fast Injection Response Characteristics Between Solenoid and Piezo-Driven Injector (솔레노이드 및 피에조 인젝터의 고속분사 응답성 해석)

  • Jo, In-Su;Lee, Jung-Hyup;Lee, Jin-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.10
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    • pp.971-977
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    • 2012
  • It is well known that the performance of a diesel injector is directly related to the power, emission, and fuel consumption of the diesel combustion engine. In this study, the injection response characteristics of CRDi injectors driven by a solenoid coil and a piezoceramic were investigated by using the AMESim simulation code. Some analytical parameters such as the fuel pressure and hole diameter were considered. From this study, it was shown that the piezo-driven injector had a faster response and had better control capability than the solenoid-driven injector. In addition, it was found that the piezo-driven injector can be utilized more effectively in a multiple injection scheme than a solenoid-driven injector.

Application of discrete wavelet transform to prediction of ram stuck phenomena

  • Byun, Seung-Hyun;Cho, Byung-Hak;Shin, Chang-Hoon;Park, Joon-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1445-1449
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    • 2005
  • The ram assembly is important equipment in fueling machine of PHWR(Pressurized Heavy Water Reactor) plant where fuel replacement is possible while the plant is in service. Troubles in the ram assembly can cause lots of difficulties in power plant operation. The ram assembly is typically composed of the B-ram, the L-Ram and the C-Ram. The B-ram is focused in this paper because it plays the most important role in the ram assembly. Among the ram fault phenomena, ram stuck phenomena are the most frequent cases in the B-ram, which has a ball screw mechanism driven by a hydraulic motor. Ram stuck phenomena are due to ball wear and damage in ball nut that increase in proportion to the number of fuel replacement. It is required to predict ram stuck phenomena before they occur. In this paper, a method is proposed for predicting ram stuck phenomena using a discrete wavelet transform. The discrete wavelet transform provides information on both the time and frequency characteristics of the input signals. The proposed method uses the frequency bandwidths of coefficients of discrete wavelet decompositions and detail coefficients of discrete wavelet transform to predict ram stuck phenomena. The signal used in this paper is a torque-related signal such as a hydraulic service outlet pressure signal in a hydraulic driving system or a current signal in a DC motor driving system. Finally, the validity of the proposed method is shown via experiment using ball nut characteristic test equipment that simulates ram stuck phenomena due to increased ball friction in ball nut.

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Experimental Study on the Spray Characteristics of the Diesel Single Hole Type Nozzle (디젤단공노즐의 분무특성에 관한 실험적 연구)

  • 안병규;송규근;윤소남;최병오
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.764-767
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    • 2003
  • The characteristics of diesel spray have much effect on the engine performances such as power. fuel consumption rate and emissions. Therefore, the measurement of fuel spray characteristics is very important for the improvement of heat engine. The factors which control diesel spray characteristics are injection pressure, ambient temperature and density etc. Spray behaviors are visualized by using the high speed video camera and spray angle, spray penetration are measured. Experimental equations of spray penetration and spray angle were derived by using the experimental results. 1) Ambient temperature and density influence on the characteristics of diesel spray. 2) Experimental equation of spray penetration is expressed as follows 0<t< tbtb ; S1S1=11.628ΔΔ P0.485P0.485 ρρaa 0.4780.478 t1.337t1.337, tbtb <t; S2S2=7.457ΔΔ P0.523P0.523 ρρaa 0.3820.382 t0.548t0.548 3) Experimental equation of spray Angie is expressed as follows TaTa =293K; Tan(θθ/2)=059(ρρaa / ρρff )0.4370.437, TaTa =473K; Tan(θθ/2)=0588(ρρaa / ρρff )0.4040.404_{f}$ )0.4040.404

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A Study on PM Regeneration Characteristics of Diesel Passenger Vehicle with Passive Regeneration DPF System (자연재생방식 DPF시스템 부착 경유승용차량의 PM재생 특성 연구)

  • Lee, Jin-Wook;Cho, Gyu-Baek;Kim, Hong-Suk;Jeong, Young-Il
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.2 s.257
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    • pp.188-194
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    • 2007
  • New diesel engines equipped with common-rail injection systems and advanced engine management control allow drastic decreases in the production of particulate matters and nitrogen oxides with a significant advantage in terms of the fuel consumption and CO2CO2 emissions. Nevertheless, the contribution of exhaust gas after treatment in the ultra low emission vehicles conception has become unavoidable today. Recently the passive type DPF(Diesel Particulate Filter Trap) system for diesel passenger vehicle has been manufactured into mass production from a French automotive maker since the year of 2000. This passive DPF system fully relies on the catalytic effects from additives blended into the diesel fuel and additives injected into the DPF system. In this study, the effects of PM regeneration in the commercial diesel passenger vehicle with the passive type DPF system were investigated in chassis dynamometer CVS(constant volume sampler)-75 mode. As shown in this experimental results, the DPF regeneration was observed at temperature as low as 350C350C. And the engine-controlled the DPF regeneration founded to be one of the most promising regeneration technologies. Moreover, the durability of this DPF system was evaluated with a season weather in terms of the differential pressure and exhaust gas temperature traces from a road test during the total mileage of 80,000km.

Study on the Short Resistance and Shorting of Membrane of PEMFC (PEMFC 고분자 막의 Short 저항 및 Shorting에 관한 연구)

  • Oh, Sohyeong;Gwon, Jonghyeok;Lim, Daehyeon;Park, Kwonpil
    • Korean Chemical Engineering Research
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    • v.59 no.1
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    • pp.6-10
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    • 2021
  • The shorting resistance (SR) of the PEMFC(Proton Exchange Membrane Fuel Cell) polymer membrane is an important indicator of the durability of the membrane. When SR decreases, shorting current (SC) increases, reducing durability and performance. When SR becomes less than about 0.1 kΩ·㎠, shorting occurs, the temperature rises rapidly, and MEA(Membrane Electrode Assembly) is burned to end stack operation. In order to prevent shorting, we need to control the SR, so the conditions affecting the SR were studied. There were differences in the SR measurement methods, and the SR measurement method, which improved the DOE(Department of Energy) and NEDO(New Energy and Industrial Technology Development Organization) method, was presented. It was confirmed that the SR decreases as the relative humidity, temperature and cell compression pressure increase. In the final stage of the accelerated durability evaluation process of the polymer membrane, SR rapidly decreased to less than 0.1 kΩ·㎠, and the hydrogen permeability became higher than 15 mA/㎠. After dismantling the MEA, SEM(Scanning Electron Microscope) analysis showed that a lot of platinum was distributed inside the membrane.

A STUDY ON INTERNAL FLOW CHARACTERISTICS OF PCV VALVE ACCORDING TO SPOOL DYNAMIC BEHAVIOR (PCV 밸브의 스풀 동적거동에 따른 내부유동 특성에 관한 연구)

  • Lee J.H.;Lee Y.W.;Kim J.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.10a
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    • pp.223-227
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    • 2005
  • A PCV valve is a part to control the flow rate of Blowby gas in a PCV system. A PCV system re-burns Blowby gas with fuel in a combustion chamber. Some gas enters to a crankcase room through the gap between piston ring and engine cylinder wall. This gas si called 'Blowby gas'. This gas causes many problems. In environmental view, Blowby gas includes about 25\~35%25\~35% hydrocarbon{HC) of total generated HC in an automobile. Hydrocarbon is a very harmful pollutant element in our life. In mechanical view, Blowby gas has some reaction with lubricant oil of crankcase room. Then, this causes lubricant oil contamination, crankcase corrosion and a decrease fo engine efficiency. Consequently, Blowby gas must be eliminated from a crankcase room. In this study, we simulated internal flow characteristics in a PCV valve according to spool dynamic behavior using local remeshing method And, we programmed our sub routine to simulate a spool dynamic motion. As results, spool dynamic behavior is periodically oscillated by the relationship between fluid force and elastic force of spring. And its magnitude is linearly increased by the differential pressure between inlet and outlet. Also, as spool is largely moved, flow area is suddenly decreased at orifice. For this reason, flow velocity is rapidly decreased by viscous effect.

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A Study on Design and Application of High Response Solenoid for Unit Injector (유닛인젝터용 고속응답 솔레노이드 설계 및 응용에 관한 연구)

  • 황재원;양이진;정영식;이상만;채재우
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.1
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    • pp.43-51
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    • 1998
  • Most of fuel-injection system operated with mechanical methods are difficult to control the injection quantity and injection timing as well as injection rate exactly. Moreover high pressure injection scheme is never be realized with conventional one. On the other hand, serious air pollution can be lessened with injection system equipped with those functions. Therefore, electronically controlled Unit Injuctor(UI) appeared to satify above mentioned desires. However, it is still difficult that the most important part, especially solenoid valve, is analyzed precisely, because of the existence of complex combination of electromagnetics, electrics and dynamic problems. In this study, experimental and theoretical analysis are accomplished for understanding of solenoid valve characteristics and further its design. As the result, the follows are obtained 1) As the increase of wire diameter, the response time became shorter and optimal inductance existed in relative with the response time and wire diameter. 2) According to increasing input voltage, the traction force increased, otherwise the response time was shortened. 3) As the increase of armature stroke, the traction force decreased and the response time became longer.

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