• Title/Summary/Keyword: Fuel pressure control

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Fuel flow simulation in globe valve considering variation of viscosity (연료의 점도 변화를 고려한 글로브 밸브 내부 유동 시뮬레이션)

  • Phil Kim;Jeongbeom Heo;Haebeen Kim;Eunseop Yeom
    • Journal of the Korean Society of Visualization
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    • v.22 no.3
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    • pp.54-59
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    • 2024
  • Valves are devices used to control or stop the flow of fluids through pipelines. Among them, globe valves with a movable disk or plug experience a significant pressure drop due to the changes in fluid flow direction from horizontal to vertical and back to horizontal. This study analyzes the flow characteristics and cavitation in a globe valve, focusing on the effects of varying fuel viscosity due to changes in pressure and temperature. Simulations were conducted with IFO 380 fuel under constant and variable viscosity conditions. The Realizable k-ε model was applied, and cavitation was simulated through multiphase flow conditions. Results showed that at a 50% valve opening, significant pressure drops and cavitation occurred in narrow regions, while at 100%, pressure changes were more gradual. The WLF-Barus model revealed that higher pressures increased fuel viscosity, reducing cavitation compared to constant viscosity conditions. Flow coefficient (Kv) calculations showed minor differences between constant and variable viscosity, with the variable condition leading to a lower Kv at full valve opening. The study highlights the impact of viscosity changes on flow resistance and cavitation behavior.

A Study on Correlation between A/F and ion signal in a Constant-Volume Chamber Using Spark-plug Ionization Probe Itself (정적챔버에서 스파크 플러그 이온프로브를 이용한 공연비와 이온신호와의 상관관계에 대한 연구)

  • Park, Jong-Il;Chun, Kwang-Min;Hahn, Jae-Won;Park, Chul-Woong
    • 한국연소학회:학술대회논문집
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    • 2002.11a
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    • pp.223-229
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    • 2002
  • Spark plug ionization signal could be useful in an internal combustion engine as a feedback signal for combustion diagnostics such as misfire detection, knocking detection and lambda control, but the signal has high level of cyclic fluctuation in an internal combustion engine due to residual gas, pressure, temperature, mixture composition in the spark gap. Because of this reason it is very difficult to apply ion signal to commercial engine control. In this Study, a correlation between A/F and spark plug ionization signal was studied in a constant volume chamber. Constant volume chamber with gas phase fuel(Propane) has homogeneous fuel composition , no mixture flow, same pressure and temperature on each test. The results show that mean chemi-ion signal has the highest correlation with A/F and intial pressure change has on effect on the thermal-ion signal and not on chemi-ion signal.

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A Study on Combustion and Emission Characteristics in Compression Ignition CRDI Diesel Engine (직접분사식 압축점화 디젤엔진의 연소 및 배기특성에 관한 연구)

  • Kim, Gi-Bok;Choi, Il-Dong;Ha, Ji-Hoon;Kim, Chi-Won;Yoon, Chang-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.17 no.4
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    • pp.234-244
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    • 2014
  • Recently it has been focused that the automobile engine has developed in a strong upward tendency for the use of the high viscosity and poorer quality fuels in achieving the high performance, fuel economy, and emission reduction. Therefore it is not easy to solve the problems between low specific fuel consumption and exhaust emission control at motor cars. In this study, it is designed and used the engine test bed which is installed with turbocharger and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and exhaust emission as operating parameters, and they were engine speeds(rpm), injection timing(bTDC), and engine load(%). From the result of an experimental analysis, peak cylinder pressure and the rate of pressure rise were increased, and the location of it was closer toward top dead center according to the increasing of engine speed and load, and with advancing injection timing. The combustion characteristics are effected by fuel injection timing due to be enhanced the mass burned fraction. Using the engine dynamometer for analyzing the engine performance, the engine torque and power have been enhanced according to advancing the fuel injection timing. In analyzing of exhaust emission, there has been a trade-off between PM and NOx with increasing of engine speed and load, and with advanced injection timing. The experimental data are shown that the formation of NOx has increased and PM, vice versa.

Improvement of Fuel Economy in a Diesel Engine by Application of Low Pressure EGR System (디젤 엔진의 연비 향상을 위한 저압 배기재순환 시스템의 적용에 관한 연구)

  • Kim, Yongrae;Lee, Yonggyu
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.2
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    • pp.81-87
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    • 2015
  • LP(low pressure)-EGR system was investigated to evaluate its potential on fuel economy improvement and NOx emission reduction in a diesel engine. A diesel engine was tested for the evaluation of LP-EGR system at both of steady-state and transient test. For a transient test, control logic for LP-EGR valve operation was developed and a NEDC mode test was conducted by using a vehicle status simulation test. The steady-state results showed that LP-EGR system can reduce more NOx emission or fuel consumption comparing to the conventional HP(high pressure)-EGR. From the NEDC mode test, this LP-EGR system showed a possibility to improve fuel economy without a penalty of emissions.

Analysis of Hot Forging Process of Check Valve in FCEV using Finite Element Method (유한요소법을 이용한 FCEV용 체크밸브의 열간 단조 공정 해석)

  • Jung, Dong-Hwan;Song, Hyun-Jung;Lee, Chang-Hoon;Lee, Seung-Beom;Kim, Ji-Hoon;Shon, Keun-Joo;Cho, Hae-Yong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.11
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    • pp.100-107
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    • 2021
  • The use of new and renewable energy is essential to solve the problem of increasing fossil fuel use due to industrial development. The paradigm of the automobile industry has changed due to the strengthening of environmental regulations in developed countries, and the development of eco-friendly cars is underway. Fuel cell electric vehicles (FCEVs), which use hydrogen as fuel, require strict standards for fuel-related components. In particular, check valves for FCEV control high-pressure hydrogen and thus, must be sufficiently strong for the challenging environment caused by high-pressure hydrogen. Therefore, this study used DEFORM 3D, a regular finite element analysis program, to check the moldability of check valves for FCEV, design the process, verify reliability through single streamline analysis, tensile tests, and ANSYS simulations, and identify suitable materials for the high-pressure hydrogen environment.

Weed Control by Flame (화염을 이용한 잡초방제 연구)

  • 姜和錫;文學洙
    • Journal of Biosystems Engineering
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    • v.26 no.4
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    • pp.331-336
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    • 2001
  • This study was to develop a kerosene flame weeder. An air compressor was driven though the PTO of a tractor to provide necessary air for fuel combustion and proper pressure to supply fuel from fuel tank to the nozzle. It was found that the flame was extinguished very easily by wind and vibration of the tractor. This trouble could be solved by attaching a burner cap, which is a modified venturi tube, at the end of the nozzle. The constructed flame weeder was tested for the weeding capability in the prepared field. Weed extinction rate and weight decrease rate were analysed. Measured maximum flame temperature was 1,121\^C when the fuel consumption was 13.41 kg/h and fuel supply pressure was 88.2 kPa. The maximum temperature occurred at 20cm from the front end the burner, and it decreased to 46\^C as the distance increased to 110cm. The flame length of up to 70cm, where the flame temperature was higher than 372\^C, would be used for weeding purpose. Weed extinction rate and weight decreasing rate increased as the fuel consumption increased. The flame weeder was evaluated to be a practical weeder through improvement as the weed extinction rate and weight decrease rate were analysed to be 75% and 85%, respectively when the fuel consumption was 116.87kg/ha.

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A Study on In-cylinder and Combustion Characteristics of GDI Engine using RCEM (급속 압축팽창 장치를 이용한 직접분사식 가솔린 기관의 실린더 내 분무 및 연소특성에 관한 연구)

  • 조규백;정용일
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.76-85
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    • 1999
  • GDI(Gasoline Direct Injection( engine technology is well known as a new technology since it can improve fuel consumption and meet future emission regulations. But the GDI has many difficulties to be solved, such as complexity of injection control mode, unburned hydrocarbon, and restricted power. A 2-D shape combustion chamber was adopted to investigate mixture formation and combustion characteristics of GDI engine. Spray and combustion experiments were performed by changing the injection timing. injection pressure an din-cylinder flow in Rapid Compression and Expansion Machine(RCEM).Through the experiments, the detailed characteristics of fuel spray and combustion was analyzed by visualizing the in-cylinder phenomena according to the change of injection condition, and the optimal fuel injection timing and fuel injection pressure were obtained.

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The Effect of Exhaust System Components on the Sl Engine Performance (배기구성요소가 SI기관의 성능에 미치는 영향)

  • Park Kyoungsuk;Park Sejong;Son Sungman
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.6 s.171
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    • pp.192-198
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    • 2005
  • Recently, Automobile manufacturers regarding stability, economic environmental-friendly problems by the development of automobile. This reason is increasingly strict environmental regulations to lower fuel consumption and reduce emission. Designing more efficient and low emission control exhaust system results in more efficient Performance, reduced back Pressure and higher convert efficiency. Also to reduce the noise and the vibration of the automobile. According to develop variable type muffler, dual muffler and active intelligence exhaust system unit. Improvement in engine performance and fuel consumption rate, higher conversion efficiency demand information of pressure fraction and heat characteristics. To be able to determine these factor fur we experiment on each case of exhaust system unit. In this study, how back pressure is distributed in flow-through in exhaust system and how to design exhaust system flexibleness, efficiency, lower back pressure and optimal performance. This study furnish basic data for engineers, technicians.

Control of Combustion Instabilities in a Gas Turbine Combustors Through Secondary Fuel Injection (가스터빈 연소기내 2차연료분사에 의한 연소 불안정성의 제어)

  • Jeon, C.H.;Santavicca, Domenic A.
    • Journal of the Korean Society of Combustion
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    • v.3 no.1
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    • pp.59-69
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    • 1998
  • The results of study on the active control of naturally occurring combustion oscillations with a single dominant frequency in an atmospheric dump combustor are presented. Control was achieved by an oscillatory infection of secondary fuel at the dump plane. A high speed solenoid valve with a maximum frequency of 250Hz was used as the actuator and a sound level meter, located at the combustor exit, measured the pressure fluctuations which served as the feedback signal for the control loop. Instability characteristics were mapped over a range of mean mixing section velocities from 6.7 m/s-9.3 m/s and with three mixing conditions. Different fuel/air mixing conditions were investigated by introducing varying percentages of primary fuel at two locations, one at the entrance to the mixing section and one 6 mixing tube diameters upstream of the dump plane. Control studies were conducted at a mean velocity of 9.3 m/s, with an air temperature of 415C, and from flame blowout to the stoichiometric condition.

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Characteristics of Flow Rate Control for Solid Fuel Gas Generator (고체연료를 사용하는 가스발생기 유량조절특성 연구)

  • Choi, Ho-Jin;Hyun, Hyung-Soo;Lee, Kyoung-Ho;Park, Ik-Soo;Lee, Jae-Youn;Youn, Hyun-Gull;Lim, Jin-Shik
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.293-298
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    • 2011
  • The combustion and flow-rate control characteristics of fuel-rich gas generator which could be adopted to Ducted Rocket propulsion system are investigated. The gas generator is designed considering the design requirements of propulsion system and solid fuel for fuel-rich combustion is developed then adopted to ground test. The results of combustion test show the necessity of the special analysis tool for estimating the gas generator performance where multi-phase flow of fuel-rich gas exists. During the flow-rate control test, characteristics of gas generator pressure with the angle of valve are analyzed and, method to estimate the pressure of gas generator is suggested using the relation between the valve exit area and discharge coefficient.

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