• Title/Summary/Keyword: injection pressure

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A Developement of Ultra High Pressure Injection Equipment for Study on Diesel Spray Characteristics with Ultra High Pressure (극초고압 디젤분무특성 해석을 위한 극초고압 단발분사장치의 개발)

  • 정대용;이종태
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.50-59
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    • 2003
  • It was known that high pressure injection is an effective method to enhance thermal efficiency and decrease exhaust emissions in diesel engines. If injection pressure becomes ultra high, it is predicted that there may be a suitable injection pressure which the enhancement rate of spray characteristics is moderate. Also, there may be a limit injection pressure which spray characteristics is reversed and get worse. But these are unknown. To investigate a suitable injection pressure and a limit injection pressure, ultra high pressure injection equipment(UHPIE), which can realize the injection pressure of 3,200bar, was developed. UHPIE is a basic apparatus of single shot injection, and ultra high pressure was achieved by second stage rapid compression in short time. From the evaluation of UHPIE, a injection curve like a conventional diesel engine(jerk type) was realized. Also, it was proved that repetition of experiment was excellent. Therefore it was found that there was no problem to perform the study on the ultra high pressure injection with UHPIE. Consequently, the foundation of the study on ultra high pressure injection could be established.

Study on the Injection Characteristics using Injection Rate in a Direct-injection Gasoline Injector with Multi-hole (분사율을 이용한 직접 분사식 다공 가솔린 인젝터의 분사특성 연구)

  • Park, Jeonghyun;Shin, Dalho;Park, Su Han
    • Journal of ILASS-Korea
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    • v.21 no.1
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    • pp.20-28
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    • 2016
  • This paper presents an experimental study on the GDI injector with Bosch method. The injection characteristics, such as the injection quantity, the injection rate, the maximum velocity of the nozzle exit and the injection delay were studied through the change of the injection pressure, the tube pressure and energizing duration in injection rate measurement device using nheptane. The injection quantity is increased by increasing injection pressure, decreasing tube pressure or increasing energizing duration. As the difference of the injection quantity changed, the shape of injection rate was moved with a constant form. The maximum velocity of the nozzle exit showed a tendency to increase as the injection pressure is increased. However, tube pressure did not affect. Overall, it was confirmed that the closing delay is longer than the opening delay in all conditions. As the injection pressure increased, the result has a tendency to decrease the closing delay, it did not affect the opening delay. Reduction of the closing delay showed the reduction of the injection duration. the tube pressure and energizing duration did not affect the injection delay (opening delay, closing delay).

Variations of Temperature and Pressure in the Cavity for Operational Conditions of Injection Molding (사출성형의 공정변수에 따른 캐비티 내의 온도와 압력의 변화)

  • Kim S. W.;Park H. C.;Lyu M.-Y.;Jin Y. S.;Kim D.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.10a
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    • pp.70-74
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    • 2004
  • Pressure and temperature in the cavity of injection molding have been investigated. Special injection mold was designed to install pressure and temperature sensors. The sensors were supplied by KISTLER and the pressure and temperature were measured for various operational conditions, such as injection pressure, holding pressure, cooling time, mold temperature, and injection temperature. As injection pressure increased cavity pressure and temperature increase. There were no big differences in temperatures according to the holding pressures. As mold temperature increased pressure and temperature in the cavity increase. The flowability of resin increases as mold temperature increases subsequently the pressure in the cavity increases since the pressure loss is less in the low viscous medium than high ciscous medium. The cavity temperature highly depends upon mold temperature.

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Computer Simulation of the Electronic Hydraulic Ultra - High Pressure Fuel Injection System (전자유압식 초고압 연료분사계의 시뮬레이션에 관한 연구)

  • Jang, Se-Ho;Ahn, Su-Gil
    • Journal of Advanced Marine Engineering and Technology
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    • v.20 no.5
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    • pp.82-92
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    • 1996
  • A computer simulation with predict the fuel injection rates and the fuel injection pressure behaviors in diesel engine fuel injection systems would by very useful in designing or improving fuel injection systems. In this paper we developed computer program in order to predict the behaviors of the fuel injection rate and the injection pressure for Electronic Hydraulic Ultra-High Pressure Fuel Injection System. We've applied the continuity and momentum equations for the hydraulic phenomena and the dynamics of individual components of the Electronic Hydraulic Fuel Injection System. To solve all the equations numerically we've applied the Runge-kutta IV method. Water hammer equations were applied for the hydraulic pipe solution, and the method of characteristics was employed in our calculations. The simulation results were compared with the experimental results for: Accumulator pressure, Injection pressure and unjection rate. As a result, The simulation results agree very well with our experimental results. We found that a large accumulator and the high speed solenoid valve were required, and the compression volume of the fuel had to be as small as possible in order to acheive ultra-high pressure fuel injection.

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A Study on Suitable Injection Pressure of Ultra High Pressure Injection System (초고압 분사의 적정분사압력에 관한 연구)

  • Jeong, D.Y.;Park, S.J.;Kim, H.J.;Lee, Jong-T.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.913-918
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    • 2000
  • Spray and combustion characteristics were investigated to find suitable injection pressure by using ultra high pressure injection and single shot diesel combustion systems. As injection pressure was increased, spray penetration and spray angle were increased continuously until 2,000bar, but after this injection pressure region the rate of increase was decreased suddenly. Combustion characteristics were also enhanced until 2,000bar of injection pressure.

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ANALYSIS OF THE SUITABLE INJECTION PRESSURE FOR DIESEL INJECTION WITH HIGH PRESSURE

  • JEONG D. Y.;LEE J. T.
    • International Journal of Automotive Technology
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    • v.6 no.2
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    • pp.87-93
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    • 2005
  • Spray patterns were visualized using the shadowgraph method, and the droplet size and velocity were measured using PDPA for high-pressure injections up to 2,600 bars. The spray pattern and spray characteristics, such as penetration, spray width, spray angle, droplet size, injection duration, and droplet velocity, were investigated to determine the suitable injection pressure. Spray penetration, width, angle, and velocity increased continuously up to 2,600 bars with the injection pressure in a high-pressure region. The rate of improvement of the above spray characteristics, however, declined rapidly, when the injection pressure reached 2,000 bars. The injection duration and droplet size generally decreased with the increase in the injection pressure, while the rate of improvement decreased abruptly after 2,000 bars. Consequently, the improvement rate of the spray characteristics became blunt at over 2,000 bars. This means that the suitable injection pressure is around 2,000 bars.

A Study on the Combustion Characteristic and Soot Distribution of a Common Rail Type D.I.Diesel Visualized Engine with Pilot Injection (파일럿 분사시의 커먼레일식 직분식 가시화 디젤엔진의 연소 및 Soot분포 특성에 관한 연구)

  • 이재용;한용택;이기형;이창식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.6
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    • pp.37-43
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    • 2003
  • The objective of this work is to investigate the effect of swirl, injection pressure and pilot injection on D.I. diesel combustion by using a transparent engine system. The test engine is equipped with common rail injection system to obtain high pressure and to control injection timing and duration. In this study, the combustion analysis and steady flow test were conducted to estimate the heat release rate from in-cylinder pressure. Soot distribution in diffusion flame according to swirl ratio, injection pressure and pilot injection was investigated by using LII technique. As the results, high injection pressure was found to shorten ignition delay as well as enhance peak pressure and heat release rate was greatly affected by injection timing and pilot injection. In addition, the results showed that the period of soot formation corresponded to the diffusion flame.

A study on the spray characteristics of CRDI system with injection pressure (분사압력에 따른 CRDI 분사계의 분무특성에 관한 연구)

  • KIM, Sang-Am;WANG, Woo-Gyeong;YANG, Jung-Kyu
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.1
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    • pp.65-71
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    • 2016
  • Injection rate, injection quantity and injection timing of fuel are controlled precisely by electric control in CRDI system. Particularly, injection rate being influenced with injection pressure affects to spray characteristics and fuel-air ratio, so it is a very important factor in diesel combustion. In this study, injection rates in accordance with injection pressure at a constant ambient pressure were measured with Zeuch's method. Under the same condition, non-evaporating spray images were taken with a high speed camera and analyzed carefully with Adobe Photoshop CS3. Macroscopic spray characteristics and breakup processes in the spray could be found from the examined and analyzed data. Injection start time and injection period were practically affected with injection pressure. Also, initial injection rate, spray penetration, spray angle and breakup of high density droplets region in the spray were affected with injection pressure. The results and techniques of spray visualization and injection rate measurement in this study would be practically effective to study a high pressure diesel spray for common rail direct injection system.

Effect of Glass Fiber Contents on the Tensile Strength in Injection Molding Process (사출성형공정에서 유리섬유함유량이 인장강도에 미치는 영향)

  • 김영수;김인관
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.5
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    • pp.63-69
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    • 2000
  • The main target of this research is investigating the relations between mechanical properties and injection conditions, like injection pressure, packing pressure and packing time for various contents ratio of glass fiber and resin. In general idea, high injection pressure produces high strength of molded parts as a monotonic function. but it was revealed that high pressure does not make high strength directly through various experiments of injection molding. In this experiments, PA66 was selected as resin and Glass Fiber was selected as reinforcing fiber Fiber reinforcement was controlled, as 14%, 25%, 33%, 44% of total volume and packing pressure was divided 55%, 65%, 75%, 85% of reference pressure, i.e. 100% equal to 1400kgf/$\textrm{cm}^2$. Finally, tensile testing was executed for injected test specimen. Optimum results based on authors' experiments have been obtained under conditions of 25% and 33% of glass fiber contents. Tensile strength rather depends on the packing pressure and packing time than injection pressure. Especially almost equal value of tensile strength was obtained for various percentage of packing and injection pressure as 65%, 75% and 85% of reference pressure.

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Engine Performance and Combustion Characteristics on The Variation of Injection Characteristics in Diesel Engine with Common Rail System (디젤엔진에서 Common-rail 시스템의 분사방법에 따른 기관성능 및 연소특성에 관한 실험적 연구)

  • 백두성;오상기;한영출
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.4
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    • pp.52-57
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    • 2003
  • Common rail injection system is flexible in injection timing, injection duration and pressure in engine. Many researches have reported on the merits in the application of common rail systems. This research investigated on characteristics and performance for single cylinder diesel engine with a common .ail injection system by varying major parameters such as injection timing, injection duration and common rail pressure. The injection timing and injection duration were controlled by electronic pulse generated. and common rail pressure were controlled by PCV driver. The 498cc single cylinder diesel engine was used in this experiment. All data for combustion pressure, injection timing and injection duration were recorded by Labview. Furthermore, this test was focused on how to optimize injection conditions.