• Title/Summary/Keyword: Flow regulator

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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.

Delay Bound Analysis of Networks based on Flow Aggregation (통합 플로우 기반 네트워크의 지연시간 최대치 분석)

  • Joung, Jinoo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.1
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    • pp.107-112
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    • 2020
  • We analyze the flow aggregate (FA) based network delay guarantee framework, with generalized minimal interleaved regulator (IR) initially suggested by IEEE 802.1 time sensitive network (TSN) task group (TG). The framework has multiple networks with minimal IRs attached at their output ports for suppressing the burst cascades, with FAs within a network for alleviating the scheduling complexity. We analyze the framework with various topology and parameter sets with the conclusion that the FA-based framework with low complexity can yield better performance than the integrated services (IntServ) system with high complexity, especially with large network size and large FA size.

Multi-function Control of Hydraulic Variable Displacement Pump with EPPR Valve (전자비례감압밸브를 이용한 가변용량형 유압펌프의 다기능 제어)

  • Jung, Dong-Soo;Kim, Hyong-Eui;Kang, E-Sok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.6
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    • pp.160-170
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    • 2006
  • If hydraulic pump controlled by mechanical type regulator has more than one control function, the construction of regulator will be very complicated and control performance falls drastically. It is difficult to have more than one control function for hydraulic pump controlled by electronic type hydraulic valve due to the inconsistency of controllers. This paper proposes a multi-function control technique which controls continuously flow, pressure and power by using EPPR(Electronic Proportional Pressure Reducing) valve in swash plate type axial piston pump. Nonlinear mathematical model is developed from the continuity equation for the pressurized control volume and the torque balance for the swash plate motion. To simplify the model we make the linear state equation by differentiating the nonlinear model. A reaction spring is installed in servo cylinder to secure the stability of the control system. We analyze the stability and disturbance by using the state variable model. Finally, we review the control performances of flow, pressure and power by tests using PID controller.

The Screening Condition for the Immune Regulatory Responsor Using Mouse Fetal Thymic Organ Culture (쥐의 태아 흉선 조직 배양을 이용한 면역조절제 검색방법 확립)

  • Lee, Seung-Gak;Song, Min-Dong;Lee, Kwang-Ho
    • Korean Journal of Pharmacognosy
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    • v.28 no.4
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    • pp.286-292
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    • 1997
  • We studied the screening condition for immune regulatory responsor. We focused on the T-lymphocytes leer this purpose. Mouse fetal thymic organ culture (FTOC) system and flow cytometric analysis were mainly used in this experiment. Even if FTOC is carried out in vivo condition, the pattern of thymic development in the condition of FTOC is similar to that of in vivo condition. In this regard, FTOC system might be very powerful tool to screen the immune regulator, especially concerning on T cells. To establish the optimum condition of FTOC to screen the Immune regulator, we focused on the optimum amount of dose and culture period. The cell number and surface antigens on T cells were also analysed by using hemacytometer and flow cytometer. To monitor the differentiation event, anti-CD3, anti-CD4 and anti-CD8 antibodies were used. Alkoxyglycerol and Phellodendri Cortex were used fur positive and negative control, respectively. Astragalus membranceus was used as test sample. From our analysis, we reached to conclusions that the best dose of extract is $50\;{\mu}g/ml$ of culture medium, the best culture period is for 9 days, and ethanol used as solvent has no toxicity to FTOC.

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Investigation of Control Theory on Pressure Drop Characteristics of Pneumatic Regulator for Gas Supply (공압 레귤레이터의 공급압력 강하 제어이론에 대한 고찰)

  • Cho, Nam-Kyung;Chung, Yong-Gahp;Cho, In-Hyun
    • Journal of the Korean Society of Propulsion Engineers
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    • v.15 no.2
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    • pp.74-83
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    • 2011
  • For launcher applications, different from other applications, very high flow rate is required which can lead to supply pressure drop against required setting pressure. The supply pressure decrease is closely related to regulator characteristics. In this paper, supply pressure offset is investigated considering regulators as kinds of control systems. Pressure offset of self-operated regulator is analyzed with sensitive parameter defined as the ratio of valve travel to pressure offset. It is shown that pressure offset of self-operating regulator can be improved by incorporating proportional and integral controls and they can be materialized with pilot regulator systems.

A Study on the Characteristics of High Pressure Regulator for Vehicle CNG (자동차 CNG용 고압 레귤레이터의 특성해석에 관한 연구)

  • Kim, Byeong-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.12
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    • pp.5997-6003
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    • 2011
  • To increase the driving distance of a natural gas vehicle, the high pressure of fuel charge is necessary and the development of the device reducing the pressure to suitable pressure for fuel of high pressure. In this study, Pressure characteristics at the pressure regulator, which is very important for gas supply systems for vehicles, are investigated. Numerical simulations are carried out to quantify pressures at regulators for several flow rates and to investigate pressure drop, hysteresis losses at some parts in the pressure regulator. Moreover, this paper presents a new kind of hydraulic simulation which is composed of CNG regulator. Lastly, experiments are carried out to verify the effectiveness of the prosed mathematical simulation with various regulator components as in real working condition.

Voltage regulator for baseband channel selection filters (기저대역 채널선택 필터를 위한 전압 안정화 회로)

  • Kim, Byoung-Wook;Kim, Dae-Ik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.11
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    • pp.1641-1646
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    • 2013
  • Control voltage for baseband channel selection filter to select one of communication channels can be easily fluctuated according to external noise or variation of fabrication. In this paper, we design a voltage regulator with small chip area to keep control voltage constantly using current comparative method. Cut-off frequency of channel selection filter is automatically controlled by detecting current flow using the proposed voltage regulator.

Smoothing DRR: A fair scheduler and a regulator at the same time (Smoothing DRR: 스케줄링과 레귤레이션을 동시에 수행하는 서버)

  • Joung, Jinoo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.1
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    • pp.63-68
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    • 2019
  • Emerging applications such as Smart factory, in-car network, wide area power network require strict bounds on the end-to-end network delays. Flow-based scheduler in traditional Integrated Services (IntServ) architecture could be possible solution, yet its complexity prohibits practical implementation. Sub-optimal class-based scheduler cannot provide guaranteed delay since the burst increases rapidly as nodes are passed by. Therefore a leaky-bucket type regulator placed next to the scheduler is being considered widely. This paper proposes a simple server that achieves both fair scheduling and traffic regulation at the same time. The performance of the proposed server is investigated, and it is shown that a few msec delay bound can be achieved even in large scale networks.

Pressure Regulator for Piezoelectric Valve (압전 밸브용 압력 레귤레이터)

  • Yun, S.N.;Kim, C.Y.;Seo, S.W.;Park, J.H.;Ham, Y.B.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.3 no.2
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    • pp.1-6
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    • 2006
  • The pressure regulator which is used for controlling the reducing pressure in the piezoelectrically driven pneumatic valve has been studied. The pneumatic valve of this study object is 2-stage type and consists of a piezoelectric actuator, a controller, a poppet valve and a pressure regulator. Nominal flow of 50 lpm, maximum operating pressure of 0.9MPa and frequency characteristic of 10Hz and over are required in this pneumatic valve, but the pressure regulator is needed because piezoelectric actuator has no ability to control the pressure of 0.9MPa directly. In this study, bimorph type PZT actuator of $25.2mm(L){\times}7.2mm(W){\times}0.5mm(H)$ with constant of $-220{\times}10-12$ CN-1 was proposed and investigated. Maximum operating force of 0.052 N and maximum displacement of $63{\mu}m$ were gotten from the fabricated PZT actuator. From the analysis results, the orifice diameter of 0.6mm for a piezoelectric actuator was derived and then the pressure regulator which can be operated under 0.15 MPa easily was designed and manufactured. Performance and effects of design parameters were simulated by the Simulink of Matlab software, and it was confirmed that the performance characteristics of manufactured pressure regulator are superior in the common use pressure range of 0.5 MPa to 0.7 MPa. The results show that the proposed pressure regulator is suitable for the pneumatic valve with a PZT actuator.

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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.