• 제목/요약/키워드: Air injection

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Performance and Emission Characteristics of a Controlled Auto-Ignition Gasoline Engine according to Variation of the Injection Timing (분사시기의 변화에 따른 제어자발화 가솔린기관의 성능 및 배기특성)

  • Kim, H.S.
    • Journal of Power System Engineering
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    • v.9 no.1
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    • pp.14-22
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    • 2005
  • This work deals with a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. The fuel is injected indirectly into electrically heated inlet air flow. In order to keep a homogeneous air-fuel mixing, the fuel injector is water-cooled by a specially designed coolant passage. Investigated are the engine performance and emission characteristics under the wide range of operating conditions such as 40 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, $150\;to\;180^{\circ}C$ in the inlet-air temperature, and $80^{\circ}$ BTDC to $20^{\circ}$ ATDC in the injection timing. A controlled auto-ignition gasoline engine can be achieved that the ultra lean-burn with self-ignition of gasoline fuel by heating inlet air. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxide had been significantly reduced by CAI combustion compared with conventional spark ignition engine.

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Effects of Gas Injection on the Heating Performance of a Two-Stage Heat Pump Using a Twin Rotary Compressor with Refrigerant Charge Amount

  • Heo, Jae-Hyeok;Jeong, Min-Woo;Jeon, Jong-Ug;Kim, Yong-Chan
    • International Journal of Air-Conditioning and Refrigeration
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    • v.16 no.3
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    • pp.77-82
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    • 2008
  • For heat pumps used in a cold region, it is very important to obtain appropriate heating capacity. Several studies using a variable speed compressor and an additional heater have been performed to enhance heating capacity at low ambient temperatures. However, for outdoor temperature conditions below $-15^{\circ}C$, it is still difficult to obtain enough heating capacity above the rated value. In recent studies, the application of gas injection technique into a two-stage heat pump yielded noticeable heating performance improvement at low temperature conditions. In this study, the heating performance of a two-stage gas injection heat pump with a rated capacity of 3.5 kW was measured and analyzed by varying refrigerant charge amount and EEV opening at the standard heating condition. The heating performance of the two-stage gas injection heat pump was compared with that of a two-stage non-injection heat pump. The heating capacity and COP of the two-stage gas injection heat pump were improved by 2-10% at the optimal charging condition over those of the two-stage non-injection heat pump.

Study of Injection Molding Process of Shift Lever Using Injection Molding Analysis (사출성형해석을 통한 자동차 레버쉬프트의 사출공정에 관한 연구)

  • Park, Chul-Woo;Lee, Boo-Youn;Lee, Sang-Min
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.6
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    • pp.7-13
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    • 2015
  • The production processes were reviewed through the injection analysis of the shift lever as a core component of an auto lever installed in the automatic transmission of cars. The injection analysis was carried out for the shift lever and rod among the components in a shift lever module. The shift lever and rod are designed for injection molding with the insertion of a tube, a pin cable plate, and a steel rod for securing the strength of the product. The charging time, failure of injection molding, weld line, air trap, and deformation were reviewed according to this insert. Analyses on various gate positions were carried out for reviewing the cultivation and deformation of fiber around major components, such as the generation section of manipulation feeling and assembly section, so that optimal gate conditions might be reviewed and reflected in the mold design. Finally, we plan to compare the analysis results with the production of trial products.

An Experimental Study on the Heating Performance Characteristics of a Vapor Injection Heat Pump for Electric Vehicles (가스 인젝션을 적용한 전기자동차용 히트펌프의 난방성능 특성에 대한 실험적 연구)

  • Kim, Dongwoo;Jung, Jongho;Kim, Yongchan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.7
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    • pp.308-314
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    • 2014
  • A heat pump has been considered as a thermal management unit for electric vehicles, including the heating and cooling of the cabin. However, the heat pump shows performance degradation at low outdoor temperatures or high compressor speeds. In this study, a R-134a heat pump for an electric vehicle was designed to improve system efficiency, by applying vapor injection with an internal heat exchanger. The heating performance characteristics of the vapor injection heat pump were analyzed at various compressor speeds and outdoor temperatures. The vapor injection heat pump showed 13.3% COP improvement over the non-injection heat pump, when the heating capacity was fixed at 5.2 kW. In addition, the heating capacity of the vapor injection system increased by 9.6%, as compared to the non-injection system.

An Experimental Study on the Combustion and Emission Characteristics of the Early Injection in a Gasoline Direct Injection Engine Using Controlled Auto Ignition Combustion Method (CAI 연소 방법을 이용한 직분식 가솔린 엔진내의 조기 분사시 연소 및 배기 특성에 관한 실험적 연구)

  • Choi Young-Jong;Lee Ki-Hyung;Lee Chang-Hee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.5 s.248
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    • pp.457-464
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    • 2006
  • Controlled auto ignition (CAI) combustion, also known as HCCI (homogeneous charge compression ignition), offers the potential to simultaneously improve fuel economy and reduce emission. CAI-combustion was achieved in a single cylinder gasoline DI engine, with a cylinder running in a CAI mode. Standard components were used the camshafts which had been modified in order to restrict the gas exchange process. The effects of air-fuel ratio, residual EGR rate and injection timing such as early injection and late injection on the attainable CAI combustion region were investigated. The effect that injection timings on factor such as start of combustion, combustion duration and heat release rate was also investigated. From results early injection caused the mixture to ignite earlier and burn more quickly due to the exothermic reaction during the recompression and gave rise to good mixing of the fuel-air.

Active Control of Injection Mold Temperature using the Peltier Device (펠티어 소자를 이용한 사출 금형의 온도제어)

  • Cho, C.Y.;Shin, H.G.;Park, D.Y.;Hong, N.P.;Kim, B.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.183-186
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    • 2007
  • The injection molding process has high accuracy and good reproducibility that are essential for mass production at low cost. Conventional molding processes typically use the water-based mold heating and air cooling methods. However, in the nano injection molding processes, this semi-active mold temperature control results in the several defects such as air-flow mark, non-fill, sticking and tearing, etc. Therefore, in order to control temperature of the molds actively and improve the quality of the molded products, the novel nano injection molding system, which uses active heating and cooling method, has been introduced. By using the Peltier devices, the temperature of locally adiabatic molds can be controlled dramatically and the quality of the molded patterns can be improved.

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Bioventing 공법에서 TPH 제거에 대한 특징

  • Kim, Yeong-Am;Lee, Guk-Ui;Lee, Yong-Hui;Lee, Dong-Hwan;Kim, Dae-Hwan
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2005.11a
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    • pp.160-165
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    • 2005
  • Bioventing efficiency was compared in a continuous and an intermittent(6hr injection and 6hr rest) air injection mode. Two lab-scale columns which packed with 5kg of soil artificially contaminated by diesel oil were operated. The columns were maintained at the $25^{\circ}C{\pm}2.5$ in order to minimize the effect of exterior temperature variation. The flow rate of air injection mode were maintained constantly at the flow rate of 10ml/min. The moisture of the columns was stably maintained at $60{\sim}80%$ of field capacity. The nutrient compounds were added to make C : N : P ratio as 100 : 10 : 1. The continuous and intermittent injection modes showed 67.56% and 69.63%reduction of initial TPH concentration during 90 days, respectively. The loss of diesel oil by volatilization in the continuous and intermittent injection modes were about 5% and 1%, respectively.

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A Study on the Development of Icing by Injection of LPG in the Liquid Phase around Injector (I) (LPG 액상 분사 시 인젝터 주위의 Icing 현상에 관한 연구 (I))

  • 김우석;박정철;박심수;유재석;이종화
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.1
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    • pp.87-94
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    • 2003
  • Recently, LPLi(Liquied-Phase LPG injection) system is studied for the new stringent emission regulations. But , there are some problems to be solved such as injector tip icing and fuel leakage for LPLi system development. In this paper, the icing problem near injector tip which leads to difficulty of accurate A/F control was studied and reported. Icing of injector tip and port wall was observed at all the cases in this study regardless of injection duration and angle, air humidity change. The spray angle of LPLi was observed approximately two times wider than that of Gasoline injection. This makes the LPLi spray collide with intake port around injector tip. Temperature of the wetted area was decreased and icing of water vapor contained in intake air because of evaporation of the fuel film. The ice of the injector tip and port wall is also affected by the materials related to heat transfer.

A Study on the Flow Characteristics of an Intermittent Fuel Spray (간헐적인 연료분무의 유동특성에 관한 연구)

  • Kim, Won-Tae;Gang, Sin-Jae
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.9
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    • pp.1198-1206
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    • 1997
  • The flow characteristics of an intermittent fuel injection into a stationary ambient air were investigated using gasoline. The measurements were made by two-channel, air cooling type Phase Doppler Anemometer(PDA) system (DANTEC, 750 MW). And a pintle type injector of MPI (Multi-point Port Injection) system was utilized as a fuel injector. The PDA receiver optic was set up in a 60.deg. C forward scatter arrangement to obtain the optimum scattering signal of fuel droplets. The data were obtained by synchronizing PDA system with the fuel injection period, and the axial and radial velocity and turbulent components of fuel droplets were mainly measured for the analysis of temporal and spatial distribution depending upon the fuel injection pressures.

A Study on the Characteristics of NOx and another Emisson by Water Injection System for a Light-Duty Diesel Engine (물 분사 시스템에 의한 소형 디젤엔진의 NOx 및 그 외 배출물의 특성에 관한 연구)

  • Choi Jae-Sung;Nam Jeong-Gil
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.6
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    • pp.628-636
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    • 2005
  • In this paper. the effects of a WI(Water Injection) in the intake pipe for a 4-cylinder Dl(Direct Injection) diesel engine are investigated experimentally, The WI system was controlled by the duty cycle from the intake manifold's temperature and MAF(Manifold Air Flow) First. effect of EGR on NOx reduction was investigated. Then WI system was applied to reduce NOx As the results. we can make the NOx map and visualize the NOx results by variation of engine speed and engine load It was known that effect of WI system on NOx reduction without the EGR was better than the with EGR base engine except of low load and speed condition.