• Title/Summary/Keyword: Air Injection

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An Experimental Study for Reducing the Exhaust Hydrocarbon Emission at SI Engine Using Timed Secondary Air Injection (2차 공기 분사에 의한 스파크 점화 가솔린 엔진의 배기 Hydrocarbon 저감에 관한 실험적 연구)

  • 심현성;김세준;정석호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.104-112
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    • 1999
  • An experimental study for reducing the exhaust hydrocarbon emission at spark ignition engine using timed secondary air injection is carried out . In this study, secondary air injection timings and durations are controlled to decrease the hydrocarbon emission and to increase exhaust gas temperature at cold and warm-up engine conditions. The hydrocarbon reduction rate and exhaust gas temperature are compared between timed secondary air injection and continuous air injection. The optimum secondary air injection timing for reducing the hydrocarbon emission is at the exhaust valve open timing. At some engine conditions , the hydrocarbon emissions are decreased to 10% of engine raw values and exhaust gas temperatures increase by 20$0^{\circ}C$ with times secondary air injection . Timed secondary air injection has more hydrocarbon reduction rate that continuous secondary air injection except some engine conditions.

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Lab-Scale Biosparging Study to Remediate Diesel-Contaminated Soil and Groundwater : the effect of air injection rate and pattern

  • 조수형;이시진;권순열;장순웅
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.462-466
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    • 2003
  • This study was conducted to examine the potential of biosparging process in removing diesel contaminated soil and groundwater. The experiment was carried out lab-scale biosparging reactor and the biodegradation rate of diesel was evaluated as function of air injection rate and pattern. When renter was operated as air injection rate of 1000$m\ell$/min and pulsed air injection(15min pulse, 15min downtime), DO concentration in the renter was higher than another operating condition. The evidence for biodegradation of diesel was the $O_2$ utilization and $CO_2$ product following the cessation of sparging. Especially, air injection rate of 2000$m\ell$/min and pulsed air injection(15min pulse, 15min downtime) enhanced the diesel biodegradation during the operating. After 120day, the biodegradation rate of diesel was decreased as the lack of carbon source.

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Permeation Characteristics of the Tubular Membrane Module Equipped wtih the Air Injection Nozzle Tube (공기주입 노즐관이 장착된 관형막의 투과특성)

  • Park, Mi Ja;Chung, Kun Yong
    • Membrane Journal
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    • v.27 no.1
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    • pp.43-52
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    • 2017
  • The air injection nozzle tube was inserted inside of the tubular membrane module to reduce membrane fouling and improve the permeate flux. The average pore size of membrane was $0.1\;{\mu}m$ and the yeast was used as a foulant. All of permeate experiments were started without air injection for the module equipped with the nozzle tube, then carried out continuously with air injection. Finally, the nozzle tube was removed from the module and the permeate was measured without air injection. The measured permeate fluxes were compared to examine the effect of air injection. The fluxes for air injection were consistently maintained or increased. The fluxes of no-air injection with the nozzle tube were greater than those of the empty tubular module. As operating pressure decreased to 0.4 bar, the flux enhancement of air injection based on no-nozzle case increased to 21%. Flux enhancements of air injection were above 30% as the gas/liquid two-phase flow was changed from the stratified-smooth to the intermittent pattern due to increase of gas flowrate.

Lab-Scale Air/Bio-Sparging Study to Remediate Diesel-Contaminated Soil and Groundwater : The Effect of Air Injection Rate and Pattern (디젤오염 토양 및 지하수 복원을 위한 공기주입정화법 실험실 연구 : 공기주입량과 공기주입방식의 영향)

  • Chang, Soon-Woong;Lee, Si-Jin;Cho, Su-Hyung;Yoon, Jun-Ki
    • Journal of Soil and Groundwater Environment
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    • v.11 no.4
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    • pp.10-17
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    • 2006
  • Laboratory-scale two-dimensional aquifer physical model studies were conducted to assess the effect of air injection rate and air injection pattern on the removal of disel contaminated soil and groundwater by air/bio-sparging. The experimental results were represented that the optimal conditions in this experiment were as air injection rate of 1,000 ml/min and pulsed air injection pattern(15 min on/off). The results of the TPH reduction, DO consumption and $CO_2$ production indicate the effective biodegradation evidence of diesel. Based on our results, The minimal $O_2$ supply and pulsed air injection pattern could effectively enhance the diesel removal and the pulsing air injection had effect on oxygenation in this system. Thus, the cost of operating air/bio-sparging system will be reduced if optimal air injection rate and pulsed air injection pattern are applied to remediate contaminants.

Evaluation of the Laboratory-Scale Cometabolic Air Sparging Process : Characterization of Indigeneous Microorganism on MTBE Degradation (실험실 규모 Cometabolic Air Sparging 공정 적용 특성 평가 : 토양 내 활성미생물 별 MTBE 분해특성)

  • An, Sang-Woo;Lee, Si-Jin;Chang, Soon-Woong
    • Journal of Soil and Groundwater Environment
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    • v.15 no.1
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    • pp.1-8
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    • 2010
  • Cometabolic air sparging (CAS) is a new and innovative technology that uses air sparging principles but attempts to optimize in situ contaminant degradation by adding a growth substrate to saturated zone. CAS relies on the degradation of the primary growth substrate and cometabolic substrate transformation in the saturated zone and in the vadose zone for volatilized contaminants. In this study, we have investigated to determine MTBE degradation pattern and microbial activity variation if using propane as a primary substrate at the condition of considering air injection rate and air injection pattern. Laboratory-scale two-dimentional aquifer physical model studies were used and the experimental results were represented that the optimal conditions were as air injection rate of 1,000 mL/min and pulsed air injection pattern (15 min on/off). Over 1,000 mL/min air injection rate and continuous air injection pattern was no affected to increase DO concentration. On the other hand, Injection of propane and propane-utilizing bacteria degraded MTBE partially. And also, injection of propane- and MTBE-utilizing bacteria effectively degraded MTBE and TBA production was observed.

An Experimental Study on the Improvement of Turbocharger Lag by Means of Air Injection in a Turbocharged Diesel Engine

  • Choi, Nag-Jung;Oh, Seong-Mo
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.7
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    • pp.951-962
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    • 2010
  • An experimental study was performed to investigate the improvement of response performance of a turbocharged diesel engine under the operating conditions of low speed and fast acceleration. In this study, the experiment for improving the low speed and acceleration performance is performed by means of injecting air into the intake manifold of compressor exit during the period of low speed and application of a fast acceleration from low speed. The effects of air injection into the intake manifold on the response performance were investigated at various applicant parameters such as air injection pressure, accelerating rate, accelerating time, engine speed and load. The experimental results show that air injection into the intake manifold at compressor exit is closely related to the improvement of turbocharger lag under low speed and accelerating conditions of a turbocharged diesel engine. During the rapid acceleration period, the air injection into the intake manifold of turbocharged diesel engine indicates the improvement of the combustion characteristics and gas pressure in the cylinder. At low speed range of the engine, the effect of air injection shows the improvement of the pressure distribution of turbocharger and combustion pressure during the period of gas exchange pressure.

Study on the cavitation and noise characteristics by air injection in three dimensional hydrofoil (3차원 수중익에서 공기분사에 의한 캐비테이션 및 소음특성 연구)

  • Seol, Hanshin;Jeong, Hongseok
    • The Journal of the Acoustical Society of Korea
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    • v.40 no.1
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    • pp.38-45
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    • 2021
  • In this study, changes in cavitation pattern and noise by air injection were investigated experimentally in a cavitation tunnel. Air injection system that can control the location and the amount of air was manufactured and installed in an elliptic wing that exhibits similar characteristics to those of a propeller blade. Various types of cavitation were simulated on the hydrofoil by adjusting the test conditions in the cavitation tunnel, and the changes in cavitation pattern and noise according to air injection were experimentally analyzed. It was shown that the noise characteristics varied depending on the position and the amount of air injection. This means that in order to apply the air injection technology to the propeller, it is necessary to optimize the air injection location and the amount of injection according to the cavitation characteristics.

Comparison of effectiveness of Aeration Modes on the Removal of Landfill Gases for Landfill Mining (폐기물매립지 굴착사업을 위한 가스치환시 공기공급방법의 효율성 비교)

  • 남궁완;박준석;김정대
    • Journal of Korea Soil Environment Society
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    • v.3 no.2
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    • pp.79-88
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    • 1998
  • The purpose of this study was to estimate the removal potential of landfill gases during landfill mining project. Air injection mode and landfill gas extraction mode were tested. A mode that air injected at one injection well and landfill gas extracted at another extraction well at the same time was also tested to compare. The flow rates of all modes were the same as 15$\textrm{km}^2$/min. Air injection mode was the most effective in removing $CH_4$. Air injection/extraction mode didn't improve the effectiveness of removing CH$_4$compared with air injection mode. Air injection mode were more advantageous than air injection/extraction mode in respect to energy consumption because that of air injection/extraction mode were doubled.

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Permeation Characteristics of the Tubular Membrane with Continuous Air Cleaning System (연속식 공기세정 관형막 투과특성)

  • Park, Mi Ja;Chung, Kun Yong
    • Membrane Journal
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    • v.23 no.2
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    • pp.185-188
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    • 2013
  • This study was carried out for microfiltration tubular membrane module equipped with self-designed air injection nozzle in order to determine the permeate flux due to the effect of membrane fouling reduction. The 0.1 wt% yeast particle solution was used as a feed solution and permeation tests were performed for the cases with and without air injection. Permeation fluxes were measured and analyzed to examine the effect of membrane fouling reduction. While the permeation flux without air injection decreased continuously, that with air injection was improved more than 30 percent than that of no air injection case.

The Effects of Air Injection in Compressor Exit on the Response Performance of a Turbocharged Diesel Engine under the Operating Conditions of Rapid Acceleration. (터보과급디젤기관의 급가속 운전시 압축기출구에의 공기분사가 응답성능에 미치는 영향)

  • 박상규;최낙정
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.6
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    • pp.110-119
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    • 2000
  • In this paper, an experimental study is carried out under the operating conditions of low speed and rapid acceleration in order to investigate and improve the response characteristics of a turbocharged diesel engine with radial turbine driven by exhaust gas. A rapid acceleration for investigating the response performance is applied to the fuel-pump rack of the engine from 0-10% to 0-40% in steps of 10%, and accelerating time of 1, 2 and 3 seconds is applied to the engine. Further experiment for improving the low speed torque and acceleration performance is also performed by means of injecting air into the inlet manifold at compressor exit during the period of low speed and application of a rapid acceleration. The effects of air injection on the response performance are represented at subjected engine speed with the changes of response performance factors such as air injection pressure, air injection period, accelerating rate, accelerating time and load. From the experimental results obtained throughout this study, it is shown that air injection into the inlet manifold at compressor exit is closely related to the improvement of low speed and acceleration performance of a turbocharged diesel engine.

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