• Title, Summary, Keyword: Exhaust emissions

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Combustion Characteristics of Premixed Charge Compression Ignition Diesel Engine with EGR System (EGR율에 따른 예혼합 압축 착화 디젤 엔진의 연소 특성)

  • 이창식;이기형;김대식;허성근
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.2
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    • pp.66-72
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    • 2002
  • A premixed charge compression ignition engine is experimentally investigated for the reduction of NOx and smoke emissions from diesel engines. In this study, the premixed fuel is injected into the intake manifold to form homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentrations of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. But HC emission was increased with the increase of premixed ratio. Also, when EGR system was applied to the PCCI diesel engine, the effect of EGR rate on the combustion characteristics and the exhaust gas emissions was discussed.

An Experimental Study on Effects of EGR Rate upon Exhaust Emissions in Small High-Speed Diesel Engines (소형 고속 디젤기관의 배기 배출물에 미치는 배기 재순환율의 영향에 관한 실험적 연구)

  • 임재근;배명환;김종일
    • Journal of Advanced Marine Engineering and Technology
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    • v.16 no.4
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    • pp.60-77
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    • 1992
  • The effects of exhaust gas recirculation(EGR) on the characteristics of exhaust emissions and specific fuel consumption have been investigated using an eight-cylinder, four cycle, direct injection diesel engine operating at several loads and speeds. The experiments in this study are conducted on the fixed fuel injection timing of $38^{\circ}$ BTDC regardless of experimental conditions. In conclusion, it is found that $NO_{x}$ emission is markedly reduced with the drop of burnt gas temperature at high speeds and loads especially as the EGR rate increases, while the soot particulate rises with EGR rate and load at a given engine speed, especially high loads. The reduction of exhaust emissions within the Korea heavy duty diesel engine emission standards can be roughly achieved by the optimal EGR rate without degarding the specific fuel consumption, based on the correlations between exhaust emissions.

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Development of an Environmental Friendly Hybrid Power System and its Application to Agricultural Machines (친환경 하이브리드 동력 시스템 개발 및 농기계 응용)

  • Kim, Sangcheol;Hong, Youngki;Kim, Gookhwan
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.5
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    • pp.447-452
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    • 2015
  • A hybrid power system was developed for agricultural machines with a 20kW output capacity, and it was attached to a multi-purpose cultivator to improve the performance of the cultivator. The hybrid system combined heterogeneous sources: an internal-combustion engine and an electric power motor. In addition, a power splitter was developed to simplify the power transmission structure. The cultivator using a hybrid system was designed to have increased fuel efficiency and output power and reduced exhaust gas emissions, while maintaining the functions of existing cultivators. The fuel consumption for driving the cultivator in the hybrid engine vehicle (HEV) mode was 341g/kWh, which was 36% less than the consumption in the engine (ENG) mode for the same load. The maximum power take off output of the hybrid power system was 12.7kW, which was 38% more than the output of the internal-combustion engine. In the HEV mode, harmful exhaust gas emissions were reduced; i.e., CO emissions were reduced by 36~41% and NOx emissions were reduced by 27~51% compared to the corresponding emissions in the ENG mode. The hybrid power system improved the fuel efficiency and reduced exhaust gas emissions in agricultural machinery. The hybrid system's lower exhaust gas emissions have considerable advantages in closed work environments such as crop production facilities. Therefore, agricultural machinery with less exhaust gas emissions should be commercialized.

Effect on Characteristics of Exhaust Emissions by Using Emulsified Fuel in Diesel Engine (디젤기관에 있어서 에멀젼연료가 배기배출물 특성에 미치는 영향)

  • Cho, Sang-Gon;Hwang, Sang-Jin;Yoo, Dong-Hoon;Lim, Jae-Keun
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.1
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    • pp.44-50
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    • 2007
  • Diesel engines have high thermal efficiency, and they have less CO & HC emissions than another engines. while NOx & Soot emissions are very much. compared with exhaust emission standards. However, the limit level is more and more strengthened yearly due to the importance of environmental protection. So, the optimal countermeasures for the reduction of NOx & Soot emissions below limit level are required. Therefore. the author has investigated the effects of emulsified fuel on the characteristics of exhaust emissions. using an four-cycle, four-cylinder and direct injection diesel engine because the using of emulsified fuel among various methods for reducing NOx & Soot emissions is simple in installation low in cost and high in efficiency. The results of investigation according to various operating conditions are as follows : 1) Specific fuel consumption increase maximum 19.8% at low load. but is not affected at full load. 2) In case of emulsion ratio 25%, NOx emission decrease 32% at 75% load. 30% at full load. 3) In case of emulsion ratio 25%, Soot emission decrease 84% at 75% load, 59% at full load.

Durability Characteristics of an IDI Diesel Engine Using Biodiesel Fuel (바이오디젤유를 사용하는 간접분사식 디젤기관의 내구 특성)

  • Ryu, Kyun-Hyun;Oh, Young-Taig
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.6
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    • pp.120-127
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    • 2005
  • An IDI diesel engine used to agricultural tractors was fueled with $20\%$ biodiesel fuel(BDF 20) in excess of 300 hours. Engine dynamometer testing was completed at regularly scheduled intervals to monitor the engine performance and exhaust emissions. The engine performance and exhaust emissions were sampled at 1 hour interval for analysis. The combustion variation such as the combustion maximum pressure and the crank angle at this maximum pressure was not appeared during long-time dynamometer testing. Also, BSFC with BDF 20 resulted in lower than with diesel fuel. Since the biodiesel fuel used in this study includes oxygen of about $11\%$, it could influence the combustion process strongly. So, BDF 20 resulted in lower emissions of carbon monoxide, carbon dioxide, and smoke emissions without special increase of oxides of nitrogen than diesel fuel. It was concluded that there was no unusual deterioration of the engine, or any unusual change in exhaust emissions from using the BDF 20.

An Experimental Study on Reductions of Idle Emissions with the Syngas Assist in an SI Engine (합성가스를 이용한 SI 엔진의 공회전 유해 배기가스 저감에 관한 실험적 연구)

  • Kim, Chang-Gi;Kang, Kern-Young;Song, Chun-Sub;Cho, Young-Seok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.3
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    • pp.174-182
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    • 2007
  • Fuel reforming technology for the fuel cell vehicles could be applied to internal combustion engine for the reduction of engine out emissions. Since syngas which is reformed from fossil fuel has hydrogen as a major component, it has abilities to enhance the combustion characteristics with wide flammability and high speed flame propagation. In this study, syngas was added to a gasoline engine to improve combustion stability and exhaust emissions of idle state. Syngas fraction is varied to 0%, 50%, 100% with various ignition timing and excess air ratio. Combustion stability, exhaust emissions, fuel consumption and exhaust gas temperature were measured to investigate the effects of syngas addition on idle performance. Results showed that syngas has ability to widely extend lean operation limit and ignition retard range with dramatical reduction of engine out emissions.

Exhaust Emissions Characteristics of Bi-fuel CNG/LPG Passenger Cars (CNG/LPG Bi-fuel 승용차의 배출가스 특성)

  • Cho, Chong-Pyo;Lee, Young-Jae;Kim, Gang-Chul;Kwon, Oh-Seuk
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.2
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    • pp.142-147
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    • 2011
  • Compressed natural gas (CNG) is well known as one of the cleanest burning alternative fuels. Bi-fuel CNG vehicle can also run on gasoline or another fuel while dedicated natural gas vehicle is designed to run on natural gas only. Recently, increased attention has been focused on bi-fuel CNG/LPG taxi because of good fuel economy of CNG. A number of LPG taxis modified to CNG Bi-fuel vehicles are running in many cities. In this paper, the emissions characteristics of in-use passenger cars running on CNG and LPG were investigated. Chassis dynamometer test was used to measure exhaust emissions from an in-use fleet of 5 cars. Exhaust emissions were collected for CVS-75 driving mode. The test results showed that for CNG fuel mode, CO, $CO_2$ and NMHC emissions decreased to 9%, 12% and 14% respectively, and $CH_4$ and $NO_x$ emissions increased to 317% and 47% respectively.

Performance and Emission Characteristics of a Compression Ignition Engine Operated with LPG and Cetane Enhancing Additives (LPG/DTBP 혼합연료를 사용하는 압축착화 엔진의 부분부하 성능 및 배기특성에 관한 연구)

  • Lee, Seok-Hwan;Oh, Seung-Mook;Choi, Young;Kang, Kern-Yong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.6
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    • pp.105-113
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    • 2010
  • In this study, a feasibility test of liquid petroleum gas (LPG) compression ignition (CI) engine has been carried out to study the effectiveness of cetane enhancing additive: Di-tertiary-butyl peroxide (DTBP). Performance and emissions characteristics of a CI engine fuelled with DTBP blended LPG fuel were examined. Also, the effect of EGR (exhaust gas recirculation) on the combustion and emissions characteristics has been investigated. Results showed that stable engine operation over a wide range of the engine loads was possible. Exhaust emissions measurements showed that hydrocarbon were decreased with the blended fuel at enhancing cetane number. Furthermore, the combustion stability of LPG with a cetane number improver was equivalent to that of commercial Diesel fuel. Increasing the EGR rate leads to deteriorate the IMEP (indicated mean effective pressure) and increase the ignition delay. It was found that the exhaust emissions with the EGR resulted in a very large reduction in nitrogen oxides at the expense of higher THC and CO emissions. Considering the results of engine performance and exhaust emissions, LPG blended fuel of enhancing cetane number could be used as an alternative fuel for diesel in a CI engine.

Factor Analysis on Exhaust Gas Emissions of Small DI Diesel Engine (직접분사식 소형 디젤엔진의 배기배출물에 대한 인자분석적 고찰)

  • JANG, Se-Ho;KIM, Yeong-Sik
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.2
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    • pp.586-592
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    • 2017
  • This study analyzed the effect of four control factors, RPM, load, EGR rate and cooling water temperature on the exhaust emissions of the small DI diesel engine. The amount of NOx and smoke emissions were measured through experiments for three levels of four control factors according to orthogonal array table, and the effect of four factors on NOx and smoke emissions was analyzed quantitatively. The main results obtained in this study are summarized as follows: 1. RPM, load and EGR rate have a great influence on NOx and smoke emissions, and the effect of cooling water temperature is negligible. 2. As RPM and load increases NOx emission increases and decreases sharply as the EGR rate increases. 3. Smoke emission decreases or increases randomly according to RPM and load, but increases sharply in proportion to the EGR rate. 4. EGR rate has the greatest effect on NOx and smoke emissions by more than 60% of contribution to variance, especially in the case of NOx emission, EGR rate represents a significant result even under the confidence level of 99% on ANOVA.

An Experimental Study on Individual HC Emission Characteristics and Startability for Various Composition Ratio of LPG Fuel on LPLi Engine (LPLi엔진에서의 LPG 연료 조성비가 개별탄화수소 배출특성과 시동성에 미치는 영향에 대한 연구)

  • Choi, Seong-Won;Kwak, Ho-Chul;Myung, Cha-Lee;Park, Sim-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.3
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    • pp.234-241
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    • 2007
  • The regulations for hydrocarbon emission from vehicles have become much more stringent in recent years. These more stringent regulations request vehicle manufacturers to develop the advanced exhaust system for reducing exhaust emissions. The exhaust emissions has many sources in vehicle. In order to investigate the characteristics of hydrocarbon(HC) in the exhaust manifold, concentrations of individual HC species were measured in exhaust process. Using sampling valve, the light hydrocarbon emissions were captured in the exhaust manifold(catalyst before and after) and analyzed from LPLi engine exhaust manifold(catalyst before and after) using different fuel properties. Then exhaust samples were measured by gas chromatography(GC) and exhaust gas analyzer. Catalyst conversion efficiency for fuel properties of Butane 100% was better than Propane 100%. Start delay of LPLi engine was observed as increment of propane contents in LPG fuels.