2단분사조건에서 파일럿 분사량이 바이오디젤 연료의 연소 및 배기 배출물 특성에 미치는 영향

이형민 한국마린엔지니어링학회 2019 한국마린엔지니어링학회지 Vol.43 No.7

The purpose of this research is to analyze the influence of pilot injection quantity on the combustion and exhaust emission characteristics of biodiesel fuel under two-stage injection conditions: pilot injection and main injection. The combustion visualization test of the main injection was also carried out on the amount of the pilot injection. Analysis of the combustion and exhaust emission characteristics of biodiesel fuel according to the pilot injection quantity and combustion visualization was performed in a common rail single cylinder diesel engine, which can be visualized. The total injection quantity of biodiesel fuel was 10 mg/stroke, and the main injection amount was adjusted according to pilot injection quantity. The increase in pilot injection quantity caused a cylinder wall surface or piston wall wetting increment, thereby reducing the combustion performance of the main injection. As a result, the in-cylinder pressure, rate of heat release, indicated mean effect pressure, and torque decreased. As the pilot injection amount increased, carbon monoxide and hydrocarbons tended to increase while nitrogen oxides decreased. As the pilot injection quantity increased through combustion visualization, the ignition delay period during the main injection became shorter and appears to be similar to diffusion combustion rather than premixed combustion in the initial combustion. 본 연구의 목적은 파일럿 분사와 주 분사로 이루어지는 2단분사조건에서 파일럿 분사량이 바이오디젤 연료의 연소및 배기 배출물 특성에 미치는 영향을 분석하는 것이다. 또한, 파일럿 분사량에 따라 주 분사의 연소 가시화 시험도 수행되었다. 파일럿 분사량에 따라 바이오디젤 연료의 연소 및 배기 배출물 특성 분석, 연소 가시화는 가시화가 가능한 커먼레일단기통 디젤엔진에서 수행되었다. 바이오디젤 연료의 총 분사량은 10mg/stroke이며, 파일럿 분사량에 따라 주 분사량도 조절되었다. 파일럿 분사량이 증가할수록 실린더 벽면 또는 피스톤 적심을 증가시킬 뿐만 아니라 주 분사의 연소 성능을 저감시켜 실린더 내부 압력, 열발생율, 도시평균유효압력 및 토크가 떨어지는 결과를 보였다. 파일럿 분사량이 증가할수록 일산화탄소 및 탄화수소는 증가한 반면, 질소산화물은 감소하는 결과로 나타났다. 연소가시화를 통해 파일럿 분사량이 증가할수록 주 분사 시 점화지연기간은 짧아지며, 초기 연소 시 예혼합 연소 보다는 확산연소에 가까운 형태로 나타났다.

DME 직접분사식 압축착화 엔진에서 파일럿 분사의 영향

윤현숙(Hyeonsook Yoon),배충식(Chongsik Bae) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The dimethyl-ether (DME) combustion with pilot injection was investigated in a single cylinder direct injection diesel engine equipped with the common-rail injection system. Combustion performance and emissions were tested with dimethyl-ether. The main injection timing was at the top dead center, which were the best timings for maximum power output. The total injected fuel mass was fixed 22㎣ per cycle at 800 rpm. The fuel quantity and the injection timing of the pilot injection were varied from 8 to 20% of the total injected mass and from 50 to 10 crank angle degree before the main injection timing, respectively. The ignition delay decreased with the pilot injection. The indicated mean effective pressure increased when dimethyl-ether was pilot-injected at 20 crank angle degree before the main injection timing. DME showed reduction in emissions, such as particulate, hydrocarbon, carbon monoxide and nitric oxides. The hydrocarbon and the carbon monoxide emissions were increased when the pilot injection timing was advanced. The nitric oxide emission was increased by 14% with 8% of pilot injection. Bigger amount of DME pilot-injection decreased nitric oxide emission.

다단분사를 사용한 경량 DME 엔진의 연소제어에 관한 연구

정수진(Soo-Jin Jeong),오세두(Se-Doo Oh),박정권(Jeong-Kwon Park) 한국자동차공학회 2012 한국자동차공학회 부문종합 학술대회 Vol.2012 No.5

Dimethyl-ether(DME) is one of the most promising alternative fuels for IC engines. In this study, the compression ignition combustion fueled with dimethyl-ether was investigated. Three-point split injection strategy was applied and evaluated its availability and performance in terms of emission(CO, HC, NOx, PM), fuel economy and power. Experiments were carried out in 4-cylinder 2.9 liter direct-injection diesel engine equipped with common-rail injection system, and the engine performance and emission characteristics were tested the various pre and pilot injection timings and quantities. Experiments were performed under the engine condition ranging from 1200rpm, 2bar to 3000rpm,4 bar. From the results of this study, three-point split injection strategy showed the possibility to overcome the disadvantages of DME engine such as high NOx and HC emissions due to long injection duration for attaining diesel equilibrium performance. By optimizing pre and pilot injection timing and quantities NOx emission could be reduced by maximum 68.5% for low speed and load conditions. Additional NOx reduction of could be obtain by retarding main injection timing. Torque could be improved by reducing injection dwell timing between pilot and main injection. In the range of medium and high load and speed conditions, main injection timing was retarded for reducing NOx emission with sacrificing torque. However, this torque reduction could be compensated by reducing pilot injection quantity and increasing the quantity of main injection.

직접분사식 단기통 디젤엔진에서 다단분사에 따른 연소 및 배기특성

허정윤(Jeong Yun Heo),차준표(Junepyo Cha),윤승현(Seung Hyun Yoon),이창식(Chang Sik Lee) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

The purpose of this work is an experimental investigation combustion and emission characteristics in DI diesel engine applied multiple injection strategy. In order to analyze the effect of multiple injection, single-cylinder DI diesel engine was operated under electrically controlled fuel injection system. In this study, multiple injections were injected as two types of multiple injection that were defined as the pilot injection and the post injection. The pilot injection and the post injection was injected 30% of total fuel injections mass quantity. The results of multiple injection were compared to those of single injection and each multiple injection types. To investigate for a low speed engine and middle range load, the experimental conditions were conducted under a fixed engine speed and constant stoichiometric ratio condition. The combustion results show that each multiple injections decreases peak heat release rates but increases indicated mean effective pressure. The emissions results that pilot injection increases emissions but post injection reduces NO<SUB>x</SUB>, HC and CO emissions.

다단분사를 적용한 경량 DME 트럭의 연구 및 개발

정수진(Soo-Jin Jeong),오세두(Se-Doo Oh),박정권(Jung-Kwon Park) 한국자동차공학회 2012 한국자동차공학회 지부 학술대회 논문집 Vol.2012 No.10

Dimethyl-ether(DME) is one of the most promising alternative fuels for ICengines. In this study, the compression ignition combustion fulled with dimethyl-ether was investigated. Three-point split injection strategy was applied and evaluated its availability and performance in terms of emission(CO, HC, NOx, PM), fuel economy and power. Experiments were carried out in 4-cylinder 2.9 liter direct-injection diesel engine equipped with common-rail injection system, and the engine performance and emission characteristics were tested the various pre and pilot injection timings and quantities. Experiments were performed under the engine condition ranging from 1200rpm, 2bar to 3000rpm,4 bar. From the results of this study, three-point split injection strategy showed the possibility to overcome the disadvantages of DME engine such as high NOx and HC emissions due to long injection duration for attaining diesel equilibrium performance. By optimizing pre and pilot injection timing and quantities NOx emission could be reduced by maximum 74% for low speed and load conditions. Additional NOx reduction of maximum 40% could be obtain by retarding main injection timing. Torque could be improved by reducing injection dwell timing between pilot and main injection. In the range of medium and high load and speed conditions, main injection timing was retarded for reducing NOx emission with sacrificing torque. However, this torque reduction could be compensated by reducing pilot injection quantity and increasing the quantity of main injection. Also, The DME vehicle was developed in this study, 120 km/h can drive to the stable, and calculated in accordance with the carbon-balance method of fuel consumptions is 5.7 km/L.

승용디젤엔진의 파일럿 분사가 피스톤 온도 상승 및 카본 퇴적에 미치는 영향 해석

김성준(Sung Jun Kim),이제형(Je-Hyuung Lee) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

To investigate the temperature increase and carbon deposit in the piston caused by applying pilot injection at high engine speed and high load, the spray behavior and combustion process in a HSDI Diesel engine were numerically analyzed using KIVA-3V. The combustion analysis was carried out varying injection conditions and injection system. The results show that as the pilot injection timing advances the early injected part of the pilot spray spreads close to the piston crown and stretches to the crevice area, and then the pilot spray bums over the piston surface. That pilot flame may cause the increase of piston temperature and carbon deposit. In case of the increase of the nozzle hole number and the decrease of the nozzle diameter, the penetration of the pilot spray decreases and most of pilot spray bums within the piston bowl. The analyzed results show a good agreement with the experiment.

포스터 전시회 : 다단분사를 적용한 2.9리터급 DME 엔진의 배기특성에 관한 연구

박정권 ( Jung Kwon Park ),김현철 ( Hyun Chul Kim ) 한국액체미립화학회 2013 한국액체미립화학회 학술강연회 논문집 Vol.2013 No.-

Dimethyl-ether(DME) is one of the most promising alternative fuels for IC engines. In this study, the compression ignition combustion fueled with dimethyl-ether was investigated. Three-point split injection strategy was applied and evaluated its availability and performance in terms of emission, fuel economy and power. Experiments were carried out in 4-cylinder 2.9 liter direct-injection diesel engine equipped with common-rail injection system, and the engine performance and emission characteristics were tested the various pre and pilot injection timings and quantities. Experiments were performed under the engine condition ranging from 1200rpm, 2bar to 3000rpm,4 bar. From the results of this study, three-point split injection strategy showed the possibility to overcome the disadvantages of DME engine such as high NOx and HC emissions due to long injection duration for attaining diesel equilibrium performance. By optimizing pre and pilot injection timing and quantities NOx emission could be reduced by maximum 74% for low speed and load conditions. Additional NOx reduction of maximum 40% could be obtain by retarding main injection timing. Torque could be improved by reducing injection dwell timing between pilot and main injection. In the range of medium and high load and speed conditions, main injection timing was retarded for reducing NOx emission with sacrificing torque.

승용 디젤 CRDI 엔진의 다단 분사가 연소 및 배기 특성에 미치는 영향

노현구(Hyun Gu Roh),이창식(Chang Sik Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper described the effect of the multiple injection on the stability of idle-operating and emission characteristics in a common rail direct injection diesel engine at various operating conditions. In order to investigate the influence of multiple injections in a diesel engine, the fuel injection timing was varied two pilot injections and one main injection at various conditions. The experimental apparatus is consisted of DI diesel engine with 4 cylinders, EC dynamometer, multi-stage injection control system, and exhaust emissions analyzer. The combustion pressure was measured using a piezoelectric pressure sensor installed the hole of glow plug. Detection of the crank angle of rotating engine was used for the crankshaft position sensor of the magnetic inductive type installed. The exhaust emissions from the engine were measured by using transmitted light type soot measuring instrument and NOx, HC and CO analyzer. The operating point was analyzed for the main, pilot-main, pilot-pilot-main strategy were tested. It is revealed that the combustion pressure was smoothly near the TDC and the coefficient of variations is reduced due to the effect of pilot injection. Also, NOx emissions are dramatically decreased with pilot injection because the rate of heat release. However Soot is increased at early pilot injection at main injection.

승용 디젤 CRDI 엔진의 다단 분사 및 분사압력이 연소 및 배기 특성에 미치는 영향

노현구(Hyungu Roh),전학식(Haksik Jeon),이창식(Changsik Lee) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper describes the effect of the multiple injection and injection pressure on the combustion and emission characteristics in a CRDI diesel engine at various operating conditions. In order to investigate the influence of multiple injections and injection pressure in a diesel engine, the fuel injection timing was varied double pilot injections and main injection at TDC. The experimental apparatus is consisted of DI diesel engine with 4 cylinders, EC dynamometer, multi-stage injection and injection pressure control system, and exhaust emissions analyzer. The combustion and emission characteristics are investigated of various injection strategies such as analyzed for the main, one pilot-main, double pilot-main strategy. The results showed that the average of peak combustion pressure is increased with the increase of injection pressure. Also, double pilot injection has a great effect on reducing NOx emissions because the decrease of peak heat release rates. However soot is increased at the double pilot injection compared to single injection. Based on this result, it showed that the combustion and emission characteristics can be improved as the pilot injection is retarded.

바이오디젤-CNG 혼소엔진에서 파일럿 분사량이 연소 및 배기 특성에 미치는 영향

유경현 ( Kyunghyun Ryu ) 한국액체미립화학회 2016 한국액체미립화학회지 Vol.21 No.2

The effect of pilot injection quantity on the combustion and emissions characteristics of a compression ignition engine with a biodiesel-compressed natural gas (CNG) dual fuel combustion (DFC) system is studied in this work. Biodiesel is used as a pilot injection fuel to ignite the main fuel, CNG of DFC. The pilot injection quantity is controlled to investigate the characteristics of combustion and exhaust emissions in a single cylinder diesel engine. The injection pressure and injection timing of pilot fuel are maintained at approximately 120 MPa and BTDC 17 crank angle, respectively. Results show that the indicated mean effective pressure (IMEP) of biodiesel-CNG DFC mode is similar to that of diesel-CNG DFC mode at all load conditions. Combustion stability of biodiesel-CNG DFC mode decreased with increase of engine load, but no notable trend of cycle-to-cycle variations with increase of pilot injection quantity is discovered. The combustion of biodiesel-CNG begins at a retarded crank angle compared to that of diesel-CNG at low load, but it is advanced at high loads. Smoke and NOx of biodiesel-CNG are simultaneously increased with the increase of pilot fuel quantity. Compared to the diesel-CNG DFC, however, smoke and NOx emissions are slightly reduced over all operating conditions. Biodiesel-CNG DFC yields higher CO2 emissions compared to diesel-CNG DFC over all engine conditions. CO and HC emissions for biodiesel-CNG DFC is decreased with the increase of pilot injection quantity.