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.

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.

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.

성층희박연소 운전조건에서 다단분사에 따른 분무유도식 직접분사 가솔린엔진의 연소특성

오희창(Heechang Oh),이민석(Minseok Lee),박정서(Jungseo Park),배충식(Choongsik Bae) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

In this study, the single cylinder engine experiment was carried out to investigate the effect of multiple injections on stratified combustion characteristics in a spray guided direct injection spark ignition engine. In the result of engine experiment with the single injection, indicated mean effective pressure was increased as injection timing was retarded to top dead center due to the increased effective work. However, the retardation of the injection timing was limited by the misfire occurrence resulted from the locally rich mixture generation under the high ambient pressure. Moreover, at the injection timing where the maximum IMEP was shown, HC and smoke emissions were increased due to the locally rich area of the stratified mixture. The multiple injection strategy was applied to enhance the local homogeneity of the stratified mixture. In the result of engine experiment with the double injection, IMEP and combustion efficiency were increased. As an index of combustion instability, COV of IMEP was decreased significantly with the double injection. This result implies that the local homogeneity of the stratified mixture was enhanced by the double injection. HC and CO emissions were decreased significantly with the double injection due to the enhanced local homogeneity of the stratified mixture. NOx emissions were increased due to the increased in-cylinder temperature resulted by more activated combustion. With the triple injection, the flammable injection timing window became narrower. Furthermore, IMEP and combustion efficiency were decreased. This is likely because the stratified mixture was formed on the upper position of the spark plug due to then shortened spray penetration.

커먼레일 타입 페에조 인젝터의 정밀 다단분사 제어를 위한 분사특성 연구

박희범 ( Hee Bum Park ),김형익 ( Hyung Ik Kim ),박상기 ( Sang Ki Park ),이기형 ( Ki Hyung Lee ) 한국분무공학회 2013 한국액체미립화학회지 Vol.18 No.4

In this study, injection quantity, rate and spray image of multiple injections which are important design parameters for a piezo type injector have been investigated. Interval of injections and a number of injections in multiple injection strategy has been controlled to verity interaction of each injection. Spray characteristics of multiple injections have been researched through optical process with a high speed camera in a high pressure chamber. In addition, a method of RMS(Root Mean Square) process has been used for comprehending the distribution of injection easily. As a result, in case of piezo type injec-tor, characteristics of injection quantity according to charging voltage and the difference of injection quantity between single and triple injection were confirmed. Also, injection rate for increasing injection duration was confirmed. And spray charac-teristics of multiple injections were improved; multiple injections were possible in a shorter time interval between each injec-tion. With this study, a possibilities of more accurate multiple injection control would be expected.

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.

다단분사가 초희박 GDI 엔진의 성능 및 배기에 미치는 영향

오진우(Jin Woo Oh),박철웅(Cheol Woong Park),김홍석(Hong Suk Kim),조규백(Gyu Baek Cho) 대한기계학회 2012 大韓機械學會論文集B Vol.36 No.2

현재 세계적으로 배출가스 규제 강화와 유가 상승으로 인해 가솔린엔진에서 배출되는 유해 배출가스 저감기술 및 연비향상 기술 개발이 절실히 요구되고 있다. 가솔린 직접분사(GDI; Gasoline direct injection) 기술은 가솔린 연료를 직접 연소실에 분사하여 정밀한 연소제어를 통해 매우 희박한 혼합기에서도 고효율의 연소가 가능하게 함으로써 연비저감과 고출력을 동시에 만족할 수 있는 효과적인 기술이다. 본 연구에서는 분무유도방식(spray-guided type)을 이용한 GDI 엔진을 개발하여 안정적인 희박연소를 구현하였다. 자주 사용되는 운전영역에서 연료분사시기의 TDC(Top dead center) 인근으로의 지각을 통하여 안정적인 희박연소를 구현하였으며, 다단분사를 적용하여 추가적인 연료소비율의 개선이 가능한 반면 탄화수소(THC)와 질소산화물(NOx)의 배출은 증가하고 CO의 배출은 감소되었다. Currently, in order to meet the reinforced emissions regulations for harmful exhaust gas including carbon dioxide (CO₂) as a greenhouse gas, technologies for reducing CO₂ emission and fuel consumption are being developed. Gasoline direct injection (GDI) systems have the advantage of improved fuel economy and higher power output than port fuel injection gasoline engine systems. The aim of this study is to examine the performance and emission characteristics of a lean burn GDI engine equipped with spray-guided-type combustion system. Stable lean combustion was achieved with a late fuel injection strategy under a constant operating condition. Further improvement in specific fuel consumption is possible with the introduction of multiple fuel injection strategies, which also increases hydrocarbon (HC) and nitrogen oxide (NOx) emissions and decreases carbon monoxide (CO) emission.

연료분무 및 연소 3 : 에조 인젝터의 다단분사에 따른 분무특성

박희범 ( Hee Bum Park ),김영진 ( Yung Jin Kim ),이기형 ( Ki Hyung Lee ) 한국액체미립화학회 2012 한국액체미립화학회 학술강연회 논문집 Vol.2012 No.-

Recently the trend of researching vehicle`s engine has focused on environmental aspects like an air pollution or high thermal efficiency. To meet strengthening emission regulations, a diesel engine has chosen due to its high efficiency. To reflect this trend a piezo type injector with common-rail was used for fast response and feasibility of multiple stage injection in short time instead of solenoid type injector. In this paper, spray image of multiple injections and injection rates are investigated which are important parameters of piezo type injector. The interval of injection has studied to identify interaction of each injection. With a high pressure visualization chamber, characteristics of multiple injection has researched. Also a method of RMS(Root Mean Square) process was conducted to find out the distribution of each injection easily. As a result various characteristics of piezo injector were identified

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.

바이오 디젤엔진의 다단분사 적용시 엔진 성능 및 배출가스 특성에 관한 연구

김형술(Hyung-Sul Kim),이강복(Gang-Bok Lee) 산업기술교육훈련학회 2011 산업기술연구논문지 (JITR) Vol.16 No.3

This paper described the effect of multiple injections on the engine performance and emission characteristics in a CRDI diesel engine using Bio diesel blended diesel fuel. In order to investigate the influence of multiple injections in a DI diesel engine, the injection timing was changed the main injection and pilot injection timings. The experimental apparatus consisted of DI diesel engine with four cylinders, multi-stage injection control system and exhaust emissions analyzer. The combustion and emission characteristics were analyzed for the main and pilot-main injection strategies. The combustion characteristics results show that the combustion pressure was smoothly near the top dead center due to the effect of pilot injection. Also, NOX emissions are decreased with pilot injection because the decrease of rate of heat release. However, the soot is increased at early pilot injection and main injection.