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고분자전해질형 연료전지 유로 채널 기하에 따른 액적 분리현상 관찰
김보경(Bokyung Kim),민경덕(Kyungdoug Min) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
To investigate the characteristics of water droplet on the gas diffusion layer from both upper-view and side-view of flow channel, a rig test apparatus was designed and fabricated with Prism attached plate. This experimental device is used to simulate the single droplet growth and its transport process under PEM fuel cell operating condition with various channel height. The contact angle, hysteresis and diameter of water droplet of instable moment are measured and analyzed. Water droplets are removed easily by decreasing channel height and the tendency is analyzed numerically. It is expected that this study can provide the basic understanding of liquid water droplet behavior in gas flow channel and GDL interface during the PEM fuel cell operation with various channel height.
DISI 엔진에서의 엔진변수 변화에 따른 PM 배출특성 분석
임준원(Joonwon Lim),이경현(Kyeonghyeon Lee),민경덕(Kyungdoug Min) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11
DISI(Direct Injection Spark Ignition) engine is paid attention to be one of the solutions to improve thermal efficiency and fuel consumption. Strategy of DISI engine is to inject gasoline directly into the combustion chamber, and it allows to get the optimized condition for combustion on each driving mode. Consequently, DISI engine can achieve higher thermal efficiency and better fuel combustion than Port Fuel Injection engine. However due to the wall wetting phenomenon caused by high pressure injection directly into cylinder, there is a problem about excessive particulate matter emission. It is necessary to check the cause of Particulate Matter generation, because the regulation about the number of PM emission is under debate in many countries, and the numbering of PM is being one of the main concerns to the environmental issue. In this research, single cylinder DISI engine was used. Moreover the number and quantity of PM emission is measured on many conditions including changing injection timing and ignition timing with smokemeter and DMS 500 at the same time. By comparing both data, we could understand the effect of PM emission and assumed the cause of the emission.
노현우(Hyunwoo Noh),최승목(Seungmok Choi),민경덕(Kyungdoug Min) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11
In this research, the multi-spray-angle nozzle concept was introduced to reduce NOx and PM on Diesel Combustion as improving spray mixing by increasing spatial efficiency. The multi-spray-angle nozzle which has two spray rows was adopted to keep away from effect of plume to plume spray overlap. The single cylinder diesel engine that has piezo common rail injection system was utilized to investigate various types of nozzle. In this research, 9 holes in single-row nozzle as a reference and two of multi-row nozzles which have 10 holes in multi row were investigated. 10holes nozzles have different hole-diameter respectively. Nozzles were verified in various operating conditions that include injection timing, injection pressure, and SCV etc. In this research, rate of heat release was analyzed based on measured cylinder pressure.
마일드 하이브리드 차량에서 배터리 SoC에 따른 엔진의 작동효율 분석
조성우(Sungwoo Cho),정대봉(Daebong Jung),유성은(Seongeun Yu),민경덕(Kyungdoug Min) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5
This research focuses on the effects engine operating efficiency between battery SoC level in mild type hybrid electric vehicle. Although Hybrid electric power train system has been highlighted with potentials in low fuel consumption and exhaust gas emission, it is not easy matter to actualize these strengths. Hybrid electric power train system includes both engine system and electric system, so it is inevitable thing to optimize two different kinds of systems for ideal results. In this research, chassis driving test was conducted in different initial battery SoC condition. Based on experimental data, relation between engine efficiency and battery SoC was analyzed.
흡기압력과 산소농도에 따른 디젤연소의 천이에 관한 연구
이정우(Jeongwoo Lee),최승목(Seungmok Choi),신승협(SeungHyup Shin),민경덕(Kyungdoug Min) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
EURO 6 which is clarified to reduce NOx emission 55% more than EURO 5 regulation will be enforced in 2014. Therefore the reduction of NOx emission becomes more important. Especially, since there is a limitation that depends on after-treatment system to meet EURO 6 regulation, engine-out NOx emission must be diminished originally. Thus LTC concept which uses extremely high EGR rate to reduce oxygen concentration was developed to achieve low NOx and low PM simultaneously. However too much low oxygen concentration makes combustion detonate. Consequently, high boost pressure is used to stabilize diesel combustion when LTC is adjusted. But it is hard to explain that the relation between boost pressure and combustion stabilization. More strictly, it needs to study more about the relation between oxygen concentration and combustion stabilization. Therefore in this experiment, correlation about oxygen concentration as various boost pressure and diesel combustion regarding engine-out emissions is depicted. The results show that the limit oxygen concentration is changed as varying boost pressure.
조성우(Sungwoo Cho),유성은(Seongeun Yu),정대봉(Daebong Jung),민경덕(Kyungdoug Min) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11
This research focused on analysis of energy flow in parallel hybrid electric vehicle system. Hybrid Powertrain system includes much more equipment than conventional system, so it is not easy to pick up the point which causes low system efficiency. By calculating from chemical energy of fuel to kinetic energy delivered on wheel, however, energy flow chart can be diagramed. And conversion efficiency computed with this chart can help researchers to know which step caused more energy loss than expected. CAN is used as data acquisition method, as it is more brief way to get the driving parameter than any other method in chassis test situation. Most of all, CAN communicates real driving parameter which is used in ECU communication, it would be the most reasonable method in analyzing energy flow.
연소실 형상과 다중분사각 노즐이 디젤 연소 및 배기 특성에 미치는 영향에 관한 연구
신승협(Seunghyup Shin),노현우(Hyunwoo Noh),최승목(Seungmok Choi),이정우(Jeongwoo Lee),민경덕(Kyungdoug Min) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5
This paper presents characteristics of diesel combustion and emissions according to adoption of various combustion chamber shape and multi-spray-angle nozzle. Multi-spray-angle nozzle increases spray mixing by keep away from spray overlap. In this research, it is introduced different combustion chamber shapes. Combustion chamber shapes and injection timing affect emission characteristics due to change target area of spray in the combustion chamber. 7 holes in single row nozzle and 12 holes in double row nozzle were examined. To change combustion chamber shapes, single bowl piston as a reference and double bowl piston were used. Also, experiments were conducted according to different injection timing and injection pressure.
고 EGR 영역의 디젤연소에서 다단분사가 배기물질에 미치는 영향
이정우(Jeongwoo Lee),신승협(Seunghyup Shin),최승목(Seungmok Choi),민경덕(Kyungdoug Min) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11
Recently one of the main issues in diesel engine is reduction of emissions. Especially, NOx and PM are important because Euro 6 regulation which demands 55.6% NOx reduction is enforced in 2014. One of the effective ways to reduce engine-out NOx and PM emissions is a LTC method. LTC is implemented by high EGR rate to reduce oxygen concentration. Low oxygen concentration makes combustion temperature low and ignition delay much longer. So it suggests the possibility of reduction NOx and PM simultaneously. But because of low oxygen concentration, combustion efficiency is bad and CO and HC emissions are increasing sharply. To reduce the CO and HC emissions, many researches have been performed, especially about swirl motion. However there are a few papers about injection strategies on LTC to improve emission problem. So this paper focused on the effects of multiple injections on emissions when high EGR rate is applied. Experiments were done by sweeping the second injection timing form BTDC 46 CA to ATDC 10 CA. The result shows CO emission decrease drastically at some points with other emissions same level. So it can aid to maintain the stable combustion of LTC.