Research on the reaction progress of thermodynamic combustion based on arc and jet plasma energies using experimental and analytical methods

김권세,최두석 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.4

Plasma energies are a promising technique to increase IC engine performance, expend lean burn flame area, reduce exhaust gas, and enhance engine power. In particular, SI engines using combustion process can obtain the positive air, fuel and ignition sources, and international research organizations are intensively conducting research on new combustion in order to increase the performance for IC engines regarding solution methods that could ensure more stable combustion energies. These authors were conducted on arc and jet plasma energies in order to improve the reaction progress of thermodynamic combustion, where the unburned process in chemical state was changed from plasma signal, density, flame, temperature, and velocity, through experiment and analysis at rarefied mixture values of air and fuel excess ration ( f ) from air and C 3 H 8 after transmitting with discharge energies based on arc and jet plasma sources. Experimental and analytical methods were transmitted as high 1.2 J energy, where the strength of plasma volume was discharged between positive and negative electrodes to arc plasma, and jet plasma was monitored from reaction progress results as transmitting as 2.03 J energy higher than arc energy in order to have characteristics of directivity. Experimental and analytical conditions were set equally for combustion mixture ratio, which was changed at rarefaction from initial pressure of 4 bar, plasma duration 0.0015 s, plasma plug gap 1 mm, and mass fraction ( f ) 1.0, 1.2, 1.4 and 1.6. Reaction progress results were noticeable in that jet plasma was influenced more by fast advantages to expend the laminar flame with various waves in an unburned process than arc plasma of combustion response time from thermal diffusion with transient temperature change, plasma volume energy, and jet plasma had more advantages for rarefied combustion state from various energies as changed mass fraction rates ( f = 1.0, 1.2, 1.4 and 1.6) by initial jet. Consequentially, density result is noticeable in that jet plasma was quickly changed by a chemical equilibrium of density higher than arc plasma energy.

Relationship between flame thickness and velocity based on thermodynamic three kernels in a constant volume combustion chamber

김권세,임석연,최문석,윤태준,강도경,최두석 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.5

The aim of this study is to analyze the relationship between the flame thicknesses and velocity based on thermodynamic three kernels, including spark, arc and jet plasma discharges in a constant volume combustion chamber (CVCC). As the research method, a CVCC designed to ensure 400 cm 3 of internal volume were developed by the authors to analyze the combustion characteristics. The compositions of combustion system include the spark plugs (conventional spark, arc and jet types), pressure sensor, temperature sensor, oxygen sensor, control circuit, hardware and high-speed camera. A pressure sensor for measuring the progressive combustion uses a type of Kistler 601CBA00250. It is verified that the discharge level of a jet plasma model is higher by about 3.8 kV then an arc plasma model and the combustion time is also faster than other plasma types. Moreover, in the signal analysis, the charging time in a jet plasma model starts to detect the signal from -0.11 ms to 0 ms and the charging voltage height is raised up to 40 kV due to being affected by stored energy of a capacitor. Consequently, the combustion performances of the arc and jet plasma discharges are noticeable in that flame thickness and velocity characteristics could be affected by ionized kernels in a CVCC. As the air-C 3 H 8 equivalence rates, the progressive combustion and reaction by the arc and jet plasma discharges are more improved than the conventional spark discharge in a rarefied condition.

예연소실 점화 플러그의 화염 분출구 직경에 따른 매립지가스의 연소 특성

김권세,전영철,최두석,Kim, Kwonse,Jeon, Yeong-Cheol,Choi, Doo-Seuk 중소기업융합학회 2021 융합정보논문지 Vol.11 No.7

본 연구는 LFG(Land Fill Gas)의 주성분인 메탄(CH₄) 60%와 이산화탄소(CO₂) 40%로 구성된 매립지가스를 활용하여 정적연소 환경에서 연소의 초기 불안정성을 해결할 수 있는 실험적인 연구결과를 제안하는 것이다. 실험조건은 공기과잉율 0.9~1.6, 초기연소를 위한 압축압력 3bar, 실험주변온도 25℃, 실험용 연료가스 메탄, 예연소실 화염 분출구 직경 2.5, 3.0, 3.5, 4.0, 4.5mm로 설정하였다. 실험결과 M3.0 모델에서 초기화염의 확산성이 매우 증가된 특성을 확인할 수 있으며, 이와 같은 증가의 특성은 공기 과잉률이 0.9, 1.0, 1.2에서 오리피스의 효과가 극도로 향상하게 되었다는 점을 알 수 있었다. 결과적으로, 본 실험을 통하여 M3.0으로 설계된 예연소실 화염 분출구 치수를 LFG에 적용할 경우 기존의 점화 플러그 특성 보다 부분적인 연소의 성능을 높일 수 있다는 점을 확인할 수 있었다. This research work is to suggest the experimental results capable of solving an initial unsuitability of combustion and environment in a constant volume combustion chamber by using LFG(Land Fill Gas) which consists of 40% CO₂ and 60% CH₄. The experimental condition is set as 0.9~1.6 of air-fuel ratio, 3bar of combustion pressure, 25℃ of room temperature, methane for using gas, and 2.5~4.5 of Pre-chamber hole sizes. As a result, it can be seen that diffusion of initial flame is significantly increased by M3.0 model comparing with other one. The reason for the characteristics is that orifice effect is extremely improved by 0.9, 1.0, and 1.2 of air-fuel ratio comparing with other one. Consequently, this experiment is shown that M3.0 model is partially capable of improving combustion performance than a conventional ignition plug in case of applying to LFG with Pre-chamber design.

Experimental study on ultrasonic signal measurement and longitudinal wave transfer in air-CH4 mixture space

김권세,최두석,임석연 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.9

This current work offers the experimental method which is capable of measuring the air-methane gas using L-wave by an ultrasound sensor in a constant volume chamber (CVC). For experimental method, a constant volume chamber is integrated with of a high-sensitive ultrasound sensor, a conventional ultrasound sensor, a non-resistance cable, a temperature sensor, a pressure sensor and two mounted zigs. The main conditions, for the experiment defined in this work, are composed of 2 bar of initial pressure, 296 K of temperature, air-CH 4mixture of gas fuel, 25 V of input voltage, 3 Hz of pulse rate and 0.2-2 of measurement distance (m) for two different ultrasonic sensors. The resonant frequency is set 67.6, 70.6, 73.6 and 76.6 kHz by adjusting wavelength inside the circuit system. It is shown that sensitivity in ethylene vinyl acetate matching layer (EVAM) type is remarkably increased comparing with the chemical wood matching layer (CWM) type. Moreover, in comparison to the conventional CWM type, the amplitude height of EVAM type shows 1.19 V at 1 st , 1.05 V at 2 nd , 0.63 V of 3 rd , 0.40 V at 4 th and 0.27 V at 5 th in CVC. With regards to the average percentage, the EVAM type is shown up to 116, 250, 270, 263 and 350 % for 1 st , 2 nd , 3 rd , 4 th and 5 th comparing with the conventional. Consequently, the voltage characteristics improved by EVAM type layer is demonstrated that energy transfer is higher than CWM type in CVC and efficiently led to increasing the ultrasonic sensitivity in an air-methane mixture.

금융지주회사제도의 본질과 도입효과

김권세 慶尙大學校 經營行政大學院 2001 最高管理者課程論文集 Vol.20 No.-

자동차 머플러내 가변밸브 토션스프링에 따른 소음 및 진동 특성에 관한 연구

김권세(Kwonse Kim),박충열(Chungyeol Park),이유종(Yoojong Lee),최두석(Dooseuk Choi) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5

고압가스를 가정한 챔버 내부의 질소공급에 따른 초음파의 종파 에너지에 관한 감쇠 신호 분석

김권세(Kwonse Kim),정인호(Inho Jung),임석연(Seokyeon Im),최두석(Dooseuk Choi),김홍주(Hongju Kim) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

피에조 세라믹과 매칭레이어와의 최적 공진주파수 관계에 대한 연구

김권세(Kim, Kwon-Se),최두석(Choi, Doo-Seuk),김영춘(Kim, Young-Choon),조재웅(Cho Jae-Ung) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.7

초음파 센서는 거리를 측정하는 센서이다. 초음파 센서의 피에조 세라믹과 매칭레이어 접착기술이 가장 핵 심이 되는 기술이다. 본 논문에서는 초음파를 공기 중으로 발진해 주는 매칭레이어에 대한 관계의 연구와 함께 피에 조 세라믹과 매칭레이어를 접착한 경우 변화될 수 있는 결과를 추출하여 제 2의 사용가능 주파수를 발견하는 것이 목적이다. 또한 실제 압전소자인 피에조 세라믹과 케미컬우드인 매칭레이어를 사용하여 실험하였다. 피에조 세라믹의 OD는 Φ50×3T 로 설계 되었으며 매칭레이어 OD는 λ=1/4인 Φ62×12t로 설계하였다. 가장 최적의 공진 주파수는 53 Khz에서 음향 임피던스 값을 나타냈다. 실험결과, 유연성을 가진 접착제 보다 고체에 가까운 접착제를 사용할 경 우에 많은 사용가능 주파수를 생성할 수 있는 결과를 얻을 수 있다. Ultrasonic transducer is the sensor which is measuring distance. Piezo ceramic of ultrasonic sensor and adhesive technique of matching layer are the most core techniques. With the study of relation on matching layer which takes off the ultrasonic wave into the air, this paper aims to find the second useful frequency as the results which can be changed are extracted in case piezo ceramic and matching layer are bonded. And the experiment is done with piezo ceramic as real piezoelectric element and matching layer of chemical wood. OD of piezo ceramic has designed by Φ50×3T and OD of matching layer is designed by Φ62×12t with λ=1/4. Acoustic impedance is generated at the most optimum resonant frequency of 53 Khz. As experimental result, more available frequency can be generated by using the adhesive close to solid than the flexible one.

배기압력이 배기가변밸브 면에 분포하는 압력과 속도에 관한 연구

김권세(Kim, Kwon-Se),최두석(Choi, Doo-Seuk) 한국산학기술학회 2014 한국산학기술학회논문지 Vol.15 No.4

최근 자동차에 대한 환경규제가 대폭 강화되고 있으며,배기시스템은 빼놓을 수 없는 연구과제 중 하나이다.본 연구 의 목적은 배기가변밸브의 압력 위치에 따라 최대와 최소에 대한 영향 분포를 규명하는 것이다.실험은 배기가변밸브가 열리 는 측면부에 카메라를 이용하여 실시간 각도를 확인하고 내부유량,압력,밸브 열림 각의 데이터를 추출하여 유동해석을 통한 배기가변밸브의 압력과 속도에 대하여 위치별 특성을 분석하였다.압력의 결과는 밸브의 최초 열림이 머플러 내부에 압력을 감소시키는 결과를 나타내었다.속도는 압력과 반대되는 결과를 나타내었으며,하단부의 빠른 속도로 인한 밸브의 떨림 현상 이 발생된 것으로 확인되었다.이 연구로부터 얻은 결론은 기관성능 향상을 위해서 속도의 위치가 하단부로 유인할 경우 밸브면의 압력 분포가 더욱 증가하여 최적의 배압조건을 만들 수 있는 결과를 얻을 수 있었다. Environmental emission of recent automobile is drastically enhanced that it is one of the obvious assignments of exhaust system. This study is a purpose to establish of influence distribution on maxima and minima through the location of pressure on exhaust variable valve. The experiment are checked with real angles using camera which exhaust variable valve is opened side of point. Data has extracted to opening angles with internal flow, pressure. Exhaust variable valve through the floating analysis was analyzed the characteristic of location point about pressure and velocity. The pressures indicated the reduced results internal pressure within muffler. The velocity indicated an opposite results and vibration state of valve was verified to be operated as high speed from lower section. The conclusion to obtain from this study was found out the result to make the optimum back pressure condition as more increasing pressure distribution on valve face if the velocity location attracted by bottom point in order to improve for engine performance.

수소저장소내 가스유량 공급의 조건에 따른 열전달 특성에 관한 연구

김권세(Kwonse Kim),박장우(Jangwoo Park),최준호(Junho Choi),이제욱(Jeuk Lee),김영일(Youngil Kim) 한국자동차공학회 2022 한국자동차공학회 지부 학술대회 논문집 Vol.2022 No.5