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LII/LIS 기법을 이용한 층류확산화염 매연입자의 정량화
정재우,이원남,한용택,김병수,이춘범,김덕진,이기형,Chung, J.W.,Lee, W.,Han, Y.T.,Kim, B.S.,Lee, C.B.,Kim, D.J.,Lee, K.H. 한국연소학회 2003 한국연소학회지 Vol.8 No.4
In this study, the quantification of soot particles in laminar diffusion flame with LII/LIS methods was performed. In these quantification, soot diameter, number density and volume fraction are included. For the quatification of soot particles, calibration tests are needed and the development of algorithm has to be performed. So, in this study, extinction and scattering test at co-flow burner were performed to acquire calibration data. And algorithm for LII/LIS simultaneous measurement for the quantification of soot were developed. The algorithm, which was the quantification of simultaneous photographing using one ICCD camera, to measure LII/LIS signal simultaneously, the best fitted light intensity and acquisition time was needed.
LII 및 LIS 계측기법을 이용한 디젤 연소실내 soot 계측
김덕진(Deokjin Kim),정재우(Jaewoo Chung),이춘범(Chunbeom Lee),서동규(Dongkyu Seo),이원남(Wonnam Lee) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
In-cylinder measurements of soot particle size and number density have been made using LII(Laser Induced Incandescence) and LIS(Laser Induced Scattering) measurement techniques in a direct injection diesel optical engine. LII/LIS measurement techniques and calibration techniques with laminar diffusion flame of co-flow burner are used to obtain quantitative information of soot particle. Two optical techniques were used simultaneously involving LII and LIS signal. One Intensified CCD camera was used to obtain 2D light signal images.
스월 유동이 직분식 디젤엔진 내의 Soot 분포에 미치는 영향에 관한 연구
이기형,정재우,이창식,박현종,Lee, Gi-Hyeong,Jeong, Jae-U,Lee, Chang-Sik,Park, Hyeon-Jong 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.3
Recently, many researches have been performed to improve performances of the combustion and emission in the D.I.Diesel engine. Especially reduction of the soot formation in tole combustion chamber is the essential to acquire the improvement of the emission performance. These emission of the diesel combustion is effected by the characteristics of air-fuel mixing. Thus, in this study, the distribution of soot in the diesel combustion is measured by LII(laser induced incandescence) and LIS(Laser induced scattering) method. From this experimental results, it is confirmed that the swirl flow intensified by SCV(swirl control valve) is effective on the reduction of soot in the combustion chamber.
Bae, Jae Kwan,Kim, Hyun-Woo,Accardo, Grazia,Kim, Ghun Sik,Ham, Hyung Chul,Jang, Seong-Cheol,Cho, Yong Soo,Yoon, Sung Pil Elsevier 2019 International journal of hydrogen energy Vol.44 No.47
<P><B>Abstract</B></P> <P>Molten carbonate fuel cells (MCFCs) are regarded as the closest fuel cell to commercialization due to their high capacity and energy efficiency. However, they are operated at a high temperature (620 °C or higher), where liquid electrolyte loss occurs during operation; hence, their lifetime is limited. For the long-term operation of MCFCs, it is essential to develop a novel method to replenish the electrolyte during operation. However, it is very difficult to directly inject the electrolyte, (Li<SUB>0.62</SUB>K<SUB>0.38</SUB>)<SUB>2</SUB>CO<SUB>3</SUB>, into each unit cell of the stack unless it is supplemented through liquid or gas phase at low temperature. It was verified whether LiI and KI, which have low melting points and high vapor pressures, could replenish the lost electrolyte in MCFCs. In this study, the LiI and KI injected into the unit cell in liquid phase showed a similar tendency to the Li/K carbonate electrolyte. This is because LiI and KI react with the CO<SUB>2</SUB>/O<SUB>2</SUB> gases supplied to the cathode during MCFC operation to form Li/K carbonate electrolytes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electrolyte precursors (LiI and KI) were selected by thermodynamic calculation. </LI> <LI> LiI and KI with low melting temp. are suitable for electrolyte replenishment. </LI> <LI> LiI and KI supplements are effective in ensuring stable performance for MCFCs. </LI> </UL> </P>
레이저 유도 백열법을 이용한 에틸렌 화염 배기에서의 Soot 입자 크기 계측에 관한 연구
전홍식(Hong Sik Chun),류훈철(Hoon Chul Ryu),박종일(Jong Il Park),엄규섭(Gyu Sub Eom),한재원(Jae Won Hahn),전광민(Kwang Min Chun) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5
Recently, particulate matter (PM) emission regulations are becoming more strict for diesel engines. There is increasing interest for measuring not only concentration, but also size of the particles. Laser -induced incandescence (LII) has emerged as a promising technique for measuring particle volume fraction and size. In this study, Simple time resolved LII (TIRE-LII) method was applied to the simulated exhaust of Ethylene diffusion flame as a preliminary test for measuring diesel exhaust PM emissions. The particle size results from LII technique were calibrated via field emission scanning electron microscope (FE-SEM) photograph. The inaccuracy of particle sizes between LII measurement and FE-SEM photograph was within 4.3%.
충류화염 유동속도 측정을 위한 modulated Lll 기법
이원남(Wonnam Lee),이정수(Jung Soo Lee),남연우(Youn Woo Nam) 한국연소학회 2006 한국연소학회지 Vol.11 No.3
The modulated LII technique has been suggested for the measurement of axial velocity profiles of laminar diffusion flames. The theoretical background is explained based on the blackbody radiation and LII signal. Experimentally, soot particles in ethylene diffusion flames are heated by a modulated Ar-ion laser beam. LII signals and their phase angles are measured using a lock-in amplifier at the different flame heights and the axial flow velocities are obtained from the measured phase angle delay informations. The measured velocities are similar to those from LDV measurements under the same operating conditions. The effects of laser power, LII signal wavelength, and modulation frequencies are not sensitive to the velocity measurement. However, the choice of an optical chopper blade type could affect the measurement result. The use of a 6/5 chopper blade showed the better result that is possibly due to the square shape of modulated laser beam. This study successfully demonstrated that axial flow velocities of laminar diffusion flames can be measured by a new technique utilizing LII signal, which does not need particle seeding unlikely to LDV or PIV techniques.
확산화염의 PAH LIF 신호 측정에 대한 LII 간섭
배승만(Seungman Bae),이상구(Sanggu Lee),안태국(Taekook Ahn),이원남(Wonnam Lee) 한국연소학회 2011 KOSCOSYMPOSIUM논문집 Vol.- No.42
The LII interference on the measurement of PAH LIF signal from a diffusion flame with 488 ㎚ wavelength Argon-ion laser excitation has been experimentally investigated. The signals measured in the region, where soot particles do not exist, can be interpreted as PAH LIF signals. However, in the region, where soot particles exist, the measured signals should be mostly considered as Mie scattering signals and/or LII signals depending on the measurement condition. In the region, where soot particles and PAH’s co-exist, the detection of PAH LIF signals would be difficult if not impossible with current measurement techniques.
아르곤이온 레이저를 이용한 확산화염 내 PAH의 LIF 신호 측정에 LII 신호가 미치는 영향
안태국(Taekook Ahn),배승만(Seungman Bae),이원남(Wonnam Lee),박선호(Sunho Park) 한국연소학회 2018 한국연소학회지 Vol.23 No.1
The effect of LII interference on the measurement of LIF signals from PAH in a diffusion flame has been investigated. Argon-ion laser at 488 nm was vertically or horizontally polarized, and irradiated to the centerline of the flame at varying flame height. Signals from PAH-rich regions measured at 515 nm were mostly LIF signals, however, signals from soot-rich regions were determined to be mixed with Mie scattering signals and/or LII signals. Signals measured 1 mm above the excitation height were mostly LII signals from soot particles. The results show that a quantitative determination of the LIF’s contribution to the measured signals would be difficult as long as the experimental setup described here is used for the regions where PAHs and soot particles exist together.
Scintillation Characterizations of Tin Doped Lithium Iodide Crystals at Room and Low Temperature
Khan, Sajid,Kim, H. J.,Kim, Y. D.,Lee, M. H. IEEE 2016 IEEE transactions on nuclear science Vol.63 No.2
<P>The crystals of 0.02%, 0.05%, 0.1%, and 0.5% Sn doped LiI are grown by the vertical Bridgman technique. The luminescence and scintillation properties of the grown crystals are investigated. X-ray excited emission spectrum of LiI (Sn) showed a broad emission band between 400-650 nm wavelength range at room temperature. Such emission is attributed to Sn2+ ion. Scintillation properties such as energy resolution, decay time profiles, and light yield are measured under 662 keV (137Cs) gamma-ray excitation at room temperature. A maximum light yield of 6000 +/- 600 ph/MeV is measured at room temperature. LiI (Sn) single crystals showed two exponential decay components under.-ray excitation. The dependence of scintillation properties on the temperature is also presented. Changes in the decay time and light yield are measured from 295 K down to 10 K. The light yield of LiI (Sn) at 50 K is found to be nine times higher than that at room temperature.</P>