http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
촉매 연소기용 Static Mixer 의 내부 유동과 혼합 특성에 대한 수치적 연구
김종민(Chongmin Kim),홍동진(Dongjin Hong),김만영(Man Young Kim),이상민(Sang Min Lee),안국영(Kook Young Ahn),박윤범(Yun Beom Park) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11
In this study a numerical study to find the characteristics of the internal flow and mixing process has been conducted in a static mixer used in the system of catalytic combustor of the fuel cell power plant. After introducing the model description and final governing equations the present numerical approach is applied to the analysis of static mixer, which may have one or more helical elements inside the circular tube by changing such various parameters as incoming mass flow rates and the number of helical elements. The results show that although the static mixer is efficient in mixing fuel and air, more optimization processes are required to achieve the appropriate mixing characteristics in front of the honeycomb type catalytic combustor used in the MCFC power plant
A numerical study on the flow characteristics in the mixing region of the catalytic combustor
Dongjin Hong,Chongmin Kim,Man Young Kim,Sang Min Lee,Kook Young Ahn 대한기계학회 2007 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.21 No.11
Catalytic combustion is usually accomplished by a chemical reaction at the catalyst surface. Therefore, it is important that the fuel and air stream be well mixed and supplied uniformly. In this study, a perforated plate is used to enhance the mixing and flow uniformity for stable catalytic combustion. Also, a numerical simulation is performed to investigate the variation of flow characteristics according to various parameters. The results show that the uniformity of mixing and flow can be effectively improved for most of the cases by using a well-designed perforated plate.
25㎾ 급 MCFC용 촉매연소기 개발에 대한 실험적 연구
김종민(Chongmin Kim),홍동진(Dongjin Hong),이연화(Younwha Lee),김만영(Man Young Kim),조주형(Ju Hyeong Cho),김한석(Han-Seok Kim),안국영(Kook Young Ahn) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5
MCFC (molten carbonate fuel cell) power generation system is prime candidate for the utilization of fossil based fuels to generate ultra clean power with a high efficiency. In the MCFC power plant system, a combustor performs a role to supply high temperature mixture gases for cathode and heat for reformer by using the stack off-gas of the anode which includes a high concentration of H₂O and CO₂. Since a combustor needs to be operated in a very lean condition and to avoid excessive local heating, catalytic combustor is usually used. The catalytic combustion is accomplished by the catalytic chemical reaction between fuel and oxidizer at catalyst surface, different from conventional combustion. This experimental study presents the investigation on combustion characteristics of the model catalytic combustor(1㎾). Various effects on the performances of the catalytic combustor are observed, depending on the operating condition. Consequently, design point of combustor system is a fix on and try to scale up the catalyst combustor(25㎾).
5kW 급 MCFC 발전시스템 촉매연소기의 유동 및 연소 특성에 대한 수치적 연구
김종민(Chongmin Kim),이연화(Younwha Lee),김만영(Man Young Kim),김형곤(Hyung gon Kim),홍동진(Dongjin Hong),조주형(Ju Hyeong Cho),김한석(Han-Seok Kim),안국영(Kook Young Ahn) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
MCFC (molten carbonate fuel cell) power generation system is prime candidate for the utilization of fossil based fuels to generate ultra clean power with a high efficiency. In the MCFC power plant system, a combustor performs a role to supply high temperature mixture gases for cathode and heat for reformer by using the stack off-gas of the anode which includes a high concentration of H₂O and CO₂. Since a combustor needs to be operated in a very lean condition and to avoid excessive local heating, catalytic combustor is usually used. The catalytic combustion is accomplished by the catalytic chemical reaction between fuel and oxidizer at catalyst surface, different from conventional combustion. In this study, a mathematical model for the prediction of internal flow and catalytic combustion characteristics in the catalytic combustor adopted in the MCFC power plant system is suggested by using the numerical methods. The numerical simulation models are then implemented into the commercial CFD code. After verifying result by comparing with the experimental data and calibrated kinetic parameters of catalytic combustion reaction, a numerical simulation is performed to investigate the variation of flow and combustion characteristics by changing such various parameters as inlet configuration and inlet temperature. The result show that the catalytic combustion can be effectively improved for most of the case by using the perforated plate and subsequent stable catalytic combustion is expected.
홍동진(Dongjin Hong),김종민(Chongmin Kim),김만영(Man Young Kim) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.9
촉매 연소는 통상의 연소 방식과는 달리 촉매 표면에서 연료와 산화제의 화학 반응에 의한 연소 방식이다. 따라서 연소 영역 이전에 연료와 공기가 잘 혼합되어야 하며, 균일한 공급이 이루어져야 한다. 만약 불균일한 유동 분포가 발생하게 되면, 국부적인 고온 지역이 발생하게 되고 이는 촉매와 지지체에 손상을 초래하게 된다. 본 연구에서는 촉매 연소기의 혼합 및 유동 균일도를 향상시키기 위해 다공판을 사용하였으며, 다양한 파라메터의 변화에 따른 유동 특성의 변화를 조사하기 위해 수치적인 방법을 사용하였다. 각각의 조건하에서 촉매부의 입구에서 유동의 균일도를 조사하고 평가하였으며, 그 결과 적절히 설계된 다공판을 사용하였을 경우 대부분의 해석 조건에 대해 효과적인 균일도 향상을 나타냄을 확인할 수 있었다. A catalytic combustion is accomplished by the chemical reaction between fuel and oxidizer at the catalyst surface, different from conventional combustion. Therefore, it is important that the fuel and air stream are well mixed and supplied uniformly prior to the combustion region. If the flow is maldistributed, a hot spot may occur that can lead to subsequent catalyst and substrate damage. Therefore, in order to enhance the mixing and flow uniformity, in this study, the perforated plate is used. A numerical simulation is performed to investigate the variation of flow characteristics by changing various parameters. Under each condition, the uniformity of the flow stream at the entrance of the catalyst section is evaluated and compared. The results show that the uniformity can be effectively improved for most of the case by using the well-designed perforated plates.
김희정(Kim Heejeong),홍정민(Hong Chongmin) 질적연구학회 2009 질적연구 Vol.10 No.1
Purpose: The purpose of this study was to discover the body weight control process of women who have normal body weight. Methods: Six participants with normal body weight were recruited by theoretical sampling methods. The data were retrieved through in depth interview and participant observation. Collected data were analyzed through grounded theory approach of Strauss and Corbin (1998). Results: Eighty three concepts, thirty subcategories, and thirteen categories were deduced from the open coding process. The continuous weight control process of normal body weight women showed to be a process of 'Living within the frame that made by oneself', and its chronological process was including the phase of determination, propulsion, change, and acceptance. ‘Living within the frame that made by oneself’ had an active performance type and passive performance type. Conclusion: The results provided basic information for nursing intervention strategies depending on 'Living within the frame that made by oneself' process by each phase and different types.
Euro 2 기준 LNG-경유 혼소엔진의 배출가스 특성에 관한 연구
조규백(Gyu Baek Cho),김종민(Chongmin Kim),김동식(Dong Sik Kim),김홍석(Hong Suk Kim) 한국가스학회 2011 한국가스학회지 Vol.15 No.1
대형 디젤엔진은 주행거리가 길고 배기량이 크기 때문에 차량의 대수는 상대적으로 적지만 대기환경에 미치는 영향은 크다. 시내를 주행하는 시내버스의 경우 한일 월드컵을 계기로 CNG 버스로 전환되었다. 그러나 대형트럭과 장거리 시외버스의 경우 주행거리가 길고 CNG 충전소가 대도시의 시내버스 차고지 위주로 설치되어 있어 이용이 불가능하였다. 단열용기의 적용으로 천연가스를 압축상태가 아닌 액체 상태로 보관이 가능해져 주행거리가 긴 대형트럭이나 장거리 시외버스로의 적용이 가능해졌으며, 혼소엔진의 경우 LNG 충전이 어려운 지역에서는 디젤로 운행이 가능하다. 이와 같은 장점으로 인하여 석유 의존도를 크게 낮출 수 있어 에너지원의 다변화가 가능하며, 디젤차의 고질적인 단점으로 여겨왔던 매연 및 질소산화물뿐만 아니라 저탄소 연료를 사용함으로서 대표적인 온실가스중의 하나인 이산화탄소도 10%이상 저감할 수 있었다. Heavy duty diesel engine has relatively small portion of whole vehicles due to long drive distance and large engine displacement, but largely influences atmosphere environment. City buses changed to CNG (Compressed Natural Gas) bus with Korea-Japan Worldcup. Heavy duty truck and intercity bus, however, were impossible to use CNG because those kinds of vehicles had long drive distance and CNG station was installed mainly at the around of the bus garage of city. Insulation container storing the natural gas as a liquid makes heavy duty truck and intercity bus possible to use the natural gas. Drive using diesel is possible where is hard to recharge the gas. With LNG (Liquefied Natural Gas), the dependence on oil is largely decreased, PM (Particulate Matter) and NOx which is chronic disadvantage of diesel is remarkably reduced and finally CO2, the representative green house gas, is reduced over 10%.
선박용 고유황유에서 산화촉매 NO/NO₂ 전환 특성에 관한 연구
조규백(Gyu Baek Cho),김재희(Jaehee Kim),김종민(Chongmin Kim),윤천석(Cheon Seog Yoon),김홍석(Hong Suk Kim),김용진(Young Jin Kim) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
Hazardous emissions gas material from marine engine. In this study, the conversion characteristics of NO/NO₂, which is from the marine engine using high-sulfur fuel, is analyzed. For advancing the performance of SCR, oxidation catalyst technology is applied to the SCR, and the characteristics of Light-off temperature is calibrated according to materials of washcoat. Also, The calibration of conversion rate from samples is executed with variety of space velocities. Finally, the technology about NO/NO₂ conversion characteristics from diesel engine used by ship is secured, more over the possibility to apply the SCR to the marine engine is studied