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선택적 촉매 환원법을 위한 외부 혼합형 이유체 노즐 개발에 대한 실험적 연구
박정근 ( J. K. Park ),이충원 ( C. W. Lee ) 한국분무공학회 2004 한국액체미립화학회지 Vol.9 No.2
N/A The effect of the working fluid flow conditions and nozzle geometry on the spray performance of a twin-fluid nozzle used in Selective Catalytic Reduction is investigated experimentally. The liquid pressure is varied in the range of 0.3atm to 1.5atm and the air pressure is varied from the 0.5atm to 3.0atm. relative position between liquid nozzle(internal nozzle) and air nozzle(external nozzle) tip changes from 1mm inside the air nozzle to 1mm outside the air nozzle. The orifice diameter of the air nozzle is varied with 5㎜, 6㎜ and 7㎜. Spray visualization is realized with CCD-Camera. SMD(Sauter Mean Diameter) and mean particle velocities are measured by PDPA(Phase Doppler Particle Analyzer) under various experimental conditions. The measuring point is 300㎜ away from the nozzle tip in the downstream spray. The experimental results are that spray angle is depended air flow rate because nozzle diameter, air pressure and nozzle tip relative positions are related air flow rate. SMD is depended air flow rate and water flow rate. Also, SMD is increased when water flow rate is bigger. SMD is decreased when Air flow rate is bigger.
박용철(Y.C. Park),지대영(D.Y. Chi),서경우(K.W. Seo),윤현기(H.G. Yoon),박정근(J.G. Park) 한국전산유체공학회 2011 한국전산유체공학회 학술대회논문집 Vol.2011 No.5
During a reactor normal operation, a primary coolant was designed to remove the fission reaction heat of the reactor. When one pump is failure and the other pump shall supply the cooling water to cool the reduced power, it is necessary to estimate how much flow will be supplied to cool the reactor. We carried a flow net work analysis for two parallel pumping system as based on the piping net work of the primary cooling system in HANARO. As result, it is estimated thai the flow of one pump increased than the rated flow of the pump below the cavitation critical flow.
김태섭(T.S Kim),박정근(J.K Park),백중현(J.H. Baek),이동인(D.I Lee) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
It is well known that two representative methods satisfy the condition of Euro4 regulation. The first method is the reduction of NOx in an engine operation by utilizing EGR and the elimination of high NOx concentraion. Second method, the conentraiton of PM produced by high efficiency combustion sufficiently meets the requirement of regulation. and NOx generated in this process can be removed by SCR system. While it has better fuel efficiency than the first method mentioned above. urea supply infrastructure is demanded. In this paper summarized the contents which attain the efficiency of the optimum target Euro4 based on Euro3 engine using design of experiment. This paper selected wider spray angle and changed bowl shape for optimize combustion. So, Injector sample had two types. Also Piston bowl spahe had two types. Then, it obtains low PM ami high NOx. The NOx concentration is belowed target point that is considered the reduction by SCR system. At last, it is satisfied for emission target.
반추위 혐기성 미생물(박테리아 , 프로토조아 및 곰팡이)이 세포벽 구성물질의 분해에 미치는 상대적 역할
신기준,이성실,하종규,박정근,케이제이쳉 한국동물자원과학회 2000 한국축산학회지 Vol.42 No.5
To study the relative contributions of microbial groups (bacteria, protozoa and fungi) in rumen fluids to the overall process of cell wall digestion in the rumen, representatives of these groups were selected by physical treatment, chemical treatment and physicochemical treatments of whole rumen fluids. Physical treatments were performed by centrifuge, filteration and autoclave based on their size and weight. Chemical treatments were also performed by the addition of antibiotics and chemicals to rumen fluids as follows; antibacterial agent[streptomycin sulfate, penicillin G potassium and chloramphenicol(0.010㎎/㎖l each)], antiprotozoan agent[copper sulfate(0.15㎎/㎖), sodium lauryl sulfate (0.010mglml) and dioctyl sulfossucinate sodium salts(0.200㎎/㎖}], and antifungal agent[cychloheximide (0.05㎎/㎖) and nystatin(200U/㎖)]. To evaluate the potential activity and relative contribution to degradation of cell walls by specific microbial groups, the following fractions were prepared: a positive system (whole ruminal fluid), a bacterial (B) system, a protozoan (P) system, a fungal (F) system and a negative system (cell free rumen fluid). To assess the interactions between specific microbial fractions mixed cultures (B+P, B+F, and P+F) were also assigned. Patterns of degradation due to the various treatments resulted in three distinct groups of data based on the degradation rate of cell wall material and on cell wall degrading enzyme activities. The order of degradation was Positive and F systems $gt; B system $gt; Negative and P systems. Therefore, fungal activity was responsible for most of the cell wall degradation. Cell wall degradation by the anaerobic bacterial fraction was significantly less than by the fungal fraction and the protozoan fraction failed to grow under the conditions used. In general, in the mixed culture systems the co-culture systems demonstrated a decrease in cellulolysis compared with the monoculture systems. When one microbial fraction was associated with another microbial fraction, two types of results were obtained. The protozoan fraction inhibited cellulolysis of cell wall material by both the bacterial and fungal fraction, while in the coculture between the bacterial fraction and fungal fraction, a synergistic interaction was detected.