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저공해 버너에서의 운전조건에 따른 미분탄 분배특성에 관한 수치해석 연구
윤성환(Sung Hwan Yoon),박정(Jeong Park),권오붕(Oh Boong Kwon),박호영(Ho Young Park),서상일(Sang Il Seo) 대한기계학회 2011 大韓機械學會論文集B Vol.35 No.5
국내에서 널리 사용되는 500 MW급 미분탄 화력발전에서 2개의 PM (pollution minimum) 버너의 최적 운전 범위를 확인하기 위하여 DPM (discrete phase model)을 활용하여 수치계산을 수행하였다. 본 연구는 저가의 아역청탄의 활용 증진을 위하여 다양한 조건에서 탄 종별로 연구를 수행하는데 그 목적이 있다. 탄 종별로 미분탄의 질량 유량, 1차 공기의 질량 유량, 그리고 미분탄의 입자 크기 분포를 달리하여 공기/석탄의 분배비의 영향을 조사하였다. 이러한 매개변수에 관하여 PM 버너에서의 공기/석탄의 분배비의 최적운전조건을 도출하고 이에 대해 논의하고자 한다. We performed numerical simulation using a DPM (discrete phase model) to identify the optimal operation ranges in two representative PM burners widely used in domestic 500-MW pulverized coal-fired power plants. Recently there has been an increased utilization of low-cost coals such as sub-bituminous coal. We investigate the effects of coal blends on the distribution ratio of coal to air by varying the mass flow rates of pulverized coal and primary air and the particle size. We present and discuss optimal conditions for the distribution ratio of coal to air in PM burners.
층류제트 부상화염에서 열손실에 의한 자기진동에 관한 연구
윤성환(Sung Hwan Yoon),박정(Jeong Park),권오붕(Oh Boong Kwon),김정수(Jeong Soo Kim),배대석(Dae Seok Bae),윤진한(Jin Han Yun),길상인(San in Keel) 대한기계학회 2011 大韓機械學會論文集B Vol.35 No.3
질소 희석된 프로판 부상화염에서 열손실에 의한 자기진동을 기초로 화염안정화선도를 도출하기 위하여 노즐직경 0.3 ㎜, 1.0 ㎜에서 실험적 연구를 수행하였다. 예혼합화염에서 확산화염으로의 전도 열손실에 의한 자기진동 및 매연 복사에 의한 자기진동을 관찰하였다. 0.1 ㎐보다 낮은 주파수 성향을 띄는 열손실에 의한 자기진동은 제안된 메커니즘에 의해 잘 묘사되었고 반면 매연복사에 의한 자기진동은 O(0.1 ㎐)의 주파수 범위를 나타내었으며 제안된 메커니즘은 항온항습실 실험을 통해 입증하였다. 질소 희석된 프로판 부상화염에서 관찰된 열손실에 의한 자기진동의 특성화는 관련된 변수 및 스트라훌 수에 의해 잘 묘사되었다. We experimentally investigated lifted propane jet flames diluted with nitrogen to obtain flame-stability maps based on heat-loss-induced self-excitation. We found that heat-loss-induced self-excitations are caused by conductive heat loss from premixed flame branches to trailing diffusion flames as well as soot radiation. The conductive-heat-loss-induced self-excitation at frequencies less than 0.1 ㎐ is explained well by a suggested mechanism, whereas the oscillation of the soot region induces a self-excitation of lift-off height of the order of 0.1 ㎐. The suggested mechanism is also verified from additive experiments in a room at constant temperature and humidity. The heat-loss-induced self-excitation is explained by the Strouhal numbers as a function of the relevant parameters.
석유수지 비중차를 이용한 고무아스팔트 도막-시트 복합방수의 부착성능 비교 연구
윤성환 ( Yoon Sung Hwan ),박완구 ( Park Wan Goo ),김동범 ( Kim Dong Bum ),박진상 ( Park Jin Sang ),오상근 ( Oh Sang Keun ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.2
The combined waterproofing technique, which forms the waterproofing layer of two or more substances, is characterized by forming a waterproof layer, which is characterized by the formation of waterproof layers and the thickness of the waterproofing layer is inherently formed. In this study, it is intended to verify the integrity of the material through the manufacture of materials for special purpose waterproofing methods, primarily for the manufacture of composite waterproofing materials and composite waterproofing methods using cement materials and materials.
원저 : 제주 지역 돼지 생식기 호흡기 증후군의 혈청학적 조사
윤성환 ( Sung Hwan Yoon ),손성원 ( Seong Won Sohn ),장원우 ( Won Woo Jang ),김성환 ( Seong Hwan Kim ),장소영 ( So Young Jang ),지영흔 ( Young Heum Jee ),김재훈 ( Jae Hoon Kim ),임윤규 ( Yoon Kyu Lim ) 한국수의공중보건학회 2010 예방수의학회지 Vol.34 No.4
Porcine reproductive and respiratory syndrome (PRRS) virus causes not only breeding disorder such as abortion, stillbirth and premature birth to pregnant sows but economic damage like high estrous return and low delivery rate. The presented study was conducted to confirm seroprevalence of PRRS in Jeju herds. PRRS positive rate was examined with pig serum from hog farms located in Jeju. Serum samples were extracted from the 11 of sow farms and 10 of hog farms, The groups were divided into 20, 40, 60, 80, 100 and older than 120 days of age and pregnant sows in hog farms. Anti-PRRSV antibody titers in sera were analyzed by ELISA. All the breeding farms and hog farms (10/10) showed PRRS positive except one breeding farm (1/11). Serological patterns determined by ELISA did not show any difference regardless of whether pigs were vaccinated or not. Nevertheless, the farms unvaccinated pigs displayed low productivity in terms of piglet loss rate and prolonged period of shipment. Therefore, vaccination against PRRSV appears to be a crucial factor in sanitary management of hog farms. Taken together, since PRRSV was spread widely in Jeju already, stabilization of sows by PRRS vaccination after adapting PRRSV free sow by all-in-all-out method in farms is recommended for the control strategy for PRRS.
윤성환(Sung Hwan Yoon),박정(Jeong Park),권오붕(Oh Boong Kwon),윤진한(Jin Han Yun),길상인(Sang In Keel) 한국연소학회 2009 한국연소학회지 Vol.14 No.1
Experiment is conducted to grasp effects of flame curvature on flame behavior in laminar lifted-jet flames. Nozzle diameters of 0.1 and 1.0㎜ are used to vary flame curvature of edge flame. There exist three types of edge flame oscillation. These edge flame oscillations may be caused by radial heat loss at all flame conditions, by fuel Lewis numbers near or larger than unity with the help of appreciable radial conduction heat loss, and by buoyancy effects. These are confirmed by the analysis of oscillation frequencies. It is however seen that the change of lift-off height through edge-flame oscillation is mainly due to radial heat loss irrespective of Lewis number and buoyancy.
하향 전파하는 예혼합 화염의 이차 열음향 불안정성에 미치는 화염면적 변화의 영향
윤성환(Sung Hwan Yoon) 한국연소학회 2020 한국연소학회지 Vol.25 No.1
The effects of varying flame surface area due to hydrodynamic instability on secondary acoustic instability in downward propagating flames were studied experimentally. To quantitatively control hydrodynamic instability, one of intrinsic combustion instabilities, CO₂ laser irradiation technique was adopted. Because of the increase in flame surface area of the flame surface area artificially, the transition from primary acoustic instability to secondary acoustics instability occurred, and the occurrence time of secondary acoustic field became relatively shorter when the rate of variation in flame surface area was increased. However, the rate of variation in flame surface area and the wave number of corrugated structure were found to have little effect on the growth mechanism of secondary acoustic instability.
윤성환(Sung Hwan Yoon),박정(Jeong Park),권오붕(Oh Boong Kwon),김정수(Jeong Soo Kim) 한국연소학회 2009 KOSCOSYMPOSIUM논문집 Vol.- No.39
Characteristics of lift-off propane flames diluted with nitrogen have been investigated experimentally to elucidate flame oscillations. Flame stability maps are compared for the fuel tube diameters of 0.3 and 1.0㎜ to clarify the flame oscillations. Flame oscillation modes are classified into three: a pure self-oscillation, a combined form of self-oscillation and buoyancy-induced oscillation, and a combined form of self-oscillation and diffusive-thermal instability. It is shown that the self-oscillation is not relevant to a diffusive-thermal instability and a hydrodynamic instability caused by buoyancy, and appears at all lifted flame conditions irrespective of fuel Lewis number. These experimental evidences are displayed through the analysis of power spectrum for temporal variation of lift-off height. The possible scenario of the self-excitation mechanism is also addressed.