• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
• /
• pp.107-108
• /
• 2013

An experimental study in the dual swirl burner was conducted to analyze the temperature characteristics in the combustion field. The dual swirl burner consists of a main swirling pre-mixed flame with tangential swirler surrounding a pilot which can stabilize a diffusion flame or a partially premixed flame with vane swirler depending on whether fuel is supplied at the exit plane or further upstream. The purpose of this study is to analyse experimentally the characterization of flame temperature in the reacting zone, specially, according to the various combustor diameters like 80mm, 100mm, 130mm and 150mm(O.D). As a result, the temperatures of combustion field were decreased as the diameter of combustor increased. Therefore, these results can be expected that the larger diameter of combustor tend to emit less NOx emission than the small combustor.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
• /
• pp.111-112
• /
• 2013

An experimental study of a dual swirl burner was conducted to analyze NOx emission in the lean conditions. The dual swirl burner is composed of a combination of swirling jet premixed(main section) and diffusion flames(pilot section). It was operated with a co-swirling configuration and overall equivalence ratios between 0.6 and 0.8. The purpose of this study is to analyze experimentally the characterization of flame temperature and NOx concentration in reacting zone and to supply the useful experimental data for numerical simulations. The measurements of temperature and NOx concentration were captured using a thin digitally-compensated thermocouple and a sampling quartz probe with quenching effect of sudden expansion, and were measured by the NOx analyzer of chemiluminescence method. We could analyse the NOx emission characteristics comparing the temperature distributions in the lean equivalence ratios.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
• /
• pp.201-202
• /
• 2012

The isothermal flow structure and mixing characteristics of a hybrid/dual swirl jet combustor for micro-gas turbine were numerically investigated. Location of pilot nozzle, angle and direction of swirl vane were varied as main parameters with constant fuel flow rates for each nozzle. As a result, the variation in location of pilot nozzle resulted in significant change in turbulent flow field near burner exit, in particular, center toroidal recirculation zone (CTRZ) as well as turbulent intensity, and thus flame stability and emission characteristics might be significantly changed. The swirl angle of $45^{\circ}$ provided similar recirculating flow patterns in a wide range of equivalence ratio (0.5~1.0). Compared to the co-swirl flow, the counter-swirl flow leaded to the reduction in CTRZ and fuel-air mixing near the burner exit and a weak interaction between the pilot partially premixed flame and the lean premixed flame. With the comparison of experimental results, it was confirmed that the case of co-swirl flow and swirl $angle=45^{\circ}$ would provided an optimized combustor performance in terms of flame stability and pollutant emissions.

• 한국추진공학회지
• /
• 제17권5호
• /
• pp.70-79
• /
• 2013

마이크로 가스터빈용 하이브리드/이중 선회제트 연소기의 비반응 유동 및 혼합특성에 관한 수치해석 연구가 수행되었다. 고정된 열부하에서 pilot 버너의 위치, 선회 각 및 방향이 주요 변수로 검토되었다. 결과로서, pilot 버너의 위치, 선회 각 및 방향의 변화는 버너 출구 근처의 난류 유동장, 특히 중앙 재순환영역 및 난류강도의 큰 변화를 초래하며, 화염안정성 및 배기성능의 큰 변화를 동반하게 된다. 실험결과와의 비교를 통해, 하이브리드/이중 선회제트 연소기의 개발을 위하여 화염안정성 및 배기의 측면에서 pilot 버너의 최적 위치, 선회각$45^{\circ}$ 그리고 정방향 선회유동 조건들이 선택되었다.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
• /
• pp.1-4
• /
• 2014

The present work focuses on the analysis of the pulverized coal combustion aerodynamics of the dual swirl burner by the control of the swirl-modes such as the outer swirl intensity (OSI). The detailed structure of pulverized coal swirling flames with swirl-mode was studied experimentally by particle image velocimetry and local flame colors based on $OH^*$, $CH^*$, and ${C_2}^*$ radicals. For all co-swirling conditions, the internal recirculation zone (IRZ) was observed near the inner shear layer with respect to the processing vortex core structure. Furthermore, a co-rotating vortex in the outer shear layer and the exhaust tube vortex (ETV) along the central axis were observed. The intensity of $CH^*$ signal was higher with small coal particle size, conversely, the size of the distribution of the $CH^*$ signal becomes larger. Therefore, the control of the aerodynamics with changing swirl intensities may play an important role in improving both environmental and combustion performances.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
• /
• pp.242-247
• /
• 2004

An Experimental study was conducted on spray combustion using dual swirlers at different outlet angle; co-swirl and counter-swirl. To understand the characteristics of turbulent spray combustion of dual swirl flow (DSF), the axial helical annular vaned swirlers with various swirl ratios and combination of angle and direction were designed. and temperature measurements of a rapidly thermocouple insertion and measurements of soot volume fraction and microrstructure using thermophoretic sampling particle diagnostic (TSPD) as TEM were carried out. The NOx, $CO_2$, $O_2$, etc. was analyzed using emission gas analyzer. The results show that flame stability were maintained under very lean condition. for both co-swirl and counter-swirl case. And though Counter-swirl case kept the higher temperature region compared to co-swirl case, Counter-swirl combustion represented less NOx emission and soot formation than co-swirl case.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
• /
• pp.199-200
• /
• 2012

An experimental study on geometric optimization was conducted to develop a hybrid/dual swirl jet combustor for a micro-gas turbine. A hybrid concept indicating a combination of swirling jet partially premixed and premixed flames were adopted to achieve high flame stability as well as clean combustion. Location of pilot nozzle, angle and direction of swirl vane were varied as main parameters with a constant fuel flow rate for each nozzle. The results showed that the variation in location of pilot nozzle resulted in significant change in swirl intensity due to the change in flow area near burner exit, and thus, optimized nozzle location was determined on the basis of CO and NOx emissions under conditions of co-swirl flow and swirl $angle=30^{\circ}$. The increase in swirl angle (from $30^{\circ}$ to $45^{\circ}$) enhanced the emission performances, in particular, with a significant reduction of CO emission near lean-flammability limit. It was observed that the CO emission near lean-flammability limit was further reduced through the counter-swirl flow. However, there was not significant change in the NOx emission in the operating conditions (i.e. equivalence ratio of 0.6~0.7) between the co- and the counter-swirl flow.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
• /
• pp.149-152
• /
• 2012

The laboratory experiments have been conducted to investigate the effects of air preheated temperature on the emission characteristics by a model gas turbine burner with a hybrid/dual swirl jet flames configuration. The concentration of NOx and CO emissions, and flue gas temperature at combustor exit were measured with varying the equivalence ratio for different air preheated temperatures of 300, 400, 500K at atmospheric pressure. It was overall shown that the NOx and CO emissions, and flue gas temperature were decreased according to the decreasing of equivalence ratio due to the effects of lean premixed combustion regardless of the air preheated temperature. Experimental results of a lean premixed flames configuration indicated that the NOx emission was increased with higher inlet air temperature and air flow rate, which is attributed to the increasing of flue gas temperature and heat release related to the thermal NOx mechanism. But the CO emission was shown the opposite tendency, that is, the CO emission was decreased with increasing of inlet air temperature and flow rate.

• 한국추진공학회지
• /
• 제17권5호
• /
• pp.60-69
• /
• 2013

마이크로 가스터빈용 하이브리드/이중 선회 제트 연소기의 형상 최적화에 대한 실험연구가 수행되었다. 고정된 열부하에서 pilot 버너의 위치 및 선회기 베인의 방향이 주요 변수로 검토되었다. 주요 결과로서, pilot 버너 및 연료 노즐의 위치변화는 버너 출구 근처의 최소 유동면적 및 재순환 유동패턴의 변화를 발생시키며, 이로 인하여 선회강도 및 화염형상이 큰 영향을 받게 된다. 선회기 베인 각도의 증가($30^{\circ}$에서 $45^{\circ}$)는 희박가연한계 근처에서 CO 배출량을 크게 저감시킨다. 추가로 정방향 선회형상이 역방향 선회형상에 비해 보다 낮은 CO 및 NOx 배출량을 갖게 됨을 확인하였다.

• 한국추진공학회지
• /
• 제18권4호
• /
• pp.33-42
• /
• 2014

이중선회 연소기에서 다양한 화염거동과 파일럿 화염과 주 화염의 상호작용에 관한 연구가 수행되었다. 주 선회각이 $45^{\circ}$로 고정된 상태에서 파일럿 선회각도, 총 열 발생률 그리고 주 화염의 당량비가 주요 변수로 검토되었다. 주요한 결과로써, 이중선회 연소기의 상세한 화염안정화 영역이 총 발열량과 주화염의 당량비 변화를 통해 발생되는 5가지 화염모드를 통해 확인되었다. 파일럿 화염의 선회각도는 파일럿 화염의 위치 및 연소기 전체의 유동구조에 가장 큰 영향을 미치게 되며, 그 결과 내부 및 외부 화염간의 상호작용의 큰 변화를 가져온다.