• 한국추진공학회:학술대회논문집
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• 한국추진공학회 1998년도 제10회 학술강연회논문집
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• pp.31-31
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• 1998

위성체의 보조추진시스템은 임구궤도까지의 궤도진입 및 임무궤도상에서의 속도 또는 자세제어에 필요한 임펄스를 제공한다. 단일하이드라진 추력기는 하이드라진(H$_2$H$_4$)과 자발적 촉매(Shell 405)의 발열 및 흡열 열분해 반응에 의해 발생하는 질소($N_2$), 수소(H$_2$), 암모니아(NH$_3$), 혼합가스를 노즐을 통해 방출하므로써 요구되는 impulse를 얻는다. 단일하이드라진 추력기 설계는 주입기, 촉매대, 노즐과 기타 설계 형태에 따른 다지관, 링, 스크린, 지지판 등의 부수적인 부품으로 구성된다. 추력기 제작 과정은 크게 piece-parts 기계가공, HEA(Head End Assembly)와 TCA(Thrust Chamber Assembly)로 구성되고 각 세부공정마다 전수시험 및 검사를 가진다. 연소시험설비는 최소 모사진 공 수준이 고도 100,000 ft(8.4 torr)를 만족시킬 수 있는 진공설비, 시험제어부, 성능변수 측정 및 처리부, 추진제 가압 공급부, 기타 환경 안전 및 부대 설비로 구성된다. 추력기 연소성능시험 절차는 추진제 충전 및 오염 여부 표본 검사, 가압 및 공급 라인 이상여부 확인, 추력기 장착, 추진제 가압 및 공급, 시험장치 보정, 진공 모사 및 연소성능시험, data 처리 등으로 구성된다.

• 대한기계학회논문집B
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• 제32권11호
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• pp.870-877
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• 2008

Numerical analysis is applied to model Pt-catalyzed reaction in a micro-scale combustor fueled by butane. The reaction constants of catalytic oxidation are determined from plug flow model with the experimental data. Orders of magnitude between the chemical reaction rate and the mass transfer rate are carefully compared to reveal which mechanism plays a dominant role in the total fuel conversion rate. For various conditions of fuel flow rate and surface temperature, the profiles of Sherwood number are investigated to study the characteristics of the mass transport phenomena in the micro-tube combustor.

• 대한기계학회논문집A
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• 제33권3호
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• pp.237-242
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• 2009

MEMS catalytic combustors were fabricated to use in micro-power sources as a heat source. The combustor was fabricated by photolithography and anisotropic wet etching of photosensitive glass wafers. Two different catalyst loading methods were used to complete the fabrication of the combustors. For thin film type, the $Al_2O_3$ was washcoated on the surface of the combustion chamber as a catalyst support, and for packed-bed type, ceramic foam was inserted after Pt was coated. The volume of the combustors was 1.8 $cm^3$ and 16W of heat was generated using the fabricated combustors with hydrogen. The energy density of combustor was about 8.9 W/$cm^3$.

• 유기물자원화
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• 제18권1호
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• pp.66-72
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• 2010

본 연구는 경기도 A지역 자원회수시설에서 연소온도의 변화에 따른 NOx, SOx, CO, HCL, DUST의 발생변화와 보일러 배출가스 온도, 보일러 출구산소 농도, 반건식 반응탑 출구온도, 촉매탑온도, 배출가스 온도의 변화를 분석하였다. SOx, CO, Hcl, DUST는 자원회수시설 내의 연소온도가 상승함에 따라 거의 5 ppm 미만의 일정한 값을 유지한 반면 NOx 는 40 ppm에서 70 ppm으로 증가하는 추세였다. 한편 보일러 배출가스 온도와 촉매탑 온도는 일정치를 유지하였으나 보일러 출구의 산소농도는 조금씩 감소하는 결과를 나타내었다.

• 한국추진공학회지
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• 제18권6호
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• pp.19-26
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• 2014

70 N급 하이드라진 추력기 개발모델의 압력 불안정 특성 고찰을 위한 지상연소시험을 수행하였다. 단일추진제급 하이드라진이 연소시험용 추진제로 선정되었고, 촉매대에는 $Ir/Al_2O_3$ 촉매를 충전하였다. 추력실 직경변화가 연소안정성에 미치는 영향을 규명하기 위해 길이직경비(L/D) 1.03, 1.13, 1.26을 갖는 하단 추력실을 시험변수로 적용한 성능평가가 수행되었다. 개발모델은 50 Hz 근처의 저주파 불안정 특성을 내재하고 있으며, L/D 증가 및 작동압력의 감소가 정체실의 압력진동을 증대시킨다는 사실이 확인되었다.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2002년도 추계학술대회 논문집
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• pp.263-264
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• 2002

연소시설에서 배연가스중의 NOx 배출을 저감하기 위하여 선택적 촉매 환원법(SCR)과 선택적 무촉매 환원법(SNCR)이 널리 이용되고 있다. 이러한 촉매처리는 Pt와 같은 귀금속이 포함된 촉매 하에서 암모니아를 환원제로 사용하였으나, R와 같은 귀금속의 경우 배연가스내에 함유된 중금속이나 비소(Arsenic), SOx, 비산재(fly ash)등에 의해 쉽게 비활성화(deactivation)되는 단점이 있다(Sumitra R et al., 1995). (중략)

• 대한기계학회논문집B
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• 제33권3호
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• pp.149-155
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• 2009

In this work 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

• 동력기계공학회지
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• 제7권3호
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• pp.12-17
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• 2003

The purpose of this study is to observe the purification characteristics of NOx, CO and HC in various catalysts and excess air ratio conditions. For this purpose, we installed various catalysts on the back stream of the coaxial diffusion burner with swirler. As the result, in the case of NOx, Pt-Rh catalyst shows very high value that is more than 90%-conversion efficiency without the relation with the excess air ratio. After excess air ratio of ${\alpha}=1.14$, it shows that the conversion efficiencies were more than 80% in the every Pt catalyst in the view of conversion of every exhaust with changing of the excess air ratio.

• 한국연소학회지
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• 제10권3호
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• pp.17-24
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• 2005

A sub-millimeter scale catalytic combustor with a simple plate-shaped combustion chamber was fabricated. A porous ceramics support coated with platinum catalyst was placed in the chamber. The combustor has a gallium arsenide window on the top that is transparent to infrared ray. The temperature distribution in the combustion chamber was measured using infrared thermal imager while hydrogen-air premixture is steadily supplied to the combustor. The area where the catalytic reaction took place broaden for higher flow rate and lower equivalence ratio made activated area in the combustion chamber broaden. The amount of coated platinum catalyst did not affect the reaction. Stop of reaction, which is similar to flame quenching of conventional combustion, was investigated. Large content of heat generation and broad activated area are essential criteria to prevent stop of reaction that has a bad effect on the combustor performance.

• 한국수소및신에너지학회논문집
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• 제22권6호
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• pp.878-883
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• 2011

Effect of flow uniformity on the reaction characteristics of a catalytic combustor for high temperature fuel cell system has been experimentally investigated in the present study. One of the most important factor in designing catalytic combustion is to avoid hot spot in catalysts. In this regard, it is very important to secure flow uniformity of combustor inlet. A couple of perforated plates were applied at the front of catalyst region as flow uniformity device with minimal pressure drop. Results show that the velocity and temperature profile became more uniform when applying the flow uniformity device. CO and $CH_4$ emissions at the combustor exit were decreased and the average exit temperature was slightly increased with the flow uniformity device.