• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제26회 춘계학술대회논문집
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• pp.118-122
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• 2006

액체 로켓 엔진용 가스발생기 개발을 위해서는 추진제 혼합비에 따른 연소 가스의 열역학적 물성치 예측이 필수적이다. 본 연구에서는 Lox/Jet A-1 조합의 연료 과농 가스발생기의 실 추진제 연소 시험을 통해 전체 혼합비에 따른 연소 가스의 생성 온도를 계측하였다. 연소실 내 동압 섭동 측정 및 정압 측정 결과를 이용하여 비열비, 가스 상수, 정압 비열과 같은 물성치를 간접적으로 산출해내었다. 본 실험값은 보간 계수를 이용한 예측 결과와 비교해보았을 때 동일한 대표 값을 가지는 것으로 나타나, 보간 계수 예측 방법이 설계 도구로 충분히 적용 가능하다는 것을 확인하였다.

• 한국화재소방학회논문지
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• 제21권3호
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• pp.41-46
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• 2007

본 연구에서는 지표화의 연소물질인 소나무와 굴참나무 낙엽에 대해 일정한 외부 복사열에 의한 연소특성을 분석하였다. 일정한 외부 복사열에 노출된 낙엽의 착화시간, 착화온도, 임계열유속, 질량감소속도를 측정하기 위해 낙엽의 종류별로 5개의 시료를 사용하였으며, 낙엽에 복사열을 노출시키기 위해 Mass loss calorimeter를 사용하였다. 시료 용기의 크기는 $100\;mm{\times}100\;mm{\times}12\;mm$로 소나무와 굴참나무 낙엽을 건조 후 분쇄하여 사용하였다. 연구결과, 소나무 낙엽과 굴참나무 낙엽의 시료에서 외부 복사열이 $9\;kW/m^2$ 미만에서는 착화가 발생하지 않았다. 또한, 연소시간 동안 표면온도 변화는 굴참나무 낙엽에 비해 소나무 낙엽이 더 오랜 시간동안 고온을 유지함을 알 수 있었으며, 최대질량감소속도와 평균질랑감소속도에 있어서는 굴참나무 낙엽이 소나무 낙엽 보다 더 빠르게 진행됨을 알 수 있었다. 향후, 연소특성에 대한 구체적인 연소반응 특성에 대한 실험연구가 필요할 것으로 판단된다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.13-18
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• 2006

Radiant burners are applicable to drying, preheating and curing in materials manufacturing processes. High radiation efficiency is one of the most important performance criteria for these burners. The wide variation in reported radiation efficiencies are partly due to the differences in the measurement techniques. In the present work, water cooled radiant heat flux meter was used to measure radiant heat flux from a metal fiber mat burner. Non-contact type thermometer was also utilized to measure the surface temperature of the burner. Combustion gas was measured by gas analyzers. According to the thermal loads and stoichiometric ratios, radiant heat transfer ratio and combustion performance were discussed here in.

• 수산해양교육연구
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• 제26권6호
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• pp.1435-1441
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• 2014

The fire took place in the synthetic heat transfer fluid boiler used in production process of medium density fiberboard. This study investigated pressure distribution of the first, second and third passes and the temperature in the fire burner. The boiler's internal fluid is unsteady due to the out of order inverter. As the operation continues, the flame's flow and speed are unsteady. The synthetic heat transfer fluid leak spouted about 120kg/min in the form of vapor in the early period of the fire. The flame extended to the second and third passes. The highest temperature of the second and third pass is $1059^{\circ}C$ and $1007^{\circ}C$, respectively. The synthetic heat transfer fluid spouted through the cracked part of the fire box in the first pass and accumulated on the turn table. Therefore, it is expected that the temperature of the interior of the fire box is above $1200^{\circ}C$. The temperature of the burner rises to a maximum level several times in a short period. On account of that, several explosions occur in the fire burner. Pressure distribution at steady state in combustion furnace is 2~5mAq and pressure distribution at inverter under fault condition in combustion furnace is 10~-53mAq. The decrement of coil thickness measurement for synthetic heat transfer fluid boiler is 0~5mm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.773-777
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• 2002

In this study, we analyzed the LPG and LNG sensitivity measurement and voltage variation using catalytic type gas sensor characteristics in catalytic combustion type gas detecter sensors. gas detector shall operate as intended when exposed for 24 hours to air having a relative humidity of 0~85 percent at a temperature of $20[{\mu}m]$ and humidity of 45 percent at a temperature of $-10{\sim}40[^{\circ}C]$ the gas detecter sensors are to be subjected to operation for 210 days in an area that has been detemined to be equivalent to a typical residential atmosphere with an air velocity of 50 [cm/sec]. The source of energy for a gas detector sensors employing a supplementary basic circuit is energized from a separate source of supply direct applied voltage 2.1[V], 2.2[V], 2.3[V]. As a result, it was confirmed that the relative humidity and temperature by regression each analysis, compared to the LPG characteristic graph and methane characteristics graph by a relative humidity of 0 ~ 85 [%] at a temperature range of $-10{\sim}40[^{\circ}C]$ show a similar linear pattern on the whore.

• 한국화재소방학회논문지
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• 제15권3호
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• pp.44-48
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• 2001

본 연구에서는, 접촉연소식 가스 탐지 소자를 대상으로 감도특성 및 전기적 특성을 분석하였으며, 24시간 동안 공기중에 노출시킨 후 온도($20^{\circ}c$, $40^{\circ}c$)와 상대습도(65%, 85%)에서 작동시켜 분석하였다. 또한 동일한 주거환경에서 210일 동안 50 cm/sec 유속을 유지하며 가스탐지소자의 동작을 실험하였다. 가스 탐지센서에 공급 전원은 기본회로에 직류 전압별(2.1V, 2.2V, 2.3V)로 인가하였다. 따라서, 상대습도와 온도에 의한 이소부탄과 메탄 특성그래프를 각각 분석한 결과 전반적으로 선형적인 증가를 보임을 확인할 수 있다.

• 대한기계학회논문집B
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• 제28권10호
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• pp.1184-1192
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• 2004

Experimental investigations were carried out in an atmospheric pressure, optically accessible and laboratory-scale dump combustor operating on methane gas. The objective of this study was to obtain the phase-resolved gas temperatures at different phases of the oscillating pressure cycle during unstable combustion. CARS temperature measurements were made at several spatial locations under lean premixed conditions to get the information on temperature field within the combustor. Also the effect of incomplete fuel-air mixing on phase-resolved temperature fluctuation was investigated. Results including phase-resolved averaged temperature, normalized standard deviation and temperature probability distribution functions (PDFs) were provided in this paper. Temperature PDFs gave an insight on the flame behavior. And strong correlation between phase-resolved temperature profile and pressure cycle was observed. Results of the phase-resolved high temperature gave an additional information on the perturbation of equivalence ratio at flame as well as the effect of mixing quality on NOx emission characteristics.

• 설비공학논문집
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• 제7권4호
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• pp.600-610
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• 1995

When combustion gas is cooled down below the dew point of sulfuric acid vapor in the heat recovery systems, condensation occurs. Since the condensed sulfuric acid solution causes low-temperature corrosion in materials, it is important to measure the SOx dew point by electric measurement. In this study, two kinds of probes having electric gaps of 1mm or 2mm were used. and experiments were carried out by the parameters of sulfuric acid vapor and water vapor concentration. The changes of electric current caused by sulfuric acid condensed on the surface of probe according to the cooling rate and the probe head surface temperature were sudied. The opimum cooling rate was decreased with the increasing of water vaper concentration regardless of sulfuric acid concentration. The sensitivity of electric current is improved for the narrower gap(1mm) of ring electrodes, but it rarely affects the SOx dew point measuring of different probes according to the change of cooling rate.

• 대한기계학회논문집B
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• 제21권2호
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• pp.213-223
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• 1997

Premixed flame is better than diffusion flame to accomplish a high loading combustion. Since the turbulent characteristics of unburned mixture has a great influence on the flame structure, it is general that many researchers realize a high loading combustion with strengthening turbulent intensity of unburned mixture. Because turbulent premixed flame reacts efficiently on the condition of distributed reaction region, we made high turbulent premixed flame in the doubled impingement field. We investigated turbulent characteristics of unburned mixture with increasing shear force and visualized flames with direct and Schlieren photographs. And the combustion characteristics of flame was elucidated by instantaneous temperature measurement with a thermocouple, by ion currents with a micro electrostatic probe, by radical luminescence intensity and local equivalence ratio. Extremely strong turbulent of small scale is generated by impingement of mixture, and turbulent intensity of unburned mixture increased with the mean velocity. As a result of direct photographs, visible region of flame became longer due to increasing central direction flux. But as strengthed turbulent intensity, visible region of flame turned to shorter and reaction occurred efficiently. As strengthened turbulent intensity of mixture with increasing flux of central direction, maximum fluctuating temperature region moved to radial direction and fluctuation of temperature became lower. The reason is influx of central direction which caused flame zone to move toward radial direction, to maintain flame zone stable and to make flame scale smaller.

• 한국추진공학회지
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• 제18권1호
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• pp.73-84
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• 2014

본 논문에서는 화학발광 계측을 통한 연소화염의 당량비, 열방출율과 같은 물리량 판단에 대한 최신 연구결과를 정리 분석하였다. 현대의 연소장치는 연소의 동적 안정성 증대 및 공해물질 배출억제를 위해 세밀한 제어가 필요하다. 화학발광 세기 계측을 통한 물리량 파악은 그 적용에 있어서 많은 상대적 장점을 지니고 있다. 그러나 본 방법은 당량비, 연소압력, 입구온도, 난류세기, 연료 종류 등에 의해 많은 영향을 받는다. 연구결과를 종합하면, 메탄/공기 예혼합 화염에서 $CH^*/OH^*$가 연료 과농 조건을 제외하고 당량비와 밀접한 관계가 있다. 또한 넓은 공간에서 측정된 $OH^*$, $CH^*$ 신호는 전체 열방출율과 비례관계를 갖는 것으로 판단된다.