• 한국가스학회:학술대회논문집
• /
• 한국가스학회 1997년도 추계학술발표회 논문집
• /
• pp.7-13
• /
• 1997

• 한국연소학회지
• /
• 제16권1호
• /
• pp.46-51
• /
• 2011

Exhaust gas of an industrial furnace used at such as metallurgy or ceramic manufacturing usually contains thermal energy with high temperature which can be recycled by heat exchanger. However, when the temperature of the exhaust gas is high such as more than $1,000^{\circ}C$, ordinary metallic heat exchanger cannot fully recover the heat due to the limitation of operating temperature depending on the material property. In the present study, a compact ceramic heat exchanger of cross flow type is introduced and evaluated by heat exchange rate and operating temperature. The ceramic heat exchanger can endure the gas temperature more than $1,300^{\circ}C$, and its volumetric heat exchanging rate exceeds 1 MW/$m^3$. The experimental data is also compared with the previous numerical result which shows reasonable agreement. Meanwhile, the gas leakage rate is measured to be about 3~4%, and heat loss to environmental air is about 23~26% of the fuel energy.

• 한국전산구조공학회논문집
• /
• 제35권5호
• /
• pp.299-308
• /
• 2022

본 논문은 슬로싱 상태에 놓인 포화 상태 액체수소탱크에서 열 유속 및 BOG(Boil-off gas)의 경향을 다루고 있다. 특히, 액체-기체간의 침투 및 혼합에 의한 열 교환에 관심을 두었다. 먼저, VOF(Volume of fluid)와 Eulerian 기반의 다상 유동모델로 모형 슬로싱 실험을 모사하여 압력을 예측하고 계측된 값과 비교하였다. 자유 수면 및 충격 압력 실험 결과와 해석 결과를 비교하였으며, 유체의 속도 예측에서 정확할 수 있음을 간접적으로 증명하였다. 그리고 2차원의 Type-C 원통형 수소탱크를 대상으로 다상열유동해석을 수행하였다. 이때 포화상태에 놓인 액체 및 기체수소를 가정하고, 해석을 통해 각 상간의 혼합에 의한 열 교환의 수준을 확인하고자 하였다. 단, 상간의 열 교환만을 관심으로 두고 있었으므로 질량전달 및 기화모델은 해석에서 제외하였다. 최종적으로 상의 혼합으로 인해 액체수소로 유입되는 열 유속의 기여도에 대하여 정리하였다. 또한 액체수소로 유입되는 열 유속과 집중 질량 기반의 간이식을 통해 BOG 발생량 및 경향을 예측하고 분석하였다.

• 접착 및 계면
• /
• 제10권3호
• /
• pp.141-147
• /
• 2009

본 연구는 web spray 분사방식으로 핫멜트 접착제를 이용하여 high performance hybrid chemical filter (HPHCF)를 제조하였다. HPHCF은 이온교환 수지와 PP 부직포를 사용하였고, HPHCF의 제조 시 최적 조건은 핫멜트의 온도는 $170^{\circ}C$에서 분사압력은 50 psi일 때 최적의 제조 조건을 나타내었다. 제조된 HPHCF의 특성 및 암모니아 흡착성능을 측정하였다. HPHCF 이온교환용량은 수지 부착량이 증가함에 따라 증가하였으며 단일 수지와 이온교환섬유의 이온교환용량보다 크게 나타났다. 또한 암모니아의 제거율은 HPHCF의 충진 밀도가 증가할수록 증가하였으며 흡착 파과시간은 13 min으로 단일 섬유나 수지에 비해 길게 나타났고 최대 암모니아 흡착량은 98%이었다. 또한 암모니아 흡착 파과시간은 유량 및 농도가 증가함에 따라 빠르게 진행되었다.

• 한국정보통신학회논문지
• /
• 제11권6호
• /
• pp.1141-1149
• /
• 2007

본 논문에서는 신발금형의 가스벤트 착탈 작업을 효율적으로 진행하기 위해 이미지 프로세싱을 통한 가스벤트 착탈위치 탐색과 정밀 제어로 착탈 작업을 수행하는 교환 장치의 두 가지 기술을 다루고 있다. 이 두가지 방법을 적용하기 위한 핵심적인 이슈는 신발 금형의 가스벤트 교환 위치의 중심을 어떻게 하면 정확하게 찾아내는가이다. 이러한 자동 교환 장치의 사용은 가스벤트 착탈 시간을 줄이며 아울러 노동력의 절감 제품의 생산에 드는 비용을 최소화하는 등의 여러 가지 이점을 가져다 준다. 이 장치를 사용하여 실험을 통해 검증한 결과 가스벤트 교환 장치의 사용이 더 안정적이고 효율적이며 착탈 시간을 줄여 공정시간을 단축하는 것을 증명할 수 있었다.

• Nuclear Engineering and Technology
• /
• 제33권1호
• /
• pp.83-92
• /
• 2001

The properties of off-gas generated from vitrification process of ion-exchange resin were characterized. Theoretical composition and flow rate of the off-gas were calculated based on chemical composition of resin and it＇s burning condition inside CCM. The calculated off-gas flow rate was 67.9Nm$^3$/h at the burning rate of 40kg/h. And the composition of off-gas was avaluated as $CO_2$(41.4%), steam(40.0%), $O_2$(13.3%), NO(3.6%), and SO$_2$(1.6%) in order. Then, actual flow rate and composition of off-gas were measured during pilot-scale demonstration tests and the results were compared with theoretical values. The actual flow rate of off-gas was about 1.6 times higher than theoretical one. The difference between theoretical and actual flow rates was caused by the in-leakage of air to the system, and the in-leakage rate was evaluated as 36.3Nm$^3$/h. Because of continuous change in the combustion parameters inside CCM, during demonstration tests, the concentration of toxic gases showed wide fluctuation. However, the concentration of CO, a barometer of incompleteness of combustion inside CCM, was stabilized soon. The result showed quasi-equilibrium state was achieved two hours after feeding of resin.

• 한국유체기계학회 논문집
• /
• 제19권6호
• /
• pp.19-25
• /
• 2016

Anti-icing is important in gas turbines because ice formation on compressor inlet components, especially inlet guide vane, can cause performance degradation and mechanical damages. In general, the compressor bleeding anti-icing system that supplies hot air extracted from the compressor discharge to the engine intake has been used. However, this scheme causes considerable performance drop of gas turbines. A new method is proposed in this study for the anti-icing in combined cycle power plants(CCPP). It is a heat exchange heating method, which utilizes heat sources from the heat recovery steam generator(HRSG). We selected several options for the heat sources such as steam, hot water and exhaust gas. Performance reductions of the CCPP by the various options as well as the usual compressor bleeding method were comparatively analyzed. The results show that the heat exchange heating system would cause a lower performance decrease than the compressor bleeding anti-icing system. Especially, the option of using low pressure hot water is expected to provide the lowest performance reduction.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2008년도 하계학술발표대회 논문집
• /
• pp.529-534
• /
• 2008

Interzonal air movements are important to characterize overall ventilation performance of complicated multi-zone buildings. Tracer gas techniques are widely used to measure ventilation rates, ventilation effectiveness, and interzonal air movements. Depending on the number of gases used, they are divided into single and multi tracer gas methods. This paper deals with the comparison of the tracer gas methods in measuring air exchange rate between rooms. Experiments have been conducted in a simple two-room model with known airflow rates. In multi-gas procedure, the concentration decays of two tracer gases, i.e SF6 and R134a are measured after simultaneous injections in each room. The single tracer gas method is also applied by injecting SF6 gas with a time lag between two rooms. The data reduction procedures are developed to obtain the interzonal airflow rate using the matrix inversion, and various data manipulation methods are tested, such as data shift, interpolation, and smoothing. Uncertainty for each airflow rate is investigated depending on the parameters based on the setting values.

• 설비공학논문집
• /
• 제21권11호
• /
• pp.606-612
• /
• 2009

Interzonal air movements are important to characterize overall ventilation performance of complicated multi-zone buildings. Tracer gas techniques are widely used to measure ventilation rates, ventilation effectiveness, and interzonal air movements. Depending on the number of gases used, they are divided into single and multi tracer gas methods. This paper deals with the comparison of the tracer gas methods in measuring air exchange rate between rooms. Experiments have been conducted in a simple two-room model with known airflow rates. In multi-gas procedure, the concentration decays of two tracer gases, i.e SF6 and R134a are measured after simultaneous injections in each room. The single tracer gas method is also applied by injecting SF6 gas with a time lag between two rooms. The data reduction procedures are developed to obtain the interzonal airflow rate using the matrix inversion, and various data manipulation methods are tested, such as data shift, interpolation, and smoothing. Uncertainty for each airflow rate is investigated depending on the parameters based on the setting values.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2012년도 임시총회 및 하계학술연구발표회
• /
• pp.70-71
• /
• 2012

In summary, the BLS experiments was applied to investigate the magnetic properties of $Co_{40}Fe_{40}B_{20}$ thin films. We find that the exchange stiffness constant decrease with increasing Ar gas pressure.