• 대한기계학회논문집B
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• 제41권6호
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• pp.397-407
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• 2017

본 논문에서는 연비손실 없이 높은 $NO_X$ 저감성능을 보이는 승용 디젤 엔진의 SCR 시스템을 위한 요소수의 분사전략을 제시하였다. 배출되는 $NO_X$량 대비 요소수가 화학량론적 1:1인 피드포워드 분사 전략과 함께 모델기반의 촉매 내 $NH_3$ 흡장률 추정 기법을 통하여 피드백 분사 제어전략을 함께 사용함으로써 과도상태에서 $NO_X$ 저감성능과 $NH_3$ 슬립 성능을 모두 만족시키고자 하였다. 제안된 분사전략을 적용하여 디젤산화촉매기와, 미립자필터가 장착된 2.2L 디젤 엔진을 갖춘 실제 차량에서의 실험을 통하여 제어기의 높은 $NO_X$ 저감률과 낮은 $NH_3$ 슬립 성능을 검증하였다.

• 한국대기환경학회지
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• 제23권6호
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• pp.699-707
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• 2007

This study was carried out to investigate the reaction characteristics of corona/catalyst hybrid $DeNO_x$ process. The experiments were performed by using the multi-staged pin-to-hole type corona reactor which is enable to control the pin-to-hole gap and to insert the catalyst. Also, used for this study, were catalysts which commercially used Pt, Pd and $TiO_2$, and oxygen and hydrocarbon ($C_2H_4$) as reagents. In the syn-gas test, at high temperatures in the range of $100{\sim}200^{\circ}C$, the corona-only $DeNO_x$ process did not reduce the $NO_x$ concentration effectively. However in the presence of ethylene and oxygen as reagents, the $NO_x$ removal efficiency was better at these high temperatures than corona-only $DeNO_x$ process. In addition, coronal catalyst hybrid process with $TiO_2$ showed more efficiency of $NO_x$ removal than Pt and Pd catalyst, because the $TiO_2$ catalyst was more active than Pt and Pd catalyst to converse the $NO_2$ to $HNO_3$. Furthermore, at the condition of real diesel exhaust gas, the $DeNO_x$ efficiency of corona/catalyst hybrid process was not good at higher reaction temperature and plasma density.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.115-120
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• 2001

The present study examined the possibility of $NO_{x}$ reduction in the high temperature industrial furnaces. duct burner of gas turbine cogeneration and two-stage gas turbine combustor. The experimental study was carried out for the diffusion flame of second stage combustor with the variations of oxygen concentration and supplying rate of hot exhaust gas from first stage combustor. It also examined the flammability range and $NO_{x}$ formation of the second stage combustor in which the fuel is supplying into the mixture of oxygen hot exhaust gas from first stage combustor. The results show that the enrichment of oxygen and increase of exhaust gas lead to increase the $NO_{x}$ up to 50 ppm with 23% $O_{2}$ condition.

• 한국수소및신에너지학회논문집
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• 제11권1호
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• pp.1-9
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• 2000

The goals of this research are to understand the $NO_x$ emission in direct injected diesel engine with premixed hydrogen fuel. Hydrogen fuel was supplied into the test engine through the intake pipe. Amount of hydrogen-supplemented fuel was 70 percent basis heating value of the total fuel. The effects of exhaust gas recirculation(EGR) on $NO_x$ emission were studied. The exhaust gas was recirculated to the intake manifold and the amount of exhaust gas was controlled by the valve. The major conclusions of this work include: (i) the tested engine was run without backfire under 70 percent hydrogen fuel supplemented; (ii) the peak cylinder pressure was decreased with increase of EGR ratio due to the decrease of oxygen concentration in an intake pipe; and (iii) $NO_x$ emission was decreased by 77% with 30% EGR ratio. Therefore, it may be concluded that EGR is effective method to lower $NO_x$ emission in hydrogen fueled diesel engine.

• 청정기술
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• 제21권3호
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• pp.184-190
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• 2015

대부분의 LNT 촉매는 낮은 온도 영역에서의 NO_x 산화를 위하여 Pt와 같은 귀금속류를 사용하는 것은 경제적인 부담을 가지고 있다. 따라서, 본 연구는 이러한 문제를 해결하기 위하여 시도되었다. 즉, Pt, Pd, Rh 등과 같은 귀금속류(platinum group metal, PGM)를 사용하지 않는 LNT (lean NO_x trap)용 DeNO_x 촉매를 개발하기 위해 시도하였다. 이를 위해서 예비실험을 통해 Pt등 귀금속류등의 PGM (platinum group metal)을 사용하지 않는 Al/Co/Ni 혼합 금속 산화물을 선정하였다. 궁극적으로는, 선정된 촉매의 소성온도에 따른 물리화학적 특성 변화가 NO_x 전환율에 미치는 영향을 살펴보고자 하였다. 이들의 물리화학적인 성질을 평가하기 위해 XRD, EDS, SEM, BET 분석을 실시하였다. 이러한 평가를 실시한 결과, 모든 소성온도에서 혼합금속 산화물은 Co₂AlO₄ 및 NiAl₂O₄의 스피넬 구조가 혼재되어 있는 것으로 나타났고, NO_x 기체들의 산화-환원 반응이 이루어지기에는 충분한 기공부피와 기공크기를 갖고 있음을 알 수 있었다. 그러나 NH₃-TPD 분석 결과에서는 소성온도가 700 ℃ 이하를 유지해야 하는 것으로 판단되었다. 더욱이 ramp test를 통해서는 NO 및 NO_x 전환율을 동시에 만족할 수 있는 시료는 소성온도는 500 ℃에서 처리된 경우임을 알 수 있었다. 이러한 결과 등을 바탕으로, Al/Co/Ni=1.0/2.5/0.3 혼합 금속 산화물의 최적 소성온도는 500 ℃임을 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.203-206
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• 2000

In this experiment, an attempt to use pellets($BaTiO_3$, $TiO_2$, ${\gamma}-Al_2O_3$, sludge) for $NO_x$ removal was conducted The effect of pellets on NO removal from simulated flue gas was experimentally investigated for packed-bed reactor of plate-plate geometry. An experimental investigation has been conducted for NO concentration of 50ppm balanced by air, and gas flow rate of $5{\ell}/min$. Ceramic pellets were used for surface discharge and the sludge pellets was added on $BaTiO_3$ and $TiO_2$ to increase $NO_x$ removal rate. In the result, $NO_x$ removal rate using $TiO_2$ was better than other pellets. $NO_2$ segnificatly generated by using $BaTiO_3$ pellets and sludge pellets used with $BaTiO_3$ decreased $NO_2$ generation.

• 한국응용과학기술학회지
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• 제32권3호
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• pp.372-376
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• 2015

The experiment was performed using the cleaning precipitator To investigate the absorption efficiency of the $SO_X/NO_X$ of the aqueous ammonia solution. Concentration of the cleaning liquid is 0.1, 0.5, and 1.0% with increasing absorption efficiency has improved. However, the reaction shown only a difference in time. Absorption efficiency has improved in accordance with the gas residence time. When the direction of the same gas and the cleaning liquid is determined that there is the effect of increasing the residence time. The relative impact of $SO_X$ and $NO_X$ is this likely to react slower than $SO_X/NO_X$. The yield is determined to require adjustment of the cleaning dust collector according to the concentration of the next gas.

• 한국운동역학회지
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• 제20권4호
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• pp.487-495
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• 2010

The purpose of this study was conducted to make a comparative biomechanical analysis of X-factor and X-factor stretch during driver and iron swing. The subjects were composed of 10 professional golfers with more than 10 years career. The result was as follows: First, the analysis of the back swing with driver and iron swing showed no differences statistically between both the timing in horizontal rotating of shoulder and hip, the time required for X-factor stretch also showed no differences statistically. Second, the back swing with a driver swing showed more maximum horizontal rotation of shoulder and hip joint than the back swing with an iron swing, but the twist of shoulder and hip that was X-factor stretch angle showed no difference. Third, the GRF of the max value for the left and right foot during shoulder and hip horizontal rotation of back swing showed no differences statistically in the movement of driver and iron swing during the back swing, and the GRF of X-factor stretch for the left and right foot showed no differences statistically in driver and iron swing. Therefore the result of this research showed that the operation of torso(X-factor stretch) and weight shifting were similar although the horizontal rotation of body was different during the driver and iron swing.

• 센서학회지
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• 제18권4호
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• pp.263-268
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• 2009

With the increasing number of automobiles, the problem of air pollution from the exhaust gases of automobiles has become a critical issue. The principal gases that cause air pollution are nitrogen oxide or NO$_x$(NO and NO$_2$), and CO. Because NO$_x$ gases cause acid rain and global warming and produce ozone(O$_3$) that leads to serious metropolitan smog from photochemical reaction, they must be detected and reduced. Mixtures of WO$_3$ and $In_2O_3$(WO$_3$:$In_2O_3$=10:0, 7:3, 5:5, 3:7, and 0:10 in wt.%), which are NO$_x$ gas-sensing materials, were prepared, and thick-film gas sensors that included a heater and a temperature sensor were fabricated. Their sensitivity to NO$_x$ was measured at 250$\sim$400$^{\circ}C$ for NO$_x$ concentrations of 1$\sim$5 ppm. The $In_2O_3$ thick-film sensor showed excellent sensitivity($R_{gas}/R_{air}$=10.22) at 300$^{\circ}C$ to 5-ppm NO. The response time for 70 % saturated sensitivity was about 3 seconds, and the sensors exhibited very fast reactivity to NO$_x$.

• 청정기술
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• 제22권3호
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• pp.141-153
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• 2016

화력발전소, 소결공정, 소각장 등과 같은 수많은 배출원들은 배연탈질시스템을 적용하는데 V₂O₅/TiO₂계 모노리스 촉매상에서 NH₃를 환원제로 사용하는 선택적촉매환원 기술이 대표적이다. 현장에서 설치·운영되는 모든 탈질시스템은 예외없이 운전시간에 따른 촉매비활성화를 수반하므로 이에 효과적이고 경제적으로 대처할 수 있는 탈질성능 유지와 촉매관리를 위한 체제와 전략이 요구된다. 본 논고에서는 이들에 관한 구체적인 전략수립과 이에 기반한 탈질시스템 운영방법을 살펴보고, 신촉매 또는 재생촉매의 추가나 대체를 통한 탈질성능 관리와 경제성을 고려한 탈질촉매 재생기술을 다루고자 한다.