• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.515-518
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• 2007

Because of their low operating and maintaining costs, ground-source heat pump(GSHP) systems are an increasingly popular choice for providing heating, cooling and water heating to public and commercial buildings. Despite these ad- vantages and the growing awareness, GSHP systems to residential sectors have not been adopted in Korea until recently. A feasibility study of a residential GSHP system was therefore conducted using the traditional life cycle cost(LCC) analysis within the current electricity price framework and potential scenarios of that framework. As a result, when the current residential electricity costs for running the GSHP system are applied, the GSHP system has weak competitiveness to conven- tional HVAC systems considered. However, when the operating costs are calculated in the modified price frameworks of electricity, the residential GSHP system has the lower LCC than the existing cooling and heating equipments. The calculation results also show that the residential GSHP system has lower annual prime energy consumption and total pollutant emissions than the alternative HVAC systems considered in this work.

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

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.19-25
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• 2006

Energy efficient and low pollution combustion systems the use gaseous fuels have been in great demand in recent year. Radiant burner in many different forms are emerging as very desirable combustion systems for same reason. Porous radiant burners are used in drying, preheating and curing, and in other type of materials processing and manufacturing processes. However, little knowledge is available about the operating characteristics and the structure of flames in porous ceramic fiber radiant burners. The objective of the present work is to investigate the global performance characteristics of the ceramic fiber burner. A detailed study which includes the spectral intensity, gas temperature, radiation efficiency and global pollutant emissions. Another objective is to study the flame structure of the ceramic fiber burner by measuring the local gas temperature. The results indicate that ceramic fiber burner do offer a 19-44% gain in radiant efficiency. The ceramic fiber burner exhibit significant spectral intensity peaks in the band at $2.0-2.5{\mu}m$. The local temperature distribution inside the mat and near the mat surface as a function of the equivalence ratio can be reasonably interpreted by the relation of the heat balance in the mat and movement of the reaction zone. Nox emission from ceramic fiber burner is less than 25ppm throughout the operating range.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.35-42
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• 2001

The diesel engine exhaust gas is know as one of the causes to produce photochemical smog, which causes damage on environmental. However, due to the high thermal efficiency and low carbon dioxide emission, the usage of a diesel engine is prevailed. In this study, the DC non-thermal plasma technology used to the particulate matter (PM) aftertreatment. The exhaust gas characteristics and energy density were investigated on the dynamometer test bed and chassis dynamometer with CVS-75 mode in a passenger diesel car. It was reported that the smoke removal efficiency has around the 70% in the dynamometer test with 80W energy consumption and the PM removal efficiency has the 68% in the real car test. The NOx also reduced the 20% according to electrode type respectively. Considering these results, plasma technology is one of the ways to simultaneously removing method the particulate matter (PM) and NOx.

• 한국연소학회지
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• 제14권4호
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• pp.25-32
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• 2009

In commercial combustion systems, heavy oil is one of main hydrocarbon fuel because of its economical efficiency. Regarding heavy oil combustion, due to increasing concerns over environmental pollutants such as carbon monoxide, unburned hydrocarbon and nitrogen oxides, development of low pollutant emission methods has become an imminent issue for practical application to numerous combustion devices. Also a great amount of effort has been tried to developed effective methods for practical using of biomass. It is also an important issue to reduce carbon tax. In this paper, an experimental study has been conducted to evaluate the effect of biomass reburning on NOx formation in a heavy oil flamed combustion furnace. Experiments were performed in flames stabilized by a multi-staged burner, which was mounted at the front of the furnace. Experimental tests were conducted using air-carried rice husk powder and LNG as the reburn fuel and heavy oil as the main fuel. The paper reports data on flue gas emissions and temperature distribution in the furnace for several kinds of experimental conditions. NOx concentration in the exhaust has decreased considerably due to effect of reburning. The maximum NOx reduction rate was 62% when the rice husk was used by reburn fuel, however it was 59% when the LNG was used by reburn fuel. The result shows the positive possibility of biomass reburning system for optimal NOx reduction.

• 한국환경보건학회지
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• 제22권3호
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• pp.28-36
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• 1996

The objects of this study were to investigate emissions of air pollutant the particles as well as the combustibility of the low grade domestic anthracite coal and imported high-calorific bituminous coal in the fluidized bed coal combustor. The production of air pollution from anthracite-bituminous coal blend combustion in a fluidized bed coal combustor was evaluated. The effects of air velocity and anthracite fraction on the reaching time of steady state condition was also evaluated. We used coal samples the domestic low grade anthracite coal with heating value of 2,010 kcal/kg and the imported high grade bituminous coal with heating value of 6,520 kcal/kg. The experimental results are presented as follows. The time of reaching to steady state was affected by the temperature variation. The steady state time was about 120 minute at 0.3 m/s which was the fastest. It has been found that $O_2$ and $CO_2$ concentration were reached steady state at about 100 minute. As the height of fluidized bed becomes higher, the concentration s of $SO_2$ and $NO_x$ mainly increased. The concentration of freeboard was the highest and emission concentration was diminished. Also, as anthracite fraction increased, the emission of $SO_x$ concentration was increased. But, it has been found that the variation of $NO_x$ concentration with anthracite fraction was negligible and the difference of emission concentration according to air flow rates was negligible, too. It has been found that $O_2$ concentration decreased and $CO_2$ concentration increased as the height of fluidized bed increased. As anthracite fraction increased, the mass of elutriation particles increased, and $CO_2$ concentration decreased. Also, as air velocity increased, $O_2$ concentration decreased and $CO_2$ concentration increased. Regardless-of anthracite fraction and flow rate, the combustible weight percentage in elutriation particles were high in the case of fine particles.

• 한국산학기술학회논문지
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• 제22권6호
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• pp.492-498
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• 2021

본 연구는 수송부문에서 오염물질 배출 비중이 큰 화물차의 통행량에 영향을 미치는 요인을 분석하기 위하여 다중회귀모형을 추정하였으며, 모형 추정 결과 지역별 인구수, 도시지역 면적, GDP, 업종별(농업, 임업 및 어업, 광업, 제조업, 도매 및 소매업) 사업체수 등이 주요 변수로 검토되었다. 이러한 변수는 화물차 특성(업종, 톤급)에 따라 상이하게 나타나므로 차량 운행제한 등 관련 정책 추진 시에는 지역별 화물차 특성에 따른 통행량을 충분히 고려해야 할 필요가 있다. 특히 물류터미널 등 화물차 통행량이 많은 물류거점이 위치하지 않은 지역에 대해서는 화물차 통행에 영향을 미치는 지역별 요인을 고려하여 차량 운행제한 대상 지역을 검토해야 할 필요가 있다. 특히 본 연구의 결과에서 제시된 바와 같이 화물차 통행량과 지역 내 인구수는 양의 상관관계를 가지기 때문에 인구밀집지역에서는 화물차를 포함한 차량운행제한 검토가 필요하다. 본 연구 결과의 신뢰도를 높이기 위해서는 실제 통행량 자료를 기반으로 다중회귀모형 외 다양한 모형 추정을 통하여 추정 결과에 대한 오차를 줄여야 할 필요가 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제40권3호
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• pp.180-184
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• 2016

국제기구 및 각국의 정부는 인간의 건강 및 환경을 보호하기 위해 선박의 배기가스 규제를 엄격히 적용하고 있다. 함정은 이러한 배기가스 규제 적용 대상에서 제외되고 있지만 최근 미국, 영국 등 일부 선진국에서는 함정으로 야기되는 대기환경오염을 방지하기 위해 전기추진체계 시스템을 도입하는 등 다양한 개선 방법을 적용하고 있다. 본 연구에서는 함정용 디젤엔진의 매연 발생 문제 해결을 위해 노즐 직경을 축소 변화시키고 분사압력을 증가시켜 배기가스 발생량 측정과 오염물질조사 방법론을 이용해 저부하시 매연 문제가 개선된 것을 확인하였다. 동시에 그 영향을 유량방정식과 함정시험평가서를 통해 노즐 직경 축소 결과 연료 소비량이 감소되는 것을 확인하였다.

• 대한기계학회논문집B
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• 제31권9호
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• pp.790-798
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• 2007

An experimental study was performed to investigate the effects of mixing quality, inlet pressure, nozzle diameter on CO, NO emission and radiation characteristics in porous ceramic fiber radiant burners. Observations of combustion characteristics occurring inside the burner system which was insulated fiber mat, were investigated by measuring emission and radiation characteristics. Combustion was achieved at the firing rate of $88{\sim}99\;kcal/hr$, inlet pressure of $100{\sim}250mmH_2O$. The fiber burner exhibit significant both spectral intensity peaks in the bands at $2.5{\mu}m\;and\;4.0{\mu}m$ relatively. There is a small difference in the variable mixing tube. However spectral intensity increased with the firing rate. CO emissions were found to be strongly dependent on the operating conditions. There was a tendency that CO concentration increased as the firing rate increases. the reason for rise of CO concentration is that is becomes it the relatively rich condition. Relatively low NO emission was observed for the whole operating range. The NO concentration is maximal at the firing rate of approximately 2850 kcal/hr and an air ratio of about 1.

• 한국환경과학회지
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• 제18권10호
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• pp.1103-1114
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• 2009

In this study, the environmental behavior of malodor pollutants (MPs: $H_2S$, $CH_3SH$, DMS, and DMDS) was investigated around areas influenced by strong anthropogenic processes based on observations and modeling study (a CALPUFF dispersion model). The MP emission concentrations were measured from 8 industrial source regions (tire plants (S1-S3), waste water disposal plant (S4), and oil refinery (S5) in an urban center area and paper mill/incineration plant (S6) and livestock feedlots (S7-S8) in Ungsang area) in Yangsan city during a fall period in 2008 (21 October 2008). Overall, the most MPs emitted from the urban center area were found to affect the malodor pollution in their downwind areas during early morning (06:00 LST) and nighttime (18:00 and 21:00 LST), compared with those in the Ungsang area. For malodor intensity, the most MPs in the urban center area (especially S1 and S2) were found to be a significant contributor, whereas $CH_3SH$ and $H_2S$ in the Ungsnag area (especially S6) were the dominant contributor. The model study showed agreement in the spatial distributions of simulated MPs with those of the observations. The largest impact of MPs in the urban center area on the malodor pollution in its residential areas occurred at S1, S2, and S3 sites during nighttime, while that of MPs in the Ungsang area occurred at S6 and S8 sites. This may be caused mainly by the high MP emissions and in part by wind conditions (prevailing northeasterly winds with low wind speeds of 2-3 m/s).