• 한국자동차공학회논문집
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• 제15권2호
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• pp.58-64
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• 2007

As the concerns regarding global worming were increased, the pressure of greenhouse gas(GHG) emission reduction on mobile source was also increased. Carbon dioxides contribute over 90% of total GHG emission and the mobile source occupies about 20% of this $CO_2$ emission. Therefore automotive exhaust is suspected to be one of the major reasons of the rapid increase in greenhouse effect gases in ambient air. In this study, in order to investigate $CO_2$ emission characteristics from gasoline passenger cars(PC), which is the most dominant vehicle type in Korea, 106 vehicles were tested on the chassis dynamometer. $CO_2$ emissions and fuel efficiency were measured. The emission characteristics by displacement, gross vehicle weight, vehicle speed and CVS-75/vehicle speed mode were discussed. Test modes were vehicle speed modes and CVS-75 mode that have been used to develop emission factors and to regulate for light-duty vehicle in Korea. It was found that $CO_2$ emissions showed higher large displacement, heavy gross vehicle weight, low vehicle speed and CVS-75 mode than small displacement, light gross vehicle weight, high vehicle speed and vehicle speed mode, respectively. From these results, correlation between $CO_2$ emission and fuel efficiency was also determined. The results of this study will contribute to domestic greenhouse gas emissions calculation and making the national policy for climate change.

• 한국대기환경학회지
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• 제22권4호
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• pp.451-458
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• 2006

Automotive exhaust is suspected to be one of the major reasons of the rapid increase in greenhouse effect gases in ambient air. As the concerns regarding global worming were increased, the pressure on mobile source greenhouse gas (GHG) emission were also increased. Carbon Dioxides contribute over 90% of total GHG emission and the mobile source occupies about 20% of this $CO_2$ emission. In this study, in order to investigate $CO_2$ emission characteristics from gasoline and LPG passenger cars (PC), which is the most dominant vehicle type in Korea, 53 vehicles were tested on the chassis dynamometer. $CO_2$ emissions and fuel consumption efficiency were measured. The emission characteristics by fuel type, model year, mileage, vehicle speed and transmission type were also discussed. Test modes used in this study were NIER 10 modes and CVS-75 mode, which have been used for developing emission factors and testing new vehicles respectively. The results of this study showed that the main factors which have significant influences on the $CO_2$ emissions are fuel type, transmission type, displacement of vehicle and mileage. The correlation between $CO_2$ emission and FE was also determined by comparing $CO_2$ emission and fuel consumption efficiency. The overall results of this study will greatly contribute to domestic greenhouse gas emissions calculation and designing national strategies for climate change.

• 생물환경조절학회지
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• 제12권3호
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• pp.107-113
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• 2003

본 연구에서는 온실의 온풍식 난방시스템 연통에 장착할 수 있는 폐열 회수기의 성능 개선을 목적으로 기 설계된 세 가지 열교환 장치와 기존의 장치에서 열교환 면적과 파이프의 두께 및 공기흐름 방향을 개량한 새 열교환 장치에 대해 열회수 성능을 실험적으로 비교 분석하였다. 그 결과 기존의 열 교환장치인 A형, B형 및 C형의 열회수 성능은 동일 송풍전입에서 각각 42.2%, 40.6% 및 54.4% 정도였으나 , 새로 개량된 D형은 69.2%로써 가장 현저히 높게 나타났다. 그러나 열회수용 공기의 흐름방향 변화에 따른 열회수 성능 개선효과 (A형 대비 B형)는 없는 것으로 나타나 적정 송풍기 용량이라면 직선형이 공기의 흐름방향 180${\circ}C$ 굴절시키는 헤어핀형보다 효과적인 것으로 판단된다. 결국 열회수 성능은 열회수 시스템의 열교환 면적과 열교환 파이프의 두께 및 풍속에 크게 좌우되는 것으로 나타났다. 따라서, 열교환 파이프의 내구성 등 을 고려하여 기능한 한 범위 내에서 열 교환면적을 증대시키거나 열교환 파이프의 두께를 앓게 하고 풍속을 증대시키는 것이 열회수 성능 개선효과와 직결됨을 알 수 있었다. 그리고 송풍기 용량이 필요이상으로 큰 경우, 소비전력이 많게 되는 등의 문제가 있기 때문에 적정용량 및 제품의 안정성을 고려하여 선택해야 할 것으로 판단되었다.

• 터널과지하공간
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• 제28권6호
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• pp.609-619
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• 2018

주선풍기가 설치된 통기수갱이 굴착된 국내 석회석 광산에서 수행한 통기수갱의 통기효과 분석결과 자연통기 및 기계통기 효과가 뚜렷하게 나타났다. 수갱을 통하여 입기되는 자연통기량은 최대 $11.7m^3/s$이었으며 갱내 공기온도의 측정에 의하여 비교적 정확한 정량적 예측이 가능하였다. 선풍기 가동에 의한 배기 통기량은 $20.3{\sim}24.8m^3/s$로 통기량의 변동은 갱도내 장비의 이동에 의한 통기특성곡선의 상향이동에 따른 선풍기 운전점의 변화에 의한 결과이므로 통기저항의 저감 노력이 요구된다. 갱구로부터 수갱까지 총 1912 m 갱도내 난류확산계수는 $15m^2/s$, $18m^2/s$로 나타나 오염물질은 기류보다 상대적으로 빨리 확산되므로 공기질 제어를 위하여 신속한 배기가 요구된다. 따라서 통기용 수갱은 급격히 심부화 및 대형화되고 있는 국내석회석광산의 지속적 개발을 위한 필수적 갱내 환경제어 시설로 권장되어야할 것으로 판단된다.

• International Journal of Automotive Technology
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• 제6권1호
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• pp.15-21
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• 2005

The purpose of this paper is to experimentally investigate the engine pollutant emissions and combustion characteristics of diesel engine fueled with ethanol-diesel blended fuel (bio-diesohol). The experiments were performed on a single-cylinder DI diesel engine. Two blend fuels were consisted of $15\%$ ethanol, $83.5\%$ diesel and $1.5\%$ solublizer (by volume) were evaluated: one without cetane improver (E15-D) and one with a cetane improver (E15-D+CN improver). The engine performance parameters and emissions including fuel consumption, exhaust temperature, lubricating oil temperature, Bosch smoke number, CO, NOx, and THC were measured, and compared to the baseline diesel fuel. In order to gain insight into the combustion characteristics of bio-diesohol blends, the engine combustion processes for blended fuels and diesel fuel were observed using an Engine Video System (AVL 513). The results showed that the brake specific fuel consumption (BSFC) increased at overall engine operating conditions, but it is worth noting that the brake thermal efficiency (BTE) increased by up to $1-2.3\%$ with two blends when compared to diesel fuel. It is found that the engine fueled with ethanol-diesel blend fuels has higher emissions of THC, lower emissions of CO, NOx, and smoke. And the results also indicated that the cetane improver has positive effects on CO and NOx emissions, but negative effect on THC emission. Based on engine combustion visualization, it is found that ignition delay increased, combustion duration and the luminosity of flame decreased for the diesohol blends. The combustion is improved when the CN improver was added to the blend fuel.

• 한국수소및신에너지학회논문집
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• 제25권5호
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• pp.533-540
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• 2014

The remanufacturing industry for automotive parts is a major issue which affects the environment protection and CO2 reduction throughout the world. Beside this, remanufacturing technologies of worn-out diesel engines have been developing to make as close to new as possible. In this study, the characteristics of the engine-power output and exhaust emissions of remanufactured diesel engine by hydrogen enrichment are evaluated by measuring the engine and vehicle test. Moreover, with worn-out diesel engine and first generation common-rail engine, we compared by testing their characteristics, resulting in the restoration of engine-power output more than 93%, as well as marvelously reduces the THC and NOx emission. At a guess, high pressure injection of diesel increases fuel atomization characteristics with excellence combustion efficiency, resulting in reduction of THC emission. Also, rapid cooling of EGR decreases combustion temperature, resulting in reduction of NOx emission. Consequently, these remanufacturing for diesel engine enables worn-out diesel engine to have restoration to the original state. Simultaneously achieved 2 goals called that CO2 emission reduction and protection of environment by remanufacturing engine.

• 한국산업보건학회지
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• 제18권3호
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• pp.189-203
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• 2008

Cylindrical bag filter system with pulse jet cleaning has been the most common device to control particle laden exhaust gas from the various industrial processes. But, it has many shortcomings due to particle reattachment and frequent bag rupture. In recent years, rectangular type bag filter system has been developed to overcome the problems associated with the cylindrical system. However, not many studies about the rectangular system were not done, compared to the cylindrical system. In this study, the optimum pulse jet cleaning conditions were thus tested by the series of experiments. The factors tested in this study are pulse distance, pulse pressure, pulse duration, the number of holes for pulsing and bag materials. A single bag ($1,500mmL{\times}50mmW{\times}300mmH$) system and a multi-bags (3 bags in a row) were tested separately. The highest removal efficiency with a single bag system was found at the conditions with pulse distance of 10cm, pulse pressure of $3kg/cm^2$, pulse duration of 0.3s, pulse jet number of 6 and Polyester bag. With the multi-bags system, the best cleaning conditions were found at the bag interval of 20cm with the simultaneous pulsing and the bag interval of 15cm with the serial pulsing.

• 유공압시스템학회논문집
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• 제4권1호
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• pp.18-24
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• 2007

The continuously variable transmission (CVT) of which speed ratio can change continuously in a fixed range has the benefits of low fuel consumption and exhaust gas because it enables the engine of a vehicle to operate in a high efficiency range regardless of vehicle speed. The speed ratio of belt type CVT is controlled by adjusting line pressure. The one of the line pressure control methods, mechanical-hydraulic control is usually adopting VDT's control method, in which the secondary solenoid valve has two functions both a regulator and a line pressure controller. However, this control method could not show the high performance of CVT with optimal driving capability because of the limitation of simple control algorithm, and it could not gain market share sufficiently in spite of the advantage of CVT with low fuel consumption. On the other hand, the electro-hydraulic control method gives the enhancement of power performance and low fuel consumption by implementing various driving mode using the proportional control or PWM control. The key of CVT technique is to develop a control algorithm of the electro-hydraulic solenoid valve in order to implement the speed ratio efficiently. In this paper, the line pressure control algorithm is proposed and the hydraulic system is controlled using metal belt type CVT test rig and the embedded ECU platform.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.244.1-244.1
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• 2010

Bio energy development by using Low Calorific Gas Turbine(LCGT) has been developed for New & Renewable energy source for next generation power system, low fuel and operating cost method by using the renewable energy source in landfill gas (LFG), Food Waste, water waste and Livestock biogas. Low calorific fuel purification by pretreatment system and carbon dioxide fixation by green house system are very important design target for evaluate optimum applications for bio energy. Main problems and accidents of Low Calorific Gas Turbine system was derived from bio fuel condition such as hydro sulfide concentration, siloxane level, moisture concentration and so on. Even if the quality of the bio fuel is not better than natural gas, LCGT system has the various fuel range and environmental friendly power system. The mechanical characterisitics of LCGT system is a high total efficiency (>70%), wide range of output power (30kW - 30MW class) and very clean emmission from power system (low NOx). Also, we can use co-generation system. A green house designed for four different carbon dioxide concentration from ambient air to 2000 ppm by utilizing the exhaust gas and hot water from LCGT system. We look forward to contribute the policy for Renewable Portfolio Standards(RPS) by using LCGT power system.

• 청정기술
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• 제7권1호
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• pp.65-74
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• 2001

본 연구는 디젤엔진에서 배출되는 NOx환원용 촉매로서 산화반응에서 우수한 활성을 나타내고 있는 페롭스카이트상의 $LaCoO_3$을 sol-gel 공정을 이용하여 촉매코팅용액을 제조한 후, 이를 기존의 dip-coating방법보다 코팅시간, 코팅량, NO-CO 산화 환원 반응에 있어서 경제적이고 효율적인 modified dip-coating방법을 이용하여 촉매코팅필터를 제조하고 이를 후처리장치에 부착함으로써 디젤엔진에서 배출되는 배가스를 효과적으로 제거시키고자 한다. 실험결과, modified dip-coating방법이 기존의 dip-coating방법에 비해서 코팅에 소요되는 용액량이 8.3배 코팅시간 83.3배 단축되었으며, 코팅량은 2~3배정도 커지고, NO-CO 산화 환원 반응성도 1.1~1.8배 가량 증가하였다. 그리고 코팅점도는 $0.006202kg{\cdot}m/sec$을 이용하여 코팅횟수 2회, 코팅량은 88.56mg/g에서 우수한 반응을 보였다. 또한 세라믹 필터의 셀수에 있어서는 200 CPSI가 적절함을 확인할 수 있다.