소형 선박용 디젤엔진에서 엔진초기화 세팅을 통한 연소성능 및 배기배출물 개선에 관한 연구

류영현,정균식,남정길 한국마린엔지니어링학회 2019 한국마린엔지니어링학회지 Vol.43 No.7

Tugboats that sail along a coast may experience poor engine combustion performance due to frequent entry and departure and frequent change of the ship’s speed. Decrease in combustion performance may cause an increase in specific fuel consumption and an increase in harmful exhaust emissions. Consequently, the engine maintenance cycle may be shortened, and its maintenance cost may increase. An initialization method that returns a small marine diesel engine to the state of a new engine needs to be employed to improve the combustion performance and reduce exhaust emissions. This method involves adjusting the matching of the exhaust turbocharger initialization, fuel injection timing, and fuel injection amount. By using this method, it is possible to optimize the engine by considering its future load range. This study measured and diagnosed the combustion condition of a small ship (tugboat) equipped with a 4-stroke diesel engine, which is currently operated. The methods to improve combustion performance and reduce exhaust emissions were then suggested. When the engine performance was improved through engine initialization, the maximum compression pressure increased by 34.9%, maximum explosion pressure by 24.7%, indicated mean effective pressure by 10.9%, engine output by 20.0%, and specific fuel consumption by 4.2%. Additionally, the exhaust gas temperature decreased by an average of 39.2 °C. The result of exhaust emission measurement revealed that particulate matter decreased by 55.8%, carbon dioxide known as greenhouse gas by 12.5%, carbon monoxide by 74.4%, and nitrogen oxide by 4.4%. 연안을 항해하는 소형선박(Tug boat)은 잦은 입·출항과 잦은 선속 변경으로 엔진의 연소성능이 저하될 수 있다. 연소성능의 저하는 연료 소비율 증가 및 유해 배기배출물 증가의 원인이 될 수 있다. 또한 그러한 이유로 엔진정비 주기가 짧아질 수 있어 엔진정비 비용이 증가될 수 있다. 소형 선박용 디젤엔진의 연소성능 및 배기배출물을 개선하기 위하여 제시된 방안으로 엔진을 신조시의 상태로 돌려보내는 초기화 방법으로 배기 과급기 초기화 매칭, 연료분사시기 및연료분사량을 조정하는 것이며, 이 방법을 이용하여 향후 엔진의 사용부하영역을 고려한 최적화도 가능하다. 본 연구에서는 현재 운항되고 있는 4행정 디젤엔진이 탑재된 소형선박(Tug boat)의 연소상태를 계측하여 진단하였으며, 연소성능개선 및 배기배출물 저감 방안을 제시하였다. 엔진초기화를 통해 엔진성능이 개선된 후에 최고압축압력은 34.9%, 최고폭발압력은 24.7%, 도시평균유효압력은 10.9%, 엔진 출력은 20.0% 증가하였으며, 연료소비율도 4.2% 향상되었다. 또한, 배기가스 온도는 평균 39.2 ℃ 감소하는 결과를 얻을 수 있었다. 배기배출물의 계측결과, Dust(PM)는 엔진성능 개선 후에55.8% 감소하였으며 GHG(Green House Gas)로 알려진 이산화탄소는 12.5%, 일산화탄소는 74.4% 감소하였고 질소산화물도 4.4% 감소되는 결과를 얻었다.

대형 2행정 디젤엔진의 SCR 및 EGR 시스템에 의한 NOx 배출물 저감 특성에 관한 연구

배명환(Myung-whan Bae),류지호(JiHo Ryu),김성완(SeongWan Kim),박희성(Hui-seong Park) 대한기계학회 2020 大韓機械學會論文集B Vol.44 No.7

본 연구의 목적은 선박용 대형 2행정 디젤엔진에 있어서 NOX 배출물에 대한 Tier III 규제값에 따르는 EGR 시스템의 적용 가능성을 확인하는 것이다. 디젤엔진에 Miller 사이클, SCR 및 EGR 시스템을 적용하여 엔진부하에 따른 최대 연소압력, 최대 압축압력, 배기온도, 연료소비율, O₂ 및 NOX 배출물을 실험에 의해 측정하여 비교하였다. 실험 결과는 Miller 사이클을 적용한 경우, 연비는 SCR 및 EGR 시스템보다 높았고, ISO 수정식에 의한 NOX 배출물의 최종 산정값은 Tier II 규제값을 만족하였다. 또한, SCR 및 EGR 시스템을 적용하여 측정한 NOX 배출물의 ISO 수정식에 따른 산정값은 Tier III 규제값을 만족하였고, EGR 시스템에 있어서 NOX 배출물의 산정값은 SCR 시스템보다 0.4 g/kWh 더 많았지만, EGR 시스템 적용에 의해 규제값을 만족시킬 수 있음을 알았다. The purpose of this study is to identify the applicability of EGR system complying with the Tier III regulation values for NOx emissions in a marine large two-stroke diesel engine. The Miller cycle, SCR and EGR systems were applied to the diesel engine, and the maximum combustion pressure, maximum compression pressure, exhaust temperature, fuel consumption rate, and the O₂ and NOx emissions as a function of engine load in each case were experimentally measured and subsequently compared. It was concluded that the fuel economy was higher than those of SCR and EGR systems, and the final estimated NOx emissions bases on the modified ISO formula satisfied the Tier II regulation values when the Miller cycle was applied. In addition, it was found that the estimated values of NOx emissions measured by applying the SCR and EGR systems corresponding to the modified ISO formula met in the Tier III regulation values, and this value of NOx emissions by EGR system was 0.4 g/kWh more than that of SCR system, but the regulation value could be met by the application of EGR system.

가솔린엔진 운행자동차 배기 배출물에 미치는 튜닝 흡기 및 배기 시스템의 효과에 관한 연구

배명환,구영진,박희성 대한기계학회 2019 大韓機械學會論文集B Vol.43 No.5

The purpose of this study is to obtain the basic data of engine tuning inspection by confirming the working possibility of effective engine tuning and identifying the characteristics of tuned engine that are no safety and environmental problems in a driving car of gasoline engine. The actual driving car with a four-cycle, four-cylinder DOHC, turbo-intercooler, water-cooled gasoline engine operating under four types of non-tuning, and tuning 2-1, 2-2 and 2-3 was applied to investigate the effects of tuned engine on the characteristics of excess air ratio and exhaust emissions by the low speed idle and acceleration simulation mode inspections. The tuned parts of gasoline engine in a driving car include the intake manifold, intake pipe, air filter, exhaust manifold, exhaust pipe and silencer. It was found that the measured values of CO emission, THC emissions and excess air ratio by the low speed idle inspection method, and NOX, CO and THC emissions by the acceleration simulation mode inspection method for the gasoline non-tuned and tuned engines of driving car were all satisfied with the inspection standard without any environmental problems. However, the measured values of tuned engine were greater than those of non-tuned engine. 본 연구의 목적은 가솔린엔진 운행자동차에 있어서 안전과 환경에 문제가 없는 효과적인 엔진튜닝의 작업가능성을 확인하고, 튜닝엔진의 특징을 파악하여 엔진튜닝 검사의 기초자료를 확보하는 것이다. 저속 공회전 및 정속 모드 검사에 의해 공기과잉률 및 배기 배출물을 측정해 튜닝엔진의 효과를 조사하기 위하여 4행정, 4기통 DOHC, 터보 인터쿨러, 수냉 가솔린엔진에 대한 비튜닝 및 튜닝 2-1, 2-2, 2-3의 4종류를 실제 운행자동차에 적용하였다. 운행자동차에 대한 가솔린엔진의 튜닝부분은 흡기 다기관, 흡기 파이프, 공기필터, 배기 다기관, 배기 파이프 및 소음기이다. 운행자동차 가솔린 비튜닝 및 튜닝 엔진에 대해 저속 공회전 검사방법에 의한 CO 배출물, THC 배출물 및 공기과잉률과 정속모드 검사방법에 의한 NOX, CO 및 THC 배출물 측정값은 모두 환경에 대한 문제가 없이 검사기준에 만족하였지만, 이 측정값들은 튜닝엔진의 경우가 비튜닝엔진보다 더 증가되었음을 알았다.

FGR 시스템 동력 플랜트 보일러의 성능 및 배기 배출물에 미치는 재순환 배기의 영향에 관한 연구

배명환(Myung-whan Bae),정광호(Kwong-ho Jung),박성범(Sung-bum Park) 대한기계학회 2016 大韓機械學會論文集B Vol.40 No.4

자연순환식 압입 송풍식 수관보일러에 FGR시스템을 설치하여 보일러 부하 및 공기량 댐퍼개도를 파라미터로 해서 FGR률에 따른 성능 및 배기 배출물에 미치는 재순환 배기의 영향을 조사하였다. 본 연구의 목적은 NOx 배출물을 저감시키기 위하여 동력플랜트 보일러에 FGR시스템을 적용하는 것이다. 연소를 활성화시키기 위해 0 ∼ 20%의 연소용 공기를 화염 내에 공급한다. 공기상자 상부에 설치된 2단 연소시스템의 흡입댐퍼를 0° ∼ 90° 사이에서 레버를 조작하여 열면, 버너로 공급되는 연소용 공기가 변화된다. 증발률당의 연료소비율은 FGR률의 증가에 따라 증가 혹은 감소의 명확한 경향을 나타내지 않았고, 동일 공기량 댐퍼개도에서는 FGR률이 증가할수록, 또한, 보일러 부하가 감소할수록 NOx 배출물이 감소되었다. 매연 배출물은 전기 집진기에서 86.7%의 포집효율로 매연이 제거되었기 때문에, 보일러 부하, 공기량 댐퍼 개도 및 FGR률의 운전조건에 관계없이 극소량의 매연이 배출되었다. The effect of recirculated exhaust gas on performance and exhaust emissions with FGR rate are investigated by using a natural circulation, pressurized draft and water tube boiler with FGR system operating at several boiler loads and over fire air damper openings. The purpose of this study is to apply the FGR system to a power plant boiler for reducing NOx emissions. To activate the combustion, the OFA with 0 to 20% is supplied into the flame. When the suction damper of two stage combustion system installed in the upper side of wind box is opened by handling the lever between 0° and 90°, also, the combustion air supplied to burner is changed. It is found that the fuel consumption rate per evaporation rate did not show an obvious tendency to increase or decrease with rising the FGR rate, and NOx emissions at the same OFA damper opening are decreased, as FGR rates are elevated and boiler loads are dropped. While a trace amount of soot is emitted without regard to the operation conditions of boiler load, OFA damper opening and FGR rate, because soot emissions are eliminated by the electrostatic precipitator with a collecting efficiency of 86.7%.

직접분사식 가솔린엔진에서 운전조건에 따른 바이오에탄올의 연소 및 배기배출물 특성

윤승현(Seung Hyun Yoon),박수한(Su Han Park) 대한기계학회 2015 大韓機械學會論文集B Vol.39 No.7

본 연구는 직접분사식 가솔린엔진에서 공기 과잉률 및 바이오에탄올-가솔린 혼합연료의 혼합비에 따른 연소특성과 배기배출물 특성을 실험적으로 규명한 것이다. 다양한 공기 과잉률 및 혼합비 조건에서 실험을 수행하였으며, 연소실 압력, 열발생률, 연료소비율 등을 통해 연소특성을 분석하였으며, 배기 배출물 특성은 미연탄화수소(HC), 일산화탄소(CO), 질소산화물(NOx ) 분석을 통해 확인하였다. 혼합연료의 실험결과는 100% 가솔린 및 바이오에탄올 실험결과와 비교하였다. 실험결과 최고연소압력과 열발생률, 제동연료소비율은 혼합비의 증가에 따라 증가하였으며, CO, HC, NOx와 같은 배기배출물은 바이오에탄올 혼합비율이 증가함에 따라 감소하였다. 혼합연료의 배기배출물 수준은 가솔린 보다 낮게 나타났다. In this study, the combustion and exhaust emission characteristics in a gasoline direct injection engine with variations of the bio-ethanol-gasoline blending ratio and the excess air factor were investigated. To investigate the effects of the excess air factor and the bio-ethanol blends with gasoline, combustion characteristics such as the in-cylinder combustion pressure, rate of heat release (ROHR), and the fuel consumption rate were analyzed. The reduction of exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), and nitrogen oxides (NOx) were compared with those of gasoline fuel with various excess air factors. The results showed that the peak combustion pressure and ROHR of bio-ethanol blends were slightly higher and were increased as bio-ethanol blending ratio is increased. Brake specific fuel consumption increased for a higher bio-ethanol blending ratio. The exhaust emissions decreased as the bio-ethanol blending ratio increased under all experimental conditions. The exhaust emissions of bio-ethanol fuels were lower than those of gasoline.

직접분사식 농용 디젤기관에서 함산소연료의 배기 배출 특성

강형수 ( Hyoung-soo Kang ),윤상진 ( Sang-jin Yun ),조기현 ( Ki-hyon Cho ) 한국고등직업교육학회 2002 한국고등직업교육학회논문집 Vol.3 No.4

Diesel-powered vehicles are popular for heavy-load transportation because their fuel efficiency is higher than that of gasoline-powered. Although diesel engines provide convenience in our daily life, their emission smell bad and contain many type of toxic air pollutants. Improvements in fuel properties have become essential for emission reduction as well as for optimization of directly-related design factors and exhaust gas aftertreatment. In this study, the potential possibility of oxygenated fuel such as ethylene glycol mono-n-butyl ether(EGBE) was investigated for the sake of smoke reduction from diesel engine. Because EGBE include oxygen content approximately 27.1%, it is a kind of effective oxygenated fuel that the smoke emission of EGBE is reduced remarkably in comparison with commercial diesel fuel, that is, it can supply oxygen component sufficient at high load and speed in diesel engine.

인터페이스 회로를 적용한 디젤기관의 배출가스특성에 관한 실험적 연구

한영출,김대열,백두성 한국공작기계학회 2003 한국생산제조학회지 Vol.12 No.6

In order to collect the engine performance data and determine optimum engine conditions, engine performance test based on interface unit were tested. This paper was carried out that engine' performance was developed using interface unit between personal computer and diesel engine. The results of the study are summarized as follows: Interface unit was developed. By using PAL, Simulation was carried in order to logic's inspection. From this test, NOx were decreased, otherwise PM were increased. By using EGR system, PM were increased by twice in the high load ranges, it was not seen to come into effect in the low load ranges. This system was tested D13 mode, the results were decreased more than 50% in the NOx emission.

선박배출 배기냉각을 통한 유해 배기배출물 저감에 관한 기초 실험 연구

신동길,김영민,류영현 해양환경안전학회 2022 해양환경안전학회 학술발표대회 논문집 Vol.2022 No.06

물 혼합 연료를 사용한 디젤엔진의 EGR시스템에 의한 NO_x와 Soot의 배출특성 연구

박태인 慶尙大學校 工科大學 機械設計學科 1997 WORKSHOP 자료집 Vol.1997 No.1

Over the past years, many research works have been carried out to investigate the factors governing the performance of diesel, engine. The area of study has been focused on reducing NOx and soot, because there are many difficulties to reduce both at once in diesel engine. One of the efforts is developing EGR technology to reduce NOx emission. That is very effective on reducing NOx, but increases other emissions and makes economy worse. In order to solve the problem, EGR is employed with water emulsified fuel and tested in this experimental study. Emusified fuel is produced by centrifugal mixer and the amount of water is controlled by water injector and pulse generator. The results show that both NOx and smke emissions are reduced with a great degree simultaneously.

직접분사식 디젤기관에서 메탄올 혼합연료의 배기 배출물에 관한 연구

서정주,왕우경,김상암 여수대학교 2001 論文集 Vol.16 No.-

In this study, the fuel injection system of a DI diesel engine was modified slightly with installing two agitators and a F.O supply pump to use the methanol-blended fuel. The emission concentrations were compared with the case of diesel oil and the methanol-blended fuel in a DI diesel engine. The results are as follows : The concentrations of NOx and HC in exhaust emissions were lower than those of diesel oil as blending ratio of methanol increased, but the concentration of CO was higher slightly. As it was used the methanol-blended fuel of 10%∼20%, the exhaust emissions of NOx and HC were improved no significant difference of the engine performance in comparison with diesel oil. As the load was increased, the concentration of CO2 in exhaust emissions was high and that of O2 was low, and concentration of those in exhaust emissions was no significant difference among the fuels at constant loads.