CNG/Diesel 이종연료용 엔진의 성능 및 배출가스 특성에 대한 연구

임옥택(Ock Taeck Lim) 대한기계학회 2011 大韓機械學會論文集B Vol.35 No.9

CNG/diesel dual-fuel 엔진은 CNG 를 주 연료로 사용하고 소량의 디젤을 착화제로서 실린더 내에 분사한다. 본 연구에서는 기존의 디젤엔진을 커먼레일직접분사(CRDI)를 통하여 고압으로 디젤을 분사하고, 예혼합을 위하여 CNG 를 흡기포트에 분사하는 CNG/diesel dual-fuel 엔진으로 개조하였다. CNG/diesel dualfuel engine 은 기존의 디젤엔진과 동등한 수준의 토크 및 출력성능을 나타내었다. 또한, CNG 대체율은 CNG/diesel dual-fuel 엔진의 전체 운전영역에 대하여 89% 이상을 만족시켰다. Dual-fuel 엔진의 PM 배출농도는 디젤엔진보다 94% 더 낮게 나타났지만, NOx 배출농도는 더 높게 나타났다. In a CNG/diesel dual-fuel engine, CNG is used as the main fuel and a small amount of diesel is injected into the cylinder to provide ignition priming. In this study, a remodeling of the existing diesel engine into a CNG/diesel dual-fuel engine is proposed. In this engine, diesel is injected at a high pressure by common rail direct injection (CRDI) and CNG is injected at the intake port for premixing. The CNG/diesel dual-fuel engine had an equally satisfactory coordinate torque and power as the conventional diesel engine. Moreover, the CNG alternation rate is over 89% throughout the operating range of the CNG/diesel dual-fuel engine. PM emission by the dual-fuel engine is 94% lower than that by the diesel engine; however, NOx emission by the dual-fuel engine is higher than that by the diesel engine.

천연가스-디젤 혼소엔진에서 연료 공급방식에 따른 엔진 성능 및 배기 특성

유동규 ( Donggyu Yu ),표영덕 ( Youngdug Pyo ),우영민 ( Youngmin Woo ),임옥택 ( Octeck Lim ),장진영 ( Jinyoung Jang ) 한국분무공학회 2024 한국분무공학회지 Vol.29 No.4

Due to the global energy shortage and climate change, emission regulations are becoming stricter, and internal combustion engines are evolving to reduce emissions through the use of eco-friendly alternative fuels. Accordingly, this study focused on improving engine performance and exhaust characteristics through the dual-fuel operation of diesel engines. The subject of thise study was a 4-cylinder HMC D4GA CRDI diesel engine, which was modified to operate in dual-fuel mode with natural gas. The experiment utilized the original ECU(Engine Control Unit) and DF(Dual Fuel) ECU to control diesel injection amounts. Natural gas was supplied using the proportional control valve method and the SPI(Single Point Injection) method, managed by the DF ECU. The dual-fuel engine maintained more than 95% of the output of the original diesel engine(maximum 95 kW), and the knocking issue was mitigated through low pressure exhaust gas recirculation(LP EGR) control. When the original ECU was used, the precision of diesel injection control was insufficient. This resulted in a higherthan- target natural gas ratio, which decreased engine efficiency and lowered exhaust gas temperatures. In contrast, when the DF ECU was used to precisely control both diesel and natural gas injection quantities, engine efficiency and exhaust emission characteristics were improved. Notably, the highest engine efficiency and lowest THC emissions were achieved under conditions where diesel injection timing was optimized using the DF ECU, and NOx emissions were also reduced. These findings confirm that diesel injection timing control via the DF ECU is effective in optimizing the performance and exhaust characteristics of a dual-fuel engine.

기계식 디젤엔진의 디젤-천연가스 혼소화를 통한 디젤 대체율 향상 연구

심주현(JuHyen Sim),곽용환(Yonghwan Kwak),고춘식(Chunsik Ko),이욱재(Okjae Lee),이상민(Sangmin Lee),이창언(Chang-Eon Lee) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

An experimental study was performed to provide the effect of PM reduction and the improvement of diesel alternative ratio utilizing diesel-natural gas dual-fuel combustion mode in a retrofit 3.4-liter diesel engine. In order to achieve the same power as the original diesel engine, engine control unit (ECU) of the dual-fuel engine was calibrated. During this calibration, the amount of diesel fuel injection was fixed same as the amount in the idle state for all engine load conditions and liquefied natural gas (LNG) fuel injection was adjusted to increase power based on the power in idling state. LNG fuel was injected by a single point injection at the inlet of intake air manifold. As a result, diesel alternative ratio was improved in overall through making up the characteristic of lower diesel fuel consumption in comparison with mechanical diesel engine. Diesel alternative ratio was calculated from the experimental data acquired from full load test. It was found that the maximum value of diesel alternative ratio was about 96%. Finally PM emission experiment was performed in C1-8 mode cycle and it was shown PM emission was extremely reduced down to 7.42*10<SUP>-7</SUP> g/kWh comparing with mechanical diesel engine. From these results we believe our dual-fuel engine could meet Tier-4 regulations.

LPG를 이용한 동력경운기 디젤기관의 연소성능

이승규,김성태,조기현 경상대학교 농업생명과학연구원 2001 농업생명과학연구 Vol.35 No.-

농용LPG기관의 개발을 목적으로 단기통, 4행정 농용디젤기관과 이를 개량한 LPG기관을 사용하여, 기관의 성능시험을 실시하고, LPG기관을 탑재한 동력경운기를 이용하여 포장실험을 수행하였다. 성능시험은 기관의 회전수를 1200 rpm에서 2200 rpm까지 200 rpm씩 증가시키면서 실시하였고, 포장시험은 기관의 정격출력으로 실시하였다. 그 결과를 요약하면 다음과 같다. 디젤기관의 출력은 5.4 kW에서 9.9 kW로, 또 LPG기관의 출력은 5.5 kW에서 9.6 kW로 각각 증가하였으며 두 기관의 출력의 차이는 크지 않았다. 디젤기관의 연료소비율은 297 g/kWㆍh에서 279 g/kWㆍh으로 점감하다 315 g/kWㆍh까지 증가하였다. 또 LPG기관의 경우에는 320 g/kWㆍh에서 285 g/kWㆍh로 점감하다 330 g/kWㆍh까지 증가하였으며, 디젤기관에서의 연료소비율이 1.6-8.6% 만큼 낮게 나타났다. 디젤기관의 배기가스의 온도는 510℃에서 614℃로, 또 LPG기관에서의 배기가스 온도는 495℃에서 608℃로 각각 증가하였으며, 디젤기관에서의 배기가스의 온도가 10-18℃ 만큼 높게 나타났다. HC배출농도는 디젤기관의 경우 17 ppm에서 8 ppm으로 점감하다 16 ppm으로 증가하는 등, 낮은 HC배출농도를 보인 반면 LPG기관의 경우에는 250 ppm에서 100 ppm으로 급감하다가 125 ppm까지로 증가하였으며, LPG기관에서의 HC배출농도가 디젤기관의 6.8-15.7배로 높게 나타났다. CO비출농도는 두 기관 모두에서 1% 미만으로 낮게 나타났으며, 디젤기관의 경우 LPG기관에 비해 28.0-90.5% 만큼 낮게 나타났다. 디젤기관에서의 NOx배출농도는 410 ppm에서 730 ppm으로 증가하다가 650 ppm까지로 감소하였고, LPG기관에서는 300 ppm에서 570 ppm으로 증가하다가 540 ppm으로 감소하였으며, 디젤기관에서의 NOx배출농도가 16.8-33.3% 만큼 더 높게 나타났다. 디젤기관에서의 매연 배출농도는 75%에서 90%의 높은 범위에서, 또 LPG기관에서는 25%에서 35%의 낮은 범위에서 각각 증가하였으며, 디젤기관의 매연배출농도가 LPG기관에 비해 61.1-66.7% 만큼 높게 나타났다. LPG기관을 탑재한 동력경운기를 이용한 포장실험 결과, 기관의 회전수변동이 디젤기관과 유사하게 나타났으며, 시간당 1ℓ의 LPG로 포장작업이 가능하였다. NOx와 매연의 발생은 디젤기관에 비해 훨씬 적었다. In order to develop an engine for power tillers using the liquefied petroleum gas(LPG), a conventional diesel engine for power tillers was modified to a LPG using engine. Combustion performances of the experimental LPG engine and the diesel engine were tested at various engine speeds. And actual field tests for the engine as a power source of a power tiller were performed to analyze performance of the engine. Brake horse power, temperature of the exhaust gas and the smoke of both engines increased as the engine speed was increased. At the engine speed of 1800 rpm, it was observed that fuel consumption rate and HC concentration in the exhaust gas were lowest while NOx concentration was highest. The brake horse power of the LPG engine showed nearly same value as that of diesel engine. CO concentration of both engines showed below 1%. The exhaust gas temperature, the concentration of NOx and the smoke in the exhaust gas of the LPG engine showed lower values than that of the diesel engine. However, the fuel consumption rate and the HC concentration of the LPG engine were higher than that of the diesel engine. In field test, the LPG engine and the conventional diesel engine showed similar plowing performances. However, the LPG engine installed power tiller showed lower NOx and smoke values compared to those of the diesel engine.

500Ps급 상용차량 디젤엔진을 이용한 선박용 디젤엔진 개발 연구

심한섭(Han-Sub Sim) 한국기계가공학회 2013 한국기계가공학회지 Vol.12 No.6

This study was carried out to develop a diesel engine for marine propulsion. This marine diesel engine was developed based on a 500Ps vehicle diesel engine. Many main parts, such as the intercooler, radiator, and engine controller were designed for the marine diesel engine. The intercooler was designed to be of sea water cooling type; inlet air is cooled by sea water. Engine coolant is cooled by sea water in the radiator too. The water cooling heat exchanger has high cooling performance. In the cooling system, consists of the intercooler and the radiator, the sea water passes through the intercooler and then the radiator, in sequence. This process is very effective compared to the reverse method in which sea water passes through the radiator and then the intercooler, in sequence. The control performance of the engine controller and the fuel injection rate were improved using an engine speed controller. This system was tested on an engine dynamometer and an exhaust gas analyzer using the marine diesel engine test method. Test results show that the 500Ps marine diesel engine satisfied the IMO NOx regulations; Tier Ⅱ.

Performance and emission characteristics of a DI diesel engine operated with diesel/DEE blended fuel

Lee, Seokhwan,Kim, Tae Young Elsevier 2017 Applied thermal engineering Vol.121 No.-

<P><B>Abstract</B></P> <P>Diethyl ether (DEE) has long been known as a promising renewable fuel to be used in diesel engines due to its exceptional cetane number, reasonable energy density, high oxygen content, low auto-ignition temperature and high volatility. In this study, an experimental investigation was carried out to evaluate the effects of blending DEE with diesel on the performance, gas and particle emissions and combustion characteristics of a diesel engine. The blending percentages of DEE in the DEE/diesel blended fuel were set to 10, 25 and 50% by mass.</P> <P>Experimental results showed that highly stable engine operation was possible for blended fuels, and the fuel conversion efficiency was comparable to that of pure diesel. The combustion of DEE blended fuels produced less hydrocarbon (HC) and carbon monoxide (CO) emissions than diesel combustion over the entire engine load range. Particulate matter (PM) also decreased for blended fuels due to the high oxygen content of DEE. However, nitrogen oxides (NOx) from the blended fuels were higher than that of diesel over the entire engine load range of indicated mean effective pressures (IMEP) 0.2–0.8MPa due to the shorter ignition delay and high oxygen content.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We experimentally investigated the performance and emissions of a DI diesel engine. </LI> <LI> A diesel engine was operated with DEE/diesel blended fuel. </LI> <LI> Stable engine operation was possible for a wide range of loads up to 50% DEE. </LI> <LI> PM emissions significantly decreased due to the oxygen content in DEE. </LI> <LI> DEE is a promising alternative fuel to diesel. </LI> </UL> </P>

목질 열분해유의 디젤 엔진 적용성 연구

이석환 ( Seok Hwan Lee ),박준혁 ( Jun Hyuk Park ),임기훈 ( Gi Hun Lim ),최영 ( Young Choi ),우세종 ( Se Jong Woo ),강건용 ( Kern Yong Kang ) 한국분무공학회 2011 한국분무공학회지 Vol.16 No.3

Fast pyrolysis of biomass is one of the most promising technologies for converting biomass to liquid fuels. The pyrolysis oil, also known as the bio crude oil (BCO), have been regarded as an alternative fuel for petroleum fuels to be used in diesel engine. However, the use of BCO in diesel engine requires modifications due to low energy density, high water contents, low acidity, and high viscosity of the BCO. One of the easiest way to adopt BCO to diesel engine without modifications is the use of BCO/diesel emulsions. In this study, a diesel engine operated with diesel, bio diesel (BD), and BCO/diesel emulsion was experimentally investigated. Performance and emission characteristics of a diesel engine fuelled by BCO/diesel emulsion were examined. Results showed that stable engine operation was possible with emulsion and engine output power was comparable to diesel and bio diesel operation. Long term validation of adopting BCO in diesel engine is still needed because the oil is acid, with consequent problems of corrosion especially in the injection system.

MORPHOLOGY AND OXIDATION KINETICS OF CI ENGINE’S BIODIESEL PARTICULATE MATTERS ON CORDIERITE DIESEL PARTICULATE FILTERS USING TGA

P. KARIN,J. BOONSAKDA,K. SIRICHOLATHUM,E. SAENKHUMVONG,C. CHAROENPHONPHANICH,K. HANAMURA 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.1

The impact of small compression ignition (CI) engine operation conditions and fuel properties on diesel and biodiesel particulate matters (PMs) quantity using opacity smoke meter is investigated. The biodiesel engine’s PMs are around a half of diesel engine PMs under the same engine operation conditions. Morphology of both engine’s PMs are also studied using a Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and image processing method. The average primary nanoparticle sizes of diesel and biodiesel engine’s PMs are approximately 34 nm and 32 nm, respectively. The result shows that engine operation condition and fuel property are strongly impact on the quantity and size distribution of primary nanoparticles emission. PM oxidation kinetics on conventional cordierite Diesel Particulate Filters (DPFs) powders by Thermo-gravimetric analysis (TGA) is also successfully studied. The calculated apparent activation energies of biodiesel engine’s PM oxidation on conventional cordierite DPFs powders are lower than that of diesel engine’s PM and carbon black because of unburned oxygenated molecule. The calculated apparent activation energy of biodiesel engine’s PM and diesel engine’s PM oxidize on conventional cordierite DPFs powders with pure air are in the range of 109 ~ 131 kJ/mole and 117 ~ 130 kJ/mole, respectively. It might be expected that smaller primary nanoparticle size of biodiesel engine’s PMs and biooxygenate unburned hydrocarbon can promote more PM oxidation rate during vehicle’s DPF regeneration process.

디젤-열분해유 유상액을 사용하는 직접분사식 디젤 엔진의 엔진성능 및 배기특성에 관한 연구

이석환 ( Seok Hwan Lee ),김호승 ( Ho Seung Kim ),김태영 ( Tae Young Kim ),우세종 ( Se Jong Woo ),강건용 ( Kern Yong Kang ) 한국분무공학회 2014 한국분무공학회지 Vol.19 No.2

Pyrolysis oil (PO), also known as Bio crude oil (BCO), has the potential to displace significant amounts of fuels that are currently derived from petroleum sources. PO has been regarded as an alternative fuel for petroleum fuels to be used in diesel engine. However, the use of PO in a diesel engine requires modifications due to low energy density, high water contents, low acidity, and high viscosity of the PO. One of the easiest way to adopt PO to diesel engine without modifications is emulsification of PO with the fuels that has higher cetane number. However, PO that has high amount of polar chemicals is immiscible with non polar hydrocarbons of diesel. Thus, to stabilize a homogeneous phase of diesel-PO blends, a proper surfactant should be used. In this study, a DI diesel engine operated with diesel and diesel-PO emulsions was experimentally investigated. Performance and gaseous & particle emission characteristics of a diesel engine fuelled by diesel-PO emulsions were examined. Results showed that stable engine operation was possible with the emulsions and engine output power was comparable to diesel operation.

Increase of diesel car raises health risk in spite of recent development in engine technology

Leem, Jong Han,Jang, Young-Kee The Korean Society of Environmental Toxicology 2014 환경독성보건학회지 Vol.29 No.-

Diesel exhaust particles (DEP) contain elemental carbon, organic compounds including Polyaromatic hydrocarbons (PAHs), metals, and other trace compounds. Diesel exhaust is complex mixture of thousands of chemicals. Over forty air contaminants are recognized as toxicants, such as carcinogens. Most diesel exhaust particles have aerodynamic diameters falling within a range of 0.1 to $0.25{\mu}m$. DEP was classified as a definite human carcinogen (group 1) by the International Agency for Research on Cancer at 2012 based on recently sufficient epidemiological evidence for lung cancer. Significant decreases in DEP and other diesel exhaust constituents will not be evident immediately, and outworn diesel car having longer mileage still threatens health of people in spite of recent remarkable development in diesel engine technology. Policy change in South Korea, such as introduction of diesel taxi, may raise health risk of air pollution in metropolitan area with these limitations of diesel engine. To protect people against DEP in South Korea, progressive strategies are needed, including disallowance of diesel taxi, more strict regulation of diesel engine emission, obligatory diesel particulate filter attachment in outworn diesel car, and close monitoring about health effects of DEP.