• Journal of ILASS-Korea
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• v.22 no.4
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• pp.185-189
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• 2017

In Korea, sales of passenger cars using diesel and LPG fuels were continuously increased in recent years. From now on 2030, the registrated vehicles will close in about twenty five million in Korea. From these reason, Investigation on the comparison of exhaust emission characteristics of passenger cars using LPG and Diesel fuel in variation of driving mode and ambient conditions were conducted in this study. Exhaust emission characteristics of test vehicles were measured and analyzed by using chassis dynamometer and emission analyzer. Also, test vehicles were selected on the diesel vehicle with 1.7L engine and LPG vehicle with 2.0L engine. In order to study on emission characteristics according to driving cycles, CVS-75, NEDC, US06, SC03, Cold-FTP and HWFET were applied and the test conditions were set up the cases of A/C on and hot start. From these results, it is revealed that the NOx emission of diesel vehicle was higher than that of LPG vehicle and the case of CO emission shows the opposite patterns. In the HC emission, the emission increasing patterns not showed but the NOx emission of diesel vehicle and CO emission of LPG vehicle were showed the variation patterns according to the various driving modes.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.4
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• pp.269-275
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• 2017

$NO_X$ reducing technique such as LNT, LNC, and selective catalytic reduction (SCR) have been developed and applied, especially on heavy-duty vehicles. However, it is expected that $NO_X$ reduction techniques will also be applied to diesel passenger vehicles. The urea-SCR system is receiving attention as the most effective $NO_X$ reduction technology without a fuel penalty. Thus, many advanced countries are developing this technology. The urea-SCR system sprays an aqueous urea solution that separates $NO_X$ into $N_2$ and $H_2O$, which are harmless and emitted into the atmosphere. The urea injected in front of the SCR catalyst should be changed to 100％ $NH_3$, which is required for $NO_X$ reduction in the SCR system to maximize the reduction efficiency. The purpose of this study was to determine the basic data for the urea-SCR system to maximize the $NO_X$ reduction efficiency by understanding the $NO_X$ reduction characteristics in a real passenger vehicle to comply with the post EURO-6 emission regulation.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.92-99
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• 2011

To measure the traffic pollutants with high temporal and spatial resolution under real conditions, a mobile emission laboratory (MEL) was designed. The equipment of the mini-van provides gas phase measurements of CO, NOx, $CO_2$, THC (Total hydrocarbon) and number density & size distribution measurements of fine and ultra-fine particles by a fast mobility particle sizer (FMPS) and a condensation particle counter (CPC). The inlet sampling port above the bumper enables the chasing of different type of vehicles. This paper introduces the technical details of the MEL and presents data from the car chasing experiment of diesel bus equipped with aftertreatment system. The dilution ratio was calculated by the ratio of ambient NOx and tail-pipe NOx. Most particles from the diesel bus were counted under 300 nm and the peak concentration of the particles was located between 30 and 60 nm. The total PM number emission from diesel bus equipped with DPF was 10 orders of magnitude lower compared to those emitted from base diesel bus. And the total PM number emission from diesel bus equipped with SCR was comparable to the particle emission from base diesel bus.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.1
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• pp.71-76
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• 2002

Because the driving time is increased under the low speed by rapidly increasing of vehicles, this paper is presented a new ignition control system for improvement the fuel economy, which only some of cylinders are using under the idle status or low speed and preserving the engine rpm. is applicable to effective in fuel economy. An actual hardware was made to prove this new control system. The developed variable cylinder engine concentrated the heat neat the cylinders in idle status or low speed, so there was a problem in re-ignition. It was the reason of a lot of exhaust gas, high fuel consumption and instability of engine revolution. In this paper, in order to solve above problem to show the improvement fuel economy using the new ignition control system and valve opening period at idle status of low speed.

• Journal of the Korean Institute of Gas
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• v.15 no.1
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• pp.9-14
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• 2011

Heavy duty diesel engine has relatively small portion of whole vehicles due to long drive distance and large engine displacement, but largely influences atmosphere environment. City buses changed to CNG (Compressed Natural Gas) bus with Korea-Japan Worldcup. Heavy duty truck and intercity bus, however, were impossible to use CNG because those kinds of vehicles had long drive distance and CNG station was installed mainly at the around of the bus garage of city. Insulation container storing the natural gas as a liquid makes heavy duty truck and intercity bus possible to use the natural gas. Drive using diesel is possible where is hard to recharge the gas. With LNG (Liquefied Natural Gas), the dependence on oil is largely decreased, PM (Particulate Matter) and NOx which is chronic disadvantage of diesel is remarkably reduced and finally $CO_2$, the representative green house gas, is reduced over 10%.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.8
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• pp.1059-1067
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• 2013

Automotive fuel tank is generally divided into two parts: main frame and assembly parts. While the car is running, valves are used to prevent liquid carry over and to discharge evaporated gas from the fuel tank. However, current fuel tank designs focus on the gas ventilation or secured location. In this study, the location of the parts used to prevent liquid carry over within the fuel tank is evaluated during an optimal design process. To develop this design process, an approximate optimization is applied. Through the optimal design process, the optimal valve location in fuel tank is determined and the approximate optimization is validated by the Taguchi method. Finally, the optimized valve location is used to reduce the development cost and time and to contribute toward improved automobile quality owing to enhanced reliability.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.10-15
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• 2009

Emission regulations on greenhouse gas(GHG) in automobiles have been stringent because of global warming effect. Over 90% of total GHG emission are carbon dioxides and about 20% of this $CO_2$ emission are emitted from automobiles. In this study, 110 vehicles were tested on a chassis dynamometer and $CO_2$ emissions and fuel economy were measured in order to investigate the characteristics of $CO_2$ emission factor from passenger vehicles which are the most dominant vehicle type in Korea. The characteristics of emissions in accordance with displacements, gross vehicle weight, NIER and CVS-75 speed mode were discussed. It was found that vehicles having larger displacement, heavier gross vehicle weight, automatic transmission and specially at cold start emitted more $CO_2$ emissions. From these results, correlation between $CO_2$ emission and fuel economy was also obtained. This study may contribute to evaluate domestic greenhouse gas emissions and establish national policies on climate changes in future.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.37-44
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• 2012

Natural disasters such as hurricanes, floods frequently occurs in the world. The cause of the natural disasters that occurs due to global warming because of increasing of global greenhouse gas emissions. To prevent the global warming, lots of researchers are studying renewable energy area. In order to protect grobal warming, government is trying to reduce green gas emissions under "Low Carbon Green Growth Policy" and investing climiate-friendly industries such as renewable energy harvesting. Research team is developing a renewable energy system that harvests mechanical energy imparted to road from driving vehicles and generates it into renewable electricity. This paper presents the research results of size effect of the piezoelectric ceramic and connection of piezoelectric ceramics. Power characteristics of piezoelectric ceramic as function of experimental variables were measured and analyzed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.395-400
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• 2017

The paper discussed the air-to-fuel ratio control of automotive fuel-injection systems using the cerebellar model articulation controller(CMAC) neural network. Because of the internal combustion engines and fuel-injection's dynamics is extremely nonlinear, it leads to the discontinuous of the fuel-injection and the traditional method of control based on table look up has the question of control accuracy low. The advantages about CMAC neural network are distributed storage information, parallel processing information, self-organizing and self-educated function. The unique structure of CMAC neural network and the processing method lets it have extensive application. In addition, by analyzing the output characteristics of oxygen sensor, calculating the rate of fuel-injection to maintain the air-to-fuel ratio. The CMAC may easily compensate for time delay. Experimental results proved that the way is more good than traditional for petrol control and the CMAC fuel-injection controller can keep ideal mixing ratio (A/F) for engine at any working conditions. The performance of power and economy is evidently improved.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.98.2-98.2
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• 2011

지구 온난화의 원인이 되는 이산화탄소를 저감하며 유해한 배기가스를 배출하지 않는 수소연료전지자동차(FCV)에 대한 관심이 높아지고 있다. 한국가스안전공사에서 현재 구축하고 있는 평가장비는 이러한 수소연료전지자동차용으로 사용되는 고압용기의 수압반복시험 및 밸브류로 구성된 고압수소저장시스템의 단품 및 시스템 평가를 통한 안전신뢰성 검증을 목적으로 하고 있다. 현재 수소연료전지자동차는 차량이나 부품의 시험 방법에 대한 통일된 기준/표준/시험법이 아직 완전하게 정비되어 있지 않고, 시장에서의 도입 제도, 기준 등이 만들어지고 있는 현실이다. 또한 연료로 수소를 사용하는 도입단계에 있기 때문에, 수소용기가 반복압력변동에 따라 어떤 거동을 나타내는지에 대한 실험관련 연구가 미진한 상태이다. 따라서 수소연료전지자동차용 고압수소저장시스템에 대한 내구성, 안전성 확보를 위하여 수소연료전지자동차에서 중요한 부품인 용기에 대한 반복피로시험이 필요하다. 특히 복합재 용기 분야에서 Type3용기에 대한 높은 안전성과 내구성이 보고되고 있지만 실질적으로 얼마나 다른 용기에 비해 높은 성능을 가지고 있는지 국내에서는 체계적으로 검증된바 없다. 따라서 구축된 수압반복 장비를 이용하여 Type3 용기에 대한 수압반복시험을 실시하였으며, 이를 통해 수소용기의 거동을 확인하고자 한다.