• Transactions of the Korean Society of Automotive Engineers
• /
• v.7 no.8
• /
• pp.123-131
• /
• 1999

Natural gas is one of the most promising alternative fuels for automotive vehicles. However, natural gas varies in compositional between the originating fields and may be further modified due to processing and additional mixing. These variations are known to affect engine performance and emissions through changes in fuel metering and combustion characteristics. In the present study, the effect of gas compositions on vehicle performance such as fuel economy, driveability and exhaust emissions was examined. Analysis are made of using 3 types of NGVs which were made by automakers and 6 different fuels which are selected in consideration of the variation in fuel composition on the worldwide market. The results may be utilized to develop natural gas natural gas engine in automaekrs and/or to establish the fuel standard in the refueling stations.

• Journal of the Korean Institute of Gas
• /
• v.21 no.6
• /
• pp.70-80
• /
• 2017

According with annual report by the OECD (Organization for Economic Co-operation and Development), South Korea is at the top of the list of countries with bad air pollution (fine dust particles) and the South Korean government announced the cause to be due to the particle emissions of large and old diesel vehicles. To solve this issue, the government (jointly with related ministries), promoted the "Special Measures for Comprehensive Fine Dust Management Program" as a way to improve environmental pollution by reducing the overall output of fine dust particles emitted by public vehicles. The measure implemented a gas subsidy system to convert eco-friendly vehicles of city and chartered buses throughout the country. In this study, we take a look at the economical evaluation, comparison and analysis of the conversion of diesel vehicles to natural gas (CNG) vehicles. This report represent the basis for the need to expand the funds of the subsidy program and reviews the feasibility of the policy by taking into consideration the social and economical benefits and the effect in the environment when converting diesel fuel to natural gas vehicles through the type-specific fuel conversion scenarios.

• Journal of the Korean Institute of Gas
• /
• v.16 no.4
• /
• pp.1-7
• /
• 2012

Systematic safety research by Korea Government has been made to enhance the safety of CNG (compressed natural gas) vehicles since the burst of compressed cylinder of an urban bus in August 9, 2010. This article summarizes some major activities to ensure the safety of CNG vehicles, which covers review of regulation, safety management system including standard of inspection and certification, and training program of inspectors and car mechanics. Specifically, the followings were reviewed; type of CNG cylinder, location of CNG cylinder, material and type of fuel line and vent line, modification of pipeline connection, installation of gas detector, installation of emergency shutdown valve, installation of protecting cover for cylinder, obligations for CNG vehicle filling station. improving periodical inspection, routine test on gas vehicles, training program for engaged in gas vehicles, and designation of safety manager for CNG bus company. This paper suggests how to improve safety of CNG vehicles as a result of review of above mentioned check items.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.22 no.2
• /
• pp.205-212
• /
• 1998

Experiments were conducted to investigate the temperature profile and the emissions conversion efficiency of catalytic converters for natural gas vehicles. Two types of the catalyst structure and several transient engine operating conditions were used. The dual-bed catalyst effectively reduced the emissions in a transient period due to the low heat capacity of the front bed. The lanthanoid additives were effective in improving catalyst durability. When the natural gas fueled engine were operated outside of a very narrow window of excess air ratio (from 0.993 to 1.004), the HC and NOx conversion efficiency dropped off. The drop-off were especially fast on the lean side of the window.

• Journal of the korean Society of Automotive Engineers
• /
• v.23 no.3
• /
• pp.36-37
• /
• 2001

• Journal of Advanced Marine Engineering and Technology
• /
• v.34 no.5
• /
• pp.632-637
• /
• 2010

Natural gas, a fossil fuel contained mostly of methane, is one of the cleanest alternative fuels. It can be used in the form of compressed gas(CNG) or liquefied natural gas(LNG) to cars and trucks. And, dedicated natural gas vehicles are designed to run on natural gas only, while Bi-fuel vehicles can also run on gasoline or CNG, especially, bi-fuel can be defined as the simultaneous combustion of two fuels. In this study, converted gasoline marine system to CNG Bi-fuel system which is made up of injector, regulator, tank and ECU is converted. And estimated the fuel system and engine power compared the result with gasoline engine is estimated. As a result, CNG engine shows low exhaust emissions but maxium power is 7% reduced compared to gasoline engine.

• Journal of the Korean Institute of Gas
• /
• v.21 no.6
• /
• pp.1-7
• /
• 2017

This study is aimed to investigate the US code and European code on the evaluation of fuel economy of natural gas vehicles and deduce the formula suitable for domestic natural gas fuel. The fuel consumption formula have been derived by carbon balance relation between fuel composition and exhaust emission. The US code does not limit the composition of the test gas, but European code should be used the reference gases such as G20 and G23. In the case of NGV using domestic city gas, it is confirmed that the fuel economy determined by European code is 12% worse than that of US code because of difference of test gas. Also, a method of determining the fuel properties from the calorific value is proposed to evaluate the fuel economy of natural gas vehicles.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.252-257
• /
• 2006

In this study, the impact of the efficiency change of various appliances using natural gas has been investigated. Heating devices, cooking devices, cooling units, cogeneration systems and vehicles are of major concern for the investigation. In addition, foreign examples of demand side management for the units using natural gas have been surveyed. The expectations for the efficiency enhancement of natural gas devices were analyzed.

• Journal of the Korean Institute of Gas
• /
• v.15 no.1
• /
• pp.9-14
• /
• 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 B
• /
• v.27 no.9
• /
• pp.1238-1247
• /
• 2003

Simplified thermodynamic analysis of high pressure 4-stage reciprocating compressors with 4 inter-coolers has been investigated to predict a behavior of a compressor system for NGV(natural gas vehicles). A computer program has been developed to predict and estimate the performance of high pressure 4-stage reciprocating compressor system. Thermodynamic properties of compressed natural gas(CNG) were calculated by ideal gas theory and compression cycle was assumed as reversible adiabatic compression and expansion processes, and isobaric intake and discharge processes. Comparison between results predicted by calculation model and measured by experimental tests is presented.