• Journal of Advanced Marine Engineering and Technology
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• v.35 no.4
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• pp.379-387
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• 2011

Research and development of LP EGR system for the performance improvement and emission reduction on diesel engine is proceeding at a good pace. LP EGR system seems to be helpful method to further reduce$NO_x$ emissions while maintaining PM emissions at a low level because the boost pressure is unchanged while varying EGR rate. This study is experimentally conducted on a 2.0L common rail DI engine at the medium load condition (2000 rpm, BMEP 1.0 MPa, boost pressure 181.3 kPa) that difficult to use large amount of EGR gas because of deteriorations of performance and fuel consumption. And we investigated the characteristics of performance and fuel consumption while varying EGR systems. The overall results using LP EGR system equipped with ETC identified benefits on reduction of PM and improvement of fuel consumption and thermal efficiency while keep the $NO_x$ level compared to HP EGR and LP EGR with back pressure valve.

• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.54-59
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• 2006

A safety device with shut-off function was developed for preventing intentional accidents that might happen by separating of cutting hoses connected to pressure regulators used in residential LP gas facility. For the verification of function and field adaptability, the safety device with shut-off function was tested in the state of joining the device to the regulator and a field test was carried out at home. This study shows that, at the inlet pressure of 0.07-1.56 MPa, the device shuts off the gas within the 5m length of hose regardless of the installation condition of the regulator. The shut-off flow rate increases in the order of perpendicular upward, horizontal and perpendicular downward. From the results of the field tests carried out at home for 5 months, there appears no problem using a gas range or a boiler. If the developed shut-off device is commercialized and distributed in the market the intentional accidents occurred by cutting or separating hoses can be prevented remarkably.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.998-1000
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• 2003

We have investigated thin film morphology of pentacene thin films by the process of low-pressure gas assisted organic vapor deposition (LP-GAOVD). Source temperature, inert gas flow rate, substrate temperature and deposition pressure during film deposition is used to vary the growth rate, thin film morphology and the crystalline grain size of pentacene thin films. The electrical properties of pentacene thin films for applications in organic thin film transistor and electrophoretic displays will be discussed.

• 한국가스학회:학술대회논문집
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• 2006.11a
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• pp.101-108
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• 2006

• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.48-53
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• 2006

In case of fire and explosion which resulted from LP gas release of LPG vessel retail store, the populated area such as apartment complex is supposed to be damaged either partially or totally. To estimate the damage of LP gas explosion, we conducted quantitative risk analysis procedure as has been recommended by AIChE/CCPS. For incident scenario selection, event tree analysis was proposed. TNT equivalent method, SAFER Trace v.8.0 and probit model were also used for consequence analysis. The various methods and analyses which were performed in this study are presented with the effect zones in the layout.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.150-159
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• 2014

Since the release of mid-term domestic GHG goals until 2020, in 2009, some various GHG reduction policies have been proposed. There are two types of modeling approaches for identifying options required to meet greenhouse gas (GHG) abatement targets and assessing their economic impacts: top-down and bottom-up models. Examples of the bottom-up optimization models include MARKAL, MESSAGE, LEAP, and AIM, all of which are developed based on linear programming (LP) with a few differences in user interface and database utilization. In this paper, we suggest a simplified LP formulation and how can build it through step-by-step procedures.

• Journal of the Korean Institute of Gas
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• v.13 no.5
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• pp.1-6
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• 2009

This paper presents the fuel consumption effects of LPG vehicle depending on the atmospheric temperature, LP gas leakage of vaporizer, viscosity of engine oil and engine load conditions. The fuel consumption test results show that when the temperature of engine temperature rises, the fuel consumption efficiency increases in general. The fuel consumption efficiency for an atmosphere temperature of $24.2^{\circ}C$ is 13.6% high compared to that of $1^{\circ}C$. No leak vaporizer on fuel consumption efficiency is 5.3% high compared to that of the LP gas leak vaporizer. The fuel economy of new engine oils is just 1.1% high compared to that of used oils with a LPG vehicle mileage of 9,500km. This is not an influential factor compared with an atmospheric temperature and a LP gas leakage. The more important factors on the fuel consumption efficiency are driving conditions such as a rapid braking, abrupt start and fast acceleration. The test results indicate that the normal start is 32.3% high compared to that of an abrupt start and the fast acceleration is 10.8% high compared with that of an abrupt start. And the fuel consumption efficiency for a rapid braking is 18.3% higher than that of an abrupt start. These indicate that the driving condition is very important to reduce the fuel consumption rate.

• Journal of the Korean Institute of Gas
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• v.11 no.1 s.34
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• pp.23-28
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• 2007

This paper presents an experimental investigation on the sealing defects and cracks of O-rings and a valve packing of a gas valve for a LPG cylinder. O-ring in which stops a gas leakage of a liquefied petroleum gas is very important for a LPG valve safety. Valve packing is to open and close a gas flow port for supplying and charging a LPG fuel. The sealing performance of two sealing units ism related to the leak safety and long lift of a gas valve. The investigated results show that most of O-rings was failed due to a circumferential crack in which is caused by partial press bonding failure near the partition zone and an excess compression rate. Some of the O-ring failure was originated by an extrusion of an excessive leak pressure of a LP gas. Thus, this paper strongly recommends a tight quality control and a safety guarantee system of O-rings and valve packing to guarantee a leak safety and to extend a service lift of a gas valve. At the end, a warranty policy of the sealing units should be adopted for increasing a product quality and safety of a gas valve.

• Journal of the Korean Institute of Gas
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• v.12 no.3
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• pp.56-63
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• 2008

We have garnered 3,593 data of gas [Natural Gas (NG) and Liquefied Petroleum Gas (LPG)] accidents reported for 16 years from 1991, and then analyzed the accidents according to their types and causes based on the classified database. According to the results the gas leak has been the most common accident followed by the explosion and then fire accidents. The most frequent accident-occurring locations for fire, explosion and leak are recognized around the valve, hose and pipeline, respectively. In addition, we have applied the Poisson analysis to predict the most-likely probabilities of fire, explosion and release in the upcoming 5 years. From this research we have assured the successive database updating will highly improve the anticipating-probability accuracy and thus it will play a key role as a significant safety-securing guideline against the gas disasters.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.80-84
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• 2015

In this paper, the valves for a LPG gas cylinder have been investigated on the body height and weight by comparing design data between typical automatic shut-off vertical and newly developed horizontal valves. The height of an automatic shut-off horizontal valve is radically reduced by 41~42% compared with that of a typical automatic shut-off vertical valve. And, the body weight of a horizontal valve is also reduced by 29~40% compared with that of a vertical shut-off valve. This result is just achieved by a structural design modification from typical vertical valve to horizontal arrangement of various valve components.