• 한국가스학회지
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• 제27권2호
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• pp.57-64
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• 2023

가스계량기의 검침방식이 발전하면서 원격검침이 가능한 스마트 가스 계량기(누출점검용 계량기 및 다기능 안전 계량기)가 사용되고 있다. 이러한 계량기는 부가기능으로 수집하는 유량 및 압력 데이터를 활용하여 누출 판단을 하는 기능이 있다. 유량 데이터를 이용한 누출판단 기능은 실제 현장에서 유효한 사례가 있지만 압력 데이터 기반 누출 판단 기준은 누출로 인한 압력 값 변화뿐만 아니라 여러 요인(정압기 압력 크기, 인접 계량기 연계, 인접 주택 사용량, 계량기 위치 등)으로 압력 크기 변화(레벨)가 있는 문제점이 있다. 본 논문에서는 스마트 가스계량기에서 수집되는 압력데이터를 활용하여 누출여부를 판단 할 수 있는 기법으로 압력 데이터 전처리 방법과 누출 여부 관련 압력 값 범위 기준, 누출판단 기법 및 적용 사례 검증을 통해 개발하였다.

• 한국연소학회지
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• 제22권4호
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• pp.35-42
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• 2017

This case covers the issues related to the operation problem, cause analysis and improvement cases of the FGD that employed the non-leakage type GGH in coal-fired power plant for the first time in Korea. In the Cooler, there was a main problem that the tube is damaged by the ash cutting due to the high velocity of flue gas in the duct and by the weak wear resistance of material. In the Reheater, there was a main problem that the tube was corroded due to chlorine and sulfur in the circumstance of the low temperature. In order to solve those problems, we have improved the Reheater tube and tube fins by coating enamel to reduce corrosion rate.

• 한국산학기술학회논문지
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• 제6권5호
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• pp.373-377
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• 2005

본 논문에서는 반도체 제조장비의 챔버 내부 가스누출을 방지하기위한 보완모듈을 제시하였다. MFC(mass flow controller) 다음단의 최종밸브와 챔버 사이의 가스관에 압력센서를 부착시켜, 압력센서의 신호와 최종밸브의 동작신호를 디지털 회로를 이용하여 실시간으로 감지하고 가스누출을 방지하도록 하였다. LED 모듈을 이용하여 공정중에 발생하는 2차 소성물로 인한 가스의 흐름과 관련된 시스템 고장을 표시한다. 본 연구에서 개발한 모듈을 이용하면 챔버 내에서의 가스누출로 인한 장비의 손상과 안전사고 등을 예방하는 효과가 있다.

• 한국멀티미디어학회논문지
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• 제25권2호
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• pp.189-196
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• 2022

We have developed an embedded based environment sensing module with high-resolution temperature, humidity and gas sensors to detect gas leakage under the condition of LNG injection. The developed sensing module have linearity with gas concentration. We have confirmed the developed sensing module could detect LNG gas concentration of 5 cmol/mol and 15 cmol/mol, which are gas concentration at risk of explosion. The response time of the developed module was fast within 8 seconds. Therefore it can be used to detect LNG gas leakage.

• 한국전산유체공학회지
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• 제20권4호
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• pp.102-108
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• 2015

Recently, There are many studies in progress in order to improve the efficiency of the gas turbine. Leakage in losses of the gas turbine account for the largest proportion. Seal is a sealing device to reduce the flow from leaking by the pressure difference inside the turbine. Compressor has another value according to the shape and pressure conditions in each stage. Thus, it is necessary to seal design for boundary conditions in order to minimize leakage. At the actual operating conditions of the compressor, numerical analysis of honeycomb labyrinth seal was performed in accordance with pressure, temperature, rotor speed for CFD. As a result, when the temperature increases, the leakage is decreased. Also, when the pressure increases linearly with increased leakage, and there was no effect of the rotation speed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.925-928
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• 1999

A multi-channel gas leakage monitoring system was designed and fabricated by using CPLD(complex Programmable Logic .Device) for monitoring and controlling the leakage of natural gas from supplying-pipes under the ground. Fabricated SnO$_2$thick film gas sensor elements were attached on safeguard steel plate of natural gas supplying pipes, and the local monitoring system in this study received the signal from the gas sensors. The monitoring system was implemented by using CPLD chip to reduce the development time and implement simple one chip system. The time division multi-channel system received the input signal from individual gas sensor at one of divided times by multiplexor and signal processed sequentially. The system reduced the size of peripheral circuit resulted in implementation of creditable simple system.

• Journal of Mechanical Science and Technology
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• 제15권9호
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• pp.1217-1225
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• 2001

The governing equations are derived for the analysis of a stepped labyrinth gas seal generally used in high performance compressors, gas turbines, and steam turbines. The bulk-flow is assumed for a single cavity control volume set up in a stepped labyrinth cavity and the flow is assumed to be completely turbulent in the circumferential direction. The Moodys wall-friction-factor model is used for the calculation of wall shear stresses in the single cavity control volume. For the reaction force developed by the stepped labyrinth gas seal, linearized zeroth-order and first-order perturbation equations are developed for small motion about a centered position. Integration of the resultant first-order pressure distribution along and around the seal defines the rotordynamic coefficients of the stepped labyrinth gas seal. The resulting leakage and rotordynamic characteristics of the stepped labyrinth gas seal are presented and compared with Scharrers theoretical analysis using Blasius wall-friction-factor model. The present analysis shows a good qualitative agreement of leakage characteristics with Scharrers analysis, but underpredicts by about 20%. For the rotordynamic coefficients, the present analysis generally yields smaller predictied values compared with Scharrers analysis.

• International Journal of Computer Science & Network Security
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• 제21권11호
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• pp.59-66
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• 2021

Many incidents of Carbon Monoxide (CO) poisoning have occurred because of people being unaware of its presence. There are currently available systems on the market, but they are limited to measuring CO in a certain area and lack vital functions. Additionally, little to no evidence-based information on their quality was available. Thus, a mobile application for detecting CO gas leakage in a vehicle and critical features to assist victims was developed. A usability and functionality test were conducted to determine the product's quality utilizing nine usability and six functionality task scenarios (n=5). Then, a System Usability Scale test was performed to obtain system satisfaction, usability, and learnability (n=50). The usability and functionality test shows that all the tasks given for both tests were 100% successful. The overall score obtained for SUS was 71.4, which indicates good acceptance and usability. Around 20% of respondents claimed that they would need the support of a technical person to be able to use the application and that they needed to learn a lot of things before they could use the application, which indicates the overall high learnability of the application. The result provides empirical evidence that the CO gas leakage detection mobile application is successful and receives good usability, functionality, acceptability, learnability, and satisfaction assessments. DetGas could benefit automobile owners and other stakeholders by mitigating the risk and harm associated with gas leaking that exceeds the safe limit.

• 비파괴검사학회지
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• 제30권6호
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• pp.521-526
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• 2010

Gas transmission pipelines are often inspected and monitored using the magnetic flux leakage method. An inspection vehicle known as a "pig" is launched into the pipeline and conveyed along the pipe by the pressure of natural gas. The pig contains a magnetizer, an array of sensors and a microprocessor-based data acquisition system for logging data. This paper describes magnetic flux leakage (MFL) signal processing used for detecting mechanical damages during an in-line inspection. The overall approach employs noise removal and clustering technique. The proposed method is computationally efficient and can easily be implemented. Results are presented and verified by field tests from an application of the signal processing.

• 한국안전학회지
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• 제24권2호
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• pp.37-41
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• 2009

PVC hose for gas is used widely in many of places which is used for connector between combustor and gas cock. In this study, it is collected by 5 regional area as Gyeonggi, Jeonnam, Gyeongbuk, Jeju and Gangwon and tested in leakage, hardness, anti-low temperature. As a result, the color on it is started to change rapidly when it is installed. Some of specimen are broken in bending test after keeping in $-25^{\circ}C$, 24hours. It's hardness has a tendency to increase gradually. If hardness of hose is increased, PVC hose is separated easily from cock or combustor so that LP gas or city gas can be escaped. For prevention of gas leakage accidents of PVC hose, the available period of it should be presented.