• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.9
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• pp.449-454
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• 2015

In this study, the effects of lock operations on the infiltration rates for the two window types sliding and lift sliding (LS) are investigated through experiment and simulation. The airtightness levels of the two window types-with locks both on and off-were measured according to the KS F 2292 Test method of airtightness that is used for windows and doors. The air-flow rates of both window types with the locks on for a pressure differential of 10 Pa are $1.98m^3/(m^2h)$ and $1.68m^3/(m^2h)$, respectively; with the locks off, the air-flow rates of the sliding and LS windows are $2.64m^3/(m^2h)$ and $5.83m^3/(m^2h)$, respectively, whereby the air-flow rates are 33% higher for sliding and 247% higher for LS. The air change per hour (ACH) was calculated using the ventilation-simulation software CONTAM. For the sliding window, the ACH changed from 0.45 to 0.57 when the lock was operated from on to off, representing an increase of 27%. For the LS window, the ACH changed from 0.29 to 0.81, showing an increase of 179%.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.11
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• pp.1-7
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• 2020

Recently, hydrogen has gained considerable attention as an eco-friendly fuel, which helps in reducing carbon dioxide content. Specifically, there is a growing interest in vehicles powered by a hydrogen fuel cell, which is spotlighted as an environmental-friendly alternative. A hydrogen transport system, fuel cell system, fuel supply system, power management system, and hydrogen storage system are key parts of a hydrogen fuel cell truck. In this study, a hydrogen storage system is built and analyzed. The expansion length of the storage vessel at maximum operating pressure (87.5 MPa) was calculated with ABAQUS, and then the optimized system was designed and built. The leak and bubble tests were performed on the built storage system. The leakage of the system was measured to be under 5 cc/hr. Hence, it can be used as a research test for the safety evaluation of leading systems of hydrogen fuel-powered commercial vehicles.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.2
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• pp.60-71
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• 2022

The reusable, low-cost launch vehicle development trend in the recent launch vehicle market is being subdivided into several ways, and the throttleable engine is one of them. Plus, several nations have selected methane as a next-generation propellant due to its cleanness. In this research, a throttleable pintle injector using gas methane and liquid oxygen as propellants was developed, followed by its spray and combustion characteristics analysis, including high pressure cold and hot tests. The designed throttleable pintle injector has a double sleeve structure, and its tightness and functionality are confirmed through repetitive atmospheric, high-pressure cold tests, and hot tests. Though some design errors were discovered and a low throttling level was unable to be achieved in the combustion test.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.10-17
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• 2019

According to South Korea's policy of supplying eco-friendly hydrogen vehicles, related industries are actively conducting research on the development of hydrogen cars and hydrogen charging station infrastructure. On the other hand, there is a lack of empirical research and assessment of the risk of non-metallic materials (such as liners, seals, gaskets) for classified materials that directly affect the durability and reliability of hydrogen vehicles and hydrogen charging stations. In this study, the risk factors for liners and seals of non-metallic parts used in high-pressure hydrogen installations were derived using FMEA, and the RPN values were calculated by converting the severity, frequency of occurrence and degree of detection into scores. The maximum value of the RPN 600, minimum value 63, average value 278.5 was calculated and periodic control of the liner and seal was identified as important. In addition, through hydrogen soakage and oxygen aging tests for non-metallic rubber products, physical test values that can be used as basic data were presented.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.47-47
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• 2010

게이트 밸브는 진공 시스템 구성에 있어서 빠질 수 없는 중요한 부품 중 하나로 공간을 구획하여 필요에 따라 자유롭게 진공 상태와 대기 개방 상태가 공존하도록 만들어 주며 진공펌프와 같은 주요 기기들의 탈착 및 교체를 용이하게 해 준다. 게이트 밸브는 열린 상태에서는 저항이 최소화되는 반면 닫힌 상태에서는 마치 마구리 플랜지로 막은 것처럼 완벽한 차단이 요구된다. 일반적으로 게이트 밸브 상용제품은 개스킷이 닿는 밸브 시트가 한쪽에만 마련되어 있으므로 디스크 기계구조가 충분한 압력을 발휘하지 못한다면 어느 쪽이 대기압인가에 따라 디스크를 미는 힘의 크기가 변하여 기밀특성이 달라질 수 있다. 따라서 게이트 밸브의 누설검사는 순방향과 역방향 모두에 대해 시행해야 한다. 양방향 누설검사를 위해 한쪽 밸브 공간을 배기하고 반대쪽 공간에 헬륨을 뿌리는 작업을 교대로 하려면 배기시간의 단축과 신속한 잔류 헬륨기체 제거가 필수적이다. 게이트 밸브 제조 공장에서 상품을 출하하기 위한 시험검사라는 것을 전제로 합리적인 시간 내에 정확한 누설검사를 일관성 있게 할 수 있는 적절한 누설검사 시스템을 설계하고 측정절차를 상용 게이트 밸브에 대해 적용해 보았다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.273-276
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• 2008

A Through Bulkhead Initiation Module(TBIM) has been designed which guarantees the seal property without using O-ring. The TBIM works as the shock wave generated by a donor charge transmits to the acceptor charge. The structural safety of TBIM housing has been calculated via modeling analysis, and the ignition performance has been proved by 10 cc closed bomb test. The reliability analysis has been made using Probit method on the base of performance test results. According to the reliability analysis the bulkhead thickness of TBIM which is the most important design parameter has been determined.

• Journal of the Korean Institute of Gas
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• v.4 no.4 s.12
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• pp.6-12
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• 2000

We have developed a new split tee which can be used to effectively branch into a main gas steel pipelines without losing any gas pressure or having to shut down a line. The split tee has been designed considering the locations of branch connection to the pipelines. Therefore, we could keep the depth of buried pipelines which used to be the problem of the conventional split tees. Test results of the developed split tee showed that the performance of the tightness, hydraulic strength, sealing, welding, bending, and compatibility were excellent. The application of the split tee can provide the advantage of eliminating cost and time, and easy field pipeline coatings.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.331-336
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• 2003

The advanced spent fuel conditioning process(ACP) was proposed to reduce considerably the overall volume and radioactivity for effective management of the PWR spent fuel in respects on safety and economy. The ACP is under research and development, and have scheduled to perform hot test for demonstration of the ACP after several years. For hot test, hot cell facility of ${\alpha}{\gamma}$ type possess conservative safety is required essentially. A existing hot cell of ${\beta}{\gamma}$ type will be refurbished to minimize construction expenditures of hot cell facility. In this study, the design requirements are established, and the process detail work flow was analysed for the optimum arrangement to ensure effective process operation in hot cell. And also, the basic and detail design of hot cell facility and process and safety analysis was peformed to secure conservative safety of hot cell facility and process.

• The Journal of Engineering Geology
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• v.12 no.1
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• pp.35-51
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• 2002

This study aims to establish the methodology for design of an optimum water curtain system of the unlined underground oil storage cavern satisfying the requirements of hydrodynamic performance in a volcanic terrain of the south coastal area. For the optimum water curtain system in the storage facility, the general characteristics of groundwater flow system in the site are quantitatively described, i.e. distribution of hydraulic gradients, groundwater inflow rate into the storage caverns, and hydrogeologic influence area of the cavern. In this study, numerical models such as MODFLOW, FracMan/MAFIC and CONNECTFLOW are used for calculating the hydrogeological stability parameters. The design of a horizontal water curtain system requires considering the distance between water curtain and storage cavern, spacing of the water curtain boreholes, and injection pressure. From the numerical simulations at different scales, the optimum water curtain systems satisfying the containment criteria are obtained. The inflow rates into storage caverns estimated by a continuum model ranged from about 120 m$^3$/day during the operation stage to 130~140m$^3$/day during the construction stage, whereas the inflow rates by a fracture network model are 80~175m$^3$/day. The excavation works in the site will generate the excessive decline of groundwater level in a main fracture zone adjacent to the cavern. Therefore, the vertical water curtain system is necessary for sustaining the safe groundwater level in the fracture zone.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.127.2-127.2
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• 2010

우리나라는 기후변화 대응을 준비하기위해 2008년도에 수립한'국가에너지기본계획(2008-2030)'에 따라 2030년까지 신재생에너지 비중을 2.4%에서 11%까지 달성을 목표로 정하고 신재생에너지 분야를 성장시키기 위해 국가기술개발 및 산업화 전략을 수립해 추진하고 있다. 이에 발맞추어 건물용 연료전지시스템의 경우, 2006년도부터 1kW급 가정용 연료전지시스템 모니터링 사업의 일환으로 3년간 210대가 도시가스사 및 지자체 등을 중심으로 설치되어 운전되어지고 있다. 특히, 2010년부터 시범보급사업이 추진되어 올해 200대를 시작으로 2011년에 300대, 2012년에 500대가 일반가정에 보급되어질 예정이다. 하지만 현재 6천만원인 연료전지시스템 가격을 실제 보급가능한 가격인 5백만원 이하로 저감시키는 것이 현 시점에서 가장 시급한 문제로 대두되어지고 있는 실정이다. 본 연구에서는 그린홈 보급확대를 위한 건물용 연료전지의 보조기기인 블로워의 가격저감을 위한 연구의 일환으로 블로워의 안전성능 평가방법을 개발하여 보조기기의 가격저감 및 안전성을 확보하고자 한다. 1kW급 건물용 연료전지시스템의 여러 블로워 중 도시가스용 연료승압 블로워, 선택산화 공기 블로워, 버너 공기 블로워 및 캐소드 공기 블로워의 안전성능 평가방법을 제시함으로서, 국내 블로워 제조사의 설계방향을 제시하고 연료전지시스템의 안전성을 확인하고자 한다. 특히, 내구성, 기밀, 가혹조건시험 및 소음, 진동, 습도, 온도와 같은 내주위환경시험 등의 평가결과를 제조사에 feedback하여 안전성능 개선에 이바지하고자 한다.