• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.355-355
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• 2012

액체 누설을 감지하는 센서를 개발하였다. 이 센서는 경보 장치를 포함하며 접착 테이프형태의 박막 센서이다. 센서는 총 4개의 층으로 구성되어 있다. 각 층의 명칭은 접착제층, 베이스 필름층, 기판 필름층, 보호 필름층이다. 감지선의 사용량을 최소화하여 기판 필름층 위에는 총 4개의 선이 있다. 전도선 3개와 저항선 1개이다. 4개의 선들은 기판 필름층에 전도성 은나노 잉크를 그라비어인쇄기를 이용하여 센싱 회로를 인쇄하였으며 이 기술의 이 센서의 가장 큰 특징이다. 누수 발생 시에 저항선과 전도선에 액체가 접촉되어 회로 상에 교차하는 내부저항의 전압 변화를 모니터링하여 누수를 감지하는 방식의 센서이다. 감지선에 전원을 양방향으로 번갈아 인가함으로써 수분의 저항 값 증가 및 양극화를 방지하였다. 그로 인해 기존의 센서에 비해 좀 더 안정적이고 정확한 감지를 할 수 있다. 설치 후 센서가 마모되거나 손상될 시 간단하게 재설치 할 수 있다는 장점도 있다. 액체 누설 후에도 별도의 건조시간이 필요하지 않다. 표면에 남아있는 액체를 제거하여 즉시 재사용하는 것이 가능하다. 액체누설 감지 시스템은 액체누설 감지 필름 센서를 포함하며, 표시부와 경고음 발생부 등 전체를 제어한다. 표시부의 누설 위치 표시 단위는 미터(m)이며 최소 0.1 m 단위까지 표시한다. 이 액체누설 감지 시스템을 이용하여 누설 위치 감지 실험 및 액체별 누설 위치 감지 실험을 진행하였다.

• Journal of the Korean Vacuum Society
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• v.20 no.2
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• pp.146-154
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• 2011

The adhesive-tape of a liquid leak film sensor including the alarm system is developed. The sensing film is composed of three layers such as base film layer, conductive line layer, and protection film layer. The thickness of film is 300~500 um, the width is 3.55 cm, and the unit length is 200 m. On the conductive line layer, three conducting lines and one resistive line are formulated by the electronic printing method with a conducting ink of silver-nano size. When a liquid leaks for the electricity to be conducted between the conductive line and the resistive line, the position of leakage is monitored by measuring the voltage varied according to the change of resistance between two lines. The error range of sensing position of 200 m film sensor is ${\pm}1m$.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.12
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• pp.1108-1115
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• 2015

In this study, correlation equations were arranged about mass flow rates of oxygen and volume flow rates of helium using a mouthpiece method. The mouthpiece method can reduce examination cost by using similar empirical formula. Instead of liquid oxygen, in the mouthpiece method, gas helium can be measured in order to determine the leakage amount of liquid oxygen conveniently. Experiment was conducted and compared to understand leakage amount relation between the helium and the oxygen for prototype item under a room and a cryogenic temperature conditions. The leakage volume flow rate [$A.m{\ell}/s$] of the helium was 174 times higher than mass flow rate [g/s] of the oxygen leakage at liquid state. The derived correlation equations were verified using data from the National Institute of Standards and Technology (NIST).

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.85-91
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• 2001

This paper presents safety analysis of LNG leakage in a prestressed concrete outer tank, which is strongly related on the leak checking effects of the PC structure with and without a residual compression zone based on the BS 7777 codes. The full containment type outer tank which is constructed by a prestressed concrete may be destroyed by leaked cryogenic fluids. The FE calculated results show that the total leak checking time of the PC structure with $10\%$ residual compression zone is about 9 days for $-162^{\circ}C$ liquids. But, three primary pumps in an inner tank may operate to send cryogenic fluids for 6 days, which are stored in an inner tank of $140,000m^3$ capacity This means that the prestressed concrete outer tank may be safe for $-162^{\circ}C$ cryogenic fluids leaked from the demolished inner tank.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.109-110
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• 2005

하나로에서 발생하는 방사성폐기물은 물리적 특성에 따라 고체, 액체 및 기체 방사성폐기물로 분류된다. 고체 방사성폐기물은 방문객 및 종사자들의 원자로실에 출입하여 업무를 수행하는 과정에서 발생하며, 액체 방사성폐기물은 계통의 누설, 보수작업, 실험장비 설치 등의 원자로 운영과정에서 주로 발생한다. 본 논문에서는 2005년도 하나로 시설의 방사선 관리 구역인 원자로실에서 발생된 고체, 액체 방사성폐기물의 발생량과 이들의 저감화를 위하여 취한 조치를 기술하였다.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.4
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• pp.27-32
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• 2005

Liquid valve is divided into cylinder and liquid part or composed of a single body structure. It becomes a connected structure to cylinder head after inserting stainless(STS) shaft to Teflon packing. In injecting and intercepting fluid, working efficiency becomes low because of the top and bottom round trip operation the friction between Teflon packing and STS shaft fluid leakage, decline of working environment, and each part replacement. And so target value is unattainable in productivity liquid valve design, quality, and structure change are studied. In this paper, designed to solve the existing problems basically, to prevent friction of Piston by developing diaphragm linked with piston, to satisfy long life, and to provide the prevention of leakage. The objective of the study is also to prevent remains fluid at nozzle tip after dispensing fluid, and bell close with the suction function in piston retreating.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.6
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• pp.105-112
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• 2013

Turbopump is typically an assembly of rotors and casings, and there are a number of joints between them. Every joint should be leak-proof, so there is always a seal to accomplish the goal. Among various seals, metal seals are advantageous in that they are robust at high pressure, and at wide range of temperature. In this study, flange joints using conical seal made of stainless steel, solid flat metal seal made of copper and metal C seal made of Inconel 718 were structurally designed and analyzed, considering both initial tightening and operating conditions.

• Bulletin of the Korean Space Science Society
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• 2006.10a
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• pp.165-165
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• 2006

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.248-249
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• 2004

하나로는 1995년 2월에 첫 임계(criticality)에 도달한 이후로 핵연료의 조사시험, 동위원소 생산, 중성자 빔을 이용한 연구, 중성자 방사화 분석 등에 활용되고 있다. 하나로에서 발생하는 폐기물은 성상에 따라 기체, 액체, 고체 폐기물로 분류되며, 모두 극저준위 폐기물이다. 고체 폐기물은 방문자 및 종사자들이 원자로실에 출입하여 업무 수행 과정에서 발생하며, 액체 폐기물은 계통의 누설, 보수 작업, 실험 장비 등의 세척으로 발생한다.(중략)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.117-122
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• 2012

A blisk with rotor shroud is usually adopted in LRE turbine to maximize its performance. However it experiences severe thermal load and resulting damage during engine stating and stop. Shroud splitting is devised to relieve thermal stress on the turbine rotor. Structural analysis confirmed the reduction of plastic strain at the blade hub and tip. However, split gap at the rotor shroud entails additional tip leakage and results performance degradation. In order to assess the effect of shroud split on the turbine performance, tests have been performed for various settings of shroud split. For the maximum number of shroud splitting, measured efficiency reduction ratio was 2.65% to the value of original shape rotor.