• 월간 기계설비
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• s.65
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• pp.80-85
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• 1995

아파트에서 기계실에 인접한 세대나 1층세대의 경우 소음으로 인한 민원이 자주 발생하고 있다. 이러한 기계실에서의 소음, 공동구에서의 소음, 지하층에서의 배관소음 등의 발생원인 및 그 대책에 대하여 알아 보기로 한다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.46-52
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• 2024

The structural safety of expansion joints for piping systems has been drawing attention owing to ruptures and leaks of water pipes caused by earthquakes and road subsidence at soft ground. In general, metal bellows are installed as expansion joints to prevent various damages in the piping system. In this study, the seismic performance of a valve chamber system was evaluated by performing earthquake shaking table tests. To validate the benefits to structural safety of metal bellows in connecting steel pipes to valve chambers, the seismic tests were conducted on expansion joints (bellows) and general pipping, and the results were compared for durability. Strain gauges were attached to measure the effects of the input motion. As a result of the shaking table test, it was confirmed that the strain of the valve chamber structure and inflow or outflow steel pipes were decreased in 1/100, 1/20 by applied to the expansion joints.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.228-233
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• 2004

The length of city gas pipeline is increasing with expansion of natural gas transmission rapidly. A lot of the expense was paid for repair and maintenance with increasing of pipeline length and the cost of repair and maintenance by the corrosion was the highest. It is necessary to evaluate integrity in case of thickness reduction by corrosion. There are a lot of assessment criteria for corrosion defect in foreign countries but they are not suitable for application in the country directly. In this work, we performed the burst test and the finite element analysis for city gas pipeline, KS D3507 and KS D3631 for city gas transmission, and developed the assessment method of corrosion defect, which is suitable for domestic condition.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.397-402
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• 2003

Fracture resistance curves for concerned materials are required in order to perform elastic-plastic fracture mechanical analyses. Fracture resistance curve is built with J-integral values and crack extension values. The objective of this paper is to apply the load ratio method to the measurement of the crack length for the real scale pipe specimen. For these, the fracture test using the real scale pipe specimen and finite element analyses were performed. A 4-point bending jig was manufactured for the pipe test and the direct current potential drop method and the load ratio method was used to measure the crack extension and the length for the real scale pipe test. Finite element analyses about the compliance of the pipe specimen were executed for applying the load ratio method according to the crack length.

• Fire Science and Engineering
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• v.33 no.4
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• pp.1-8
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• 2019

Reaction-to-fire performance of pipe insulation materials should be approved in accordance with KS standards prior to installing water-based suppression systems because several fire accidents are initiated from insulation materials around ceilings or concealed space. A small room test to evaluate the reaction-to-fire performance of the polyethylene foam and elastomeric pipe insulation materials was conducted according to ISO 20632. Different fire growth rate and heat release rate are observed depending on the materials and construction methods. In order to improve a fire safety, the reaction-to-fire performance of pipe insulation material needs to be subdivided with regard to the heat release rate and smoke generation. Furthermore, the characteristics of the applying space are also required to be considered. Subsidiary materials for installation process such as tape and adhesive are found to provide an adverse effect to maintain a fire safety.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.965-966
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• 2012

• 월간 기계설비
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• s.169
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• pp.29-46
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• 2004

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.3
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• pp.1-9
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• 2005

An acoustic analysis of a fuel-rich gas generator for the drive of a turbopump in a liquid rocket engine has been performed and the length of a duct has been determined by comparing the resonant frequency of unstable acoustic modes to simulate an flight model gas generator, A practical short-length simulating duct has been determined by considering 1 or 2 wavelength of the unstable modes. Length adjustment of duct to turbopump can be a method to suppress a combustion instability problem by decoupling of acoustic mode and combustion characteristics. This method has been set up and validated with acoustic analysis and hot firing tests.

• Journal of Korean Society of Steel Construction
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• v.23 no.5
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• pp.569-579
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• 2011

Heating pipes, which are among the main equipment in district heating systems, can be classified into supply and return pipes. Because when the district heating transmission pipe, which is charged with district heating in small to medium-size cities, is under thermal stress during temperature variances in heating water, it suffers from the fatigue phenomenon caused by the thermal stress, according to the number of its service years. District heatingpipes have shown various characteristics according to the operating condition of the service connections, and the irregular temperature variance has had a bad influence on fatigue heating pipes. Therefore, in this study, a field test on laid heating pipes was performed, and the data for each region were analyzed. Also, the fatigue safety of district heating pipes was evaluated via cycle-based evaluation and stress-based evaluation.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.7-10
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• 2012

최근 고층건물 화재의 대표적 사례인 부산 해운대 우신골드스위트 주상복합건물 화재 확대의 주요 원인으로 작용했던 석유화학제품 중 배관보온재를 감싸고 있는 보온필름의 화재특성에 대해 연구를 하였다. 본 화재결과 배관보온필름이 화재취약성을 가지고 있는 것으로 확인되었다. 하지만 명확한 법적규제가 없는 것과 시공비 절감을 위해 대부분의 공사업자들은 비난연제품으로 시공을 하고 있는 실정이다. 따라서 본 연구에서는 이러한 잘못된 시공으로 인한 위험성을 알리고자 하는데 목적이 있다. 연구방법은 국내에서 생산된 마감용 배관 보온필름 네 종류를 사용하여 화재특성을 분석하였다. 네 종류 중 두 종류는 난연성능이 있는 제품이고 나머지 두 종류는 난연성능이 없는 제품으로 선정하였다. 실험은 제품의 열방출률을 알기위해 콘칼로리미터를 사용하였고 또한 실제 피트 내에 배관보온필름 화재를 묘사하기 위해 45도연소시험기를 사용하여 연소실험을 하였다.