• 월간 기계설비
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• s.35
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• pp.84-96
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• 1993

본 연구는 '초고층 아파트 최적 설비시스템 개발'의 제2차년도 연구로서 아직까지 국내에서 확립되어 있지 않은 초고층 아파트 급수설비 시스템 및 수격방지 시스템의 모델정립과 연돌효과에 의한 열손실 추정 및 적정 설계 지침 설정에 관한 연구를 수행하였다. 이를 위하여 이론 해석 및 현장실험을 수행하였고, 결과분석을 통하여 최적화 설계방안도 아울러 도출하였다. 급수설비 분야에서는 각종 급수 시스템의 해석 및 비교를 통한 효율적인 시스템의 설계 및 선정방법을 제시 하였고, 실제 초고층 아파트에 대한 수격현상 해석 및 실험을 통하여 수격작용의 영향을 감소시킬 수 있는 설계방안을 검토하였다. 또 입주중인 초고층 아파트 현장에서의 실측을 통하여 건물의 높이에 따라 불균일한 틈새가 있는 일반적인 경우에 대한 모델을 정립하였고, 수치해석을 통한 수직통로 내의 실제 열유동 현상을 정량화하고 설계지침을 제시하였다. 결과로서 각종 급수시스템의 해석을 위한 프로그램을 개발하였고, 수격의 발생을 억제하기 위한 최적 밸브 폐쇄형태를 제시하였으며, 초고층 건물의 내외부에 형성되는 압력차와 유인풍량 및 열손실량 사이의 관계식을 얻었다.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.13 no.1
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• pp.69-74
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• 2017

In the fire protection system or fire fighting water supply system, the jockey pump is generally installed for the prevention of the pressure decrease of pipes, the frequent driving of the fire pump and protection the pipes from the water hammer. In this paper, the pressure-rise in fire fighting water distribution pipes in condition of pipe pressurization by the surge tank at the start-up and the sudden-stop of the fire pump without additional installation of jockey pump is considered by using simple formula calculations and the evaluation of water hammer occurrence in condition of pipe pressurization by the surge tank is included. As a result, the pressure-rise of pipes is less than the pipe design pressure at the condition of pump's start-up and sudden stop, and the possibility of water hammer occurrence is remarkably low due to pressurization of the pipes by the surge tank.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.164-174
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• 2007

Phenomena of hydraulic transient such as water hammer should be analyzed to design the pipeline systems effectively in dam. Surge tanks generally are used to reduce change in pressure caused by hydraulic transient from load changes on the turbines. In this study, the appropriate scale of surge tank with chamber is investigated for dam safety management. The variation of water level in the surge tank are computed using governing equation. Using the Thoma-Jaeger's stability condition, static and dynamic stability are investigate for the cases of flood water level, normal high water level, rated water level and low water level. Finally appropriate diameters of shaft and chamber are determined in the surge tank with chamber.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.3869-3875
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• 2012

In this study, mathematical modeling and experimental analysis were executed in order to evaluate the valve dynamic characteristics when the hydraulic pressure applied. High pressure on the master cylinder effects on the valve dynamic characteristics have been analyzed. The pulsation pressure generated in hydraulic systems causes noise, vibration and odd effect to the system. To reduce the pulsation pressure, high frequency PWM control of 20KHz was attempted. Also, an analytic method is proposed for the resultant forces of electromagnetism and hydraulic pressure generated in the real vehicle electro stability program. Consequently, results of solenoid valve dynamic characteristics analysis derived in the study can be confirmed criteria for the optimal control of electronic stability program system.

• The KSFM Journal of Fluid Machinery
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• v.8 no.5 s.32
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• pp.22-28
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• 2005

As the water supply facilities are recently getting larger, the domestic waterworks become multi-regional water supply system. Large water supply facilities generally consist of the intake pumping station, water treatment plant and water supply/distribution facilities. Although the pumping stations and the pipeline systems are used to pump up water, it often happens pipeline damage and flooding accident by the water hammer. In this paper, the intake pumping station is guaranteed by both the computer simulation and the field test analysis. This study is contributed to the safe operation program for the pumping station in which results of the adjustment on the safety plan of the pumping station, the air valve and the valve closing time.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.199-207
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• 2004

Water supply facilities are recently getting larger according as domestic waterworks become multi regional water supply system. Large water supply facilities generally consist of the intake pumping station, water treatment station and water supply & distribution facilities. Although pumping stations and pipeline systems are used to pump up water, it often happens pipeline damage and flooding accident by the water hammer. As a result of this study, a pumping station is guaranteed by the computer simulation and field test analysis. Therefore these are contributed safety operation in pumping station through adjustment of the pumping station safety plan, air valve and valve closing time.

• The KSFM Journal of Fluid Machinery
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• v.12 no.5
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• pp.19-24
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• 2009

This paper is performed to find out the stability of water-hammer in pipe line and pump station that is happened when additional water needs demanded. At first, the water supply construction project is planned to supply $6,000\;m^3/day$ through 17.9 km pipe line. But additional demand ($1,200\;m^3/day$) happened from Cheong-ra water reservoir. In this situation, air-chamber($4\;m^3$) and vacuum breaker valve(${\varphi}100\;mm$) are needed to prevent water-hammer. When the additional water is supplied, the existing facilities (air-chamber, vacuum breaker valve) are sufficient to alleviate shock not changing capacity alteration, judging from the airspace change and rise. Therefore, there is no problem for water-hammer by installing air-chamber($4\;m^3$) and vacuum breaker valve(${\varphi}100\;mm$) at the top of Yeo-ju hill.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.12
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• pp.1047-1055
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• 2002

The present study is to investigate the pressure wave characteristics and the absorption of the maximum and minimum pressure generated by instantaneous valve closure and opening at the end of the straightening copper Piping system with and without an air chamber. Also, life of air chamber is investigated. Experiments were conducted under the following conditions: initial pressure of 1～5 bar, flow velocity of 0.5～3.0 m/s, water temperature of$20^{\circ}C$ and air chamber volume of 45.1～449.5$cm^3$ The results of the study can be used in sizing air chamber and selecting the water hammer absorbtion apparatus.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.31 no.1
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• pp.9-14
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• 2002

산업의 발전에 따른 도시화의 영향으로 대도시에서는 가용공간을 확보하기 위하여 건물의 고층화와 지하공간의 개발이 활발하게 이루어지고 있다. 최근 증가추세에 있는 초고층주상복합건물, 초고층아파트는 건물의 높이가 증가함으로 인하여 건축공사비의 증가는 물론 설비적인 측면에서는 저층부의 수압이 상승 하여 높은 수압과 수격작용(water hammer)에 대한 배관 및 기기의 내압강도와 안전대책이 요구된다. 또한 건물의 초고층화로 인하여 열원에서 공조기까지, 공조기에서 실내기기까지의 수직거리 (vertical distance)가 길어지게 되어 연장된 공조덕트 및 배관 의 길이로 인해 반송동력비의 상승에도 큰 영향을 미치게된다. 이러한 문제점을 해결하기 위하여 기기 및 재료의 선정시 내압을 고려하거나 기기의 적정배치와 조닝(zoning)을 통해 상기의 문제점을 해결하는 방법을 적극 채용하고 있다. 하지만 보다 근본적인 문제해결 방법으로 건물의 층고저감에 의한 건축공사비 및 연 간운전비의 절감을 통한 건물에서의 소비에너지량 감소로 부존자원이 부족한 우리나라의 에너지수급정책에 기여하여야 할 것이다. 본 고에서는 건축물의 층고저감 효과를 얻을 수 있는 공조시스템에 대해 전반적으로 기술하고자 한다.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.61-64
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• 2006

Recently the development of small hydropower generation with using water pipes is revitalized by the water works facilities. However, when the tubine generator is in case of emergency stop by the internal and external accidents, it causes water hammer in water pipes and suspension of water supply. To prevent these problems of small hydropower generator, we has analyzed water supply patterns, installation position and water pipe systems.