• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.10a
• /
• pp.711-712
• /
• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.10a
• /
• pp.380-384
• /
• 2010

A disturbance flow at piping bands and discontinuous regions such as a valve, a header has a intense broadband internal pressure field and a sound field which are propagated through the piping system The fields becomes the source of a vibration of this piping system. Intense broadband disturbance flow at a discontinuous region such as elbows, valves or headers generates an acoustical pulsation. The pulsation becomes the source of structural vibration at the piping system. If it coincides with the natural frequency of the pipe system, excessive vibration results. High-level vibration due to the pressure pulsation affects the reliability of the plant piping system. This paper discusses the high vibration and the branch vent pipe's failure of condensate-water supply piping system due to the effect of acoustical pulsations by flow turbulence from the flow control valves of globe type in a power site.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11a
• /
• pp.360.2-360
• /
• 2002

There was the transient vibration on $H_2$ piping system fer cooling the generator in a power plant. We found it was resulted from resonance between the natural vibration of the piping system and exciting force from the turbine rotor by measurement and simulation test. We verified it would be changed the mode shape of the piping system by several simulation test for the structural modification of the piping system. (omitted)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• pp.975-978
• /
• 2004

There was transient vibration on the piping system from #4 heater to the deaerator in a power plant. We found it was resulted from resonance between the natural vibration of the piping system and vibration induced by flow of feedwater. We verified it would reduce vibration by increasing stiffness of the piping system. Therefore we concluded that it would be generally better to increase stiffness of the piping system to reduce vibration amplitude of 10Hz low for big sized piping systems.

• Product Safety
• /
• s.249
• /
• pp.44-47
• /
• 2014

두리화학(주)는 1974년 모체 공장인 대성화학을 창립한 이래 플라스틱 배관자재 생산 전문업체로 성장 발전해 왔다. 그동안 고객의 욕구를 충족시키고 고객 감동경영을 실현하기 위해 부단히 노력해온 두리화학(주)는, 최근 공동주택 배관 시스템의 최대 결점인 배수 소음 및 결로를 별도의 방음 및 보온 작업을 하지 않고도 배수소음 및 결로를 획기적으로 줄일 수 있는 공법을 개발하여, 국내 유수의 건설 업체에 납품하여 뛰어난 성능을 인정받게 되었다. 동종업계에서 국내 최대의 생산 설비와자동화 제조 공정을 갖추고 최고의 품질관리 시스템을 가동하여, 부적합품 발생 방지에 주력하고 있으며 사후 관리에도 만전을 기하고 있다. 또한 두리화학(주)는 기업의 최대 목적인 이윤을 추구함에 있어 사회적 책임을 다하고, "고객감동경영"의 경영철학을 바탕으로 무한경쟁시대의 21세기를 맞아, 항상 고객과 함께 연구하고 발전하는 기업으로 거듭날 것을 고객 앞에 다짐한다.

• Product Safety
• /
• s.246
• /
• pp.40-43
• /
• 2014

두리화학(주)는 1974년 모체 공장인 대성화학을 창립한 이래 플라스틱 배관자재 생산 전문업체로 성장 발전해 왔다. 그동안 고객의 욕구를 충족시키고 고객 감동경영을 실현하기 위해 부단히 노력해 온 두리화학(주)는, 최근 공동주택 배관시스템의 최대 결점인 배수 소음 및 결로를 별도의 방음 및 보온 작업을 하지 않고도 배수 소음 및 결로를 획기적으로 줄일 수 있는 공법을 개발하여, 국내 유수의 건설 업체에 납품하여 뛰어난 성능을 인정받게 되었다. 동종업계에서 국내 최대의 생산 설비와 자동화 제조 공정을 갖추고 최고의 품질관리 시스템을 가동하여, 부적합품 발생방지에 주력하고 있으며 사후 관리에도 만전을 기하고 있다. 또한 두리화학(주)는 기업의 최대 목적인 이윤을 추구함에 있어 사회적 책임을 다하고 "고객감동경영"의 경영철학을 바탕으로 무한 경쟁시대의 21세기를 맞아, 항상 고객과 함께 연구하고 발전하는 기업으로 거듭날 것을 다짐했다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.05a
• /
• pp.84-85
• /
• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.837-838
• /
• 2014

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.577-578
• /
• 2014

• The Journal of the Acoustical Society of Korea
• /
• v.41 no.6
• /
• pp.705-712
• /
• 2022

A sudden pressure drop caused by the pressure relief valve acts as a strong noise source and propagates the compressible pressure fluctuation along the pipe wall, which becomes a excitation source of Acoustic Induced Vibration (AIV). Therefore, in this study, the numerical methodology is developed to evaluate the reduction effect of compressible pressure fluctuation due to curved pipe in the pressure relief valve system. To describe the acoustic wave caused by density fluctuation, unsteady compressible Large Eddy Simulation (LES) technique, which is high accuracy numerical method, Smagorinsky-Lilly subgrid scale model is applied. Wavenumber-frequency analysis is performed to extract the compressible pressure fluctuation component, which is propagated along the pipe, from the flow field, and it is based on the wall pressure on the upstream and downstream pipe from the curved pipe. It is shown that the plane wave and the 1st mode component in radial direction are dominant along the downstream direction, and the overall acoustic power was reduced by 3 dB through the curved pipe. From these results, the noise reduction effect caused by curved pipe is confirmed.