• Geomechanics and Engineering
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• 제38권5호
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• pp.497-505
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• 2024

The power plant is a major infrastructure composed of essential machinery such as Turbine Generators (TG), Heat Recovery Steam Generators (HRSG), etc. Particularly, Combined Heat & Power Plants (CHP) are highly efficient power plants that simultaneously produce heat and electricity. Recently, cases have emerged where railway tunnels are being constructed beneath such power plants due to the underground development of urban rail transportation. Therefore, there is a pressing need to assess the impact of vibrations induced by blasting excavation during the construction of railway tunnels beneath the power plant, as well as the vibrations during railway operation, on the major machinery foundations and structures within the power plant. In this study, criteria for evaluating the vibration impact on key vibration-sensitive structures are summarized, and evaluation standards based on international criteria are established. Based on this, the study examines the vibration impact during the blasting excavation method of NATM tunnels beneath the operational power plant. Furthermore, subsequent railway operation, specifically focusing on the impact of train vibrations on Turbine foundations, Pump foundations, and District Heating pipelines using 3D dynamic numerical analysis. The results indicate that vibration values corresponding to up to 97.3% of the evaluation criteria are derived based on the numerical analysis. However, considering the significance of power plant-related structures, additional measures to reduce vibrations are proposed, including further test blasting, alteration of blasting patterns, reducing the charge per delay, or decreasing advance.

• 플랜트 저널
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• 제10권4호
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• pp.35-41
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• 2014

축열조는 집단에너지를 공급하는 지역의 고도와 열부하에 따라 높이와 용량이 결정된다. 이는 축열조의 수두를 이용하여 열배관망에 압력을 가하고 배관망내의 비등을 방지하며 온도변화에 따라 체적이 팽창하면 이를 흡수하고 수축 시에는 부족한 중온수를 배관망에 공급하는 기능을 해야 하기 때문이다. 또한, 축열조의 역할은 주로 열수요량의 변화가 심한 계절별 주간 야간 시간대에 적절한 용량을 갖추고 잉여 열량을 저장한 후 필요한 시간대에 지역난방 열원으로 이용하면 열생산 설비의 운전 조건에 영향을 받지 않으면서 독자적으로 지역난방 열수요를 공급할 수 있는 장점이 있다. 본 연구는 지역난방에 건설되어 운영 중인 축열조 27기 중 폴리우레탄 폼의 단열 재료로 시공된 18기의 축열조에 대하여 단열재의 재질과 축열조의 운전방법에 따른 단열재의 손상원인에 대한 고찰과 단열재 손상이 축열조 부식에 어떠한 영향을 미치는지 고찰하였다.

• 설비공학논문집
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• 제25권11호
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• pp.585-594
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• 2013

In this study, we developed a heat supply control algorithm that minimizes the heat loss in the heat distribution pipelines used for supplying heat energy to shared group housing. Controlling the temperature and flow rate of the hot water supplied to the heat exchanger for shared group housing enables us to develop a heat supply control technique that meets the heating load required by each household in a shared apartment building in accordance with changes in the outdoor air temperature, and that minimizes the heat loss occurring in the heat distribution pipeline. A one-year study in 2008 on a 1,473-household D-apartment building in Hwaseong, Gyeonggi-do, South Korea, compared the heat capacity used by each household, as well as the heat capacity supplied to the heat exchanger room of the apartment housing building, to calculate the amount of heat loss in the heat distribution pipeline. The results confirmed that 24.1% of the heat supplied was lost in the piping.

• 한국재료학회지
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• 제12권2호
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• pp.103-111
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• 2002

The thermally insulated underground pipelines have been used for district heating system. The sensor wire embedded in the insulation was used for monitoring the insulating resistance between the sensor wire and the pipe. The resistance measurement system detects corrosion of steel pipe under insulation. The corrosion and stress corrosion cracking(SCC) characteristics of sensor wire in synthetic ground water were investigated using the electrochemical methods and constant load SCC tests. The polarization tests were used to study the electrochemical behavior of sensor wire. The sensor wire was passivated at temperatures ranging from 25 to $95^{\circ}C$. However, the applied sensing current larger than passive current resulted in breakdown of passive film. The constant load SCC tests were performed to investigate the effects of applied current and load on the fracture behavior. Stress-corrosion cracks initiated at pits that were produced by sensing current. The growth of the pit involves a tunnelling mechanism, which leads to ductile fracture.