• 설비공학논문집
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• 제9권4호
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• pp.504-516
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• 1997

Recently scientists and engineers are developing a system to get waste heat of low-temperature level with advanced heat pump, which have not been used up to now. As the reason, it is necessary to examine capability of using waste heat which is raised up in the tunnel of subway out of widely distributed low-temperature waste heat in large cities. Therefore we surveyed thermal environment of the tunnel of subway in $S\check{o}my\check{o}n$, downtown of Pusan, from November 1995 to December 1996 and developed a program to predict the thermal environment of subway on the basis of experimental data and the geometries of tunnels. This paper has proved availability of waste heat of subway when the measured results obtained in subway in the winter time and the simulated results of thermal environment prediction program are compared, as well as has reported results of estimating reliability of the simulation program. As the result, the charateristics of thermal environment in the tunnel of subway in $S\check{o}my\check{o}n$ station in the winter time are to be followed; 1) temperature in the tunnel is about $10^{\circ}C$ higher than outside air temperature, 2) temperature change in the tunnel is less than that in the platform so that we may obtain stable heat source, 3) and when the measured results obtained in subway in the winter time and the simulated results of thermal environment prodiction program is compared, both results show similar tendency. Therefore, we confirm estimating reliability of the simulation program.

• Journal of Advanced Marine Engineering and Technology
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• 제30권2호
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• pp.253-259
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• 2006

There is few study which automatically diagnoses the fault from ship's monitored data. The bigger control and monitoring system is. the more important fault diagnosis and maintenance is to reduce damage caused by system fault. This paper proposes fault diagnosis system using a correlation analysis algorithm which is able to diagnose and forecast the fault from monitored data and is composed of fault detection knowledge base and fault diagnosis knowledge base. For all kinds of ship's engine room monitored data are classified with combustion subsystem, heat exchange subsystem and electric motor and pump subsystem, To verify capability of fault detection, diagnosis and prediction, FMS(Fault Management System) is developed by C++. Simulation by FMS is carried out with population data set made by the log book data of 2 months duration from a large full container ship of H shipping company.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.251-256
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• 2005

There is few study which automatically diagnose the fault from ship's monitored signal. The bigger control and monitoring system is, the more important fault diagnosis and maintenance is to reduce damage brought forth by system fault. This paper proposes fault diagnosis system using a correlation analysis algorithm which is able to diagnose and forecast the fault and is composed to fault detection knowledge base and fault diagnosis knowledge base. For this all kinds of ship's engine room monitored data are classified with combustion subsystem, heat exchange subsystem and electric motor and pump subsystem by analyzing ship's operation data. To verifying capability of fault detection, diagnosis and prediction, Fault Management System(FMS) is developed by C++. Simulation experiment by FMS is carried out with population data set made by log book data of 2 months duration from a large full container ship of H shipping company.

• 한국지반공학회논문집
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• 제26권2호
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• pp.45-54
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• 2010

본 논문에서는 동반논문에서 구축된 수치해석 모델을 이용하여 SCW의 성능을 평가하기 위한 매개변수연구를 수행하였다. 매개변수연구에는 공극률, 투수계수, 열전도도, 비열, 지열경사 등 5개의 지반환경변수와 유량, 심정심도, 심정직경, 유입관 직경, 블리딩율의 설계변수가 적용되었다. 수치해석은 24시간 연속가동과 가동 중지를 반복하는 14일간의 가동 두 가지로 수행되었다. 해석결과 SCW 성능에 중요한 영향을 미치는 변수는 열전도도, 수리전도도, 지열경사, 유량, 심정 심도, 블리딩율인 것으로 나타났다. 열전도도가 높을수록 SCW의 효율이 향상되는 것으로 나타났다. 지열경사가 클수록 심정 저부의 온도가 증가하여 난방모드에서는 효율이 향상되지만, 냉방모드에서는 유입수의 온도가 증가하여 오히려 효율이 감소하는 것으로 나타났다. 수리전도도도는 $10^{-4}m/s$ 이상일 경우에는 큰 영향을 미칠 수 있으나 $10^{-6}m/s$ 이하에서는 영향이 적은 것으로 나타났다. 심정심도가 증가할수록 SCW의 효율이 향상되는 것으로 나타났지만 심정심도를 높일수록 시공비가 증가하게 된다. 블리딩을 적용하며 추가적인 비용 없이 심정온도를 조절할 수 있으며 성능을 향상시킬 수 있는 매우 효과적인 방법인 것으로 나타났다. 단, 블리딩은 유출수를 배출할 공간이 확보되며 지하수량이 풍부한 경우에만 적용할 수 있다. 본 매개변수 연구결과, SCW의 성능에 영향을 미치는 요소는 매우 다양하며 이들의 복합적인 영향을 정확하게 규명하기 위해서는 수치적 모델을 수행해야 할 필요가 있는 것으로 나타났다.

• 한국지열·수열에너지학회논문집
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• 제6권2호
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• pp.1-7
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• 2010

The objective of this study is to find the optimal control algorithm of a hybrid Plant, which is combined by renewable energy plant of the GSHP(Geothermal Source Heat Pump) and the normal plant (Chiller, boiler). The work presented in this study was carried out in the EnergyPlus(Version 2.0). The EnergyPlus was modified in order to simulate the hybrid plant. The plant system was controlled by the load-range-based operation in which schemes select a user specified set of equipment for each user specified range of a particular simulation condition. In the use of the load-range-based operation, four kind of control cases were defined and simulated in order to obtain the optimal control algorithm of the hybrid plant. The result showed that the Case 2 was the optimal control algorithm which used the GSHP as a base operating plant and the normal plant as an assistant operating plant. Even though the normal plant was operated in full load and the renewable energy plant of the GSHP was operated in partial load, the annual energy consumption of the normal plant was larger than that of the GSHP plant.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1277-1282
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• 2009

The main objective of this prototype is to control resonance frequency of DTL system through the temperature control of cooling water. It is to resonant frequency of the drift tube cavities to 350 MHz. This paper describes the design of a prototype cooling water skid required for the temperature control of the DTL cavities, focusing in the modeling and simulation of the cooling system, the sizing of water pumping skid component.

• 한국전기전자재료학회논문지
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• 제28권4호
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• pp.262-270
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• 2015

In this paper existing buildings, not a new buildings and house for living people not just a displaying and a viewing, created by the imagine effect or virtual simulation was applied various Active and Passive elements. After constructing zero-energy houses, through default case happened during operation period it is described problems and solutions about field part, work classification, installation by Location part, and Installation equipment part. Since then, to take advantage of this thesis, it's the purpose of this paper using as the baseline data for building a zero-energy house in another similar case.

• 한국지열·수열에너지학회논문집
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• 제6권2호
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• pp.15-22
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• 2010

The natural refrigerants have used into HVAC equipments because the CFCs and HFCs have some environmental problems like high ODP and GWP. The carbon dioxide has small effect on the environmental problem but also good thermodynamics properties. In this study, the simulation study on the performance and characteristics of a $CO_2$ gascooler and evaporator using a fin-tube and microchannel heat exchanger has been conducted. Besides, the comparison of performance with operating condition was carried out in order to apply to the $CO_2$ heat pump system. As a result, the front sizes of a gascooler and evaporator using a microchannel were decreased by 63% and 58%, respectively, compared to those using a fin-tube. The performance of the fin-tube gascooler and evaporator were more responsive to the variation of operating conditions compared to that of microchannel. The pressure drop of a fin-tube heat exchanger was higher than that of a microchannel one.

• 드라이브 ㆍ 컨트롤
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• 제16권4호
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• pp.38-47
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• 2019

In this paper, a real-time simulation model of an excavator using Amesim was proposed, considered the operation of functional valves with the main control valve (MCV). The hydraulic system models including the pump and MCV have been developed. The kinematic and dynamic models of the manipulator have also been developed, to confirm the behavior of the excavator. The MCV model includes various functional valves such as the regenerative valves, holding valves, swing and boom priority valves, and regen-cut valves so that simulations similar to real excavators can be performed. Additionally, to obtain the real-time calculation performance, the parts with no major influence on the dynamic behavior were simplified, high frequency factors were removed, and parameters were optimized. The models were compared with each other through the numerical analysis with variable time-step and fixed time-step, and the results were verified by comparison with the results of the actual vehicle tests.

• 설비공학논문집
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• 제28권10호
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• pp.402-407
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• 2016

Ground-coupled heat pump systems have been widely used, as they are regarded as a renewable energy source and ensure a high annual efficiency. Among the system components, borehole heat exchangers (BHE) play an important role in decreasing the entering water temperature (EWT) to heat pumps in the cooling season, and consequently improve the COP. The optimal sizing of the BHEs is crucial for a successful project. Other than the existing sizing methods, a simulation-based design tool is more applicable for modern complex geothermal systems, and it may also be useful since design and engineering works operate on the same platform. A simulation-based sizing method is proposed in this study using the well-known Duct STorage (DST) model in Trnsys. TRNOPT, the Trnsys optimization tool, is used to search for an optimal value of the length of BHEs under given ground loads and ground properties. The result shows that a maximum EWT of BHEs during a design period (10 years) successfully approaches the design EWT while providing an optimal BHE length. Compared to the existing design tool, very similar lengths are calculated by both methods with a small error of 1.07%.