• Journal of Korea Society of Industrial Information Systems
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• v.23 no.3
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• pp.25-34
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• 2018

This paper presents a heating source of carbon nanofibers for the efficiency and the drying performance of laundry dryer, and focuses on the applicability-evaluation of its source. To design the proposed heating module, experiments were conducted in terms of surface temperature and surface temperature distribution characteristics of carbon nanofiber lamps. The surface temperature of the lamps increased linearly with increment of a current to flow a lamp and revealing the increasing pattern as the length of the ramps is shorter. The proposed heating source was evaluated based on drying efficiency, moisture evaporation rate at laundry, and internal temperature of a drum during drying process. The drying efficiency satisfied a 45% which is specified in KS C 9319. The moisture evaporation rate and the internal temperature of the drum were respectively 98.88% and $61.1^{\circ}C$, which are similar to that of S's company dryer. From the evaluation and actual drying test results, the proposed carbon nanofiber lamp heating module is considered to be applicable as a heat source for laundry dryer in terms of drying efficiency and drying performance. it is possible to obtain a heat source at a high temperature, an excellent calorific value, an improvement in drying performance, and an effect of sterilizing laundry due to the emission of far-infrared rays. In addition to the applicability, the difference of the drying efficiency between the dryers was analyzed in detail based on the power consumption of the heat sources.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.219-221
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• 2009

본 논문에서는 전기설비의 전기적 접속부 또는 전기배선 등에서 발생하는 발열상태를 실시 간으로 모니터링하는 전력설비 진단시스템에 사용되고 있는 광온도센서에 대하여 열원에 따른 동작특성을 실험, 분석하였다. Heimann Sensor사의 광온도소자를 이용하여 광온도센서를 제작하여 실험에 사용하였으며, 열원으로는 Black Body와 Hot Plate를 사용하였으며 각각에서의 열원의 온도변화에 따른 광온도센서의 출력전압값을 측정, 비교 분석하였다. 실험결과, Black Body에 의한 온도 측정이 Hot Plate에서보다 더 정밀함을 확인할 수 있었다. 이러한 분석 결과는 향후, 전력설비 진단시스템의 현장 적용에 있어 광온도센서의 출력값과 실측값의 매칭을 위한 기본 자료가 될것으로 기대된다.

• Journal of Welding and Joining
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• v.22 no.2
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• pp.1-2
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• 2004

강구조물 제작시 용접프로세스에 의해 용접부 근방에서는 용접열원에 의해 급속가열ㆍ급속냉각의 열 사이클을 받으며, 열원의 이동과 함께 온도장이 변화하므로 용접부에 불균일한 온도분포가 발생된다. 이러한 불균일한 온도분포에 의한 용접부 근방의 열팽창ㆍ수축을 용접부로부터 떨어져 있는 저온상태의 부재가 이를 구속하여 결과적으로 용접변형과 잔류응력이 발생한다.(중략)

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.4
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• pp.907-911
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• 1990

본 연구에서는 비열이 일정하고 초기온도가 주어진 열원으로부터, 일정한 열 전달 용량의 열교환기를 사용하여 최대의 에너지를 전달시키기 위한 조건을 구해 보기 로 한다. 즉, 저온유동은 고온의 열원유동과 대항류로서 열교환하며 위치에 따라 저 온유체의 온도가 가역 단열압축 또는 팽창에 의하여 임의로 조절될 수 있는 일반적인 경우에 대하여, 저온유체가 최대의 가용 에너지를 흡수하기 위한 온도분포를 변분법 문제로서 해석하고 그에 다른 부수조건들을 검토하고자 한다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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• pp.165-170
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• 1999

기계적 증기재압축(Mechanical Vapor Recompression) 시스템은 증기를 압축하여 압력을 올리면 온도가 상승하는 원리를 이용한 것으로서 시스템의 최종 증발관에서 발생한 저온의 증발증기를 전량 증기압축기로 압축ㆍ승온하여 자신의 최초 증발관의 가열 열원으로 재사용 하는 방식이다. 따라서 이 사이클에 필요한 보충열원은 가열측과 증발측과의 온도상승분 만큼만 증기의 포화온도를 올리면 되므로 에너지절약 효과가 매우 크다.(중략)

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.10
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• pp.919-926
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• 2013

Experiments were conducted to determine the operating characteristics of a small-scale ORC (organic Rankine cycle) system for various low-temperature heat sources. A small-scale ORC power generation system adopting R-245fa as a working fluid was designed and manufactured. Hot water was used as the heat source, and the temperature was controlled using 110-kW electric resistance heaters that provided temperatures of up to $150^{\circ}C$. An open-drive oil-free scroll expander directly connected to a synchronous generator was installed in the ORC unit. Experiments were conducted by varying the rotational speed of the expander under the same heat source temperature conditions. The factors that influence the performance of the small-scale ORC system were analyzed and discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5C
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• pp.177-183
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• 2012

The use of energy pile foundation has been increased for economic utilization of geothermal energy. In particular, a coil-shaped ground heat exchanger (GHE) is preferred than conventional U-shaped heat exchanger to ensure better efficiency of heat exchange rate. This paper presents experimental results by changing different pitch spaces of spiral coils. Joomunjin sand was filled in a steel box of which the size was $5m{\times}1m{\times}1m$. Thermal response tests (TRTs) were conducted to measure the ground thermal conductivity with temperatures of circulating water using line source model and ring coil model. Experimental results and analytical solutions were compared to validate the applicability of these models. Ring coil model showed more accurate similar results with experimental data rather than line source model and cylindrical source model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.725-731
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• 2016

This study numerically investigates the thermal performance of a 2.0-kW butane-based combustion heating system for an electric vehicle under cold conditions. The system is used for cabin space heating and coolant-based battery thermal management. ANSYS CFX 17 software was used for parametric analysis. The mass flow rates of cold air and coolant were varied, and their effects were compared. The numerical results were validated with theoretical studies, which showed an error of 0.15%. As the outside air mass flow rates were increased to 0.005, 0.01, and 0.015 kg/s, the cabin supply air temperature decreased continuously while the coolant outlet temperature increased. When the coolant mass flow rates were increased to 0.005, 0.01 and 0.015 kg/s, the air temperature increased while the coolant outlet temperatures decreased. The optimal mass flow rates are discussed in a consideration of the requirements for high cabin heating capacity and efficient battery thermal management.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.96-102
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• 2019

The study of thermal effect on the structure is carried out in the case of Guss asphalt which is paved at the temperature of $240^{\circ}C$ or higher in the bridge pavement of the steel deck bridges. However, studies on the heat source data applicable to numerical analysis are insufficient, the temperature load is used as a joint load. In this study, the heat source equations that can be directly loaded on the plate elements, although limited, are presented using the measured temperature data in the Guss asphalt pavement and its validity is confirmed by a brief numerical analysis.

• Journal of Energy Engineering
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• v.19 no.3
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• pp.143-150
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• 2010

Line source method of borehole system assumes the entire surrounding medium is uniform. However, thermal properties of grouting region are considerably different from those of surrounding soil. In this study we investigate the effect of grouting materials on the solution of line source method with the aid of numerical analysis. This numerical model generates the temperature of borehole fluid with which line source solution can be obtained. Then this solution can be compared with input condition of numerical model. The results of this comparison show that thermal conductivity and borehole thermal resistance of line source solution are approximately 86% and 91% of the input condition of numerical model. Chart method is developed in this study to find the numerical input conditions (thermal conductivity and borehole thermal resistance) from the line source solution. Thermal response test of test borehole is conducted, the results of which are approximately consistent with the Chart method. Thermal property changes of grouting materials on the line source solution are also examined.