• 한국산업정보학회논문지
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• 제23권3호
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• pp.25-34
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• 2018

본 논문은 세탁물 건조기의 고효율과 건조성능 향상을 위한 탄소나노섬유의 열원(히팅모듈)을 설명하였고, 이 열원의 적용 가능성을 평가하는데 집중하였다. 제안된 히팅모듈의 설계를 위해, 탄소나노섬유램프의 표면온도와 표면온도분포특성에 관한 실험이 수행되었다. 그 램프의 표면온도는 램프에 흐르는 전류의 증가와 함께 선형적으로 증가하였고, 그 램프의 길이가 짧을수록 증가하는 패턴을 보였다. 제안된 히팅모듈은 건조효율, 세탁물의 수분증발률, 건조동작 중 드럼의 내부온도를 기반으로 평가되었다. 건조효율은 KS C 9319의 기준인 45%를 충족하였고, 수분증발률과 드럼의 내부온도는 각각 98.88%와 평균 $61.1^{\circ}C$로 S사의 제품과 대등한 건조성능을 보였다. 그 평가와 실제 건조실험 결과로부터, 제안된 탄소나노섬유램프 히팅모듈은 건조효율과 건조성능의 측면에서 세탁물 건조기의 열원으로 적용 가능할 것으로 판단되며, 높은 온도의 열원, 우수한 발열량, 원적외선 방출에 의한 건조성능의 향상과 세탁물의 살균효과를 얻을 수 있다. 추가적으로, 그 건조기들 사이에 건조효율 성능차이가 열원의 소비전력을 기반으로 상세히 분석되었다.

• 수산해양교육연구
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• 제21권3호
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• pp.400-408
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• 2009

The purpose of this study is to know the concept of Eco-industrial Park and How to use the thermal effluents from power plants. Thermal effluents, which use sea water for cooling, from power plants have been discharged with about $6{\sim}7^{\circ}C$ higher temperature than near sea area. Therefore, it could effect on the marine ecosystem as a external pressure factor that increase the artificial thermal load in near sea area. The applications of thermal effluents had been surveyed through the several internal and external cases for utilizing heat sources and reducing the thermal load. As the precedence research for applying, the amount of heat sources of thermal effluents was evaluated. When the thermal effluents was fully applied in heat sources and available heat, assume that use heating season by 12 hours a day of demanded available heat, it was possible to calculate total 198 Tcal of energy saving.

• Geomechanics and Engineering
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• 제37권6호
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• pp.591-597
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• 2024

The purpose of this paper is to depict the effect of gravity on a nonlocal thermoelastic medium with initial stress. The Lord-Shulman and Green-Lindsay theories with fractional derivative order serve as the foundation for the formulation of the fundamental equations for the problem. To address the problem and acquire the exact expressions of physical fields, appropriate non-dimensional variables and normal mode analysis are used. MATLAB software is used for numerical calculations. The projected outcomes in the presence and absence of the gravitational field, along with a nonlocal parameter, are compared. Additional comparisons are made for various fractional derivative order values. It is evident that the variation of physical variables is significantly influenced by the fractional derivative order, nonlocal parameter and gravity field.

• 한국가시화정보학회지
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• 제21권3호
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• pp.57-64
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• 2023

An open pulsating heat pipe operates continuously by inflow and outflow fluids through an open-type condenser. The open pulsating heat pipe is a device capable of obtaining the thrust due to the variation of internal pressure during phase change. Therefore, the open pulsating heat pipe is a suitable device to move fluids if the heat source such as waste heat exists. Many numerical studies have not been sufficiently conducted on the open pulsating heat pipe. In this study, the numerical analysis of the open pulsating heat pipe is performed according to the length of the condenser section. The OpenFOAM software is used to obtain the thrust and the flow visualization for the open pulsating heat pipe.

• 대한기계학회논문집B
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• 제40권12호
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• pp.793-799
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• 2016

폐열을 열원으로 사용하는 저온형 개질기는 하이브리드 연료전지 시스템의 효율향상을 위해 사용되고 있다. 저온형 개질기의 경우 저온의 열적상태에서 높은 열전달 효율을 내는 것이 중요하며, 이를 위한 형상 최적화의 과정이 필요하다. 본 연구에서는 제한된 열공급 상황에서 개질기의 형상인자 변화에 따른 온도 및 반응특성을 전산해석을 통하여 알아보고자 하였다. 해석결과 저온형 개질기의 반응이 활발히 일어나는 영역은 온도가 높은 후단에 제한되는 현상을 보여 고온형 개질기와의 차이를 나타내었다. 또한 개질기의 기체공간속도(Gas hourly space velocity, GHSV)를 감소시키거나 열전달 면적을 증대시킴으로써 효율을 향상 시킬 수 있음을 확인하였고 종횡비에 따른 해석을 실시한 결과 저온형 개질기의 경우 길이방향보다는 반경방향의 열전달을 증대시키는 방법이 효과적임을 확인하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제13권5호통권57호
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• pp.169-179
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• 2009

본 논문의 목적은 열화상 비파괴 검사기법을 적용시 손상된 콘크리트 구조물의 표면온도를 증폭시키기 위해 사용되는 외부 열원의 효율성을 알아보기 위함이다. 원적외선램프와 할로겐램프의 적용성과 효율성을 서로 비교하였다. 이를 위해 전술한 두 개의 열원을 콘크리트의 내부공극과 FRP쉬트의 비부착 결함 시험체에 적용하였다. 본 연구결과, 원적외선램프가 할로겐램프보다 더 효율적인 것으로 파악되었다. 또한, 손상영역을 효과적으로 검출하기위해서 가우스 필터와 프리윗 마스크 화상처리기법을 혼합한 알고리즘을 제안하였다.

• 한국전산유체공학회지
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• 제14권1호
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• pp.9-17
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• 2009

In this study we investigated the characteristics of fluid flow and heat transfer within a coolant passage in the cylinder head assembly of an internal combustion engine by using a commercial CFD code, CFX The complex coolant passage of the cylinder head assembly was modelled by suitable choice of a grid system and careful attention was paid in the construction of meshes near the walls where significant cooling occurs. To treat the simultaneous heating and cooling of the combustion walls we invented a methodology allowing a heat source within the solid wall and the convective cooling at the interface between the solid and the fluid. We managed to reproduce the experimental results by adjusting parameters appropriately. We have found that high temperature was concentrated at the surface of the cylinder jacket. It turned out that the effect of oil cooling from the piston head was unexpectedly significant. On the other hand the effect of cooling from the ambient air is almost negligible. The CFD method proposed in this study is believed to be useful in the early stage of the design of the engine-cooling system.

• 대한건축학회논문집:구조계
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• 제34권10호
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• pp.19-26
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• 2018

The purpose of this study was to analyze characteristics and to develop estimation model of IHG(Internal Heat Gain) from appliance in domestic apartment units. To do this, it was defined the source of IHG from appliance and the calculation method through the case study of international and domestic codes. And the equipment related datum such possession, usage or not, etc were collected through field survey in apartment units, and the appliances' electricity consumption were measured separately from overall electricity consumption. Annual electricity consumption value were calculated with field survey datum and appliances' electricity consumption measurement datum, and then IHG value was calculated by applying PHPP v9 method. And it was conducted correlation analysis between IHG value and the area for exclusive use, the number of occupants, and then the IHG from applianace estimation model was deducted with regression analysis. Finally, it was analyzed the present level and of the domestic code(The Building Energy Efficiency Rating System) comparing with the value of estimation model, and the various international codes(HERS, Building America, SAP).

• Journal of applied mathematics & informatics
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• 제15권1_2호
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• pp.127-146
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• 2004

In this paper we consider a heat flow in an inhomogeneous. body without internal source. There exists special initial and boundary conditions in this system and we intend to find a convenient coefficient of heat conduction for this body so that body cool off as much as possible after definite time. We consider this problem in a general form as an optimal control problem which coefficient of heat conduction is optimal function. Then we replace this problem by another in which we seek to minimize a linear form over a subset of the product of two measures space defined by linear equalities. Then we construct an approximately optimal control.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.395-398
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• 1997

In the modem manufacturing system, to achieve the unmanned automation, the stability of accuracy is required through a long working period. The thermal deformation of precision machine is predominant in this long time stability. While grinding slender and long workpiece at cylindrical grinding machine, we support workpiece using steadies to prevent the vibration of workpiece. The thermal deformation of the machine by grinding and internal heat source cause processing errors, so the steadies for compensating the thermal deformation in real time are strongly needed. In order to compensate these thermal deformation and grinding processing errors, the device to determine the precise positioning having the stroke of 10.mu.m is necessary. This paper suggests design and make the device to determine the precise positioning using thermoelectric device, to investigate the control characteristics and presents the heat actuator will be very useful in machine tool.