• 한국주거학회논문집
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• 제1권1호
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• pp.91-102
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• 1990

The aim of this study is to discover thermal characteristics of Ondol heating systems. The housing subjected was categorized into detached single family houses and apartments, reinforced concrete and brick structures, intermittent and continous heating system, and the space subjected was bedroom. In order to understand the thermal characteristics of each floor heating systems, the vertical distribution of indoor temperature and the distribution of surface temperature on the floor were measured. The vertical distribution of indoor temperature except the measurement point 1 largely showed average temperature distribution, and the temperature of the measurement point 1 in the housing surveyed showed the highest temperature in the house "sample A" because of the radiation heating from the floor of the Ondol room. As the result of the measurement, the thermal characteristics of each heating system were more stable distribution in apartments of R.C structure.structure.

• Journal of Welding and Joining
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• 제19권5호
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• pp.526-533
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• 2001

Induction heating of float metal products has an increasing importance in many applications, because it generates the heat within workpiece itself and provides high power densities and productivity. In this study, the induction heating of a steel plate to simulate the line heating is investigated by means of the Finite Element Analysis of the magnetic field and temperature distribution. A numerical model is used to calculate temperature distribution within the steel plate during the induction heating with a specially designed inductor. The effects of materital properties depending on the temperature and magnetic field are taken into consideration in an iterative manner. The simulation results show good magnetic field with experimental data and provide good understanding of the process. Since the numerical model demonstrates to be suitable for analysis of induction heating process, the effects of air gap and frequency on magnetic-flux and power-density distribution are also investigated. It is revealed that these process parameters have an important roles on the electro-magnetic field and power-density distribution governing the temperature distribution of the plate.

• Journal of Advanced Marine Engineering and Technology
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• 제34권5호
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• pp.617-624
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• 2010

선박 건조공정에서 외피의 곡면 가공에 많이 사용하는 가공법을 선상가열법이라고 한다. 선상가열법은 엔지니어의 숙련도에 따라 품질의 차이가 커지기 때문에 현재에는 엔지니어의 숙련도에 의존하지 않는 자동화기기를 사용하여 선상가열을 수행하는 경우가 많다. 본 연구에서는 자동화기기를 사용한 선상가열에 의한 가열판재의 온도분포를 조사하고자 한다. 선상가열시 적용되는 주요한 변수는 가열원의 이동속도, 강도 및 가열 방식 등이 있으며, 본 연구에서는 세 가지 변수를 중심으로 가열판재의 표면 및 내부온도가 어떻게 변화하는지를 조사하였다. 해석결과 가열원의 이동속도가 빨라질수록 판재의 피크온도는 낮게 형성되는 것을 확인하였고, 또한 열원의 크기에 따른 피크온도 및 온도분포가 선형적으로 변화하는 것을 정량적으로 계산할 수 있었다.

• 한국정밀공학회지
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• 제22권1호
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• pp.97-102
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• 2005

The procedure of semi-solid forming is composed of heating a billet, forming, compression holding and ejecting step. There are several methods to heat a billet during semi-solid forming process such as electric heating and induction heating. Usually in semi-solid forming process, induction heating has been adopted to achieve more uniform temperature of semi-solid material. Although induction heating is better method than any others, however, there is still difference of temperature between internal part and surface part of semi-solid material. Worse yet, in case of high liquid fraction of semi-solid material, liquid of the billet will flow down though solid of the billet still remains, which is very difficult to handle. In the present study, induction heating of semi-solid material with compulsive surface cooling has been performed to obtain uniform distribution of temperature. Distribution of temperature of the billets was measured and compared with that of conventional distribution of temperature. By this new induction heating method, not only temperature over the whole billet become uniform, but also control of temperature is possible.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.465-468
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• 2000

The procedure of semi-solid forming is composed of heating a billet, forming, compression holding and ejecting step. There are several methods to heat a billet during semi-solid forming process such as electric heating and induction heating. Usually in semi-solid forming process, induction heating has been adopted to achieve more uniform temperature of semi-solid material. Although induction heating is better method than any others, however, there is still difference of temperature between internal part and surface part of semi-solid material. Worse yet, in case of high liquid fraction of semi-solid material, liquid of the billet will flow down though solid of the billet still remains, which is very difficult to handle. In the present study, induction heating of semi-solid material with compulsive surface cooling has been performed to obtain uniform distribution of temperature. Distribution of temperature of the billets was measured and compared with that of conventional distribution of temperature. By this new induction heating method, not only temperature over the whole billet become uniform, but also control of temperature is possible.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권5호
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• pp.327-337
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• 2000

In this paper, the design sensitivity formula for the control of the transient temperature distribution is developed using the direct differentiation method, and used for the optimal design of induction heating coil position. The temperature distribution is calculated using the heat source of the induced eddy current and heat diffusion equation. The physical property variations of the workpiece depending on the temperature are considered. The eddy current distribution and the temperature distribution are calculated with the 2D finite element procedure. The adjoint variable technique is employed in expressing the design sensitivity. The goal of the design is to have the desired distribution of the temperature on a specific region of the sensitivity. The goal of the design is to have the desired distribution of the temperature on a specific region sensitivity. The goal of the design is to have the desired distribution of the temperature on a specific region of the workpiece. The numerical example shows that the proposed design sensitivity analysis for the control of the transient temperature distribution is very useful and practical in the optimal design of induction heating coils.

• 한국연소학회지
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• 제12권3호
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• pp.24-32
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• 2007

A theoretical model was developed for rotary kiln and computational study was conducted to find the effect of feeding characteristics. One dimensional model with the variations of heating distribution, length of heating zone, excess air ratio and revolution was considered. The comparison of parallel-flow rotary kiln with that of counter-flow was conducted. For parallel-flow type, it is found that the variation of temperature of solid is not great for the zone that is following flame-heating zone. This zone is good to take the special treatment because thermal deviation is small and contacting time is enough for another treatment. Increase of excess air ratio have the effect of decreasing solid temperature. But this effect of decreasing solid temperature goes small for the great excess air ratio. The heating is efficient for the flame which has the maximum heating at the central region of the full length.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.278-283
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• 2003

Analysis has been carried out to investigate the temperature variation and the uniformity of the temperature distribution of the glass panel by infrared radiant heating. Halogen lamps are used to heat the panel and located near the top and bottom of the rectangular chamber. The thermal energy is transfered only by radiation and the radiation exchange occurs only on the solid surfaces and is considered by using the view factor. The results show that the uniformity of the temperature distribution of the panel is improved but the time for heating increases as the wall reflectivity is large. The temperature difference reaches a maximum in the early stage of the heating process and then decreases until it reaches the uniform steady-state value.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.243-248
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• 2001

The objective of this study is to investigate the thermal conductivity of cement mortar for apartment housing floor using expansive admixture, copper fiber, cower lathe, hollowed aluminum plate. According to test results, temperature at point (a) located above heating pipe does not show significant variation with age, and temperature at (b), which is located at the finishing surface above heating pipe, and temperature at (c), which is located at center surface between heating pipe has remarkable change. Temperature distribution sat (b) are in order for, structure containing copper fiber>plain structure>structure containing hollowed aluminum plate>structure containing expansive admixture. Temperature distribution, shows high tendency in order for, structure containing copper fiber>structure containing copper lathe>structure containing hollowed aluminum plate>plain structure>structure containing expansive admixture. (a) estimation of temperature distribution is determined with the variation of temperature between (b) point and (c) point during 60 minutes heating.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1178-1183
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• 2004

Temperature distribution and heating characteristic of the panel heater for infrared heating have been investigated. The temperature variation with time is firstly measured with the thermocouple to figure out the response time of the heater to the power input. The heater reaches faster to the steady state in comparison to the ceramic heater. The infrared thermal imaging system is utilized to investigate the temperature distribution over the heater surface. The measured thermal images show that the thermal boundary layer induced by the free convection near the heater surface affects the temperature distribution on the surface. The images also show the fairly good uniformity of the temperature distribution in the core region of the surface.