• Journal of Welding and Joining
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• v.19 no.5
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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.

• Nuclear Engineering and Technology
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• v.50 no.7
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• pp.1079-1087
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• 2018

There are many parameters that affect the natural circulation flow, such as height difference, heating power size, pipe diameter, system pressure and inlet temperature and so on. In general analysis the heating power is often regarded as a uniform distribution. The ANSYS-CFX numerical analysis software was used to analyze the flow heat transfer of supercritical water under different heating power distribution conditions. The distribution types of uniform, power increasing, power decreasing and sine function are investigated. Through the analysis, it can be concluded that different power distribution has a great influence on the flow of natural circulation if the total power of heating is constant. It was found that the peak flow of supercritical water natural circulation is maximal when the distribution of heating power is monotonically decreasing, minimal when it is monotonically increasing, and moderate at uniform or the sine type of heating. The simulation results further reveal the supercritical water under different heat transfer conditions on its flow characteristics. It can provide certain theory reference and system design for passive residual heat removal system about supercritical water.

• Journal of the Korean housing association
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• v.1 no.1
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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 the Korean Wood Science and Technology
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• v.32 no.4
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• pp.18-26
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• 2004

Timbers of 14 by 14 cm, 2.4 m long, were dried in a vacuum kiln to investigate vacuum drying characteristics using three types of heating methods, conduction heating with hot plate, the radio frequency (RF) heating and the combination of both (hybrid heating). Average drying rate is the highest for the hybrid heating and the lowest for the RF heating. Average specific energy is the highest for the RF heating and the lowest for conduction heating. Transverse moisture content distribution of dried timber revealed the convex profile for both conduction and the hybrid heating and moisture content increased from one face to the opposite face for the RF heating. Moisture content distribution along the length of timber increased from the end to the middle of timber length for conduction and the hybrid heating and decreased from the end to the middle of timber length for the RF heating. End- and surface checks for conduction heating were severer than the other heating methods. No internal check occurred in any heating methods. Drying characteristics of conduction heating showed in-between trend of the RF and the hybrid heating.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2771-2788
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• 2020

Experiments are conducted to study bubble flow behavior during the instability of subcooled boiling under uniform and non-uniform transverse heating. The non-uniform heat distribution introduces nonuniform bubble generation and condensation rates on the heated surface, which is different from the uniform heating. These bubble generation and condensation characteristics introduce a non-uniform local pressure distribution in the transverse direction, which creates an extra non-uniform pressure on the flowing bubbles. Therefore, different bubble flow behavior can be observed between uniform and non-uniform heating conditions. In the uniform heating, bubble velocity fluctuations are low, and the bubbles travel straight along the axial direction. In the non-uniform heating, more fluctuation in the bubble velocity occurs at low mass flow rate and high subcooled inlet temperatures, and reverse flow is observed. Additionally, the bubbles show a zigzag trajectory when they pass through the channel, which indicates the existence of cross flow in the transverse direction.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.5
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• pp.617-624
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• 2010

Line heating is a manufacture method, which was widely used to machining a curved surface in the ship construction. The qualities using by line heating are very difference compare to the proficiency level of the engineer. So it's mainly depend on the automation equipment instead of the proficiency level engineer. In this study, it would be investigate the temperature distribution of the heating plate, which was used by the automation equipment according to line heating. The main factors are the moving velocity of the heating source, strength and the heating method separately, in temperature distribution while line heating. In this paper, it was investigated the temperature change with the vary of each three variables. The numerical result showed that peak temperature decrease if the moving velocity of the heating source increased. It can also calculate the change quantitatively that the peak temperature and temperature distribution changed linearly with the vary of the heating source.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.3
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• pp.698-701
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• 2017

The district heating system supports currently 1.3 million of houses in South Korea, and it is composed of two main parts: provision and distribution. For the provision part, Korea District Heating Corporation supervises the system with proper devices and experts, whereas for the distribution parts, there is no main supervision system and it depends highly on experts although it is very difficult to find the proper experts. In this paper, we consider IoT based remote management system for district heating distribution to properly supervise heating distribution by experts and/or programs remotely.

• Journal of the Korean Society of Combustion
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• v.12 no.3
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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.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.1
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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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.