• Journal of the Korean Society of Safety
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• v.22 no.2 s.80
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• pp.36-40
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• 2007

This study presents on the analysis fire hazards of electric heater. In order to analyze fire hazards fire experiment is conducted. The fire experiment is conducted to simulate normal condition and abnormal condition. The abnormal condition experiment is simulated in which combustibles are placed near by electric heater. Vertical burning test(UL 94) is conducted for the fire retardant experiment. The results show that fire hazard is high in case of abnormal condition. And Material of electric heater has not fire retardant performance. In this paper, we suggest to add temperature fuse in electric heater for reducing fire hazard.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2001.02a
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• pp.76-79
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• 2001

The heater-triggered switching system for charging of a high temperature superconductor(HTS) is prepared by simulation and investigated its characteristic by experiment. heater-triggered switching system consists of two nickel-chrome alloy heater, an electromagnet and YBCO bulk HTS. There are three important parameters to generate the pumping-current in this system. The timing sequential control of two heters and electromagnet is an important factor to generate pumping-current in the YBCO bulk HTS. Thermal analysis of the switching part in YBCO bulk HTS according to the heater input current was carried out. Electromagnet of 0.6[T] and DC heater input current of 2.3[A] were optimally derived. In this experiment, the maximum pumping current is reaches about 12[A].

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.253-256
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• 2006

Most heater being used in vehicles has been used to a cabin heating by being supplied from a heat loss of the engine coolant for heat source efficiency. Recently, the heat loss is reduced by high efficiency in the engine. It becomes to require the combustion heater that directly bums the heater used in vehicles to provide heat source of the heater. The purpose of this study is to research a burner which will applicate combustion heater by the numerical analysis. There are the 5 different types of burners, which is designed by differently each design of the swirler. N-DODECANE by used the burner fuel is performed by numerical analysis in every 5 burner. The burner's efficiency testing is evaluated on the basis of the Exhaust gas temperature.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.156-161
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• 2004

The application of solar energy, in the field of alternative energy, was on the increase tendency. In the case of advanced nations, through continuous R&D, solar hot water heater with high efficiency has been used for the house and the industrial process on business, advanced nations were reached up the experimental stage of solar generation system. But, the actual circumstance of the domestic has been not accomplished the popularization of solar hot water heater and the settlement of it which is the fundamental stage of the solar energy usage. This trouble, the domestic was flooded with small enterprise for producing solar hot water heater, was caused by the popularization and the production without verification of performance. To supply the monitoring program for evaluating solar hot water heater, this research was purpose to improve the technical development of the enterprise for producing solar-heat hot-water-boiler and served as an aid for the enlargement and the popularization on solar energy.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.320-320
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• 2000

In this paper, a temperature controller of a test plate for semiconductor is developed using LQG/LTR methodology. The liquid is heated or cooled in a tank by a heater of a cooler. The controller controls the flow of heated or cooled liquid in the plate by controling an electronic valve. The developed controller is applied to the plate designed for function test of a semiconductor under high or low temperature environment. As a result, control using the heater and the cooler together shows better control performance than using the heater or the cooler separately.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.8
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• pp.1047-1054
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• 2018

This paper proposed the strategies for controlling both the heater temperature and the output voltage of a single-phase inverter for the heat treatment. The single-phase inverter system for the heat treatment controls the heater temperature to its reference one, and also it limits the inverter output voltage to 60 V for safety. The stability may be deteriorated due to the large time constant difference between the heater temperature and inverter output voltage. In order to ensure the stability, a hysteresis on/off control approach for the heater temperature control is adapted, and both the open-loop and the closed-loop control strategies of the output voltage are suggested. The performances for the proposed strategies are demonstrated with the experiments.

• Journal of Applied Reliability
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• v.6 no.1
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• pp.93-103
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• 2006

Basic function of calorifier system is to supply warm water to the vessel. The heater used in the calorifier system plays a very important role in its reliability. The failure mechanism of heater are compared with accelerated life test. The main cause of failed heater is pitting corrosion occurred between the surface of heater and spacer. To prevent the corrosion failure from heater, material of spacer replaces metal(SUS 304) with polymer (Acryl). The life of redesigned heater can guarantee 2.47years of B10 life under the worst condition.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.21 no.4
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• pp.225-244
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• 2017

The natural convective nanofluid flow and heat transfer inside a square enclosure with a center heater in the presence of magnetic field has been studied numerically. The vertical walls of the enclosure are cold and the top wall is adiabatic while the bottom wall is considered with constant heat source. The governing differential equations are solved by using a finite volume method based on SIMPLE algorithm. The parametric study is performed to analyze the effect of different lengths of center heater, Hartmann numbers and Rayleigh numbers. The heater effectiveness and temperature distribution are examined. The effect of all pertinent parameters on streamlines, isotherms, velocity profiles and average Nusselt numbers are presented. It is found that heat transfer increases with the increase of heater length, whereas it decreases with the increase of magnetic field effect. Furthermore, it is found that the value of Nusselt number depends strongly upon the Hartmann number for the increasing values of Rayleigh number.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3597-3611
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• 2021

The present paper studies the thermal-hydraulic behaviour of the rectangular supercritical natural circulation loop (SCNCL) using numerical model of one dimensional. Then the results of this model is confirmed with experimental and benchmark results. Variations with several geometric parameters like loop diameter, riser length, and heater length and operating conditions like heater inlet enthalpy, pressure, friction factor, and inlet and exit loss coefficient on steady-state performance are investigated for various orientations like HHHC, HHVC, VHVC and VHHC of the heater and cooler. The chances of existing static instability (Ledinegg excursion) has been investigated, which reveals that it can arise only in a low inlet enthalpy condition, far from the suggested various orientations of heater and cooler.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.178-183
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• 2012

To simulate space thermal environment in thermal vacuum test, direct or in-direct heater has been applied on the radiator. Both of them, direct heater attached on the radiator and indirect heater with a distance from the radiator, simulate the heat fluxes from the Sun radiation, the Earth IR and Albedo. They also supply the heat fluxes to the radiator of spacecraft to achieve the target temperature according to thermal test conditions. In general, indirect heater is used when the heater is not allowed to attach on the radiator directly due to constraints of coating property or contamination. For in-direct heater design, it is needed to estimate the heat power to make the extreme test conditions and minimize the interference with heat exchange of radiator and shroud. In this study, optimized thermal design of in-direct heater is proposed and investigated by commercial S/W SINDA. The effective values of design factors are also derived.