• Tribology and Lubricants
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• 제33권6호
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• pp.296-302
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• 2017

Ball milling of elemental powders in advance and using an induction heating system for intermetallic coatings are known to enhance the reactivity of combustion synthesis. In this work, the effects of simultaneously applying these two incentive methods on the properties of intermetallic coatings are studied. Ni-Al powder compacts ball-milled with three different ball-to-powder weight ratio mixtures are synthesized and coated on mild steel by combustion synthesis in an induction heating system. Consequently, similar to an electrical heating system, the positive effects of ball milling on the combustion synthesis are confirmed in the induction heating system. The enhancement in synthetic reactivity achieved by applying the two incentive methods at the same time is greater than that by applying each incentive method separately. In particular, the enhancement is remarkable at low reaction temperature. However, there are limitations to improving the reactivity by simultaneously applying the two incentive methods to the combustion synthesis, unlike the reaction temperature. The microstructure and hardness of the coating layer are both influenced by the ball-charging ratio employed in the ball-milling process.

• 한국환경보건학회지
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• 제20권3호
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• pp.13-18
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• 1994

Information on the heating values of municipal solid wastes is very important in evaluating the feasibility of incineration and RDF (Refuse Derived Fuel) manufacture. This paper describes the forecasting methods about the lower heating values of municipal solid wastes. The lower heating values are forecast by the heating values of physical components. The municipal solid wastes consist of paper, food wastes, textiles, plastics, wood and rubber (contained leather). These are the physical components of municipal solid wastes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.445-448
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• 2004

Radio frequency and microwave dielectric heating are well-known electroheating methods, used in industrial applications where non electrically conducting materials are to be heated, dried or otherwise processed. The major reason for considering this technique for any process is based on its unique ability to transfer heat into the volume of an electrically non conducting material such as insulator directly, rather than, via a surface. Conventional heating must first bring heat to the product surface and there after it depends on the physical characteristics and condition of the material as to how effectively this heat is transmitted into the mass. The product would suffer surface damage before the main body is adequately processed. Dielectric heating is applied to enhance conventional heating methods and to drastically shorten the required processing duration. Although the use of dielectric heating has been a well proven technique for several years in some industries, its application in the preheating of FRP has been limited by the insufficient experience. In this paper a method is described for uniform radio frequency heating of preheating of FRP.

• 설비공학논문집
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• 제13권12호
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• pp.1297-1305
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• 2001

In this study, existing control methods that are suggested or applied until now are classified by control parameters, and stability of in the room and floor surface temperatures of each control method is compared through experiments. Then, the control performance of these control methods are analyzed to evaluate the applicability to Korean apartment housing. From the result of the applicability analysis, the outdoor reset with on/off PWM control is found to be desirable for district heating systems and flux modulation is found to be applicable for decentralized heating systems. In the case of independent control systems for each room, on/off PWM control is desirable.

• 한국산학기술학회논문지
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• 제7권4호
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• pp.738-742
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• 2006

본 연구에서는 전열을 이용한 금형가열 장치를 설계 및 제작하였다. 서로 다른 가열원을 가진 세 가지 방법으로 제작을 하여 시간에 따른 온도 프로파일을 조사함으로써 그 성능을 평가하였고, 이를 이용하여 사출성형품을 제조하여 수축률, 밀도, 표면 거칠기, Weld line등을 측정하여 실용적인 적용 가능성을 조사 하였다. 가열시간($130^{\circ}C$ 도달시간 14초) 및 사이틀 타임(55초)은 실용화가 가능한 수준으로 나타났다. 일반 사출성형방식으로 성형한 제품과 비교했을 때 수축률은 전열을 이용한 가열방식으로 사출한 성형품이 5.1% 감소하였고, 밀도는 2.66% 증가하였다. 표면 거칠기는 3배 이상 향상 되었고, 일반 사출에서 나타나던 Weld line은 전열가열방식에서는 나타나지 않았다.

• 한국도로학회논문집
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• 제18권2호
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• pp.29-36
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• 2016

PURPOSES: The objective of this study is to determine the milling temperature that minimizes the binder-induced damage to the aggregate; this is achieved by evaluating the temperature dependence of the viscosity of the asphalt binder, with the aim of developing an effective heating process for warm in-place recycling. METHODS : The validity of the indoor test was confirmed by conducting an internal heating test based on the on-site heating test. In addition, the adhesive power of the binder was measured at various temperatures ($30^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, $60^{\circ}C$, $70^{\circ}C$) via three types of measuring methods. RESULTS: The surface temperature spectrum of field test was slight different with that of laboratory test. But, the spectra of inner temperature between the field and the laboratory was almost similar. Also, the adhesion of the asphalt binder was measured from $30^{\circ}C$ to $70^{\circ}C$. The adhesion of the binder was significantly decreased from $60^{\circ}C$. Contrary to other temperature, the adhesion was slightly changed from $60^{\circ}C$ to $70^{\circ}C$. Also the inner temperature between two different heating methods was shown similar temperature spectra. CONCLUSIONS: The pavement heating temperature spectrum of hot in place recycling method was simulated by a laboratory test. Based on this study, the optimum temperature was $60^{\circ}C{\sim}70^{\circ}C$ for reducing aggregate damage during milling process. The susceptibility heating method developed in this study can be maintained the optimum inner temperature range.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1008-1013
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• 2009

The theoretical simulation to predict the variation of supplying heat according to control methods of DHS(District Heating System) have been done by TRNSYS(A Transient System Simulation Program) 16. The physical system for DHS consists of primary and secondary supplying heating loop which is divided by based on heat exchanger for heating demand of building. The simulation results showed that control of secondary supplying heat had influenced more than primary supplying heat control to total energy consumption of DHS. And the outside temperature reset control of primary supplying heating loop could be reduced until about 4% overheating of each zone.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.161-166
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• 2007

Various thermostatic valves have been used widely in Korea for conservation of heating energy and enhancement of thermal comfort in residential buildings. But heating control performances of thermostatic valves extensively vary with the design and operational conditions of the heating system, climate condition and others. An experimental method was carried out in this study to analyze heating control characteristics by temperature sensing methods of thermostatic valves for various parameters, such as supply temperatures and flow rate of hot water, the position of room thermostats and outdoor air temperatures. As a result, the heat flow rate per day of S-Valve($34^{\circ}C$-Type) of water temperature sensing method was liked that of C-Valve of indoor air temperature sensing method with stage 3.3 of room thermostat in case supply temperature of hot water was $45^{\circ}C$, flow rate was 1.3 L/min and outdoor air temperature was $7.8^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• 제28권4호
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• pp.83-93
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• 2000

This study was carried out to improve the physico-mechanical properties of board products by applying the technique of high frequency heating, and find out the optimum conditions of high frequency heating, compared with the technique of hot platen heating. The possibility of isocyanate resin application to board production was also considered to solve the problem of free formaldehyde emission from urea resin which is generally used in wood industry. For this study, 30 mm thick MDP (medium density fiberboard) with isocyanate resin were manufactured by the techniques of hot platen heating, high frequency heating and the combination techniques of both heating methods, and compared in several point of views.

• Carbon letters
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• 제15권1호
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• pp.15-24
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• 2014

As a part of the electromagnetic spectrum, microwaves heat materials fast and efficiently via direct energy transfer, while conventional heating methods rely on conduction and convection. To date, the use of microwave heating in the research of carbon-based materials has been mainly limited to liquid solutions. However, more rapid and efficient heating is possible in electron-rich solid materials, because the target materials absorb the energy of microwaves effectively and exclusively. Carbon-based solid materials are suitable for microwave-heating due to the delocalized pi electrons from sp2-hybridized carbon networks. In this perspective review, research on the microwave heating of carbon-based solid materials is extensively investigated. This review includes basic theories of microwave heating, and applications in carbon nanotubes, graphite and other carbon-based materials. Finally, priority issues are discussed for the advanced use of microwave heating, which have been poorly understood so far: heating mechanism, temperature control, and penetration depth.