• 제목/요약/키워드: Electrical heating

검색결과 1,225건 처리시간 0.027초

필름 히터를 이용한 스마트 팜 난방 성능 설계에 관한 연구 (A Study on the Design of Smart Farm Heating Performance using a Film Heater)

  • 김웅
    • 소성∙가공
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    • 제32권3호
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    • pp.153-159
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    • 2023
  • This paper presents the optimal design of a heating system using radiant heating elements for application in smart farms. Smart farming, an advanced agricultural technology, is based on artificial intelligence and the internet of things and promotes crop production. Temperature and humidity regulation is critical in smart farms, and thus, a heating system is essential. Radiant heating elements are devices that generate heat using electrical energy. Among other applications, radiant heating elements are used for environmental control and heating in smart farm greenhouses. The performance of these elements is directly related to their electrical energy consumption. Therefore, achieving a balance between efficient electrical energy consumption and maximum heating performance in smart farms is crucial for the optimal design of radiant heating elements. In this study, the size, electrical energy supply, heat generation efficiency, and heating performance of radiant heating elements used in these heating systems were investigated. The effects of the size and electrical energy supply of radiant heating elements on the heating performance were experimentally analyzed. As the radiant heating element size increased, the heat generation efficiency improved, but the electrical energy consumption also increased. In addition, increasing the electrical energy supply improved both the heat generation efficiency and heating performance of the radiant heating elements. Based on these results, a method for determining the optimal size and electrical energy supply of radiant heating elements was proposed, and it reduced the electrical energy consumption while maintaining an appropriate heating performance in smart farms. These research findings are expected to contribute to energy conservation and performance improvement in smart farming.

Induction Heating PWM High Frequency Inverter using New Active Auxiliary Resonant Snubber

  • Mun, Sang-Pil;Kim, Chil-Ryong;Lee, Jong-Kurl;Kim, Hong-Sin;Jung, Sang-Hwa;Kwon, Soon-Kurl
    • 조명전기설비학회논문지
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    • 제22권3호
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    • pp.40-51
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    • 2008
  • This research presents a new active auxiliary resonant snubber with for induction heating PWM high frequency inverter solving the problem of induction heating PWM high frequency inverter circuit which is using widely in the practical application of an induction heating apparatus, the soft switching operation and power control are impossible when the lowest power supply in the active auxiliary resonant snubber with for induction heating PWM high frequency inverter. The inverter circuit which is attempted by the on-off operation of a switch has the effect of reducing the power loss due to soft switching and high frequency switching. This confirms that power regulation is possible on a continuous basis from 0.25[kW] to 2.84[kW] where the duty factor(D) changes from 0.08 to 0.3 under zero current switching which operates by an asymmetrical pulse width modulating control. The power conversion efficiency is 95[%]. Due to these results, the active auxiliary resonant snubber for an induction heating PWM high frequency inverter is considered effective as a source of induction heating.

전기 저항열을 이용한 유류 오염토 복원공정 적용을 위한 토양의 가열특성 연구 (Heating Characteristics of the Soils for the Application of Electrical Resistance Heating with Soil Vapor Extraction)

  • 윤여복;고석오;박기호;박민호
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제11권1호
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    • pp.45-53
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    • 2006
  • 본 연구에서는 토양의 전기가열 특성을 실험을 통해 규명함으로서, 전기저항열을 이용한 토양증기추출법을 실제 현장에 적용 시 토양가열 효율을 증가시키는 방안을 도출하기 위하여, 반응조를 이용한 토양 종류별 자체 특성에 따른 가열 특성과 외부에서의 전기적 특성의 조절을 통한 가열 특성을 살펴보았다 토양의 업자가 작을수록, 토양 내 이 온이 풍부할수록 전기가열 효율이 증가되었으며, 토양이 물로 포화된 경우에도 전기 가열 효율이 증가하였으나 공극률 이상으로 수분이 있는 경우는 오히려 효율이 떨어졌다. 전압이 증가할수록, 전극 사이가 짧아질수록, 유류 오염된 토양일수록 효율은 증가되었다 본 연구에서는 초기 전류와 전기전도도의 정량적 상관관계를 도출함으로써 직접적인 전기가열 실험 없이 전기전도도로 반응조 내 토양이 $100^{\circ}C$ 온도 상승의 가능성을 예측할 수 있게 됐다.

전도성 흑연을 포함하는 발열 필름의 열적 특성 (Thermal Characteristics of Heating Films Including Conductive Graphite)

  • 최규연;오원태
    • 한국전기전자재료학회논문지
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    • 제33권6호
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    • pp.500-504
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    • 2020
  • Heating films were prepared with composites of poly (methyl methacrylate) and conductive graphite. The as-prepared composite was deposited on a PET film and then fabricated using a bar coater to produce a film with uniform thickness. Copper electrodes were attached to both ends of the as-prepared film, and the heating characteristics of the film were analyzed while applying a DC voltage. The electrical conductivity and heating temperature of the heating films depended on the size, structure, content, and the dispersion characteristics of the graphite in the composite. The thermal energy was adjusted by controlling the electrical energy, based on the Joule heating theory. The electrical resistance of the film was altered in proportion to Ohm's law, and the heating temperature was changed according to the structure of the film (interelectrode spacing or electrode length) and the conductive graphite content. When the content of conductive graphite in the film increases, the electrical resistance decreases, and the heating temperature increases; however, there is no significant change above a certain content (50%).

전류원 PWM 컨버터 / 인버터를 이용한 새로운 단조용 유도가열 전원장치의 설계 (Design of New Induction Heating Power Supply for Forging Applications Using Current-Source PWM Converter and Inverter)

  • 최승수;이창우;김인동
    • 전기학회논문지
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    • 제67권12호
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    • pp.1602-1610
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    • 2018
  • Induction heating can convert electrical energy to thermal energy with high conversion efficiency and quick heating. Currently, a current source rectifier/inverter-fed parallel resonant circuit is widely used as an induction heating power supply for forging applications. However, the conventional induction heating power supplies composed of phase-controlled rectifier and SCR inverter have low efficiency and low power factor at input side, and require additional starting circuitry. So this paper proposes new induction heating power supply topologies for forging applications which have high power factor, high efficiency, and large output power. It also suggests detailed design guideline.

Electrical Transport and Joule Heating of ZrB2 Network in SiC Matrix

  • Kim, Jung-Hun;Kim, Chang-Yeoul;Choi, Sung-Churl
    • 한국세라믹학회지
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    • 제55권5호
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    • pp.440-445
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    • 2018
  • To control the electrical properties of a SiC heating element, we sintered $SiC-ZrB_2$composites by using the spark plasma sintering method. The addition of $ZrB_2$ particles with lower electrical conductivity to the SiC matrices with comparatively higher electrical resistivity lowers the electrical resistivities of the composite material. The $ZrB_2$ particles aggregate to form large particles and 3-1, 3-2, and 3-3 networks, i.e., conduction paths. In our study, about $1-{\mu}m$-sized $ZrB_2$ powders start to form the conduction path at about 10 vol.% of addition, namely the threshold volume. The Joule heating experiment shows that 20 vol.% $ZrB_2$-added SiC heating element has outstanding heating efficiency.

분전반 내 차단기의 접속불량에 의한 이상발열에 관한 연구 (A Study on the Abnormal Heating of Circuit Breaker in Panel Board by Poor Connection)

  • 김향곤;김동우;최효상;최용성;최충석
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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    • pp.10-14
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    • 2008
  • In this paper, abnormal heating of circuit breaker in panel board by poor connection was studied. Firstly, calculation method of contact resistance shown in IEC 60943 was examined. Secondly, concerning abnormal heating of circuit breaker in panel board, field measurements were performed. Field measurements showed that locally abnormal heating by poor connection could be detected, therefore, in that case, immediate action was needed. Finally, experiments regarding abnormal heating between terminal of circuit breaker and electric wire were conducted. The results showed that abnormal heating above $180^{\circ}C$ was measured. Also, in the results of analysis of electrical waveforms according to load current, voltage drop occurred around poor connection, and the oxide was generated according to mechanical vibration. In order to prevent electrical disaster caused by poor connection, adequate torque should be applied to electrical connection, and periodic check-ups are needed.

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고효율 유도가열형 전기온풍기에 관한 연구 (A Study on the Electrical Fan Heater using High Efficiency Induction Heating)

  • 신대철;우형균
    • 조명전기설비학회논문지
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    • 제26권3호
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    • pp.24-30
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    • 2012
  • A proposed the electrical fan heater using induction heating is innovative system which applied IH(Induction Heating) magnetic induction heating generated from induction-heated metallic package and high-frequency power circuit technique for thermal converse technique. In this occurs not burning, so that the working environment and deterioration of products can be improved. The existing heater that low efficiency by heated resistance or using fossil fuel of coal, diesel, kerosene has problems about burden for high cost price. In this paper are compared efficiency the existing heaters and designed electrical fan heaters using 3[kW]-Class full-bridge resonant inverter. In addition, action analysis and application of system are discussed.

유연한 섬유상 발열체용 카본블랙 복합소재의 전기적 특성 (Electrical Properties of Carbon Black Composites for Flexible Fiber Heating Element)

  • 박지용;이종대
    • 한국응용과학기술학회지
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    • 제32권3호
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    • pp.405-411
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    • 2015
  • Carbon composites for flexible fiber heating element were examined to improve the electrical conductivity in this study. Carbon composites using carbon black, denka black, super-c, super-p with/without CNF or dispersant such as BCS03 and Sikament-nn were prepared. Carbon composite slurry was coated on plane film and yarns(cotton, polyester) and the performances of prepared heating materials were investigated by checking electrical surface resistance, adhesion strength. The plane heating element using carbon black under natural drying condition($25^{\circ}C$) had better physical properties such as surface resistance(185.3 Ohm/sq) and adhesion strength(above 90%) than those of other carbon composite heating elements. From these results, polyester heating element coated by carbon black showed better electrical line resistance(33.2 kOhm/cm) than cotton heating element. Then, it was found that polyester heating element coated by carbon black with CNF(3 wt%) and BCS03(1 wt%) appeared best properties(0.604 kOhm/cm).

첨가제 변화에 따른 $MoSi_2$ 고온발열체의 전기적 특성 (A Study on Electrical $MoSi_2$ High Temperature Heating Elements by Additives)

  • 이후인;한상옥;구경완
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1405-1407
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    • 2001
  • It was studied to prepare high temperature heating elements using molybdenum disilicide($MoSi_2$). Molybdenum disilicide is widely used as material for manufacturing high temperature heating elements. $MoSi_2$ heating elements could be used at 1700-1900$^{\circ}C$. However, it is relatively expensive, and its demand depends on import. $MoSi_2$ powders was mixed with 4-5wt% of montmorillonites type bentonite as plasticizer and a small amount of $Si_3N_4$, $ThO_2$, and B as additives to prepare specimen of heating elements. Then, it was extruded, dried, sintered and machined followed by heating test. Effects of sintering conditions and amount of additives were investigated, It was sintered effectively at 1,350$^{\circ}C$ for five hours. Electrical resistivity was decreased with increasing of sintering temperature and time, and related with apparent density of the specimens. It was linealy decreased with increasing of sintered density. The heating elements thus prepared was stable at 1700$^{\circ}C$ and the physical properties such as specific electrical resistivity, hardness, apparent density, thermal expansion coefficient, and bending strength were almost identical with those of commercial heating elements.

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