• 한국세라믹학회지
• /
• 제32권7호
• /
• pp.817-824
• /
• 1995

TiB2 was simultaneously synthesized and densified with concurrent self-propagating high-temperature synthesis and direct contact-heating by electrcial power input and pressure. Density of TiB2 synthesized by self-propagating high-temperature synthesis and consolidated simultaneously by direct contact-heating and pressure was maximum 80% of the theoretical density (4.52g/㎤). Temperature profile was analyzed by solving heat balance equation with numerical method (FTCS method). The temperature of the sample was sufficiently raised to that temperature sufficient to be densified. It was ascertained that the density of the SHS synthesized TiB2 is exponentially proportinal to the input thermal energy per mass.

• 조명전기설비학회논문지
• /
• 제24권1호
• /
• pp.117-123
• /
• 2010

제안한 유도가열 시스템은 증류탑 장치에 사용되는 특수적층 규칙충진체에 의한 열 교환기술과 IH(Induction-Heating)전자유도가열용의 특수한 고주파 전력회로 기술을 응용한 차세대 가열방식이다. 본 전자유도 유체가열기술은 IGBT대응의 고주파 인버터를 사용하여 상용교류로부터 수[kHz]의 고주파 교류를 발생시킬 수 있다. 공진형 고주파 인버터를 사용함으로 고성능, 고효율의 시스템화가 가능하다. 본 논문에서는 주파수 범위가 20[kHz]에서 44[kHz]인 고주파 공진형 인버터을 이용하여 증기를 발생시키는 유도가열시스템에 대해 제안한 온도제어에 대하여 기술하고자 한다.

• 공업화학
• /
• 제18권4호
• /
• pp.344-349
• /
• 2007

마이크로파 가열(microwave heating)에 의하여 제올라이트 NaY를 합성하였으며, 그 결과를 기존의 가열 방법(conventional heating)에 의하여 합성한 결과와 비교하였다. 같은 승온 속도를 사용하였을 때는 마이크로파에 의하여 가열하였을 때가 기존의 가열 방법에 비하여 NaY 결정 생성의 유도 기간(induction period)이 감소하였으며 결정의 생성 속도가 증가하였다. 또한 마이크로파의 사용 여부와 관계없이 승온 속도가 빠를 때도 유도 기간이 감소하고 결정 생성 속도가 증가하였다. 빠른 승온 속도에서 합성하였을 때 최종 결정의 크기가 크며, 이는 마이크로파의 사용에 의하여 더욱 증가하였다. 빠른 승온 속도에서는 반응 시간이 짧아져서 NaY의 합성에 소모되는 에너지 소모량은 감소하였다. 본 연구의 조건에서는 에틸렌글리 콜조(ethylene glycol bath)를 사용한 기존 가열 방법에서의 에너지 소모량이 마이크로파 가열보다 적게 나타났는데, 이는 마이크로파 에너지를 사용하는 것이 항상 효율적인 것만은 아니라는 것을 말해준다. 그러나 승온 속도를 적절히 조절하면 마이크로파 가열에 의해서 에너지 면에서 보다 효율적으로 NaY를 합성할 수 있다는 것을 알 수 있었다

• Elastomers and Composites
• /
• 제51권4호
• /
• pp.280-285
• /
• 2016

The purpose of this study is to get optimum design and operation conditions of the heating rubber roller for laminating process. The cause of performance degradation of heating rubber roller is delamination of rubber on metal tube, rubber aging due to high temperature. We measured the material properties of thermal expansion, thermal conductivity, specific heat and density and analyzed thermal distributions of rubber layer using finite element method. As a result of heat/flow analysis, the density distribution of heating coil must shorten the stabilization time by reducing the temperature deviation on the length direction at the temperature rising section after increasing the density of the area contacting with the laminate film at the center part which is an opposite of the current composition while enabling to maintain the temperature of heater to be consistent while maintaining the temperature deviation to be low when heat loss is created. Finally, we determined optimum heating method of heating rubber roller.

• 한국정밀공학회지
• /
• 제22권1호
• /
• pp.97-102
• /
• 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
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.465-468
• /
• 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.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
• /
• pp.111-114
• /
• 2011

Waterprooping Method with sheet need to study technology and multilateral verification considering the arctic conditions as low temperature and humidity, which is the result only considered of material aspects without environmental condition in construction But there are no measures up until now. To solve this problem by using high frequency induction heating method developed waterproof sheets, cold (5 ℃ or less) can be applied in a more stable environment, water-resistant materials and construction methods were studied for development. The results of the test showed that high frequency induction heating method is effective for usability in low temperature condition and securement of proper quality than existing Waterprooping Method with sheet need.

• 한국지열·수열에너지학회논문집
• /
• 제12권1호
• /
• pp.17-22
• /
• 2016

It is very important to obtain a out-of season production in horticultural greenhouses corresponding with higher crop prices. A ground source heat pump system has been highly spotlighed as an energy efficient heating system for the greenhouse. This paper investigated the operating cost of the ground source heat pump system with the variation of generating temperature and designing methods for heating system of the greenhouse. Even though the COP of the ground source heat pump system decreased with an increment of generating temperature in heating mode, the operating cost could be reduced. By adopting the high temperature heat pump system and heat storage tank, it could be achieved to save energy and reduce the operating time of auxiliary oil heating system for producing good plant-growth in the greenhouse.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제48권6호
• /
• pp.436-441
• /
• 1999

Joule heating effect in EM(Electromigration) test were performed on a bend test structure. EM test is done under high current densities(1.0-2.5MA/cm2), which leads to joule heating. Since joule heating is added to the controlled oven(stress) temperature, themetal line temperature is higher than the stress temperature. The increase in the stress temperature due to joule heating is important because EM phenomena and metal line failure are related to the stress temperature. In this paper, metal line was stressed with a current density of 1.0 MA/$cm^2$, 1.5MA/$cm^2$, 2.0MA/$cm^2$, 2.5MA/$cm^2$, for 1200 sec and temperature increase due to joule heating was less than $10^{\circ}C$. Also it took 30 minutes for the metal line to equalized with oven temperature. Recommendations are given for the EM test to determine the initial resistance of EM test structure under stress temperature and current density.

• 한국태양에너지학회 논문집
• /
• 제30권4호
• /
• pp.49-54
• /
• 2010

Most energy using in building part is mainly consumed for heating and cooling to meet occupancy's comfort temperature. Generally, heating energy consumption show high value than cooling energy in Korea because of high temperature difference in winter season as compared with summer in apartment building. The efforts to develope mechanical performance have been studied to reduce energy consumption in building energy field until now. However, the energy consumption in building is impacted by not only system performance but also PMV particularly at temperature and Clo value. This means that energy consumption can be changed by occupancy's comfort setting temperature in apartment building. This study investigated the passibility of overheating in apartment building by occupant' slow Clo and its setting temperature from preceding research and then the heating energy consumption by setting temperature was calculated with ESP-r. The effects of heating energy and $CO_2$ reduction are also evaluated quantitatively with Clo value. The results showed that keeping ISO-7730 standards can reduce heating energy up to 21% in compared with option 2; also, wearing underclothes with ISO-7730 standard can considerably reduce heating energy consumption up to 50%. As compared with option 2, the reduction of $CO_2$ emission for option 3 showed 0.63TCO2 of kerosene, 0.49TCO2 of LNG and 1.09TCO2 of electricity. The option 4 can be reduced by 1.48TCO2 of kerosene, 1.16TCO2 of LNG and 2.57TCO2 of electricity respectively.