• Title/Summary/Keyword: Thermal heating

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An Effect of Heat Input on Thermal Storage for Horizontal Thermal Storage Tank with Heat pipe (열 파이프용 수평 축열조에서의 열 입력이 축열에 미치는 영향)

  • 최우석;박이동;김철주;황영규
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1995.05a
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    • pp.69-76
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    • 1995
  • The horizontal thermal storage tank with heat pipe which is suitable for the sensible heat storage system is able to store a hot water from the heat source such as heating pad efficiently and to supply a hot water to load rapidly. Therefore Arrangement of heating pad affects thermal flow and thermal storage efficiency. So, if effective arrangement is decided for condition of constant number of heating pad, the more rapid thermal flow effect and higher thermal storage efficiency is obtainable by active heat transfer. In this experiments, number of heating pad is ranged from three, five and nine, and when number of heating pad is constant, arrangement are two types of concentration-type and dispersion-type. As a result, for the case of concentration-type of heating pad, strong entrainment take place in horizontal thermal storage tank with heat pipe by active heat transfer and in the constant number of heating pad, the concentration-type has the higher efficiency with about 5∼6% than the dispersion-type. Therefore, when heating pad is equipted to horizontal thermal storage tank with heat pipe, concentration-type of heating pad is an efficient design in constant number. of heating pad.

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Fundamental Studies on the Thermal conductivity and Thermal Diffusivity of Rough rice (벼의 열전도계수와 열확산계수에 관한 기초연구)

  • 김만수;고학균
    • Journal of Biosystems Engineering
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    • v.4 no.2
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    • pp.53-63
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    • 1979
  • The knowlege of thermal properties of rough rice has become of greate importance to the analysis of heat and mass transfer phenomenon in rice drying and storage process. Some information is available on the thermal properties of rough rice in foreign countries but is not available for these properties in Korea. A fundamental study was made to determine the thermal conductivity and thermal diffusivity of rough rice with line source method and to select current and resistance suitable for these properties from investigating the effect of current and resistance of heating wire on the temperature rise. The result of this study may be summarized as follows ; 1. Even through the power per unit length of heating wires is about the same, the tendency of temperature rise showed a little difference among them , and the suitable range of it for thermal properties was found to be 3.56-5.37w/m. 2. the most desirable resistance and current of heating wire was 18.40 ohm/m, 0.44 amperes among three kinds of heating wires and currents, respectively. because it took 13 minutes or so for the heating wire to reach equilibrium temperature. 3. The thermal conductivity of rough rice was 0.120-0.130 w/m$ ^\circ C$. and thermal diffusivity of it was $5.8210 $\times10^{-8} -9.7529 $\times10^{-8} m^2 /s.$ 4.The thermal conductivity showed a little difference in variation with resistance of heating wire but the variation of current of heating wire at the same resistance did not affect the thermal conductivity , and the thermal diffusivity was not affected by the variation of resistance and current.

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A Study on the Characteristic of the Thermal Environment in the Heating System at a Living Room (난방방식에 따른 거실의 열환경 특성에 관한 연구)

  • 이무진;이승수;진영언
    • Journal of the Korean housing association
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    • v.12 no.1
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    • pp.85-92
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    • 2001
  • The purpose of this study is to investigate the characteristic of the thermal environment at a living room by the heating system(floor radiation heating, forced convection heating, combined heating, radiation convection heating), and to compares the change of the thermal environment after operating the heating with after the operation stopped based on the floor radiation heating. This study proposes the basic data for the design and the development of the thermal storage structure heating system which not only utilizes fully the characteristic of the comfortable thermal environment but also reduces the preheating period and be able to use the off-peak electricity.

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Experimental Study on Thermal Sensation Evaluation in Heating(part I: Emotion & Sensibility Image Evaluation by Indoor Temperature Change in Heating) (실내 난방시 온열쾌적성 평가에 관한 연구(part I;실내 난방시 실온변화에 따른 감성이미지 평가))

  • 한남규;금종수;김형철;김동규;김창연
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2003.05a
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    • pp.41-46
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    • 2003
  • In recently, Is inhabiting more than 70% indoors during a day in case of company employee and ordinary people which is looking at usual business. Therefore Thermal comfort of human body about indoor temperature and air flow acting very heftily. When intestine temperature is fallen for external low temperature and air flow in winter in case enter into heated room feel comfort by effect of temperature and feel comfort or discomfort by room heating condition gradually. Therefore it is important that grasp thermal comfort about temperature and air flow in heating to keep continuous comfort in indoor dwelling. Temperature and thermal comfort factor of emotion & sensitivity image exert fair effect since heating middle although thermal comfort change greatly effect on sensation about temperature at actuality heating early. Need much study yet in vantage point of emotion & sensitivity although much study were held about thermal and comfort sensibility and when heat in existing research until now. Therefore this study is targeting that evaluate thermal comfort through introduction of estimation method by emotion & sensibility image real and synthetic sensibility about thermal environment that is becoming winter heating.

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An Experimental Study on Difference of Thermal Sensation by Radiant Floor Heating (바닥난방 복사열에 의한 온열감 차이에 대한 실험연구)

  • Choi, Yoon-Jung;Shim, Hyun-Suk;Jeong, Youn-Hong
    • KIEAE Journal
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    • v.7 no.5
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    • pp.65-71
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    • 2007
  • The purpose of this study was to analyze the difference of thermal sensation by radiant floor heating as ecological design element. The experimental investigations were carried out in climate chamber, and subjects were 34 college-age females in good health. The experimental variable was radiant heat by floor heating, and experimental controlled conditions were indoor temperature, relative humidity, and air velocity in climate chamber and clothing value and activity of subjects. The results are as follows. (1) Indoor temperature($21{\pm}0.5^{\circ}C$) in climate chamber were maintained as controlling. Clothing values of the subjects were controlled as average 0.73 clo. In the floor heating-off, globe temperature was average $23.2^{\circ}C$(22.4~24.1), but in the floor heating-on, globe temperature was average $24.8^{\circ}C$(23.0~25.5). (2) In the floor heating-off, thermal sensation rating was average -1.03(slightly cool), in the floor heating-on, thermal sensation rating was average +1.03(slightly warm). (3) There were the differences of thermal sensation by radiant floor heating although indoor temperatures were maintained in an equal state. (4) The thermal sensation rating was tending upward according as the globe temperature was getting higher.

Aerodynamic Heating Test of Payload Fairing of KSLV-I (KSLV-I 페어링 공력 가열 시험)

  • Choi, Sang-Ho;Kim, Seong-Lyong;Kim, In-Sun
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.448-451
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    • 2008
  • KARI is developing a satellite launch vehicle that is called KSLV(Korea Space Launch Vehicle)-I. During the flight, launch vehicles are exposed to aerodynamic heating conditions while flying at high Mach numbers in the atmosphere. KARI constructed Aerodynamic Thermal Simulation Facility to simulate aerodynamic heating on the ground. ATSF is a facility that can simulate given temperature profile using about 4,000 halogen heaters on fairing model. Aerodynamic heating profile is got from result of thermal analysis using MINIVER, Thermal Desktop, and SINDA/FLUINT. Aerodynamic heating test of fairing of KSLV-I was done using engineering model of payload fairing and Aerodynamic Thermal Simulation Facility. It was found that thermal analytic results show good agreement with aerodynamic heating test results within 6$^{\circ}$C at fairing inner surface. Also it was confirmed that maximum temperature of fairing nose-cone inner surface during flight is lower than allowable temperature limit.

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A study on the thermal deformation characteristics of steel plates due to multi-line heating

  • Lee, Joo-Sung;Lee, Sang-Hoon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.1
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    • pp.48-59
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    • 2018
  • This paper is mainly concerned with developing the formulae of predicting thermal deformation of steel plate due to multi-line heating. By investigating the results of line heating test and numerical analysis, reasonable heat flux model has been defined. Formulae of predicting the transverse shrinkage and the angular distortion as the dominant thermal deformation types in plate forming by line heating have been derived based on the results of line heating test and numerical analysis with varying plate thickness, heating speed and distance between torches. This paper illustrates how the derived formulae are used in investigating the effect of multi-line heating upon the thermal deformation and how they can be used in defining the limit distance with that there is no interacted effect between torches. This paper ends with describing the extension of the present study.

An Effect of Heat Input on Thermal Storage for Horizontal Thermal Storage Tank with Heat pipe (열 파이프용 수평 축열조에서의 열 입력이 축열에 미치는 영향)

  • Pak, Ee-Tong;Jeong, Un-Chul
    • Solar Energy
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    • v.16 no.2
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    • pp.39-47
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    • 1996
  • The horizontal thermal storage tank with heat pipe which is suitable for the sensible heat storage system is able to store a hot water from the heat source such as heating pad efficiently and to supply a hot water to load rapidly. And arrangement of heating pad play an important role in thermal flow and thermal storage efficiency. In this experiments, number of heating pad is ranged from three, five and nine, and when there is no change on number of heating pad, arrangements are two types of concentration-type and dispersion-type. Strong entrainment take place in the case of concentration-type of heating pad, and rapid temperature rise(${\Delta}{\doteqdot}1.6{\sim}3.2^{\circ}C$) in the tank is obtainable on the concentration-type than dispersion-type. In the constant number of heating pad, the concentration-type has the higher efficiency with about $5{\sim}6%$ than the dispersion-type Therefore, concentration-type of heating pad is an efficient design in constant number of heating pad.

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Experimental study on Thermal Comfort of Electric Vehicle Occupants Using Local Proximity Heating Module (국부 근접 난방 모듈을 이용한 전기차 탑승자의 열쾌적성에 대한 실험적 연구)

  • Chae-Yeol Lee;Jong-Han Im;Jae-Wook Lee;Sang-Hee Park
    • Journal of the Korean Society of Industry Convergence
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    • v.27 no.3
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    • pp.655-663
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    • 2024
  • In order to meet the technological demand for indoor heating systems that ensure winter thermal comfort during the transition from internal combustion engines to electrification, a localized proximity heating module using surface heating elements was developed. The operational performance of heating module was tested in the low temperature chamber. The experiment conditions were varied by changing the chamber temperature (-10, 0℃), the air flow rate (6.2, 6.0, 4.2m3/h), the heater power (100, 80, 60, 40W). Thermal comfort model was confirmed using the CBE Thermal Comfort Tool applying ASHRAE standard 55. Under -10℃ condition, thermal comfort was satisfied at 23.4, 23.2℃ at power of 100W and air flow rate 6.0, 4.6m3/h. Under 0℃ condition, at power of 80W, air flow rate 6.2, 6.0m3/h, and at power of 60W, air flow rate 4.6m3/h showed results of 25.7, 26.1, 23.0℃, respectively, satisfying thermal comfort. This study analyzed the operating performance of the local proximity heating module in the low temperature chamber and applied thermal comfort model to prove applicability of local proximity heating module using surface heating elements and how to utilize the thermal comfort model.

Analyses of Energy Savings and Night Heating Performance of a Movable Thermal Insulation Shuttered Window (단열셔터를 적용한 구동창호의 에너지 절감 및 야간 난방성능 분석)

  • Lee, Jang-Man;Cho, Soo;Lim, Sang-Hoon;Song, Kyoo-Dong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.3
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    • pp.150-155
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    • 2013
  • Usually, a window tends to have a lower thermal performance, than that of an ordinary wall. This study analyzes the enhancement of thermal performance of a window, when a Thermal Insulation Shutter is installed. The analyses were conducted at the laboratory, and with a full-scale mockup house, and the U-factor and heating load were examined. The laboratory results show that the U-factor increased by approximately 28%, when a Thermal Insulation Shutter was installed. The temperature difference was about $5^{\circ}C$, and this shows that the Thermal Insulation Shutter enhances the thermal performance of the window, when installed. The mockup house was used to calculate the heating load; the heating load was reduced by more than 41%, and shows that the installation of a Thermal Insulation Shutter is an effective way to reduce heating energy consumption.