• Title/Summary/Keyword: external heat method

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A Characteristic Heating-Energy Expend of Insulation Block System for Korea Type Passive House (한국형 패시브하우스를 위한 단열블럭시스템의 난방에너지소비 특성)

  • Kang, Jae-Sik;Choi, Gyoung-Seok;Yang, Kwan-Seop;Lee, Seung-Eon
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.603-607
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    • 2009
  • About a Structure is performance external insulation is fundamantal performance for enrgy-saving. these day, most of residential structures have constructed by internal insulation method structure. The method structure internal insulation have construction and economical efficiency, but on the other hand, be generated heat loss by heat bridge especially, be generated loss heat-energy logical consequence in structure ondol. The external insulation structure method has a mert able to minimum to loss heat about heat-bridge. But the external insulation technique is unsatisfactory statues within the know-how and method of construction and materials compared with developed countries. The recently, the requirement of market related to the external insulation technique is resulted by the energy efficiency system, but it can lead to the lack of alternative technique In study on the korea type passive house building design for insulation block method of wall system has to experimental characteristic heat-energy of practice building. In result field-experimental, the heat-bridge appeared to characteristic spent heat-energy of blow 2L class and have a suffience performance it.

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The Heat Transfer Analysis of 1.2[kW] BLDC Motor on the Condition of the External Flow (외부 유동을 고려한 1.2[kW] BLDC 모터의 열 전달 해석)

  • Hwang, Ha-Young;Chung, Tai-Uk;Lee, Dong-Yeon;Hwang, Pyung;Shim, Jae-Sool
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.2
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    • pp.27-33
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    • 2012
  • In this paper, we researched the heat transfer analysis of 1.2[kW] BLDC motor on the condition of the external flow. The BLDC motor is fallen under influence of some heat generated by rotationg motor speed and it changes the life and confidence of motor. The heat makes to reduce the life of insulation and the magnetization. So motor can't make own performance. Therefore we calculated the losses about number of revolutions of motor. And then, we analyzed the heat transfer of BLDC motor by using the results when a fan attached to motor makes the external flow or not. The results showed that the temperature of motor increased constant values irrespective of external air temperature. The temperature of motor decreased very lower values than prior researches when the fan makes the external flow. In this method we can analyze the performance, losses and heat transfer of motor applied in the many industries.

NUMERICAL ANALYSIS FOR UNSTEADY THERMAL STRATIFIED FLOW WITH HEAT TRACING IN A HORIZONTAL CIRCULAR CYLINDER

  • Jeong, Ill-Seok;Song, Woo-Young;Park, Man-Heung
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.05a
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    • pp.304-309
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    • 1997
  • A method to mitigate the thermal stratification flow of a horizontal pipe line is proposed by heating external bottom of the pipe with electrical heat tracing. Unsteady two dimensional model has been used to numerically investigate an effect of the external Denting to the thermally stratified flow. The dimensionless governing equations are solved by using the control volume formulation and SIMPLE algorithm. Temperature distribution, streamline profile and Nusselt numbers of fluids and pipe walls with time are analyzed in case of externally heating condition. no numerical result of this study shows that the maximum dimensionless temperature difference between the hot and the cold sections of pipe inner wall is 0.424 at dimensionless time 1,500 ann the thermal stratification phenomena is disappeared at about dimensionless time 9,000. This result means that external heat tracing can mitigate the thermal stratification phenomena by lessening $\Delta$ $T_{ma}$ about 0.1 and shortening the dimensionless time about 132 in comparison with no external heat tracing.rnal heat tracing.

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Analysis of the Energy Saving Effect for the External Insulation Construction by Building Load Calculation Method (건물 부하계산 프로그램을 이용한 외단열 시공의 에너지 절감 효과 분석)

  • Park, Jaejoong;Myeong, Jemin;Song, Doosam
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.3
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    • pp.97-104
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    • 2017
  • Reinforcement of insulation in apartment buildings reduces the heating and cooling energy consumption by lowering the heat transfer in the building envelope. There are differences between internal and external insulation methods in heat transmission properties. However, some building load calculation programs cannot analysis the differences between the two. This is because these programs do no account for the timelag or thermal storage effect of the wall according to the location of insulation. In this study, the heat transmission characteristics of internal and external insulation were analyzed by EnergyPlus, and heating and cooling energy demand was compared. The results showed that external insulation system had lower heating and cooling loads than internal insulation system. Also the heat transfer rate of external insulation is steadier than internal insulation. About 13.6% of heating and cooling energy demand decreased when the outdoor wall was finished with external insulation compared to the demand with internal insulation.

Microwave Hyperthermic Lipolysis Using External RF Antenna

  • Hwang, Joo-Sung;Woo, Tae-Hee;Park, Sang-Bok;Cheon, Chang-Yul
    • Journal of Electrical Engineering and Technology
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    • v.7 no.5
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    • pp.759-764
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    • 2012
  • In this paper, we propose a microwave hyperthermic lipolysis method to reduce subcutaneous fat without skin burn using external RF antenna. Since skin is closer to the antenna and has higher conductivity compared to the fat beneath, the temperature of the skin rises higher than that of the fat when the external antenna illuminates EM energy into a body, which may cause skin burn. In order to avoid the damages on skin, a skin cooling system is employed to the external antenna. The operating frequency is set at 5.8 GHz which is one of the ISM bands, to concentrate EM power efficiently on fat and not to heat up the muscle behind the fat. The operation time and RF power level has been determined based on experimental results with pork. The feasibility of the proposed method was shown by applying the method to the rat.

Study on the Fire Suppression by Heat Transfer of Thermal Insulation Materials (건축물 외단열재의 열전달평가를 통한 화재 억제 방안 연구)

  • Ryu, Hwa Sung;Shin, Sang Hun;Song, sung young;Kim, Deuck Mo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.277-278
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    • 2018
  • Improvement of insulation performance of buildings is a major part. Adiabatic method The adiabatic method minimizes the heat loss of the building. External insulation uses insulation to prevent fire. Ambient air hazards are less prone to fire. When a fire occurs, a phenolic pattern is formed and bond strength with the wall increases. EPS insulation and phenol foam were used to compare external heat transfer and external heat transfer. The heat transfer properties of phenolic foam and styrofoam were evaluated as follows. In the mortar and styrofoam structure, the problem of styrofoam reaching the burning point occurred before the collapse of the mortar, and the phenol foam had a problem in that when the direct fire was continued on the phenol foam. The characteristics of continuous infiltration appeared. In the case of mortar and phenol foam + styrofoam, the heat penetrated into the interior due to the shrinkage due to the shrinkage of the carbon screen on the phenol foam. However, when reinforced with glass mesh on the outer surface, And to reduce infiltration.

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Laminar Convective Heat Transfer from a Horizontal Flat Plate of Phase Change Material Slurry Flow

  • Kim Myoung-Jun
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.7
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    • pp.779-784
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    • 2005
  • This paper presents the theory of similarity transformations applied to the momentum and energy equations for laminar, forced, external boundary layer flow over a horizontal flat plate which leads to a set of non-linear, ordinary differential equations of phase change material slurry(PCM Slurry). The momentum and energy equation set numerically to obtain the non-dimensional velocity and temperature profiles in a laminar boundary layer are solved. The heat transfer characteristics of PCM slurry was numerically investigated with similar method. It is clarified that the similar solution method of Newtonian fluid can be used reasonably this type of PCM slurry which has low concentration. The data of local wall heat flux and convective heat transfer coefficient of PCM slurry are higher than those of water more than 150$\~$200$\%$, approximately.

A Study on the Stress Distribution of Steel Water Pipes(II) - Characteristics of Stress Distribution by External Forces and PWHT - (상수도용 도복장간관의 용접 및 외부하중에 의한 응력 특성에 관한 연구(II) - 복합외부하중 및 후열처리에 따른 용접부의 응력분포 특성 -)

  • 윤석환;이승기;나석주;고명환
    • Journal of Welding and Joining
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    • v.19 no.3
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    • pp.292-297
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    • 2001
  • One of the major characteristics that affects the life of welded steel water pipes is the stress distribution caused by welding and external forces. Some studios have bean carried out on the residual stress of steel water pipes. But the results on the stress distributions by welding and complex external forces are rare, because real water pipes operate under the ground and many kinds of external forces act simultaneously on the joints. To understand the complex stress distributions of welded joints, therefore predictions by numerical or analytic methods are required. In this study, temperature and stress distributions in steel water pipes produced by welding are predicted by a three-dimensional finite element method(FEM). Based on these results, stress distributions by welding and complex external forces are evaluated by adopting the same numerical method. The influence of some post weld heat treatments on residual stress distributions is also investigated.

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The literature study on Contact dermatitis (接觸性 皮膚炎에 關한 文獻的 考察)

  • Jeon, Jae-Hong;Kim, Hyun-A;Kang, Yun-Ho
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.10 no.1
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    • pp.263-283
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    • 1997
  • The study has been carried out to investigate of the Contact dermatitis by referring to 37 literature. The results were as follows; 1. In oriental medical science, Contact dermatitis is belong to the cartegory of the 'Chilchang(漆瘡)', 'Honyoja(狐尿刺)', 'Bunhwachang(粉花瘡)', 'Goyakpoong(膏藥風)', 'Matongsun(馬桶癬)'. 2. The cause of a disease is combination of internal factor-the weak of skin or the constitutional factor and external factor-the toxic substance. When the toxic substance contacts skin, pathologial change-stagnation of vital energy and blood(氣血鬱滯)-appears, and after the stagnation of vital energy and blood change heat(化火熱). 3. The symptom of a disease is topical itching, burning pain, erythematous papule, vesicle etc in skin in the acute state and itching, pachyderma, lichenification etc in skin in the chronic state. The symptom is differentiated to wind-heat(風熱) syndrom, damp-heat(濕熱) syndrom, toxic heat(熱毒) syndrom in the acute state and blood dryness(血燥) sydrom in the chronic state. 4. The treatment-methodes is as follow ; Until chung dynasty(淸代) the greater part of treatment is externl treatment The present age in china use together internal treatment and external treatment, in the acute state use method of remove heat(淸熱), remove wind(祛風), remove damp(利濕), detoxicating(解毒), remove heat from blood(凉血), in the chronic state use method of remove wind(祛風) and nourishing the blood(養血).

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Effectiveness of a Heat Transfer Characteristics of an Auxiliary Chamber for Performance of an Air Spring (보조용기의 열전달특성이 공기스프링의 성능에 미치는 영향)

  • Jang, Ji-Seong
    • Journal of Power System Engineering
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    • v.17 no.2
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    • pp.121-127
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    • 2013
  • The air spring is used widely because of the easy change of spring constant, and, a superior vibration and shock insulation performance. Among the apparatus using the merits of that, the air spring connected an auxiliary chamber has been developed and used as a component of suspension system for an automobile and a railroad car. The purpose of this study is to suggest a design method reflecting heat transfer effect for an air spring system connected auxiliary chamber. In order to do so, this study investigates change of reaction force along with variations in heat transfer coefficient, and, analyzes an effectiveness of a heat transfer characteristics of an auxiliary chamber for external force attenuation characteristics and impedance characteristics of an air spring connected an auxiliary chamber.