• 제목/요약/키워드: Heat Insulation

검색결과 882건 처리시간 0.028초

동적계획법을 이용한 고온수배관의 최적보온설계에 관한 연구 (A study on the optimal design for heat insulation of hot water piping systems using a dynamic programming)

  • 유희한;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • 제11권1호
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    • pp.39-52
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    • 1987
  • Recently, the design problem of heat insulation have been reappraised in the aspect of energy saving due to the rising trend of energy cost. For example, that design problem is increasingly requsted in the fields of accommodation air conditioning systems, hot water supply systems, cargo handling systems, district heating or cooling systems. The rational design of heat insulation of piping systems can not only improve the overall efficiency of energy transfer but also give energy saving. In this paper, the heat insulation problem of district heating systems is therefore modeled as the multi-stage decision processes, suitable for dynamic programming technique. And take the object function as the sum of heat insulation material cost involved construction cost and heat loss cost, and propose the design method to minimize the object function for overall piping systems by dynamic programing. Effectiveness of design method presented here is proved by a computer simulation.

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Effects of SiC Particle Size and Inorganic Binder on Heat Insulation of Fumed Silica-based Heat Insulation Plates

  • Jo, Hye Youn;Oh, Su Jung;Kim, Mi Na;Lim, Hyung Mi;Lee, Seung-Ho
    • 한국세라믹학회지
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    • 제53권4호
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    • pp.386-392
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    • 2016
  • Heat insulation plates of fumed silica were prepared by mixing fumed silica, SiC powder and chopped glass fiber by a high speed mixer followed by pressing of the mixture powder in a stainless steel mold of $100{\times}100mm$. Composition of the plates, particle size of SiC, and type of inorganic binder were varied for observation of their contribution to heat insulation of the plate. The plate was installed on the upper portion of an electric furnace the inside temperature of which was maintained at $400^{\circ}C$ and $600^{\circ}C$, for investigation of heat transfer through the plate from inside of the electric furnace to outside atmosphere. Surface temperatures were measured in real time using a thermographic camera. The particle size of SiC was varied in the range of $1.3{\sim}17.5{\mu}m$ and the insulation was found to be most excellent when SiC of $2.2{\mu}m$ was incorporated. When the size of SiC was smaller or larger than $2.2{\mu}m$, the heat insulation effect was decreased. Inorganic binders of alkali silicate and phosphate were tested and the phosphate was found to maintain the heat insulation property while increasing mechanical properties.

남부지역 주거건물의 외피단열변화에 따른 에너지소비량 예측 (Prediction of the Amount of Energy Consumption by Variation in Envelope Insulation on a Detached House in Southern Part of Korea)

  • 문진우;한승훈;오세규
    • 한국주거학회논문집
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    • 제22권1호
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    • pp.115-122
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    • 2011
  • This study aimed at quantifying the impact of envelope insulation on energy consumption for thermal controls in residential buildings in southern part of Korea. A series of parametric simulations for a range of R-values of walls, roof, floor, and windows were computationally conducted for a prototypical Korean detached house. Analysis revealed that the total amount of heat gain was larger than that of heat loss, while the amount of energy for cooling was smaller than that for heating due to the difference of system efficiency; the envelope heat transfer was more significant for the heat loss, thus, the increase of the envelope insulation was more effective to reduce heating load; and there were certain levels of envelope insulation after which the energy saving effect was not significant. These findings are expected to be a fundamental database for the decision of proper insulation level in Korean residential buildings.

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

  • 류화성;신상헌;송성용;김득모
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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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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한중콘크리트 보온양생 공법에 대한 VE분석 (Value Engineering Approach for Heat Curing Method Under Cold Weather Condition)

  • 우대훈;김태청;김종;전충근;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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    • pp.21-23
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    • 2010
  • This study was conducted to draw various decisive elements of a reasonable heat curing method and to examine the importance in deciding a construction method when constructing cold weather concrete. As a result, the items proposed as important elements at the time of decision of a heat curing method included economy, workability, maintainability, insulation capability, reduced construction period and usability. As a result of importance by items under AHP technique, it was found the most important element was insulation capability, followed by reduced construction period and workability. As a result of comparison of a heat supplying and a heat insulation method by dual bubble sheet differed 2 times as much as a heat supplying method, especially the evaluation degree by insulation capability and reduced construction period was high.

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전통 농촌주택(흙집) 심벽의 단열 특성 (Characteristics of Insulation of Core Wall for Traditional Rural House (Earthen House))

  • 리신호
    • 한국농공학회지
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    • 제45권5호
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    • pp.126-132
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    • 2003
  • The insulation characteristics of earthen core wall were studied in this paper. The overall heat transfer coefficients(U) were obtained through experiment in accordance with Korea Industrial standards. The result of the experiment are compared with the Regional Overall Heat Transfer Coefficient(U) of Building. This results inform that core wall with soil can be used as building walls because the insulation characteristics agree to the rule of building standards.

A Study on the Physical Properties of Mineral Hydrate Insulation Material Mixed with Basalt Fiber

  • Park, Jae-Wan;Chu, Yong-Sik;Seo, Sung-Kwan;Jeong, Jae-Hyen
    • 한국세라믹학회지
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    • 제53권1호
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    • pp.63-67
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    • 2016
  • Mineral hydrate is a new insulation material that compensates for the defects of existing materials. Mineral hydrate is made of inorganic ingredients; therefore, it is nonflammable. The porous structure of mineral hydrate makes the material lightweight and insulating. Mineral hydrate insulation and similar products have been studied and manufactured in Korea and abroad. However, these insulation materials need to improve in terms of strength. In this study, basalt fiber was used to enhance the strength. In order to observe the property changes, compressive strength, heat conductivity, and specific gravity were measured and XRD pattern analysis was performed. These tests confirmed that basalt fiber was effective at improving the strength and lowering the heat conductivity of mineral hydrate insulation.

The Model and Experiment for Heat Transfer Characteristics of Nanoporous Silica Aerogel

  • Mingliang, Zheng
    • 한국재료학회지
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    • 제30권4호
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    • pp.155-159
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    • 2020
  • Nanoporous silica aerogel insulation material is both lightweight and efficient; it has important value in the fields of aerospace, petrochemicals, electric metallurgy, shipbuilding, precision instruments, and so on. A theoretical calculation model and experimental measurement of equivalent thermal conductivity for nanoporous silica aerogel insulation material are introduced in this paper. The heat transfer characteristics and thermal insulation principle of aerogel nano are analyzed. The methods of SiO2 aerogel production are compared. The pressure range of SiO2 aerogel is 1Pa-atmospheric pressure; the temperature range is room temperature-900K. The pore diameter range of particle SiO2 aerogel is about 5 to 100 nm, and the average pore diameter range of about 20 ~ 40 nm. These results show that experimental measurements are in good agreement with theoretical calculation values. For nanoporous silica aerogel insulation material, the heat transfer calculation method suitable for nanotechnology can precisely calculate the equivalent thermal conductivity of aerogel nano insulation materials. The network structure is the reason why the thermal conductivity of the aerogel is very low. Heat transfer of materials is mainly realized by convection, radiation, and heat transfer. Therefore, the thermal conductivity of the heat transfer path in aerogel can be reduced by nanotechnology.

고온초전도 케이블용 cryostat의 단열조건에 대한 열침입량 측정 (Experiment on Heat Loads Invaded into HTS Cable Cryostat under Cryogenic Insulation System)

  • 김도형;정원묵;김동락;양형석;조승연;황시돌
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1564-1569
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    • 2004
  • Insulating a heat from the environment is the most important in cryogenic applications like HTS cable system. Vacuum and MLI(Multi-Layer Insulation) have been widely used to get highly efficient cryogenic insulation. In this study, experiment on annular cylinder regarded as basic model of HTS cable cryostat has been performed to measure the heat loads. To investigate the effectiveness of radiation shields in cryogenic insulation system, the experiments are carried out to various number of the shields. The measured values are compared with the results estimated theoretically. The heat loads invaded from the environment was determined by liquid nitrogen boil-off calorimetry.

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Efficient Cooling Method for a Cu Coil in an Induction Cooker by Using an Insulation Sheet

  • Kwon, Jong-Han;Nam, Yoon-Jae;Shin, K.H.;Lim, S.H.
    • Journal of Magnetics
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    • 제16권1호
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    • pp.31-35
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    • 2011
  • A silica aerogel sheet with a very low thermal conductivity is used to suppress the temperature increase of the Cu coil in an induction cooker by reducing the heat flow from the heat source (cooking pot). It is found that the temperature of the Cu coil is reduced significantly by the insertion of an insulation sheet between the heat source and the Cu coil, demonstrating the effectiveness of the insulation sheet in the suppression of the heat flow between the cooking pot and the coil. Furthermore, the temperature of the cooking pot increases more rapidly with the use of the insulation sheet, allowing for an increased efficiency of the induction cooker.