• Title/Summary/Keyword: Inside temperature

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Characteristics of Cooling Temperature of Cold Water Pipes Buried in the Wall of a Small Mobile Modular House (소형 이동식 모듈주택의 벽면에 냉수배관 매설에 의한 냉방온도 특성)

  • Cho, Dong-Hyun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.3
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    • pp.110-117
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    • 2022
  • A chiller cooler absorbs the thermal energy of water to generate cold water and supplies the generated cold water to a cold water pipe buried in the wall of a small mobile modular house to greatly increase the cooling area. An attempt was made to reduce the required cooling time significantly. A small chiller cooler suitable for the cooling load of a small mobile modular house with an area less than 3.3 m2 was employed. When cooling is done during summer using a chiller cooler installed outdoors, heat absorption energy loss occurs in the cold water pipe owing to the high temperature. To address this, a study was conducted to reduce the endothermic energy loss significantly. As the mass flow rate of the cold water flowing inside the cold water pipe increased, the temperature decrease gradient of the cold water increased. From the start of the cooling operation, the air temperature of the small mobile modular house decreased linearly in proportion to the operation time. Furthermore, the temperature of the air inside the small mobile modular house decreased in proportion to the increase in the flow of water inside the cold water pipe.

Temperature Distributions inside a Space Heater for Greenhouse (I) - Temperature Characteristics with Heating Oil - (시설원예용 온풍난방기내의 온도분포에 관한 연구 (I) - 난방유 사용시 온도특성 -)

  • 서정덕;김종진;최규성;신창식;노수영
    • Journal of Biosystems Engineering
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    • v.24 no.4
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    • pp.335-342
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    • 1999
  • Air and flue gas temperature distributions in the space heater for greenhouse were measured to develop a thermal design technology for the space heater. Also, the characteristics of the fan supplying air to the space heater were investigated. The temperature of the flue gas inside the flue gas tube was linearly decreased as the lenght of than those of the flue gas with the oxygen concentration of 8.25% at the last exit of the second flue gas tube. Thus, the operating efficiency of the space heater could be increased with low air ratio decreased exhausting gas temperature and saved the energy consumption with decreased excess air flow. The temperature of the air supplied by fan was increased slowly around the first flue gas tube, meanwhile, increased sharply around the second flue gas tube due to large LMTD (Logarithmic Mean Temperature Difference) at the first flue gas tube than which of the second flue gas tube.

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Experimental Study on the Foaming Characteristics according to the Plastic Temperature and the Retention Time of Shale (혈암의 소성온도 및 체류시간에 따른 발포특성에 관한 실험적 연구)

  • Mun, Dong Hwan;Lee, Han Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.58-59
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    • 2018
  • In this study, firing experiments were carried out to confirm the foamability of the expansive shale collected from the local area. When expansive shales are subjected to high temperature heat, gas is generated inside and voids are formed. Due to this phenomenon, shale is used as a raw material for lightweight aggregate. Experiments were carried out with different plastic temperature and residence time to find the appropriate plastic temperature for this expansive shale. As a result, the higher the plastic temperature, the more the surface viscosity increased and the gas generated inside were retained. Resulting in a number of internal voids. However, even if the plastic temperature or the medium temperature is high, it is confirmed that sufficient gas is not generated when the residence time is shortened.

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An Effect of Wintertime Air Temperature on Crack Behavior at Downstream Face of the Concrete Gravity Dam (콘크리트 중력댐 하류면의 균열거동에 미치는 동절기 대기온도의 영향)

  • 장희석;김종수;심점식
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.1313-1318
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    • 2000
  • Crack behaviors at the downstream face of the concrete gravity dam were studied considering influence of the wintertime air temperature. It is assumed that inside area of 15m away from the dam surface in which temperature is presumed to be $15^{\circ}C$ is not affected from the annual air temperature variation. Water temperature at the upstream face and air temperature at the other faces were considered as outer boundary conditions to get temperature distribution inside of the dam using ADINA-T. These temperature distributions were transferred to FRANC2D to obtain equivalent stress intensity factors and crack propagation paths. Results obtained from changing initial crack locations and direction, air temperatures, and water levels were discussed. And crack behaviors at the upstream face were studied partly.

Resonance of Natural Convection and Heat Transfer inside a Square Cavity due to a Vibrating Wall (사각 공동구의 벽면 가진에 의한 자연 대류 유동의 공진 현상 및 열전달에 관한 연구)

  • Hur, N.;Kim, Y.;Kang, B.
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.483-488
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    • 2001
  • In the present study a numerical simulation is performed on a natural convection inside a square cavity with a vibrating wall. The study has been conducted varying the heat transfer rate, wall excitation frequency and also the orientation of the cavity. The temperature and velocities inside the cavity was observed and also, the heat transfer coefficients on the heating wall was seen. From the results, it can be seen that the temperature inside the cavity decreases when excited with the proper frequency and the heat transfer coefficient increased with cavity inclination angle, ${\theta}$. It is also found from the results that flow resonance is occurred near the inclination angle ${\theta}=90^{\circ}$.

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Simulation Analysis on the Air Flow Inside Computer Main Frame According to the Location of Fan (팬의 위치에 따른 컴퓨터 본체 내부의 공기유동에 관한 시뮬레이션 해석)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.2
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    • pp.259-266
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    • 2012
  • In this study, the temperature distributions are analyzed on the air flow according to the position of fan inside computer main frame by CFD simulation. In case that ventilation hole is existed at the side of computer frame, the air with lower temperature can be circulated near CPU radiant thermal panel. In case of installation with fan at the side panel, the temperature of air flow becomes lowest. The efficiency of thermal emission at personal computer and its durability can be improved by releasing a lot of heat at air flow effectively inside computer frame according to this simulation result.

Development of the Sunshade hat with a large brim (Part II) - Human trial test at outdoors - (양산형 일광차단모의 개발(제2보) -실외 인체착용시 복사열 및 자외선의 차단효과-)

  • 최정화;김경수
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.3_4
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    • pp.414-421
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    • 2004
  • To reduce farmer's stress from solar radiation and ultraviolet radiation(UV), the sunshade hat with a large brim and special structure for ventilation was developed and tested with manikin heads outdoors at previous study(Kim and Choi, 2002). To evaluate the protection efficiency of the sunshade hat, human trial test was performed at outdoors. The results were as follows; Skin temperatures(7 sites), heart rate, temperature inside the hats, temperature and relative humidity inside clothing on the back in wearing developed sunshade hat were significantly lower than those in wearing the controlled hat. In subjective sensation, subjects answered to feel significantly hotter, more humid and more uncomfortable in wearing the controlled hat. But relative humidity inside the hats was significantly higher in wearing developed hat. In rectal temperature, there were no significant differences between two hats.

Moisture Migration of Concrete Members under High Temperature (고온조건에서 콘크리트 부재의 수분이동)

  • Lee, Tae-Gyu;Kim, Hye-Uk
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1530-1535
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    • 2009
  • Moisture evaporates, when concrete is exposed to fire, not only at concrete surface but also at inside the concrete to adjust the equilibrium and transfer properties of moisture. The equilibrium properties of moisture are described by means of water vapor sorption isotherms, which illustrate the hysteretical behavior of materials. In this paper, the prediction method of the moisture distribution inside the high strength concrete members under the high temperature is presented. Finite element method is employed to facilitate the moisture diffusion analysis for any position of member. And the moisture diffusivity model of high strength concrete by high temperature is proposed. To demonstrate the validity of this numerical procedure, the prediction by the proposed algorithm is compared with the test result of other researcher. The proposed algorithm shows a good agreement with the experimental results including the vaporization effect inside the concrete.

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Comparative Analysis of Anion Concentration by the Type of Roadside Buffer Green (가로변 완충녹지의 조성유형에 따른 음이온 농도 비교 분석)

  • Yoon, Yong-Han;Joo, Chang-Hun;Park, Hun;Kim, Jeong-Ho
    • Journal of Environmental Science International
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    • v.23 no.7
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    • pp.1339-1347
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    • 2014
  • This study were performed on roadside buffer green in Songpa-dong, Songpa-gu, Seoul in order to analyze the anion concentration according to the type of composition of roadside buffer green. Buffer green separating the physical structure of the measurement points and measurement locations were separated by roadside, green interior, the other side of the road. planting density and deposit of trees per each buffer green was measured in the order of mounding type> slope type> the plain type. If the measured temperature of the location-specific weather elements roadside> inside> the other side of the road in order of measurement and the temperature is lowered farther away from the road. If the relative humidity of the road on the other side> inside> the roadside in order to measure and this is the opposite of the temperature tendency. According to physical structure reduction of the temperature on the other side of the road and roadside in order of mounding type> the plain type> slope type was measured. As a result of measuring a anion therefore concentration of the anion inside of melt is in order of mounding type> the plain type> slope type, tended to match the melt characteristics. According to measured positions anion concentration is in the order of the other side of the road> inside> the roadside was measured. As a result of correlation analysis, in the case of measurement location-specific weather and anions the temperature is positive correlation, relative humidity is negative correlation and that's results of previous studies were supported.

Layering Effects on Clothing Microclimate, Clothing Insulation and Physiological Responses

  • Park, Joonhee;Yoo, Shinjung
    • International Journal of Human Ecology
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    • v.14 no.2
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    • pp.93-103
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    • 2013
  • This study investigated the relationship of clothing microclimate and physiological responses in order to examine the layering effects on the clothing microclimate as an index to predict clothing thermal insulation ($I_{cl}$). Experiments were conducted in a $15^{\circ}C$ environment on six physically active males. Increased clothing layers resulted in higher mean temperature inside the clothing ($\bar{T}_{cl}$) and $I_{cl}$. The $I_{cl}$ had a high correlation with: $\bar{T}_{cl}$ (r = 0.556), the difference between the innermost surface temperature and the outermost surface temperature at the chest (DST) (r = 0.549) and the temperature inside clothing at the abdomen (r = 0.478). $\bar{T}_{cl}$ had the highest correlation with the temperature inside clothing at the abdomen (r = 0.889). $\bar{T}_{cl}$ also had the highest correlation with $\bar{T}_{sk}$ (r = 0.860). The results showed that the relationship between $I_{cl}$ and $\bar{T}_{cl}$ was linear (p < .01). Thermal comfort had a negative correlation with $\bar{T}_{cl-thigh}$ (r=-0.411) and $\bar{T}_{cl}$ (r = -0.323) (p < .01.)