• Title/Summary/Keyword: Heat balance

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Estimation of Expected Temperature Using Heat Balance Model and Observation Data

  • Kim, Eun-Byul;Park, Jong-Kil;Jung, Woo-Sik
    • Asian Journal of Atmospheric Environment
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    • v.9 no.3
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    • pp.214-221
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    • 2015
  • This study considers mean skin temperature to calculate expected temperature using the new heat balance model because the skin temperature is the most important element affecting the heat balance outdoors. For this, we measured the skin temperature in high temperature condition of Korea and applied it to calculate the expected temperature. The calculated expected temperature is compared with the result calculated using previous models which use the estimated mean skin temperature by considering metabolic rate only. Results show that the expected temperatures are higher when measured mean skin temperature is applied to the model, compared to the expected temperature calculated by applying mean skin temperature data calculated using metabolic rate like previous models. The observed mean skin temperature was more suitable for outside conditions and expected temperature is underestimated when mean skin temperature calculated by the equation using metabolic rate is used. The model proposed in this study has a few limitations yet, but it can be applied in various ways to facilitate practical responses to extreme heat.

Surface Heat Budget of the Northern Sea of Cheju Island for June-August 1993 and 1994 (제주도 북부해역의 표면 열수지 해석 -1993년과 1994년 하계의 경우-)

  • 김해동;양성기
    • Journal of Environmental Science International
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    • v.4 no.3
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    • pp.197-206
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    • 1995
  • Surface heat balance of the northern sea of Cheju Island for summer in 1993 and 1994 is analyzed using the observation data obtained by Marine Research Institute, Cheju National University. Each flux elements at the sea surface is derived from the marine meteorological reports with application of an aerodynamical bulk method for the turbulent heat fluxes, and empirical formulae for the long-wave radiation heat fluxes. The flux divergence of oceanic heat transport and the rate of heat storage in the ocean are estimated as residual. The features of the surface heat balance are mainly decided by the solar radiation flux and the latent heat flux for 199B. But the Bowen Ratios were large for 1993. This means that the sensible heat fluxes were nearly equal to the latent heat fluxes for 1993. In this period, mean flux divergence of oceanic heat transport is about 130 W/$m^2$.

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Effects of Dietary Fiber on Water Balance, Blood Acid-Base Balance, Body Temperature, and Metabolic Rate of Adult Roosters under Heat Stress (사료 섬유질이 고온 스트레스를 받는 수탉 성계의 수분 출납, 혈액의 산-염기 평형, 체온 및 대사율에 미치는 영향)

  • 이지훈;이봉덕;이수기;유동조;현화진
    • Korean Journal of Poultry Science
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    • v.22 no.3
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    • pp.133-144
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    • 1995
  • One metabolism trial(Experiment I) and another respiration trial(Experiment II) were conducted to investigate the effects of dietary fiber supplementation(20% wheat bran) on the water balance, blood acid-base balance, body temperature, and metabolic rate of heat-stressed adult roosters. In Experiment I, twenty 20-wk-old SCWL roosters(BW 1.6 kg) were randomly alloted to 4 treatments with 5 birds per treatment and one per replicate. The 4 treatments were consisted of two temperature(21~22˚C vs. 34~35˚C) and two dietary fiber treatment(0% and 20% wheat bran), making Experiment I a 2x2 factorial. After 4 d of preliminary period, birds we subjected to 3-d collection period. Sixteen 20-wk-old SCWL roosters(BW 1.6 kg) were employed Experiment H, with two temperature(21~22˚C vs. 34~35˚C) and two wheat bran levels(0% and 20%). Brids were housed in individual metabolism cages under normal temperature(21~22˚C), at fed one of the experimental diet. After 4 d of preliminary period, a respiration trial with open-circuit gravimetric respiratory apparatus was carried out for each bird for 6 h, one by one, normal(20~21˚C) and hot(34~35˚C) temperatures. The ANOVA test and comparisons among treatment means were done at 5% probability level for both experiments. Results obtained from Experiment I and, II were summarized as follows, 1.The amounts of DM intake and excretion were significantly(P<.05) decreased by heat stress. The DM intake was not affected by the addition of 20% wheat bran, however, the amount of DM excretion was significantly increased by the high fiber diet. Thus, the DM metabolizability decreased significantly by the addition of 20% wheat bran. 2. The heat-stressed roosters increased the water intake and excreta moisture content significantly. Although not significant, the water intake tended to increase in roosters fed the 20% wheat bran diet. 3. The amounts of total water input and evaporative water loss were increased significantly by heat stress, and the addition of 20% wheat bran did not exert any influence on the total water input and evaporative water loss. However, roosters fed the 20% wheat bran diet increased the excreta water output significantly. 4. Neither the heat stress nor the dietary fiber did affect the blood pH, pCO2, and HCO$_3$- significantly. 5. The body temperature increased significantly by the heat stress. However, the high fiber deit failed to decrease the body temperature. 6. The heat-stressed roosters decreased the 02 consumption and C0$_2$ production, and increased the evaporative water loss significantly. However, the high fiber diet did not exert any infulence in this regard. It appears that the beneficial effect, if any, of high fibrous diet during heat stress episode may be due to the increased heat loss through the enhanced excreta water.

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Study on Evaluation of Heat Demand and GIS Mapping in Costal Area (연안도시의 열 수요 추정 및 GIS Map 작성에 관한 연구)

  • Chung, Yong-Hyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.25 no.1
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    • pp.192-197
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    • 2013
  • To overcome the mismatch of heat demand and heat supply is important as considering point on heat utilizing aspects in Urban area. At this point, It need to know the plan of heat networks on the heat balance aspects. The purpose of this study is to know the method of heat evaluation on heat network around costal area. It is need to building uses to calculate the amounts of heat demand. 25 different types of building uses were supplied, but it was reclassified 10 types and calculated the amounts of heat demand in the costal area. The results was described on the area with GIS mapping.

The Development of a Heat Balance Evaluation Program for the Main Steam Line of LNG Carrier (LNG선 주증기계통의 열평형산전용 전산프로그램 개발)

  • 최순호
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.6
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    • pp.854-861
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    • 1998
  • The demand of LNG as a cheap and clean energy which does not cause an environmental problem has sharply been increased in Korea. In general LNG is stored in a cargo tank specially designed as a liquid state below $-162^{\circ}C$. The main engine of a LNG carrier is generally a steam boiler because LNG is a highly flammable fluid with the possibility of explosion. The main engine of a cargo ship has to be capable of the propulsion load and various auxiliary loads for the safe navigation since it is the primary energy source. Therefore the evaluation of a main boiler's energy capacity is a key design point in the planning of LNG carrier's construction. This research is to develop the computational program for the analysis of steam boiler Heat balance for LNG carrier.

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Metabolic Heat Production and Rectal Temperature of Newborn Calves

  • Mundia, C.M.;Yamamoto, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.3
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    • pp.304-307
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    • 1997
  • Rectal temperature (Tr), skin surface temperatures (Ts), and heart rate (HR) were measured continuously from birth (day 1) till day 7, while resting heat production (HP) was measured in a chamber on days 1, 3, 5 and 7, in order to study the characteristic variation of Tr in newborn calves by heat balance methods. Despite constant levels of milk being given to the newborn calves each day, daily mean resting HP was lowest on the day of birth, then increased to peak on day 3 and then decreased slightly thereafter. Daily mean HR was higher on days 2, 3 and 4, than on other days. Tr exhibited diurnal rhythms and daily mean Tr was low on day 1, high on day 3, and then decreased slightly after day 3. Daily average mean skin temperature (mTs) was similar on all days. Mean body temperature (Tb) exhibited diurnal rhythms and had a similar range between days, suggesting that heat balance and thermoregulation were carried out effectively on each day. The variation of Tb appeared to be synchronized with that of HP and suggested that newborn calves might use variations in the levels of Tb to facilitate the body's required levels of heart loss.

Simplified 1-Dimensional Model of Gas-Solid Reactor : Adapting to Coal Reduction Rotary Kiln (1차원 기체-고체 반응기 모델의 로터리킬른 환원로 적용)

  • Hahn, Taekjin;Choi, Sangmin
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.75-78
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    • 2012
  • Rotary kiln furnace is one of the most widely used reactors in industrial field. In this paper, 0-dimensional heat and mass balance for direct coal flame rotary kiln was performed preferentially, then a simplified 1-dimensional model was developed based on 0-dimensional analysis data to proceed additional thermal analysis. Compared the results with the currently operating rotary kiln data to validate 1-dimensional model. Through this procedure, it can help to derive fundamental idea for design and operation of rotary kiln.

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Thermodynamic Energy Balance Analysis of Underground Lined Rock Caverns (LRC) for Compressed Air Energy Storage (CAES) (복공식 지하 압축공기에너지 저장공동의 열역학적 에너지수지 분석)

  • Kim, Hyung-Mok;Park, Do-Hyun;Ryu, Dong-Woo;Choi, Byung-Hee;Song, Won-Kyong
    • Tunnel and Underground Space
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    • v.21 no.4
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    • pp.297-306
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    • 2011
  • In this paper, we performed thermodynamic energy balance analysis of the underground lined rock cavern for compressed air energy storage (CAES) using the results of multi-phase heat flow analysis to simulate complex groundwater-compressed air flow around the cavern as well as heat transfer to concrete linings and surrounding rock mass. Our energy balance analysis demonstrated that the energy loss for a daily compression and decompression cycle predominantly depends on the energy loss by heat conduction to the concrete linings and surrounding rock mass for a sufficiently air-tight system with low permeability of the concrete linings. Overall energy efficiency of the underground lined rock caverns for CAES was sensitive to air injection temperature, and the energy loss by heat conduction can be minimized by keeping the air injection temperature closer to the ambient temperature of the surroundings. In such a case, almost all the heat loss during compression phase was gained back in a subsequent decompression phase. Meanwhile, the influence of heat conductivity of the concrete linings to energy efficiency was negligible.

Estimated Advection Heat in the East/Japan Sea

  • Han, In-Seong;Kang, Yong-Q;Kim, Bok-Kee;Seong, Ki-Tack
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2003.11a
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    • pp.165-170
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    • 2003
  • A significant surface net heat loss appears around the Kuroshio and the Tsushima Warm Current regions. The area where the surface heat loss occurs should require heat to be supplied by the current to maintain the long-term annual heat balance. Oceanic heat advection in these regions plays an important role in the heat budget. The spatial distribution of the heat supply by the Tsushima Warm Current near the surface was examined by calculating the horizontal heat supply in the surface layer of the East/Japan Sea, directly from historical sea surface temperature and current data. We have also found a simple estimation of the effective vertical scale of heat supply by the current to compensate net heat loss using the heat supplied by the current in the surface 10m layer. The heat supplied by the current for the annual heat balance was large in the Korea/Tsushima Strait and along the Japanese Coast, and was small in the northwestern part of the East/Japan Sea. The amount of heat supplied by the current was large in the northwestern part and small in the southeastern part of the East/Japan Sea. These features suggest that the heat supplied by the Tsushima Warm Current is restricted to near the surface around the northeastern part and extends to a deeper layer around the southeastern part of the East/Japan Sea.

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Turbulence of the Coastal Atmospheric Surface Layer and Structure of the Coastal Atmospheric Boundary Layer (해안 대기 표층의 난류와 해안 대기 경계층의 구조)

  • Kwon, Byung-Hyuk
    • Journal of Fisheries and Marine Sciences Education
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    • v.17 no.3
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    • pp.404-412
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    • 2005
  • The surface energy budget depends on many factors, such as the type of surface, the soil moisture and the vegetation canopy, the geographical location, daily, monthly and seasonal variations, and weather conditions. In the coastal region, the surface is not homogeneous at various scales for instance water, sand, mud, tall grass, and crops. The energy balance over the vegetation canopy was analyzed with the optical energy balance measuring system. The latent heat flux was more intensive than the sensible heat flux. The sensible heat flux was very small in summer due to the canopy effect and higher in spring and autumn. In summer the development of the atmospheric boundary depended on rather the vertical shear of wind than the sensible heat flux.