• Title/Summary/Keyword: Radiation heat

Search Result 1,421, Processing Time 0.023 seconds

Effects of Nutritional State on Physiological Responses and Heat Production During Exercise of the Animal - a Review

  • Kasa, I Wayan
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.11 no.4
    • /
    • pp.331-336
    • /
    • 1998
  • This review was conducted to analyse the effect of nutrition on physiological responses; heat production of domestic animal during exercise. Overall, it can be concluded that the major factors likely to affect heat production in domestic animals during exercise (including work load) are body weight, speed, the gradients attempted, feed intake, ambient conditions (including temperature and solar radiation) and altitude. On nutrition-exercise interactions, for example, it has been concluded that animals on better quality diets produce more heat than those on poorer quality ones, and that glucose as well as acetate are metabolized as energy sources during both rest and exercise.

Analysis of the Relations Between Design Parameters and Performance in the Passive Safety Decay Heat Removal System

  • Sim, Yoon-Sub;Wi, Myung-Hwan;Kim, Eui-Kwang;Min, Beong-Tae
    • Nuclear Engineering and Technology
    • /
    • v.31 no.3
    • /
    • pp.276-286
    • /
    • 1999
  • A computer code PARS2 is developed for the analysis of PSDRS, which is the safety grade RHRS of HAMMER, and applied to the investigation of the relation between design parameters and performance of PSDRS. The concept of the heat transfer resistance network is applied in assessing the importance of the various heat transfer modes. From the analysis results, the qualitative relations between the PSDRS performance and design parameters are found and guidelines for the PSDRS design procedures are also proposed.

  • PDF

Numerical modeling of Atmosphere - Surface interaction considering Vegetation Canopy (식물계를 고려한 지표-대기 상호작용의 수치모의)

  • 이화운;이순환
    • Journal of Environmental Science International
    • /
    • v.3 no.1
    • /
    • pp.17-29
    • /
    • 1994
  • An one dimensional atmosphere-vegetation interaction model is developed to discuss of the effect of vegetation on heat flux in mesoscale planetary boundary layer. The canopy model was a coupled system of three balance equations of energy, moisture at ground surface and energy state of canopy with three independent variables of $T_f$(foliage temperature), $T_g$(ground temperature) and $q_g$(ground specific humidity). The model was verified by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HYPEX-MOBHLY experiment. As the result, both vegetation and soil characteristics can be emphasized as an important factor iii the analysis of heat flux in the boundary layer. From the numerical experiments, following heat flux characteristics are clearly founded simulation. The larger shielding factor(vegetation) increase of $T_f$ while decrease $T_g$. because vegetation cut solar radiation to ground. Vegetation, the increase of roughness and resistance, increase of sensible heat flux in foliage while decrease the latent heat flux in the foliage.

  • PDF

Natural Weathering of Wood Heat-Treated at $220^{\circ}C$

  • Kang, Ho-Yang
    • Journal of the Korea Furniture Society
    • /
    • v.19 no.6
    • /
    • pp.460-465
    • /
    • 2008
  • When wood is exposed to natural weathering and UV radiation discoloration progresses. The color variation of heat-treated wood was investigated. Four domestic species were selected and heat-treated at $220^{\circ}C$ and naturally weathered for 42 days. Their colors were measured with a portable colorimeter. The color variations were different between species. The Korean red pine specimens were highly discolored by the natural weathering even though they were heat-treated. In contrast to Korean red pine, Korean pine is less discolored. The maximum color difference of larch was lower than Korean red pine. All specimens of birch exceeded the color difference criterion of 15 after 25 hours with the maximum of 28.

  • PDF

The Application of Gas-Solid Reactor Model: Consideration of Reduction reaction model (기체 고체 반응기 모형의 응용: 환원로 반응 모형 고찰)

  • Eum, Minje;Choi, Sangmin
    • 한국연소학회:학술대회논문집
    • /
    • 2012.11a
    • /
    • pp.79-82
    • /
    • 2012
  • The gas-solid reactor, such as rotary kiln, sintering bed, incinerator and CFB boiler, is the one of most widely used industrial reactors for contacting gases and solids. the gas-solid reactor are mainly used for drying, calcining and reducing solid materials. In the gas-solid reactor, heat is supplied to the outside of the wall or inside of the reactor. The heat transfer in gas-solid reactor encompasses all the modes of transport mechanisms, that is, conduction, convection and radiation. The chemical reactions occurring in the bed are driven by energy supplied by the heat transfer. This paper deal with the effect of heat transfer and chemical reaction in the gas-solid reactor.

  • PDF

Performance Analysis of the BIPV/T system by the performance Test- Part1. PV efficiency (실험을 통한 BIPV/T 시스템 성능분석-1. PV 발전효율)

  • Lee, Hyeon-Ju;Jo, Hye-Jin
    • 한국태양에너지학회:학술대회논문집
    • /
    • 2012.03a
    • /
    • pp.445-450
    • /
    • 2012
  • BIPV/T (Building Intergrated PhotoVoltaic/Thermal) is combined system produces electricity and thermal energy. The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. The efficiency of the PV system's performance will raise by the system removes heat from the PV. The test system is installed to top floor of the experimental house in the KEPCO Research Institute. The planned experiment is following. (1) Supplying heat energy to top floor. (2) Supplying heat and cool energy to thermal storage in the bottom of the top floor. (3) Supplying heat energy to EHP for improved performance. The experimental performance is executed from 13th February to 13th March, 2012. The solar generation of electricity is 4.04kWh under the horizontal solar radiation is $1000W/m^2$ and the air temperature is $25^{\circ}C$.

  • PDF

Study on the Performance Analysis of Solar Heating System with Cloud Cover (운량에 따른 태양열 시스템의 성능 분석에 관한 연구)

  • Kim, Won-Seok;Pyo, Jong-Hyun;Cho, Hong-Hyun;Ryu, Nam-Jin
    • Proceedings of the SAREK Conference
    • /
    • 2009.06a
    • /
    • pp.1215-1219
    • /
    • 2009
  • In this study, the performance of solar assisted hybrid heat pump system with cloud cover were analyzed by using experimental method in spring season. It was consisted of concentric evacuated tube solar collector, heat medium tank, heat storage tank, heat pump, and so on. As a result, the solar radiation should be maintained over $4.1\;MJ/m^2$ in order to operate solar heating system for heating. Solar heat of collector wasn't affected by ambient temperature, but cloud cover has a big effect to collector efficiency. In addition, the collector efficiency is about 50-60%, and solar fraction is 40% for this system.

  • PDF

Calculation of the Convective Mixed Layer by Estimation of Sensible Heat Flux (현열 플럭스 추정에 의한 대류 혼합층 고도의 산출)

  • 김용국
    • Journal of Environmental Science International
    • /
    • v.7 no.5
    • /
    • pp.639-645
    • /
    • 1998
  • A Jump model was evaluated for the calculation of hourly mixing height and mean potential temperature within the height. The Sump model was modified for estimation of downward heat fluxes by mechanical convections and surface heat fluxes. The surface heat fluxes were estimated from routine weather data such as solar radiation and air temperature. Total of 8 upper-air data observed at 0000UTC and 0600UTC in Osan station during April 23 to 26, 1996 were analyzed, and compared to the model results in detail. The calculated mixing heights and potential temperatures within the height were comparable to the observations, but some differences were showed. The calculated mixing heights were generally higher than observations. And, when variations of wind directions were large, the large difference of potential temperature was occurred. From the results, it was important to note that vortical motions and advections of air masses would affect to the growth of the mixing height.

  • PDF

A Case Study on The Reduction and Examination for Noise and Vibration of Backpass Heat Surface in the Power Plant Boiler (발전용 보일러의 후부 전열면 소음진동 저감에 관한 사례 연구)

  • Lee, Gyoung-Soon;Lee, Tae-Hoon;Moon, Seung-Jae;Lee, Jae-Heon
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2008.03b
    • /
    • pp.642-647
    • /
    • 2008
  • The boiler structure is determined by combustion characteristics and construction costs in the combustion chamber of a large commercial boiler. The heat transfer in boiler is composed of the radiation and the convection. The convective heat transfer has happened to back-pass heating surface. The combustion gas sequentially passes through the reheater tube, 1st economizer tube, and 2nd economizer tube. In case of being lowered in boiler height, we have to install additional tube bundle in back-pass heating surface for increasing the heat transfer of boiler, which causes the noise and vibration from combustion gas. When the combustion gas passes through the back-pass tube bundle in specified load of commercial boiler, this paper analyzes the acoustic characteristics between vortex-shedding frequency and natural frequency in tube bundle cavity. The case study reduce the resonance by changing natural frequency characteristics of tube-bundle cavity using a way to install ant-noise baffle in the direction of combustion gas flow.

  • PDF

HEAT AND MASS TRANSFER EFFECTS ON MHD NATURAL CONVECTION FLOW PAST AN INFINITE INCLINED PLATE WITH RAMPED TEMPERATURE

  • SHERI, SIVA REDDY;SURAM, ANJAN KUMAR;MODULGUA, PRASANTHI
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.20 no.4
    • /
    • pp.355-374
    • /
    • 2016
  • This work is devoted to investigate heat and mass transfer effects on MHD natural convection flow past an inclined plate with ramped temperature numerically. The dimensionless governing equations for this investigation are solved by using finite element method. The effects of angle inclination, buoyancy ratio parameter, permeability parameter, magnetic parameter, Prandtl number, heat generation, thermal radiation, Eckert number, Schmidt number, chemical reaction parameter and time on velocity, temperature and concentration fields are studied and presented with the aid of figures. The effects of the pertinent parameters on skin friction, rate of heat transfer and mass transfer coefficients are presented in tabular form. The numerical results are compared graphically with previously published result as special case of the present investigation and results found to be in good agreement.