• Title/Summary/Keyword: Heat balance method

Search Result 194, Processing Time 0.025 seconds

Heat Production Determined by the Respiration-Calorimetric Method and Body Balance Method

  • Han, In-K.
    • Journal of Nutrition and Health
    • /
    • v.1 no.1
    • /
    • pp.33-36
    • /
    • 1968
  • Amounts of heat production determined by two indirect calorimetric methods, i.e., respiration-calorimetric method and body balance method were compared. In this report the apparatus, its operation and computation procedures for Haldane respiration-calorimetry modified by Han as well as procedures for body balance method are described. It was found that the heat production measured by two methods are similar.

  • PDF

Automation of Heat & Mass Balance Design Optimization Method for Power Plant (화력발전시스템 Heat and Mass Balance 최적설계 자동화기법)

  • Baek, SeHyun;Jang, jihoon;Kim, YoungJoo
    • KEPCO Journal on Electric Power and Energy
    • /
    • v.5 no.3
    • /
    • pp.181-188
    • /
    • 2019
  • In this study, the Heat & Mass balance design optimization tool has developed by linking the design input/output variables with the Heat & Mass balance calculation solver and optimization algorithm and also automating the iterative calculation process. As a result of testing this optimization tool for 10 kinds of power plant, it was expected to improve the NPV and IRR compared with general design methods.

Analysis of Two-Dimensional Transient Heat Conduction Problems in a Finite Strip by the Heat Balance Integral Method (熱平衡積分法에 의한 有限 Strip에서의 2次元 過渡熱傳導 問題의 解析)

  • 서정일;조진호;조종철
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.7 no.4
    • /
    • pp.417-424
    • /
    • 1983
  • This paper presents two methods of obtaining approximate analytic solutions for the temperature distributions and heat flow to two-dimensional transient heat conduction problems in a finite strip with constant thermal properties using the Heat Balance Integral. The methods introduced in this study are as follows; one using the Heat Balance Integral only, and the other successively using the Heat Balance Integral and an exact analytic method. Both methods are applicable to a large number of the two-dimensional unsteady conduction problems in finite regions such as extended surfaces with uniform thickness, but in this paper only solutions for the unsteady problems in a finite strip with boundary condition at the base expressed in terms of step function are provided as an illustration. Results obtained by both methods are compared with those by the exact two-dimensional transient analysis. It is found that both approximate methods generate small time solutions, which can not be obtained easily by any exact analytic method for small values of Fourier numbers. In the case of applying the successive use of the Heat Balance Integral and Laplace transforms, the analysis shows good agreement with the exact solutions for any Fourier number in the range of Biot numbers less than 0.5.

Daily Variation of Heat Budget Balance in the Gangjeong-Goryung Reservoir for Summertime - Concerning around the Rate of Heat Storage - (낙동강 강정고령보의 여름철 열수지 일변화 - 열 저장량 변동을 중심으로 -)

  • Kim, Seong-Rak;Cho, Chang-Bum;Kim, Hae-Dong
    • Journal of Environmental Science International
    • /
    • v.24 no.6
    • /
    • pp.721-729
    • /
    • 2015
  • Surface heat balance of the Gangjeong-Goryung Reservoir is analyzed for 12-17 August 2013. Each flux elements at the water surface is derived from the special field observations with application of an aerodynamical bulk method for the turbulent heat fluxes and empirical formulae for the radiation heat fluxes. The rate of heat storage in the reservoir is estimated by using estimated by surface heating rate and the vertical water temperature data. The flux divergence of heat transport is estimated as a residual. The features of the surface heat balance are almost decided by the latent heat flux and the solar radiation flux. On average for 12-17 August 2014 in the Gangjeong- Goryung Reservoir, if one defines the insolation at the water surface as 100 %, 94 % is absorbed in the reservoir; thereafter the reservoir loses about 30~50% by sensible heat, latent heat and net long-wave radiation. The residue of 50~80 % raises the water temperature in the reservoir or transported away by the river flow during the daytime.

Reaction heat estimation of industrial batch reactors (산업용 회분식 반응기에서의 반응열 추정)

  • 방성호;이대욱;이광순;이석호;손종상;윤상철
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1993.10a
    • /
    • pp.595-600
    • /
    • 1993
  • The heat of reaction has been estimated from heat balance relationships around the reactor. The heat balance equations were formulated with the assumptions that the reactor temperature is uniformly distributed and the jacket temperatures are axially distributed. We have obtained the temperature distribution of jacket contents by FDM. And then, we have rearranged the heat balance equations so that the heat of reaction can be estimated from the finite number of temperature measurements, i.e., temperatures of the reactor contents, at the jacket inlet and outlet, respectively. The proposed method for reaction heat estimation on were applied to industrial batch reactors ; one is ABS polymerization reactor and the other is SAN polymerization reactor. We have also examined the variation of overall heat transfer coefficients for the reactors during reaction.

  • PDF

Heat Transfer Analysis in a Straight Fin of Trapezoidal Profile by the Heat Balance Integral Method (열평형적분법에 의한 사다리꼴단면의 직선휜에서의 열전달해석)

  • Jo Jong-Chull;Cho Jin-Ho
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
    • /
    • v.11 no.3
    • /
    • pp.1-8
    • /
    • 1982
  • When exact analytical solutions to certain type of heat conduction problems are quite cumbersome or not obtainable, it is important to introduce approximate analytical methods which are simple and useful compared with numerical methods. In this study, therefore, the Heat Balance Integral Method is applied to analysis of steady-state conduction in a straight fin of trapezoidal profile, and the two-dimensional temperature distribution in the fin and the approximate fin efficiency are obtained. Results are compared with those by the one- dimensional analysis and two-dimensional numerical analysis for a wide range of Biot numbers. It is shown that the two-dimensional temperature distribution obtained by the integral method is in good agreement with that by the finite element method at Biot numbers for which the result by the one-dimensional analysis is unreliable.

  • PDF

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
    • /
    • v.4 no.3
    • /
    • pp.197-206
    • /
    • 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/$m^2$.

  • PDF

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
    • /
    • v.25 no.1
    • /
    • pp.192-197
    • /
    • 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.

Theoretical Study on Snow Melting Process on Porous Pavement System by using Heat and Mass Transfer (열전달 및 물질전달을 이용한 공극 발열도로에서의 융설 해석에 대한 이론적 연구)

  • Yun, Taeyoung
    • International Journal of Highway Engineering
    • /
    • v.17 no.5
    • /
    • pp.1-10
    • /
    • 2015
  • PURPOSES : A finite difference model considering snow melting process on porous asphalt pavement was derived on the basis of heat transfer and mass transfer theories. The derived model can be applied to predict the region where black-ice develops, as well as to predict temperature profile of pavement systems where a de-icing system is installed. In addition, the model can be used to determined the minimum energy required to melt the ice formed on the pavement. METHODS : The snow on the porous asphalt pavement, whose porosity must be considered in thermal analysis, is divided into several layers such as dry snow layer, saturated snow layer, water+pavement surface, pavement surface, and sublayer. The mass balance and heat balance equations are derived to describe conductive, convective, radiative, and latent transfer of heat and mass in each layer. The finite differential method is used to implement the derived equations, boundary conditions, and the testing method to determine the thermal properties are suggested for each layer. RESULTS: The finite differential equations that describe the icing and deicing on pavements are derived, and we have presented them in our work. The framework to develop a temperature-forecasting model is successfully created. CONCLUSIONS : We conclude by successfully creating framework for the finite difference model based on the heat and mass transfer theories. To complete implementation, laboratory tests required to be performed.

A Study on the Heat Balance of Cooling System for Armored Vehicles (밀폐형 차량 냉각시스템에 대한 열평형 연구)

  • Kim, S.K.;Ahn, S.H.;Nam, K.W.
    • Journal of Power System Engineering
    • /
    • v.11 no.1
    • /
    • pp.70-75
    • /
    • 2007
  • Heat transfer coefficient and fin efficiency of a heat exchanger dispersed in the microelement of control volume were predicted with various flow patterns, conditions and material properties. A computational program was developed by using the method of efficiency-NTU(Number of transfer unit). The modelling was applied to heat exchangers, also was integrated in power pack cooling system in an armored vehicle. The compatibility and the generality were proved by comparing the prediction values with the test results. The developed program may be useful for the design of the cooling system in an armored vehicle.

  • PDF