• Title/Summary/Keyword: Heat balance

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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
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    • v.5 no.3
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    • pp.181-188
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    • 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.

A Study on Heat and Mass Balance in a Coal Gasifier (석탄 가스화기 열 및 물질정산에 관한 연구)

  • Kim, Bong-Keun;Yoo, Jeong-Seok;Kim, You-Seok
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.11a
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    • pp.424-428
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    • 2007
  • In the current most tool using heat and mass balance in a coal gasifier is dependent on commercial code such as STANJAN, CHEMKIN. However, in order to keep the self-reliance technology, it is necessary to develop the original design tool available for comprehension and analysis on the spot. So in this study, its own heat and mass balance program is developed on the assumption that the process in a coal gasifier is adiabatic and quasi-equilibrium. The mass balance is calculated by using the chemical equilibrium principle. Also the heat and mass balance according to main operating factors such as temperature, pressure and O2/Coal ratio, was carried in this tool. This heat and mass balance was verified on the basis of the results simulated in STANJAN, commercial codes using similar logic.

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Evaluation of Heat Balance for Cooling System of an Armored Installation in Small Space (좁은 공간 내의 밀폐형 장치 냉각시스템에 대한 열평형 평가)

  • Kim, Sung-Kwang;Ahn, Seok-Hwan;Nam, Ki-Woo
    • Journal of Ocean Engineering and Technology
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    • v.21 no.3 s.76
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    • pp.1-7
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    • 2007
  • In this study, the heat balance test of an engine was conducted, and the heat released to coolant is measured and corrected using a power adjustment factor for high fuel temperature to simulate heat rejection of the engine. An engine-converter matching simulation program which can compute the engine speed, transmission output speed, transmission input and output power is developed from the vehicle, transmission and engine performance curve. With this information and the engine heat rejection characteristics, the engine and transmission heat rejection rates can be determined at given condition. In analyzing the air mass flow, a sub program computing the air mass flow rate from the equation of the pressure balance between cooling fan static pressure rise and pressure losses of cooling components is developed.

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
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    • v.24 no.6
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    • pp.721-729
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    • 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.

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

  • Han, In-K.
    • Journal of Nutrition and Health
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    • v.1 no.1
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    • pp.33-36
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    • 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.

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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
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    • v.7 no.4
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    • pp.417-424
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    • 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.

A Numerical Study on the Design of Exchanger for Desiccant Dehumidifier (데시칸트 제습기용 열교환기 설계에 관한 수치해석적 연구)

  • Kim, Chi-Wan;Ahn, Young-Chull;Kim, Gil-Tae
    • Journal of Power System Engineering
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    • v.17 no.6
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    • pp.54-62
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    • 2013
  • A numerical analysis is performed to evaluate mass flow balance in the heat exchanger for the dehumidifier. To improve the mass flow balance for maximum heat transfer performance, inlet, outlet and baffle are changed. Mass flow balance is evaluated by non-uniformity of flow which is the same concept with the standard deviation. Usually, there will occur many paths between the inlet and the outlet, however, it will follow shortest and low resistance ways. The uniform distribution of flow is numerically analyzed for several types of heat exchangers. Making the shortest way between the inlet and the outlet is most important factor. Two types of heat exchangers are installed in the dehumidifier and 4 cases of Type A heat exchangers and 3 cases of Type B heat exchangers are evaluated and optimized. The result of this research is applied to design heat exchanger for commercial dehumidifiers.

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

  • 방성호;이대욱;이광순;이석호;손종상;윤상철
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.595-600
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    • 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.

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Lifter Design for Enhanced Heat Transfer in Rotating Counter-Current Flow Reactor and Application to One Dimensional Heat Balance Model (회전식 대향류 반응기 내 열전달 증진을 위한 리프터 설계와 1차원 열평형 모델로의 적용)

  • Lee, Hookyung;Choi, Sangmin
    • 한국연소학회:학술대회논문집
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    • 2013.06a
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    • pp.51-54
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    • 2013
  • Rotary kiln reactors are frequently equipped with an axial burner with which solid burden material is directly heated. Lifters are commonly used along the length of the system to lift particulate solids and increase the heat transfer between the solid bed and the combustion gas. The material cascading from the lifters undergoes drying and reacting through direct contact with the gas stream. In this study, volume distribution of materials held within lifters was modeled according to the different lifter configuration and appropriate configuration was used for the design purpose. This was applied to the one-dimensional heat balance model of a counter-current flow reactor, which contributes to the increase of the effective contact surface, and thereby enhances the heat transfer.

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