• Title/Summary/Keyword: heat and mass 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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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.

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.

Life Cycle Assessment for the Business Activities of Green Company -2. Mass Balance and Environmental Improvement (녹색기업의 사업활동 전 과정에 대한 환경성 평가 -2. 물질수지 및 환경개선)

  • Shin, Choon-Hwan;Park, Do-Hyun
    • Journal of Environmental Science International
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    • v.22 no.4
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    • pp.425-433
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    • 2013
  • A mass balance of process was calculated by using the analysis of basic unit and environmental assessment of all the processes of Busan fashion color industry cooperative that operates a combined heat and power plant and a bio treatment plant. The mass balance for the combined heat and power plant was done, based on boiler and water treatment processes while each unit reactor was used for the bio treatment plant. From the results above, a resource recycle network, a treatment flowchart for food waste water/wastewater treatment and a carbon reduction program were established.

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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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
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    • v.17 no.5
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    • pp.1-10
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    • 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.

Intake Valve Temperature Effect on the Mixture Preparation in a SI Engine During Warm-up

  • 신영기
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.5
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    • pp.51-66
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    • 1997
  • A heat transfer model of the intake valve in a spark ignition engine is presented, which is calibrated with a number of the valve temperature profiles measured during engine warm-up for the gaseous fuel(propane). The valve is divided into four identical elements for which the assumption of lumped thermal mass is applied. The calibration is made so that the difference between the measued and simulated valve temperatures becomes minimal. Then the model is applied to the cases of the liquid fuel(indolene) to estimate the amount of the liquid fuel vaporized from the intake valve by assuming that fuel evaporation accounts for the deficit of the heat balance budget. The results of the model show quantitative contribution of each heat transfer source to the heat balance. The behavior of the calculated mass fraction of the fuel vaporized from the intake valve explains how the liquid fuel evaporate during engine warm-up. The mass fraction at warmed-up condition is closely related with the fraction directly targeted on the valve back by the fuel spray geometry.

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Characteristics of Reduced Metal from Spent Oxide Fuel by Lithium

  • Kim Ik-Soo;Seo Chung-Seok;Shin Hee-Sung;Hwang Yong-Soo;Park Seong-Won
    • Nuclear Engineering and Technology
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    • v.35 no.4
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    • pp.309-317
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    • 2003
  • The mass balance of the unit processes of the Advanced spent fuel Conditioning Process was calculated to obtain basic information. Based on this mass balance, the changes in decay heat and radioactivity of the spent fuel due to the metallization in the high temperature molten salt system were estimated. The decay heat and the radioactivity were calculated by using the ORIGEN2 computer code, and the result showed that the decay heat and the radioactivity of the metallized spent fuel ingot were $24.27\%\;and\;24.24\%$, respectively, compared to those of oxide spent fuel.