• Title/Summary/Keyword: Combustion heat

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Measurement of Radiative Heat Flux of Nozzle Exit (노즐 후방부의 Radiative Heat Flux 측정)

  • An, Won Geun;Park, Hui Ho;Hwang, Su Gwon;Kim, Yu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.5
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    • pp.87-92
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    • 2003
  • In rocket systems, somtimes special devices or equipments are installed near the nozzle exit area where high temperature and pressure combustion gas flows. To pretect these subsystems from severe thermal environment, it is necessary to have accurate thermal data measured from the experimental liquid rocket firing test. Test variables were combustion pressure (200, 300, 400 psi) and mixture ratio (1.5, 2.0, 2.5) and quartz was used as a heat probe. Measurement technique used in this research can be also applied to measure the radiative heat flux inside the combustion chamber which is important imput data for the liquid rocket regenerative cooling system design.

Computational Simulation to Predict Emissions of a Heat Recovery Steam Generator (가스터빈 열 회수 증기 발생기의 배출 가스 예측 모사 해석)

  • Han, Woojoo;Jang, Jihoon;Lee, Youngjae;Han, Karam;Huh, Kang Y.
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.67-70
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    • 2014
  • We performed computational simulation for a heat recovery steam generator to predict emissions (especially carbon monoxide) and compare the results with experimental data. We used the steady laminar flamelet model(SLFM) which can consider detailed chemical mechanisms. To reduce the number of grid, we simplified the geometry of the whole heat recovery steam generator. In conclusion, the trend of simulation results is good agreement with experimental data.

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A Study on the Modelling of Combustion in a Small DI Diesel Engine (소형 DI 디젤 기관의 연소 모델링에 관한 연구)

  • Koh, D.K.;Kim, K.H.;Jang, S.H.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.2 no.2
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    • pp.20-26
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    • 1998
  • Heat release data were obtained by analysis of cylinder diagrams from a test engine, naturally-aspirated small-size four-stroke DI diesel engine. These data were used to decide empirical coefficients of Whitehouse-Way's model, single zone combustion model. Finally, the comparison of calculated with experimental results was performed, and the accuracy of calculated versus experimental data of the model in predicting engine heat release and cylinder pressure was demonstrated.

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Thermal Characteristics of a Solar and Gas-fired Receiver (태양열과 가스 연소열을 복합 적용한 흡수기의 열특성 연구)

  • Kang, Myeong-Cheol;Kim, Jin-Soo;Kang, Yong-Heack;Yoon, Hwan-Ki;Yu, Chang-Kyun;Lee, Sang-Nam
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.157-160
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    • 2006
  • The Dish/Stirling system with the Stirling engine is currently used to convert solar energy directly to electrical energy successful operation of dish/Stirling system is supported by hybrid system, which will allow continuous operation driven by solar and combustion heat ins. The hybrid Receiver has to be provided with an additional combustion system. The heat pipe receiver and conbustion system were manufactured and tested for thermal characteristics of receiver. Maximum temperature difference along the heat pipe surface is $200^{\circ}C$. Emission measurements showed low NOx values of 28 to 46 ppm and very high CO values of 18 to 201 ppm.

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Modeling of Coke Combustion and Heat Transfer in an Iron Ore Sintering Bed with Considerations of Multiple Solid Phases (다중 고체상을 고려한 소결기의 코크스 연소-열전달 모델링)

  • Yang, Won;Ryu, Chang-Kook;Choi, Sang-Min
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.79-84
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    • 2003
  • In this study we propose an unsteady I-dimensional model of an iron ore sintering bed with multiple solid phases, which confers a phase on each solid material. This model contains coke combustion, limestone decomposition, gaseous reaction, heat transfers between each phase, and geometric changes of the solid particles. Simulation results are compared with the limited experimental data set of various coke contents and air supply rates. Effect of the coke diameter is also evaluated. They predict the experimental results well and show applicabilities to the various system of the fuel bed with various solid materials.

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Design Impact evaluation through CFB Boiler Design Parameter and Lower Furnace Fraction of Combustion Heat (순환 유동상 연소로 설계 인자 및 하부 연소율에 따른 설계 영향 평가)

  • Yang, Jongin;Kim, Taehyun;Choi, Sangmin
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.41-42
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    • 2012
  • Circulating fludized bed(CFB) furnace which can use a variety of low-grade fuels because of high heat capacity and good mixing characteristic in its furnace have turned out to be effective system. There is no many research to design CFB boiler in korea. thus, we feel necessity to research design method. So far accurate hydrodynamics and combustion mechanism information in CFB furnace has been lacked. Therefore, design method that derives design parameter is being made. so, this study is aimed to derive design parameters of CFB furnace from heat and mass balance by using existing plant data.

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Detailed Spectroscopic Measurements of Chemiluminescence from Turbulent Premixed Flames in a Dump Combustor

  • Santavicca, D.A.;Lee, Jong-Guen
    • Journal of the Korean Society of Combustion
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    • v.9 no.3
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    • pp.19-26
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    • 2004
  • This paper presents results of experimental study of flame chemiluminescence from turbulent premixed flames in a dump combustor. A detailed spectroscopic measurement of chemiluminescence over the wavelength of 405-495 nm is made for various flow conditions. No effect of turbulence on the relationship between chemiluminescence and heat release is found, suggesting the overall chemiluminescence intensity collected be used as a measure of overall heat release for non-oscillating stable flame. The background-$CO_2^*$ subtracted $CH^*$ chemiluminescence is found to be more sensitive to the equivalence ratio and premixedness of fuel-air mixture than $CO_2^*$ chemiluminescence.

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Prediction of Explosion Limits of Organic Halogenated Hydrocarbons by Using Heat of Combustions (연소열을 이용한 유기할로겐화탄화수소류의 폭발한계의 예측)

  • Ha, Dong-Myeong
    • Fire Science and Engineering
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    • v.26 no.4
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    • pp.63-69
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    • 2012
  • Explosion limit is one of the major combustion properties used to determine the fire and explosion hazards of the flammable substances. In this study, the lower explosion limit (LEL) and upper explosion limit (UEL) of organic halogenated hydrocarbons were predicted by using the heat of combustion and chemical stoichiometric coefficients. The calculated explosion limits by the proposed equations agreed with literature data within a few percent. From the given results, using the proposed methodology, it is possible to predict the explosion limits of the other organic halogenated hydrocarbons.

A Study on the Effects of Ignition Systems on the Heat Release Rate and Mass Fraction Burnt at a Constant Volume Combustion Chamber (정적연소기에서 점화장치가 열발생률과 잘량연소율에 미치는 영향에 관한 연구)

  • Song, Jeong-Hun;Lee, Gi-Hyeong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.11
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    • pp.1486-1496
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    • 2000
  • The initial flame kernel development and flame propagation in a constant volume combustion chamber is analyzed by the heat release rate and the mass fraction burnt. The combustion pressure is measured with a piezoelectric type pressure sensor. In order to evaluate the effects of ignition system and ignition energy on the flame propagation, four different ignition systems are designed and tested, and the ignition energy is varied by the dwell time. Several different spark plugs are also tested and examined to analysis the effects of electrodes on flame kernel development. The results show that the when the dwell time is increased, and when the spark plug gap is extended, heat release rate and the mass burnt fraction are increased. The materials and shapes of electrodes affect the flame development, because they change the energy transfer efficiency from electrical energy to chemical energy. The diameter of electrodes influences not only the heat release rate but also the mass burnt fraction as well.

Heat Recovery Modeling and Exergy Analysis of Dry Combustion Process for Explosive Gas Treatment Using Aspen Plus (아스펜 플러스를 이용한 폭발성 가스 건식 연소 처리공정의 열회수 모델링 및 엑서지 분석)

  • Choi, YongMan;Choi, Changsik;Hong, Bumeui;Cho, Sung Su;Kim, Yong Jin;Kim, Hak Joon
    • Journal of Korean Society for Atmospheric Environment
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    • v.33 no.5
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    • pp.521-528
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    • 2017
  • In the combustion treatment of explosive gases with a high heating value such as $H_2$ and $NH_3$ used in semiconductor and chemical processes, the heat recovery modeling and exergy analysis of the process using the Aspen Plus simulator and its thermodynamic data were performed to examine the recovery of high temperature thermal energy. The heat recovery process was analyzed through this process modeling while the exergy results clearly confirmed that the rigorous reaction mainly occurs in the condenser and the chamber. In addition, the process modeling demonstrated that approximately 95% of the exergy is destructed on the basis of the exergies injected and the exergy being exhausted. Using the exergy technique, which can quantitatively analyze the energy, we could understand the energy flow in the process and confirm that our heat recovery process was efficiently designed.