• 제목/요약/키워드: 3-D combustion model

검색결과 93건 처리시간 0.029초

Development of an Entrainment Model for the Steam Line Break Mass and Energy Release Analysis

  • Park, Young-Chan;Kim, Yoo
    • 에너지공학
    • /
    • 제12권2호
    • /
    • pp.101-108
    • /
    • 2003
  • The purpose of this study is to develop an entrainment model of the Pressurized Water Reactor (PWR) U-tube Steam Generator (SG) for Main Steam Line Break (MSLB) analyses. Generally, the temperature of the inside containment vessel at MSLB is decreased by introducing the liquid entrainment effect. This effect makes a profit on the aspect of integrity evaluation for Equipment Environmental Qualification (EEQ) in the containment. However, the target plant, Kori unit 1 does not have the entrainment data. Therefore, this study has been performed. RETRAN-3D and LOFTRAN computer programs are used for the model development. There are several parameters that are used for the initial benchmark, such as Combustion Engineerings (CE) experimental data and the RETRAN-3D model which describes the test leg. A sensitivity study is then performed with this model in which the model parameters are varied until the calculated results provide reasonable agreement with the measured results for the entire test set. Finally, a multiplication factor has been obtained from the 95/95 values of the calculated (best-estimate) quality data relative to the measured quality data. With this new methodology, an additional temperature margin of about 40$^{\circ}C$ can be obtained. So, the new methodology is found to have an explicit advantage to EQ analyses.

대전 4공단 소각로 후연소로 모델 연구 (Numerical Study of the Post Combustion Chamber of Grate Type Incinerator in Daejon 4th Industrial Complex)

  • 김혜숙;신미수;장동순;박병수;엄태인
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2002년도 추계 학술대회논문집
    • /
    • pp.133-138
    • /
    • 2002
  • A 3-D axisymmetric computer program is developed to predict the NO behavior in SNCR system for the stoker incinerator with the waste treatment capacity, 200ton/day. To this end a turbulent reacting flow field calculation is made using proper assumption and empiricism. The stoker bed is assumed to be a homogeneous waste-volatilized gaseous state. The initial composition or reactants are assumed based on the data of the ultimate analysis. Turbulent is resolved by k-e model and turbulent reaction is handled by eddy-breakup model harmonized with empirical chemistry data for gaseous combustion, NO and urea reaction. The liquid droplet is traced by Lagrangian method incorporated by aerodynamic drag, Coriolis and crntrifugal forces. Radiation is treated by sensible heat loss model. Calculation results are in good agreement with experimental data at the outlet of post combustion chamber in Daejon 4th industrial complex. The flue gas shows the temperature range of $900\sim1000^{\circ}C$, velocity of 5m/s and NO concentration of 140ppm at the exit while the measured temperature, flue gas velocity and NO concentration are $967^{\circ}C$, $3\sim4m/s$ and $100\sim200ppm$respectively. Using the developed computer program a parametric study has been made with the variation of heat content of waste, castable length and SNCR variables for the determination of proper injector location. In general, the calculated results are consistent and physically acceptable.

  • PDF

YAlO3:Tbx3+에서 발광소멸 곡선을 이용한 에너지 전달에 관한 연구 (A Study on the Energy Transfer of YAlO3:Tbx3+ using Decay Curves)

  • 김광철;최진수
    • 반도체디스플레이기술학회지
    • /
    • 제14권1호
    • /
    • pp.13-17
    • /
    • 2015
  • $YAlO_3:Tb{_x}^{3+}$ has been synthesized by a combustion process and the concentration x of Tb was varied from 0.001 and 0.05 mol% per mole of YAlO3. The energy transfer of $^5D_3{\rightarrow}^7F_6$(385nm) and $^5D_4{\rightarrow}^7F_5$(544nm) transitions on the $YAlO_3:Tb{_x}^{3+}$(x =0.001, 0.05) have been investigated by using decay curves. The energy transfer mechanism was explained by Inokuti and Hirayama model. The results of calculation and fitting showed that values of n are 6.11(x=0.01) and 6.13(x=0.005). These indicate that the energy transfer mechanism between $Tb^{3+}$ ions is dipole-dipole interaction.

1D 시뮬레이션 기반 GDI 인젝터의 비선형적 분사 특성 해석에 대한 연구 (Investigation on the Non-linear Injection Characteristics of GDI injector using 1D Simulation)

  • 이진우;문석수;허동한;강진석
    • 한국분무공학회지
    • /
    • 제28권4호
    • /
    • pp.169-175
    • /
    • 2023
  • Multi-injection scheme is being applied to GDI combustion to reduce PM and PN emission to meet the EU7 regulation. However, very short injection duration encounters the ballistic injection region, which injection quantity does not increase linearly with injection duration when applying multi-injection. In this study, numerical studies were conducted to reveal the cause of ballistic injection and the effect of design parameters on ballistic region using 1-D simulation, AMESim. Injection rate and injection quantity were compared with experiment to validate the established model, which showed the accuracy with 10% error. The model revealed that the tendency of ballistic region coincides with the needle motion behavior, which means that parameters at the upper part of needle such as electro-magnetic force, needle spring force and needle friction force have dominant effect on ballistic injection. To figure out the effect of electro-magnetic and needle friction force on ballistic, those parameters were varied to plus and minus 10% with model. The result showed that those parameters clearly changed the ballistic region characteristics, however, the impact became insignificant for outside of ballistic region, which means that the ballistic injection is mainly influenced by initial motion of injector needle.

3D-IR Matrix 버너 개질기를 활용한 모사 바이오가스 수증기 개질 연구 (The Study of Steam Reforming for Model Bioigas using 3D-IR Matrix Burner Reformer)

  • 임문섭;전영남
    • 한국수소및신에너지학회논문집
    • /
    • 제22권1호
    • /
    • pp.100-108
    • /
    • 2011
  • The use of biogas as an energy source reduces the chance of possible emission of two greenhouse gases, $CH_4$ and $CO_2$, into the atmosphere at the same time. Its nature of being a reproducible energy source makes its use even more attractive. This research if for the hydrogen production through the steam reforming of the biogas. The biogas utilized 3D-IR matrix burner in which the surface combustion is applied. The nickel catalyst was used inside a reformer. Parametric screening studies were achieved as Steam/Carbon ratio, biogas component ratio, Space velocity and Reformer temperature. When the condition of Steam/Carbon ratio, $CH_4/CO_2$ ratio, Space velocity and Refomer temperature were 3.25, 60%:40%, 19.32L/$g{\cdot}hr$ and $700^{\circ}C$ respectively, the hydrogen concentration and methane conversion rate were showed maximum values. Under the condition mentioned above, $H_2$ concentration was 73.9% and methane conversion rate was 98.9%.

Experimental and Kinetic Studies of Esterification of Glycerol Using Combustion Synthesized SO42-/CeO2-Al2O3

  • Veluturla, Sravanthi;Narula, Archna;Rao, D. Subba;Indraja., S;Kulkarni, Rajeswari. M.
    • Korean Chemical Engineering Research
    • /
    • 제56권4호
    • /
    • pp.592-599
    • /
    • 2018
  • An increase in the global production of biodiesel has resulted in the newfound significance of its byproduct, glycerol. The synthesis of acetins is an economical avenue to enhance the value of glycerol derived from biodiesel. WE developed an eco-friendly process for the synthesis of fuel additives from glycerol using a mixed oxide $SO{_4}^{2-}/CeO_2-Al_2O_3$ as catalyst. The $CeO_2-Al_2O_3$ mixed oxide was synthesized by the combustion method and then sulfated. The characterization of the catalyst was by means of XRD, BET, FTIR, and SEM. The influence of temperature, mole ratio and catalyst loading on yield and selectivity of the acetins was studied for the esterification of glycerol. The reaction rate constants ($k_1$, $k_2$ and $k_3$) were estimated using optimization method in MAT lab, and the activation energies ($E_1$, $E_2$ and $E_3$) were determined by the Arrhenius equation. Furthermore, a kinetic model was developed.

모델연소기 선회유동장에서의 속도 및 분무특성 (Velocity and Spray Characteristics under Swirl Flows in a Model Combustor)

  • 배충식;이동훈
    • 한국분무공학회지
    • /
    • 제3권2호
    • /
    • pp.42-50
    • /
    • 1998
  • The effect of swirl flows un the fuel spray characteristics were investigated for various swillers in a model combustor. The interaction between the flow field and fuel spray in the main combustion tone made by frontal devices including fuel injection nozzles and swirlers. which were characterized by flow velocities, fuel droplet sizes and their distributions which were measured by APV(Adaptive Phase/Doppler Velocimetry) under atmospheric condition at 320cc/min kerosine fuel flow and 0.04kg/sec air supply. A dual swirler with circumferential two-stage swirl vanes of $40^{\circ}\;and\;45^{\circ}$ vanes in different directions and two single-stage swillers of $40^{\circ}$ vanes with 12 and 16 vanes were tested. It was found that the dual swirler has the largest recirculating zone with highest reverse flow velocity. The strongest swirl flow was found at the boundary of recirculation zone. Small fuel droplets were observed in the main axial stream and inside the recirculation zone when swirling flow field were generated by the frontal devices. These findings could give the tips on the optimal design of frontal devices to realize low emissions in gas turbine combustion.

  • PDF

석탄화염내 화학반응에 관한 연구 (Chemical Reactions in the Coal-Methane-Air Flame)

  • 박호영;안달홍;김종진
    • 에너지공학
    • /
    • 제11권2호
    • /
    • pp.166-177
    • /
    • 2002
  • 본 연구는 화염안정을 위해 약간의 메탄을 첨가한 1차원, Hat, 예혼합, 층류 석탄-공기 화염구조에 관한 연구로서 반응영역을 늘리기 위해 0.3 atm에서 운전되는 저압버너를 사용하였다. 본 연구에서는 가스 온도, 주요가스의 농도, 샘플된 촤의 분석과 화염속도에 대하여 여러 모델들의 해석결과를 실험결과와 서로 비교하였다. 여러 모델중 촤 표면적 지수(S=4)와 휘발성분에 대해 각각의 탈휘발화 속도상수를 적용한 model II $I^{*}$ -d가 실험치와 비교적 일치함을 보여주었다. 샘플된 촤의 분석 결과 입자의 반응이 낮게 예측되어져 촤 표면적지수를 증가시켜야만 했다. 이 지수는 촤의 반응 표면적에 대한 민감도 분석으로부터 얻어진 결과였고 model II $I^{*}$ -d의 화염속도 해석결과는 대부분의 측정치에 근접한 결과를 보여주고 있다. 고체 입자 직경은 열적 지연과 반응표면적을 통하여 탈휘발화율과 촤 산화에 큰 영향을 주며 이는 곧 화염속도에 영향을 주고 있음을 보여주었다.

환형 연소기 시스템에서 비연소 3D 음향장 해석 (3D Acoustic Field Analysis in an Annular Combustor System under a Cold Flow Condition)

  • 임재영;김대식
    • 한국추진공학회지
    • /
    • 제21권6호
    • /
    • pp.49-56
    • /
    • 2017
  • 본 연구에서는 환형 시스템에서 열음향 문제를 모델링하기 위하여 자체 3D 유한요소해석을 모델 개발을 통하여 음향장을 해석하였고, 다양한 음향 모드를 벤치마크 연소기의 실험 결과와 비교/검증하였다. 비교 결과, 본 해석에서 사용된 음향장 해석 코드는 환형 시스템에서 실험으로 계측된 다양한 음향모드들을 예측하는데 성공하였다. 또한 연소실의 횡방향 모드는 노즐의 음향 경계 조건의 영향을 크게 받게 되고, 노즐에서의 압력 분포 역시 연소실의 압력장과 밀접한 관련이 있는 것으로 나타났다.

분사율 형상에 따른 디젤분사계의 분무거동에 관한 시뮬레이션 (Simulation of Spray Behaviors by Injection Rate Shapes in Diesel Injection System)

  • 왕우경;장세호;고대권;안수길
    • 동력기계공학회지
    • /
    • 제3권3호
    • /
    • pp.36-43
    • /
    • 1999
  • Many of thermodynamic-based diesel combustion simulations incorporated a model of fuel spray which attempts to describe how the spray develops according to time. Because the spray geometry is an essential aspect of the fuel-air mixing process, it is necessary to be calculated quantitatively for the purpose of heat release and emission analysis. In this paper, we proposed the calculating method of non-evaporation spray behaviors by injection rate shapes under actual operating conditions of diesel engine. We confirmed the utility of this calculating model as the calculated results were compared with the measured results. This calculating program can be applied usefully to study on the diesel spray behavior.

  • PDF