scholarly journals Influence of turbulence-radiation interaction on the radiative heat transfer to the wall of large-scale industrial furnaces and temperature distribution in the furnaces

2017 ◽  
Vol 83 (852) ◽  
pp. 17-00041-17-00041 ◽  
Author(s):  
Seiichi TAKEUCHI ◽  
Tatsuyuki OKAMOTO
Author(s):  
Hong Yin ◽  
Mingfei Li ◽  
Zhongran Chi ◽  
Jing Ren ◽  
Hongde Jiang

As the advanced heavy-duty gas turbine develops, the turbine inlet temperature and pressure have increased quite significantly to achieve better performance. The flow and heat transfer conditions of hot components including combustor and turbine become even more extreme than ever which need corresponding aerodynamic and cooling design development. The issue of combustor-turbine interaction has been proposed as a complicated research topic. Currently the hot streak, turbulence intensity, swirling flow, radiation are the four important factors for combustor-turbine interaction research according to the literature. Especially as the turbine inlet temperature increases, the radiative heat transfer plays a more and more important role. In this paper, a first stage vane is selected for the conjugate heat transfer simulation including radiative heat transfer since it is almost impossible to identify the radiative effect in experiment. The goal is to examine the effects of radiative heat flux and temperature increment caused by radiation. Several radiative factors including the inlet radiation, gas composition, vane surface emissivity and outlet reflection are investigated. The temperature distribution and heat flux enhancement under different conditions are compared, which can provide reference to the turbine heat transfer design. The general information of radiative effect can be summarized by quantitative analysis. Results show that the temperature increases obviously when considering the radiation effect as expected. However, these factors show distinct influence on the vane temperature distribution. The inlet radiation has significant impact on the vane leading edge and pressure side. Besides the gas radiation plays quite uniform on the whole vane surface.


Author(s):  
J. D. J. VanderSteen ◽  
J. G. Pharoah

Solid oxide fuel cell (SOFC) technology has been shown to be viable, but its profitability has not yet been seen. To achieve a high net efficiency at a low net cost, a detailed understanding of the transport processes both inside and outside of the SOFC stack is required. Of particular significance is an accurate determination of the temperature distribution because material properties, chemical kinetics and transport properties depend heavily on the temperature. Effective utilization of the heat can lead to a substantial increase in overall system efficiency and decrease in operating cost. Despite the extreme importance in accurately predicting temperature, the majority of SOFC modeling work ignores radiative heat transfer. SOFCs operate at temperatures around or above 1200 K, where radiation effects can be significant. In order to correctly predict the radiation heat transfer, participating gases must also be included. Water vapour and carbon dioxide can absorb, emit, and scatter radiation, and are present at the anode in high concentrations. This paper presents a thermal transport model for analyzing heat transfer and improving thermal management within planar SOFCs. The model was implemented using a commercial computational fluid dynamic (CFD) code and includes conduction, convection, and radiation in a participating media. It is clear from this study that radiation must be considered when modelling solid oxide fuel cells. The effect of participating media radiation was shown to be minimal in this geometry, but it is likely to be more important in tubular geometries.


2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3663-3672
Author(s):  
Filip Juric ◽  
Milan Vujanovic ◽  
Marija Zivic ◽  
Mario Holik ◽  
Xuebin Wang ◽  
...  

Combustion systems will continue to share a portion in energy sectors along the cur-rent energy transition, and therefore the attention is still given to the further improvements of their energy efficiency. Modern research and development processes of combustion systems are improbable without the usage of predictive numerical tools such as CFD. The radiative heat transfer in participating media is modelled in this work with discrete transfer radiative method (DTRM) and discrete ordinates method (DOM) by finite volume discretisation, in order to predict heat transfer inside combustion chamber accurately. The DTRM trace the rays in different directions from each face of the generated mesh. At the same time, DOM is described with the angle discretisation, where for each spatial angle the radiative transport equation needs to be solved. In combination with the steady combustion model in AVL FIRE? CFD code, both models are applied for computation of temperature distribution in a real oil-fired industrial furnace for which the experimental results are available. For calculation of the absorption coefficient in both models weighted sum of grey gasses model is used. The focus of this work is to estimate radiative heat transfer with DTRM and DOM models and to validate obtained results against experimental data and calculations without radiative heat transfer, where approximately 25% higher temperatures are achieved. The validation results showed good agreement with the experimental data with a better prediction of the DOM model in the temperature trend near the furnace outlet. Both radiation modelling approaches show capability for the computation of radiative heat transfer in participating media on a complex validation case of the combustion process in oil-fired furnace.


2019 ◽  
Vol 27 (16) ◽  
pp. A953 ◽  
Author(s):  
Ming-Jian He ◽  
Hong Qi ◽  
Yi-Fei Wang ◽  
Ya-Tao Ren ◽  
Wei-Hua Cai ◽  
...  

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