Prediction of Radiative Heat Transfer in Industrial Equipment Using the Radiation Element Method

2001 ◽  
Vol 123 (4) ◽  
pp. 530-536 ◽  
Author(s):  
Zhixiong Guo ◽  
Shigenao Maruyama

The radiation element method by ray emission method, REM2, has been formulated to predict radiative heat transfer in three-dimensional arbitrary participating media with nongray and anisotropically scattering properties surrounded by opaque surfaces. To validate the method, benchmark comparisons were conducted against the existing several radiation methods in a rectangular three-dimensional media composed of a gas mixture of carbon dioxide and nitrogen and suspended carbon particles. Good agreements between the present method and the Monte Carlo method were found with several particle density variations, in which participating media of optical thin, medium, and thick were included. As a numerical example, the present method is applied to predict radiative heat transfer in a boiler model with nonisothermal combustion gas and carbon particles and diffuse surface wall. Elsasser narrow-band model as well as exponential wide-band model is adopted to consider the spectral character of CO2 and H2O gases. The distributions of heat flux and heat flux divergence in the boiler furnace are obtained. The difference of results between narrow-band and wide-band models is discussed. The effects of gas model, particle density, and anisotropic scattering are scrutinized.

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Hanene Belhaj Ali ◽  
Hajer Grissa ◽  
Faouzi Askri ◽  
Sassi Ben Nasrallah

In this paper, the control volume finite element method (CVFEM) is coupled with the weighted sum of gray gases model (WSGGM) to study the radiative heat transfer in a nongray medium. To the best of our knowledge, the CVFEM–WSGGM is applied for the first time to simulate real-gas. The accuracy of the proposed method is tested through one- and two-dimensional radiative heat transfer within an enclosure filled with a single composition (water vapor or carbon dioxide) or a mixture of H2O, CO2, and N2. Compared to the discrete ordinates method (DOM)–statistical narrow band model (SNBM), the proposed method, using the WSGG model parameters due to Smith or Farag, yields much accurate results than the zonal method (ZM)–WSGGM and DOM–WSGGM. In addition, the present method needs very less control volumes and angles, and consequently computational time, compared to the DOM and ZM coupled with WSGGM.


2005 ◽  
Author(s):  
Youssef Joumani ◽  
Guillaume Mougin ◽  
Fouad Ammouri ◽  
Marc Till

Air Liquide has been involved in the design of industrial furnaces (glass melting, reheating, aluminum, …) for several years. Thanks to that experience, known-how and expertise in modeling such applications have been developed. Dedicated simulation tools — 0D for global heat and mass balance, 1D for the prediction of longitudinal temperature profiles and 3D for detailed analysis — have been built. Each of them is very helpful when used relevantly and offers numerous opportunities at each step of the design of a furnace. In such kind of applications, the temperature levels are very high (up to 2500 K). As a consequence it is very crucial to simulate the radiative heat transfer as accurately as possible. This requires the use of a radiation model that can take into account complex geometries, non-isothermal media and various gas mixture compositions. Very often, three-dimensional simulations are necessary and reduction to smaller dimension problems is difficult or inadequate. The present paper introduces a new radiation model for computing two-dimensionally radiative heat transfer in an industrial furnace with a piecewise distributed load. To reduce the three-dimensional problem to two dimensions, the method consists in coupling the 2D radiation transport equation to a boundary condition based on view factors through an imaginary plane to homogenize the radiative behavior of the load surface. A solution procedure using the discrete transfer method associated to a weighted-sum-of-gray-gases database to deal with absorption and emission of a CO2-H2O mixture is proposed. Simulation results are finally compared to an analytical formula and then to a full-3D approach taking into account participating media, non-isothermal and gray walls. All tests show that this model can be used to simulate industrial configurations with a good accuracy.


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