Study On The Radiation Properties Of Nonisothermal Or Nonhomogeneous Media In One Dimensional Oxy-fuel System

Thermal radiation dominate the energy transfer in furnaces. Accurate calculation theradiation properties of gas, soot and particle is very important for simulation radiative heattransfer in furnace.Oxy-combustion carbon capture technology in investment costs,operating costs, CO2capture costs, large scale and compatibility with existing technologies,has great advantages. Oxy fuel combustion air and flue gas composition routine is verydifferent, so that under the existing air combustion gas radiative properties model is nolonger applicable. Oxy-combustion results in a different flue gas composition asair-combustion. Gas radiation models for air combustion are out of their validity range.Combining SLW, FSK and WSGG model, this paper presents a method, which basedspectral absorption coefficient, to modify WSGG model. New coeffcients for WSGGmodel are proposed based on the up-to-date HITEMP2010database. Soot and coal particles,whose radiation properties change with burnout rate and size, are treated as a singleeffective gas. According to the principle of modified WSGG model, the WSGG modelcorrelations of soot and coal particles are ftted.Compared with existing model in one-dimensional cases, modified WSGG model ofthis paper to simulate radiation heat transfer in nonisothermal/nonhomogeneous flue gashas obvious advantages; compared radiative heat transfer between Oxy-combustion and aircombustion, it is found that oxyfuel promote radiation heat transfer; modified WSGGmodel of this paper in air combustion also achieve high accuracy, so the proposed modelcan be applied to air and oxyfuel.This paper also study the radiative heat transfer of soot and coal particles. WSGG1arebased on fitting emissivity. Compared with WSGG1and Planck mean, we can seeWSGG model can simulate the radiation heat transfer of soot and particles well, andPlanck mean also have a very high accuracy. WSGG1model have large deviations withbenchmark LBL solutions in nonisothermal conditions of soot, also further prove modifiedWSGG model of this paper is correct.In nonisothermal conditions of gas, soot and coal particles mixture, the results showthat, even if volume fraction of soot, coal particles are very small, radiation heat transfercan be greatly enhanced.