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investigated the oxy-coal fired CFB power plant, which includes CFB combustion unit, ASU, CPU, power island, and heat exchangers. Oxy-fuel combustion had a 4% lower overall exergy efficiency than air-fired combustion. They found that the air heater's exergy efficiency was 10.3% higher in oxy-fuel conditions than those in conventional conditions. The turbine and FWH models destroyed 9.01% of the total fuel exergy, with the turbines accounting for roughly half of that. They reported the combustion process as a major contributor to exergy destruction (around 60%). The oxy-fuel combustion process had a 4% improved combustion efficiency. The exergy efficiencies of the two boiler models were found to differ significantly. Boilers, turbines, FWHs, ASU, and CPU units were used to split the entire combustion system. evaluated the findings of two boiler models in an exergy analysis of 600 MW conventional air and oxy-fuel power plants. Since the dependence on temperature is weaker if compared to the previous transport properties, the fitting procedure is typically applied directly on the temperature, rather than on its logarithm.

The thermal diffusion ratios are estimated using the simplified procedure described in Ref. (6) refers at pressure of 1 bar and therefore the real evaluation of a binary diffusion coefficient Γ i, j at pressure p is given by Γ i, j = Γ i, j 0 p, where p is the pressure in bar. Moreover, while the viscosities and conductivities of species do not depend on the pressure, the binary diffusion coefficients inversely depend on pressure. Obviously, the fitting procedure has to be carried out for the particular gaseous mixture under investigation, which means that the fitting cannot be done “once and for all,” but it must be carried out once at the beginning of each new problem. Third-order polynomial fits (i.e., N = 4), as suggested in Ref. The b i,k η, b i,k λ, b i,j,k Γ coefficients are the fitting parameters for viscosity, thermal conductivity, and mass diffusion, respectively. Γ i, j 0 is the binary mass diffusion coefficient between ith and jth species evaluated at 1 bar. Where η i and λ i are the dynamic viscosity and the thermal conductivity of ith species, respectively. (6) ln Γ i, j 0 = ∑ k = 1 N b i, j, k Γ ln T k − 1