Calculation and Analysis of Hydrodynamic Characteristics for First 600-MW Supercritical Down-Fired Boiler

In order to check the security and reliability of the water-wall,the hydrodynamic characteristic computation program is adopted with the operating parameters taken as initial values to calculate the flow rate and outlet temperature of the working substance in a 600-MW boiler of one thermal power plant which is the first supercritical down-fired boiler designed and put into operation in the world.The hydrodynamic characteristics in normal and coking conditions are compared.The overall calculation values of the outlet working substance temperature match well with the operation data,which illustrates that the program is suitable for practical application.The results show that the lower-furnace water-walls with low mass-flux optimized rifled tubes exhibit a strong positive flow response while the upper-furnace water-walls with vertical smooth tubes exhibit an evident negative mass flux response.Compared to the normal condition,in the coking conditions the mass velocities of the coking circuits in the lower furnace decrease with the outlet fluid temperatures of all circuits being decreased.