Abstract
The purpose of this paper is to present the flow field in the 300MW tangential firing utility boiler that used the Low NOx Concentric Firing System…LNCFS. Using the method of cold isothermal simulation ensures the geometric and boundary condition similarity. At the same time the condition of self-modeling is met. The experimental results show that the mixture of primary air and secondary air becomes slower, the average turbulence magnitude of the main combustion zone becomes less and relative diameter of the tangential firing enlarges when the secondary air deflection angle increase ; when the velocity pressure ratio of the secondary air to the primary air (P_2/P_1) enlarges, the mixture of the secondary air and the primary air becomes stronger, the average turbulence magnitude of the main combustion zone increases, the relative diameter of the tangential firing becomes larger, because the OFA laid out near the wall has a powerful penetration, the relative diameter of the tangential firing on the section of the OFA to the primary air (P_<OFA>/P_1) increases, the relative diameter of the tangential firing on the section of the OFA grows little, the average turbulence magnitude becomes larger, the penetration of the OFA becomes more powerful.
