| The uniformity of primary air flow and coal powder flow between each pulverizedcoal pipeline in the directed-fired system has a great influence on the combustion ofboiler. Good uniformity can not only ensure the uniformity and stability of thecombustion, significantly reducing the probability of coking, overtemperature tubeburstof heating surface and other accidents, but also optimize the distribution of oxygen infurnace, reducing the generation of NOx and other harmful gases. In this paper, apulverized coal distributor is designed to improve the uniformity of air and coal powderin Y-shape branch pipe of directed-fired system, and the main content is to analysis theflow characteristics of two-phase flow in the distributor by using CFD software fornumerical simulation analysis, which verifies its theoretical feasibility.Firstly, study the flow characteristics and numerical simulation methods oftwo-phase flow. And determine the description method and all the numerical models oftwo-phase flow in Y-shape branch pipe, which ensure the accuracy of the numericalsimulation. Secondly, design the pulverized coal distributor in which a pair of adjustabledampers is the major adjustment method. Through the orthogonal analysis method, themain factors and the curves of the regulating performance are both determined. Thirdly,obtain the deviation of air and powder under different resistance at the outlet of thebranch pipe. And take a certain condition as an example, do the dynamic adjustment testwith the regulating characteristics curves of distributor. Finally, optimize the structure ofdistributor according to the test results and verify the improved performance through thestatic and dynamic simulation test.The parameters of the simulation test results show that the designed and improveddistributor can significantly increase uniformity of primary air flow and coal powderflow between the two outlets of Y-shape branch pipe, which has important engineeringsignificance. |
PDF Full Text Request