Numerical Simulation Research Of Air Channel Flow Process In Thermal Power Station

Air system is not only an important part of thermal power plant,but also a major source of auxiliary power.The optimization of structural design for air channel can reduce the flow resistance and energy consumption.For thermal power plants,it is an important way to decrease the auxiliary power ratio.The author has been engaged in power plant design work for more than 20 years,and is very familiar with thermal power plant flue gas system.During heavy design and management work,the author read for the graduate equivalent doctorate,focusing on boiler flue gas system resistance reduction and optimization problem.In this thesis,the numerical method is used to investigate the air channel flow and compute the flow resistance.Based on the computational results,the optimization of channel design is provided.The thesis describes the detailed process for the internal flow field simulation using the commercial software.Before investigation of channel flow for the real thermal power plant,the same process is carried out to simulate the backward facing step flow and NACA0015 airfoil flow.Computational results are compared with experiments.This can be a verification of the mathematical model and the calculation process;On the other hand,discussions and analyses of these simple problems can contribute a better understanding of vortex flow phenomenon,which will be a good foundation for further analysis of the complicated flow problems in channel.The flow in the first kind straight pipe and bend of thermal power plant is investigated numerically,focusing on two types of standards.The uniformity of outlet velocity field distribution,the pressure drop and flow resistance is calculated and analyzed.Based on these results,the influence of structure design on the flow resistance,flow uniformity and ash formation is discussed,as well as the impact of guide plate to the flow in bend.Considering construction land saving and flow uniformity,the second kind duct design is discussed as well.Flow resistance and uniformity of different streamline designs are compared with those of first kind design,with optimization effects of second kind duct to thermal power plant discussed.At the end of the thesis,to further optimize the internal support structure of duct,the application of new internal support structure design in the duct is studied.Based on the numerical simulation results,the influence of different design and connection of new internal support structure is discussed.Finally,the economy and feasibility of new internal support design are discussed in domestic typical 600 MW power plant.It is proposed that the research results of this paper should be carried out into practical engineering application and get promoted.