On The Steam Flow Distribution Of Complex System Of Utility Boiler

Overheating tube rupture of superheater and reheater is the most common accident to power-off in utility boiler. Generally, the problem appears in the flue gas side and the steam side. The steam flow imbalance at the steam side is one of major results. The static pressure distribution mathematical models of header system with steam introducing in axes are summarized in this thesis. The numerical simulation was used in this thesis to study the static pressure distribution of header system with steam introducing in radius and the numerical solution was discussed.In order to verify the arithmetic and corresponding program, simulation on the header system with tee-junctions in utility boiler is carried out, and the static pressure distribution and the flow imbalance between panels are obtained. The results indicated that the method in this thesis is reasonable and feasible, and can be more precise in engineering design.The nonuniform QUICK scheme was presented and used in this thesis because the pseudo-diffusion influenced the results in the simulation of the flow field greatly. The obtained results indicated that the pseudo-diffusion was avoided effectively and showed the present method and scheme was feasible.In addition, the obtained results indicated that the vortices existing in tee-junctions zone influenced the static pressure distribution greatly, and caused greater flow imbalance between panels. The size of vortices is related to the structure of headers. At last, the deficiency was pointed out and the improved solution was put forward in this thesis on the basis of theory analysis and numerical computation.