Numerical Simulation And Structure Optimization Of A Combined Liquid-Solid Distributor

Because of the non-homogeneity of particle distribution in the pipe bundle, which results in process instability and great energy consumption, the development of fluidized bed heat exchanger in industry field is restricted. A new type of distributor,a combined distributor, which is based on theories of branched pipe line and fluidization and combined with the pre-distributor and the main distributor is suitable to solve the problem.The distributor is using the baffle and perforated plate as pre-distributor and the concentric tube as the main distributor,concentric tubes are fixed on the inlet of heat exchanger pipes. An Eulerian mutiphase model incorporating the kinetic theory for solid particles was applied in order to simulate the liquid-solid two-phase flow.The optimized structure parameter values are finded by the numerical simulation method.First in two dimension simplified structure,the volume fraction of solids as well as its unevenness in lower vessel in different pre-distributor structure,the average volume fraction of solids as well as its unevenness in different main-distributor in heat-exchanger pipe are simulated by CFD method.Then comparing the multipoint total pressure in the wall and the particulate fluidization zone in lower vessel which are measured in the two dirmentional medium-type experimental equipment and the simulative results so that to make sure the applicability of the model.Comparing the unevenness of the volume of solids so as to find the best structure of all.Then based on the two dimension numerical simulational results, the volume of solids and its unevenness in the lower vessel as well as the heat-exchanger pipe was simulated in three dimensional structure.The volume proportion between the main-distributor and the lower vessel as well as the style of the hole distributing was considered.so the three dimentional structure numerical simulational results was not only used to optimized the main-distributor structure ,but also find the distributing effect of the style of the hole distributing. So that supply the experimental research with theory basic.