Flow Field Numerical Simulation And Structure Optimization Of Metal Porous Media Gas-Solid Separator

Currently, thermal power accounts for the vast majority of China's energy structure,according to statistics, 15 million tons of soot have been produced every year. So,the development of excellent performance, stable operation of dust removal equipment is imperative. In earlier years, bag filter plays an important role in thermal power plant soot filter owing to its higher filtration efficiency, with the improvement of environmental standards and metal porous filter production technology, the use of metal porous media filter instead of bag filter has become a trend.In this paper, the prototype of the metal porous media dust collector in a coat-fired power plant in Xianyang is taken as the research subject. For the problem of unevenness airflow inside the filter, frequently replace filter sticks which resulting in a significant reduction of equipment stability, however, it is quite difficult to directly text the internal flow field with the latest industrial technology. Fortunately, simulation of filter internal flow field by ANSYS FLUENT 15.0 make it possible. With the fluid simulation software, we can find out the reasons for the above unfavorable factors in filter which is helpful for us to proposed structural optimization indicators and four variant schemes, refer to the modeling results of the modified structure to guide the engineering practice.Numerical simulation of prototype metal porous media filter internal flow field, based on the comparison of the simulated results with the measured data, the following results are obtained: porous jump model is authentic to deal with porous media filter sticks. The nonuniformity of the flow field inside the filter leads to a large change in the flow distribution coefficient of the filter sticks, the maximum flow uneven amplitude of the filter sticks AK is as high as 1.47 and integrated uneven flow amplitude (?) is 0.131,which the edge of the two filter sticks flow distribution coefficient is larger. The large nonuniformity of the flow distribution coefficient increases the filter internal pressure and increases the frequency of the replacement or cleaning of the filter sticks, which is extremely detrimental to the stable operation of filter.Aiming at the problem of the airflow organization of the prototype filter, the four kinds of optimization and deformation structures are simulated by changing the length of the filter sticks and the height of the inlet, the number and layout of the filter sticks, the angle and the number of the inlet and the different permeability coefficient of that filter sticks, the simulated results show that the "best structure" of the four variant structures are filter sticks length L = 0.72m,inlet height T = 0.288m; remove the first and second column filter sticks; set double inlet,90°+270° distribution; reduce 4 to 8 columns, 4 to 6 row filter sticks permeability coefficient to 7x10-13m2. The "best structure" of the above four kinds of modified structures has better optimization effect on the parameters of airflow uniformity - the maximum flow uneven amplitude, the integrated flow uneven anplitude and the airflow uniformity index. Take maximum flow uneven amplitude (?) for example, The 'best structure" of the above four variants is reduced to 63.27%,17% 51.11%?9.09% compared with "prototype".