Study On Designing And Optimizing Of Gas-Flow Distribution Of Fabric Bag Filters In Large-Scale Coal-Fired Power Plant

With the rapid development of economy and industry, the problems of energy consumption and environmental pollution are becoming more and more serious in China during the last decades. Coal-fired power plant holds an important position in the electric power industry, which is determined by China's energy structure, causing the air pollution due to coal combustion turning into one of the most serious pollution forms. Therefore, studying and applying high-efficiency ash-removal technology makes great sense to the development of economy and society.The environmental protection requirement of our country is getting increasingly stricter, which makes meeting the emission standard for the tranditional electric precipitators is harder and harder. Then the fabric bag filters, which have higher ash-removal efficiency, gradually expand its occupancy in coal-fired power plants, and have already gained some successful application experiences.But there are still some problems which should not be ignored with the development and application of fabric bag filters, including the system resistance is high, the service life of bags is short, bags changed quite often and so on, and the gas flow distribution being nonuniform is one of the major reasons causing all these problems.The fluxion in fabirc bag filters is very complicated, so designers always pose the gas flow distribution proposal based on experience datas or results from simple models, which is not objective enough, resulting the gas flow distribution effect can not meet the expectation value.In consideration of the situation, in order to provide necessary basis for the gas flow distribution proposal designing and optimizing, a filtration chamber on the side edge which directly connected to an elbow of a fabric bag filter project in a 300MW coal-fired power plant was set as research object, scaled physical model and numerical simulation model was established according to the similarity theory to test and optimize the gas-flow distribution under different diversion measures, and an optimum proposal was obtained. After the gas flow distribution proposal was put into use on the fabric bag filter project, a serie of tests were carried out to test the effect of it, the results showed that the gas flow distribution of fabric bag filter's inlet section and different cells of the fitration chamber was uniform enough, meeting the disigning standard.In this study, the research process combined scaled physical model test, numerical simulation, and test on-site, through which a kind of research method applicable for the gas flow distribution of fabric bag filters was obtained. The research conclusion provided basis for the gas flow distribution proposal designing and optimizing of fabric bag filter project in large-scale coal-fired power plant, which could make sense to similar project or study aftertime.