Research On Effect Of Low Nitrogen Burner On Boiler Performance

China since the policy of reform and opening to the outside world, electric power industry is developing rapidly, has become the power installed machine capacity and annual power generation capacity ranks the world second power production and consumption power. At the same time it brings huge environmental pollution. Nitrogen oxides, as one of the major pollutants in the atmosphere, although have a wide range of sources, and showing a diversified development trend, but thermal power plant has been the maximum nitrogen oxide production source. How to reduce the emissions of nitrogen oxides, has become an urgent environmental issues.Horizontal bias separated type combustion technology as an efficient and clean combustion technology has a lot of advantages to reduce nitrogen oxide emissions, steady low load combustion, prevent furnace slagging, but a disadvantange of incomplete combustion at the same time. It has become a problem to which for the field staff to pay close attention that how to guarantee boiler efficiency and reduce NO_x emissions as far as possible at the same time. As the research object, a 670t/h pulverized coal boiler in a power plant was researched. Numerical caiculation of flow and combustion characteristics, NO_x generation and mechanical incomplete combustion heat loss inside the furnace after the horizontal bias burner transformation was carried out.In this dissertation, the Gambit software was used to establish the physical model of the boiler, and Fluent to set up a reasonable mathematical model of that and set the corresponding boundary conditions. This dissertation set up a total of two reconstruction schemes, three different load levels and twelve pulverized coal bias ratio. The furnace internal velocity field, temperature field, the NO_x emissions and mechanical incomplete combustion heat loss etc. was calculated. The analysis shows that, after the reconstruction, the phenomenon of flame eroding the wall is improved, and the distribution of temperature field is more reasonable. With the value of pulverized coal bias ratio increases, NO_x emissions at the furnace outlet decrease gradually while mechanical incomplete combustion heat loss increases. Both of them show the opposite trend, therefore, it is necessary to ascertain a reasonable value of bias ratio. After analysis, the reasonable value of bias ratio is 6.