Design And Implementation Of Low Nitrogen Combustion Technology For Biomass Bed Combustion Boiler

Because biomass energy has the characteristics of renewability large amount of resources,good environmental protection effect,wide distribution of kinds,easy utilization,and so on,it has been widely used to gradually replace coal or oil.However,the problem of nitrogen oxides produced by combustion can not be ignored.In order to reduce the emission of nitrogen oxides produced by biomass combustion in stratified combustion boiler,this paper designs a technical scheme of low nitrogen biomass combustion based on coal-fired bed combustion boiler,and the scheme can be applied to the practical boiler engineering.In this paper,a kind of 6 ton coal-fired laminated boiler is selected to transform biomass to low nitrogen combustion,and the corn bar compression block is used as fuel to carry out numerical calculation.A fast calculation method for prediction of nitrogen oxide generation in the furnace of biomass bed combustion boiler is designed.The calculation method is simpler and faster than the conventional calculation model,and the accuracy of calculation can be guaranteed.Then the biomass combustion in stratified combustion boiler before the boiler transformation was measured experimentally and calculated by numerical simulation.The calculated results were corrected according to the actual measurement results,and the results were compared progressively with the actual measurement results.Then the boiler is reformed once,the secondary air is added into the boiler throat area,and the result of simulation calculation is compared with the result of actual measurement,which also verifies the accuracy of the calculation result.Then,the secondary air in the furnace throat area is replaced by the tertiary air of the low temperature flue gas,so as to reduce the emission of nitrogen oxides.The numerical simulation of the scheme is carried out,and the results are compared with the results before the transformation.The next step will be to optimize the low-nitrogen combustion technology.The effect of flue gas temperature on the formation of nitrogen oxides is studied firstly,and the technical scheme of low nitrogen combustion is optimized according to the results obtained.Then the combustion technology scheme is optimized again,and two rows of secondary air nozzles are installed in the furnace burnout area,which can not only ensure the burnout of the combustible gas in the flue gas in the furnace burning area,but also control the production of NOx.Finally,the optimized design scheme is applied to the practical transformation,so that the low nitrogen combustion technology of biomass bed combustion boiler can be implemented and compared with the results of calculation after the revamping,and the model is further improved,and the following retrofit scheme is put forward.The modified boiler can ensure combustion efficiency and reduce nitrogen oxide emission effectively.It is of great significance to environmental protection and energy utilization,so it has a broad application prospect.