| In recent years,the circulating fluidized bed boiler（hereinafter to as CFB boiler）has become a large commercial combustion technology after the pulverized coal boiler,because of its wide range of fuel types,relatively low pollution control and the good adaptability to load change,so it has been developed vigorously in China.However,with the continuous improvement of environmental protection standards in China,the standards of pollutant emission from thermal power boilers are rising,and the pressure of energy saving and emission reduction is increasing.The China is existing large number of industrial CFB boiler,their problems of low thermal efficiency,poor operation stability and not reach standard of pollutant emission which are urgently to be solved.Because the contradiction between the face of the increasingly severe environmental emission pressure and the industrial CFB boiler exceeding standard emission,we need to respond to the national call for energy saving and emission reduction in 13th Five-Year National Plan and optimize the combustion performance of the industrial CFB boilers,which is important to the sustainable development strategy of China.The thermal efficiency test and first or secondary air uniformity test prepared for 75t/h and 130t/h two CFB boiler,which in an aluminum oxide plant of Chongqing.To analyse the reasons for the low thermal efficiency and find out adaptation and ecoromic schemes.The main contents include the thermal efficiency test of the boiler,the uniformity test of the air distribution,the measurement of boiler’s heat loss,the measurement of oxygen distribution in the furnace and the homogeneity adjustment of the coal are so on,the improvement plan mean to solve the main problems of the boiler operation.The main conclusions obtained through the study are as follows:（1）The thermal efficiency of the two CFB boilers is only about 85%.The main heat loss is the loss of exhaust smoke and the incomplete combustion of solid.The emission of the pollutants is more than the 200 limit of the city of Chongqing,so the support of the technical transformation for the boiler is urgently needed.（2）With the increase of boiler capacity,the depth ratio of the CFB boiler increases,and the secondary air outlet laying out in the front and rear walls is more conducive to combustion in the furnace.（3）For the two CFB boiler we have been achieved the remarkable results from three aspects of combustion optimization,operation stability and pollution control.For example,for the 130t/h CFB boiler,the solid incomplete combustion heat loss q4is reduced from 6.02%to 1.66%,and the combustion efficiency of the boiler is also increased close to 4.4%. |
