Experimental Analysis And Optimization Study On Temperature Characteristics Of 300MW Circulating Fluidized Bed

Although the imported 300MW circulating fluidized bed(CFB) boiler technology is very distinctive, but it has a lot of problems which does not adapt to China’s current national conditions, such as operating problems, high cost and investment of the boiler, etc. Therefore, domestic manufacturers have also developed 300MW CFB boilers with independent intellectual property rights, while the introduction of foreign advanced boiler technology. During operation, it is found that the bed temperature distribution does not uniform in a kind of CFB boiler, which has independent intellectual property rights. The bed temperature of CFB boiler is an important parameter, which directly affects the chemical reaction rate of the fuel and the safety and stability of the boiler operation. Therefore, this paper hopes to find out the specific reasons for the bed temperature deviation in this type boiler and put forward the adjustment plan, which could provide effective solution to this problem.According to the existing research results, this paper has carried on the research, which based on the domestic same type boiler in one power plant, contents of the following aspects:Firstly, it has been carried out that the operation data analysis of the boiler unit and the field test of the static pressure distribution in the water cooling air chamber. Then, the influence of static pressure distribution on the temperature deviation has been deeply analyzed based on the test results. Secondly, the throttling scheme of local hoods has been put forward together with the owner based on the experience in related modification and the effect of this scheme has been analyzed. At last, the inlet gas velocity of the cyclone separator has been measured for comparing the difference between the separation efficiency of the three cyclone separators, which based on the research level of the project group.The research has shown that the static pressure deviation, between the middle and both sides of the water cooling air chamber in the boiler, is very small, which has less effect on the bed temperature. But the bed temperature deviation affected by air chamber overall static pressure, which could be reduced through increasing the primary air flow appropriately. Through the experimental study, it is found that the inlet gas velocity of the cyclone separator in the middle of the boiler is relatively low, so that the separation efficiency of the middle separator is lower than that of the two sides. In this paper, the structural optimization of the central cylinder of the two sides separator and the middle separator has been proposed.