Cold Experimental Study On The Cyclone Separator In A Large-scale Circulating Fluidized Bed Boiler

The circulating fluidized bed (CFB) boiler will gradually become the leader of the new generation clean coal combustion technologies instead of the coal powder boiler in the plant boiler field because of its advantages. To satisfy the increasing requirement of the electric power results from the ceaseless social development, the CFB boiler has increased its capacity for a long time. With the scale-up development, the complicate system and huge configuration bring lots of problems include the cyclone separator. It's necessary to augment the volume and the capacity of the cyclone separator, but the super large-scale separator shows lots of disadvantages such as ponderous structure, increasing flow resistance force, decreasing separating efficiency. Therefore, we have to limit the maximum diameter of the main body between 7~9m. It is the difficult problem for the design and disposal of the cyclone separator. So, experts, scholars and boiler companies are trying to modify the configuration and change the flow parameter to increasing its separating efficiency and making the disposal more reasonable.In order to solve these problems, a visual cold test-bed based on the 100MW CFB boiler in the plant of YiBin, in SiChuan Province, was built. Using the floating bead as the bed material, we did experiments and numerical simulation to study the mechanics of gas-solid two phase flow. Therefore, we can study the advanced CFB combustion technology and do something for the technical storage.The main tasks of the cold test:â‘ Measuring and computing the separating efficiency and pressure loss of the two kinds of cyclone separator in different operating mode.â‘¡Simulating the flow of the separator in some typical operating mode mentioned above and analyzing by contrasting with the test study.â‘¢Simulating the flow of the separator which use the entrance structure modified by ALSTOM( France company ) to study the relationship between the entrance structure and the separating efficiency.The results of the cold experimental study mainly include:â‘ The critical fluidizing velocity of the furnace is 0.2m/s, which is approximate to the one achieved by computing with the experience formula (0.178m/s).â‘¡The separating efficiency increase with the inserting length of the vent-pipe, on the contrast, the pressure loss drop down.