Operating technical characteristics on asymmetrical arrangement of six cyclones in a 600 MW supercritical CFB boiler

Abstract

In order to obtain the operating characteristics of the first 600 MW supercritical circulating fluidized bed (CFB) boiler with six cyclones in an asymmetrical arrangement, the gas-solid flow information and temperature distribution of six circulating loops were measured and analyzed. The experimental results indicate that bed temperature in the furnace presents an S-type distribution pattern along the furnace height direction, for three cyclones of the same side, the temperature in the middle cyclone is high and the temperature on both side cyclones is low. At high boiler loads (450–600 MW), the temperature distribution of six cyclones and the gas-solid flow uniformity along the furnace height direction is more uniform, the temperature distribution uniformity in dense phase zone of furnace and three circulating loops on the right side wall are superior to those of the left side wall. The calculation results indicate that the particle flow distribution of six cyclone inlets is relatively uniform, the calculated results are consistent with the test results. The gas-solid flow asymmetry phenomenon of six circulating loops on both sides of the furnace is found, and the relative standard deviation of six cyclones inlet temperature does not exceed 4.30%, the back pass structure needs further optimization.