RESEARCH ON SUPERCRITICAL CIRCULATING FLUIDIZED BED BOILER

摘要

The world's largest 600MW supercritical circulating fluidized bed (SCCFB) boiler was successfully put into operation with the full load in the end of March 2013 and passed commissioning test in middle April, 2013 in Baima Power Plant in Sichuan, China.This paper introduces the key design and tested performance of the boiler.The main steam parameters of the SCCFB boiler are 25.4MPa and 571℃/569℃.The structure of the furnace is of pant-leg type with two sets of air distributors, 6 steam cooled cyclones and 6 external heat exchangers (EHEs).The media flow rate was chosen as lower than 800kg/m2.s, which was proved to be safe by calculation and laboratory test at Tsinghua University.Some laboratory experiments and the results regarding to the gas solid hydrodynamics in the ultra-high furnace, the mal-distribution of gas solid flow among the multiple parallel cyclones and the system stability analysis in the large furnace especially on bed material balance between the two pant-legs are introduced.In addition, some industrial measurements on the large CFBs, which are used to calculate the 3D heat transfer coefficient distributions, are reported.Besides, the development of the auxiliary systems, such as the ash cooler with high capacity, in-furnace desulfurization system and the 600MW dynamic simulator are introduced.At last, some test results of the performance of the SCCFB boiler are given and discussed.It was found the deviation of the bed temperatures between the design and the operation was less than 5 ℃.The lateral temperature distribution along the lateral membrane wall was predicted successfully by the model calculation.