Based on the structure of water-cooled screen for a 350 MW supercritical CFB boiler manufac- tured by Shanghai Boiler Works Co. , Ltd. , an experimental setup was established to study the air-water two-phase flow in vertical header of the water-cooled screen. Meanwhile a numerical model was set up for the two-phase flow distribution based on mass conservation, momentum conservation and supplementary e- quations, with which flow distribution in the vertical header was calculated at 35 ~//0 BMCR and different dryness of steam, so as to obtain the mass flow coefficient of uniformity, maximum mass flow deviation coefficient, gas volume coefficient of uniformity and maximum gas volume deviation coefficient in each branch tube. The calculated results were compared with experimental measurements. Results show that under single operating condition, from branch tube 1 to branch tube 4, the mass flow increases gradually; the mass flow deviation coefficient increases from negative to positive; the gas volume flow reduces gradu- ally; the gas volume coefficient of uniformity decreases from positive to negative. The variation tendency of calculated data agrees well with experimental measurements, and with the rise of steam dryness, the er- ror reduces between the calculated results and actual measurements.
supercritical CFB boiler
flow distribu tion