Performance evaluation of a 220t/h CFB boiler with water-cooled square cyclones

The first Chinese 220 t/h CFB boiler was successfully demonstrated. The boiler was compactly designed with Tsinghua-patented, water-cooled square cyclones with curved inlet based on previous experience of similar CFB boilers of smaller capacities. The demonstration showed that the boiler possesses excellent performance in start-up, fuel flexibility, flexibility to frequent turn-down ratio variation, facility availability and reliability. The performance of the water-cooled square cyclone was compared with that of other cyclones through fly ash analysis. The results showed that the overall performance of the square cyclone in such capacity is compatible to that of the round cyclone, meeting the requirements for material balance and efficient combustion in CFB boilers. The demonstration was a milestone for CFB boiler scaling-up in China.