In order to develop large CFB boilers with independent intellectual property, Xi’an Thermal Power Research Institute （TPRI） established a laboratory with complete functions for the technical development of CFB boilers. This laboratory consists of a 1-MW and a 4-MW CFB combustion test facilities and a laboratory for limestone desulphurization performance evaluation. It carried out tests on CFB combustion and desulphurization for Chinese typical coals and limestone and research on heat-transfer characteristics and key parts, and developed the first home-made 100-MW CFB boiler. Based on the experience of R＆D, the laboratory further researched key techniques for enlarging capacity systematically, and cooperating with Harbin Boiler Co. （HBC）, developed the first domestic 210-MW CFB boiler with independent intellectual property and put it into engineering demonstration, laying a solid foundation for the development of CFB boilers of even larger capacity.

The paper briefed the design features of the First domestic 210MW circulating fluidized bed(CFB)boiler,and analyzed the main technical problems met during the commissioning process,such as:deforming-buldging of interconnecting cover of air preheater, insufficient design strength of the rear wall of intermediate temperature economizer,and overtemperature of the outlet steam of low temperature reheater etc.Through improving the interconnecting cover baffle of air preheater,strengthening the rear wall of economizer, adjusting the heating surface of reheater,installing the soot blower at the inlet gas duct of separator and resolving the slagging of vertical pipe of separator etc.,the problems mentioned above were resolved.Operating results show that,after retrofitting,all the performance parameters of boiler have reached the design values and the boiler has good Operating performance.In particular,the compact ash-flow splitting and heat exchanger(CHE) applied first at home has stood up to all tests,operated stably,regulation is convenient and reliable and operation control performance is excellent.

Based on summarizing experiences in design,manufacture,and operation of the first home-made 100 MW circulating fluid- ized bed (CFB) boiler,a 210 MW CFB boiler has been developed.Results of practical operation show that the performane parameters of the developed boiler have been reached the designed values,rate of automatically putting the unit into operation to be 87.3%.suc- cessfully putting the home-made 210 MW CFB boiler into service has laid a solid foundation for the home-made 330 MW CFB boiler being just under construction.

The thesis introduces the problems, reasons and transformations appeared to operate the bottom ash cooler of the 100 MW CFBB in initial stage in Jiangxi Fenyi Power Plant.