On the basis of investigation and integration on calculation methods of coal blending characteristics

a mathematical analysis model and theoretical method were proposed.The parameter characteristics of lignite mixed with other coals were determined

and the quantum particle swarm theory was employed to check and calculate the parameter equation.By the sectional calculated CFB furnace heat transfer model and the general boiler thermal calculation algorithm adopting sequential modular iterative

the thermal calculation for CFB boilers firing mixed coals with different proportions of lignite were conducted

under varied coals and varied operation conditions.Furthermore

the effect of lignite proportion on boiler's operation parameters was analyzed.Finally the reasonable mixed ratio was determined(50%-70%).Moreover

the operation performance of large scale CFB boiler firing mixed coal with high proportion of lignite was optimized.After the improvement

the boiler efficiency was enhanced by 2.045%to 3.174%

and the comprehensive auxiliary power ratio was decreased by 0.458%to 1.127%.