Currently

in engineering

the calculation of air preheater leakage rate is mainly according to the method provided in the appendix K of GB10184—88Performance test code of utility boiler.This method is applicable to the conventional pulverized coal boiler

but it can not be used for the boiler mixedly burning pulverized coal and blast furnace gas(BFG).In addition

for the indirect-fired coal-storage pulverizing system

the amount of coal into the furnace can not be measured accurately

which can cause the difficulty in obtaining the mixed fuel properties and thus adversely affect the calculation of the air preheater leakage rate.Aimed at this problem

an iterative calculation scheme for solving the mixed fuel properties was proposed

to avoid the difficulties resulting from the direct measurement of coal into the furnace.The air preheater leakage rate calculation model that is suitable for boilers mixedly burning pulverized coal and BFG was put forward

and the results can provide references for air preheater leakage test of mixedly-burned boiler.