In order to overcome the difficulty in real-time coal quality monitoring for utility boilers

a calculation model for coal's calorific value was established

on the basis of air volume

coal quantity and oxygencontent signals.By analyzing the main coal quality data

the relationship between theoretical air volume

theoretical gas volume and coal's calorific value was constructed.Then

the real-time calculation model for coal's calorific value was established

to eliminate the influence of inaccurate air volume

air leakage and incomplete combustion.Moreover

simulation on a power plant under steady load condition and fast variable operating conditions was carried out

and the results show that this calculation method is convenience and the uncertainty of the calculation results is relatively low.