The fuel flexibility of a gas turbine combustor is numerically studied

and the combustor performance is obtained when firing the natural gas and coal-derived gases of different heat values(16.44

14.65 and 12.98 MJ/m~3

standard state). Moreover

the characteristics of flow field and temperature field in the combustor are analyzed. The results show that

under constant thermal power conditions

the uniformity of combustor outlet temperature reduces with the fuel heat value

but it can still meet the requirements within a certain range. While under the constant inlet fuel pressure condition

the thermal power of the combustor reduces with the fuel heat value

but the uniformity of outlet temperature is improved. Thus

when the combustor is modified to burn coal-derived gases

the thermal power should be reduced properly or the nozzle structure should be retrofitted correspondingly to maintain the durability and stability of the combustor.