If main operation parameters deviate from the target value

the boiler thermal efficiency will decrease and the unit coal consumption will rise.Thus

the key points in calculating gas boiler thermal efficiency was analyzed

and the energy-loss analysis model which is suitable for gas boilers was put forward.Taking a 220t/h blast furnace gas-fired boiler as the research object

the established model was adopted to calculate the coal consumption deviation resulted from the boiler operation parameters' variation

like the exhaust temperature

the oxygen content in exhaust

CO concentration in exhaust and so on.The results show this model can obtain the coal consumption deviation accurately

which provides a guidance for boiler optimization operation.