Through coupling the high flue gas rotary drier together with the boiler system

the theoretical analysis model of high flue gas pre-drying lignite was established.The method to calculate the high flue gas flow needed for pre-drying and evaluate the unit economy was proposed.The calculation results show that

the coal consumption rate can be reduced by 1.39

2.10 and 0.96g/(kW·h)

by using the flue gas pre-drying technology to lower the moisture of the lignite from 38%to 27%

20% and 14%

respectively.With a10 degree centigrade decrease in the exhaust gas temperature of the pre-drying lignite power plant

the coal consumption rate can be reduced by 1.3g/(kW·h).In order to achieve the optimum economy

the heat loss due to exhaust gas and the dryer heat loss need to be considered together to determine the level of predrying lignite.