Based on “the heat quantities method”

and considered fully the actual condition of a thermal power plant （TPP）

the electric energy consumed by auxiliaries in a TPP has been divided into four parts

namely: （1） for pure condensing power generation; （2） for pure heat supply; （3） for chemical water treatment

that should be shared for electricity generation and heat supply; （4） for the public station service. By this way

an accurate cost sharing for electricity generation and for heat supply has been realized

making the coal consumption cost for heat supply and for electric supply can be calculated more conforming to reality. Taking three 200 MW units in a TPP as practical example

the economic indices have been analysed and calculated.