Abstract: Based on the heat balance diagram of 600MW unit, the key data points in rated condition were analyzed, and relevant thermal efficiency data can be obtained by calculating according to the key data points. The coal consumption rate and unit thermal efficiency will vary with the variation of the field operation parameters. Therefore, it is can find that in which respects the unit need adjustment or reformation by analysis of key points data variation, and the key link for decrease the coal consumption rate of power plant can be grabbed. The emphasis of this paper is analysis of coal consumption data of steam turbine thermal power system, the coal consumption rate in this paper was obtained by heat balance calculation according to the relevant data of heat balance diagram.

Key words: Benchmarking, coal consumption, heat balance, steam turbine