Abstract: This paper analyses energy economy efficiency (Yong efficiency) of thermal system of fossil fuel power plants(FFPPs) roundly.At the same time,based on the green zoology protection point,the calculating model of zoology efficiency has been analysed.From System-Green-Yong-Economic-Coefficient,and taking the lowest cost of generate electricity as springboard,this paper establishes the optimization formula of System-Green-Yong-Economic-Coefficient.Taking the benefit of superaddition invest of components as object,components,which need ameliorating,are ascertained.At the same time,the synthetical coefficient function of which are established.

Key words: fossil fuel power plants, energy system, ecotype heating economy, zoology efficiency, optimization analysis