Thermodynamics and Power Plant Efficiency

Simplified the net efficiency of coal-fired steam power plants can be written as product of the partial efficiencies of the ideal thermodynamic cycle J/th.id, steam generator rjsc (boiler efficiency), steam turbine j/x, generator j/g, and the equivalent 

While the steam generator efficiency t)sg 0.92), the steam turbine efficiency (j/x = 0.9-0.92), the generator efficiency (t/q 0.98), and the corresponding efficiency for the power plant s electrical auxiliary power consumption ( /aux io 0.93) all have relatively high values above 0.9, the net efficiency of a coal-fired steam power plant is mainly affected by the thermal efficiency of the cycle /th,id which today is about 0.55. Besides the minimization of losses by an optimized flue gas heat utilization, the application of optimized turbine blading, or the reduction of the auxiliary power consumption, the main potential for enhancing the overall power plant efficiency can be seen in increasing the live steam parameters. 

To put it simply, these mean temperatures can be derived from the specific enthalpies h and specific entropies s of the Rankine cycle by the following equations  

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