Thermo-economic analysis of combined gas-steam systems; A valid engineering and monitoring tool

In this paper the authors outline a thermodynamic and economic analysis of combined gas-steam plants in order to compare the respective indications for the two approaches with the ultimate aim of making a well-founded choice of system. This thermo-economic analysis shows that, quite often, the ideal thermodynamic conditions do not coincide with the most advantageous economic conditions; furthermore, it is also sensitive to the several cost variations. On the whole it shows that an engineering criterion which considers the effects of economic parameters as secondary and which does not include the attainment of lowest cost-conditions as one of its primary goals, must be deemed inadequate.