Exergo-Economic Fuel-Impact Analysis for Steam Turbines Sections in Power Plants

Abstract

In this paper exergoeconomic fuel-impact models for steam turbines in power plants are proposed. They are applied to calculate the impact on the steam cycle when malfunctions are occurring during the operation of steam turbine sections. Concepts such as the exergetic consumption and the dissipation temperature are used to understand the proposed fuel-impact analysis. In order to validate these fuel-impact methods, well-known procedures, to simulate on- and off-design conditions of a steam power cycle, are used as references. Three different methods a) ASME PTC-6, b) existing fuel-impact formula, and c) proposed exergoeconomic Fuel–Impact formulation, are compared with respect to the simulator results. The proposed models allow evaluating fuel-impact cost with more accurate results than conventional procedures. An example of a 158 MW conventional power plant is presented herein. The malfunction costs occurring in the steam turbines are inferred from the results. One perspective of this analysis is to establish an on-line monitoring system into power plants that permits to opportunely detect steam turbine malfunctions, without simulators.

Keywords

• exergetic cost, unit exergetic cost, exergetic efficiency