A comparison between two different approaches aimed at simulating the behaviour of combined cycles in transient conditions

The deregulated energy market and the increasing quota of installed power by non-predictable renewable sources require to thermal power plants strongly irregular and discontinuous operation to meet the user demand and to compensate the variability of renewable sources. As a consequence, a lifetime reduction of the most critical components is likely to occur, due to thermo-mechanical fatigue, creep and corrosion. The availability of a procedure that predicts the residual life of the plant devices is necessary to assist the management decision about power plants’ operation and maintenance scheduling. The first step of the procedure is the capability of evaluating the trends of the main thermodynamic parameters that describe the plant operation during different transient periods. At this purpose, in the present paper, two different approaches developed by two research groups are compared applying them to simulate a combined cycle power plant characterized by a single pressure heat recovery steam generator.