Performance Analysis of a Regenerative Rankine Cycle with Emphasis on Component Level Design

In this article, the steady performance of a regenerative Rankine cycle is evaluated using the Flownex software. The configuration has one open water heater (OWH) and one closed water heater (CWH). The OWH, the boiler, the hot sides of the CWH and the condenser are considered as two phase tanks. Two composite heat transfer (CHT) elements are used to model the transfer of heat in the CWH and condenser. The components’ geometry is taken into consideration during the performance evaluation. The pressure drops are calculated using appropriate equations. The steam turbine speed is taken as 3000 rpm and the speed of the pumps is adjusted to facilitate the required mass flow rate. The turbine inlet temperature and pressure are 550 °C and 12.5 MPa while the condenser pressure is 10 kPa. The pressure of steam extracted from the steam turbine for the CWH and OWH are selected optimally to maximize the power and these are found to be 2.56 MPa and 0.518 MPa respectively. Finally, an exergy analysis is performed to evaluate the irreversibility of the system components. From the results, the net power production of the plant is found 98.998 MW and its thermal efficiency is 41.946%. The exergy analysis showed that the boiler has the highest irreversibility with the steam turbine, condenser, OWH and the CWH to follow. The total plant irreversibility is found to be 124.179 MW.