Second-law-based thermodynamic analysis of regenerative-reheat Rankine-cycle power plants

We examine the performance of regenerative-reheat power plants in terms of irreversibility analysis. The reduction in the irreversible losses with the addition of backward, cascade-type feedwater heaters and/or a reheat option are compared with a conventional energy-balance approach. The results indicate that most of the irreversible losses occur in the boiler and that these losses are significantly reduced by the incorporation of feedwater heating. The incorporation of feedwater heating results in a reduction of the total irreversibility rate of the cycle by 18%. The corresponding improvement in efficiency is 12%. These two figures are augmented to 24 and 14%, respectively, by the incorporation of reheat in addition to regeneration.