Comparison of Thermal Power Cycles

This chapter summarizes the book by the comparison of all the thermal power cycles under a common platform. Some outcomes of the book have been drawn through this comparative analysis. All the thermal cycles of heat recovery power plants are consolidated in this comparative analysis. The organic Rankine cycle (ORC), organic flash cycle (OFC), steam Rankine cycle (SRC) and steam flash cycle (SFC) are compared and analyzed below and above the critical temperature of working fluid. The six working fluids used in ORC and OFC are R123, R124, R134a, R245fa, R717 and R407C. The performance of Kalina cycle (KC) is also added to differentiate with the ORC and OFC characteristics. R123 in OFC has been recommended to result in higher power compared to the other fluids. After the low temperature cycles (ORC, OFC and KC), the next level of source temperature has been analyzed with steam power cycles (SRC and SFC). The SRC, SFC with one flasher (SFC 1), and SFC with two flashers (SFC 2) are compared for the power and efficiency variations with a change in temperature and pressure. From the steam cycles, SFC 2 has been recommended to waste heat transfer for power augmentation. The analysis shows that the R134a and R245fa are not able to augment the power with OFC plant. OFC- R407C is only escalating the thermal efficiency in addition to the power augmentation due to the use of zeotropic working fluid. R717 exhibits maximum specific power with ORC and OFC with higher optimized heat recovery pressure.

Keywords: Comparative analysis, Energy efficiency, Power augmentation, Thermal power plants, Waste heat recovery.