Thermodynamic Performance Optimization of Steam Turbines in Nuclear Power Plants

Abstract

The thermodynamic performance of steam turbines plays a critical role in determining the overall efficiency and sustainability of nuclear power plants. This study investigated and optimized the thermodynamic behavior of a nuclear steam turbine system using energy analysis, exergy analysis, statistical evaluation, and computational optimization techniques. A Rankine cycle-based thermodynamic model was developed using operational parameters including turbine inlet temperature, condenser pressure, steam mass flow rate, turbine work output, and thermal efficiency. Simulation and optimization analyses were conducted to evaluate the effects of operating conditions on turbine performance and system irreversibility.

The results showed that increasing turbine inlet temperature from 280°C to 360°C improved thermal efficiency from 31.5% to 38.9%, while exergy efficiency increased from 63.2% to 77.4% after optimization. Conversely, increasing condenser pressure from 5 kPa to 13 kPa reduced exergy efficiency from 78.5% to 68.4% due to increased entropy generation and reduced turbine expansion ratio. The optimized system demonstrated significant performance enhancement, including a 13.17% increase in thermal efficiency, 22.47% increase in exergy efficiency, and 10.77% increase in turbine work output. Exergy destruction reduced substantially from 64.5 MW to 39.7 MW, while specific steam consumption decreased by approximately 17.84%.Exergy destruction analysis revealed that the steam turbine recorded the highest irreversibility of 39.7 MW, followed by the steam generator with 28.6 MW and the condenser with 17.5 MW. Statistical analysis showed a very strong positive relationship between turbine inlet temperature and thermal efficiency with a Pearson correlation coefficient of 0.99575 and coefficient of determination (R²) of 0.99152. Sensitivity analysis further identified turbine inlet temperature and condenser pressure as the most influential parameters affecting system performance. The study demonstrates that optimization of turbine operating conditions significantly improves energy conversion efficiency, reduces thermodynamic losses, and enhances the operational reliability of nuclear power plants. The integration of thermodynamic modeling, exergy analysis, and statistical optimization therefore provides an effective framework for improving the performance and sustainability of modern nuclear steam turbine systems