Comparative Exergy Analysis of Thermal Power Plant Systems

The concept of exergy, derived from the second law of thermodynamics, becomes a valuable source tool in analyzing thermal systems’ performance. Several terms encountered in the literature are synonymous or closely related to exergy, which are available energy, essergy, utilizable energy, and availability. The thermal efficiency of the power plants can be increased by adopting supercritical and ultra-supercritical conditions. Pressures exceeding 221.2 bar and steam temperatures exceeding 374.5°C are being used for supercritical thermal power plants, whereas the corresponding values for ultra-supercritical conditions are greater than or equal to 250 bar and 600°C. So, there is ample scope to enhance the steam conditions and optimize power plant configurations further to improve the plant efficiency. The power plant cycle is simulated by using Cycle Tempo version 5.0 software. It is used for advanced thermal energy system optimization. In the present work, for the thermodynamic analysis of supercritical—660 MW, and ultra-supercritical—800 MW power plant, cycle capacities are carried out and compared with subcritical power plant capacity of 500 MW. The important conclusions drawn from the current research work are the improvement in feed water temperature, optimum steam extraction pressures, and comparison of exergy efficiency of various thermal systems.