Exergy analysis of the turbine system in a 1000Â MW double reheat ultra-supercritical power plant

This study aims to achieve exergy distribution in a turbine system for a 1000 MW double reheat ultra-supercritical power plant. An exergy balance equation is used to identify the real points of energy loss in the turbine system, which can provide a reference for optimizing operation and conserving energy. Results show that irreversibilities yield the highest exergy loss in the turbine, particularly in the very high pressure (VHP) and low pressure (LP) cylinders. Compared with that in the turbine of a single reheat unit, exergy loss in the studied turbine is higher and exergy efficiency is lower. For the regenerative system, exergy loss is lower and exergy efficiency is higher in the double reheat unit than in the single reheat unit. Thus, the layout of the regenerative heaters in the double reheat unit is more reasonable. However, exergy loss in high pressure regenerative heater Nos. 3 and 6 and low pressure regenerative heater Nos. 7 and 10 in the heat recovery system is extraordinary because of different reasons. Exergy loss in the condenser of the double reheat unit is relatively smaller than that in the condenser of the single reheat unit.