The thermal economic evaluation for sliding pressure operation in 330MW steam turbine

Based on the N330-17.75-540/540 steam turbine unit, the thermodynamic methods were firstly used to test the influence of the economics in different loads with different input pressures (fixed-pressure operation and sliding-pressure operation). And then the variation of the slightly increasing output was explored, which was caused by the exhaust pressure changes of the steam turbine. The best operation mode was determined after considering the unit security and the economic benefits. Finally, we obtained the optimally fixed-sliding pressure curve in the variable condition, as well as the unit relationship between a slightly increasing output and the exhausted pressure changes, those were beneficial for the economical operation and on-line monitoring.