Selection of Steam Inlet Parameters for 1000MW Double-Reheat Units Based on the Backpressure Extraction Steam Turbine System

This study focuses on a 1000MW double-reheat unit equipped with the backpressure extraction steam turbine (BEST) system. A comprehensive thermodynamic simulation model was developed using EBSILON software to investigate the effects of main steam pressure, main steam temperature, primary reheat steam temperature, and secondary reheat steam temperature on unit efficiency. Based on P92 material properties, various steam inlet parameter schemes were determined and simulated. Comparative analysis was conducted from multiple perspectives including heat rate improvement, main equipment cost, investment in major piping systems, and auxiliary equipment expenses. The optimal steam inlet parameter scheme was identified and subsequently applied to a 2×1000MW ultra-supercritical unit expansion project in a power plant. The research results demonstrate that the optimal steam parameters are 32MPa/600°C/623°C/620°C.