Operation optimization analysis of 600 MW steam turbine under new situation

Abstract It is of great significance to study the operation optimization of thermal power units under the new situation and the economic operation under low load. The bearing vibration of a 600 MW thermal power unit has been too large since it was put into operation, and steam distribution optimization and sliding pressure optimization were not carried out since the unit was put into operation. In order to solve the vibration hidden trouble of the unit and explore the energy saving potential, the operation optimization test of the steam turbine is carried out. When the valve sequence is changed from GV1/2-GV4-GV3 to GV2/3-GV1-GV4, the maximum vibration of #2 bearing decreases from 150-170 μm to 50-60 μm, and the maximum vibration of #1 bearing decreases from 90-100 μm to 30-40 μm. After optimization of steam distribution, the regulating characteristics of the unit are improved obviously, and the gap between the equivalent main steam flow feedback and the ideal value of the overall flow characteristics of the sequential valve decreases from 15.20% to less than 1%, and the load and valve of the unit change steadily in the process of switching between single valve and sequential valve. Five load conditions were carried out in the sliding pressure optimization test, and the sliding pressure curves were obtained when the back pressure was 3.35kPa, 4.9kPa and 7.95kPa. After optimized operation, the coal consumption of thermal power unit is reduced by 1.47g/(kW⋅h) on average.