Research on Dry-Wet Conversion Strategy of Supercritical Thermal Power Units Under Deep Peaking Condition

Abstract

To seek applicable dry-wet conversion mode in deep peaking condition, two different dry-wet conversion strategies were performed on two supercritical thermal power units to study the dry-wet conversion under coordinated control mode and its impact on the system stability. The results show that both strategies could realize the dry-wet conversion under coordinated control mode and further deep peaking could proceed via the dry-wet conversion. Moreover, the dry-wet conversion could be conducted either by co-control of coal and water or by feedwater control, yet the coal-water ratio varied. During the dry-to-wet process, affected by the two strategies, the system stability (the temperature and pressure of the main steam) is changed from dry state to wet state. In contrast, the system stability for both strategies is proved qualified under the conversion from wet state to dry state.

Keywords

• thermal power units
• deep peaking
• dry-wet conversion
• coordinated control
• system stability