Dynamic Characteristics Analysis of a 660 MW Ultra-Supercritical Circulating Fluidized Bed Boiler

Abstract

The 660 MW ultra-supercritical circulating fluidized bed (CFB) boiler, which is the maximum capacity and largest scale boiler in the world has entered construction stage in China. This study established a full-scale dynamic simulation model of the 660 MW ultra-supercritical at 100% boiler maximum continuous rating (BMCR) condition. The model consists of an air-flue gas system, a water-steam system, and an ash circulation system. The “core-annulus” of the gas-solid two-phase flow structure and “six-equation” model of water-steam two-phase flow were applied to simulate the behaviors of the gas-solid phase and water-steam system, respectively. The model was calibrated and verified at 100% BMCR condition, and the steady-state simulation results presented a high accuracy compared with the designed parameters. A dynamic simulation of three typical conditions were carried out as well, including a 5% feed water decrease, 5% air decrease, and 5% coal decrease, respectively. The results showed that the dynamic simulation model established in this study can simulate the dynamic behaviors of the 660 MW ultra-supercritical CFB boiler reasonably.