Investigation on Hydrodynamic Performance and Wall Temperature of Water-Cooled Wall in 1000 MW Boiler Under Low-Load Conditions

To enhance the peak-shaving capability of a boiler, a mathematical model of hydrodynamic and wall temperature characteristics for the water-cooled wall of a 1000 MW boiler was established. Utilizing the component pressure method, the mass flow distribution, outlet working fluid temperature, pressure loss, and wall temperature distribution characteristics of the water-cooled walls at 30% of the boiler’s maximum continuous rating (BMCR) were calculated and analyzed. The findings suggest that, under the operation at 30% BMCR load, there is a substantial equilibrium in the flow distribution across the quartet of walls that constitute the water-cooled wall assembly. The maximum mass flow rate deviations in the helical and vertical sections are 1.95% and 3.47%, respectively, showing small flow deviations and reasonable distribution. The temperature deviation in the helical section is 0.3 °C, reflecting the characteristic low thermal deviation in helical tubes. While the temperature deviation at the outlet of the vertical section is higher, it remains within safe limits. The pressure loss across the water-cooled wall system amounts to 0.4 MPa. The peak wall temperature reaches 337.5 °C, remaining within the material’s permissible safety limits. Through an in-depth performance analysis, the hydrodynamic operational safety under 30% BMCR deep peak-shaving load is ensured.