Thermal–Hydraulic Calculation and Analysis on Water Wall System of a 700 MWe Ultra-Supercritical CFB Boiler

Abstract

Ultra-supercritical circulating fluidized bed (CFB) boiler combustion technology has the advantages of environmental protection and good commercialization. As one of the key aspects in ultra-supercritical CFB combustion technology, the water wall system directly determines whether the CFB boiler can safely and effectively transform heat energy. This paper studies the thermal–hydraulic characteristics of the designed water wall system of a 700 MWe ultra-supercritical CFB boiler, the largest one that will be built next year. At four loads of the water wall system, hydrodynamic parameters are calculated based on the successfully verified mathematical models. The results show that the hydrodynamic characteristics of the system are good. The temperature distribution of the working fluid and metal of the water wall system is acceptable and safe at each load, which can support the technical development and improvement of the 700 MWe ultra-supercritical CFB boiler.

Keywords

• ultra-supercritical CFB boiler
• thermal–hydraulic analysis
• water wall system