Research Progress on the Dynamic Characteristics of Circulating Fluidized Bed Boilers While Processing Rapid Variable Loads

Abstract

In order to achieve the “dual-carbon” goal, China’s energy sector is rapidly evolving towards a green and low-carbon future, with the integration of large-scale new energy into the power grid. However, due to the fluctuating characteristics of new energy generation, the difficulty of grid peaking has gradually increased. Consequently, enhancing flexibility and achieving wide and rapid peak shaving have emerged as the primary development directions for thermal power units. Circulating fluidized bed (CFB) boilers have been widely developed due to their excellent coal adaptability, large load regulation range, and low-cost pollutant removal ability. However, the flexibility of load variations in most CFB units is not high, limited by the substantial inertia of the furnace side and fluctuating pollutant emissions. This review is conducted with respect to the boiler side to analyze inertia sources and effects on the system while processing rapid variable loads, including gas–solid flow inertia, fuel combustion inertia, and heat transfer inertia. It discusses the development of numerical simulation models for CFB boilers and points out corresponding applications and limitations in simulating dynamic characteristics during load changes. Through experimental bench tests and numerical simulation, it investigates the dynamic characteristics of pivotal parameters in the variable load process. Moreover, the pivotal elements influencing the variable load performance and viable regulatory techniques are revealed, thereby furnishing theoretical guidance for enhancing the unit flexibility and peak shifting rates of China’s CFB boilers.

Keywords

• circulating fluidized bed
• rapid variable load
• dynamic characteristics
• flow inertia
• combustion inertia
• heat transfer inertia