Numerical Simulation of a Circulating Fluidized Bed Desulfurization Reactor with Bypass
The semi-dry desulfurization process in circulating fluidized beds (CFB) is sensitive to reactor flow field, which directly impacts desulfurization efficiency. To accommodate variable flue gas loads while maintaining constant Venturi tube velocity, a bypass structure crossing the Venturi section was introduced between the reactor inlet and diffusion section. Numerical simulations using ANSYS Fluent were conducted to evaluate the effects of bypass valve opening and number of bypass pipes on flow field uniformity and pressure loss. Results indicate that for flue gas load variations, bypass valve openings must exceed 50% and at least two bypass pipes are required to ensure uniform flow distribution. At 100% flue gas load, the empty reactor pressure loss was 911 Pa, decreasing to approximately 500 Pa at lower loads. The optimized bypass configuration enables stable and uniform flow fields with reduced pressure loss across a wide load range of 50%–100%, offering an effective solution for enhancing desulfurization efficiency and operational adaptability in industrial applications.