BIOMASS-ONLY COMBUSTION BURNER, BIOMASS-MIXED COMBUSTION BOILER, AND BIOMASS FUEL COMBUSTION METHOD

摘要

The present invention provides a biomass combustion burner applied to a pulverized coal-fired boiler to burn biomass fuel, a biomass-mixed fired boiler that reduces an amount of CO2 derived from fossil fuels, and a method for burning biomass fuel using the foregoing. The biomass combustion burner includes a biomass fuel jet nozzle (10) having a fuel jet port (19) that jets biomass fuel conveyed by primary air; a secondary air nozzle (20) having a secondary air jet port (23) that surrounds the fuel jet port; and a tertiary air nozzle (25) having a tertiary air jet port (27) that surrounds the secondary air jet port. The biomass fuel jet nozzle includes a fuel concentration adjusting section (15) that changes a biomass fuel stream into a swirl flow to thereby make a fuel concentration higher on an outer circumferential portion side; and a degree-of-swirl adjusting plate (17) that reduces a degree of swirl of a jetting fuel stream. An amount of the secondary air is reduced and a buffer stream is formed between the fuel stream and a tertiary air stream to thereby improve ignitability and flame holding performance.