The invention discloses a
biomass direct-fired boiler. The
biomass direct-fired boiler comprises a boiler body, a feeding
system, a discharging
system, an out-boiler gas
flue, a primary air inlet chamber, a secondary air inlet
pipe and a distribution device; a
combustion chamber which is formed by membrane type
water cooling walls and a multi-return
stroke gas
flue are arranged in the boiler body; a
water cooling vibrating fire grate is arranged at the bottom of the
combustion chamber; a steam super-heater is arranged in the multi-return
stroke gas
flue; the feeding
system is communicated with the front wall of the boiler body, and is used for inputting a
biomass fuel into the
combustion chamber; the discharging system is arranged at the bottoms of the multi-return
stroke gas flue and the
water cooling vibrating fire grate, and is used for outputting
burnout things of the biomass fuel out of the boiler; the out-boiler gas flue is communicated with the top of a
tail return stroke gas flue; a
coal economizer, a secondary air pre-heater and a primary air pre-heater are arranged in the out-boiler gas flue in sequence in a
flue gas flowing direction, and are used for preheating fed water and air and feeding the preheated water and air into the boiler; the primary air inlet chamber is arranged below the water cooling vibrating fire grate; the secondary air inlet
pipe and the distribution device are arranged on the side wall of the
combustion chamber. According to the biomass direct-fired boiler, the biomass fuel adaptability is wide; the combustion and energy resource conversion efficiency is high; the boiler operates safely and stably; high-efficiency utilization of biomass
energy resources is realized.