Supercritical CO2 boiler capable of realizing uniform combustion, corrosion resistance and coking resistance, and boiler system

A supercritical CO2 boiler capable of realizing uniform combustion, corrosion resistance, and coking resistance, comprising a main combustion chamber, an upper furnace, a furnace arch, and a flue, wherein the upper furnace is vertically disposed at an upper end of the main combustion chamber, and an upper end of the upper furnace is communicated with one end of the flue through the furnace arch;

• a cross section of the main combustion chamber is circular or oval, or the cross section of the main combustion chamber is of an N-sided shape, where N>4;
• at least four groups of burner nozzles are disposed on a side wall of the main combustion chamber, and the at least four groups of burner nozzles are evenly spaced and distributed on the side wall of the main combustion chamber;
• each of the at least four groups of burner nozzles comprises a recirculating air nozzle, a primary air nozzle, and a secondary air nozzle, wherein lateral recirculating air nozzles symmetrically distributed are disposed at two sides of the primary air nozzle respectively, the recirculating air nozzle and each of the lateral recirculating air nozzles are configured to feed recirculating flue gas or a mixed gas of the recirculating flue gas and secondary air into the main combustion chamber respectively, the primary air nozzle is configured to feed primary air or a mixed gas of the primary air and the recirculating flue gas into the main combustion chamber, the secondary air nozzle is configured to feed the secondary air or the mixed gas of the secondary air and the recirculating flue gas into the main combustion chamber, and an air velocity at each of the lateral recirculating air nozzles is higher than or equal to an air velocity at the primary air nozzle, and
• an air temperature at either of the recirculating air nozzle and each of the lateral recirculating air nozzles is 300-800° C., and an air temperature at the secondary air nozzle is 300-800° C.;
• or each of the at least four groups of burner nozzles comprises the recirculating air nozzle and a swirl combustion nozzle, wherein lateral recirculating air nozzles are disposed on two sides of the swirl combustion nozzle respectively, an inner swirl nozzle of the swirl combustion nozzle is configured to feed the primary air or the mixed gas of the primary air and the recirculating flue gas into the main combustion chamber, an outer swirl combustion nozzle of the swirl combustion nozzle is configured to feed the secondary air or the mixed gas of the secondary air and the recirculating flue gas into the main combustion chamber, the recirculating air nozzle and each of the lateral recirculating air nozzles are configured to feed the recirculating flue gas or the mixed gas of the recirculating flue gas and the secondary air into the main combustion chamber, and the air velocity at each of the lateral recirculating air nozzles is higher than or equal to a maximum air velocity at the swirl combustion nozzle;
• and
• the air temperature at the recirculating air nozzle and each of the lateral recirculating air nozzles is 300-800° C., and an air temperature at the outer swirl combustion nozzle of the swirl combustion nozzle is 300-800° C.