摘要:
A solid fuel burner using a low oxygen concentration gas as a transporting gas of a low grade solid fuel such as brown coal or the like and a combustion method using the solid fuel burner are provided. The solid fuel burner comprises a means for accelerating ignition of the fuel and a means for preventing slugging caused by combustion ash from occurring. Mixing of fuel and air inside a fuel nozzle 11 is accelerated by that an additional air nozzle 12 and a separator 35 for separating a flow passage are arranged in the fuel nozzle 11, and the exit of the additional air nozzle 12 is set at a position so as to overlap with the separator 35 when seeing from a direction perpendicular to a burner axis, and additional air is ejected in a direction nearly perpendicular to a flow direction of a fuel jet flowing through the fuel nozzle 11. An amount of air from the additional air nozzle 12 is varied corresponding to a combustion load. By increasing the amount of air from the additional air nozzle 12 at a low load operation, an oxygen concentration of a circulation flow 19 formed in a downstream portion outside the exit of the fuel nozzle 11 is increased to stably burn the fuel. By decreasing the amount of air from the additional air nozzle 12 at a high load operation, a flame is formed at a position distant from the fuel nozzle 11 to suppress radiant heat received by structures of the solid fuel burner and walls of the furnace.
摘要:
A solid fuel burner and method uses a low oxygen concentration gas as a transporting gas for a low grade solid fuel such as brown coal or the like, provides for accelerating ignition of the fuel and for preventing slugging caused by combustion ash. Mixing of fuel and air inside a fuel nozzle 11 is accelerated by an additional air nozzle 12 and a separator 35 for separating a flow passage, arranged in the fuel nozzle 11, and an exit of the additional air nozzle 12 is set at a position that overlaps with the separator 35. Additional air is ejected in a direction nearly perpendicular to a flow direction of a fuel jet flowing through the fuel nozzle 11. The amount of air from the additional air nozzle 12 is varied corresponding to a combustion load, in order to assure stable burning of the fuel, and, to suppress radiant heat received by structures of the solid fuel burner and walls of the furnace.
摘要:
A solid fuel burner using a low oxygen concentration gas as a transporting gas of a low grade solid fuel such as brown coal or the like and a combustion method using the solid fuel burner are provided. The solid fuel burner comprises a means for accelerating ignition of the fuel and a means for preventing slugging caused by combustion ash from occurring. Mixing of fuel and air inside a fuel nozzle 11 is accelerated by that an additional air nozzle 12 and a separator 35 for separating a flow passage are arranged in the fuel nozzle 11, and the exit of the additional air nozzle 12 is set at a position so as to overlap with the separator 35 when seeing from a direction perpendicular to a burner axis, and additional air is ejected in a direction nearly perpendicular to a flow direction of a fuel jet flowing through the fuel nozzle 11. An amount of air from the additional air nozzle 12 is varied corresponding to a combustion load. By increasing the amount of air from the additional air nozzle 12 at a low load operation, an oxygen concentration of a circulation flow 19 formed in a downstream portion outside the exit of the fuel nozzle 11 is increased to stably burn the fuel. By decreasing the amount of air from the additional air nozzle 12 at a high load operation, a flame is formed at a position distant from the fuel nozzle 11 to suppress radiant heat received by structures of the solid fuel burner and walls of the furnace.
摘要:
According to a burner of the present invention, a stable combustion is obtained in a wide range from a high-load operation condition to a low-load operation condition even in the case of low quality solid fuel such as brown coal. The amount of air supplied from additional air holes or additional air nozzles 12 can be adjusted depending on the combustion load of furnace 41. At a low load, the amount of air supplied from additional air holes or additional air nozzles 12 is increased, whereby the oxygen concentration in a recirculation zones 19 formed downstream of the outside of a fuel nozzle 11 exit, permits a stable combustion. At a high load, the amount of air supplied from additional air holes or additional air nozzles 12 is reduced, whereby a flame is formed in a position far from the fuel nozzle 11. This suppresses thermal radiation onto a solid fuel burner 42 structure and a furnace 41 wall. The solid fuel burner 42 is applicable to combustion using low-quality solid fuel such as brown coal and exhaust gas as the carrier gas.
摘要:
A solid fuel burner using a low oxygen concentration gas as a transporting gas of a low grade solid fuel such as brown coal or the like and a combustion method using the solid fuel burner are provided. The solid fuel burner comprises a means for accelerating ignition of the fuel and a means for preventing slugging caused by combustion ash from occurring. Mixing of fuel and air inside a fuel nozzle 11 is accelerated by that an additional air nozzle 12 and a separator 35 for separating a flow passage are arranged in the fuel nozzle 11, and the exit of the additional air nozzle 12 is set at a position so as to overlap with the separator 35 when seeing from a direction perpendicular to a burner axis, and additional air is ejected in a direction nearly perpendicular to a flow direction of a fuel jet flowing through the fuel nozzle 11. An amount of air from the additional air nozzle 12 is varied corresponding to a combustion load. By increasing the amount of air from the additional air nozzle 12 at a low load operation, an oxygen concentration of a circulation flow 19 formed in a downstream portion outside the exit of the fuel nozzle 11 is increased to stably burn the fuel. By decreasing the amount of air from the additional air nozzle 12 at a high load operation, a flame is formed at a position distant from the fuel nozzle 11 to suppress radiant heat received by structures of the solid fuel burner and walls of the furnace.
摘要:
A overfiring air port of the present invention is to supply an incomplete combustion region with air making up for combustion-shortage, in a furnace in which the incomplete combustion region less than stoichiometric ratio is formed by a burner. Furthermore, the airport is characterized by comprising: a nozzle mechanism for injecting air including an axial velocity component of an air flow and a radial velocity component directed to a center line of the airport; and a control mechanism for controlling a ratio of these velocity components.
摘要:
A pulverized coal-fired boiler efficiently supplies air to a central part of a furnace and the neighborhood of a furnace wall, thereby promoting mixture with combustion gas, and reducing both NOx and CO.The main after air ports are structured so as to jet air having a large momentum for enabling arrival at the central part of the furnace, and the sub-after air ports are structured so as to jet air having a small momentum to the neighborhood of the wall face of the furnace, and a sectional center of each of the sub-after air ports is within a range from 1 to 5 times of a caliber of the main after air ports from a sectional center of each of the main after air ports.
摘要:
A solid-fuel burner comprising a fuel nozzle for injecting a mixed fluid with a mixture of solid fuel and air as a carrier gas thereof, a plurality of air nozzles provided on the outside of the fuel nozzle for surrounding the fuel nozzle; an end portion of an inner circumferential wall of the air nozzle located at least at the outermost circumference is outwardly expanded, and an inductive member provided at outlet of the air nozzle located at least on the outermost circumference so as to direct flow of air in the direction of outer circumference.
摘要:
A solid-fuel burner comprising a fuel nozzle for injecting a mixed fluid with a mixture of solid fuel and air as a carrier gas thereof, a plurality of air nozzles provided on the outside of the fuel nozzle for surrounding the fuel nozzle; an end portion of an inner circumferential wall of the air nozzle located at least at the outermost circumference is outwardly expanded, and an inductive member provided at outlet of the air nozzle located at least on the outermost circumference so as to direct flow of air in the direction of outer circumference.
摘要:
In a burner of construction having a primary nozzle, a secondary nozzle and a tertiary nozzle, a partition wall partitioning the secondary nozzle and the tertiary nozzle and having a flow path change member provided thereon, the partition wall is formed so as to be movable in parallel to the burner axis to control jetting speeds and flow rates of secondary air and tertiary air, whereby it is possible to cool the burner constituent members while reducing NOx. The partition wall is composed of a fixed wall and a movable wall. The burner comprises a bypass passage through which tertiary air in the tertiary nozzle bypasses the tertiary nozzle to flow into the secondary nozzle or the primary nozzle.