A combined combustion burner and a combustion apparatus including the combined combustion burner. The combined combustion burner may include a center tube forming a center passage configured to supply cooling air, a fuel tube surrounding the center tube and forming a fuel passage through which premixed fuel mixed with solid fuel and primary air is sprayed, a secondary tube surrounding the fuel tube and forming a secondary passage through which secondary air is sprayed, and an additional spray nozzle inserted inside the center tube and configured to spray auxiliary fuel containing ammonia.

The burner device for high-temperature air combustion according to the present invention is equipped with a thermal insulation portion (5) that is provided facing a furnace (1) and has a throat (6); a burner nozzle (9) that is provided at the axial center of this throat and that injects a pulverized coal mixed flow (38) into the furnace through the throat; a windbox (8) that is provided so as to house this burner nozzle; an air register (16) that is provided at the distal end of the burner nozzle and that injects low-temperature secondary air from the windbox to the throat; a high-temperature air nozzle (23), one end of which opens into the furnace through the heat insulation portion; and a combustion air switching means (16, 24) that switches between injecting low-temperature secondary air to the throat through the air register and injecting high-temperature secondary air to the furnace interior through the high-temperature air nozzle, in which in steady combustion, low-temperature secondary air is injected to the throat through the air register by the combustion air switching means and a pulverized coal mixed flow is injected from the burner nozzle, and in high-temperature air combustion, high-temperature secondary air is injected to the furnace interior through the high-temperature air nozzle by the combustion air switching means and a pulverized coal mixed flow is injected from the burner nozzle.

The burner device for high-temperature air combustion according to the present invention is equipped with a thermal insulation portion (5) that is provided facing a furnace (1) and has a throat (6); a burner nozzle (9) that is provided at the axial center of this throat and that injects a pulverized coal mixed flow (38) into the furnace through the throat; a windbox (8) that is provided so as to house this burner nozzle; an air register (16) that is provided at the distal end of the burner nozzle and that injects low-temperature secondary air from the windbox to the throat; a high-temperature air nozzle (23), one end of which opens into the furnace through the heat insulation portion; and a combustion air switching means (16, 24) that switches between injecting low-temperature secondary air to the throat through the air register and injecting high-temperature secondary air to the furnace interior through the high-temperature air nozzle, in which in steady combustion, low-temperature secondary air is injected to the throat through the air register by the combustion air switching means and a pulverized coal mixed flow is injected from the burner nozzle, and in high-temperature air combustion, high-temperature secondary air is injected to the furnace interior through the high-temperature air nozzle by the combustion air switching means and a pulverized coal mixed flow is injected from the burner nozzle.

An oil-fired burner (30A) for warming, disposed adjacent to the outer periphery of a pulverized coal burner which inputs pulverized coal and air into a furnace, includes: an oil gun (32) for inputting an oil fuel disposed at the center of an outlet opening of a nozzle main body (31) substantially rectangular in cross-section; and a secondary air input port (40) disposed so as to surround the outer periphery of the oil gun (32), wherein the secondary air input port (40) is constituted of: a central arc section (41) substantially similar in shape to a circular diffuser (34) mounted on the leading end side of the oil gun (32); and rectangular sections (42L, 42R) provided continuously from both sides of the central arc section (41) and narrowed in face-to-face dimension in the direction of the adjacent pulverized coal burners so as to increase the distance from them.

An oil-fired burner (30A) for warming, disposed adjacent to the outer periphery of a pulverized coal burner which inputs pulverized coal and air into a furnace, includes: an oil gun (32) for inputting an oil fuel disposed at the center of an outlet opening of a nozzle main body (31) substantially rectangular in cross-section; and a secondary air input port (40) disposed so as to surround the outer periphery of the oil gun (32), wherein the secondary air input port (40) is constituted of: a central arc section (41) substantially similar in shape to a circular diffuser (34) mounted on the leading end side of the oil gun (32); and rectangular sections (42L, 42R) provided continuously from both sides of the central arc section (41) and narrowed in face-to-face dimension in the direction of the adjacent pulverized coal burners so as to increase the distance from them.

A combustion system with a combustion area in a boiler including a fuel pipe for delivering fuel is disclosed. A duct having a bend extended there through is in fluid communication with the fuel pipe and the combustion area of the boiler. The duct has an outer perimeter and an inner perimeter. The duct includes a first partition plate to form a first parallel flow of the fuel between the outer perimeter and the first partition plate, upstream of the bend.

A combustion system with a combustion area in a boiler including a fuel pipe for delivering fuel is disclosed. A duct having a bend extended there through is in fluid communication with the fuel pipe and the combustion area of the boiler. The duct has an outer perimeter and an inner perimeter. The duct includes a first partition plate to form a first parallel flow of the fuel between the outer perimeter and the first partition plate, upstream of the bend.