Provided are a pulverized coal boiler with a bottom combustor, and a control method for the pulverized coal boiler, wherein the pulverized coal boiler includes a furnace, at least one bottom combustor and a secondary air distributing device. Each combustor is provided with a combustor spout, and the secondary air distributing device surrounds the combustor and is arranged at the bottom of the furnace. The secondary air distributing device includes an internal secondary air distributing device and an external secondary air distributing device, wherein the internal secondary air distributing device includes an internal secondary air gathering box and an internal secondary air pipe, and the external secondary air distributing device includes an external secondary air gathering box and an external secondary air pipe.

A method for operating a combustion chamber is provided. The method includes introducing a fuel into the combustion chamber via a plurality of nozzles, each nozzle having an associated stoichiometry for an output end of the nozzle. The method further includes measuring the stoichiometry of each nozzle via one or more sensors to obtain stoichiometric data, and determining that at least one of a frequency and an amplitude of spectral line fluctuations derived from the stoichiometric data has exceeded a threshold. The method further includes adjusting the stoichiometry of at least one of the nozzles based at least in part on the stoichiometric data so as to maintain a flame stability of the combustion chamber.

A supercritical CO.sub.2 boiler capable of realizing uniform combustion, corrosion resistance and coking resistance, and a boiler system are provided. The supercritical CO.sub.2 boiler includes a main combustion chamber, an upper furnace, a furnace arch and a flue, wherein a cross section of the main combustion chamber is circular or oval, or is of an N-sided shape, where N>4; at least four burner groups are disposed on the main combustion chamber, each group of burner nozzles corresponding to each burner group includes a recirculating air nozzle, a primary air nozzle and a secondary air nozzle; lateral recirculating air nozzles symmetrically distributed are respectively disposed at two sides of the primary air nozzle, the recirculating air nozzle and the lateral recirculating air nozzle are configured to feed recirculating flue gas or a mixed gas of the recirculating flue gas and secondary air into the main combustion chamber.

A supercritical CO.sub.2 boiler capable of realizing uniform combustion, corrosion resistance and coking resistance, and a boiler system are provided. The supercritical CO.sub.2 boiler includes a main combustion chamber, an upper furnace, a furnace arch and a flue, wherein a cross section of the main combustion chamber is circular or oval, or is of an N-sided shape, where N>4; at least four burner groups are disposed on the main combustion chamber, each group of burner nozzles corresponding to each burner group includes a recirculating air nozzle, a primary air nozzle and a secondary air nozzle; lateral recirculating air nozzles symmetrically distributed are respectively disposed at two sides of the primary air nozzle, the recirculating air nozzle and the lateral recirculating air nozzle are configured to feed recirculating flue gas or a mixed gas of the recirculating flue gas and secondary air into the main combustion chamber.

A combustion burner including: a fuel nozzle (61) which ejects a fuel gas that is a mixture of fuel and air; a combustion air nozzle (62) which ejects air from an outer side of the fuel nozzle (61); first members (71) which are arranged inside the fuel nozzle (61) and which each comprise a first inclined surface (82a) inclined with respect to the flow of the fuel gas, and a first inclination end edge where the inclination of the first inclined surface (82a) ends; and second members (72) which are arranged downstream of the first inclination end edges in the direction of fuel gas flow, and which each comprise a second inclined surface (84a) inclined towards the first members (71) with respect to the fuel gas flow and a second inclination end edge where the inclination of the second inclined surface (84a) ends.

A method for operating a combustion chamber is provided. The method includes introducing a fuel into the combustion chamber via a plurality of nozzles, each nozzle having an associated stoichiometry for an output end of the nozzle. The method further includes measuring the stoichiometry of each nozzle via one or more sensors to obtain stoichiometric data, and determining that at least one of a frequency and an amplitude of spectral line fluctuations derived from the stoichiometric data has exceeded a threshold. The method further includes adjusting the stoichiometry of at least one of the nozzles based at least in part on the stoichiometric data so as to maintain a flame stability of the combustion chamber.

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.

Provided is a combustion burner including: a fuel nozzle (61) which ejects a fuel gas that is a mixture of fuel and air; a combustion air nozzle (62) which ejects air from an outer side of the fuel nozzle (61); first members (71) which are arranged inside the fuel nozzle (61) and which each comprise a first inclined surface (82a) inclined with respect to the flow of the fuel gas, and a first inclination end edge where the inclination of the first inclined surface (82a) ends; and second members (72) which are arranged downstream of the first inclination end edges in the direction of fuel gas flow, and which each comprise a second inclined surface (84a) inclined towards the first members (71) with respect to the fuel gas flow and a second inclination end edge where the inclination of the second inclined surface (84a) ends.

Disclosed herein is a method of controlling the operation of an oxy-fired boiler; the method comprising combusting a fuel in a boiler; producing a heat absorption pattern in the boiler; discharging flue gases from the boiler; recycling a portion of the flue gases to the boiler; combining a first oxidant stream with the recycled flue gases to form a combined stream; splitting the combined stream into several fractions; and introducing each fraction of the combined stream to the boiler at different points of entry to the boiler.

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.