Abstract: An oxyfuel boiler system, comprising: an oxygen generator to separate oxygen from air; a coal supply unit to dry and pulverize coal; a burner having a fuel feed path for feeding pulverized coal supplied from the coal supply unit and an oxidizer feed path for feeding oxidizer; a boiler provided with the burner; an exhaust gas discharge line to discharge exhaust gas generated in the boiler into environment; an exhaust gas treatment apparatus provided in the exhaust gas discharge line, a CO2 separator provided downstream of the exhaust gas treatment apparatus in the exhaust gas discharge line to separate CO2 from the exhaust gas; an exhaust gas recirculation line including an exhaust gas tapping port provided in the exhaust gas discharge line to extract a part of the exhaust gas; and an oxygen supply line to supply the oxygen generated at the oxygen generator to the exhaust gas flowing through the exhaust gas recirculation line, wherein the exhaust gas treatment apparatus is provided with at least an SO3 removin

Abstract: 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.

Abstract: When at least one of a distribution of gas composition and distribution of temperature inside a furnace is estimated by dividing the region inside the furnace into two-dimensional or three-dimensional cells, and calculating a gas flow rate, a gas reaction amount, a coal combustion rate, a radiant heat transfer rate in each of the cells, based on design data including furnace dimentions and operational data including a coal supply rate and an air supply rate, an air ratio of gas phase--gas composion table is referred to, thereby to simplify the gas reaction amount calculation and reduce drastically time required for the calculation.