Oxyfuel combustion boiler plant and operation method of oxyfuel combustion boiler plant

摘要

An oxyfuel combustion boiler plant comprising: a boiler (200) having an air separation unit (360) for manufacturing oxygen by separating nitrogen from air, a burner (200) for burning the oxygen supplied from the air separation unit and pulverized coal, and a primary system pipe (216) for supplying the pulverized coal to the burner, exhaust gas recirculation system pipe (390) for supplying combustion exhaust gas discharged from the boiler to the primary system pipe, a carbon dioxide capture unit (350) for capturing carbon dioxide in the exhaust gas discharged from the boiler, the oxyfuel combustion boiler plant is further comprising: an oxygen buffer tank (132) disposed on a downstream side of the air separation unit (360); an oxygen supply pipe (219) for supplying oxygen to the primary system pipe (216) of the burner (210) from the oxygen buffer tank (132); and a nitrogen supply pipe (137) for supplying a part of nitrogen generated from the air separation unit (360) or an air supply pipe (138) for supplying air from outside which is connected to the oxygen supply pipe (219) on a downstream side of the oxygen buffer tank (132) and on an upstream side of a junction of the primary system pipe (216).