| 摘要 |
PURPOSE:To decrease NOX by providing an oxygen separator which supplies oxygen-enriched air to a densely fluidized bed and oxygen-reduced air to a sparsely fluidized bed in a coal burning fluidized bed boiler. CONSTITUTION:Oxygen-enriched air separated by an oxygen separator 15 which uses silicone composite membrane module is made to communicate with a sparsely fluidized bed 4 and an air disperser 3 via an air preheater 12 and valves 27, 28 through a line 8, while oxygen-reduced air separated by said oxygen separator 15 is in communication with the lower part of a densely fluidized bed 2 via a line 17 and is also in communication with lines 19, 21. In this constitution, the valves 27-30 are properly adjusted, and thereby the amounts of the oxygen-enriched air and the oxygen-reduced air relative to the densely fluidized bed 2 and the sparsely fluidized bed 4 are regulated according to an operational condition to control NOX and temperatures. By providing the densely fluidized bed in a state of deficient oxygen and the sparsely fluidized bed in a state of excessive oxygen, a two-step combustion method is realized to enable NOX to be decreased. |
