Abstract: The present disclosure provides a method for distributing gas for oxy-fuel combustion on a circulating fluidized bed. In the method, the gas is provided by three stages into a furnace of the circulating fluidized bed. The method includes: blowing in a first-stage gas containing oxygen and recycled flue gas from the bottom of the furnace; blowing in a second-stage gas containing recycled flue gas from a transition zone between a dense-phase zone and a dilute-phase zone of the furnace; and blowing in a third-stage gas containing oxygen from a side wall of the furnace.

Abstract: A circulating fluidized bed boiler is disclosed.

Abstract: A water-cooling U-valve is composed of a downcomer (1), a riser (2), and a return chute (3), which are sequentially connected. An intermediate partition (4) is disposed between the downcomer (1) and the riser (2), the lower parts of the downcomer (1) and the riser (2) are interconnected. A material returning partition (5) is disposed between the riser (2) and the return chute (3), the upper parts of the riser (2) and the return chute (3) are interconnected. The casing of U-valve comprises membrane walls, the inside of the membrane walls are laid with refractory. Some water-cooling tubes of the membrane walls extend into the inside of the U-valve, forming the water cooing intermediate partition (4) and material returning partition (5). The headers (40, 50) are connected with the headers (33, 13) formed by some water-cooling tubes of membrane walls by connecting tubes (7, 8).

Abstract: The present disclosure provides a method for distributing gas for oxy-fuel combustion on a circulating fluidized bed. In the method, the gas is provided by three stages into a furnace of the circulating fluidized bed. The method includes: blowing in a first-stage gas containing oxygen and recycled flue gas from the bottom of the furnace; blowing in a second-stage gas containing recycled flue gas from a transition zone between a dense-phase zone and a dilute-phase zone of the furnace; and blowing in a third-stage gas containing oxygen from a side wall of the furnace.

Abstract: A circulating fluidized bed boiler is disclosed.

Abstract: Water-cooling U-valve is composed of a downcomer (1), a riser (2), and a return chute (3), which are sequentially connected. An intermediate partition (4) is disposed between the downcomer (1) and the riser (2), the lower parts of which are interconnected. A material returning partition (5) is disposed between the riser (2) and the return chute (3), the upper parts of which are interconnected. The casing of U-valve is membrane walls, the inside of which are laid with refractory. Some water-cooling tubes of the membrane walls extend into the inside of the U-valve, forming the water cooing intermediate partition (4) and material returning partition (5). There are headers (40, 50) for both the intermediate partition (4) and the material returning partition (5), and the headers (40, 50) are connected with the headers (33, 13) formed by some water-cooling tubes of membrane walls by connecting tubes (7, 8).