Circulated fluid bed boiler and tangential firing method

Abstract

The invention involves a circulating fluidized bed boiler and its circle of contact burning method, the boiler consists essentially of boiler body and wind-forming plate, the wind-forming plate is installed below the boiler body, its structural characteristics are: two or more sets of injector device are installed below the dense phase area of boiler body, each set of injector device consists of four injectors which are both installed on the four corners of boiler body horizontal section separately, the injectors of bottom injector device are installed horizontally, and the injector device in other layers inclined toward down 5: . In the same horizontal surface, the central line of one unit injectors installed on four corners forms a circle of contact in the furnace tank, and the secondary wind or steam ejected out each injector device form a circle of contact air flow. The invention has the advantages of reasonable structural design, adequate fuel combustion, coal-saving, efficient, effective oxygen supplementary capacity improving through second wind energy, higher filling degree of furnace tank and full fuel combustion.

Description

technical field [0001] The invention relates to a circulating fluidized bed boiler and a tangential combustion method thereof, which is suitable for the circulating fluidized bed boiler and improves the combustion efficiency of the boiler. Background technique [0002] More and more circulating fluidized bed boilers in domestic power plants are put into operation, and the capacity is getting bigger and bigger. 300MW units of circulating fluidized bed boilers have been put into operation. The combustion organization of circulating fluidized bed boilers is usually : The primary air is used as the fluidizing air to ensure the fluidization of the boiler bed material, and it is sent into the furnace from under the air distribution plate; the secondary air is used as the combustion distribution air to be sent into the furnace from the dilute phase area. Most of the secondary air is added in a radial manner. The experimental research data show that due to the insufficient penetrati...

AI Technical Summary

Problems solved by technology

This will cause the carbon particles to be partially deficient in oxygen in the furnace, so that the carbon contained in the fly ash cannot be burned out; in addition, due to the low design combustion temperature of the circulating fluidized bed boiler, the large amount of circulating ash and the limitation of the efficiency of the separator, resulting in The fly ash combustible content of circulating fluidized bed boilers is relatively high, which is 4-5 times that of pulverized coal boilers. Especially when anthracite is used, the combustible content of boiler fly ash is as high as about 15%, which seriously affects the efficiency of the unit and restricts Further Popularization of Circulating Fluidized Bed Boiler Units

Moreover, the larger the boiler capacity and the larger the furnace volume, the more difficult it is to control the carbon content of fly ash

At present, the circulating fluidized bed boilers produced and put into operation in China still have the following problems: 1. The particle size of the coal is relatively large, and it takes a long time to burn the carbon in the fly ash; 2. The temperature of the furnace is lower than that of the pulverized coal furnace. 3. The ash separator dedicated to circulating fluidized bed boilers is difficult to capture a large amount of fly ash with a particle size of 0.030-0.090mm, and this size range The carbon ash often cannot be burned within a cycle time, therefore, the fly ash combustible content of the circulating fluidized bed boiler is relatively high

This is the main reason why the thermal efficiency of most circulating fluidized bed boilers is low or even fails to reach the design efficiency, and as the boiler capacity increases, the influence of the secondary air on the combustion conditions in the furnace will also increase

Images