CN209819530U - Top negative pressure feeding mechanism for mixed combustion of coal slime and coal gangue in circulating fluidized bed - Google Patents

Abstract

The utility model provides a top negative pressure feed mechanism of coal slime and gangue co-combustion in circulating fluidized bed, including the gangue feed inlet, furnace, coal slime feed inlet, flue, exhaust port, separator, L valve and a wind import, the gangue feed inlet links to each other with the furnace downside, and the coal slime feed inlet links to each other with the furnace top, and furnace exit linkage flue import, flue top are equipped with the exhaust port, and the flue export links to each other with the separator import, and the separator export links to each other with the import of L valve, and the export of L valve links to each other with the furnace downside, and a wind import is connected to the furnace bottom. The application provides a feeding mechanism is through giving into the coal slime from the furnace top and giving into the mode that the gangue combined together from the furnace downside, can effectively improve fuel particle distribution homogeneity, improves fuel co-combustion intensity, improves furnace bed temperature and temperature distribution homogeneity for combustion stability and efficiency improve greatly, and can make the coal slime feed inlet be in under the negative pressure environment, and the fuel is difficult for leaking.

Description

Top negative pressure feeding mechanism for mixed combustion of coal slime and coal gangue in circulating fluidized bed

Technical Field

The utility model relates to a fuel combustion technology field of being inferior, concretely relates to top negative pressure feed mechanism of coal slime and gangue co-combustion in circulating fluidized bed.

Background

Because the inferior fuels such as coal gangue and the like are discharged by hundreds of millions of tons every year, the accumulated accumulation reaches more than 50 hundred millions of tons at present. The coal gangue occupies a large amount of land due to long-term stockpiling, and occupies 1.2 ten thousand hectares and is still increased. Coal gangue and the like are extremely easy to self-ignite and discharge a large amount of harmful gas, so that the utilization of inferior fuels such as coal gangue and the like brings huge economic and social benefits. The circulating fluidized bed technology has the advantages of wide fuel adaptability, high section heat intensity, less pollutant discharge, good boiler load adaptability and the like, is a novel mature high-efficiency low-pollution clean coal technology, and is very suitable for burning inferior fuels such as coal gangue and the like.

And the inventor of the utility model discovers through research that when burning poor fuel such as high moisture (> 25%), high ash content (> 75%), extremely low calorific value (<4500kJ/kg) gangue, the design reason because the fuel feeding position often can appear not easily catching fire to the circulating fluidized bed boiler of coal burning at present, and the boiler bed is warm low, the unstable problem that with combustion efficiency hangs down.

SUMMERY OF THE UTILITY MODEL

When changing into inferior fuel such as burning the gangue to current circulating fluidized bed boiler, because the design reason of fuel feeding position, often can appear difficult catching fire, boiler bed temperature is low, technical problem that the burning is unstable and combustion efficiency is low, the utility model provides a top negative pressure feed mechanism that coal slime and gangue co-combustion in circulating fluidized bed.

In order to solve the technical problem, the utility model discloses a following technical scheme:

the utility model provides a top negative pressure feed mechanism of coal slime and gangue co-combustion in circulating fluidized bed, includes gangue feed inlet, furnace, coal slime feed inlet, flue, exhaust port, separator, L valve and a wind import, the gangue feed inlet links to each other with the furnace downside, the coal slime feed inlet links to each other with the furnace top, furnace exit linkage flue import, the flue top is equipped with the exhaust port, the flue export links to each other with the separator import, the separator export links to each other with the import of L valve, the export of L valve links to each other with the furnace downside, a wind import is connected to the furnace bottom.

Compared with the prior art, the utility model provides a top negative pressure feed mechanism of coal slime and gangue co-combustion in circulating fluidized bed for acting on mix the coal fired circulating fluidized bed boiler who burns high moisture (> 25%), high ash content (> 75%), extremely low calorific value (<4500kJ/kg) gangue. In the working process, coal slime enters from the top of a hearth through a coal slime feeding port, the lumpy coal slime falls under the action of gravity, the outside of the coal slime is hardened firstly after heat is absorbed in the falling process, then the coal slime is cracked due to evaporation of internal water, the coal slime is further reduced in size and repeated, and when the coal slime reaches the bottom of the hearth, the coal slime becomes fine; the gangue gets into from the furnace downside through the gangue feed inlet, a wind that the import of wind got into bottom the furnace blows down, move to furnace upper portion, reach two kinds of fuel co-combustion in furnace, when a wind speed is different, can influence the distribution of interior fuel particle and oxygen of stove, thereby influence co-combustion intensity, make the temperature size and the distribution in the stove different, combustion stability and efficiency also can be different, when a wind speed is about 3 ms through simulation and experimental study, circulating fluidized bed is in the bed state at a slow speed, fuel particle concentration distributes evenly, oxygen concentration is more even lower, co-combustion intensity is higher, combustion efficiency is higher. Therefore, the feeding mechanism can effectively improve the distribution uniformity of fuel particles, improve the mixed combustion strength of the fuel, and improve the bed temperature and the temperature distribution uniformity of the hearth by combining the mode of feeding the coal slime from the top of the hearth and feeding the coal gangue from the lower side of the hearth, so that the combustion stability and the combustion efficiency are greatly improved; and the draught fan connected with the tail of the existing circulating fluidized bed boiler is used for extracting air in the boiler, so that the coal slime feeding port is in a negative pressure environment, and fuel is not easy to leak.

Furthermore, the coal slime is fed in from the position that is close to the left side in furnace top through the coal slime feed inlet by the coal slime pump, the coal gangue is fed in from the fluidized bed dense phase district of furnace downside by the batcher through the coal gangue feed inlet.

Further, the coal gangue fed from the coal gangue feeding port and the coal slime fed from the coal slime feeding port have a mass ratio of 7: 3.

drawings

FIG. 1 is a schematic view of the top negative pressure feeding mechanism for co-combustion of coal slime and coal gangue in the circulating fluidized bed.

In the figure, 1, a coal gangue feeding port; 2. a hearth; 3. a coal slurry feeding port; 4. a flue; 5. a smoke outlet; 6. a separator; 7. an L valve; 8. a primary air inlet.

Detailed Description

In order to make the technical means, creation features, achievement purposes and functions of the present invention easy to understand and understand, the present invention is further explained by combining with the specific drawings.

In the description of the present invention, it is to be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "outlet", "inlet", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used only for convenience of description and for simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted", "provided", "connected" and "connected" are to be interpreted broadly, for example, as being either fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1, the utility model provides a top negative pressure feeding mechanism for co-combustion of coal slime and coal gangue in a circulating fluidized bed, which comprises a coal gangue feed port 1, a hearth 2, a coal slime feed port 3, a flue 4, a smoke vent 5, a separator 6, an L valve 7 and a primary air inlet 8, wherein the coal gangue feed port 1 is connected with the lower side of the hearth 2, the coal slime feed port 3 is connected with the top of the hearth 2, the outlet of the hearth 2 is connected with the inlet of the flue 4, the top of the flue 4 is provided with the smoke vent 5, the outlet of the flue 4 is connected with the inlet of the separator 6, the outlet of the separator 6 is connected with the inlet of the L valve 7, namely, the flue gas combusted in the hearth 2 flows into the separator 6 after passing through the flue 4, the separator 6 separates out solid particles in the flue gas, the separated solid particles return to the hearth 2 through the L valve 7 for circulation, the outlet of the L valve 7 is connected with the, the bottom of the hearth 2 is connected with a primary air inlet 8.

Compared with the prior art, the utility model provides a top negative pressure feed mechanism of coal slime and gangue co-combustion in circulating fluidized bed for acting on mix the coal fired circulating fluidized bed boiler who burns high moisture (> 25%), high ash content (> 75%), extremely low calorific value (<4500kJ/kg) gangue. In the working process, coal slime enters from the top of a hearth through a coal slime feeding port, the lumpy coal slime falls under the action of gravity, the outside of the coal slime is hardened firstly after heat is absorbed in the falling process, then the coal slime is cracked due to evaporation of internal water, the coal slime is further reduced in size and repeated, and when the coal slime reaches the bottom of the hearth, the coal slime becomes fine; the gangue gets into from the furnace downside through the gangue feed inlet, a wind that the import of wind got into bottom the furnace blows down, move to furnace upper portion, reach two kinds of fuel co-combustion in furnace, when a wind speed is different, can influence the distribution of interior fuel particle and oxygen of stove, thereby influence co-combustion intensity, make the temperature size and the distribution in the stove different, combustion stability and efficiency also can be different, when a wind speed is about 3 ms through simulation and experimental study, circulating fluidized bed is in the bed state at a slow speed, fuel particle concentration distributes evenly, oxygen concentration is more even lower, co-combustion intensity is higher, combustion efficiency is higher. Therefore, the feeding mechanism can effectively improve the distribution uniformity of fuel particles, improve the mixed combustion strength of the fuel, and improve the bed temperature and the temperature distribution uniformity of the hearth by combining the mode of feeding the coal slime from the top of the hearth and feeding the coal gangue from the lower side of the hearth, so that the combustion stability and the combustion efficiency are greatly improved; and the draught fan connected with the tail of the existing circulating fluidized bed boiler is used for extracting air in the boiler, so that the coal slime feeding port is in a negative pressure environment, and fuel is not easy to leak.

As a specific embodiment, the coal slime is fed from the position close to the left side of the top of a hearth 2 through an existing coal slime pump through a coal slime feeding port 3, and the coal gangue is fed from a dense-phase area of a fluidized bed at the lower side of the hearth 2 through an existing feeder through a coal gangue feeding port 1, so that the coal slime can be thermally exploded in the descending process, and coal slime lumps are refined while water is reduced; the dense phase zone has high heat capacity, the fuel is heated and combusted quickly, the residence time is long, the combustion is sufficient, and the combination of the two can ensure that the fuel is distributed more uniformly and the combustion is more sufficient. Of course, other methods known in the art can be used to feed the coal slurry and coal gangue.

As a specific embodiment, the inventor of the present application finds, through research, that when the mass ratio of the coal gangue to the coal slime is different, the temperature and distribution in the furnace 2 will be different; through simulation and experimental research, when the coal gangue and coal slime co-combustion mass ratio is 7 by utilizing the feeding mechanism: 3, namely, the mass ratio of the coal gangue fed from the coal gangue feeding port 1 to the coal slime fed from the coal slime feeding port 3 is 7: and 3, the temperature in the hearth 2 is obviously increased, and the temperature distribution is more uniform.

As a specific embodiment, the circulating fluidized bed adopts the existing DG35-3.82/450 type circulating fluidized bed boiler, when high-moisture, high-ash and low-calorific-value coal gangue is mixed and burned in the circulating fluidized bed, the problems of high incomplete combustion loss, high smoke discharge loss and poor adaptability to low-calorific-value fuel can occur, and the combustion performance of the circulating fluidized bed is remarkably improved after the feeding mechanism provided by the application is adopted to act with the circulating fluidized bed. Of course, on the basis of the circulating fluidized bed boiler with the type described above, the skilled person in the art can also apply the feeding mechanism provided by the present application to the circulating fluidized bed boiler with the speed of 10 to 420t/h to improve the combustion performance, that is, the feeding mechanism is suitable for the circulating fluidized bed boiler with the speed of 10 to 420 t/h.

Finally, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the present invention can be modified or replaced by other means without departing from the spirit and scope of the present invention, which should be construed as limited only by the appended claims.

Claims (3)

1. The top negative pressure feeding mechanism for co-combustion of coal slime and coal gangue in a circulating fluidized bed is characterized by comprising a coal gangue feeding port (1), a hearth (2), a coal slime feeding port (3), a flue (4), a smoke exhaust port (5), a separator (6), an L valve (7) and a primary air inlet (8), the coal gangue feeding port (1) is connected with the lower side of the hearth (2), the coal slime feeding port (3) is connected with the top of the hearth (2), the outlet of the hearth (2) is connected with the inlet of a flue (4), the top of the flue (4) is provided with a smoke outlet (5), the outlet of the flue (4) is connected with the inlet of a separator (6), the outlet of the separator (6) is connected with the inlet of an L valve (7), an outlet of the L valve (7) is connected with the lower side of the hearth (2), and the bottom of the hearth (2) is connected with a primary air inlet (8).

2. The top negative pressure feeding mechanism for co-combustion of coal slime and coal gangue in the circulating fluidized bed according to claim 1, wherein the coal slime is fed from the top of the hearth (2) near the left side through a coal slime feeding port (3) by a coal slime pump, and the coal gangue is fed from the dense phase zone of the fluidized bed at the lower side of the hearth (2) through a coal gangue feeding port (1) by a coal feeder.

3. The top negative pressure feeding mechanism for co-combustion of coal slime and coal gangue in a circulating fluidized bed according to claim 1 or 2, wherein the mass ratio of the coal gangue fed from the coal gangue feeding port (1) to the coal slime fed from the coal slime feeding port (3) is 7: 3.