Boiler cooling air chamber and isobaric device manufacturing method

Abstract

The invention discloses a boiler cooling air chamber and an isobaric device manufacturing method, and relates to the field of thermal power plant boilers, and the boiler cooling air chamber comprises an air chamber main body, an air distribution plate and an isobaric device; the air chamber body is divided into three sections communicated with one another in the length direction, isobaric devices are arranged at the two ends of the middle section in the length direction respectively, and air inlets communicated with the two side sections of the air chamber body are formed in the two ends of the air chamber body in the length direction respectively. And the isobaric device is provided with an air inlet rebound structure. The air distribution device has the advantages that the air distribution uniformity is improved, the problems of uneven bed temperature distribution, uneven material fluidization and the like in the prior art are solved, the minimum primary fluidization air volume is reduced, and then the bed temperature stability of the boiler during deep peak regulation is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of thermal power plant boilers, and in particular to a method for manufacturing a boiler cooling air chamber and an isobaric device. Background Art

[0002] Circulating fluidized bed (CFB) combustion technology is a new type of clean coal combustion technology, and its main feature is that the fuel is burned in a fluidized state in the furnace. The fuel is fed into the furnace by a coal feeding device, and is carried out of the bottom of the furnace under the action of high-pressure primary air for material circulation, and participates in combustion and heat transfer during the circulation process. Circulating fluidized bed boilers generally use cooling air chambers to provide high-pressure primary air to the furnace through air distribution plates, such as a wind chamber and circulating fluidized bed boiler disclosed in the patent document with publication number CN114294646A. With the large-scale development of circulating fluidized boiler technology, the cross-section of the boiler furnace has also increased. The high-pressure primary air provided by the existing boiler cooling air chamber has a large difference in flow distribution on the larger air distribution plate cross-section, and the air distribution uniformity is poor, which has a great impact on the important operating characteristics of the boiler, such as material circulation, air volume distribution, and bed temperature distribution. Summary of the invention

[0003] The technical problem to be solved by the present invention is how to improve the uniformity of air distribution in a boiler cooling air chamber.

[0004] The present invention solves the above technical problems through the following technical means: a boiler cooling air chamber, including an air chamber body, an air distribution plate and an isobaric device; the air chamber body is divided into three sections connected to each other along the length direction, and isobaric devices are respectively provided at both ends of the length direction of the middle section, and air inlets connected to its two side sections are respectively provided at both ends of the length direction of the air chamber body; the isobaric device is provided with an air inlet rebound structure. After entering from the air inlet, the primary air acts on the air inlet rebound structure and is rebounded to both sides to increase the primary air volume on both sides of the length direction of the air distribution plate, thereby increasing the fluidizing air volume on both sides of the length direction of the furnace, improving the uniformity of air distribution, overcoming the problems of uneven bed temperature distribution and uneven material fluidization in the prior art, reducing the minimum primary fluidizing air volume, thereby ensuring the bed temperature stability of the boiler during deep peak regulation.

[0005] As an optimized technical solution, the bottom of the air chamber body is symmetrically inclined from both sides in the width direction to the middle, and the middle position is lower than the two sides. The inclined setting of the bottom of the air chamber body on both sides can balance the air flow distribution in the width direction of the furnace, further improving the uniformity of air distribution.

[0006] As an optimized technical solution, the angle between the inclined parts on both sides of the bottom of the air chamber body and the horizontal plane is 10° to 15°.

[0007] As an optimized technical solution, the isobaric device includes an inclined plate, which is inclined from the lower part of the two side sections to the upper part of the middle section. After the primary wind enters, it rebounds obliquely upward and has a good effect of diffusing to both sides.

[0008] As an optimized technical solution, the angle between the inclined plate and the horizontal plane is 20° to 30°.

[0009] As an optimized technical solution, the isobaric device further includes a vertical plate, which is vertically arranged, the upper end of which is fixedly connected to the upper end of the inclined plate, the lower end of which is fixedly connected to the bottom of the air chamber body, and the two sides of the inclined plate in the width direction are respectively fixedly connected to the air chamber body, thereby ensuring structural stability.

[0010] As an optimized technical solution, there is a gap between the upper edge of the inclined plate and the air distribution plate, there is a gap between the lower edge of the inclined plate and the bottom of the air chamber body, and an opening is provided at the middle of the bottom of the vertical plate. The upper and lower gaps of the inclined plate and the opening at the bottom of the vertical plate enable the three sections of the air chamber body to be connected to each other from top to bottom.

[0011] As an optimized technical solution, the total length of the isobaric device is less than or equal to one third of the total length of the wind chamber body, which will not affect the primary air volume of the boiler.

[0012] As an optimized technical solution, a plurality of wind hoods are evenly distributed on the air distribution plate.

[0013] The present invention also discloses a method for manufacturing an isobaric device, which is used to manufacture an isobaric device in a boiler cooling air chamber described in any of the above schemes, comprising the following steps:

[0014] Step 1, making an isobaric device frame;

[0015] Step 2: Formwork;

[0016] Step three, add plastic and pound into shape.

[0017] The advantages of the present invention are:

[0018] 1. After entering the air inlet, the primary air acts on the air inlet rebound structure and is rebounded to both sides, increasing the primary air volume on both sides of the length direction of the air distribution plate, thereby increasing the fluidizing air volume on both sides of the length direction of the furnace, improving the uniformity of air distribution, overcoming the problems of uneven bed temperature distribution and uneven material fluidization in the prior art, reducing the minimum primary fluidizing air volume, and thus ensuring the bed temperature stability of the boiler during deep peak regulation.

[0019] 2. The inclined settings on both sides of the bottom of the air chamber body can balance the air flow distribution in the width direction of the furnace, further improving the uniformity of air distribution.

[0020] 3. The total length of the isobaric device is less than or equal to one third of the total length of the wind chamber body and will not affect the primary air volume of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a boiler cooling air chamber installed at the lower end of a furnace according to an embodiment of the present invention.

[0022] Figure 2 It is a schematic diagram of a boiler cooling air chamber installed at the lower end of a furnace in an embodiment of the present invention, cut in half along the width direction.

[0023] Figure 3 It is a schematic diagram of a boiler cooling air chamber installed at the lower end of a furnace in an embodiment of the present invention, cut in half along the length direction.

[0024] Figure 4 It is a schematic diagram of a boiler cooling air chamber cut along the height direction according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] like Figures 1 to 4 As shown, an embodiment of the present invention discloses a boiler cooling air chamber, which is installed at the lower end of a furnace 4 and includes an air chamber body 1, an air distribution plate 2 and an isobaric device 3.

[0027] A wind distribution plate 2 is arranged on the top of the wind chamber main body 1, and a plurality of wind hoods are evenly distributed on the wind distribution plate 2. The wind chamber main body 1 is connected to the furnace 4 through the wind distribution plate 2; the wind chamber main body 1 is divided into three sections which are connected to each other along the length direction, and isobaric devices 3 are respectively arranged at both ends of the length direction of the middle section, and air inlets which are connected to its two side sections are respectively arranged at both ends of the length direction of the wind chamber main body 1; the isobaric device 3 is provided with an air inlet rebound structure, and the primary air acts on the air inlet rebound structure after entering from the air inlet, and is rebounded to both sides and diffused, thereby increasing the primary air volume on both sides of the length direction of the wind distribution plate 2, and then increasing the fluidizing air volume on both sides of the length direction of the furnace 4, thereby improving the uniformity of air distribution, overcoming the problems of uneven bed temperature distribution and uneven material fluidization in the prior art, reducing the minimum primary fluidizing air volume, and then ensuring the bed temperature stability of the boiler during deep peak regulation.

[0028] The bottom of the wind chamber body 1 is symmetrically inclined from both sides in the width direction to the middle, and the middle position is lower than the two sides; the angle between the inclined parts on both sides of the bottom of the wind chamber body 1 and the horizontal plane is 10°~15°. The inclined settings on both sides of the bottom of the wind chamber body 1 can balance the air flow distribution in the width direction of the furnace 4, further improving the uniformity of air distribution.

[0029] The isobaric device 3 includes an inclined plate 31 and a vertical plate 32; the inclined plate 31 serves as an air inlet rebound structure, and is inclined from the lower part of the two side sections to the upper part of the middle section, and the angle between the inclined plate 31 and the horizontal plane is 20°~30°, and the two sides of the width direction of the inclined plate 31 are respectively fixedly connected to the air chamber main body 1; the vertical plate 32 is vertically arranged, the upper end of the vertical plate 32 is fixedly connected to the upper end of the inclined plate 31, and the lower end of the vertical plate 32 is fixedly connected to the bottom of the air chamber main body 1; there is a gap between the upper edge of the inclined plate 31 and the air distribution plate 2, and there is a triangular gap between the lower edge of the inclined plate 31 and the inclined parts on both sides of the bottom of the air chamber main body 1, and a rectangular opening is provided in the middle position of the bottom of the vertical plate 32, and the upper and lower gaps of the inclined plate 31 and the opening at the bottom of the vertical plate 32 are used to realize the upper and lower interconnection between the three sections of the air chamber main body 1.

[0030] The total length of the isobaric device 3 is less than or equal to one third of the total length of the wind chamber body 1, and will not affect the primary air volume of the boiler. In this embodiment, the lengths of the two side sections of the wind chamber body 1 are each one sixth of its total length, and the length of the middle section is one third of its total length. The lengths of the two isobaric devices 3 are each one sixth of the total length of the wind chamber body 1.

[0031] The present invention also discloses a method for manufacturing an isobaric device, which is used to manufacture an isobaric device 3 in a boiler cooling air chamber described in any of the above schemes, comprising the following steps:

[0032] Step 1: Make an isobaric device frame.

[0033] Use heat-resistant steel pipes to build a triangular frame according to the requirements of the drawings, lay heat-resistant steel bars on the frame, and weld anchors on the heat-resistant steel bars. After welding, grind and clean the welding slag according to the welding specifications, and then check the welding strength of each anchor one by one by hammering or manual bending. After the inspection, brush asphalt on the frame of the isobaric device.

[0034] Step 2: Formwork.

[0035] According to the geometric dimensions designed in the construction drawings and the designed thickness of the castable (with appropriate consideration of the weight displacement factor), the wooden formwork is laid out, prefabricated and assembled on site on the frame of the isobaric device. The model size must be accurate, the assembly must be firm, the mechanical strength must be high and it must not be easily deformed. There must be no shifting or loosening of the formwork during pouring. The formwork material must be smooth and not easy to absorb water. Brush one or two coats of release agent on the surface of the formwork for demoulding to ensure the construction thickness of the castable and a smooth and clean surface after construction.

[0036] Step three, add plastic and pound into shape.

[0037] Before the plastic ramming construction, the surface of the isobaric device frame should be treated to remove floating dust and debris; during the plastic ramming construction, strictly follow the material instructions to control the ingredient ratio, dosage, stirring time, etc., especially the dosage, and ramming should be carried out continuously along the flue gas flow; after the plastic is basically rammed, pay attention to the flatness of the plastic working surface, the convex part must be cut off with a spatula, and the concave part must be excavated and then filled.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A boiler cooling air chamber, characterized in that: It includes an air chamber main body, an air distribution plate and an isobaric device; the air chamber main body is divided into three sections connected to each other along the length direction, and isobaric devices are respectively provided at both ends of the middle section in the length direction, and air inlets connecting the two side sections are respectively provided at both ends of the air chamber main body in the length direction; the isobaric device is provided with an air inlet rebound structure.

2. The boiler cooling air chamber according to claim 1, characterized in that: The bottom of the air chamber body is symmetrically inclined from both sides in the width direction to the middle, and the middle position is lower than the two sides.

3. The boiler cooling air chamber according to claim 2, characterized in that: The angle between the inclined parts on both sides of the bottom of the air chamber body and the horizontal plane is 10° to 15°.

4. The boiler cooling air chamber according to claim 1, characterized in that: The isobaric device comprises an inclined plate which is inclined from the lower part of the two side sections to the upper part of the middle section.

5. The boiler cooling air chamber according to claim 4, characterized in that: The angle between the inclined plate and the horizontal plane is 20° to 30°.

6. The boiler cooling air chamber according to claim 4, characterized in that: The isobaric device also includes a vertical plate, which is vertically arranged, the upper end of the vertical plate is fixedly connected to the upper end of the inclined plate, the lower end of the vertical plate is fixedly connected to the bottom of the air chamber body, and both sides of the inclined plate in the width direction are respectively fixedly connected to the air chamber body.

7. The boiler cooling air chamber according to claim 6, characterized in that: There is a gap between the upper edge of the inclined plate and the air distribution plate, there is a gap between the lower edge of the inclined plate and the bottom of the air chamber body, and an opening is provided at the middle position of the bottom of the vertical plate.

8. The boiler cooling air chamber according to claim 1, characterized in that: The total length of the isobaric device is less than or equal to one third of the total length of the wind chamber body.

9. The boiler cooling air chamber according to claim 1, characterized in that: A plurality of wind hoods are evenly distributed on the wind distribution plate.

10. A method for manufacturing an isobaric device, used for manufacturing an isobaric device in a boiler cooling air chamber according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1, making an isobaric device frame; Step 2: Formwork; Step three, add plastic and pound into shape.

Images