Coal mill inlet air duct flow equalizing system and coal mill

Abstract

The utility model provides a coal mill inlet air duct flow equalizing system and a coal mill, the coal mill inlet air duct flow equalizing system comprises two groups of fan blades, and the two groups of fan blades are both arranged in a hot primary air branch pipe and located at the downstream of a cold primary air pipe. The split type fan blade structure is arranged on the downstream portion of the cold primary air, the air volume can be conveniently adjusted, the structural complexity and size are reduced, and the application range is widened.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal mill structure improvement, and in particular relates to a coal mill inlet air duct flow equalization system and a coal mill. Background Art

[0002] The statements in this section merely provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] Coal-fired boilers in large thermal power plants generally use a direct-blowing pulverizing system. The stability and accuracy of the primary air volume measurement of the coal pulverizer are crucial. However, there is a common problem of uneven flow velocity in the air duct, which makes it difficult for the air volume measurement device to accurately measure the velocity and flow in the air duct. Therefore, measures need to be taken to make the flow in the air duct uniform.

[0004] Chinese invention patent CN 115888963A provides a primary air volume adjustment system at the inlet of a coal mill. Although it can achieve the adjustment of the primary air volume at the inlet of a coal mill, its main components are located upstream and downstream of the cold primary air duct, the arrangement is relatively loose, the required installation space is large, and the scope of application is not wide. Summary of the invention

[0005] In order to solve the above problems, the utility model proposes a coal mill inlet air duct flow equalization system and a coal mill. The utility model arranges a split fan blade structure downstream of the cold primary air, which can easily adjust the air volume, reduces the complexity and size of the structure, and increases the scope of application.

[0006] According to some embodiments, the utility model adopts the following technical solutions:

[0007] A coal mill inlet air duct flow equalization system comprises two groups of fan blades. Both groups of fan blades are arranged in hot primary air branch pipes and are located downstream of cold primary air pipes.

[0008] As an optional implementation, each group of fan blades includes a plurality of fan blades, and the fan blades of different groups are vertically arranged.

[0009] As an optional implementation, each group of fan blades includes 2N fan blades, N is an integer, and two adjacent fan blades are arranged in an open relationship.

[0010] As an optional embodiment, each fan blade has an inclination angle with respect to the horizontal direction.

[0011] As an optional embodiment, there is an angle between blades in different groups.

[0012] As an optional embodiment, the fan blades of different groups are arranged vertically.

[0013] As an optional embodiment, the numbers of blades in different groups are the same.

[0014] A coal mill is provided with the coal mill inlet air duct flow equalization system at the coal mill inlet air duct.

[0015] The hot primary air branch pipe is connected to the hot primary air main pipe.

[0016] The cold primary air duct is connected to the hot primary air branch duct, and the layout direction of the cold primary air duct is parallel to the layout direction of the hot primary air main duct.

[0017] Compared with the prior art, the beneficial effects of the utility model are:

[0018] The utility model can realize relatively uniform flow rate by arranging two groups of split-type fan blades, thereby improving the accuracy of measuring the air volume and temperature at the coal mill inlet.

[0019] The two sets of split-type fan blades of the utility model are both located downstream of the cold primary air, and the split-type fan blades have a compact structure and require a small installation space. Moreover, there is no need to adjust the execution structure operation, and the system structure is simple.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0022] Figure 1 It is a schematic diagram of the coal mill inlet air duct in the prior art;

[0023] Figure 2 is a schematic diagram of the coal mill inlet air duct of this embodiment;

[0024] Figure 3 : is a comparison diagram of the outlet velocity distribution of the prior art and the present embodiment;

[0025] Figure 4 It is the distribution of flow velocity in the upstream and downstream air ducts of the split fan blades of this embodiment.

[0026] Among them, 1. hot primary air main pipe, 2. hot primary air branch pipe, 3. cold primary air duct, 4. the first group of split fan blades, 5. the second group of split fan blades. DETAILED DESCRIPTION

[0027] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0028] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0030] In the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0031] Embodiment 1

[0032] A coal mill inlet air duct flow equalization system, such as Figure 2 As shown, it includes two groups of fan blades, both of which are arranged in the hot primary air branch pipe 2 and located downstream of the cold primary air duct 1.

[0033] In this embodiment, the fan blades are divided into two groups, front and rear, which are arranged perpendicular to each other, and each group of fan blades consists of 6 blades. The fan blades are arranged at intervals, and two adjacent fan blades are in the form of "opening", and the angle between the fan blades and the horizontal direction is a certain angle α.

[0034] The hot primary air branch pipe 2 is connected to the hot primary air main pipe 1.

[0035] like Figure 1 As shown in the figure, when no flow equalization device is installed, the mixing of cold and hot primary air will cause serious uneven flow velocity distribution at the outlet, such as Figure 3 As shown in (a).

[0036] According to numerical simulation, after the airflow passes through the split fan blades, the area with excessively high velocity is significantly reduced, and the overall velocity distribution is uniform. Figure 3 (b) and Figure 4 shown.

[0037] When the speed is uniform, the accuracy of measuring flow velocity and flow rate can be effectively improved.

[0038] Embodiment 2

[0039] The difference from the first embodiment is that the number of double-leaf fan blades in this embodiment is different, with 8 in each group.

[0040] Of course, in some other embodiments, the number, spacing and angle of the split fan blades can also be adjusted according to the flow equalization requirements, flow rate, and the diameters of the hot primary air branch pipes, cold primary air ducts and hot primary air main pipes.

[0041] The above description is only the preferred embodiment of the utility model and is not intended to limit the utility model. For those skilled in the art, the utility model may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principle of the utility model without creative labor shall be included in the protection scope of the utility model.

Claims

1. A coal mill inlet air duct flow equalization system, characterized in that: It includes two sets of fan blades, both of which are arranged in the hot primary air branch pipe and located downstream of the cold primary air duct; Each group of fan blades includes 2N fan blades, N is an integer, and two adjacent fan blades are arranged in an open manner.

2. A coal mill inlet air duct flow equalization system as claimed in claim 1, characterized in that: Each group of fan blades includes a plurality of fan blades, and the fan blades of different groups are vertically arranged.

3. A coal mill inlet air duct flow equalization system as claimed in claim 1, characterized in that: Each fan blade has an inclination angle with the horizontal direction.

4. A coal mill inlet air duct flow equalization system as claimed in claim 1 or 2, characterized in that: There is an angle between the blades of different groups.

5. A coal mill inlet air duct flow equalization system as claimed in claim 1 or 2, characterized in that: The fan blades of different groups are arranged vertically.

6. A coal mill inlet air duct flow equalization system as claimed in claim 1 or 2, characterized in that: The number of fan blades in different groups is the same.

7. A coal mill, characterized in that: The coal mill inlet air duct is provided with a coal mill inlet air duct equalizing system according to any one of claims 1 to 6.

8. A coal mill as claimed in claim 7, characterized in that: The hot primary air branch pipe is connected to the hot primary air main pipe.

9. A coal mill as claimed in claim 8, characterized in that: The cold primary air duct is connected to the hot primary air branch duct, and the layout direction of the cold primary air duct is parallel to the layout direction of the hot primary air main duct.

Images