CN211514849U

CN211514849U - Flow equalizing device for primary air duct at inlet of coal mill

Info

Publication number: CN211514849U
Application number: CN201921965881.5U
Authority: CN
Inventors: 郭艳玲
Original assignee: Northwest Electric Power Research Institute of China Datang Corp Science and Technology Research Institute Co Ltd
Current assignee: Northwest Electric Power Research Institute of China Datang Corp Science and Technology Research Institute Co Ltd
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-09-18
Anticipated expiration: 2029-11-14

Abstract

The utility model relates to a coal fired power plant coal pulverizer primary air flow equalizing technical field, in particular to a flow straightener that is used for coal pulverizer entry primary air duct, including hot primary air pipe and cold primary air pipe, be equipped with hot primary air pipe valve on the hot primary air pipe, cold primary air pipe is equipped with cold primary air pipe valve, be equipped with cold primary air interface on the cold primary air pipe, cold primary air pipe is connected with hot primary air pipe through cold primary air interface, and cold primary air interface one end is connected with cold primary air pipe, utilizes toper flow equalizing plate to increase the turbulent flow of hot primary air after the valve, is favorable to the heat exchange between cold, the hot primary air; the flow equalizing device can improve the mixing intensity of cold air and hot air, improve the layered flow phenomenon, further improve the flow uniformity of the primary air flow measuring section, and better and uniformly mix the temperature distribution.

Description

Flow equalizing device for primary air duct at inlet of coal mill

Technical Field

The utility model relates to a coal fired power plant's coal pulverizer wind technical field that flow equalizes, in particular to a flow straightener that is used for coal pulverizer entry wind channel.

Background

At present, the phenomenon of compact air duct arrangement generally exists in coal-fired thermal power plants in northwest regions of China, wherein the phenomenon that cold and hot primary air ducts at inlets of coal mills are not uniformly mixed, flow in layers and even flow back easily occurs due to the fact that the cold and hot primary air ducts are often lack of flow guide devices and the straight pipe sections are not long enough after being converged. This phenomenon is more serious with the decrease of the opening of the hot primary air damper and the increase of the opening of the cold primary air damper, which causes the misalignment of the flow measuring device located in the straight pipe section after the mixing of the cold primary air and the hot primary air. The primary wind speed direction of the cross section is unstable, and part of the cross section is not just opposite to the measuring element, so that the requirement of the measuring element on the incoming flow speed direction during normal working can not be met, the primary wind flow at the inlet of the coal mill is inaccurate to measure, and the normal operation of the automatic control of the wind quantity of the coal mill is influenced. Therefore, the improvement of the uniformity of the flow field in the primary air duct of the coal mill inlet is of great significance.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model provides a can solve a cold wind in the circular wind channel of coal pulverizer entry and a flow straightener for wind channel of coal pulverizer entry of the inhomogeneous problem of temperature distribution after hot-blast mixing.

The utility model relates to a flow straightener for coal mill entry primary air duct, including hot primary air duct and cold primary air duct, be equipped with hot primary air duct accent door on the hot primary air duct, cold primary air duct is equipped with cold primary air duct accent door, be equipped with cold primary air interface on the cold primary air duct, cold primary air duct is connected with hot primary air duct through cold primary air interface, and cold primary air interface one end is connected with cold primary air duct, cold primary air interface is provided with flow straightener, be equipped with a plurality of toper flow equalizing plates between flow straightener and the hot primary air duct accent door, wherein, a plurality of toper flow equalizing plates set up along the vertical direction, flow straightener includes first guide plate and second guide plate, first guide plate is a plurality of, a plurality of first guide plates set up 45 with the horizontal plane, wherein set up through the baffle interval between a plurality of first guide plates, one end of the first guide plate, which is far away from the primary hot air pipe, is provided with an outlet grid, the second guide plate is arranged between the first guide plate and the partition plate, and the second guide plate is arranged in a circular arc shape.

Preferably, the outlet grille comprises a plurality of longitudinal grilles and transverse grilles, wherein the longitudinal grilles are perpendicular to the first guide plate, and the transverse grilles and the first guide plate form an included angle of 30 degrees.

Preferably, the number of the plurality of longitudinal grids is 7, and the number of the plurality of transverse grids is 4.

Preferably, the cold primary air interface is a divergent structure.

Preferably, the primary air flow measuring device further comprises a primary air flow measuring section, and the primary air flow measuring section is arranged in the hot primary air pipe.

Preferably, the coal mill access port is connected with one end, far away from the primary air duct adjusting door, of the primary air duct.

Compared with the prior art, the utility model, following technological effect has been gained:

the conical flow equalizing plate is used for increasing the turbulence of hot primary air after passing through the regulating door, so that the heat exchange between cold primary air and hot primary air is facilitated; the flow equalizing device can improve the mixing intensity of cold air and hot air, improve the layered flow phenomenon, further improve the flow uniformity of the primary air flow measuring section, and better and uniformly mix the temperature distribution.

Drawings

Fig. 1 is a schematic diagram of the prior art.

Fig. 2 is a schematic structural diagram of the present invention.

Fig. 3 is an enlarged view of the flow equalizing device of the present invention.

FIG. 4 is a schematic view of another aspect of a current share device.

Reference numerals: the device comprises a 1-hot primary air pipe, a 2-cold primary air pipe, a 3-cold primary air interface, a 4-hot primary air pipe shutter, a 5-cold primary air pipe shutter, a 6-flow equalizing device, a 7-conical flow equalizing plate, an 8-first flow equalizing plate, a 9-second flow equalizing plate, a 10-longitudinal grating, an 11-transverse grating, a 12-coal mill access port and a 13-primary air flow measuring section.

Detailed Description

Examples

The utility model relates to a flow straightener for coal mill entry primary air duct, as shown in figure 1 and figure 2, including hot primary air duct 1 and cold primary air duct 2, be equipped with hot primary air duct damper 4 on the hot primary air duct 1, cold primary air duct 2 is equipped with cold primary air duct damper 5, install cold primary air interface 3 on the cold primary air duct 2 through the bolt, cold primary air interface 3 is the circle becomes square gradually expanding structure, cold primary air duct 2 is connected with hot primary air duct 1 through cold primary air interface 3, cold primary air interface 3 one end is connected with cold primary air duct 2, cold primary air interface 3 department is provided with flow straightener 6, be equipped with a plurality of toper flow straightener 7 between flow straightener 6 and the hot primary air duct damper 4, wherein, a plurality of toper flow straightener 7 set up along the vertical direction, flow straightener 6 includes first guide plate 8 and second guide plate 9, first guide plate 8 is a plurality of, and a plurality of first guide plates 8 are 45 settings with the level, wherein set up through the baffle interval between a plurality of first guide plates 8, and first guide plate 8 is kept away from 1 one end of hot primary air pipe and is provided with the export grid, second guide plate 9 sets up between first guide plate 8 and baffle, and wherein, second guide plate 9 is convex setting.

In this embodiment, the toper flow equalizing plate 7 that sets up is three, three toper flow equalizing plate 7 is perpendicular setting, the interval enables hot-blast more even between the three toper flow equalizing plate 7, reduce the turbulent flow, first guide plate 8 among the flow straightener 6 is three, through baffle (not shown in the figure) interval between the first guide plate 8, the interval through the baffle, when cold wind is through getting into cold primary air interface 3, can only get into among the three first guide plate 8, the flow uniformity of cold wind has been improved, the export grid that first guide plate 8 cooperation set up can improve the homogeneity that flows through primary air flow measurement cross-section 13, satisfy the requirement to the incoming flow velocity direction when primary air flow measurement cross-section 13 normally works.

The outlet grille comprises a plurality of longitudinal grilles 10 and transverse grilles 11, wherein the longitudinal grilles 10 are perpendicular to the first guide plate 8, the transverse grilles 11 form an included angle of 30 degrees with the first guide plate 8, the number of the longitudinal grilles 10 is in a range of 3-6, in the embodiment, the number of the longitudinal grilles 10 is preferably 4, the number of the transverse grilles 11 is in a range of 5-9, and the number of the transverse grilles 11 is preferably 7.

The cold primary air interface 3 is a gradually expanding structure.

The primary air flow measuring device further comprises a primary air flow measuring section 13, and the primary air flow measuring section 13 is arranged in the hot primary air pipe 1.

The coal mill is characterized by further comprising a coal mill access port 12, wherein the coal mill access port 12 is connected with one end, far away from the hot primary air pipe adjusting door 4, of the hot primary air pipe 1.

The utility model discloses during the use, when cold air is through cold air pipe 2 once and is combined through cold air interface 3 and the hot air that is located hot air pipe 1, hot air is through the tapered flow equalizer 7 and the second guide plate 9 that set up, cold air is through first guide plate 8 and export grid, can reduce the turbulent flow, has effectively played the guide effect to cold air and hot air, has further improved the homogeneity when wind flow measurement cross-section 13 through, effectively reduces flow measurement error.

Claims

1. A flow straightener for a primary air duct at an inlet of a coal mill comprises a primary hot air duct (1) and a primary cold air duct (2), wherein a primary hot air duct gate (4) is arranged on the primary hot air duct (1), a primary cold air duct gate (5) is arranged on the primary cold air duct (2), a primary cold air port (3) is arranged on the primary cold air duct (2), the primary cold air duct (2) is connected with the primary hot air duct (1) through the primary cold air port (3), one end of the primary cold air port (3) is connected with the primary cold air duct (2), and the flow straightener is characterized in that,

a flow equalizing device (6) is arranged at the cold primary air interface (3), a plurality of conical flow equalizing plates (7) are arranged between the flow equalizing device (6) and the hot primary air pipe regulating door (4), wherein the conical flow equalizing plates (7) are arranged along the vertical direction, the flow equalizing device (6) comprises a plurality of first flow guiding plates (8) and a plurality of second flow guiding plates (9), the first flow guiding plates (8) are arranged at an angle of 45 degrees to the horizontal plane, the first flow guiding plates (8) are arranged at intervals through partition plates, and an outlet grid is arranged at one end, away from the hot primary air pipe (1), of each first flow guiding plate (8);

the second guide plate (9) is arranged between the first guide plate (8) and the partition plate, wherein the second guide plate (9) is arranged in a circular arc shape.

2. The flow straightener for the coal mill inlet primary air duct according to claim 1, characterized in that the outlet grille comprises a plurality of longitudinal grilles (10) and transverse grilles (11), wherein the longitudinal grilles (10) are arranged perpendicular to the first deflector (8), and the transverse grilles (11) are arranged at an angle of 30 ° to the first deflector (8).

3. Flow straightener for a coal mill inlet primary air duct according to claim 2, characterized in that the number of longitudinal grids (10) is 7 and the number of transverse grids (11) is 4.

4. The flow straightener for the coal mill inlet primary air duct according to claim 3, characterized in that the cold primary air interface (3) is a divergent structure.

5. The flow straightener for the coal mill inlet primary air duct according to claim 4, characterized in that it further comprises a primary air flow measuring section (13), the primary air flow measuring section (13) being arranged in the hot primary air pipe (1).

6. The flow straightener for the coal mill inlet primary air duct according to claim 5, further comprising a coal mill access port (12), wherein the coal mill access port (12) is connected with one end of the primary hot air duct (1) far away from the primary hot air duct damper (4).