KR102080565B1 - Nozzle of pulverized coal burner - Google Patents

Abstract

A nozzle of a pulverized coal burner according to the present invention includes: a first member positioned on the upstream side of the flow direction of pulverized coal and air; a second member positioned on the downstream side of the flow direction of the pulverized coal and the air, and coupled to the first member; and a nozzle tip coupled to the second member and injecting the pulverized coal and the air. The second member includes a venturi tube. Accordingly, the distribution of the pulverized coal biased on the upper part can be more uniform to reduce factors of incomplete combustion and reduce generation of NOx. In addition, parts changing the distribution of the pulverized coal can be replaced, thereby realizing appropriate distribution of the pulverized coal by replacing parts if necessary.

Description

Nozzle of Pulverized Coal Burner {NOZZLE OF PULVERIZED COAL BURNER}

The present invention relates to a nozzle of a pulverized coal burner, and more particularly, to a nozzle of a pulverized coal burner capable of improving an upper bias phenomenon of pulverized coal.

In general, a nozzle of a pulverized coal burner is used to supply fuel to a combustion chamber.

A nozzle of a conventional pulverized coal burner will be described with reference to FIGS. 1 to 2C.

1 is a perspective view showing a nozzle of a conventional pulverized coal burner, FIG. 2A is a pulverized coal distribution diagram of FIG. 1, FIG. 2B is a pulverized coal distribution diagram at a nozzle tip of FIG. 1, and FIG. It is a figure which shows a density.

As shown in FIG. 1, the nozzle of a conventional pulverized coal burner is a tube 11, a cylindrical tube 12, a connecting tube 13, and a nozzle that are bent from an upstream side to a downstream side based on a flow direction of pulverized coal and air. The tips 14 and the like are connected in turn.

The nozzle of such a conventional pulverized coal burner has a distribution in which most of the pulverized coal is biased on the top of the nozzle as shown in FIGS. 2A and 2B. And as the pulverized coal of such non-uniform distribution is supplied to a combustion chamber, there existed a problem that a large amount of NOx generate | occur | produces.

An object of the present invention is to provide a nozzle of a pulverized coal burner capable of realizing a uniform pulverized coal distribution in order to solve the above problems.

The present invention provides a nozzle for mixing and injecting pulverized coal and air into the burner to achieve the object as described above, the nozzle comprises: a first member located in the flow direction upstream of the pulverized coal and air; A second member positioned downstream of the pulverized coal and air in a flow direction and engaged with the first member; And a nozzle tip coupled to the second member and to which the pulverized coal and air are injected, wherein the second member includes a venturi tube.

In addition, the distance between the venturi tube and the nozzle tip may be shorter than the distance between the venturi tube and the first member.

In addition, the venturi tube may have a blockage ratio of 0.2 or more and 0.3 or less.

Meanwhile, according to another aspect of the present invention, a nozzle for mixing and injecting pulverized coal and air into a burner, the nozzle comprises: a first member located in a flow direction upstream of the pulverized coal and air; A second member positioned downstream of the pulverized coal and air in a flow direction and engaged with the first member; And a nozzle tip coupled to the second member and to which the pulverized coal and air are injected, wherein the second member may be provided with a vane projecting inwardly.

In addition, the vanes may be provided to be spaced apart from each other in the circumferential direction of the second member.

In addition, the vane may be provided only on the upper side of the second member.

In addition, the vane may protrude to contact a circle having a occlusion rate of 0.3 or more and 0.4 or less.

In addition, the vane may form an angle of 30 degrees or more and 45 degrees or less with the longitudinal direction of the second member.

In addition, the second member may include a venturi tube.

In addition, the vane may be provided in the venturi tube.

In addition, the vanes may be formed in a helical shape.

In addition, the vane may form an angle of 20 degrees or more and 30 degrees or less with the longitudinal direction of the second member.

In addition, the vane may protrude to contact a circle having a blockage rate of 0.4 or more and 0.5 or less.

In addition, the vanes may be provided to be spaced apart from each other in the circumferential direction of the second member.

The vane may also include a point where a straight line extending in the longitudinal direction of the second member meets the vane at the tip of another vane adjacent to the vane, and the vane may further extend downstream from the point.

In addition, the length of the vane extending further from the point may be 0.5 times the length from the tip of the vane to the point.

The nozzle of the pulverized coal burner according to the present invention can more uniformly distribute the pulverized coal distribution on the upper side, thereby reducing the factors of incomplete combustion and reducing the generation of NOx.

In addition, it is possible to replace parts for changing the pulverized coal distribution, so that appropriate pulverized coal distribution can be realized by replacing parts as necessary.

1 is a perspective view showing a nozzle of a conventional pulverized coal burner,
2A is a pulverized coal distribution diagram in FIG. 1,
FIG. 2B is a pulverized coal distribution diagram at the nozzle tip of FIG. 1;
Figure 2c is a diagram showing the density of pulverized coal according to the color in the pulverized coal distribution map,
3 is a front view showing the nozzle of the pulverized coal burner according to the first embodiment of the present invention;
4A to 5B are pulverized coal distribution diagrams at the nozzle and nozzle tip of the pulverized coal burner when the block rate of the venturi is changed in the nozzle of the pulverized coal burner according to the first embodiment of the present invention;
6a is a pulverized coal distribution diagram when the position of the venturi is changed in FIGS. 5a to 5b;
6B is a fine coal distribution diagram at the nozzle tip of FIG. 6A;
7A is a front view illustrating a nozzle of a pulverized coal burner according to a second embodiment of the present invention;
FIG. 7B is a cross-sectional view along the line AA ′ in FIG. 7A;
7c is a view of the length of the vane in FIG. 7a,
8A is a pulverized coal distribution diagram in a nozzle of a pulverized coal burner according to a second embodiment of the present invention;
8B is a fine coal distribution diagram at the nozzle tip of FIG. 8A;
9A is a front view illustrating a nozzle of a pulverized coal burner according to a third embodiment of the present invention;
Figure 9b is a cross-sectional view taken along the line AA 'in Figure 9a,
9C is a front view illustrating the nozzle of the pulverized coal burner having the vane angle changed in FIG. 9A;
10A is a pulverized coal distribution diagram in a nozzle of a pulverized coal burner according to a third embodiment of the present invention;
10B is a pulverized coal distribution diagram at the nozzle tip of FIG. 10A,
FIG. 11A is a pulverized coal distribution diagram in a nozzle of a pulverized coal burner having a vane like FIG. 9C;
FIG. 11B is a fine coal distribution diagram at the nozzle tip of FIG. 11B;
12 is a front view showing the nozzle of the pulverized coal burner according to the fourth embodiment of the present invention;
13A is a pulverized coal distribution diagram in a nozzle of a pulverized coal burner according to a fourth embodiment of the present invention;
13B is a pulverized coal distribution diagram at the nozzle tip of FIG. 13A,
14A is a pulverized coal distribution diagram when the blockage rate of the venturi is changed in the nozzle of the pulverized coal burner according to the fourth embodiment of the present invention;
14B is a pulverized coal distribution diagram at the nozzle tip of FIG. 14A,
15 is a front view showing the nozzle of the pulverized coal burner according to the fifth embodiment of the present invention;
16A is a pulverized coal distribution diagram in a nozzle of a pulverized coal burner according to a fifth embodiment of the present invention;
FIG. 16B is a pulverized coal distribution diagram at the nozzle tip of FIG. 16A; FIG.
17A is a pulverized coal distribution diagram when a vane is in contact with a circle having an occlusion rate of 0.45 in a nozzle of a pulverized coal burner according to a fifth embodiment of the present invention;
17B is a fine coal distribution diagram at the nozzle tip of FIG. 17A;
18A is a pulverized coal distribution diagram when a vane is in contact with a circle having a blockage rate of 0.5 in a nozzle of a pulverized coal burner according to a fifth embodiment of the present invention;
18B is a fine coal distribution diagram at the nozzle tip of FIG. 18A;
19 is a cross-sectional view showing a nozzle of a pulverized coal burner according to a sixth embodiment of the present invention;
20 is a perspective view of the wedge in FIG. 19, FIG.
21A is a pulverized coal distribution diagram in a nozzle of a pulverized coal burner according to a sixth embodiment of the present invention;
FIG. 21B is a fine coal distribution diagram at the nozzle tip of FIG. 21A; FIG.
22A is a pulverized coal distribution diagram when an angle of a wedge is 45 degrees in a nozzle of a pulverized coal burner according to a sixth embodiment of the present invention;
FIG. 22B is a fine coal distribution diagram at the nozzle tip of FIG. 22A; FIG.
23 is a perspective view illustrating a wedge in a nozzle of a pulverized coal burner according to a seventh embodiment of the present invention;
24A is a pulverized coal distribution diagram in a nozzle of a pulverized coal burner according to a seventh embodiment of the present invention;
24B is a fine coal distribution diagram at the nozzle tip of FIG. 24A,
25 is a cross-sectional view showing a nozzle of a pulverized coal burner according to an eighth embodiment of the present invention;
FIG. 26 is a perspective view of the wedge in FIG. 25;
27A is a pulverized coal distribution diagram in a nozzle of a pulverized coal burner according to an eighth embodiment of the present invention;
FIG. 27B is a pulverized coal distribution diagram at the nozzle tip of FIG. 27A; FIG.
FIG. 28 is a front view of FIG. 26.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a front view illustrating a nozzle of the pulverized coal burner according to the first embodiment of the present invention, and FIGS. 4A to 5B are views of changing the blockage rate of the venturi at the nozzle of the pulverized coal burner according to the first embodiment of the present invention. Figure 6a shows the pulverized coal distribution in the nozzle and nozzle tip of the pulverized coal burner. 7A is a front view showing a nozzle of a pulverized coal burner according to a second embodiment of the present invention, FIG. 7B is a sectional view taken along the line AA ′ in FIG. 7A, FIG. 7C is a view of the vane length in FIG. 7A, and FIG. Pulverized coal distribution diagram at the nozzle of the pulverized coal burner according to the second embodiment, FIG. 8B is a pulverized coal distribution diagram at the nozzle tip of FIG. 8A, and FIG. 9A is a front view showing the nozzle of the pulverized coal burner according to the third embodiment of the present invention. 9B is a cross-sectional view along the line AA ′ in FIG. 9A, and FIG. 9C is FIG. 9A 10A is a front view showing a nozzle of a pulverized coal burner in which the angle of the sub vane is changed, FIG. 10A is a fine coal distribution diagram at a nozzle of a pulverized coal burner according to a third embodiment of the present invention, and FIG. 10B is a fine coal distribution diagram at a nozzle tip of FIG. 10A FIG. 11A is a pulverized coal distribution diagram at a nozzle of a pulverized coal burner having a vane as shown in FIG. 9C, FIG. 11B is a pulverized coal distribution diagram at a nozzle tip of FIG. 11B, and FIG. 12 is a nozzle of a pulverized coal burner according to a fourth embodiment of the present invention. 13A is a pulverized coal distribution diagram at the nozzle of the pulverized coal burner according to the fourth embodiment of the present invention, FIG. 13B is a pulverized coal distribution diagram at the nozzle tip of FIG. 13A, and FIG. 14A is a fourth embodiment of the present invention. The pulverized coal distribution diagram when the obturation rate of the venturi is changed in the nozzle of the pulverized coal burner according to the present invention, FIG. 14B is a pulverized coal distribution diagram at the nozzle tip of FIG. 14A, and FIG. 15 is a nozzle of the pulverized coal burner according to the fifth embodiment of the present invention.16A is a pulverized coal distribution diagram at the nozzle of the pulverized coal burner according to the fifth embodiment of the present invention, FIG. 16B is a pulverized coal distribution diagram at the nozzle tip of FIG. 16A, and FIG. 17A is a pulverized coal according to the fifth embodiment of the present invention Pulverized coal distribution diagram when the vanes at the burner nozzle contact a circle with a blockage rate of 0.45, FIG. 17B is a pulverized coal distribution diagram at the nozzle tip of FIG. 17A, and FIG. 18A is a vane at the nozzle of the pulverized coal burner according to the fifth embodiment of the present invention. Fig. 18B is a pulverized coal distribution diagram at the nozzle tip of Fig. 18A, Fig. 19 is a sectional view showing the nozzle of the pulverized coal burner according to the sixth embodiment of the present invention, Fig. 20 19 is a perspective view showing the wedge in FIG. 19, FIG. 21A is a pulverized coal distribution diagram at the nozzle of the pulverized coal burner according to the sixth embodiment of the present invention, FIG. 21B is a pulverized coal distribution diagram at the nozzle tip of FIG. 21A, and FIG. 22A is a According to the sixth embodiment Pulverized coal distribution diagram when the wedge angle of the pulverized coal burner is 45 degrees, FIG. 22B is a pulverized coal distribution diagram at the nozzle tip of FIG. 22A, and FIG. 23 is a wedge at the nozzle of the pulverized coal burner according to the seventh embodiment of the present invention. 24A is a pulverized coal distribution diagram at the nozzle of the pulverized coal burner according to the seventh embodiment of the present invention, FIG. 24B is a pulverized coal distribution diagram at the nozzle tip of FIG. 24A, and FIG. 25 is a pulverized coal burner according to the eighth embodiment of the present invention Fig. 26 is a perspective view of the wedge in Fig. 25, Fig. 27A is a pulverized coal distribution diagram in the nozzle of the pulverized coal burner according to the eighth embodiment of the present invention, Fig. 27B is a view in the nozzle tip of Fig. 27A Pulverized coal distribution diagram, FIG. 28 is a front view of FIG.

In general, coal-fired power plants generate power using heat generated by burning pulverized coal. In the power generation process, first, coal is pulverized in a coal mill to produce pulverized coal, and the pulverized coal is supplied to a damper through a conduit. In the damper, pulverized coal and air are mixed in a certain ratio, and the mixed pulverized coal and air are supplied into the furnace. The combustion of the pulverized coal supplied into the furnace vaporizes the water in the water pipe, and generates electric power by rotating the turbine with the vaporized water, that is, steam. In the coal-fired power plant, the nozzle of the pulverized coal burner corresponds to a conveying apparatus for supplying the mixed pulverized coal and air into the furnace, and in general, a plurality of nozzles may be installed in the furnace.

Hereinafter, a case in which the nozzle of the present invention is used in a furnace of a coal-fired power plant will be described by way of example, but the present invention is not necessarily limited thereto.

[First Embodiment]

Hereinafter, the nozzle of the pulverized coal burner according to the first embodiment of the present invention will be described with reference to FIGS. 3 to 6B.

The nozzle 10 of the pulverized coal burner according to the first embodiment of the present invention includes a first member 100, a second member 200, and a nozzle tip 300.

In the present embodiment, the first member 100 and the second member 200 is formed of a cylindrical tube, but is not limited thereto, and the first member 100 and the second member 200 may move fluid. Any shape can be used as long as the conduit is formed with a tube. The first member 100 is bent and the second member 200 is straight. The second member 200 may be coupled to an end of the first member 100, and the second member 200 may be detachably coupled to the first member 100 as necessary.

The nozzle tip 300 is a portion to which the fluid moved through the first member 100 and the second member 200 is injected. In general, in order to improve durability of the nozzle tip, a nozzle tip having a structure in which a wall is doubled, pulverized coal is supplied to the inner space, and a part of combustion air is supplied to the outside is known. However, in the present invention, in addition to the nozzle tip of such a structure, it is possible to change to a nozzle tip of another structure that can be appropriately selected by a person skilled in the art.

In the present embodiment, a venturi tube 210 (venturi) is formed in the second member 200. The venturi tube 210 has a passage in which the cross section is narrowed so as to lower the pressure of the fluid passing through the tube, and the venturi tube 210 can obtain the venturi effect. In this embodiment, due to the venturi effect, the pressure of the pulverized coal and air passing through the second member 200, precisely the venturi tube 210, is reduced, and consequently, the second member 200 and The distribution of pulverized coal passing through the nozzle tip 300 may be even. That is, the pulverized coal can be uniformly distributed in all regions without biasing the top of the nozzle.

At this time, the blockage ratio indicating a rate at which the cross-sectional area of the tube is reduced due to the venturi tube 210 is preferably 0.2 or more and 0.3 or less. That is, the venturi tube 210 blocks 0.2 or more and 0.3 or less of the internal cross-sectional area of the second member 200.

When the occlusion rate is less than 0.2, the change in the pulverized coal distribution due to the Venturi effect does not appear sufficiently, and thus it is difficult to achieve the object of the present invention to uniform the pulverized coal distribution. On the contrary, when the occlusion rate exceeds 0.3, the pressure difference between the fluid flowing through the first member 100 and the second member 200, that is, the differential pressure becomes excessively large. That is, the pressure of the pulverized coal and air that passed through the venturi tube 210 is greatly lowered, which is inappropriate to apply to an actual product. For the reason as described above, the occlusion rate of the venturi 210 is preferably 0.2 or more and 0.3 or less.

4A and 4B are pulverized coal distribution diagrams of the nozzle and the nozzle tip 300 when the obturation rate of the venturi tube 210 is 0.2, and FIGS. 5A and 5B show the obstruction rate of the venturi tube 210. It is a pulverized coal distribution map in the nozzle and the nozzle tip 300 at this 0.3. Comparing the two, it can be seen that the distribution of pulverized coal has a relatively even distribution when the occlusion rate is 0.3 when the occlusion rate is 0.3.

6A and 6B are pulverized coal distribution diagrams when the venturi tube 210 having an occlusion rate of 0.3 is moved to a downstream side by a predetermined distance in this embodiment. In this case, the venturi tube 210 is located closer to the nozzle tip 300 than the first member 100. Referring to FIG. 6B, it is confirmed that the pulverized coal distribution in the nozzle tip 300 is evenly distributed in the upper and lower portions without biasing the upper portion.

Second Embodiment

Hereinafter, a nozzle of a pulverized coal burner according to a second embodiment of the present invention will be described with reference to FIGS. 7A to 8B.

In this embodiment, the vane 220 is provided on the second member 200. The vane 220 is formed to protrude toward the inside of the second member 200 as shown in FIG. 7A. The vanes 220 may be formed in plural, and may be provided in a state in which the vanes 220 are spaced apart from each other along the circumferential direction of the second member 200.

In the present embodiment, the plurality of vanes 220 are provided only on the upper side of the second member 200. Specifically, as illustrated in FIG. 7B, the plurality of vanes 220 includes one vane spaced apart at equal intervals on both sides about one vane positioned on the upper portion of the second member 200. It can be made of a total of three. In this case, the angle α of the vane 220 in the longitudinal direction of the second member 200 is preferably 30 degrees or more and 45 degrees or less. Problems that occur when the length of the vane 220 is in the length direction of the second member 200 when the angle is less than 30 degrees and exceeds 45 degrees are as described in the first embodiment.

The vanes 220 preferably protrude to contact a virtual circle having a occlusion rate of 0.3 or more and 0.4 or less. This is because when the occlusion rate exceeds 0.4, the differential pressure increases significantly, and below 0.3, the pulverized coal distribution is not effectively improved. Therefore, by selecting an appropriate ratio in the range of 0.3 or more and 0.4 or less, an effective pulverized coal distribution can be realized.

This will be described in detail with reference to FIG. 7B.

7B is a front view illustrating a size in which the vane 220 protrudes inwardly of the second member 200 in the present embodiment. That is, the second member 200 is a cross section of a circle having a diameter of D1, and a circle having a diameter of D2 smaller than D1 has a block rate of 0.3 or more and 0.4 or less. According to the definition of the occlusion rate described above, for example, when the occlusion rate is 0.3, the area of a circle having a diameter D1 is A1, and the area of the circle having a diameter D2 is A2, where A1-A2 = A1 * 0.3.

8A and 8B are pulverized coal distribution diagrams at the nozzle and the nozzle tip when the vanes 220 are formed at a 45 degree angle. 2A and 2B, it can be seen that the vanes 220 are provided to reduce the degree of pulverized coal dust on the top of the nozzle.

7C illustrates the principle for determining the appropriate length of the vane 220. Referring to FIG. 7C, the fluid flows from the left to the right, and the vane 220a on the upper side may theoretically cover all the fluids by the length of L due to the vane 220b on the lower side.

That is, a straight line extending in the longitudinal direction of the second member from the tip of the vane 220b on the lower side meets at one point with the vane 220a on the upper side, from the tip of the vane 220b on the lower side. The distance to the point is L.

In practice, however, a leak of fluid-a fluid flow that does not touch any vanes 220a, 220b-will occur, reducing the effect of improving the pulverized coal distribution. Thus, each vane 220a, 220b has an additional length extending from this point to prevent leakage of fluid. In this embodiment, the additional length is extended as much as 2 / L, but this length is not necessarily 2 / L, and may be determined as appropriate other length as long as it can achieve the purpose of preventing the leakage of fluid. have.

Regarding the length of the vanes 220 described above with reference to FIG. 7C, the same may be applied to other embodiments in which the vanes 220 are formed, and the following description about the length of the vanes 220 will be repeated. Omit.

[Example 3]

Hereinafter, a nozzle of a pulverized coal burner according to a third embodiment of the present invention will be described with reference to FIGS. 9A to 11B.

In the present embodiment, unlike the second embodiment described above, a plurality of vanes 220 'are provided over the entire circumference of the second member 200. The plurality of vanes 220 ′ may be formed of eight vanes as illustrated in FIG. 9B, and may be spaced apart at regular intervals along the circumference of the second member 200. Other parts relating to the angle, length, and protruding size of each vane 220 'are the same as described in the second embodiment.

In FIG. 9A, when the vane 220 ′ forms an angle of 45 degrees with the length direction of the second member 200, in FIG. 9C, the vanes 220 ′ forms the length direction of the second member 200. The cases where the angle is 30 degrees are respectively shown.

10A and 10B are pulverized coal distribution diagrams when the vane 220 'is formed at an angle of 45 degrees with the length direction of the second member 200, and FIGS. 11A and 11B are vanes 220' made of the second powder. It is a pulverized coal distribution map when the angle formed with the longitudinal direction of the two members 200 is 30 degrees. Comparing the above two cases, it can be seen that the pulverized coal distribution changes depending on the angle. In particular, when looking at the distribution of pulverized coal in the nozzle tip 300, FIG. 11B has a significant amount of pulverized coal concentrated at the top compared to FIG. 10B.

However, in this embodiment, changing the angle or number of the vanes 220 'is more uniform than the pulverized coal distribution of the conventional nozzle in which the vanes 220' are not formed, and various other pulverized coal distributions are realized. The purpose is to obtain the appropriate pulverized coal distribution in the situation. Thus, no particular value is in a superior relationship, such as always being more effective than others.

[Example 4]

Hereinafter, a nozzle of a pulverized coal burner according to a fourth embodiment of the present invention will be described with reference to FIGS. 12 to 14B.

In the present embodiment, as described in the first embodiment, the second member 200 includes the venturi tube 210, and as described in the third embodiment, the second member 200 is described. The vane 220 "is provided. That is, the venturi tube 210 and the vane 220" are both provided. In particular, as illustrated in FIG. 12, the vane 220 ″ may be provided in the venturi tube 210.

In this case, since the description of the venturi tube 210 and the vane 220 ″ is the same as described in the first and second embodiments, it will be omitted.

13A and 13B are pulverized coal distribution diagrams when the occlusion rate of the venturi tube 210 is 0.3. 5a and 5b which show the pulverized coal distribution map when only the venturi tube 210 is formed, it can be seen that the pulverized coal is more evenly distributed in the lower part as well as the upper part of the nozzle in this embodiment. That is, the pulverized coal is more evenly distributed when the venturi tube 210 and the vane 220 ″ are formed at the same time, as in the present embodiment, than when the venturi tube 210 is formed as in the first embodiment. Effect occurs.

[Example 5]

Hereinafter, a nozzle of a pulverized coal burner according to a fifth embodiment of the present invention will be described with reference to FIGS. 15 to 18B.

In this embodiment, the spiral vane 230 is provided on the second member 200. The spiral vanes 230 are formed spirally along the circumference of the second member 200, unlike the vanes 220 in the second to fourth embodiments having a straight shape. That is, as shown in FIG. 15, the spiral vanes 230 form a smooth curve.

The spiral vanes 230 may be formed in plural, and preferably, six spiral vanes 230 may be spaced apart at regular intervals along the circumference of the second member 200.

In this embodiment, the angle of the spiral vane 230 and the longitudinal direction of the second member 200 is 25 degrees, it is preferable that the angle is 20 degrees or more and 30 degrees or less. That is, unlike the present embodiment, it may be performed at an angle other than 25 degrees.

The spiral vane 230 is preferably protruded to contact the imaginary circle having a occlusion rate of 0.4 or more and 0.5 or less. This is because the differential pressure increases significantly when the occlusion rate exceeds 0.5, and the pulverized coal distribution does not improve effectively below 0.4. Therefore, by selecting an appropriate ratio in the range of 0.4 or more and 0.5 or less, an effective pulverized coal distribution can be realized.

16A and 16B show the pulverized coal distribution when the helical vane 230 abuts a circle having an occlusion rate of 0.4.

17A and 17B show the pulverized coal distribution when the helical vane 230 abuts a circle having an occlusion rate of 0.45.

18A and 18B show the pulverized coal distribution when the helical vane 230 abuts a circle having an occlusion rate of 0.5.

Referring to FIGS. 16A to 18B, as the spiral vanes 230 are formed, the pulverized coal distribution is evenly distributed on the top and the bottom of the nozzle, and the specific pulverized coal distribution varies according to the size of the spiral vanes 230 protruding. You can see that.

[Example 6]

Hereinafter, a nozzle of a pulverized coal burner according to a sixth embodiment of the present invention will be described with reference to FIGS. 19 to 22B.

In the present embodiment, the wedge 240 is provided on the second member 200. 19 and 20, the wedge 240 is positioned above the second member 200 and protrudes inward of the second member 200.

As shown in FIG. 20, the wedge 240 has a first surface 240c facing the center direction of the second member 200, a second surface 240d facing the downstream side, and an upstream side. It looks at an angle and includes third and fourth surfaces 240a and 240b that meet both the first surface 240c and the second surface 240d. In this case, the third surface 240a and the fourth surface 240b are symmetric with each other.

However, the wedge 240 is not necessarily limited to such a shape, and may be formed in various three-dimensional shapes including a plurality of planes or curved surfaces. However, the wedge 240 should be formed to be symmetrical with respect to the center in the longitudinal direction of the second member 200 to effectively achieve the purpose of improving the pulverized coal distribution.

At this time, the angle θ of the vertex located in the direction of the first member 100 on the surface 240c facing the center direction of the second member 200-hereinafter, it is defined as 'the angle of the wedge'- It is preferable that they are 30 degrees or more and 45 degrees or less. This is because when the angle of the wedge 240 is less than 30 degrees, the change in the pulverized coal distribution is small and ineffective.

The wedge 240 preferably protrudes so as to contact an imaginary circle having an occlusion rate of 0.4 or more and 0.6 or less. This is because the differential pressure increases greatly when the occlusion rate exceeds 0.6, and the pulverized coal distribution does not improve effectively below 0.4. Detailed description thereof will be described later with reference to FIG. 28 in the eighth embodiment.

FIG. 21A is a pulverized coal distribution diagram when the wedge 240 has an angle of 30 degrees and the wedge 240 is in contact with a circle having an occlusion rate of 0.55. FIG. 21B is a pulverized coal distribution diagram at the nozzle tip in FIG. 21A. FIG.

FIG. 22A is a pulverized coal distribution diagram when the wedge 240 has an angle of 45 degrees and the wedge 240 contacts a circle having a blockage rate of 0.5. FIG. 22B is a fine coal distribution diagram at the nozzle tip in FIG. 22A; FIG.

Comparing FIG. 21B and FIG. 22B, in both cases, the pulverized coal is partially biased toward the lower end, and the pulverized coal distribution changes according to the shape and size of the wedge 240. Therefore, the shape and size of the wedge 240 can be appropriately selected according to the situation.

Seventh Example

Hereinafter, a nozzle of a pulverized coal burner according to a seventh embodiment of the present invention will be described with reference to FIGS. 23 through 24B.

In the present embodiment, the wedge 240 is formed with a first inclined surface 242. The first inclined surface 242 blunts the edge of the wedge 240, and is formed at an edge where two surfaces facing the upstream side of the wedge 240 meet as shown in FIG. 23. The first inclined surface 242 is perpendicular to the inner surface of the second member 200. That is, the first inclined surface 242 faces the upstream side.

In this case, the width of the first inclined surface 242 is preferably formed at a ratio of 0.5 or less with respect to the width of the wedge 240. This is because the differential pressure greatly increases when the ratio exceeds 0.5.

The main purpose of the first inclined surface 242 is formed on the wedge 240 is to prevent the edge portion of the wedge 240 is worn. Therefore, the first inclined surface 242 may be implemented in various sizes and shapes as long as it can function as described above.

Referring to FIGS. 24A and 24B, the pulverized coal in the nozzle tip according to the present embodiment can be seen to be evenly distributed in the upper and lower portions as compared with the sixth embodiment.

[Example 8]

Hereinafter, a nozzle of a pulverized coal burner according to an eighth embodiment of the present invention will be described with reference to FIGS. 25 through 27B.

In the present embodiment, the wedge 240 is formed with a first inclined surface 242 ′ and a second inclined surface 244.

The first inclined surface 242 ′ is as described in the seventh embodiment.

The second inclined surface 244 is for blunting the corner where the wedge 240 and the first inclined surface 242 'meet. As shown in FIG. 26, the wedge 240 and the first inclined surface ( 242 'in the middle corner. In this case, the second inclined surface 244 preferably forms an angle of 120 degrees or more and 150 degrees or less with the first inclined surface 242 '.

The main purpose of the second inclined surface 244 is formed on the wedge 240 is to prevent the edge portion of the wedge 240 is worn. Therefore, the second inclined surface 244 may be implemented in various sizes and shapes as long as it can function as described above.

27A and 27B are pulverized coal distribution diagrams at a nozzle and a nozzle tip of a pulverized coal burner when the wedge 240 has an angle of 45 degrees and the first inclined surface 242 ′ and the second inclined surface 244 are formed. Referring to Figure 27b, it can be seen that the pulverized coal is evenly distributed without any bias in any one of the upper and lower parts of the nozzle tip.

FIG. 28 is a front view illustrating a size in which the wedge 240 protrudes inwardly of the second member 200. That is, the second member 200 is a cross section of a circle having a diameter of D1, and a circle having a diameter of D2 smaller than D1 has a block rate of 0.4 or more and 0.6 or less. According to the definition of the occlusion rate described above, for example, when the occlusion rate is 0.4, the area of a circle having a diameter D1 is A1, and the area of the circle having a diameter D2 is A2, where A1-A2 = A1 * 0.4. The description of the large protrusion of the wedge 240 may be applied to all of the sixth to eighth embodiments having the wedge 240.

As described in the seventh and eighth embodiments of the present invention, the first inclined surface 242 and the second inclined surface 244 also serve to improve the pulverized coal distribution, but the main purpose is to reduce the wear of the wedge 240. will be. That is, when the pulverized coal particles repeatedly hit the edge of the wedge 240, the edge of the wedge 240 may be gradually worn out and damaged. Accordingly, this phenomenon may be improved by forming the first inclined surfaces 242 and 242 ′ and the second inclined surface 244 on the wedge 240.

Meanwhile, in the sixth to eighth embodiments, the wedge 240 is formed in the singular in the upper portion of the second member 200, but the wedge 240 is not necessarily the singular but may be formed in the plural. In other words, like the vanes 220 in the above-described second to fifth embodiments, the wedge 240 may be configured in plural and spaced apart along the inner circumference of the second member 200.

According to the embodiments of the present invention described above, the powdered coal is evenly distributed in the nozzle of the pulverized coal burner. In addition, the pulverized coal distribution is changed as the size and shape of the venturi tube 210, the vanes 220, 220 ′, 220 ″, the spiral vanes 230, and the wedge 240 are variously changed. In addition, since the second member 200 is detachable from the first member 100, the pulverized coal distribution suitable for various situations may be realized only by replacing the second member 200.

100: first member
200: second member
210: Venturi Tube
220, 220 ', 220 ": vane
230: spiral vane
240: wedge
242, 242 ': first slope
244: second slope
300: nozzle tip

Claims (16)

delete delete delete In the nozzle to mix and spray pulverized coal and air into the burner,
The nozzle,
A first member located on an upstream side in the flow direction of the pulverized coal and air;
A second member positioned downstream of the pulverized coal and air in a flow direction, and coupled to the first member; And
And a nozzle tip coupled to the second member and to which the pulverized coal and air are injected.
The second member is provided with a vane protruding inwardly,
The second member includes a venturi tube,
The vane nozzle of the pulverized coal burner, characterized in that provided in the venturi tube. The method of claim 4, wherein
The vane nozzle of the pulverized coal burner, characterized in that the plurality of vanes are provided to be spaced apart from each other in the circumferential direction of the second member. The method of claim 5,
The vane nozzle of the pulverized coal burner, characterized in that provided only on the upper side of the second member. The method of claim 4, wherein
The vane nozzle of the pulverized coal burner, characterized in that protruding to contact a circle having a closing rate of 0.3 or more and 0.4 or less. The method of claim 4, wherein
And said vane forms an angle of 30 degrees or more and 45 degrees or less with a longitudinal direction of said second member. delete delete The method of claim 4, wherein
The vane nozzle of the pulverized coal burner, characterized in that formed in a helical. The method of claim 11,
And said vane forms an angle of 20 degrees or more and 30 degrees or less with a longitudinal direction of said second member. The method of claim 11,
The vane nozzle of the pulverized coal burner, characterized in that protruding to contact a circle having a closing rate of 0.4 or more and 0.5 or less. The method of claim 11,
The vane nozzle of the pulverized coal burner, characterized in that the plurality of vanes are provided to be spaced apart from each other in the circumferential direction of the second member. In the nozzle to mix and spray pulverized coal and air into the burner,
The nozzle,
A first member located on an upstream side in the flow direction of the pulverized coal and air;
A second member positioned downstream of the pulverized coal and air in a flow direction, and coupled to the first member; And
And a nozzle tip coupled to the second member and to which the pulverized coal and air are injected.
The second member is provided with a vane protruding inwardly,
The vanes are provided to be spaced apart from each other in the circumferential direction of the second member,
The vane is,
And a straight line extending in the longitudinal direction of the second member at the tip of another vane adjacent to the vane to meet the vane,
And said vane further extends downstream from said point. The method of claim 15,
The length of the vane extending further from the point,
The nozzle of the pulverized coal burner, characterized in that 0.5 times the length from the tip of the vane to the point.

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