KR102133545B1 - Nozzle of pulverized coal burner - Google Patents

Abstract

The nozzle of the pulverized coal burner according to the present invention comprises: a first member positioned upstream of the flow direction of the pulverized coal and air; A second member positioned downstream of the flow direction of the pulverized coal and air, the second member engaging with the first member; And a nozzle tip coupled with the second member, through which the pulverized coal and air are injected, and the second member is provided with a wedge protruding inward. Thereby, the distribution of pulverized coal that is biased on the upper portion can be made more uniform, thereby reducing the factors of incomplete combustion and reducing NOx generation. In addition, it is possible to replace parts that change the distribution of pulverized coal, so that it is possible to realize an appropriate pulverized coal distribution by replacing parts as necessary.

Description

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.

Generally, a nozzle of a pulverized coal burner is used to supply fuel to the 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 the nozzle tip of FIG. 1, and FIG. 2C is a pulverized coal according to color in the pulverized coal distribution diagram. It is a diagram showing density.

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

In the nozzle of the conventional pulverized coal burner, as shown in FIGS. 2A and 2B, a distribution in which most of the pulverized coal is biased at the top of the nozzle appears. In addition, as the pulverized coal having such a non-uniform distribution is supplied to the combustion chamber, a large amount of NOx is generated.

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 problems as described above.

The present invention, in order to achieve the above object, a nozzle for mixing and spraying pulverized coal and air into the burner, the nozzle comprising: a first member positioned upstream of the flow direction of the pulverized coal and air; A second member positioned downstream of the flow direction of the pulverized coal and air, the second member engaging with the first member; And a nozzle tip coupled with the second member, through which the pulverized coal and air are jetted; and the second member is provided with a wedge protruding inward to provide a nozzle of the pulverized coal burner. .

In addition, the wedge may be located above the second member.

In addition, corners may be formed in the wedge facing the first member.

Further, the wedge includes a first surface facing the center of the second member, and an angle formed by a vertex in a direction facing the upstream side from the first surface may be 30 degrees or more and 45 degrees or less.

In addition, a first inclined surface may be formed in the wedge in a direction facing the upstream side.

In addition, the width of the first inclined surface may have a ratio of 0.5 or less with respect to the width of the wedge.

In addition, a second inclined surface may be formed between the first surface and the first inclined surface in the wedge.

Further, the length of the second inclined surface may have a ratio of 0.5 or less with respect to the width of the first inclined surface.

In addition, the wedge may be projected to contact a circle having an occlusion rate of 0.4 or more and 0.6 or less.

In addition, the wedge is a nozzle of the pulverized coal burner, characterized in that provided in a plurality of spaced apart in the circumferential direction of the second member.

In addition, the wedge, a first surface facing the center of the second member; A second side facing the downstream side of the second member; Third and fourth surfaces facing the upstream side of the second member at an angle, and simultaneously contacting the first and second surfaces; It may include.

Also, the third surface and the fourth surface may be symmetrical to each other.

In addition, the first inclined surface may be perpendicular to the inner surface of the second member.

In addition, the second inclined surface may form an angle of 120 degrees or more and 150 degrees or less with the first inclined surface.

The nozzle of the pulverized coal burner according to the present invention can make the distribution of pulverized coal biased on the upper part more uniform, reducing factors of incomplete combustion and reducing NOx generation.

In addition, it is possible to replace parts that change the distribution of pulverized coal, so that it is possible to realize an appropriate pulverized coal distribution by replacing parts as necessary.

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

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

3 is a front view showing the nozzle of the pulverized coal burner according to the first embodiment of the present invention, and FIGS. 4A to 5B are changing the occlusion rate of the venturi in the nozzle of the pulverized coal burner according to the first embodiment of the present invention. The distribution of pulverized coal at the nozzle and nozzle tip of the pulverized coal burner, FIG. 6A is the pulverized coal distribution diagram when the venturi position is changed in FIGS. 5A to 5B, FIG. 6B is the pulverized coal distribution at the nozzle tip of FIG. 6A, FIG. 7A is The front view showing the nozzle of the pulverized coal burner according to the second embodiment of the present invention, FIG. 7B is a cross-sectional view taken along line AA' in FIG. 7A, FIG. 7C is a view of the vane length in FIG. 7A, and FIG. A pulverized coal distribution at the nozzle of the pulverized coal burner according to the second embodiment, FIG. 8B is a pulverized coal distribution at the nozzle tip of FIG. 8A, and FIG. 9A is a front view and a diagram showing the nozzle of the pulverized coal burner according to the third embodiment of the present invention 9B is a cross-sectional view taken along line AA′ in FIG. 9A, and FIG. 9C is a front view showing a nozzle of the pulverized coal burner with the vane angle changed in FIG. 9A, and FIG. 10A is a nozzle of the pulverized coal burner according to the third embodiment of the present invention. The pulverized coal distribution, FIG. 10B is the pulverized coal distribution at the nozzle tip of FIG. 10A, FIG. 11A is the pulverized coal distribution at the nozzle of the pulverized coal burner with the vane as shown in FIG. 9C, FIG. 11B is the pulverized coal distribution at the nozzle tip of FIG. Is a front view showing a nozzle of a pulverized coal burner according to a fourth embodiment of the present invention, FIG. 13A is a pulverized coal distribution diagram of a nozzle of a pulverized coal burner according to a fourth embodiment of the present invention, and FIG. 13B is a nozzle tip of FIG. 13A The pulverized coal distribution diagram of FIG. 14A is the pulverized coal distribution diagram when the occlusion rate of the venturi is changed in the nozzle of the pulverized coal burner according to the fourth embodiment of the present invention, FIG. 14B is the pulverized coal distribution diagram at the nozzle tip of FIG. 14A, FIG. The front view showing the nozzle of the pulverized coal burner according to the fifth embodiment of the present invention, FIG. 16A is a pulverized coal distribution diagram at the nozzle of the pulverized coal burner according to the fifth embodiment of the present invention, and FIG. 16B is pulverized coal at the nozzle tip of FIG. 16A. Distribution diagram, FIG. 17A seen When the vane in the nozzle of the pulverized coal burner according to the fifth embodiment of the invention comes into contact with a circle having a clogging rate of 0.45, the pulverized coal distribution diagram, FIG. 17B is a pulverized coal distribution diagram at the nozzle tip of FIG. 17A, and FIG. 18A is a fifth embodiment of the present invention When the vane in the nozzle of the pulverized coal burner according to the example comes into contact with a circle having an occlusion rate of 0.5, the pulverized coal distribution diagram, FIG. 18B is the pulverized coal distribution diagram at the nozzle tip of FIG. Fig. 20 is a perspective view showing a 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, and Fig. 21B is in the nozzle tip of Fig. 21A. Pulverized coal distribution, FIG. 22A is a pulverized coal distribution when the angle of the wedge is 45 degrees in the nozzle of the pulverized coal burner according to the sixth embodiment of the present invention, FIG. 22B is a pulverized coal distribution at the nozzle tip of FIG. 22A, FIG. 23 is the present invention A perspective view showing a wedge from the nozzle of the pulverized coal burner according to the seventh embodiment, FIG. 24A is a pulverized coal distribution diagram at the nozzle of the pulverized coal burner according to the seventh embodiment of the present invention, and FIG. 24B is a pulverized coal distribution diagram at the nozzle tip of FIG. 24A , Figure 25 is a cross-sectional view showing the nozzle of the pulverized coal burner according to the eighth embodiment of the present invention, Figure 26 is a perspective view showing the wedge in Figure 25, Figure 27a is a nozzle of a pulverized coal burner according to the eighth embodiment of the present invention The pulverized coal distribution in, FIG. 27B is a pulverized coal distribution in the nozzle tip of FIG. 27A, and FIG. 28 is a front view of FIG. 26.

In general, coal-fired power plants generate power by using heat generated by burning pulverized coal. Looking at the power generation process, first, coal is pulverized into fine particles in a coal pulverizer to produce pulverized coal, and pulverized coal is supplied to the damper through a conduit. In the damper, pulverized coal and air are mixed at a constant ratio, and mixed pulverized coal and air are supplied into the furnace. The water in the water pipe is vaporized according to the combustion of the pulverized coal supplied into the furnace, and the turbine is rotated with vaporized water, that is, water vapor, to generate electric power. In the coal-fired power plant, the nozzle of the pulverized coal burner corresponds to a conveying device that supplies mixed pulverized coal and air into the furnace, and in general, a plurality of nozzles may be installed inside the furnace.

Hereinafter, a case where the nozzle of the present invention is used inside a furnace of a coal-fired power plant is described as an example, but it is not necessarily limited to this, and it will be said that it can be implemented in all kinds of burners that supply fuel.

[First Embodiment]

Hereinafter, a nozzle of a pulverized coal burner according to a 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 this 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 can move fluid. Any shape can be used as long as the passage is formed. The first member 100 is bent, and the second member 200 is formed straight. The second member 200 is coupled to the end of the first member 100, and the second member 200 can be detachably coupled from the first member 100 as needed.

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

In this embodiment, the second member 200 is formed with a venturi tube 210 (venturi). The venturi tube 210 has a passage with a narrow cross-section in order to lower the pressure of the fluid passing through the tube, and the venturi effect can be obtained by the venturi tube 210. Accordingly, in this embodiment, the pressure of the pulverized coal and air passing through the second member 200, precisely, the venturi tube 210 is reduced due to the venturi effect, and consequently, the second member 200 The distribution of pulverized coal passing through the nozzle tip 300 may be even. That is, the pulverized coal can be uniformly distributed to all regions without being biased to the top of the nozzle.

At this time, it is preferable that the occlusion rate (blockage ratio) representing the ratio of the cross-sectional area of the pipe due to the Venturi tube 210 is 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 inner 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 sufficiently appear, and it becomes difficult to achieve the object of the present invention to even the pulverized coal distribution. Conversely, when the occlusion rate exceeds 0.3, the pressure difference, that is, the differential pressure between the fluid flowing through the first member 100 and the second member 200 becomes excessively large. That is, the pressure of the pulverized coal and air that has passed through the Venturi tube 210 is greatly lowered, which is inadequate for application to actual products. For the above reasons, the occlusion rate of the venturi 210 is preferably 0.2 or more and 0.3 or less.

4A and 4B are pulverized coal distributions of the nozzle and the nozzle tip 300 when the occlusion rate of the Venturi tube 210 is 0.2, and FIGS. 5A and 5B are occlusion rates of the Venturi tube 210 This is a distribution diagram of pulverized coal in the nozzle and the nozzle tip 300 at 0.3. Comparing the two, it can be seen that when the occlusion rate is 0.3, the distribution of pulverized coal shows a relatively even distribution compared to when the occlusion rate is 0.2.

6A and 6B are pulverized coal distribution diagrams when the venturi tube 210 having an occlusion rate of 0.3 in this embodiment is moved a predetermined distance downstream. At this time, the venturi tube 210 is located closer to the nozzle tip 300 than the first member 100. Referring to FIG. 6B, it can be seen that the pulverized coal distribution in the nozzle tip 300 is not evenly distributed in the upper portion but is evenly distributed in the upper and lower portions.

[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 Figure 7a. The vanes 220 may be formed in plural, and may be provided in a state spaced apart from each other along the circumferential direction of the second member 200.

In this 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 include one vane spaced at equal intervals on both sides with respect to one vane located on the upper portion of the second member 200. It can be made of a total of three. At this time, the angle (α) that the longitudinal direction of the vane 220 forms with the longitudinal direction of the second member 200 is preferably 30 degrees or more and 45 degrees or less. The problem that occurs when the angle of the vane 220 in the longitudinal direction of the second member 200 is less than 30 degrees and exceeds 45 degrees is as described in the first embodiment.

It is preferable that the vane 220 protrudes in contact with a virtual circle having an 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 greatly increases, and if it is less than 0.3, the pulverized coal distribution is not effectively improved. Therefore, an appropriate pulverized coal distribution can be realized by selecting an appropriate ratio according to the situation in the range of 0.3 or more and 0.4 or less.

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 inside the second member 200 in this 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 an occlusion 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, if the area of a circle having a diameter of D1 is A1 and the area of a circle having a diameter of D2 is A2, A1-A2=A1*0.3.

8A and 8B are pulverized coal distribution diagrams at the nozzle and the nozzle tip when the vane 220 is formed at a 45 degree angle. Looking at this in comparison with FIGS. 2A and 2B, it can be seen that as the vane 220 is provided, the degree to which the pulverized coal is biased at the top of the nozzle is reduced.

7C shows the principle for determining the appropriate length of the vane 220. Based on FIG. 7C, the fluid flows from left to right. Due to the vane 220b on the lower side, the vane 220a on the upper side can theoretically cover all fluids even with a length of L.

That is, the 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, at this time, from the tip of the vane 220b on the lower side. The distance to the point is L.

However, in reality, in this case, the leakage of the fluid-a fluid flow that does not reach any vanes 220a and 220b-occurs, thereby reducing the improvement effect of the pulverized coal distribution. Thus, each vane 220a, 220b has an additional length extending from the point to prevent fluid leakage. At this time, in the present embodiment, the additional length is extended as much as 2/L, but this length does not necessarily have to be 2/L, and may be determined to be a different length as long as it can achieve the purpose of preventing the leakage of fluid. have.

Regarding the length of the vane 220 described above with reference to FIG. 7C, the same can be applied to other embodiments in which the vane 220 is formed. Hereinafter, repeated descriptions regarding the length of the vane 220 will be provided. Omitted.

[Third Example]

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

In FIG. 9A, when the angle formed by the vane 220 ′ with the longitudinal direction of the second member 200 is 45 degrees, in FIG. 9C, the vane 220 ′ forms with the longitudinal direction of the second member 200. Each case with an angle of 30 degrees is shown.

10A and 10B are pulverized coal distribution diagrams when the vane 220' is formed at an angle of 45 degrees to the longitudinal direction of the second member 200, and FIGS. 11A and 11B show that the vane 220' is the first 2 is a pulverized coal distribution when the angle formed by the longitudinal direction of the member 200 is 30 degrees. By comparing the above two cases, it can be seen that the distribution of the pulverized coal varies depending on the angle. In particular, looking at the distribution of pulverized coal in the nozzle tip 300, FIG. 11B shows a significant amount of pulverized coal concentrated in the upper portion 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 different pulverized coal distributions are realized. The objective is to obtain an appropriate pulverized coal distribution in the situation. Therefore, it is not that there is an inferiority relationship such that a certain value is always more effective than another value.

[Fourth Example]

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 this embodiment, as described in the first embodiment, the second member 200 includes the venturi tube 210, and at the same time, as described in the third embodiment, the second member 200 The vane 220" is provided. That is, both the Venturi tube 210 and the vane 220" are provided. In particular, as shown in Figure 12, the vane 220" may be provided in the venturi tube 210.

At this time, the description of the Venturi tube 210 and the vane 220" is the same as that described in the first and second embodiments, and thus 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 showing the distribution of pulverized coal when only the Venturi tube 210 is formed, it can be seen that the pulverized coal is more evenly distributed not only at the top but also at the bottom of the nozzle in the present embodiment. That is, when only the Venturi tube 210 is formed as in the first embodiment, 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. Effect.

[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 second member 200 is provided with a spiral vane 230. The spiral vanes 230 are formed in a spiral shape along the circumference of the second member 200, unlike the vanes 220 in the second to fourth embodiments are formed in a straight line. 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 provided to be spaced apart at regular intervals along the circumference of the second member 200.

In this embodiment, the angle formed by the spiral vane 230 with the length direction of the second member 200 is 25 degrees, but the angle is preferably 20 degrees or more and 30 degrees or less. That is, unlike the present embodiment, it is also possible to perform at an angle other than 25 degrees.

It is preferable that the spiral vanes 230 protrude to contact a virtual circle having an occlusion rate of 0.4 or more and 0.5 or less. This is because when the occlusion rate exceeds 0.5, the differential pressure greatly increases, and if it is less than 0.4, the pulverized coal distribution is not effectively improved. Therefore, an appropriate pulverized coal distribution can be realized by selecting an appropriate ratio according to the situation in the range of 0.4 or more and 0.5 or less.

16A and 16B show the distribution of pulverized coal when the spiral vanes 230 contact a circle having an occlusion rate of 0.4.

17A and 17B show the pulverized coal distribution when the spiral vanes 230 contact a circle having an occlusion rate of 0.45.

18A and 18B show the distribution of pulverized coal when the spiral vanes 230 contact a circle having an occlusion rate of 0.5.

16A to 18B, as the spiral vanes 230 are formed, the pulverized coal distribution is evenly distributed at the upper and lower parts of the nozzle, and the specific pulverized coal distribution varies depending on the size of the helical vanes 230 protruding. You can confirm 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 this 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 inside the second member 200.

The wedge 240, as shown in Figure 20, the first surface (240c) facing the center direction of the second member 200, and the second surface (240d) facing the downstream side, the upstream side It includes the third and fourth surfaces 240a and 240b that face at an angle and meet both of the first surface 240c and the second surface 240d. At this time, the third surface 240a and the fourth surface 240b are symmetrical to each other.

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

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, this is defined as the'angle of the wedge'- It is preferable that it is 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, and if it exceeds 45 degrees, there is a problem that the pulverized coal is biased toward the bottom.

It is preferable that the wedge 240 protrudes in contact with a virtual circle having an occlusion rate of 0.4 or more and 0.6 or less. This is because when the occlusion rate exceeds 0.6, the differential pressure greatly increases, and if it is less than 0.4, the pulverized coal distribution is not effectively improved. A detailed description thereof will be described later with reference to FIG. 28 in the eighth embodiment.

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

22A is a distribution diagram of pulverized coal when the angle of the wedge 240 is 45 degrees and the wedge 240 is in contact with a circle having an occlusion rate of 0.5. 22B is a distribution diagram of pulverized coal at the nozzle tip in FIG. 22A.

When comparing FIGS. 21B and 22B, it can be seen that in both cases, the pulverized coal is somewhat biased toward the bottom, 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 depending on the situation.

[Example 7]

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 to 24B.

In this 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.

At this time, 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 when the ratio exceeds 0.5, the differential pressure increases significantly.

The main purpose of forming the first inclined surface 242 on the wedge 240 is to prevent the corner portion of the wedge 240 from being worn. Therefore, the first inclined surface 242 is not limited to the present embodiment and can be implemented in various sizes and shapes as long as it can perform such functions.

Referring to FIGS. 24A and 24B, it can be seen that the pulverized coal in the nozzle tip according to the present embodiment is distributed evenly over the upper and lower parts compared to 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 to 27B.

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

The first inclined surface 242' is the same 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'). At this time, it is preferable that the second inclined surface 244 forms an angle of 120 degrees or more and 150 degrees or less with the first inclined surface 242'.

The main purpose in which the second inclined surface 244 is formed on the wedge 240 is to prevent the corner portion of the wedge 240 from being worn. Therefore, the second inclined surface 244 is not limited to the present exemplary embodiment and can be implemented in various sizes and shapes as long as it can function.

27A and 27B are angles of the wedge 240 and the degree of distribution of the pulverized coal at the nozzle and nozzle tip of the pulverized coal burner when the first inclined surface 242' and the second inclined surface 244 are formed. Referring to FIG. 27B, it can be seen that the pulverized coal is evenly distributed without being biased at any one of the upper and lower portions of the nozzle tip.

28 is a front view illustrating a size in which the wedge 240 protrudes inside the second member 200 in this 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 an occlusion 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, if the area of the circle having the diameter D1 is A1 and the area of the circle having the diameter D2 is A2, 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 provided with the wedge 240.

As described above in the seventh and eighth embodiments, the first inclined surface 242 and the second inclined surface 244 are also intended 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 collide with the edge of the wedge 240, the edge of the wedge 240 may be gradually worn 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.

On the other hand, in the sixth to eighth embodiments, the wedge 240 is composed of a singular number on the upper portion of the second member 200, but it is not necessary to be singular, and the wedge 240 may also be configured in plural. In other words, like the vane 220 in the second to fifth embodiments described above, the wedge 240 may also be configured to be provided to be spaced along the inner circumference of the second member 200.

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

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

Claims (14)

In the nozzle for mixing and pulverized coal and air into the burner,
The nozzle,
A first member positioned upstream of the flow direction of the pulverized coal and air;
A second member positioned downstream of the flow direction of the pulverized coal and air, the second member engaging with the first member; And
Including the second member, the nozzle tip to which the pulverized coal and air is injected; includes,
The second member is provided with a wedge protruding inward,
The wedge includes a first surface facing the center of the second member,
The wedge has an edge formed in a direction facing the first member,
The angle formed by the vertices in the direction facing the upstream side from the first side is a nozzle of a pulverized coal burner, characterized in that it is 30 degrees or more and 45 degrees or less. According to claim 1,
The wedge is a nozzle of the pulverized coal burner, characterized in that located on the upper side of the second member. delete delete According to claim 1,
The wedge, the nozzle of the pulverized coal burner, characterized in that the first inclined surface is formed in a direction facing the upstream side. The method of claim 5,
The width of the first inclined surface, the nozzle of the pulverized coal burner, characterized in that it has a ratio of 0.5 or less with respect to the width of the wedge. The method of claim 5,
The wedge, a nozzle of the pulverized coal burner, characterized in that a second inclined surface is formed between the first surface and the first inclined surface. The method of claim 7,
The length of the second inclined surface, the nozzle of the pulverized coal burner, characterized in that it has a ratio of 0.5 or less with respect to the width of the first inclined surface. According to claim 1,
The wedge nozzle of the pulverized coal burner, characterized in that it protrudes to contact a circle having an occlusion rate of 0.4 or more and 0.6 or less. According to claim 1,
The wedge is a nozzle of the pulverized coal burner, characterized in that a plurality of spaced apart in the circumferential direction of the second member. According to claim 1,
The wedge,
A first side facing the center of the second member;
A second side facing the downstream side of the second member;
Third and fourth surfaces facing the upstream side of the second member at an angle, and simultaneously contacting the first and second surfaces;
The nozzle of the pulverized coal burner comprising a. The method of claim 11,
The third surface and the fourth surface is a nozzle of the pulverized coal burner, characterized in that symmetrical to each other. The method of claim 5,
The first inclined surface is a nozzle of the pulverized coal burner, characterized in that perpendicular to the inner surface of the second member. The method of claim 7,
The second inclined surface is a nozzle of the pulverized coal burner, characterized in that forming an angle of 120 degrees or more and 150 degrees or less with the first inclined surface.

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