JP6326918B2 - Pulverized coal burner - Google Patents

Description

  The present invention relates to a pulverized coal burner.

  The pulverized coal burner is attached to, for example, a coal fired boiler. In the pulverized coal burner, pulverized coal obtained by pulverizing coal with a coal pulverizer is mixed with combustion air, and this mixed fluid is ejected from a burner nozzle to a furnace to burn the pulverized coal. In such a pulverized coal burner, the combustion state can be kept good by equalizing the particle concentration of the pulverized coal at the outlet of the burner nozzle.

  FIG. 4 of the following Patent Document 1 discloses a pulverized coal burner including a pulverized coal duct and a wind box. In this pulverized coal burner, pulverized coal is injected from the pulverized coal nozzle at the tip of the pulverized coal duct into the boiler through the burner throat, and the pulverized coal is burned while being mixed with the air supplied from the wind box. Yes. The wind box forms a swirling flow around the pulverized coal nozzle, diffuses the pulverized coal while passing through the burner throat, and makes the particle concentration uniform.

JP-A-6-249410

  By the way, in the pulverized coal burner, in order to maintain good combustion performance, it is necessary to eliminate the uneven pulverized coal concentration at the nozzle outlet. Conventionally, a duct through which pulverized coal flows from the tangent line of the nozzle is used, and a protrusion is provided on the inner side of the outer cylinder in order to suppress internal turning. However, in this configuration, the structure is complicated, and it takes time to manufacture, and wear of the protrusion due to collision with pulverized coal has been a problem.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a pulverized coal burner that suppresses wear, simplifies the structure, and is easy to manufacture.

  In order to solve the above-described problems, the present invention provides a burner nozzle that includes a jet outlet that ejects a mixed fluid of pulverized coal and combustion air, and a transport passage for the mixed fluid that reaches the jet outlet, and a side of the burner nozzle And a mixed fluid inflow pipe that flows the mixed fluid into the transport flow path, and is provided downstream of the connection position of the mixed fluid inflow pipe in the transport flow path, and the mixed fluid inflow pipe is connected A pulverized coal burner having a pulverized coal concentration distribution adjusting member that makes the channel area on the opposite side relatively small with respect to the channel area on the opposite side is employed.

  Moreover, in this invention, the structure that the said pulverized coal density | concentration distribution adjustment member is provided in non-contact with the outer edge outline of the flow-path cross section of the said conveyance flow path is employ | adopted.

  Further, in the present invention, the burner nozzle has a cylindrical inner sleeve and an outer sleeve, and the transport channel is formed between the inner sleeve and the outer sleeve, and the pulverized coal concentration The distribution adjusting member is configured to be supported by the inner sleeve.

  Moreover, in this invention, the structure that the said pulverized coal density | concentration distribution adjustment member has the circular or elliptical outer edge outline eccentric with respect to the axial center of the said burner nozzle is employ | adopted.

  Moreover, in this invention, the structure that the said pulverized coal density | concentration distribution adjustment member is formed with the plate body by which the taper was formed in the outer edge part is employ | adopted.

  Moreover, in this invention, the structure that the said pulverized coal density | concentration distribution adjustment member is formed with the spherical body or the ellipsoid is employ | adopted.

  In the present invention, the pulverized coal concentration distribution adjusting member employs a configuration in which the upstream side is formed of a sphere and the downstream side is formed of an ellipsoid in the transport channel.

In the present invention, a mixed fluid inflow pipe is connected to the side portion of the burner nozzle to form a simple circular pipe combination structure. If this structure is adopted, the mixed fluid bends and circulates to the jet outlet, but when this is bent, the pulverized coal contained in the mixed fluid is opposite to the side where the mixed fluid inflow pipe is connected by centrifugal force. Biased. Therefore, in the present invention, a pulverized coal concentration distribution adjusting member is provided, the flow channel area on the side opposite to the side to which the mixed fluid inflow pipe is connected is relatively narrowed, and a part of the pulverized coal going to the opposite side is mixed. Move to the side where the fluid inflow pipe is connected to make the pulverized coal particle concentration uniform.
Therefore, according to the present invention, a pulverized coal burner that suppresses wear, simplifies the structure, and is easy to manufacture can be obtained.

It is a section lineblock diagram of a pulverized coal burner in a 1st embodiment of the present invention. It is an arrow A figure in FIG. Concept for explaining the relationship between the flow of the mixed fluid in the combined structure of the burner nozzle and the mixed fluid inflow pipe when no pulverized coal concentration distribution adjusting member is provided, and the particle concentration of the pulverized coal at the outlet FIG. It is a section lineblock diagram of a pulverized coal burner in a 2nd embodiment of the present invention. It is an arrow B figure in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional configuration diagram of a pulverized coal burner 1 according to a first embodiment of the present invention. FIG. 2 is an arrow A view in FIG.
The pulverized coal burner 1 jets a mixed fluid F of pulverized coal (schematically indicated by black dots in FIG. 1) and combustion air to a furnace (not shown) to burn the pulverized coal. The pulverized coal burner 1 according to the present embodiment includes a burner nozzle 10, a mixed fluid inflow pipe 20, and a pulverized coal concentration distribution adjusting member 30.

  The burner nozzle 10 has an ejection port 11 that ejects the mixed fluid F, and a transport channel 12 for the mixed fluid F that reaches the ejection port 11. The burner nozzle 10 is formed in a cylindrical shape, and an outlet 11 is formed at one end thereof. The conveyance flow path 12 extends linearly to the ejection port 11 along the axis C <b> 1 of the burner nozzle 10. In the present embodiment, the end of the burner nozzle 10 on the jet outlet 11 side is narrowed, and the mixed fluid F can be ejected toward the axis C1.

  The burner nozzle 10 has a cylindrical inner sleeve 13 and an outer sleeve 14 provided concentrically, and has a double cylinder structure. An oil burner 15 is provided inside the inner sleeve 13. The oil burner 15 ejects oil for ignition at the initial stage of combustion of pulverized coal. The oil burner 15 is provided so as to be able to advance and retreat. The oil burner 15 protrudes from the inner sleeve 13 during ignition and ejects oil. During combustion, the oil burner 15 is retracted into the inner sleeve 13 to prevent burning.

  The transport channel 12 is formed between the inner sleeve 13 and the outer sleeve 14. The flow path cross section of the conveyance flow path 12 is formed in a ring shape as shown in FIG. An inner edge contour 12 a of the cross section of the transport channel 12 is formed by the outer peripheral surface of the inner sleeve 13. Further, the outer edge contour 12 b of the cross section of the transport channel 12 is formed by the inner peripheral surface of the outer sleeve 14.

  As shown in FIG. 1, the mixed fluid inflow pipe 20 is connected to the side portion of the burner nozzle 10 (the outer peripheral surface of the outer sleeve 14). The mixed fluid inflow pipe 20 flows the mixed fluid F into the transport channel 12. The mixed fluid inflow pipe 20 allows the mixed fluid F to flow in a direction perpendicular to the outer sleeve 14. On the upstream side of the mixed fluid inflow pipe 20, a pulverized coal supply device and a blower (not shown) are provided, and a mixed fluid F in which pulverized coal and combustion air are mixed in advance is introduced.

  As shown in FIG. 1, the pulverized coal concentration distribution adjusting member 30 is provided downstream of the connection position of the mixed fluid inflow pipe 20 in the transport channel 12. The pulverized coal concentration distribution adjusting member 30 is opposite to the flow path area S1 on the side to which the mixed fluid inflow pipe 20 is connected (the lower side in the drawing in FIG. 1) (upper side in the drawing in FIG. 1). The flow path area S2 is relatively reduced.

  Specifically, as shown in FIG. 2, the conveyance flow path 12 is divided into two by a straight line L1 passing through the axis C1 of the burner nozzle 10 and flows on the side to which the mixed fluid inflow pipe 20 is connected (the lower side in FIG. 2). The path area S1 is defined, and the side opposite to the side to which the mixed fluid inflow pipe 20 is connected (the upper side in FIG. 2) can be defined as the channel area S2. As shown in FIG. 2, the pulverized coal concentration distribution adjusting member 30 narrows the transport channel 12 on the side opposite to the side to which the mixed fluid inflow pipe 20 is connected, and forms a relationship of channel area S1> channel area S2. It is supposed to be.

  The pulverized coal concentration distribution adjusting member 30 is provided in a non-contact manner with the outer edge contour 12 b of the cross section of the transport flow path 12. The pulverized coal concentration distribution adjusting member 30 is supported on the outer peripheral surface side of the inner sleeve 13. In this embodiment, since the burner nozzle 10 has a double cylinder structure of the inner sleeve 13 and the outer sleeve 14, the pulverized coal concentration distribution adjusting member 30 is supported by supporting the pulverized coal concentration distribution adjusting member 30 on the inner sleeve 13. It can be provided in a non-contact manner with the outer edge contour 12 b of the cross section of the transport channel 12.

  As shown in FIG. 2, the pulverized coal concentration distribution adjusting member 30 has an elliptical outer edge contour 30 a that is eccentric with respect to the axis C <b> 1 of the burner nozzle 10. In the present embodiment, the center C2 of the outer edge contour 30a is eccentric to the side opposite to the side to which the mixed fluid inflow pipe 20 is connected (upper side in FIG. 2) with respect to the axis C1. The elliptical short axis forming the outer edge contour 30a is arranged in parallel with the straight line L1 that bisects the transport flow path 12, and the elliptical long axis is arranged so as to be orthogonal to the straight line L1. Yes.

  As shown in FIG. 1, the pulverized coal concentration distribution adjusting member 30 is formed of a plate body having a taper 31 formed on the outer edge portion. The taper 31 is provided on the upstream side plate surface side and the downstream side plate body rear surface side in the transport flow path 12, respectively. By forming the taper 31, the pulverized coal concentration distribution adjusting member 30 has a large thickness at the center and a small outer edge. The plate surface of the pulverized coal concentration distribution adjusting member 30 is parallel to the flow of the mixed fluid F flowing in from the mixed fluid inflow pipe 20 and is perpendicular to the flow of the mixed fluid F in the transport channel 12. Has been placed.

Then, the effect | action of the pulverized coal burner 1 of the said structure is demonstrated with additional reference to FIG.
3 shows the flow of the mixed fluid F in the combined structure of the burner nozzle 10 and the mixed fluid inflow pipe 20 when the pulverized coal concentration distribution adjusting member 30 is not provided, and the particle concentration of the pulverized coal at the outlet 11. It is a conceptual diagram for demonstrating the relationship.

  The pulverized coal burner 1 of the present embodiment has a simple circular pipe combination structure by connecting the mixed fluid inflow pipe 20 to the side of the cylindrical burner nozzle 10 without adopting a conventional wind box. When this structure is adopted, as shown in FIG. 3, a substantially L-shaped flow path is formed, and the mixed fluid F flowing through the flow path flows through the bent portion 16 before reaching the ejection port 11. . The mixed fluid F contains pulverized coal having a specific gravity higher than that of the combustion air. For this reason, when mixed fluid F distribute | circulates the bending part 16, the pulverized coal in the side opposite to the side to which the mixed fluid inflow pipe 20 is connected by centrifugal force (side corresponding to the outer side of the bending part 16). (Refer to the jet particle concentration shown in FIG. 3).

  Therefore, in the present embodiment, as shown in FIG. 1, the pulverized coal concentration distribution adjusting member 30 is provided in the transport channel 12 on the downstream side of the connection position of the mixed fluid inflow pipe 20. The pulverized coal concentration distribution adjusting member 30 makes the flow area S2 on the opposite side relatively smaller than the flow area S1 on the side to which the mixed fluid inflow pipe 20 is connected. Thus, when the flow path area S2 is relatively reduced due to the presence of the pulverized coal concentration distribution adjusting member 30, the flow path resistance on the side opposite to the side to which the mixed fluid inflow pipe 20 is connected increases. In FIG. A flow as shown by the arrow is formed.

  By this flow, a part of the pulverized coal heading to the side opposite to the side to which the mixed fluid inflow pipe 20 is connected can be moved to the side to which the mixed fluid inflow pipe 20 is connected. Therefore, compared with the case where the pulverized coal concentration distribution adjusting member 30 shown in FIG. 3 is not provided, the particle concentration of the pulverized coal on the side to which the mixed fluid inflow pipe 20 is connected can be increased, The particle concentration of the pulverized coal at the outlet 11 can be made uniform. Therefore, according to the pulverized coal burner 1 of the present embodiment, it is possible to maintain a good combustion state without employing a simple circular tube combination structure and employing a conventional wind box.

  Moreover, the pulverized coal concentration distribution adjusting member 30 of the present embodiment has an elliptical outer edge contour 30a that is eccentric with respect to the axis C1 of the burner nozzle 10, as shown in FIG. According to this configuration, by displacing the pulverized coal concentration distribution adjusting member 30 with respect to the axis C1 of the burner nozzle 10, the flow path area S2 on the side opposite to the side to which the mixed fluid inflow pipe 20 is connected can be easily obtained. Further, as shown by a dotted arrow in FIG. 2, it is easy to move to the side where a part of the mixed fluid inflow pipe 20 of the pulverized coal toward the opposite side is connected.

  Further, the pulverized coal concentration distribution adjusting member 30 of the present embodiment is provided in a non-contact manner with the outer edge contour 12 b of the cross section of the transport flow path 12. As shown in FIG. 3, the pulverized coal contained in the mixed fluid F flows along the inner peripheral surface (wall surface) of the outer sleeve 14 that forms the outer side of the conveying flow path 12 due to the centrifugal force received when bending. For this reason, by providing the pulverized coal concentration distribution adjusting member 30 in a non-contact manner with the outer edge contour 12b of the cross section of the transport channel 12, the collision frequency with the pulverized coal is reduced, and the pulverized coal concentration distribution adjusting member 30 Wear can be suppressed.

  Furthermore, as shown in FIG. 1, the pulverized coal concentration distribution adjusting member 30 of the present embodiment is formed of a plate body having a taper 31 formed on the outer edge portion. If the corner of the outer edge of the plate body that has a high collision frequency with the pulverized coal is not dropped, the corner is actively scraped by the collision with the pulverized coal, and the pulverized coal concentration distribution adjusting member 30 is unevenly worn, and the flow path The ratio between the area S1 and the flow path area S2 may change over time. Therefore, by forming the taper 31 at the outer edge portion, the function of adjusting the particle concentration of the pulverized coal can be kept constant for a long time.

  Thus, according to the above-described embodiment, the burner nozzle 10 including the ejection channel 11 that ejects the mixed fluid F of pulverized coal and combustion air and the transport channel 12 of the mixed fluid F that reaches the ejection port 11; A mixed fluid inflow pipe 20 that is connected to a side portion of the burner nozzle 10 and flows the mixed fluid F into the transport flow path 12, and is provided on the downstream side of the connection position of the mixed fluid inflow pipe 20 in the transport flow path 12. By adopting the configuration of having the pulverized coal concentration distribution adjusting member 30 that relatively reduces the flow area S2 on the opposite side to the flow area S1 on the side to which the inflow pipe 20 is connected, A pulverized coal burner 1 that suppresses wear and simplifies the structure and is easy to manufacture is obtained.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

FIG. 4 is a cross-sectional configuration diagram of the pulverized coal burner 1 according to the second embodiment of the present invention. 5 is an arrow B view in FIG.
As shown in FIG. 4, the second embodiment differs from the above embodiment in that the pulverized coal concentration distribution adjusting member 30 has a thick three-dimensional shape.

  In the pulverized coal concentration distribution adjusting member 30 of the second embodiment, the upstream side of the transport flow path 12 is formed from a sphere, and the downstream side is formed from an ellipsoid. Specifically, as shown in FIG. 4, with the straight line L2 passing through the three-dimensional maximum outer diameter as a boundary, the upstream side of the transport channel 12 is a sphere (indicated by reference numeral 32), and the downstream side of the transport channel 12 is an ellipsoid (reference number). 33). In other words, the pulverized coal concentration distribution adjusting member 30 has a shape in which a halved sphere and a halved ellipsoid are joined by a cut surface.

  Moreover, the pulverized coal concentration distribution adjusting member 30 of the second embodiment has a circular outer edge contour 30b that is eccentric with respect to the axis C1 of the burner nozzle 10, as shown in FIG. In the present embodiment, the center C3 of the outer edge contour 30b is eccentric to the side opposite to the side to which the mixed fluid inflow pipe 20 is connected (upper side in FIG. 5) with respect to the axis C1. Thereby, like the said embodiment, the flow path area S2 of the opposite side can be made relatively small with respect to the flow path area S1 of the side to which the mixed fluid inflow tube 20 is connected.

  According to 2nd Embodiment of the said structure, since the pulverized coal density | concentration distribution adjustment member 30 has a round three-dimensional shape, there is no corner | angular which can be shaved positively by collision with pulverized coal, and the pulverized coal density | concentration distribution adjustment member 30 The uneven wear can be suppressed. Therefore, the adjustment function of the pulverized coal particle concentration of the pulverized coal concentration distribution adjusting member 30 can be kept constant for a longer period.

Further, the front half of the pulverized coal concentration distribution adjusting member 30 is formed of a sphere. The sphere has a physically stable shape, and can improve collision resistance with pulverized coal. For this reason, the abrasion which generate | occur | produces in the upstream of the pulverized coal density | concentration distribution adjustment member 30 can be reduced more. Further, the rear half of the pulverized coal concentration distribution adjusting member 30 is formed of an ellipsoid. The ellipsoid extends smoothly and long downstream, and can suppress the generation of vortices and stagnation on the downstream side of the pulverized coal concentration distribution adjusting member 30. For this reason, the flow of the mixed fluid F on the downstream side of the pulverized coal concentration distribution adjusting member 30 can be stabilized.
Thus, according to 2nd Embodiment mentioned above, in addition to the effect similar to the said embodiment, the abrasion resistance of pulverized coal density | concentration distribution adjustment member 30 is raised more, and also pulverized coal density | concentration distribution adjustment member 30 of The flow of the mixed fluid F after passing can be further stabilized.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, the pulverized coal concentration distribution adjusting member has been described with respect to a configuration formed from a solid body in which a plate body or a sphere and an ellipsoid are combined, but the present invention is not limited to this configuration, for example, The pulverized coal concentration distribution adjusting member may be simply formed of a sphere or an ellipsoid.

  Further, for example, in the above-described embodiment, the configuration in which the pulverized coal concentration distribution adjusting member has a circular or elliptical outer edge contour that is eccentric with respect to the axis of the burner nozzle has been described, but the present invention is limited to this configuration. Instead, for example, if the flow area on the opposite side to the flow area on the side to which the mixed fluid inflow pipe is connected can be made relatively small, a configuration having an irregular outer edge contour may be used. . It is preferable to employ an irregular outer edge contour having no corners.

  Further, for example, in the above embodiment, the configuration in which the pulverized coal concentration distribution adjusting member is supported by the inner sleeve has been described. However, the present invention is not limited to this configuration, and for example, the burner nozzle adopts a double cylinder structure. If not, a configuration may be adopted in which the pulverized coal concentration distribution adjusting member is supported on the tip of a bar extending along the axis of the burner nozzle.

  For example, in the above-described embodiment, the configuration in which the mixed fluid inflow pipe flows the mixed fluid in a direction perpendicular to the outer sleeve has been described. However, the present invention is not limited to this configuration. In order to form a swirling flow, a configuration in which the mixed fluid inflow pipe flows the mixed fluid in a tangential direction of the inner peripheral surface of the outer sleeve may be adopted.

DESCRIPTION OF SYMBOLS 1 ... Pulverized coal burner, 10 ... Burner nozzle, 11 ... Jet outlet, 12 ... Conveyance flow path, 12b ... Outer edge outline, 13 ... Inner sleeve, 14 ... Outer sleeve, 20 ... Mixed fluid inflow pipe, 30 ... Pulverized coal density distribution adjustment Member, 30a ... outer edge contour, 31 ... taper, C1 ... axis, F ... mixed fluid, S1 ... channel area, S2 ... channel area

Claims (8)

A burner nozzle comprising a jet outlet for jetting a mixed fluid of pulverized coal and combustion air, and a transport passage for the mixed fluid leading to the jet outlet;
A mixed fluid inflow pipe connected to a side portion of the burner nozzle and for flowing the mixed fluid into the transport channel;
Provided on the downstream side of the transport flow path from the connection position of the mixed fluid inflow pipe, the flow area on the opposite side is relatively smaller than the flow area on the side to which the mixed fluid inflow pipe is connected. a pulverized coal concentration distribution control member for the possess,
The pulverized coal burner is characterized in that the pulverized coal concentration distribution adjusting member has a circular or elliptical outer edge contour eccentric with respect to the axis of the burner nozzle .   2. The pulverized coal burner according to claim 1, wherein the pulverized coal concentration distribution adjusting member is provided in a non-contact manner with an outer edge contour of a cross section of the transport channel. The burner nozzle has a cylindrical inner sleeve and an outer sleeve,
The transfer flow path is formed between the inner sleeve and the outer sleeve,
The pulverized coal burner according to claim 2, wherein the pulverized coal concentration distribution adjusting member is supported by the inner sleeve. The pulverized coal burner according to any one of claims 1 to 3 , wherein the pulverized coal concentration distribution adjusting member is formed of a plate having a taper formed at an outer edge portion. The pulverized coal burner according to any one of claims 1 to 3 , wherein the pulverized coal concentration distribution adjusting member is formed of a sphere or an ellipsoid. 4. The fine powder according to claim 1 , wherein the pulverized coal concentration distribution adjusting member is formed of a sphere on the upstream side and formed of an ellipsoid on the downstream side in the transfer flow path. Charcoal burner. A burner nozzle comprising a jet outlet for jetting a mixed fluid of pulverized coal and combustion air, and a transport passage for the mixed fluid leading to the jet outlet;
A mixed fluid inflow pipe connected to a side portion of the burner nozzle and for flowing the mixed fluid into the transport channel;
Provided on the downstream side of the transport flow path from the connection position of the mixed fluid inflow pipe, the flow area on the opposite side is relatively smaller than the flow area on the side to which the mixed fluid inflow pipe is connected. A pulverized coal concentration distribution adjusting member,
The pulverized coal burner, wherein the pulverized coal concentration distribution adjusting member is formed of a sphere or an ellipsoid. A burner nozzle comprising a jet outlet for jetting a mixed fluid of pulverized coal and combustion air, and a transport passage for the mixed fluid leading to the jet outlet;
A mixed fluid inflow pipe connected to a side portion of the burner nozzle and for flowing the mixed fluid into the transport channel;
Provided on the downstream side of the transport flow path from the connection position of the mixed fluid inflow pipe, the flow area on the opposite side is relatively smaller than the flow area on the side to which the mixed fluid inflow pipe is connected. A pulverized coal concentration distribution adjusting member,
The pulverized coal burner is characterized in that the pulverized coal concentration distribution adjusting member is formed of a sphere on the upstream side and formed of an ellipsoid on the downstream side in the transport channel.

Images