High Durability Burner Nozzle Tip With Reduced Cracking, Deformation, Wear, And Sagging Phenomena

Abstract

The present invention relates to a highly durable burner nozzle tip with reduced cracking, deformation, wear, and sagging. More specifically, the invention relates to a highly durable burner nozzle tip with reduced cracking, deformation, wear, and sagging that simultaneously achieves the effects of preventing cracking and deformation through thermal stress dispersion and suppressing clinker adhesion through air injection by bending the corner portions of the tubular body without welding and forming cooling holes on the front surface, and blocks wear and slagging caused by pulverized coal through a surface cladding coating layer and a wear-resistant member, while structurally and completely protecting against load sagging to ensure excellent durability even in harsh combustion environments.

Description

Technology Field

[0001] The present invention relates to a highly durable burner nozzle tip with reduced cracking, deformation, wear, and sagging. More specifically, the invention relates to a highly durable burner nozzle tip with reduced cracking, deformation, wear, and sagging that simultaneously achieves the effects of preventing cracking and deformation through thermal stress dispersion and suppressing clinker adhesion through air injection by bending the corner portions of the tubular body without welding and forming cooling holes on the front surface, and blocks wear and slagging caused by pulverized coal through a surface cladding coating layer and a wear-resistant member, while structurally and completely protecting against load sagging to ensure excellent durability even in harsh combustion environments. Background Technology

[0003] In thermal power plants, finely powdered coal from a pulverizer is supplied through a conduit, and the supplied coal is mixed with combustion air at a certain ratio in a damper before being introduced into the furnace of a boiler for combustion. The burner nozzle tip corresponds to the outermost part of the conveying device that supplies this coal and air into the furnace, and it is a critical piece of equipment directly exposed to flames and high-temperature radiant heat exceeding 1,000 degrees inside the furnace. Therefore, to ensure durability, the wall is generally constructed with a double layer, with coal supplied to the inner side and a portion of the combustion air supplied through the outer passage. Additionally, one or more dividing plates are installed inside the inner pipe body to evenly control the flow of the coal and air mixture.

[0004] Recently, as the use of low-quality coal has increased due to reasons such as reducing power generation costs, the operating environment of burner nozzle tips is becoming increasingly harsh. In particular, clinker and slagging phenomena frequently occur during operation, where various impurities contained in the coal melt at high temperatures and adhere to the inner walls of the inner tube or the surfaces of the dividing plates. The accumulation of these solids narrows the outlet area of ​​the nozzle tip, consequently reducing the normal injection volume of pulverized coal and the air required to feed them, thereby causing a significant drop in combustion efficiency.

[0005] Furthermore, when the boiler is in operation, the front of the burner nozzle tip experiences a rapid temperature increase due to the flame, while the interior remains relatively cooler, resulting in an extreme temperature difference compared to the outside of the combustion chamber. This temperature difference causes variations in thermal expansion deformation across different parts of the pipe body, which acts as concentrated stress on the most vulnerable welds, such as the corners of the nozzle tip, leading to fatal cracks. Moreover, this is accompanied by mechanical damage problems, such as severe wear on the leading edge of the split plate caused by high-speed pulverized coal particles and the downward sagging of the split plate due to accumulated slag load (see Fig. 1).

[0006] Burner nozzle tips are equipment installed by precisely adjusting at least four locations inside the furnace at a thermal power plant site. Therefore, if the shape of the nozzle tips becomes distorted or the function is lost due to problems such as cracks, deformation, wear, and sagging as described above, frequent shutdowns for parts replacement and repairs occur, which is a serious problem that significantly impedes the overall efficiency of the thermal power plant. Prior art literature

[0008] U.S. Registered Patent Publication US 5,347,937 (September 20, 1994). U.S. Published Patent Publication US 2023-0038688 (February 9, 2023). U.S. Registered Patent Publication US 2011-0297762 (December 8, 2011). U.S. Registered Patent Publication US 2007-0234938 (Oct. 11, 2007). U.S. Registered Patent Publication US 2009-0277364 (Nov. 12, 2009). The problem to be solved

[0009] The present invention aims to provide a highly durable burner nozzle tip with reduced cracking, deformation, wear, and sagging, which simultaneously achieves the effects of preventing cracking and deformation through thermal stress dispersion and suppressing clinker adhesion through air injection by bending the corner portions of the tubular body without welding and forming cooling holes on the front surface, and blocks wear and slagging caused by pulverized coal through a surface cladding coating layer and a wear-resistant member, and structurally provides perfect protection against load sagging, thereby ensuring excellent durability even in harsh combustion environments. means of solving the problem

[0011] To solve the above-mentioned problem, one embodiment of the present invention is a high-durability burner nozzle tip applied to a boiler of a thermal power plant, comprising: an inner tube body forming an inner passage through which pulverized coal moves and including a plurality of first cooling holes formed by penetrating a plurality of points; an outer tube body spaced apart from the outer side of the inner tube body forming an outer passage through which air moves and including a plurality of second cooling holes formed by penetrating a plurality of points; and a dividing plate disposed on the inner side of the inner tube body to partition the inner passage. The present invention provides a high-durability burner nozzle tip comprising: a wear-resistant member disposed on the inner side of the inner tube body and coupled to the end side of the split plate facing the direction in which pulverized coal is introduced; wherein, during boiler operation, pulverized coal is introduced into the inner passage and discharged forward while air is introduced into the outer passage and discharged forward, and simultaneously, a portion of the air introduced into the outer passage is supplied to the inner side of the inner tube body through the plurality of first cooling holes.

[0012] In some embodiments of the present invention, the inner tube comprises: a first inner body having a rectangular cross-section; a second inner body that is bent and extended inwardly from one end of the first inner body and becomes narrower toward the front; and an inner discharge wing that is bent and extended outwardly from one end of the second inner body and becomes wider toward the front; and the plurality of first cooling holes may be formed by penetrating the inner discharge wing.

[0013] In some embodiments of the present invention, the outer tube comprises: a first outer body having a rectangular cross-section; a second outer body that is bent and extended inwardly from one end of the first outer body and becomes narrower toward the front; and an outer discharge wing that is bent and extended outwardly from one end of the second outer body and becomes wider toward the front; and the plurality of second cooling holes may be formed by penetrating the second outer body and the outer discharge wing.

[0014] In some embodiments of the present invention, the inner tube body may include an inner bend formed at each corner area of ​​the front end of the inner passage, and the outer tube body may include an outer bend formed at each corner area of ​​the front end of the outer passage.

[0015] In some embodiments of the present invention, the inner tube may include: a first inner body having a rectangular cross-section; a second inner body that is bent and extended inwardly from one end of the first inner body and becomes narrower toward the front; and an inner discharge wing that is bent and extended outwardly from one end of the second inner body, becomes wider toward the front, and has an inner bent portion formed in each corner area.

[0016] In some embodiments of the present invention, the outer tube may include: a first outer body having a rectangular cross-section; a second outer body that is bent and extended inwardly from one end of the first outer body and becomes narrower toward the front; and an outer discharge wing that is bent and extended outwardly from one end of the second outer body, becomes wider toward the front, and has an outer bent portion formed at each corner area.

[0017] In some embodiments of the present invention, the high-durability burner nozzle tip may further include a bracket member that connects the inner tube and the outer tube, with one end fixed to the outer surface of the inner tube and the other end fixed to the inner surface of the outer tube.

[0018] In some embodiments of the present invention, each of the one-sided fixing point where the bracket member is fixed to the outer surface of the inner tube and the plurality of first cooling holes may be formed at a spaced position so as not to physically overlap each other, and each of the other-sided fixing point where the bracket member is fixed to the inner surface of the outer tube and the plurality of second cooling holes may be formed at a spaced position so as not to physically overlap each other.

[0019] In some embodiments of the present invention, the high-durability burner nozzle tip may further include a lower reinforcing member installed between the bottom surface of the inner tube and the lower surface of the dividing plate to support the lower part of the dividing plate.

[0020] In some embodiments of the present invention, the lower reinforcing member is made of a plate and, while positioned in a direction perpendicular to the bottom surface of the inner tube, the upper end surface is fixed to the lower surface of the dividing plate and the lower end surface is fixed to the bottom surface of the inner tube.

[0021] In some embodiments of the present invention, each of the plurality of first cooling holes may have a diameter of 5 to 15 mm.

[0022] In some embodiments of the present invention, each of the plurality of second cooling holes may have a diameter of 5 to 15 mm.

[0023] In some embodiments of the present invention, the high-durability burner nozzle tip may have a clad coating layer formed by heat treating the inner surface of the inner tube body after spraying a self-fluxing alloy.

[0024] In some embodiments of the present invention, the high-durability burner nozzle tip may have a clad coating layer formed by heat treatment after spraying a self-fluxing alloy onto the surface of the dividing plate.

[0025] In some embodiments of the present invention, the high-durability burner nozzle tip may have a clad coating layer formed by heat treatment after spraying a self-fluxing alloy onto the surface of the dividing plate and the surface of the lower reinforcing member.

[0026] In some embodiments of the present invention, the self-fluxing alloy may include Ni.

[0027] In some embodiments of the present invention, the wear-resistant member may be either a ceramic material or a cemented carbide.

[0028] In some embodiments of the present invention, the wear-resistant member may include: an upper fixing portion located on the upper side of the dividing plate; a collision portion extending downward from one end of the upper fixing portion and having an outer surface formed convexly toward the rear of the inner passage; and a lower fixing portion extending forward from one end of the collision portion and located on the lower side of the dividing plate.

[0029] In some embodiments of the present invention, the wear-resistant member forms a U-shaped cross-section by means of the upper fixing part, the impact part, and the lower fixing part, and the end side facing the direction in which pulverized coal flows among the ends of the dividing plate can be accommodated in the inner space of the U-shaped cross-section.

[0030] In some embodiments of the present invention, the wear-resistant member may have a bond applied to the inner space of the U-shaped cross section, and while the bond is applied to the inner space of the U-shaped cross section, the end side of the end of the dividing plate facing the direction in which pulverized coal flows in may be received in the inner space of the U-shaped cross section and fixed to each other. Effects of the invention

[0032] According to one embodiment of the present invention, by organically combining a cooling hole, a bending portion, a lower reinforcing member, and a wear-resistant member within a single nozzle tip structure, it is possible to simultaneously protect against severe thermal damage such as cracks and thermal deformation and mechanical damage such as wear and sagging within the boiler furnace, thereby dramatically extending the product's lifespan.

[0033] According to one embodiment of the present invention, the number of times a boiler is started and stopped due to damage and blockage of parts is minimized, thereby maximizing the power production efficiency of a thermal power plant and significantly reducing maintenance costs.

[0034] According to one embodiment of the present invention, by supplying a portion of the air introduced into the outer passage to the inside through a plurality of first cooling holes on the front of the inner tube, it is possible to prevent clinker from accumulating in the inner passage and, at the same time, actively cool the base material where heat is concentrated to prevent thermal deformation.

[0035] According to one embodiment of the present invention, by having an expanded tube shape in which the ends of the inner tube and the outer tube widen as they move forward, it is possible to achieve the effect of widely and evenly spreading pulverized coal and combustion air into the furnace.

[0036] According to one embodiment of the present invention, by forming the corner regions of the inner tube and the outer tube by bending without welding, the thermal stress that would otherwise be concentrated at the welded part during thermal expansion is dispersed across the entire curved surface, thereby effectively preventing the occurrence of cracks at the source.

[0037] According to one embodiment of the present invention, by separating the fixing point of the bracket member connecting the inner tube and the outer tube so as not to overlap with the cooling hole location and optimizing the distance from the flame point to the rear, it is possible to prevent a decrease in the rigidity of the part assembly and maintain structural stability.

[0038] According to one embodiment of the present invention, by installing a lower reinforcing member in the form of a vertical plate between the lower surface of the dividing plate and the bottom surface of the inner tube, it is possible to mechanically prevent bending and sagging of the dividing plate caused by friction of pulverized coal and accumulation of solids.

[0039] According to one embodiment of the present invention, by forming a clad coating layer on the surfaces of an inner tube, a split plate, and a lower reinforcing member by spraying and heat-treating a nickel-based self-fluxing alloy, it is possible to improve wear resistance at high temperatures and minimize the slagging phenomenon in which coal solids stick.

[0040] According to one embodiment of the present invention, by firmly attaching a wear-resistant member to the foremost end of a split plate through a U-shaped coupling structure and a bonding fixing method, it is possible to achieve the effect of completely suppressing primary wear damage to the leading edge caused by high-speed straight-moving pulverized coal. Brief explanation of the drawing

[0042] Figure 1 schematically illustrates an example of a damaged conventional burner nozzle tip. FIG. 2 schematically illustrates a perspective view of a high-durability burner nozzle tip according to one embodiment of the present invention. FIG. 3 schematically illustrates a cross-sectional view of the area marked A-A' in FIG. 2. FIG. 4 schematically illustrates an inner discharge wing according to one embodiment of the present invention. FIG. 5 schematically illustrates a second outer body according to one embodiment of the present invention. FIG. 6 schematically illustrates an outer discharge wing according to one embodiment of the present invention. FIG. 7 illustrates details regarding CFD analysis of a high-durability burner nozzle tip according to one embodiment of the present invention. FIG. 8 schematically illustrates a right-side view of the area marked B in FIG. 2. FIG. 9 schematically illustrates a rear perspective view of a high-durability burner nozzle tip according to one embodiment of the present invention. FIG. 10 schematically illustrates a left side view of the area marked C in FIG. 9. FIG. 11 schematically illustrates a perspective view of a wear-resistant member according to another embodiment of the present invention. FIG. 12 schematically illustrates a perspective view of a split plate to which a wear-resistant member according to another embodiment of the present invention is applied. FIG. 13 schematically illustrates a perspective view of a split plate to which a wear-resistant member according to another embodiment of the present invention is applied. FIG. 14 schematically illustrates a micrograph of a clad coating layer according to one embodiment of the present invention. Specific details for implementing the invention

[0043] Hereinafter, various embodiments and / or aspects are disclosed with reference to the drawings. For illustrative purposes, numerous specific details are disclosed in the following description to aid in a general understanding of one or more aspects. However, it will also be recognized by those skilled in the art that these aspects may be practiced without such specific details. The following description and the accompanying drawings describe specific exemplary aspects of one or more aspects in detail. However, these aspects are exemplary, and some of the various methods in the principles of the various aspects may be used, and the description is intended to include all such aspects and their equivalents.

[0044] In addition, various aspects and features will be presented by a system that may include multiple devices, components and / or modules, etc. It should also be understood and recognized that various systems may include additional devices, components and / or modules, etc., and / or may not include all of the devices, components, modules, etc. discussed in relation to the drawings.

[0045] As used herein, terms such as "examples," "examples," "aspects," "examples," etc., may not be interpreted as implying that any aspect or design described is better or more advantageous than other aspects or designs.

[0046] Additionally, the terms “comprising” and / or “comprising” should be understood to mean that the relevant feature and / or component is present, but not to exclude the presence or addition of one or more other features, components and / or groups thereof.

[0047] Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any of a plurality of related described items.

[0048] Furthermore, in the embodiments of the present invention, all terms used herein, including technical or scientific terms, unless otherwise defined, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the embodiments of the present invention.

[0050] FIG. 2 schematically illustrates a perspective view of a high-durability burner nozzle tip (1) according to one embodiment of the present invention.

[0052] A high-durability burner nozzle tip (1) according to one embodiment of the present invention is a high-durability burner nozzle tip (1) applied to a boiler of a thermal power plant, and may include: an inner tube (100) that forms an inner passage (A1) through which pulverized coal moves and includes a plurality of first cooling holes (131) formed by penetrating a plurality of points; an outer tube (200) that is spaced apart from the inner tube (100) and forms an outer passage (A2) through which air moves and includes a plurality of second cooling holes (240) formed by penetrating a plurality of points; a dividing plate (300) disposed inside the inner tube (100) and partitioning the inner passage (A1); and a wear-resistant member (400) disposed inside the inner tube (100) and coupled to the end of the dividing plate (300) that is opposite to the direction in which pulverized coal flows.

[0054] The high-durability burner nozzle tip (1) is a core transfer facility that supplies pulverized coal and combustion air into the furnace of a boiler. Here, the boiler corresponds to a boiler of a thermal power plant, and preferably corresponds to a boiler of a coal-fired power plant.

[0055] The high-durability burner nozzle tip (1) is provided with a double-tube structure to withstand a harsh environment of high temperature, and the internal space of the inner tube body (100) located at the center forms an inner passage (A1) through which pulverized coal moves in the direction of the flame. An outer tube body (200) is arranged at a certain interval on the outside of the inner tube body (100), and the empty space between the inner tube body (100) and the outer tube body (200) forms an outer passage (A2) through which secondary air for combustion moves.

[0056] In the above configuration, when the boiler is operated, pulverized coal is introduced into the inner passage (A1) and discharged forward, while air is introduced into the outer passage (A2) and discharged forward, and at the same time, a portion of the air introduced into the outer passage (A2) can be supplied to the inside of the inner tube (100) through the plurality of first cooling holes (131).

[0057] At this time, as indicated by B, a bracket member (500) is installed between the spaced inner tube (100) and outer tube (200) to physically connect the two tubes and maintain a constant flow gap. The bracket member (500) will be described in more detail through the drawings to be described later.

[0059] In one embodiment of the present invention, the base material forming the inner tube (100) and the outer tube (200) comprises austenitic stainless steel, preferably comprising any one of SUS310, SUS310S, and SUS304.

[0060] High-temperature heat is concentrated near the front of each of the inner tube (100) and outer tube (200). It is preferable that a plurality of first cooling holes (131) and a plurality of second cooling holes (240) are perforated near the front of each of the inner tube (100) and outer tube (200) where high-temperature heat is concentrated.

[0061] Each of the plurality of first cooling holes (131) according to one embodiment of the present invention has a diameter of 5 to 15 mm, preferably 6 to 13 mm, and more preferably 10 mm. Each of the plurality of second cooling holes (240) according to one embodiment of the present invention has a diameter of 5 to 15 mm, preferably 6 to 13 mm, and more preferably 10 mm. The diameters of the plurality of first cooling holes (131) and the plurality of second cooling holes (240) correspond to diameters that prevent backflow of pulverized coal while cooling the base material and preventing clinker adhesion.

[0062] By means of the plurality of first cooling holes (131) and the plurality of second cooling holes (240) above, the high-durability burner nozzle tip (1) allows external air to be sucked in and flow through the plurality of second cooling holes (240) of the outer tube body (200) when the boiler is operated, and allows a portion of the air flowing through the outer passage (A2) to pass through the plurality of first cooling holes (131) of the inner tube body (100) and be supplied into the inner passage (A1). At this time, the portion of air passing through the plurality of first cooling holes (131) prevents the slagging phenomenon in which coal solids such as clinker adhere to and clog the inner wall of the inner tube body (100) through physical pressure. Additionally, the portion of air passing through the plurality of first cooling holes (131) cools the heat near the front of the inner tube body (100) to suppress thermal deformation.

[0063] That is, in one embodiment of the present invention, the high-durability burner nozzle tip (1) can prevent clinker from accumulating in the inner passage and simultaneously actively cool the base material where heat is concentrated by supplying a portion of the air introduced into the outer passage to the inside through a plurality of first cooling holes on the front of the inner tube body, thereby exhibiting the effect of preventing thermal deformation.

[0065] Each corner area of ​​the inner tube (100) and the outer tube (200) is formed by physically bending a continuous plate material into a rounded curved surface, completely excluding the welded part most vulnerable to high-temperature thermal deformation as shown in FIG. 2, and consists of an inner bent portion (132) and an outer bent portion (231).

[0066] Preferably, according to one embodiment of the present invention, the inner tube (100) may include an inner bend (132) formed at each corner area of ​​the front end of the inner passage (A1), and the outer tube (200) may include an outer bend (231) formed at each corner area of ​​the front end of the outer passage (A2). This bending shape structurally prevents the occurrence of corner cracks caused by concentrated stress by dispersing the uneven thermal expansion stress caused by flame radiation across the entire curved surface.

[0067] That is, by forming the corner areas of the inner tube (100) and the outer tube (200) by bending them without welding, the thermal stress that would have been concentrated in the welded area during thermal expansion is dispersed across the entire curved surface, thereby effectively preventing the occurrence of cracks at the source.

[0069] Meanwhile, in the internal space of the inner passage (A1) formed by the inner tube (100), a dividing plate (300) is arranged in the transverse direction to evenly control the flow of pulverized coal flowing in at high speed.

[0070] The above-described split plate (300) is configured to directly collide with pulverized coal particles, and a wear-resistant member (400) made of a ceramic material or the like is attached to the front end to primarily absorb and suppress wear damage to the base material caused by extreme particle friction at the forefront. Preferably, the wear-resistant member (400) may be either a ceramic material or a cemented carbide.

[0071] The above-mentioned wear-resistant member (400) will be described in more detail through the drawings described later.

[0073] In addition, a vertical lower reinforcing member (600) is installed vertically between the lower surface of the split plate (300) and the bottom surface of the inner tube (100) to firmly support the central lower part of the split plate (300).

[0074] Preferably, the high-durability burner nozzle tip (1) may further include a lower reinforcing member (600) installed between the bottom surface of the inner tube (100) and the lower surface of the dividing plate (300) to support the lower portion of the dividing plate (300). The lower reinforcing member (600) is made of a plate and, while positioned in a direction perpendicular to the bottom surface of the inner tube (100), its upper end surface is fixed to the lower surface of the dividing plate (300) and its lower end surface is fixed to the bottom surface of the inner tube (100).

[0075] In this way, in one embodiment of the present invention, by installing a lower reinforcing member (600) in the form of a vertical plate between the lower surface of the dividing plate (300) and the bottom surface of the inner tube (100), the effect of mechanically preventing bending and sagging of the dividing plate (300) caused by friction of fine coal and accumulation of solids can be achieved.

[0077] In other words, the high-durability burner nozzle tip (1) according to one embodiment of the present invention can exhibit the effect of dramatically extending the lifespan of the product by organically combining a cooling hole, a bending part, a lower reinforcing member (600), and a wear-resistant member (400) within a single nozzle tip structure, thereby simultaneously protecting against severe thermal damage such as cracks and thermal deformation and mechanical damage such as wear and sagging within the boiler furnace.

[0078] In addition, the high-durability burner nozzle tip (1) according to one embodiment of the present invention can minimize the number of times the boiler is started and stopped due to damage and blockage of parts, thereby maximizing the power production efficiency of the thermal power plant and significantly reducing maintenance costs.

[0080] FIG. 3 schematically illustrates a cross-sectional view of the area marked A-A' in FIG. 2, FIG. 4 schematically illustrates an inner discharge wing (130) according to one embodiment of the present invention, FIG. 5 schematically illustrates a second outer body (220) according to one embodiment of the present invention, and FIG. 6 schematically illustrates an outer discharge wing (230) according to one embodiment of the present invention.

[0082] According to one embodiment of the present invention, the inner tube (100) comprises: a first inner body (110) having a rectangular cross-section; a second inner body (120) that is bent and extended inwardly from one end of the first inner body (110) and becomes narrower in width toward the front; and an inner discharge wing (130) that is bent and extended outwardly from one end of the second inner body (120) and becomes wider in width toward the front; wherein the plurality of first cooling holes (131) may be formed by penetrating the inner discharge wing (130).

[0084] As illustrated in FIGS. 3 and 4, the inner tube (100) has a geometric shape that bends in multiple stages toward the front where the flame is ejected. Based on the A-A' cross-sectional view in FIG. 3, the inner tube (100) forms a tapered expansion structure in which the internal flow path starts from a straight first inner body (110), passes through a second inner body (120), temporarily narrows, and then widens again at the inner discharge wing (130) at the end.

[0085] In one embodiment of the present invention, the second inner body (120) may have both sides bent and extended inward from the front end of the first inner body (110) based on a front view or a perspective view, or both sides, the upper surface, and the lower surface may be bent and extended inward from the front end of the first inner body (110), but is not limited thereto and is preferably configured to include all forms such that the inner tube (100) has a structure in which the internal flow path temporarily narrows as it moves toward the front and then widens again at the end.

[0086] The shape of these inner discharge blades (130) controls the flow rate when a mixture of pulverized coal and air passes through a narrow flow path and enters the boiler furnace, and induces it to spread evenly in a wide fan shape, thereby maximizing combustion efficiency.

[0087] In other words, by having an expanded shape in which the end of the inner tube (100) widens as it goes forward, it is possible to achieve the effect of spreading pulverized coal and combustion air widely and evenly into the furnace.

[0089] A plurality of first cooling holes (131) are perforated in the inner discharge wing (130) that is most directly exposed to the high-temperature flame. In one embodiment of the present invention, the plurality of first cooling holes (131) serve to allow a portion of the air flowing into the outer passage (A2) to flow into the inner passage (A1).

[0090] In addition, the inner tube (100) is formed such that each corner area of ​​the inner discharge wing (130) is formed as an inner folded portion (132) in which the plate material is continuously bent and the welded seam is excluded, thereby eliminating the thermal stress limit point.

[0091] Preferably, an inner tube (100) according to one embodiment of the present invention may include: a first inner body (110) having a rectangular cross-section; a second inner body (120) that is bent and extended inwardly from one end of the first inner body (110) and becomes narrower in width toward the front; and an inner discharge wing (130) that is bent and extended outwardly from one end of the second inner body (120), becomes wider in width toward the front, and has an inner bent portion (132) formed in each corner area.

[0093] According to one embodiment of the present invention, the outer tube (200) comprises: a first outer body (210) having a rectangular cross-section; a second outer body (220) that is bent and extended inwardly from one end of the first outer body (210) and becomes narrower in width toward the front; and an outer discharge wing (230) that is bent and extended outwardly from one end of the second outer body (220) and becomes wider in width toward the front; and the plurality of second cooling holes (240) may be formed by penetrating the second outer body (220) and the outer discharge wing (230).

[0095] As illustrated in FIGS. 3, 5, and 6, the outer tube (200) has a shape in which the aforementioned inner tube (100) is offset outward. More specifically, the outer tube (200) has a geometric shape that bends in multiple stages toward the front where the flame is ejected. Based on the A-A' cross-sectional view in FIG. 3, the outer tube (200) starts from a straight first outer body (210), narrows as it goes toward a second outer body (220) that bends inward, and forms a tapered expansion structure at the outer discharge wing (230) that bends outward again at the end.

[0096] In one embodiment of the present invention, the second outer body (220) may have both sides bent and extended inward from the front end of the first outer body (210) based on a front view or a perspective view, or both sides, the upper surface, and the lower surface may be bent and extended inward from the front end of the first outer body (210), but is not limited thereto and is preferably configured to include all forms such that the outer tube (200) has a structure in which the internal flow path temporarily narrows as it moves toward the front and then widens again at the end.

[0097] In addition, in one embodiment of the present invention, the first outer body (210) preferably includes all shapes having a rectangular cross-section.

[0098] The shape of these outer discharge blades (230) controls the flow rate when the mixture of pulverized coal and air that has passed through the narrow flow path enters the boiler furnace and induces it to spread evenly in a wide fan shape, thereby maximizing combustion efficiency.

[0099] In other words, by having an expanded shape in which the end of the outer tube (200) widens as it goes forward, it is possible to achieve the effect of spreading pulverized coal and combustion air widely and evenly into the furnace.

[0101] In the outer tube (200), a plurality of second cooling holes (240) are perforated in the outer discharge wing (230) and the second outer body (220), which are most directly exposed to the high-temperature flame. In one embodiment of the present invention, the plurality of second cooling holes (240) serve to smoothly disperse and flow external air into the outer passage (A2), and the external air is introduced from a location including the upper and lower parts of the high-durability burner nozzle tip (1).

[0102] In addition, the outer tube (200) is formed such that each corner area of ​​the outer discharge wing (230) is formed as an outer folded portion (231) in which the plate material is continuously bent and the welded seam is excluded, thereby eliminating the thermal stress limit point.

[0103] Preferably, an outer tube (200) according to one embodiment of the present invention may include: a first outer body (210) having a rectangular cross-section; a second outer body (220) that is bent and extended inwardly from one end of the first outer body (210) and becomes narrower in width toward the front; and an outer discharge wing (230) that is bent and extended outwardly from one end of the second outer body (220), becomes wider in width toward the front, and has an outer bent portion (231) formed in each corner area.

[0105] Meanwhile, in accordance with one embodiment of the present invention, the high-durability burner nozzle tip (1) may have a clad coating layer (700) formed by heat treatment after spraying a self-fluxing alloy onto the inner surface of the inner tube (100).

[0106] According to one embodiment of the present invention, the high-durability burner nozzle tip (1) may have a clad coating layer (700) formed by heat treatment after spraying a self-fluxing alloy onto the surface of the dividing plate (300).

[0107] In one embodiment of the present invention, the high-durability burner nozzle tip (1) may have a clad coating layer (700) formed by heat treatment after spraying a self-fluxing alloy onto the surface of the dividing plate (300) and the surface of the lower reinforcing member (600).

[0108] Preferably, the high-durability burner nozzle tip (1) according to one embodiment of the present invention may have a clad coating layer (700) formed by heat treatment after spraying a self-fluxing alloy onto the front surface.

[0110] As illustrated in FIG. 3, the high-durability burner nozzle tip (1) has a clad coating layer (700) formed on the inner surface of the inner tube body (100) and on the surface of the dividing plate (300). Although not illustrated in FIG. 3, it is preferable that the clad coating layer (700) be formed throughout the internal flow path that comes into contact with the fluid.

[0111] In addition, the clad coating layer (700) may be formed on the front outer surface of the outer tube (200) as shown in FIG. 3, according to an embodiment.

[0112] Meanwhile, although not illustrated in FIG. 3, the clad coating layer (700) may be formed on the front surface of the high-durability burner nozzle tip (1). In this case, it is preferable that the front surface includes a front surface facing the flame point from the high-durability burner nozzle tip (1) and an area with a width of approximately 150 mm in all directions (up, down, left, and right).

[0113] The above clad coating layer (700) is formed by first spray-coating a self-fluxing alloy containing Ni components onto the surface of a base material and then heat-treating it to melt it again at a high temperature. More specifically, the above clad coating layer (700) is formed by coating powder of the self-fluxing alloy onto the surface of a base material using an oxygen / acetylene spray-coating technique and then heat-treating it in a vacuum furnace. At this time, the heat treatment temperature in the vacuum furnace is preferably 1000°C or higher, and preferably 1100°C or higher.

[0114] This method induces a diffusion bonding phenomenon in which the powder of the self-fluxing alloy diffuses and penetrates into the metal lattice of the base material and fuses, so the physical bonding strength of the interface is significantly higher than that of a conventional build-up welding coating. Through this, the high-durability burner nozzle tip (1) of the present invention does not peel off even in a high-temperature operating environment, and not only improves wear resistance by maximizing surface hardness, but also provides an excellent anti-slagging coating surface that allows molten coal solids to slide off without sticking to the surface.

[0115] In one embodiment of the present invention, the self-fluxing alloy may comprise C, Cr, W, Co, B, and Ni, and preferably, the self-fluxing alloy may comprise 0.8 to 2.6% C, 8.0 to 16.0% Cr, 25.0 to 50.0% W, 2.0 to 6.0% Co, 0.5 to 3.2% B, and the remainder Ni, and more preferably, the self-fluxing alloy may comprise 1.64% C, 15.8% Cr, 28.1% W, 2.79% Co, 2.26% B, and 46.0% Ni.

[0116] In other words, in one embodiment of the present invention, by forming a clad coating layer (700) on the surface of the inner tube (100), the split plate (300), and the lower reinforcing member (600) by spraying and heat-treating a nickel-based self-fluxing alloy, it is possible to improve wear resistance at high temperatures and minimize the slagging phenomenon in which coal solids stick.

[0118] FIG. 7 illustrates details regarding CFD analysis for a high-durability burner nozzle tip (1) according to one embodiment of the present invention.

[0120] As shown in FIG. 7, computational fluid dynamics (CFD) analysis results confirm that the plurality of first cooling holes (131) and second cooling holes (240) can perform an active cooling action that substantially lowers the temperature of the high-durability burner nozzle tip (1).

[0121] More specifically, the redder the color in the drawing, the higher the temperature of the product surface, and it can be seen that the temperature of the front part of the inner tube (100) and the outer tube (200) is significantly reduced when cooling holes are applied (Fig. 7 (a) and Fig. 7 (b)) compared to when cooling holes are not perforated (Fig. 7 (c)). This means that as a portion of the combustion air flowing through the outer passage (A2) is sprayed toward the inner passage (A1) through the first cooling hole (131), the thermal stress around the inner fold (132) and the outer fold (231), where harsh flame radiant heat of 1000°C or more is concentrated, is effectively relieved and thermal deformation is reduced.

[0122] At this time, it is preferable that each of the plurality of first cooling holes (131) and the plurality of second cooling holes (240) have a diameter of 5 to 15 mm. If the diameter of each of the plurality of first cooling holes (131) and the plurality of second cooling holes (240) is less than 5 mm, the air flow rate is insufficient, making it difficult to obtain the desired effects of cooling the base material and preventing clinker adhesion. If the diameter of each of the plurality of first cooling holes (131) and the plurality of second cooling holes (240) exceeds 15 mm, there is a risk that the pulverized coal particles flowing through the inner passage (A1) may flow back toward the outer passage (A2) or that the overall flow balance may be disrupted, thereby reducing combustion efficiency.

[0123] In this way, the thermal deformation suppression effect through the cooling hole creates a powerful synergy effect that enables all the elements constituting the high-durability burner nozzle tip (1), including the split plate (300), the wear-resistant member (400) that defends against impact of fine coal, the bracket member (500) that maintains the spacing of the tube, the lower reinforcing member (600) that supports load deflection, and the clad coating layer (700) that prevents erosion of the base material surface, to maintain their inherent mechanical performance for a long period without thermal fatigue.

[0125] FIG. 8 schematically illustrates a right-side view of the area marked B in FIG. 2.

[0127] A high-durability burner nozzle tip (1) according to one embodiment of the present invention may further include a bracket member (500) that connects the inner tube (100) and the outer tube (200) by fixing one end to the outer surface of the inner tube (100) and fixing the other end to the inner surface of the outer tube (200).

[0129] As illustrated in FIG. 8, the high-durability burner nozzle tip (1) includes a bracket member (500) that physically and firmly connects the two tubes to maintain a constant spaced-apart space between the inner tube (100) and the outer tube (200).

[0130] One end of the bracket member (500) is fixed to the outer surface of the inner tube body (100), and the other end is assembled to the inner surface of the outer tube body (200) to ensure overall rigidity. The bracket member (500), together with the aforementioned lower reinforcing member (600), corresponds to a configuration that allows the high-durability burner nozzle tip (1) to maintain its overall frame even when heavy pulverized coal and slag are deposited.

[0132] Meanwhile, in an environment where high-temperature flames are applied, the fixed point of the bracket member (500) can become a vulnerable part where thermal stress is most easily concentrated and cracks may occur.

[0133] In order to prevent this, in the present invention, each end-side fixing point and the other end-side fixing point, where the bracket member (500) is fixed to the inner tube body (100) and the outer tube body (200), are positioned at a location spaced apart in the up, down, left, and right directions so as not to physically overlap with the plurality of perforated first cooling holes (131) and the plurality of second cooling holes (240).

[0134] Preferably, according to one embodiment of the present invention, the bracket member (500) is fixed to the outer surface of the inner tube (100), and each of the first cooling holes (131) is formed at a spaced-apart position so as not to physically overlap each other, and the other end fixing point and each of the second cooling holes (240) are fixed to the inner surface of the outer tube (200) so as not to physically overlap each other.

[0135] Through this, the high-durability burner nozzle tip (1) according to one embodiment of the present invention fundamentally prevents structural destruction caused by thermal fatigue by welding and joining the bracket member (500) while avoiding the stress concentration area around the cooling hole.

[0137] In addition, in one embodiment of the present invention, the bracket member (500) is fixed at a position further back than the foremost end surface of the inner tube (100) and the outer tube (200). More specifically, as shown in FIG. 8, the bracket member (500) is fixed at a position where the distance (L1) from the flame point to the end surface of the bracket member (500) is longer than the distance (L2) from the flame point to the end surface of the inner tube and the distance (L3) from the flame point to the end surface of the outer tube.

[0138] Preferably, when a flame point is located on the front side of the high-durability burner nozzle tip (1), the distance from the flame point to the front end surface of the bracket member is longer than the distance from the flame point to the front end surface of the inner tube, and the distance from the flame point to the front end surface of the bracket member is longer than the distance from the flame point to the front end surface of the outer tube.

[0139] In this way, by keeping the bracket member (500) as far as possible from the direct influence zone of flame radiant heat, the phenomenon of reduced rigidity where the core component connecting the pipe body expands or melts due to high heat is prevented, and the overall structural stability of the high-durability burner nozzle tip (1) can be maintained for a long time.

[0141] In addition, in one embodiment of the present invention, the high-durability burner nozzle tip (1) includes a lower reinforcing member (600) installed vertically between the bottom surface of the inner tube (100) and the lower surface of the dividing plate (300), in addition to a lateral support structure through a bracket member (500). The lower reinforcing member (600) mechanically and strongly supports the dividing plate (300) so that it does not sag downward or break even if heavy pulverized coal and slag are deposited, and performs a key role in maintaining the overall framework inside the nozzle tip firmly together with the bracket member (500).

[0143] In other words, in one embodiment of the present invention, by separating the fixing point of the bracket member (500) connecting the inner tube (100) and the outer tube (200) so as not to overlap with the cooling hole location and optimizing the distance from the flame point to the rear, it is possible to prevent a decrease in the rigidity of the part assembly and maintain structural stability.

[0145] FIG. 9 schematically illustrates a rear perspective view of a high-durability burner nozzle tip (1) according to one embodiment of the present invention, and FIG. 10 schematically illustrates a left side view of the area marked C in FIG. 9.

[0147] The wear-resistant member (400) according to one embodiment of the present invention may include: an upper fixing part (410) located on the upper side of the dividing plate (300); a collision part (420) formed extending downward from one end of the upper fixing part (410) and having an outer surface formed convexly toward the rear of the inner passage (A1); and a lower fixing part (430) formed extending forward from one end of the collision part (420) and located on the lower side of the dividing plate (300).

[0149] The above high-durability burner nozzle tip (1) controls the flow direction of pulverized coal flowing in from the rear side using a split plate (300) inside an inner tube (100). At this time, pulverized coal particles incident at high speed in a straight line cause severe physical damage to the leading edge of the split plate (300). To defend against this, the high-durability burner nozzle tip (1) of the present invention has a structure in which a wear-resistant member (400) is attached to the end of the split plate (300) that is opposite to the direction in which the pulverized coal flows in.

[0150] The wear-resistant member (400) is installed at one end of the split plate (300) to prevent pulverized coal from directly colliding with the split plate (300). Since pulverized coal directly collides with the wear-resistant member (400), it is made of a material that is highly durable against wear damage. The material of the wear-resistant member (400) is preferably a high-hardness material such as a ceramic material or a cemented carbide. Examples of ceramic materials include silicon carbide, alumina, and mixtures of alumina and zirconia, and examples of cemented carbides include WC (tungsten carbide), but the material of the wear-resistant member (400) is not necessarily limited to these examples.

[0151] The above-described wear-resistant member (400) is composed of an upper fixing part (410) covering the upper surface of the dividing plate (300), a collision part (420) that directly collides with pulverized coal, and a lower fixing part (430) that supports the lower surface of the dividing plate (300), thereby forming a cross-section in the shape of a U. Preferably, the above-described wear-resistant member (400) forms a U-shaped cross-section by the upper fixing part (410), the collision part (420), and the lower fixing part (430), and the end side of the dividing plate (300) facing the direction in which pulverized coal flows in can be accommodated in the inner space of the U-shaped cross-section.

[0152] In the above configuration, the collision part (420) is formed to protrude in a convex curved shape toward the direction in which the pulverized coal is introduced, thereby inducing the impact energy of the high-speed straight-moving pulverized coal particles to be deflected in both upward and downward directions, which can effectively reduce fluid resistance and frictional damage.

[0154] In addition, the high-durability burner nozzle tip (1) is equipped with a robust assembly structure so that the wear-resistant member (400) does not detach from the split plate (300) even in a harsh boiler environment where vibration and thermal expansion are repeated.

[0155] In one embodiment of the present invention, the upper fixing part (410) has a fixing projection part (411) formed at its end that bends vertically toward the surface of the dividing plate (300) to provide a mechanical locking structure. Preferably, the upper fixing part (410) may include a fixing projection part (411) formed to protrude from the other end toward the dividing plate (300). Additionally, a high-temperature bond (440) is applied to the area where the inner space of the C-shape of the wear-resistant member (400) and the dividing plate (300) come into contact. Preferably, the wear-resistant member (400) has a bond (440) applied to the inner space of the U-shaped cross section, and while the bond (440) is applied to the inner space of the U-shaped cross section, the end side of the split plate (300) facing the direction in which pulverized coal flows in is received in the inner space of the U-shaped cross section and can be fixed to each other.

[0156] Through a double fixing method combining the physical structure of the fixed protrusion (411) and the chemical bonding of the bond (440), the wear-resistant member (400) primarily and completely absorbs and protects against the wear phenomenon of the base material of the split plate (300) without detachment even in high-speed airflow and vibration.

[0158] That is, in one embodiment of the present invention, by firmly attaching a wear-resistant member (400) to the foremost end of the split plate (300) through a U-shaped coupling structure and a bonding fixing method, the effect of completely suppressing primary wear damage to the leading edge caused by high-speed straight-moving pulverized coal can be achieved.

[0160] FIG. 11 schematically illustrates a perspective view of a wear-resistant member (400) according to another embodiment of the present invention, and FIG. 12 and FIG. 13 schematically illustrate a perspective view of a split plate (300) to which the wear-resistant member (400) according to another embodiment of the present invention is applied.

[0162] The shape of the upper fixing part (410) and the lower fixing part (430) can be determined by considering factors such as the shape of the split plate (300), ease of detachment of the wear-resistant member (400), and effective protection of the split plate (300).

[0163] For example, as shown in FIG. 11, the outer surface of the impact portion (420) of the wear-resistant member (400) may have a convex curved shape. Since the outer surface in contact with the pulverized coal has a convex curved shape, the wear-resistant member (400) and the split plate (300) can be effectively protected from the impact of the pulverized coal traveling at high speed and straight.

[0165] As shown in FIG. 12, it is preferable that the wear-resistant member (400) be installed in close contact with one side of the dividing plate (300), but the present invention is not necessarily limited to the wear-resistant member (400) and the dividing plate (300) being installed in close contact.

[0166] FIGS. 12 and 13 illustrate a T-shaped split plate (300) including a body plate (310) and a wing plate (320) that cross the center of an inner passage (A1), but the shape of the split plate (300) is not necessarily limited to this.

[0167] Additionally, a single integrated wear-resistant member (400) may be installed in the split plate (300), but as shown in FIG. 12, a plurality of divided wear-resistant members (400) may also be installed. A plurality of divided wear-resistant members (400) may be installed side by side at the rear of the body plate (310) and the wing plate (320), respectively. In the case of a plurality of divided wear-resistant members (400), the wear-resistant member (400) can be easily attached to and detached from the split plate (300), and if wear is concentrated in a specific area due to flow characteristics, it is possible to individually replace only the wear-resistant member (400) where the wear is concentrated, thereby improving maintainability.

[0169] As shown in FIG. 13, a groove and a protrusion are formed in the joint portion of the wear-resistant member (400) and the split plate (300), and the wear-resistant member (400) can be firmly installed on one side of the split plate (300) by inserting the protrusion into the groove.

[0170] More specifically, in another embodiment of the present invention, a first projection (412) may be formed protrudingly on one or more of the upper fixing part (410) and the lower fixing part (430), and a first groove (330) may be formed recessed in a shape corresponding to the first projection (412) on one side of the dividing plate (300). In this case, the first projection (412) is inserted into the first groove (330), and the wear-resistant member (400) is mounted on the dividing plate (300). Although FIGS. 11 to 13 show the first projection (412) being formed protrudingly on the upper fixing part (410), it may include the first projection (412) being formed protrudingly on the inner side of the collision part (420).

[0171] In addition, in another embodiment of the present invention, a second protrusion (340) may be formed protrudingly on one or more of the upper and lower surfaces of the split plate (300), and a second groove (413) may be formed in a shape corresponding to the second protrusion (340) on one surface of the upper fixing part (410) or the lower fixing part (430). In this case, the second protrusion (340) is inserted into the second groove (413), and the wear-resistant member (400) is mounted on the split plate (300). Although FIG. 13 (b) shows the second groove (413) being formed in a recess on one surface of the upper fixing part (410), it may include the second groove (413) being formed in a recess on the inner surface of the collision part (420).

[0172] In addition, in another embodiment of the present invention, a first groove (330) may be formed only on one side of the dividing plate (300), and a first projection (412) may be formed only on one side of the corresponding upper fixing part (410). Also, although not shown in the drawings, according to the embodiment, a second groove (413) may be formed only on one side of the upper fixing part (410), and a second projection (340) may be formed only on one side of the corresponding dividing plate (300).

[0173] In addition, in another embodiment of the present invention, as shown in FIG. 13, a first protrusion (412) may be formed on a plurality of surfaces of a plurality of wear-resistant members (400), and a first groove (330) may be formed on a plurality of surfaces of a corresponding dividing plate (300). Although not shown in the drawings, according to the embodiment, a second protrusion (340) may be formed on a plurality of surfaces of a dividing plate (300), and a second groove (413) may be formed on each of a plurality of upper fixing parts (410) and lower fixing parts (430).

[0175] FIG. 14 schematically illustrates a micrograph of a clad coating layer (700) according to one embodiment of the present invention.

[0177] As described above, in one embodiment of the present invention, the clad coating layer (700) corresponds to a configuration formed by heat treatment after thermal spraying a self-fluxing alloy.

[0178] Figure 14(a) schematically illustrates a micrograph of the thermal spray coating layer formed after thermal spraying a self-fluxing alloy. As shown in Figure 14(a), the thermal spray coating layer contains internal pores (black dots) with an area ratio of approximately 15%, and areas (black lines) where adhesion between the base material and the coating layer is not achieved and the layers are partially separated can be observed.

[0179] FIG. 14(b) schematically illustrates a microscopic image of a clad coating layer formed after heat treatment of the thermal spray coating layer. As shown in FIG. 14(b), unlike the thermal spray coating layer of FIG. 14(a), the clad coating layer (700) has internal pores of less than 1% of the area ratio and can be seen to have a relatively dense structure with no discontinuities between the base material and the coating layer.

[0180] This means that the above-mentioned clad coating layer (700) has a dense structure with the base material compared to the above-mentioned thermal spray coating layer that has not undergone heat treatment after thermal spray coating.

[0182] According to one embodiment of the present invention, by organically combining a cooling hole, a bending portion, a lower reinforcing member, and a wear-resistant member within a single nozzle tip structure, it is possible to simultaneously protect against severe thermal damage such as cracks and thermal deformation and mechanical damage such as wear and sagging within the boiler furnace, thereby dramatically extending the product's lifespan.

[0183] According to one embodiment of the present invention, the number of times a boiler is started and stopped due to damage and blockage of parts is minimized, thereby maximizing the power production efficiency of a thermal power plant and significantly reducing maintenance costs.

[0184] According to one embodiment of the present invention, by supplying a portion of the air introduced into the outer passage to the inside through a plurality of first cooling holes on the front of the inner tube, it is possible to prevent clinker from accumulating in the inner passage and, at the same time, actively cool the base material where heat is concentrated to prevent thermal deformation.

[0185] According to one embodiment of the present invention, by having an expanded tube shape in which the ends of the inner tube and the outer tube widen as they move forward, it is possible to achieve the effect of widely and evenly spreading pulverized coal and combustion air into the furnace.

[0186] According to one embodiment of the present invention, by forming the corner regions of the inner tube and the outer tube by bending without welding, the thermal stress that would otherwise be concentrated at the welded part during thermal expansion is dispersed across the entire curved surface, thereby effectively preventing the occurrence of cracks at the source.

[0187] According to one embodiment of the present invention, by separating the fixing point of the bracket member connecting the inner tube and the outer tube so as not to overlap with the cooling hole location and optimizing the distance from the flame point to the rear, it is possible to prevent a decrease in the rigidity of the part assembly and maintain structural stability.

[0188] According to one embodiment of the present invention, by installing a lower reinforcing member in the form of a vertical plate between the lower surface of the dividing plate and the bottom surface of the inner tube, it is possible to mechanically prevent bending and sagging of the dividing plate caused by friction of pulverized coal and accumulation of solids.

[0189] According to one embodiment of the present invention, by forming a clad coating layer on the surfaces of an inner tube, a split plate, and a lower reinforcing member by spraying and heat-treating a nickel-based self-fluxing alloy, it is possible to improve wear resistance at high temperatures and minimize the slagging phenomenon in which coal solids stick.

[0190] According to one embodiment of the present invention, by firmly attaching a wear-resistant member to the foremost end of a split plate through a U-shaped coupling structure and a bonding fixing method, it is possible to achieve the effect of completely suppressing primary wear damage to the leading edge caused by high-speed straight-moving pulverized coal.

[0192] Although the embodiments have been described above with reference to limited examples and drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results may be achieved even if the described techniques are performed in a different order than described, and / or if the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents. Therefore, other implementations, other embodiments, and equivalents to the claims below are also within the scope of the claims. Explanation of the symbols

[0194] 1: High-durability burner nozzle tip 100: Inner tube 110: First inner body 120: Second inner body 130: Inner discharge blade 131: First cooling hole 132: Inner bend 200: Outer tube 210: First outer body 220: Second outer body 230: Outer discharge blade 231: Outer bend 240: Second cooling hole 300: Split plate 310: Body plate 320: Wing plate 330: First groove 340: Second projection 400: Wear-resistant member 410: Upper fixing part 411: Fixed projection 412: First projection 413: Second groove section 420: Collision section 430: Lower fixing part 440: Bond 500: Bracket member 600: Lower reinforcing member 700: Clad coating layer A1: Medial passage A2: Lateral passage

Claims

Claim 1 A high-durability burner nozzle tip applied to a boiler of a thermal power plant, comprising: an inner tube body forming an inner passage through which pulverized coal moves and including a plurality of first cooling holes formed by penetrating a plurality of points; an outer tube body spaced apart from the outer side of the inner tube body, forming an outer passage through which air moves and including a plurality of second cooling holes formed by penetrating a plurality of points; a dividing plate disposed inside the inner tube body to partition the inner passage; and a wear-resistant member disposed inside the inner tube body and coupled to the end of the dividing plate facing the direction in which pulverized coal flows in; wherein, when the boiler operates, pulverized coal flows into the inner passage and is discharged forward, while air flows into the outer passage and is discharged forward, and simultaneously, a portion of the air flowing into the outer passage is supplied to the inner side of the inner tube body through the plurality of first cooling holes. Claim 2 A high-durability burner nozzle tip according to claim 1, wherein the inner tube comprises: a first inner body having a square cross-section; a second inner body that is bent and extended inwardly from one end of the first inner body and becomes narrower towards the front; and an inner discharge wing that is bent and extended outwardly from one end of the second inner body and becomes wider towards the front, wherein the plurality of first cooling holes are formed by penetrating the inner discharge wing. Claim 3 A high-durability burner nozzle tip according to claim 1, wherein the outer tube comprises: a first outer body having a square cross-section; a second outer body that is bent and extended inwardly from one end of the first outer body and becomes narrower towards the front; and an outer discharge wing that is bent and extended outwardly from one end of the second outer body and becomes wider towards the front, wherein the plurality of second cooling holes are formed by penetrating the second outer body and the outer discharge wing. Claim 4 A high-durability burner nozzle tip according to claim 1, wherein the inner tube body comprises an inner bend formed in each corner area of ​​the front end of the inner passage; and the outer tube body comprises an outer bend formed in each corner area of ​​the front end of the outer passage. Claim 5 A high-durability burner nozzle tip according to claim 1, wherein the inner tube comprises: a first inner body having a square cross-section; a second inner body that is bent and extended inwardly from one end of the first inner body and becomes narrower in width toward the front; and an inner discharge wing that is bent and extended outwardly from one end of the second inner body, becomes wider in width toward the front, and has an inner bent portion formed in each corner area. Claim 6 A high-durability burner nozzle tip according to claim 1, wherein the outer tube comprises: a first outer body having a square cross-section; a second outer body that is bent and extended inwardly from one end of the first outer body and becomes narrower in width toward the front; and an outer discharge wing that is bent and extended outwardly from one end of the second outer body, becomes wider in width toward the front, and has an outer bent portion formed in each corner area. Claim 7 The high-durability burner nozzle tip of claim 1 further comprises a bracket member connecting the inner tube and the outer tube, wherein one end of the high-durability burner nozzle tip is fixed to the outer surface of the inner tube and the other end is fixed to the inner surface of the outer tube. Claim 8 A high-durability burner nozzle tip according to claim 7, wherein each of the one-sided fixing point where the bracket member is fixed to the outer surface of the inner tube and the plurality of first cooling holes are formed at a spaced position so as not to physically overlap each other, and each of the other-sided fixing point where the bracket member is fixed to the inner surface of the outer tube and the plurality of second cooling holes are formed at a spaced position so as not to physically overlap each other. Claim 9 The high-durability burner nozzle tip of claim 1 further comprises a lower reinforcing member installed between the bottom surface of the inner tube and the lower surface of the dividing plate to support the lower part of the dividing plate. Claim 10 A high-durability burner nozzle tip according to claim 9, wherein the lower reinforcing member is made of a plate, and is arranged in a direction perpendicular from the bottom surface of the inner tube, with the upper end surface fixed to the lower surface of the dividing plate and the lower end surface fixed to the bottom surface of the inner tube. Claim 11 A highly durable burner nozzle tip according to claim 1, wherein each of the plurality of first cooling holes has a diameter of 5 to 15 mm. Claim 12 A highly durable burner nozzle tip according to claim 1, wherein each of the plurality of second cooling holes has a diameter of 5 to 15 mm. Claim 13 In claim 1, the high-durability burner nozzle tip is a high-durability burner nozzle tip in which a clad coating layer is formed by heat-treating the inner surface of the inner tube body after spray-coating a self-fluxing alloy. Claim 14 In claim 1, the high-durability burner nozzle tip is a high-durability burner nozzle tip in which a clad coating layer is formed by heat treatment after thermally spraying a self-fluxing alloy onto the surface of the dividing plate. Claim 15 In claim 9, the high-durability burner nozzle tip is a high-durability burner nozzle tip in which a clad coating layer is formed by heat treatment after spraying a self-fluxing alloy onto the surface of the dividing plate and the surface of the lower reinforcing member. Claim 16 A highly durable burner nozzle tip according to claim 13, claim 14, or claim 15, wherein the self-fluxing alloy comprises Ni. Claim 17 A high-durability burner nozzle tip according to claim 1, wherein the wear-resistant member is either a ceramic material or a cemented carbide. Claim 18 A high-durability burner nozzle tip according to claim 1, wherein the wear-resistant member comprises: an upper fixing part located on the upper side of the dividing plate; a collision part extending downward from one end of the upper fixing part and having an outer surface formed convexly toward the rear of the inner passage; and a lower fixing part extending forward from one end of the collision part and located on the lower side of the dividing plate. Claim 19 A high-durability burner nozzle tip according to claim 18, wherein the wear-resistant member forms a U-shaped cross-section by means of the upper fixing part, the impact part, and the lower fixing part, and the end side facing the direction in which pulverized coal flows among the ends of the split plate is accommodated in the inner space of the U-shaped cross-section. Claim 20 A high-durability burner nozzle tip according to claim 19, wherein the wear-resistant member has a bond applied to the inner space of the U-shaped cross-section, and while the bond is applied to the inner space of the U-shaped cross-section, the end side of the end of the split plate facing the direction in which pulverized coal flows is received in the inner space of the U-shaped cross-section and fixed to each other.

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