UA113544U - LASER OPENING INSTALLATION - Google Patents

Abstract

The laser hole treatment unit comprises a laser, an optical system, a workpiece placement table and a device for changing the relative position of the radiation caustic beam and the workpiece surface. The device is made in the form of a hole in the table to accommodate the workpiece connected to the compressed air network through the inlet diaphragm, which is coaxial with the axis of the laser beam and has a longitudinal profile with a variable cross section, and its dimensions from the side of the laser radiation and EMBED Equation.3. from the workpiece EMBED Equation.3 are related to the workpiece diameter EMBED Equation.3 by the ratio: EMBED Equation.3.

Description

The field of technology

The invention relates to a solid fuel burner, and more specifically, to a burner that provides low nitrogen oxide (NOx) combustion with exceptional solid fuel efficiency.

Technical level

In general, the cross-section of the outlet part of the fuel nozzle of a solid fuel burner has a shape close to a circle or a square, and a considerable distance is required for the flame that ignites the fuel jet from the outside to spread to the central part of this jet in some situations. The distance along which the flame for ignition in the direction of the fuel jet from the fuel nozzle spreads to the central part of the fuel jet, that is, the non-ignition distance increases as the diameter or outer diameter of the fuel nozzle increases and the unignited zone increases. Maintaining combustion in the recovery zone near the burner is important to suppress MOH generation in gaseous combustion products, but increasing the unburnt zone means reducing the post-ignition burning time, and this may be the cause of insufficient MOH suppression or reduced combustion efficiency.

In a boiler room equipped with many solid fuel burners as combustion devices, although increasing the burner capacity is an effective technique to improve performance based on reducing the cost and reducing the number of burners, there is a problem that the diameter or length of the outer part of each fuel nozzle increases and the unburned area increases, which leads to an increase in MOH and a decrease in combustion efficiency.

This problem is due to the large distance from the combustion zone on the surface of the fuel jet to the central part of this jet.

MO2008-038426A1 (hereinafter: "patent literature 1") describes the invention, which is the state of the art of the invention of this applicant, where the non-ignition zone is reduced and at the same time the power of the burner is increased due to the fact that the shape of the outlet hole in the cross section of the fuel nozzle section is rectangular, which has a part with a long side and a part with a short side, an elliptical shape, or, in fact, an elliptical shape, and the prevention of an increase in the concentration of MOX in the gaseous products of combustion and a decrease in the efficiency of fuel combustion is achieved.

In addition, ММО2009-125566А1 discloses an open shape of the burner, similar to the shape in the above invention.

In addition, in the boiler room, in the case where the liquid moves along the passage to use the steam obtained by heating the liquid, which flows through many heat exchange pipes, heating occurs with the help of high-temperature exhaust gas, which is provided by solid fuel burners in the boiler furnace. The passage for steam recirculation, obtaining the transfer of a certain amount of heat to the liquid in the heat exchange part, where each heat exchange pipe is installed, is complex, and the temperature of the gaseous products of combustion and the flow rate of the liquid, which must be controlled in each heat exchange part, are important. Therefore, the invention can provide control of the amount of heat transfer to the liquid in each heat exchange pipe by changing the position of the fuel combustion flame in the boiler (M/02009-041081А1). In the example of the invention, the outlet of the nozzle for a gas jet in a solid fuel burner is divided into two: upper and lower - parts, and by independently adjusting the corresponding air flow speeds, it is possible to ensure a change in the position of the fuel combustion flame vertically.

It should be noted that in a boiler that uses solid fuel, as a rule, the solid fuel is pulverized coal, and, therefore, such a boiler can be called a pulverized coal boiler, and the solid fuel burner will be called a pulverized coal burner. At the moment of starting the pulverized coal boiler, the fans are activated and air is supplied as fuel gas to the plurality of pulverized coal burners installed in the furnace of the boiler and the two-stage ports for fuel air. Then, a flame is formed in the ignition nozzle of each pilot burner and the flame detector (hereinafter, "DP" detects this flame, then liquid fuel is injected from each pilot burner, which is ignited by the flame 3 from each pilot nozzle, and is created flame in each pilot burner After the flame detector detects the formation of a flame used by the pilot burner, the flame of each igniter nozzle is extinguished and the igniter nozzle is removed from the side of the outer furnace to prevent it from burning out.

Next, the furnace temperature is increased by the starter burner until the furnace exit temperature reaches the set point, and the crusher is activated to gradually switch to burning pulverized coal. That is, in each pulverized coal burner, in order to ignite pulverized coal, a starter burner is installed, which uses liquid or the like. fuel, and additionally installed is an ignition nozzle that ignites this pilot burner and a flame detector that detects the flame.

As pulverized coal burners, a pulverized coal burner is used, which has a pilot burner installed in the center and allows pulverized coal and primary air as a carrier gas to flow from the periphery of the pilot burner and be discharged into the furnace. Combustion air is supplied from outside. In this case, in order to prevent the destruction of the flow of pulverized coal and avoid the deposition of pulverized coal or the failure of stabilization of the burner flame, the ignition nozzle and the flame detector are installed in the air supply unit for combustion from the outside, and not at the outlet of the pulverized coal.

If a flame detector or an ignition nozzle is installed in the combustion air supply unit, as in known technical solutions, then a situation arises that the installation location can affect the flame detection by the flame detector or the stability of ignition and flame i stabilization in the starting burner using an ignition nozzle.

In addition, the location of the flame detector in the path of the tertiary air flow in the pulverized coal burner is also known (see the unexamined publication of the Japanese patent application

Her 4-268103).

Patent literature 1. О2008-038426А1 2. МО2009-041081А1 3. МО2009-125566А1 4. Japanese publication of patent application Mo. Her number 4-268103, which did not pass the examination.

The problem solved with the help of the invention

In the patent literature 1) the known state of the art in relation to the invention of this application is disclosed, which is a burner in which the shape of the outlet opening of the cross-section of the fuel nozzle is rectangular, having a part of a long diameter and a part of a short diameter, elliptical or, in fact, elliptical, which has a long diameter section and a short diameter section.

Such a burner, by shortening the distance from the burned zone on the surface of the liquid fuel jet to the central part of this jet, makes it possible to reduce the unburned zone, providing time for burning after ignition.

However, as a result of the research carried out by the applicant, it was found that, in a burner where the open shape of the fuel nozzle near the open part of the surface of the wall of the boiler furnace is "flat-shaped", ensuring the reduction of the distance from the outer peripheral side, which is the source of ignition of the liquid fuel jet , toward the center part side, and the formation of a flame having a flat shape similar to the shape of the fuel nozzle opening is difficult when the open shape of the fuel nozzle is formed flat.

The reason for this, in the case of a solid fuel burner, can be considered to be that the inertial force of the fuel particles is greater than that of gas or liquid, and the fuel particles are not necessarily uniformly distributed over the nozzle shape within a short distance of the nozzle, and the fuel is highly scattered in the direction width compared to a nozzle that has, for example, the same capacity and a perfectly round shape. In particular, in the low-load zone, where the burner power is reduced, as the fuel flow rate is reduced, this problem becomes noticeable. As a result of this, there is a possibility that the ignition condition is insufficient towards the periphery of the nozzle and a zone is formed that can lead to an increase in unburnt fuel.

This is because the liquid fuel jet must flow a short distance (length in the axial direction; for example, C m) in the fuel nozzle to form a "flat shape" at high speed, about 25 m/s near the connecting part of the cylindrical carrier pipeline.

That is, it was found that the solid fuel has a higher inertial force than the carrier liquid, a high concentration of fuel in the central part in the direction of greater width, where the fuel can flow more easily, and a lower concentration of fuel at both end parts in the direction of greater width, where fuel is difficult to flow. Therefore, the distribution of the fuel concentration in the flowing fuel jet in the direction of greater width in the cross-section of the opening of the outlet part of the fuel nozzle is ensured.

Although the stoichiometric fuel/oxygen ratio is extremely low in the portion of the fuel nozzle having a low fuel concentration and is extremely high in the portion having a high fuel concentration, the fuel concentration distribution may be essentially flattened toward the periphery of the nozzle, and the mixture of fuel gas (the fuel gas nozzle, which is mainly a secondary air nozzle) from the outer periphery into the liquid fuel, may be essentially uniform in the outer peripheral part of the fuel nozzle.

In addition, the patent literature (1| describes a design characterized by the fact that in the inlet part of the fuel nozzle there is a plate for distributing the fluid medium, which evenly distributes the fuel in the fuel nozzle. This plate restrains the change in fuel concentration in the direction of the short diameter by simply inducing the fluid fuel to collide and distribute, but the plate does not ensure the equalization of the fuel concentration in the direction of the long diameter. As a result, as shown in Fig. 18(c) and Fig. 18(a), the fuel concentration at the exit part of the fuel nozzle is distributed so that it is high in the central part in the direction of the long diameter and low at both ends.

In addition, the flow of fuel gas (air) that exits the jet from a solid fuel burner is highly dependent on the configuration of the burner, especially the shape of the fuel gas passage. In particular, a solid fuel burner, in which the cross-sectional shape of the solid fuel nozzle, which is orthogonal to the flow of liquid fuel, is flat, is prone to the generation of a drift current. When the drift current is generated in this way, there is a problem that the stability of the flame from the burner becomes unsatisfactory. Among other things, the characteristics of the flow in the outer peripheral part at the exit of the nozzle for solid fuel or near the flame stabilizer installed in this part is important.

It is important to uniformly distribute in the peripheral direction the jet of fuel gas that is injected from the outer peripheral part of the solid fuel nozzle and to concentrate the mixed fluid medium of fuel and carrier gas to a fuel concentration that is sufficient for the stability of ignition/burning in the zone close to the outer peripheral part of the nozzle outlet in the radial direction from the central axis of the fuel nozzle to the outer peripheral part or flame stabilizer (near the inner wall of the fuel nozzle).

Additionally, in the invention described in document |C), although a flame detector or ignition nozzle is installed in the fuel air supply unit on the outer periphery of the pulverized coal nozzle, the installation location in the circumferential direction is not indicated. The problem does not arise if the pulverized coal nozzle and the fuel air supply unit have concentric shapes, but there is a problem of difficult detection of a stable flame or ignition of the pilot burner from the ignitor nozzle if the exit shape of the pulverized coal supply nozzle is rectangular, elliptical, or essentially elliptical.

The object of the present invention is to create a solid fuel burner that can provide a fuel concentration that is sufficient for stable fuel ignition/burning and achieve a low MOx concentration in the exhaust gas combustion products by creating a uniform fuel concentration in the circumferential direction at the exit of the fuel nozzle.

Means for solving the problem

The problem of this invention can be solved using the following means.

The invention, according to the first aspect, provides a solid fuel burner, containing: a fuel nozzle (8), which is open from the surface (18) of the furnace wall, and has a passage (2) for solid fuel, connected to a cylindrical fuel carrier pipeline (22), through which a mixture of solid fuel and solid fuel carrier gas is supplied; and one or more nozzles (10, 15) for fuel gas, which communicate with the nozzle chamber (3) into which the fuel gas for solid fuel enters, and which are formed on the outer side of the peripheral wall of the fuel nozzle (8), a solid fuel burner characterized by having in the fuel injector (8): a diffuser (7), which has a narrowed part that reduces the cross-section of the passage (2) for solid fuel in the fuel injector (8); and the fuel concentrator (b), which deflects the flow in the nozzle outwards on the outlet side of the diffuser (7), and the fuel nozzle (8) is designed in such a way that (a) the shape of its opening near the open part (32) on the surface (18) of the furnace wall boiler has a flat shape, (b) its cross-sectional shape, which is orthogonal to the central axis (C) of the nozzle, on the outer peripheral wall of the fuel nozzle (8) is rounded in cross-section to the narrowed part of the diffuser (7), (c) part , where the degree of flatness gradually increases, is provided between the narrowed part of the diffuser (7) and the open part (32) on the surface (18) of the boiler furnace wall, and (d) the open part (32) on the surface (18) of the boiler furnace wall is formed into a plane a form that has the maximum degree of flatness.

The invention, according to the second aspect, provides a burner, according to the first aspect, which is characterized by the fact that the flame stabilizer (9) is located on the outer periphery of the end of the outer peripheral wall of the fuel nozzle (8).

The invention, according to the third aspect, provides a burner according to the first or second aspect, which is characterized by the fact that the passage (4) for the fuel gas is provided in the nozzle (10) for the secondary fuel gas and is located on the innermost side of the plurality of nozzles (10, 15 ) for fuel gas, has the shape of a cross-section perpendicular to the central axis

(C) the outer peripheral wall of the nozzle (10) for the secondary fuel gas, which is formed into a flat shape at the outlet section of the passage (4) for the secondary fuel gas.

The invention, according to the fourth aspect, provides a burner according to the third aspect, which is characterized in that the passage (5) for the tertiary fuel gas in the nozzle (15) for the tertiary fuel gas, which is located on the outermost side of the plurality of nozzles (10, 15) for fuel gas, has the shape of a cross-section perpendicular to the central axis (C) of the outer peripheral wall of the nozzle (15) for tertiary fuel gas, which is formed in a round shape at the exit section of the passage (5) for tertiary fuel gas near the surface (18) of the furnace wall.

A flat shape can be a rectangular shape (Fig. 1 (a)), an elliptical shape (Fig. 1 (B)), a shape combining a semicircular shape and a rectangular shape (Fig. 1 (c)), or a wide polygon shape ( Fig. 1 (a)), that is, a flat shape that has a long side UM and a short side H.

In fig. 1 (a), some or all four corners may be rounded. In addition, in fig. 1 (4), some or all corner sections of a polygon can be rounded. Additionally, in each of the forms described above, the curvature of the rounded area is not limited to a fixed curvature.

In addition, the "degree of flatness" is defined as the ratio M/H of the long side of the MU and the short side of the H. Therefore, the gradual increase in the degree of flatness means that the ratio

The M/H of the cross-section perpendicular to the central axis (C) of the fuel injector (8) gradually increases, and the maximally flat shape means the shape of the part with the highest M/H ratio in the fuel injector (8).

In practice, the MU/N ratio in the open part (32) of the fuel injector furnace (8) is set in the range from 1.5 to 2.5. When the UM/H ratio is less than about 1.5, high efficient combustion with low MOx cannot be achieved in accordance with the present invention because the increase in the degree (ratio) of planarity is insufficient and the flame spread in the direction of greater width in the furnace (11) is small. When the relationship

M/H higher than about 2.5, the size of the long side M at the outlet of the fuel nozzle (8) will be too large, and the installation of the fuel nozzle (8) in the burner hole is difficult.

The invention, according to the fifth aspect, provides a burner according to the third or fourth aspect, which is characterized in that the passage (4) for the secondary fuel gas has a configuration, in

From which the cross-sectional area of the passage gradually decreases from the inlet area (17) for fuel gas in the direction of the open part (32) on the surface (18) of the furnace wall.

The invention, according to the sixth aspect, provides a burner according to the third or fourth aspect, which is characterized by the fact that the gas inflow direction of the inlet section (17) for fuel gas, the passage (4) for secondary fuel gas is set in the vertical direction to the surface (18) of the furnace wall, and in the inlet area (17) for fuel gas there is a flat plate (17a, 175) that has a number of holes (17aa, 17bra).

The invention, according to the seventh aspect, provides a burner according to the fifth or sixth aspect, which is characterized in that the openings (17aa, 17Bra) of the flat plates (17a, 175) located in the inlet area (17) for the fuel gas of the passage (4) for secondary fuel gas, located in such a way that the fuel gas flow rate in the passage (4) for the secondary fuel gas becomes constant in the peripheral direction of the passage (4).

The invention, according to the eighth aspect, provides a burner according to the fifth or sixth aspect, which is characterized by the fact that the ratio of the relative opening of the holes (17aa, 17ra) of the flat plates (17a, 175) to the cross-sectional area of the inlet section (17) for the fuel gas passage (4) for secondary fuel gas is 0.05-0.30.

The invention, according to the ninth aspect, provides a burner according to the fifth or sixth aspect, which is characterized by the fact that the burner according to item 5 or item 6, which differs in that the coefficient of reduction of the cross-sectional area of the passage (4) for the secondary fuel of gas from the inlet section (17) for fuel gas passage (4) for secondary fuel gas to the outlet section is 30-80 9.

The invention, according to the tenth aspect, provides a burner according to the first aspect, which is characterized in that the flame detector (40) and the control burner (41) are located at both ends on the long side, when the shape of the exit hole of the fuel injector (8) releasing solid fuel and solid fuel carrier gas, is rectangular, at the foci of the ellipse, when the shape of the outlet of the fuel injector (8) is elliptical, and at both ends of the linear section, when the shape of the outlet of the fuel injector (8) is essentially elliptical and has linear sections and circular sections.

The effect of the invention

According to the first aspect of the invention, since the liquid fuel is supplied to the furnace (11) while maintaining a uniform distribution of the fuel concentration in the liquid fuel near the inner wall of the fuel nozzle (8), the stoichiometric ratio of oxygen near the inner peripheral wall of the fuel nozzle (8) becomes sufficient throughout the entire internal periphery, and high combustion efficiency of fuel with a low MOX concentration can be achieved.

According to the second aspect, in addition to the effect of the invention described according to the first aspect, the installation of the stabilizer (9) in the flame facilitates the ignition of the fuel near the fuel nozzle (8) and the combustion of the fuel, which has a low MOx concentration, which further contributes to high efficiency.

According to the third aspect, in addition to the effect of the invention described according to the first or second aspects, when the cross-sectional shape orthogonal to the central axis (C) of the outer peripheral wall of the secondary fuel gas nozzle (10) is formed in a flat shape at the exit of the nozzle so that that the gap between the flame stabilizer (9) and the nozzle (10) for the secondary fuel gas to which the secondary fuel gas is supplied is uniformly formed along the entire periphery, then the secondary fuel gas can be uniformly supplied with a uniform distribution of the fuel concentration formed near the inner peripheral wall of the fuel injector (8). That is, because the proportion of local fuel/fuel gas flow of the fuel in the high concentration zone near the inner peripheral wall of the fuel injector (8) and the secondary fuel gas on the outer side surrounding this zone can be uniform throughout the peripheral zone of the outlet section of the fuel injector (8 ), then optimal combustion can be obtained in the entire peripheral zone.

According to the fourth aspect, in addition to the effect of the invention described according to the third aspect, since the nozzle (15) for the tertiary fuel gas has a circular shape and the passages (5) for the tertiary fuel gas are arranged vertically, one above the other along the long side Mu of the fuel injector (8 ), which has a flat shape, the mixing of the tertiary fuel gas and the fuel is impaired compared to the case where the nozzle (15) for the tertiary fuel gas has the same flat shape as the fuel injector (8) and the nozzle (10) for the secondary fuel gas, and the region of excess fuel (reduction region) in the central part of the burner increases, facilitating low MOX combustion.

In addition, when the shape at the exit of the nozzle (15) of the tertiary fuel gas on the outer periphery is round, then it can be easily applied to the new burner and at

From the reconstruction of the existing burner, which has a round open part.

According to the fifth aspect, in addition to the effect described according to the third or fourth aspect of the invention, when the cross-sectional area of the passage (4) is gradually reduced from the inlet section (17) of the secondary air passage (4) towards the exit part, which is the jet port leading to the furnace (11), the flow rate successively becomes the same towards the periphery towards the outlet section of the passage (4) for secondary air.

According to the sixth aspect, in addition to the effect described according to the third or fourth aspect of the invention, since the inlet section (17) of the passage (4) for the secondary air is provided in a direction vertical to the wall of the furnace (18), and the flat plates (17a) are located there , 175), having a set of holes (1 7аа, 1 7бБа), then the amount of secondary air injected into the furnace (11) can be the same in the peripheral direction in the outlet area (4) for secondary air, which can contribute to the stabilization of the flame and improving combustibility, which leads to a decrease in CO or unburned fuel. In particular, in the burner (31), which can change the speed of the tertiary air in the passage (5) for the tertiary air at the farthest peripheral part depending on the upper and lower sides of the furnace (11), the amount of injected secondary air in the outlet part of the passage (4) for secondary air can be aligned in the peripheral direction and this alignment is important from the point of view of increasing combustion stability.

According to the seventh aspect, in addition to the effect described according to the sixth aspect, since the holes (17aa, 17Bra) of the flat plates (17a, 17B) located in the inlet section (17) of the secondary fuel gas passage (4) are arranged as follows so that the flow rate of the secondary fuel gas becomes the same in the passage (4) along the peripheral direction, the amount of injected secondary air in the outlet passage (4) can be the same in the peripheral direction, thereby increasing the combustion stability.

According to the eighth aspect, in addition to the effect described according to the fifth or sixth aspect, the ratio of the maximum speed and the minimum speed of the secondary fuel gas flow is 2 or less, which is achieved by setting the relative opening of the holes (17aa, 17Bra) of the flat plates (17a , 175) in relation to the cross-section of the inlet section (17) of the passage (4) for secondary fuel gas at the level of 0.05-0.30. Because the flow rate in the outlet section of the passage (4) for the secondary fuel gas in the peripheral direction can be the same and the drift current of the secondary fuel gas flow is no longer present.

According to the ninth aspect, in addition to the effect described according to the fifth or sixth aspect, since the reduction factor (its definition will be described later) of the cross-sectional area of the passage (4) for the secondary fuel gas is set to 30-80 Fo from the inlet section (17) of the passage (4) for the secondary fuel gas in the direction of the outlet section, the ratio of the maximum speed and the minimum flow speed does not change much, and therefore the flow rate in the outlet section of the passage (4) for the secondary fuel gas in the peripheral direction can be is the same and the drift current of the secondary fuel gas flow is no longer present.

According to the tenth aspect, in addition to the effect described according to the first aspect, since the flame of the pilot burner (41) can be guaranteed to be detected during maintenance of the solid fuel burner, the malfunction caused by starting and other operations in the fuel unit or the like , which has solid fuel burners, can be eliminated.

Brief description of the drawings

Fig. 1 is a view showing various cross-sectional shapes of an open portion of a pulverized coal nozzle according to an embodiment of the present invention.

Fig. 2 shows a cross-sectional side view (Fig. 2 (a)) of a pulverized coal burner, a front view (Fig. 2 (p)) looking from the side of the firebox, a cross-sectional view taken along the line A-A (Fig. 2 (c)) , and a horizontal cross-sectional view (Fig. 2 (a)) of a pulverized coal burner according to an embodiment of the present invention.

Fig. C shows a view (Fig. C (a) side in section) explaining the state of flow of the main current in the pulverized coal nozzle of a pulverized coal burner, a front view (Fig. C (5)), when viewed from the side of the furnace, a horizontal cross-sectional view (Fig. C (c)), and a view (Fig. C (4)) showing the result of measuring the concentration of pulverized coal in the output part of the pulverized coal nozzle in Fig. 2.

Fi. 4 is a view showing the relationship between the fuel concentration/average fuel concentration ratio and the flammability near the flame stabilizer of a conventional pulverized coal burner.

From Fig. 5 shows a plan view (Fig. 5 (a)) of a flat plate provided at the inlet section of the secondary air passage of a pulverized coal burner according to an embodiment of the present invention and a perspective view (Fig. 5 (b) ) of half of a flat plate.

Fig. b shows another variant of the flat plate provided in the secondary air inlet of the pulverized coal burner according to the embodiment of the present invention, where fig. b (a) is a plan view of a flat plate in the intake area for secondary air, and fig. 6 (p) is a perspective view of half of a flat plate.

Fig. 7 shows a graph of the ratio of the actual measured values of the relative opening of the inlet section for the secondary air of the pulverized coal burner and the distribution of the flow rate at the outlet section of the passage for the secondary air according to an embodiment of the present invention.

Fig. 8 shows the type of relationship between the coefficient of reduction of the cross-sectional area of the outlet section in relation to the cross-sectional area of the intake section for the secondary air of the pulverized coal burner and the ratio of the maximum and minimum flow velocities in the passage for the secondary air according to the embodiment of this invention.

Fig. 9 is a schematic view of the velocity distribution in the inlet section when the flat plate is not installed in the inlet section of the secondary air passage of the pulverized coal burner (Fig. 9 (a)) and when the flat plate is installed (Fig. 9 (b)), according to the variant implementation of this invention.

Fig. 10 is a sectional side view of a pulverized coal burner according to an embodiment of the present invention;

Fig. 11 is a cross-sectional view along the line B-B in fig. 10.

Fig. 12 shows a modification (cross-sectional view along line B-B in Fig. 10) of a pulverized coal burner according to an embodiment of the present invention.

Fi. 13 shows a modification (cross-sectional view along line B-B in Fig. 10) of a pulverized coal burner according to an embodiment of the present invention.

Fig. 14 shows a modification (cross-sectional view along line B-B in Fig. 10) of a pulverized coal burner according to an embodiment of the present invention.

Fig. 15 shows (Fig. 15 (a), Fig. 15 (b)) examples of arrangement of pulverized coal burners on 60 walls of the furnace according to the embodiment of this invention.

Fig. 16 shows a side view in section (Fig. 16 (a)) of the entire furnace in which the burners in Fig. 15 (a), and a cross-sectional view (Fig. 16 (B)) along line A-A in Fig. 16 (a).

Fig. 17 shows a sectional side view (Fig. 17 (a)) of the entire furnace, in which the burners are located, each of which has a pulverized coal nozzle, the cross-section of which is circular, instead of flat in known designs, and a cross-sectional view (Fig. 17 (B)) along the line B-B in fig. 17 (a).

Fig. 18 shows a horizontal cross-sectional view (Fig. 18 (a)) of a nozzle of a pulverized coal burner according to the prior art, a cross-sectional view (Fig. 18 (B)) along AA, a view (Fig. 18 (c)) showing the concentration distribution of fuel in the fuel nozzle in fig. 18 (a) in the direction of greater width, as a relative value when the average concentration is 1.0, and a view (Fig. 18 (4)) showing the distribution of fuel concentration in the cross section of the outlet open part of the pulverized nozzle, as a relative value when the average concentration is 1.0.

The best option (options) for the implementation of the invention

Next, an embodiment of the invention will be described with reference to the drawings.

In fig. 2 shows the best embodiment of the burner according to the invention.

First, the design of the solid fuel burner 31 (which may be referred to as the pulverized coal burner 31) will be explained. The starter burner 1 (Fig. 2), which uses oil or the like as fuel, is installed in the center, passage 2 for solid fuel (pulverized coal or the like), the movement of which is carried out with the help of a carrier gas (air or similar) located around this burner. The fuel gas (air) is divided into two streams in the blow chamber C to fill passage 4 for secondary fuel gas (which may be referred to hereafter as secondary air) and passage 5 for tertiary fuel gas (which may be referred to hereafter as tertiary air), which are located around passage 2 . The diffuser 7, in which the passage narrows and then expands, and the fuel concentrator 6 are located in the passage 2 for a mixed fluid medium of solid fuel and carrier gas, and the flame stabilizer 9 is installed on the outer periphery of the output part of the fuel nozzle 8 (which hereinafter referred to as a pulverized coal nozzle 8).

In fig. 2 (5) shows the front view of the pulverized coal burner, viewed from the side of the furnace 11. The flame stabilizer 9 has an annular shape on the end part of the pulverized coal nozzle

From 8, to form a circulation flow on the side to the wall of the flame stabilizer 9 and increase the flammability and the effect of flame stabilization. In fig. 2 (B) shows an example of the use of the flame stabilizer 9, which has protrusions similar to shark teeth formed on the side of the pulverized coal nozzle 8.

In addition, the shapes of the pulverized coal nozzle 8 and the secondary air nozzle 10 in this pulverized coal burner 31 are flat when viewed from the side of the furnace 11 (see Fig. 16). The secondary air enters passage 4 for secondary air from the inlet section 17 for secondary air, and the fuel secondary air is supplied to the periphery of the pulverized coal nozzle 8 from the exit towards the firebox 11 of the boiler.

A set of opening elements 13, the area of which openings can be adjusted, is in the inlet part 12 for tertiary air. In addition, the nozzle 15 for the tertiary air in the outlet part from the side of the furnace 11 extends toward the outside and the tertiary air is fed toward the outside into the furnace 11.

Next, the design of the pulverized coal nozzle 8 and the effect that this design gives will be described.

The mixed fluid medium 21 of pulverized coal and carrier gas is supplied to the inlet part 23 of the burner through the pipeline 22 for fuel. Passage 2 for a mixed fluid medium, namely, for pulverized coal and carrier gas downstream of the inlet part 23 of the burner is narrowed with the help of a diffuser 7, and then widens. The expansion (NO) of the diffuser 7 in the vertical direction occurs in a range smaller than the inner diameter (01) of the pulverized coal nozzle 8 of the inlet part 23 of the burner, and then the upper and lower walls of the pulverized coal nozzle 8, which constitute the passage 2 for the mixed fluid medium, extend in a straight direction to furnace 11 (Fig. 16). The stretching of the passage 2 for the mixed fluid medium in the horizontal direction near the diffuser 7 continues to the position near the exit of the nozzle 8. The cross-sectional shape of the nozzle 8 changes from a round shape to a flat shape during the stretching process, and the degree (ratio) of flatness gradually increases as the stretching in the horizontal direction . The linear part of the pulverized coal nozzle 8 extending horizontally from the extended part is provided for the placement of the flame stabilizer 9, and the extension of the pulverized coal nozzle 8 in the horizontal direction may continue to the portion of the flame stabilizer 9 depending on the placement method of the flame stabilizer 9. The degree (ratio) of flatness is maximum in the output part of the pulverized coal nozzle 8, i.e., in the zone of the flame stabilizer 9.

In fig. C shows the flow of the main flow of pulverized coal in the pulverized coal nozzle 8 from the inlet part 23 of the burner to the outlet of the pulverized coal nozzle 8. Fig. (a) shows the view of the longitudinal section of the pulverized coal nozzle 8, and Fig. C (B) shows a horizontal cross-sectional view of the pulverized coal nozzle 8. In the flow on the side of the diffuser 7 downstream in the nozzle 8, part 25, which is shaded by dots in fig. C, schematically shows the zone in which pulverized coal is concentrated.

The mixed fluid medium of pulverized coal and carrier gas becomes a compressed flow in the direction of the central axis C when the diffuser 7 narrows and forms an annular flow along the support tube 24 of the fuel concentrator. When this flow reaches the fuel concentrator 6, it turns into an external flow with the help of the inclined part of the front surface of the fuel concentrator 6.

It should be noted that, as an example, the fuel concentrator 6 has: an inclined part with a conical front surface, the axial cross-sectional area of which increases with the support tube 24 as a central axis, a parallel cylindrical part having essentially the same axial cross-sectional area, provided on the outlet side of the diffuser, and a rear inclined part with a conical surface, the axial cross-sectional area of which decreases, provided further on the outlet side.

The passage in the pulverized coal nozzle 8, in which the rear inclined part is located, can be called an expanded part of the passage, since its cross-sectional area increases significantly.

Even in the case when the intensity distribution of the pulverized coal flow in the nozzle 8 is not the same in the inlet part 23 of the burner, the fuel is temporarily collected in the direction of the central axis in the narrowed part of the diffuser 7, and then the distribution of the intensity of the fuel flow in the peripheral direction is equalized in the process of expansion with the help of a concentrator 6 fuel. In the flow of pulverized coal expanded by the fuel concentrator 6, the flow of the component in the perpendicular direction immediately collides with the horizontal sections of the upper and lower inner peripheral walls of the pulverized coal nozzle 8 (Fig. C (a)) and changes into

From the direct direction. The flow of the horizontal direction component has an outward velocity component, which is provided by the inclined part of the front surface of the fuel concentrator 6, which is present until it reaches the outlet of the pulverized coal nozzle 8, and the main flow of pulverized coal continuously expands even after entering the furnace 11 on the downstream side of the outlet pulverized coal nozzle 8.

The combination of the configuration of the pulverized coal nozzle 8, the diffuser 7 and the fuel concentrator 6 provides an increase in the degree (ratio) of the planarity of the pulverized coal flow form even after passing through the nozzle 8 and a uniform distribution of the fuel concentration near the inner peripheral wall of the pulverized coal nozzle 8 around the flame stabilizer 9.

In fig. (4) shows the result of measuring the concentration of pulverized coal in the output part of the pulverized coal nozzle 8 in Fig. 2, and also provides an example of measuring the fuel concentration distribution in the outlet part of the pulverized coal nozzle 8 according to this embodiment.

The fuel concentration/average fuel concentration ratio in the central part of the pulverized nozzle 8 is only 0 or less, the fuel concentration increases as it approaches the outer peripheral part, and the fuel concentration at the outer peripheral part is about 1.5 times the average concentration. In addition, the concentration distribution in the peripheral direction of the nozzle 8 is the same, and the deviation of the fuel concentration in the outermost peripheral part of the pulverized nozzle 8, which is closest to the flame stabilizer 9 and plays an important role for, for example, ignition, is reduced to approximately 50.1, referring to the fuel concentration/average fuel concentration ratio. As described above, since the fuel concentration is obtained, which is the same in the peripheral direction of the pulverized coal nozzle 8, a stable ignition ratio/flame stability is ensured.

The concentration distribution in the outlet part of the fuel nozzle 42 (Fig. 18) was investigated, which corresponds to the prior art, which cannot be applied to the combination of the aforementioned pulverized coal nozzle 8, the diffuser 7 and the fuel concentrator 6. It should be noted that the fuel nozzle 42 in Fig. 18 has the form of a burner described in patent literature 1. In fig. 18 (a) shows a horizontal cross-section of the pulverized coal nozzle 42, and in fig. 18 (p) shows a cross-sectional view along line A-A in fig. 18 (a).

In fig. 18 (c) shows a graph of the fuel concentration distribution in the transverse direction along the width of the pulverized coal nozzle 42, which corresponds to fig. 18 (a), in the form of a relative value when the average concentration is 1.0, and in fig. 18 (4) shows the fuel concentration distribution (area) in the cross-section at the exit from the open part of the pulverized coal nozzle 42 in the form of a relative value when the average concentration is 1.0.

As described above, in the comparative example shown in fig. 18, the concentration in the central part along the horizontal direction (nozzle width direction) is high, the fuel concentration is low, towards both end sections, and the fuel concentration decreases to about 0.5 of the average value at both end sections, which are farthest from central area. This is because the air flow spreads in the horizontal direction, copying the shape of the nozzle, and the pulverized coal in the form of solid particles is concentrated in the central part without diffusing in the horizontal direction and other directions, and without spreading along the shape of the nozzle. Thus, the form of a horizontally diffusing jet, similar to the fuel jet according to the present invention, cannot be obtained (see Fig. 3(c)).

In this case, even if such a fuel concentrator is installed as shown in patent literature drawings 1, which concentrates fuel in the vertical direction of the pulverized coal nozzle 42 over the entire area of the pulverized coal nozzle 42 along the width, the fuel is concentrated on the upper side and the lower side of the open part of the nozzle 42 in vertical direction, but the concentration of pulverized coal is still high in the central part along the horizontal direction (cross-width direction) of the nozzle 42. The concentration of pulverized coal decreases as it approaches both sides of the end portion, and the concentration of pulverized coal at both end portions, which are farthest from of the central part is still low.

The relationship between the fuel concentration in the outermost peripheral part of the pulverized nozzle 8 and ignition/flame stability improves as the fuel concentration increases. Thus, in the case of the form of pulverized coal nozzle shown in fig. 18, in the outermost peripheral part of the pulverized nozzle 42, the ignition/flame stability is maintained in the central part where the fuel concentration is 1.3 or more, but the flammability decreases in both end regions where the fuel concentration/average fuel concentration is 1, 0 or less.

On the other hand, in the case of the pulverized nozzle shape according to the present invention, the fuel concentration in the outermost peripheral part of the pulverized nozzle 8 is the same and is approximately 1.5 times the average concentration, and the flammability/flame stability is excellent throughout the periphery of the pulverized nozzle 8.

The advantage is that the fuel concentration in the most distant peripheral part of the pulverized nozzle exceeds the average concentration and there is a uniform concentration of fuel in the peripheral direction. The first advantage is that solid fuel combustion is facilitated by maintaining the flammability/flame stability ratio within the limits described above. Combustibility promotion allows for highly efficient combustion.

The second advantage is that the effect of low MOx combustion occurs while improving the flammability/flame stability ratio. In the case of a solid fuel burner according to this invention, the flame formed at the exit from the pulverized coal nozzle does not immediately mix with the external peripheral air, for example, tertiary air.

A circulation area is formed between the fuel jet and the outer peripheral air jet, and a phenomenon occurs where the gas in the furnace flows back to the part near the burner.

Since the gaseous products of combustion remain in this area, the oxygen concentration is low, and

The MOH formed by the flame formed at the exit of the pulverized coal nozzle is reduced in this area. This state is called the recovery zone. Since the accelerated combustion at the exit from the pulverized coal nozzle allows to sufficiently ensure the time of stay in the recovery zone, the concentration of MOx in the gaseous products of combustion can be reduced.

In the case of the form of pulverized coal nozzle shown in fig. 18, the flammability at the exit of the nozzle 40 is not the same in the peripheral direction, the flammability/flame stability ratio becomes insufficient at both end sections, the residence time in the recovery zone cannot be guaranteed, and the MOx concentration increases. On the other hand, in the case of the form of the pulverized coal nozzle according to the present invention, since the fuel concentration at the outermost periphery of the nozzle 8 is the same in the peripheral direction and is higher than the average concentration, the flammability/flame stability ratio is excellent, the residence time in recovery zone is sufficiently assured and therefore low MOX combustion can be achieved.

Next, the secondary air nozzle 10 in the variant shown in Fig. 2, according to this invention. Secondary air nozzle 10, shown in fig. 2, has a flat shape and has a gap relative to the flame stabilizer 9 that is the same along the entire periphery (see Fig. 2 (c)).

It should be noted that in this embodiment, the inner surface of the wall of the secondary air nozzle 10 corresponds to the outer peripheral wall of the pulverized coal nozzle 8 (fuel nozzle).

As shown in fig. 2 (c), the gap between the secondary air nozzle 10 and the flame stabilizer 9 is essentially the same around the entire periphery. Thus, the secondary air can be uniformly supplied in the peripheral direction, respectively, providing a uniform distribution of the fuel concentration near the inner peripheral wall of the pulverized nozzle 8. That is, since the local fuel ratio/the ratio of the flow rate of gaseous products of fuel combustion in the zone with a high fuel concentration near the inner peripheral wall of the wall of the pulverized coal nozzle 8, and the secondary air on the outer side surrounding the zone, can be the same throughout the peripheral zone of the outlet part of the pulverized coal nozzle 8, then optimal combustion can be obtained throughout the peripheral zone.

In the embodiment shown in fig. 2, the tertiary air nozzle 15 has a round shape at the outlet, and the tertiary air passage 5 is positioned so as to vertically install the pulverized coal nozzle 8 (see 2 (c)). As a result, the mixing of tertiary air and fuel is stimulated, and low-Mox combustion is facilitated.

In addition, when the shape at the outlet of the tertiary air nozzle 15 on the most distant periphery of the pulverized coal burner 31 is round, it facilitates its use not only as a new burner, but also for the modernization of existing burners having a round open part.

The water wall pipe which creates the furnace wall surface 18 must be designed to provide an open portion 32 of the surface 18 for the burner, but the importance of this design increases as the power of the burner 31 increases. If the exit shape of the tertiary air nozzle 15 at the outermost periphery is round, then to form the open part 32 for the burner, the curvature of the water wall pipe, which is performed by bending, can be relatively large, and the pipe will be smooth. That is, the water wall pipe can be easily manufactured, the stress concentration during bending can be reduced, and the resistance to the internal fluid flowing through the water wall pipe can be reduced.

Next will be a description of the structure that stabilizes the flame by homogenizing the flow of secondary air from the nozzle 10 for the secondary air of the passage 4 for the secondary air in the direction of the periphery.

Passage 4 for secondary air has such a configuration that the cross-sectional area of the passage decreases from the inlet area for secondary air (inlet area for secondary air) 17 in the direction of the outlet of secondary air on the side of the furnace.

First, consider the effect of the ratio of the cross-sectional area of the inlet section 17 of the secondary air and the cross-sectional area of the passage 4 for the secondary air near the outlet section on the flow velocity distribution in the outlet section of the passage 4 for the secondary air.

The relationship between the ratio of cross-sectional areas and the distribution of the flow rate in the outlet section of passage 4 for secondary air was estimated from experimental data using a fluidity testing apparatus collected by the authors of this invention. An apparatus having the same shape as the pulverized coal burner 31 with the outlet shape shown in fig. 1, and the outlet section of passage 4 for secondary air was equally divided into 16 parts in the peripheral direction. When changing the ratio of the cross-sectional area of the inlet section 17 and the cross-sectional area near the outlet section, the flow rate in each part was measured using an anemometer with a thermocouple. It should be noted that air, which has a normal temperature, was used as a fluid medium. As an indicator showing the homogenization of the flow rate, the ratio of the maximum flow rate and the minimum flow rate was taken and evaluated. If this ratio is 1, it means that the flow rate is homogenized.

In fig. 8 shows the coefficient of reduction of the cross-sectional area of the outlet section of the secondary air in relation to the cross-sectional area of the intake section 17 of the secondary air in order to estimate the ratio of the maximum flow rate and the minimum flow rate in passage 4 for the secondary air. Determination of the coefficient of reduction of the cross-sectional area on the abscissa axis in Fig. 8 will be described later. However, the flat plates 17a and 175 were not installed in the intake section 17 for secondary air.

In addition, the cross-sectional area of the outlet part of the intake section 17 for secondary air is the cross-sectional area in the state when the flame stabilizer 9 is not provided, that is, immediately before the passage for secondary air, it is reduced by the flame stabilizer 9.

Reduction of the cross-sectional area - (1 - cross-sectional area of the exhaust section/cross-sectional area of the intake section) x 100 (95).

As a result, the ratio of the maximum flow rate to the minimum flow rate is greatly reduced until the reduction ratio reaches about 40 95, and then the ratio gradually decreases to about 1. When the reduction ratio is 30 95 or more, the ratio of the maximum flow rate to the minimum flow rate is 2 or less. However, when the reduction ratio of the cross-sectional area is set too high, the amount of inlet gas decreases as the ratio of the diaphragms, which will be described below, and therefore it is desirable to set the reduction ratio of the cross-sectional area of the passage 4 for the secondary air at the level of 30-80 Ob.

In fig. 5 shows an embodiment of the shape of the flat plate 17a provided in the inlet section 17 of the passage 4 for secondary air. In fig. 5 (a) shows a top view of the flat plate 17a, and in fig. 5 (p) shows a perspective view of half of the flat plate 17a.

In the variant shown in fig. 5(a), there are many round holes 17aa symmetrically arranged vertically and horizontally in the flat plate 17a having a rounded rectangular shape. It should be noted that the inner circular hole is the area of contact with the pulverized coal nozzle 8. In addition, this flat plate 17a has a horizontally separated into two halves structure, as shown in fig. 5 (b) so that it can be easily installed. In this embodiment, the relative opening of the flat plate 17a provided in the secondary air inlet section 17 is approximately 9 95.

In fig. 6 shows another version of the flat plate, which is placed in the inlet part 17 for secondary air. In fig. 6 (a) shows a plan view of the flat plate 17p for the inlet section 17, and in fig. b (b) a perspective view of half of the flat plate 17 is shown.

The relative opening of the flat plate 170 to the secondary air inlet portion 17 is approximately 11 95.

It should be noted that in the embodiments shown in fig. 5 and 6, the holes of the flat plates 17a and 175, provided in the open part of the intake section 17 for secondary air, have a round shape, see holes 17aa and 17ra, but the present invention is not limited to such shapes, and the holes may have polygonal shapes, for example, an elliptical shape or a square shape.

In addition, the flat plates 17a and 1765 are not limited to a rounded rectangular shape, and may have different shapes, for example, a round shape or an angular shape, depending on the configuration of the secondary air inlet section 17. However, to equalize the flow rate in the outlet section of passage 4 for secondary air in the transverse direction of the cross-section, it is desirable to arrange the holes of the flat plates 17a and 17p in the inlet section 17 for secondary air vertically and horizontally symmetrically.

In fig. 7 shows the result of studying the distribution of the flow rate in the outlet section of the passage 4 for secondary air depending on the relative opening of each of the flat plates 17a and 176p of this inlet section 17, based on the same fluidity testing as described above. The result shown in fig. 7, proves that the ratio of the maximum flow rate to the minimum flow rate in the outlet section of passage 4 for secondary air is minimum when the relative opening is about 0.10 and the ratio of the maximum flow rate to the minimum flow rate is 2 or less when the relative opening is 0.30 or less. However, when the relative opening is very small, the amount of gas input is greatly reduced, and therefore it is desirable to set the relative opening of the secondary air inlet section 17 at 0.05-0.30 to match the flow rate in the outlet section of the passage 4 for secondary air.

In fig. 9 shows a schematic view, when flat plates 17a and 17p having holes 17aa and 17ra shown in fig. 5 or fig. 6, there is no passage 4 for secondary air in the inlet area 17 (Fig. 9 (a)) and when the flat plates 17a and 1765 are located there (Fig. 9 (5)). The direction of the flow and the strength of the secondary air are represented by the direction and length of each arrow.

In the case where flat plates 17a and 1765 are not located, see fig. 9 (a), when the secondary air enters the inlet section 17 of the passage 4 for the secondary air, a drift current takes place, which depends on the direction of the gas flow in the nozzle chamber C (in the example shown in Fig. 9, the secondary air is supplied from the upper left side), and the distribution of flow velocities differs in the cross-section of the inlet section 17 for secondary air. This drift current or flow velocity distribution affects the flow velocity distribution in the secondary air outlet section. On the other hand, in the case when flat plates 17a and 1765 with holes

17aa and 17ra are located in the intake area 17 for secondary air, as shown in fig. 9 (b), the difference in the drift current or flow velocity distribution is eliminated by the resistance of the flat plates 17a and 176, and a rectilinear flow having essentially the same flow velocity, which is the air flow flowing into the inlet portion 17, takes place.

Next, a description will be given of the structure in which the flame detector (EO) 40 is located in the secondary air nozzle to detect the flame from the starting burner 1 or the flame of combustion of pulverized coal fuel at the outlet of the burner 31. In addition, a control burner 41 is provided , to reliably light pilot burner 1.

In fig. 10 shows a sectional side view of the pulverized coal burner 31 according to variant 10 of the implementation of this invention, and in fig. 11 shows a cross-sectional view along the B-B line in Fig. 10. It should be noted that fig. 10 is the same as a sectional side view of the pulverized coal burner 31 shown in FIG. 2, but some elements in the drawing are omitted.

The form of the exit of the pulverized coal nozzle 8 of the pulverized coal burner 31 in Fig. 10th in fig. 11 is rectangular having a short side portion and a long side portion, elliptical in shape, or essentially elliptical in shape, having a linear portion and a circular portion, its outer peripheral portion having an elliptical or substantially elliptical secondary air nozzle 10, and the shape of the tertiary air nozzle 15 on the outer periphery has the same concentric shape as the starting burner (starting burner) 1.

The partition 14, which divides the horizontally vertical cross-section of the burner in the center, is inserted into the nozzle 15 for tertiary air in such a way that the consumption of tertiary air, which is introduced into the upper and lower sides, could be changed.

That is, the partition 14 is located relative to the outer peripheral wall of the nozzle 10 for secondary air and the inner peripheral wall of the nozzle 15 for tertiary air, and the passage 5 for tertiary air is divided vertically into two parts by the partition 14. The partition 14 is also a partition that divides vertically, the dust chamber C is divided into two parts. Therefore, when the amount of tertiary air from the dust chamber 3, which is divided vertically into two passages 5 for tertiary air, is adjusted by the corresponding dampers Zba-3z0a, the amount of fuel air flowing through each passage can change and the flame emitted from the pulverized coal burner 31 can be rejected in

From the vertical direction in the furnace 11.

The flame detector 40 (ED) and the control burner 41 are located in the upper zone of the nozzle 10 for the secondary air of the pulverized coal nozzle 8. The flame detector 40 is designed to detect the flame from the starting burner 1 located in the central part of the burner 31, or dusty coal. The flame from the burner 31, located on the front and back surfaces 18 of the side wall of the furnace 11 of the boiler, is deflected upward due to buoyancy and updraft, and therefore, it is desirable to install the detector 40 on the upper side, above the horizontal line passing through the center of the burner.

In addition, since the flame detector 40 is also intended to detect the flame of the control burner 41, it is desirable to arrange the flame detector 40 and the control burner 41 in the same plane, and therefore, a similar arrangement of the control burner 41 on on the upper side, above the horizontal line passing through the center of the burner.

Since the pipe is inserted into each of the nozzles 10 and 15 for fuel air, the flame detector 40 or the control burner 41 obstruct the flow of external peripheral air depending on their location. Since the cross-sectional area of the jet opening of the secondary air nozzle 10 is increased at the outer periphery of the long-side portion of the pulverized coal nozzle 8, the secondary air flow has a higher velocity near the outer peripheral wall of the long-side portion than at the outer periphery of the short-side portion .

When the flame detector 40 or the control burner 41 is located on the outer peripheral wall of the short side section of the pulverized coal nozzle 8, the flow of fuel air is hindered, and therefore air does not flow on the outer peripheral wall of the short side section.

In this case, nothing cools the flame detector 40 or the control burner 41, and therefore there is a fear that the flame detector 40 or the control burner 41 will burn out as a result of radiant heat from the furnace 11. On the other hand, since the external the peripheral wall of the long-side portion of the pulverized coal nozzle 8 has a high-velocity air flow, the possibility of burnout is reduced, but in the case of, for example, the pilot burner 41, the pilot flame for the pilot burner 1 is blown out when the combustion air flow rate is high , and, therefore, it is undesirable to place such an element in a position where the amount of air for combustion is large.

To ensure ignition of the starter burner 1, it is desirable to place the control burner 41 in a position where the combustion air flow rate is low.

Although it is desirable to place the flame detector 40 in a position where the amount of air for combustion is large from the viewpoint of preventing burnout, a high fuel concentration zone is formed at each of both ends of the outlet when the shape of the outlet of the pulverized nozzle 8 is rectangular, elliptical, or , essentially elliptical, and therefore, the installation of the flame detector 40 in a zone with a high concentration of fuel leads to a high sensitivity of flame detection.

Therefore, it is desirable to place the flame detector 40 or control burner 41 in an area with a small amount of fuel air and a high concentration of fuel, as well as in an area where the probability of burnout can be reduced.

The embodiment shown in fig. 11 is given as an example where the shape at the exit of the pulverized nozzle 8 is essentially elliptical and has linear parts and circular parts, the outer peripheral wall of the linear part has a wide passage 4 for secondary air, and the outer periphery of each circular part has a narrow passage 4 for secondary air, and therefore it is desirable to place the flame detector 40 or control burner 41 at the contact point of the linear part and the circular part.

The embodiment shown in fig. 12 (cross-sectional view along line B-B in Fig. 10) corresponds to the case where the shape at the outlet of the pulverized coal nozzle 8 is rectangular, the passage 4 for secondary air on the side of the part with a long side is wide, and the passage 4 for secondary air on the sides of the chasm with the short side is narrow. Therefore, it is undesirable to install the flame detector 40 or the control burner 41 in the center of the part with the long side or the part with the short side of the mold at the outlet of the pulverized coal nozzle 8, but it is preferable to install such an element at each of both ends of the part with the long side.

The embodiment shown in fig. 13 (cross-sectional view along line B-B in Fig. 10) corresponds to the case when the shape at the exit from the pulverized coal nozzle 8 is elliptical, the outer periphery between the foci of the ellipse has a wide passage 4 for secondary air, and

The outer peripheral wall outside the foci of the ellipse has a narrow passage 4 for secondary air. Thus, in this case, it is desirable to place the flame detector 40 or the control burner 41 on the outer peripheral wall behind the foci of the ellipse of the pulverized coal nozzle 8.

It should be noted that, in fig. 11-13, the flame detector 40 is located on the upper left side, and the control burner 41 is located on the upper right side, when looking at the burner 31 from the firebox 11, but no problem arises even if their placement is reversed.

The embodiment shown in fig. 14 (cross-section along the B-B line in Fig. 10), corresponds to an example where the burner shown in Fig. 11 rotated by 90 degrees. That is, this is an example where the circular parts forming the outer peripheral wall of the exit from the pulverized nozzle 8 are located on the upper and lower sides, and the linear parts are located on the left and right sides. In this case, it is desirable to place the flame detector 40 or control burner 41 above the horizontal line, i.e. above the center of the burner

C1.

In fig. 15 (a) shows an example of the location of the burners 31 on the surface 18 of the furnace wall, according to one of the variants of the implementation of this invention. In this example, the burners 31 are arranged in three rows and four columns on the surface 18 of the furnace wall, and the direction of the larger width of the pulverized coal nozzle 8, which has a flat shape, is defined as horizontal for all the burners. In fig. 16 shows a view which schematically illustrates that the space in the furnace 11 can be effectively used when using the pulverized coal burners 31 shown in fig. 15 (a), in comparison with the use of burners from the known state of the art; in fig. 16 (a) shows a side view in section of the entire furnace 11, in which the burners 31 in fig. 15 (a), and in fig. 16 (b) shows a sectional view along line A-A in fig. 16 (a). In addition, in fig. 17 (fig. 17(a)) shows a side view in section of the entire furnace 11, where the burners having pulverized coal nozzles are located, each of which has a cross-sectional shape that is circular and not flat, and in fig. 17 (b) shows a cross-sectional view along line A-A and shows a prior art configuration.

As shown in fig. 16, when all the pulverized coal burners 31 are installed horizontally in the direction of the larger width of each pulverized coal nozzle 8 having a flat shape, the fuel jet is dispersed in the horizontal direction in the furnace 11, the space of the furnace 11 can be efficiently used, and the fuel can be burned with high efficiency and low level concentrations of MOX.

As shown in fig. 16 (a) and fig. 16 (b), when all the burners 31 are located on the surface 18 of the furnace wall horizontally, meaning the installation in the direction of the greater width of the pulverized coal nozzles 8, each of which has a flat shape, the flame spreads horizontally in the furnace 11, compared to the prior art (see Fig. 1), thereby reducing unused space in the furnace.

That is, according to this embodiment, the cross-sectional area through which the flame passes increases in the horizontal cross-section in the furnace 11, the time that the flame is in the furnace 11 increases, the fuel efficiency improves, and the concentration of MOx gas products combustion can be reduced.

As described above, in the case of the pulverized coal nozzle 42 from the prior art (see Fig. 18 (a) and Fig. 18 (b)), which does not correspond to the design according to the present invention, where there is a combination: pulverized coal nozzle 8, diffuser 7 and fuel concentrator 6, there is an unsatisfactory distribution of fuel concentration at both ends of the sections in the horizontal direction, as shown in fig. 18 (c) and fig. 18 (4). Therefore, it is difficult to spread the fuel outwardly beyond the expansion limit (the angle of inclination relative to the central axis) in the horizontal direction in the furnace, particularly in the direction of the width of the pulverized coal nozzle 42, and to spread the flame in the horizontal direction.

Compared to this, in the embodiment according to the present invention, the pulverized fuel is not only concentrated on the separation side (located around the flame stabilizer 9) of the pulverized coal nozzle 8 and the nozzle 10 for secondary air, that is, on the outer periphery of the nozzle, and ignition can be performed uniformly along the entire periphery of the open part of the pulverized coal nozzle 8, but also to ensure a good distribution of fuel (the value obtained by integrating the fuel in the up-down direction at a characteristic horizontal position) in the horizontal section of the pulverized coal nozzle 8 (when the burner 31 is viewed from the side of the upward direction -down) on both sides of the end section, and not in the immediate vicinity of the central part in the horizontal direction (the direction of the greater width of the nozzle).

Therefore, the fuel can be dispersed outwardly beyond the expansion limit (the angle of inclination relative to the central axis C) in the horizontal direction in the furnace, particularly in the direction of the width of the pulverized coal nozzle 8, and the flame can spread in the horizontal direction.

Therefore, if the power of one burner is increased and the distance between the burners 31 adjacent to each other in the furnace along the horizontal direction is increased, then the space of the furnace can be effectively used without increasing the zone where the flame does not form.

In fig. 15 (b) shows an example of the location of the burners 31 according to another embodiment of the present invention. In this version, the burners 31 are arranged in three rows and four columns on the surface 18 of the furnace wall, the burners 31, which are close to the side walls, where there is a problem of ash adhesion on the surface 18 of the furnace wall, are arranged in such a way that the direction of the greater width of each pulverized coal nozzle 8 is vertical, the other burners 31 are located in the direction of the greater width of the pulverized coal nozzle 8, which has a flat shape in the horizontal direction. In this case, combustion will occur with high efficiency and low MOx concentration, while simultaneously reducing the problem associated with ash adhesion. In this embodiment, where the burners 31 near the side walls are arranged so that the larger width direction of each of the pulverized coal nozzles 8 having a flat shape is vertical, the larger width direction of some of the pulverized coal nozzles 8 having a flat shape may be vertical relative to some of the burners 31 that are close to the side walls (for example, only the burners 31 on the uppermost tier), and the larger width direction of the other pulverized coal nozzles 8 having a flat shape may be horizontal with respect to the other burners 31.

It should be noted that in the example of the location of the burners 31 shown in fig. 15 (a) and fig. 15 (5), the larger width direction of each flat-shaped pulverized nozzle 8 is installed vertically or horizontally, but there may be an inclined arrangement if the larger width direction cannot be vertical or horizontal due to the influence of some other structures around each burner 31.

List of links 1 starter burner 2 passage for pulverized coal bo Z dust chamber

4 passage for secondary air passage for tertiary air 6 fuel concentrator 7 diffuser 5 8 pulverized coal nozzle 9 flame stabilizer secondary air nozzle 11 firebox 12 inlet part for tertiary air 10 13 opening elements, for tertiary air 14 partition partition nozzle for tertiary air 17 inlet area for secondary air 18 furnace wall surface 15 21 mixed fluid medium 22 fuel carrier pipeline 23 burner inlet 24 fuel concentrator support tube 28 burner flame 29 two-stage fuel gas supply port 31 burner for solid fuel (pulverized coal) 32 open part furnace (part for installing the burner) flame detector 41 control burner

Claims (10)

FORMULA OF THE INVENTION 1. A solid fuel burner containing: a fuel nozzle (8), opened from the surface (18) of the furnace wall, and having a passage (2) for solid fuel, connected to a cylindrical pipeline-carrier Zo (22) of fuel, for passing the flow mixtures of solid fuel and solid fuel carrier gas; and more than one nozzle (10, 15) for the fuel gas, which communicates with the nozzle chamber (3) into which the fuel gas for the solid fuel is introduced, and which are formed on the outside of the peripheral wall of the fuel nozzle (8), which is characterized by that the fuel injector (8) has: a venturi tube (7) having a narrowed part 35 which reduces the cross-section of the passage (2) for solid fuel in the fuel injector (8); and a fuel concentrator (b) for diverting the flow in the nozzle outward to the outlet side of the venturi tube (7), and the fuel nozzle (8) is designed so that (a) the shape of its opening near the open part (32) of the surface (18) of the wall of the boiler furnace is a flat 40 shape, (b) the shape of its cross-section, perpendicular to the geometric axis (C) of the nozzle, on the outer peripheral wall of the fuel nozzle (8) is rounded in cross-section close to the narrowed part of the Venturi tube (7), (c) contains a part, where the ratio of the sides M/H, the long side MU to the short side H, 45 gradually increases and includes the upper and lower walls that expand towards the surface (18) of the boiler furnace wall with the same distance between the upper and lower walls, made between the narrowed part venturi tube (7) and the open part (32) of the surface (18) of the boiler furnace wall, and (d) the open part (32) of the surface (18) of the boiler furnace wall is formed flat with a maximum 50 aspect ratio M/N. 2. The burner according to claim 1, which is characterized by the fact that it additionally has a flame stabilizer (9) located on the outer periphery of the end of the outer peripheral wall of the fuel injector (8). 3. Burner according to claim 1 or 2, which differs in that the passage (4) for the secondary fuel gas, 55 is provided in the nozzle (10) for the secondary fuel gas, which is located closest to more than one of the nozzles (10, 15) for fuel gas, has the shape of a cross-section perpendicular to the geometric axis (C) of the outer peripheral wall of the nozzle (10) for secondary fuel gas, and it is made flat at the exit section of the passage (4) for secondary fuel gas. 4. The burner according to claim 3, which is characterized in that the passage (5) for the tertiary fuel gas in the nozzle (15) for the tertiary fuel gas, located furthest from more than one of the nozzles (10, 15) for the fuel gas, has the shape of the section perpendicular to the geometric axis (C) of the outer peripheral wall of the nozzle (15) for tertiary fuel gas, and it is made of a rounded shape at the exit section of the passage (5) for tertiary fuel gas near the surface (18) of the furnace wall. 5. Burner according to claim 3 or 4, characterized in that the passage (4) for the secondary fuel gas has a configuration in which the cross-sectional area of the passage gradually decreases from the inlet section (17) for the fuel gas in the direction of the open part (32). on the surface (18) of the furnace wall. 6. The burner according to claim 5, which is characterized by the fact that the gas flow direction of the inlet section (17) of fuel gas for the passage (4) of secondary fuel gas is set in the direction vertical to the surface (18) of the furnace wall, and in the inlet section (17) for fuel gas there is a flat plate (17a, 17p), which has a number of holes (17aa, 17bra). 1. The burner according to claim 6, which is characterized by the fact that the holes (17aa, 17ra) of the flat plates (17a, 176) located in the inlet area (17) for the fuel gas of the passage (4) for the secondary fuel gas are located in such a way that the flow rate of the fuel gas in the passage (4) for the secondary fuel gas becomes constant in the circumferential direction of the passage (4). 8. Burner according to claim 6, which differs in that the ratio of the holes (17аа, 17ра) of the flat plates (17а, 17Б) to the cross-sectional area of the inlet area (17) for fuel gas, the passage (4) for secondary fuel gas is 0.05- 0.30. 9. Burner according to claim 5 or 6, which differs in that the coefficient of reduction of the cross-sectional area of the passage (4) for secondary fuel gas from the inlet section (17) for fuel gas of the passage (4) for secondary fuel gas to the outlet section is 30-80 About. 10. The burner according to claim 1, which is characterized in that it additionally has a flame detector (40) and a control burner (41), which are located at both ends on the long side, when the shape of the outlet of the fuel nozzle (8) that emits solid fuel and solid fuel carrier gas, is rectangular, and which are located at the foci of the ellipse, when the shape of the exit hole of the fuel injector (8) is elliptical, and which are located at both ends of the linear section, when the shape of the exit hole of the fuel injector (8) is essentially elliptical with linear and 3-round sections. U Sh y U , Uu r. 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