A burnout air supply characteristic adjustable burner

Abstract

The present invention discloses a burnout air supply characteristic adjustable burner, which includes an outer burnout air duct, an inner burnout air duct, a variable cross-section baffle, a gear and a long handle rack; the inner burnout air duct includes a shaft hole and an inner burnout air duct housing; the variable cross-section baffle includes a rotating shaft and a flat plate. The central axes of the outer burnout air duct and the inner burnout air duct are arranged collinearly, and the arrangement order from outside to inside is the outer burnout air duct and the inner burnout air duct in sequence. Both ends of each variable cross-section baffle are rotationally matched with each shaft hole on the inner burnout air duct, each gear is in interference fit with each variable cross-section baffle, and each rack is arranged on the side of the inner burnout air duct and meshes with each gear for transmission. During the variable load peak shaving process of a thermal power unit, by adjusting the arrangement mode of the variable cross-section baffle, the flow cross-sectional area, the aspect ratio of the cross-section and the rectangular cross-section distribution characteristics of the inner burnout air are changed, so that the burnout air jet can ensure a higher jet velocity and rigidity under different load conditions, and effectively improve the combustion characteristics of the furnace flame under low load.

Description

Technical Field

[0001] The present invention relates to the technical field of power plant peak shaving, and particularly to a burnout air supply characteristic adjustable burner. Background Art

[0002] Due to the strong randomness and intermittency of wind power and photovoltaic power generation, their large-scale grid connection has a negative impact on the safe and stable operation of the power grid. To improve the consumption capacity of renewable energy, thermal power units that undertake more than 70% of the national power generation must undertake the peak shaving task of the power grid and will gradually change from the main body of power supply to the main body of power supply and peak shaving.

[0003] At present, thermal power units with deep peak shaving capabilities will surely occupy a leading position in China's future power supply system. However, they will also face many problems during the wide load change process. For example, at low loads, the total air volume of the boiler decreases with the decrease of the total coal volume. To ensure that the burnout air with different flows still has a high flow rate and stiffness within the wide load change range and reduce the heat loss of incomplete combustion, a burnout air supply characteristic adjustable burner will become a hot demand in this field. Summary of the Invention

[0004] The main technical problem to be solved by the present invention is to provide a burnout air supply characteristic adjustable burner, which can make the burner applicable to the wide load conditions with the change of the flow rate and stiffness of the burnout air.

[0005] To solve the above technical problem, one technical solution adopted by the present invention is:

[0006] A burnout air supply characteristic adjustable burner, comprising an outer burnout air duct 1, an inner burnout air duct 2, a variable cross-section baffle a 3, a variable cross-section baffle b 4, a variable cross-section baffle c 5, a gear a 6, a gear b 7, a gear c 8, a long handle rack a 9, a long handle rack b 10, and a long handle rack c 11; the inner burnout air duct 2 includes a shaft hole a 201, a shaft hole b 202, a shaft hole c 203, a shaft hole d 204, a shaft hole e 205, a shaft hole f 206, and an inner burnout air duct housing g 207; the variable cross-section baffle a 3 includes a rotating shaft a 302 and a flat plate a 301, the variable cross-section baffle b 4 includes a rotating shaft b 402 and a flat plate b 401, and the variable cross-section baffle c 5 includes a rotating shaft c 502 and a flat plate c 501; the central axes of the outer burnout air duct 1 and the inner burnout air duct 2 are arranged collinearly, and the arrangement order from outside to inside is the outer burnout air duct 1 and the inner burnout air duct 2 in sequence. Both ends of each variable cross-section baffle are rotationally matched with each shaft hole on the inner burnout air duct 2, each gear is in interference fit with each variable cross-section baffle, and each rack is arranged on the side of the inner burnout air duct 2 and meshes with each gear for transmission.

[0007] The variable cross-section baffle a3 includes a rotating shaft a302 and a flat plate a301, the variable cross-section baffle b4 includes a rotating shaft b402 and a flat plate b401, and the variable cross-section baffle c5 includes a rotating shaft c502 and a flat plate c501; the rotating shaft a302 passes through the central through hole on the side of the flat plate a301, the rotating shaft b402 passes through the central through hole on the side of the flat plate b401, and the rotating shaft c502 passes through the central through hole on the side of the flat plate c501; each rotating shaft is a cylindrical metal rotating shaft, each flat plate is a cuboid flat plate, and there is an interference fit between each rotating shaft and each flat plate.

[0008] The internal combustion exhaust pipe 2 includes a shaft hole a201, a shaft hole b202, a shaft hole c203, a shaft hole d204, a shaft hole e205, a shaft hole f206 and an internal combustion exhaust pipe housing g207; the shaft hole a201 and the shaft hole d204 are respectively fitted with the upper and lower ends of the rotating shaft a302, the shaft hole b202 and the shaft hole e205 are respectively fitted with the upper and lower ends of the rotating shaft b402, and the shaft hole c203 and the shaft hole f206 are respectively fitted with the upper and lower ends of the rotating shaft c502; the internal combustion exhaust pipe housing g207 is a square-section pipe, each shaft hole is a circular hole, and there is a clearance fit with the rotating shaft.

[0009] The gear a6 is fitted with the part of the upper end of the rotating shaft a302 that extends out of the shaft hole a201 and outside the internal combustion exhaust pipe 2, the gear b7 is fitted with the part of the upper end of the rotating shaft b402 that extends out of the shaft hole b202 and outside the internal combustion exhaust pipe 2, and the gear c8 is fitted with the part of the upper end of the rotating shaft c502 that extends out of the shaft hole c203 and outside the internal combustion exhaust pipe 2; each gear is a circular spur gear and has an interference fit with each rotating shaft.

[0010] The long handle rack a9 meshes with the gear a6, the long handle rack b10 meshes with the gear b7, and the long handle rack c11 meshes with the gear c8; each rack is a cuboid rack and is arranged on the left side of the internal combustion exhaust pipe 2.

[0011] Under the adjustment of transmission mechanisms such as the long handle rack a9 and the gear a6, the variable cross-section baffle a3 can rotate 90° along the axis, under the adjustment of transmission mechanisms such as the long handle rack b10 and the gear b7, the variable cross-section baffle b4 can rotate 90° along the axis, and under the adjustment of transmission mechanisms such as the long handle rack c11 and the gear c8, the variable cross-section baffle c5 can rotate 90° along the axis; rotate the variable cross-section baffle a3, the variable cross-section baffle b4 and the variable cross-section baffle c5 respectively, so as to change the flow cross-sectional area, cross-sectional shape and cross-sectional distribution characteristics of the outlet of the internal combustion exhaust pipe 2.

[0012] The beneficial effects of the present invention are:

[0013] The present invention relates to a burnout air supply characteristic adjustable burner. Compared with a conventional burnout air burner, under different load conditions during the peak load regulation process of a thermal power unit, by adjusting the arrangement mode of the variable cross-section baffle at the nozzle of the internal burnout air duct, the flow cross-sectional area, the cross-section height-width ratio, and the rectangular cross-section distribution characteristics of the internal burnout air are changed, so as to effectively ensure the jet velocity of the internal burnout air and the combustion rigidity of the furnace flame at different loads, enable the burnout air to have a greater penetration depth, and be able to mix well with the flame, so as to facilitate the burnout of pulverized coal therein. Description of the Drawings

[0014] Figure 1 It is a three-dimensional view of a burnout air supply characteristic adjustable burner of the present invention;

[0015] Figure 2 It is a three-dimensional view of the external burnout air duct of a burnout air supply characteristic adjustable burner of the present invention;

[0016] Figure 3 It is a three-dimensional view of the internal burnout air duct of a burnout air supply characteristic adjustable burner of the present invention;

[0017] Figure 4 It is a three-dimensional view of the variable cross-section baffle of a burnout air supply characteristic adjustable burner of the present invention;

[0018] Figure 5 It is a three-dimensional view of the gear of a burnout air supply characteristic adjustable burner of the present invention;

[0019] Figure 6 It is a three-dimensional view of the long handle rack of a burnout air supply characteristic adjustable burner of the present invention;

[0020] Figure 7 It is a three-dimensional view of the internal burnout air variable cross-section and stiffness mechanism of a burnout air supply characteristic adjustable burner of the present invention;

[0021] Figure 8 It is a top view of a burnout air supply characteristic adjustable burner of the present invention during peak load regulation at 50% of the rated load of the unit;

[0022] Figure 9 It is a right view of a burnout air supply characteristic adjustable burner of the present invention during peak load regulation at 50% of the rated load of the unit;

[0023] Figure 10 It is a top view of a burnout air supply characteristic adjustable burner of the present invention during peak load regulation at 35% of the rated load of the unit;

[0024] Figure 11 It is a right view of a burnout air supply characteristic adjustable burner of the present invention during peak load regulation at 35% of the rated load of the unit;

[0025] Figure 12 This is a top view of an adjustable burnout air supply characteristic burner of the present invention during peak shaving at 20% of the rated load of the unit;

[0026] Figure 13 This is a right view of an adjustable burnout air supply characteristic burner of the present invention during peak shaving at 20% of the rated load of the unit. Specific embodiments

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined.

[0028] The present invention is an adjustable burnout air supply characteristic burner, including an outer burnout air duct 1, an inner burnout air duct 2, a variable cross-section baffle a3, a variable cross-section baffle b4, a variable cross-section baffle c5, a gear a6, a gear b7, a gear c8, a long handle rack a9, a long handle rack b10, and a long handle rack c11; the inner burnout air duct 2 includes a shaft hole a201, a shaft hole b202, a shaft hole c203, a shaft hole d204, a shaft hole e205, a shaft hole f206, and an inner burnout air duct housing g207; the variable cross-section baffle a3 includes a rotating shaft a302 and a flat plate a301, the variable cross-section baffle b4 includes a rotating shaft b402 and a flat plate b401, and the variable cross-section baffle c5 includes a rotating shaft c502 and a flat plate c501.

[0029] As a preferred embodiment of the present invention, in combination with Figure 1 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6It can be obtained that the axes of the external burnout air duct 1 and the internal burnout air duct 2 are collinearly arranged, and the internal burnout air duct 2 is nested inside the external burnout air duct 1. The flow space between the external burnout air duct 1 and the internal burnout air duct 2 is the external burnout air flow space, and the internal space of the internal burnout air duct 2 is the internal burnout air flow space. The lower end of the rotating shaft a302 of the variable cross-section baffle a3 has a clearance fit with the shaft hole d204 and completely fills the shaft hole; the upper end of the rotating shaft a302 has a clearance fit with the shaft hole a201, and the remaining protruding part has an interference fit with the gear a6; the long handle rack a9 is arranged on the left side surface of the internal burnout air duct and meshes with the gear a6. The lower end of the rotating shaft b402 of the variable cross-section baffle b4 has a clearance fit with the shaft hole e205 and completely fills the shaft hole; the upper end of the rotating shaft b402 has a clearance fit with the shaft hole b202, and the remaining protruding part has an interference fit with the gear b7; the long handle rack b10 is arranged on the left side surface of the internal burnout air duct and meshes with the gear b7. The lower end of the rotating shaft c502 of the variable cross-section baffle c5 has a clearance fit with the shaft hole f206 and completely fills the shaft hole; the upper end of the rotating shaft c502 has a clearance fit with the shaft hole c203, and the remaining protruding part has an interference fit with the gear c8; the long handle rack c11 is arranged on the left side surface of the internal burnout air duct and meshes with the gear c8.

[0030] As Figure 2 shown, the external burnout air duct 1 is successively a contracted circular cavity, a cylindrical circular cavity, and a diffused circular cavity from left to right. The left contracted circular cavity is the incoming air port of the external burnout air, and the right diffused circular cavity is the outlet where the external burnout air swirls into the furnace.

[0031] As Figure 3 shown, the internal burnout air duct 2 is a square prism hollow pipe, including a shaft hole a201, a shaft hole b202, a shaft hole c203, a shaft hole d204, a shaft hole e205, a shaft hole f206, and an internal burnout air duct housing g207. The left pipe orifice is the incoming air port of the internal burnout air. On the left wall surface of the right pipe orifice, circular shaft holes a201, a shaft hole b202 (at the vertical midpoint), and a shaft hole c203 of the same size are arranged at equal intervals. On the right wall surface of the right pipe orifice, circular shaft holes c204, a shaft hole d205 (at the vertical midpoint), and a shaft hole e206 of the same size are symmetrically arranged at equal intervals for fixing the rotating member, the variable cross-section baffle.

[0032] As Figure 4As shown in the figure, from left to right are variable cross-section baffle a3, variable cross-section baffle b4, and variable cross-section baffle c5. The variable cross-section baffle a3 includes a rotating shaft a302 and a flat plate a301, the variable cross-section baffle b4 includes a rotating shaft b402 and a flat plate b401, and the variable cross-section baffle c5 includes a rotating shaft c502 and a flat plate c501. The rotating shaft a302 passes through the central through hole on the side of the flat plate a301, the rotating shaft b402 passes through the central through hole on the side of the flat plate b401, and the rotating shaft c502 passes through the central through hole on the side of the flat plate c501. Each rotating shaft is a cylindrical metal rotating shaft and has the same shape. The end that penetrates the flat plate at the top is the upper end of the rotating shaft, and the end that penetrates the flat plate at the bottom is the lower end of the rotating shaft. Each flat plate is a cuboid flat plate with the same shape and a central through hole. The forward bottom edge of the flat plate is the length of the variable cross-section baffle, the lateral bottom edge is the width of the variable cross-section baffle, and the vertical edge is the height of the variable cross-section baffle. There is an interference fit between each rotating shaft and each flat plate.

[0033] As Figure 5 shown, from left to right are gear a6, gear b7, and gear c8. Each gear is a spur circular gear with the same shape.

[0034] As Figure 6 shown, from bottom to top are long handle rack a9, long handle rack b10, and long handle rack c11. Each long handle rack is a rectangular straight rod of the same size, and there are fine teeth meshing with the teeth of each gear at the right end.

[0035] Through the deep peak shaving test of a 660MW thermal power unit in a certain power plant, it is found that when the load is 150MW, the coal quantity is about 75t / h, and the total air volume is about 750t / h; when the load is 198MW, the coal quantity is about 95t / h, and the total air volume is about 830t / h; when the load is 330MW, the coal quantity is about 150t / h, and the total air volume is about 1050t / h.

[0036]

[0037] The above on-site test data shows the change trend of the total air volume during peak shaving within a wide load range. In order to ensure that the direct current burnout air can still maintain a high flow rate and stiffness when the burnout air flow rate changes within a wide range, a burner that adapts to the wide load range of deep peak shaving and adjusts the burnout air cross-section and stiffness in stages is designed, and its working process of adjusting the burnout air cross-section and stiffness in stages is as follows.

[0038] The deep peak shaving process of thermal power units mainly focuses on the medium and low load ranges. At medium and low loads, since the total air volume changes, the air volume of the overfire air also changes accordingly, that is, the overfire air volume changes with the load. During the peak shaving process, when the overfire air volume corresponding to the current load is low, the jet velocity at the outlet of the inner overfire air duct 2 is small, the rigidity is insufficient, and the penetration depth is small, resulting in insufficient combustion support for the rising flue gas and incomplete pulverized coal combustion, which may cause problems such as an increase in unburned heat loss. To solve the above problems, the jet velocity can be increased by reducing the outlet cross-section of the inner overfire air duct 2, and the rigidity can be improved by reducing the height-width ratio of the outlet cross-section of the inner overfire air duct 2. Therefore, the outlet cross-sectional area and height-width ratio of the inner overfire air duct 2 must be changed accordingly with the change of load and air volume.

[0039] During the peak shaving process within a wide range of medium and low loads, for example, when the unit is at 50% of the rated load, the total overfire air flow is large, and the adjustment process is as Figure 8 and Figure 9 shown. The rightmost tooth of the long handle rack a9 meshes with the gear a6, the rightmost tooth of the long handle rack b10 meshes with the gear b7, and the rightmost tooth of the long handle rack c11 meshes with the gear c8. At this time, the sides (height × width) of each variable cross-section baffle are all facing the oncoming overfire air. Since the width of the variable cross-section baffle is much smaller than the side length of the square inner cross-section of the inner overfire air duct, it correspondingly presents the state of minimizing the blockage of the overfire air, and the overfire air cross-section is the largest (such as the shadow in Figure 9 ), and the height-width ratio ([[]] Figure 9 h / b in Figure 10 and Figure 11 ) is the largest. The overfire air can achieve a jet with higher velocity and rigidity for combustion support under the condition of a large air volume. When the unit is at 35% of the rated load, the total overfire air flow is moderate. At this time, it is a medium overfire air volume adjustment, and the adjustment process is as Figure 11 and Figure 11 shown. The rightmost tooth of the long handle rack a9 meshes with the gear a6. At this time, the side (height × width) of the variable cross-section baffle a3 is facing the oncoming overfire air; push the long handle rack b10 to the leftmost tooth to mesh with the gear b7. At this time, the variable cross-section baffle b4 rotates 90°, and its front (height × length) is facing the oncoming overfire air; the rightmost tooth of the long handle rack c11 meshes with the gear c8. At this time, the side (height × width) of the variable cross-section baffle c5 is facing the oncoming overfire air. The arrangement of each variable cross-section baffle correspondingly presents a state of moderately blocking the overfire air. The overfire air cross-section is evenly divided into two parts from top to bottom at equal intervals (such as the shadow in Figure 12 and Figure 13As shown in the figure, push the long handle rack a9 to the position where the leftmost tooth meshes with the gear a6, push the long handle rack b 10 to the position where the leftmost tooth meshes with the gear b7, and push the long handle rack c11 to the position where the leftmost tooth meshes with the gear c8. At this time, each variable cross-section baffle rotates 90°, and the front surfaces (height × length) are all facing the oncoming flow of the internal combustion burnout air, presenting the state of maximizing the blocking of the internal combustion burnout air. The cross-section of the internal combustion burnout air is evenly divided into four parts from top to bottom at equal intervals (such as Figure 13 the shadow in Figure 13 where h / b), the height-width ratio of each part of the cross-section is the smallest, and the total cross-sectional area is the smallest. The internal combustion burnout air can achieve a higher flow velocity and rigid jet combustion assistance under the condition of low air volume.

[0040] In summary, in different load conditions during the peak load regulation process of the thermal power unit, the present invention changes the flow cross-sectional area, the height-width ratio of the cross-section, and the rectangular cross-section distribution characteristics of the internal combustion burnout air by adjusting the arrangement mode of the variable cross-section baffles at the nozzle of the internal combustion burnout air pipe, so that the jet of the burnout air can ensure a higher jet velocity and rigidity under different load conditions, and effectively improve the combustion characteristics of the furnace flame under low load.

Claims

1. A burnout air supply characteristic adjustable burner, characterized in that: It includes an external burnout air duct (1), an internal burnout air duct (2), a variable cross-section baffle a (3), a variable cross-section baffle b (4), a variable cross-section baffle c (5), a gear a (6), a gear b (7), a gear c (8), a long-handled rack a (9), a long-handled rack b (10), and a long-handled rack c (11); the internal burnout air duct (2) includes a shaft hole a (201), a shaft hole b (202), a shaft hole c (203), a shaft hole d (204), a shaft hole e (205), a shaft hole f (206), and an internal burnout air duct housing g (207); the variable cross-section baffle a (3) includes a rotating shaft a (302) and a flat plate a (301), the variable cross-section baffle b (4) includes a rotating shaft b (402) and a flat plate b (401), and the variable cross-section baffle c (5) includes a rotating shaft c (502) and a flat plate c (501); the central axes of the external burnout air duct (1) and the internal burnout air duct (2) are arranged collinearly, and the arrangement order from outside to inside is the external burnout air duct (1) and the internal burnout air duct (2) in sequence. Both ends of each variable cross-section baffle are rotationally matched with each shaft hole on the internal burnout air duct (2), each gear is in interference fit with each variable cross-section baffle, each rack is arranged on the side surface of the internal burnout air duct (2) and is in meshing transmission with each gear; the shaft hole a (201) and the shaft hole d (204) are respectively matched with the upper and lower ends of the rotating shaft a (302), the shaft hole b (202) and the shaft hole e (205) are respectively matched with the upper and lower ends of the rotating shaft b (402), and the shaft hole c (203) and the shaft hole f (206) are respectively matched with the upper and lower ends of the rotating shaft c (502); the internal burnout air duct housing g (207) is a square-section pipe, each shaft hole is a circular hole and is in clearance fit with the rotating shaft; the rotating shaft a (302) passes through the central through hole on the side surface of the flat plate a (301), the rotating shaft b (402) passes through the central through hole on the side surface of the flat plate b (401), and the rotating shaft c (502) passes through the central through hole on the side surface of the flat plate c (501); each rotating shaft is a cylindrical metal rotating shaft, each flat plate is a rectangular parallelepiped flat plate with a central through hole, and each rotating shaft is in interference fit with each flat plate.

2. The adjustable burnout air supply characteristic burner according to claim 1, wherein: The gear a (6) is matched with the part of the upper end of the rotating shaft a (302) that extends out of the shaft hole a (201) and extends outside the internal burnout air duct (2), the gear b (7) is matched with the part of the upper end of the rotating shaft b (402) that extends out of the shaft hole b (202) and extends outside the internal burnout air duct (2), and the gear c (8) is matched with the part of the upper end of the rotating shaft c (502) that extends out of the shaft hole c (203) and extends outside the internal burnout air duct (2); each gear is a circular spur gear and is in interference fit with each rotating shaft.

3. The adjustable burner for burnout air supply characteristics according to claim 1, characterized in that: The long-handled rack a (9) is meshed with the gear a (6), the long-handled rack b (10) is meshed with the gear b (7), and the long-handled rack c (11) is meshed with the gear c (8); each rack is a rectangular parallelepiped rack and is arranged on the left side surface of the internal burnout air duct (2).

4. A burnout air supply characteristic adjustable burner according to claim 1, characterized in that: The variable cross-section baffle a (3) can rotate 90° along the axis under the adjustment of the long handle rack a (9) and the gear a (6) transmission mechanism. The variable cross-section baffle b (4) can rotate 90° along the axis under the adjustment of the long handle rack b (10) and the gear b (7) transmission mechanism. The variable cross-section baffle c (5) can rotate 90° along the axis under the adjustment of the long handle rack c (11) and the gear c (8) transmission mechanism. By rotating the variable cross-section baffle a (3), the variable cross-section baffle b (4) and the variable cross-section baffle c (5) respectively, the flow cross-sectional area, cross-sectional shape and cross-sectional distribution characteristics of the outlet of the internal combustion exhaust air duct (2) can be changed.

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