Sliding rail type adjustable structure of secondary air baffle

Abstract

This invention discloses a sliding rail adjustable structure for a secondary air baffle, comprising a secondary air duct, baffles, a slider, a rotating rod, and a support rod. The key feature is that two baffles are installed inside the secondary air duct. Guide rail grooves are formed on the walls of the baffles, and the slider is embedded in these grooves and can move along them. A cylindrical groove is formed in the vertical direction on the slider, and one end of the rotating rod is embedded in this groove and can rotate around its axial direction. The other end of the rotating rod extends out of the duct through a hole in the side wall. Adjustment is achieved using a sliding rail drive. The rotation of the rotating rod causes the slider to slide within the guide rail groove, which in turn causes the baffles to rotate. Simultaneously, the rotating rod drives the support rod to move, ensuring the stability of the baffle during rotation and enabling the opening and closing of the secondary air nozzles. The airflow speed of the secondary air is adjusted by changing the cross-sectional area of ​​the secondary air flow. This invention has a simple structure, low cost, and provides five adjustment levels to meet the needs of different operating conditions.

Description

Technical Field

[0001] This invention relates to the field of power generation technology, and in particular to a sliding rail adjustable structure for secondary air dampers in power plant boilers. Background Technology

[0002] During the operation of a power plant boiler, the secondary air velocity has a significant impact on the ignition and combustion of pulverized coal. Secondary air delivers air into the furnace to participate in combustion and enhances airflow turbulence, promoting the recirculation of high-temperature flue gas and providing conditions for complete combustion. When the boiler load changes, the combustion situation in the furnace also changes: when the secondary air velocity is too low, it cannot reach the center of the furnace, failing to enhance the contact and mixing between air and the surface of coke particles; when the secondary air velocity is too high, it impacts the downstream primary air-coal flow, affecting combustion stability and increasing incomplete combustion losses.

[0003] The adjustment of secondary air velocity can be achieved by changing the flow cross-sectional area at the end of the secondary air duct. However, the baffles currently used to adjust the cross-sectional area generally suffer from high flow resistance, deflection of the secondary air jet center, disruption of the secondary air tangential circle within the furnace, or the need to replace pipe fittings to achieve multi-level adjustment. When baffles are installed inside the air duct, traditional vertically inserted baffles generate significant local resistance, leading to a loss of secondary air kinetic energy. Even with oblique insertion, although local resistance is reduced, the baffle must be inserted obliquely to the edge of the pipe outlet to adjust the secondary air velocity. In this case, the obliquely inserted baffle cannot achieve multi-level air velocity adjustment and cannot adapt to the requirements of variable operating conditions. These baffle problems cause inconvenience in actual operation and adjustment, and may even affect the stability of boiler combustion.

[0004] Against the backdrop of advocating dual-carbon goals and reducing carbon emissions, more and more generating units have undergone flexibility retrofitting, continuously enhancing their peak-shaving capabilities. During peak-shaving, fluctuations in unit load are inevitable, making complete and stable combustion in the boiler particularly crucial. Therefore, to meet the requirements of changing unit operating conditions, regulate secondary air velocity, and overcome the problems of existing dampers, a new type of secondary air damper regulation structure is needed. Summary of the Invention

[0005] The purpose of this invention is to improve the traditional secondary air duct structure and provide a novel sliding rail-type adjustable structure for power plant boilers. In this adjustable structure, a secondary air baffle is built into the side of the air duct. Driven by a rotating rod, three sliders on the baffle slide, thereby changing the flow cross-sectional area of ​​the duct and adjusting the secondary air velocity to adapt to the requirements of boiler load changes, ensuring complete combustion and improving combustion efficiency. This secondary air duct structure is simple and inexpensive.

[0006] The aforementioned adjustable sliding structure includes: a secondary air duct 1, baffle a2, baffle b3, slider a4, slider b5, rotating rod a6, rotating rod b7, support rod a8, and support rod b9; wherein the secondary air duct 1 includes an upper wall 101, a lower wall 102, a side wall 103, straight grooves a104, b105, c106, d107, e108, f109, holes a110 and b111, fixing blocks a112 and b113, cylindrical grooves a114 and b115, and scale plates a116 and b117; the baffle a2 includes a rotating shaft a201 and a rotating shaft b202. Guide rail grooves a203, b204, c205, and T-slot a206; baffle b3 includes rotating shaft c301, rotating shaft d302, guide rail groove d303, guide rail groove e304, guide rail groove f305, and T-slot b306; slider a4 has an internal cylindrical groove c401; slider b5 has an internal cylindrical groove d501; rotating rod a6 includes rotating shaft e601, rotating shaft f602, and hole c603; rotating rod b7 includes rotating shaft g701, rotating shaft h702, and hole d703; support rod a8 includes rotating shaft i801, rotating shaft j802, and rotating shaft k803; support rod b9 includes rotating shaft l901, rotating shaft m902, and rotating shaft n903.

[0007] Among them, baffles a2 and b3 are located at the end outlet of the secondary air duct 1. By rotating baffles a2 and b3 at different angles, five gears are provided to control the secondary air speed. The relative motion between baffles a2 and b3 and the side wall 103 of the air duct adopts the line contact high pair motion. The motion mode of sliders a4 and b5 adopts the combination of revolute and prismatic joint in the surface contact low pair motion. The driving mode of rotating rods a6 and b7 adopts the combination of revolute and prismatic joint in the surface contact low pair motion.

[0008] The secondary air duct 1 has a sidewall 103 on each of its left and right sides, for a total of two sidewalls 103. The upper wall 101 of the air duct has straight grooves a104, c106, and e108 on its inner side, and the lower wall 102 of the air duct has straight grooves b105, d107, and f109 on its inner side. The sidewalls 103 have holes a110 and b111. Fixing blocks a112 and b113 are installed on the inner side of the sidewalls 103, and cylindrical grooves a114 and b115 are respectively formed vertically inside the fixing blocks a112 and b113. Scale plates a116 and b117 are connected to the left and right sides of the sidewalls 103, respectively.

[0009] The straight grooves a104, b105, c106, and d107 on the inner side of the secondary air duct 1 have the same structure. The straight grooves a104 and c106 are symmetrically distributed on the upper wall 101 of the air duct, and the straight grooves b105 and d107 are symmetrically distributed on the lower wall 102 of the air duct. The straight grooves e108 and f109 have the same structure and are symmetrically distributed. The holes a110 and b111, the fixing blocks a112 and b113, and the scale plates a116 and b117 have the same structure and are symmetrically distributed on the side wall 103 of the air duct.

[0010] The secondary air duct 1, together with baffles a2 and baffles b3, forms a secondary air circulation channel. Based on the size of the circulation cross-sectional area, the adjustment state is divided into five levels: ①, ②, ③, ④, and ⑤. The larger the number, the larger the circulation cross-sectional area. At level ①, the rotating shaft a201 of baffle a2 is in contact with the rotating shaft c301 of baffle b3, and the circulation cross-sectional area is zero; at this time, the secondary air duct 1 is in the closed state. At level ②, the rotating shaft a201 of baffle a2 is separated from the rotating shaft c301 of baffle b3, and the circulation cross-sectional area is 1 / 4 of the cross-sectional area of ​​the secondary air duct 1. At the maximum wind speed, when in setting ③, the pivot a201 of baffle a2 and the pivot c301 of baffle b3 are further separated, and the flow cross-sectional area is 2 / 4 of the cross-sectional area of ​​secondary air duct 1; when in setting ④, the pivot a201 of baffle a2 and the pivot c301 of baffle b3 are further separated, and the flow cross-sectional area is 3 / 4 of the cross-sectional area of ​​secondary air duct 1; when in setting ⑤, baffle a2 and b3 are attached to the side wall 103 of the air duct respectively. Ignoring the thickness of baffle a2 and b3, the flow cross-sectional area is approximately equal to the cross-sectional area of ​​secondary air duct 1, and the secondary wind speed is the minimum.

[0011] The upper surfaces of the scale plates a116 and b117 are marked with five positions: ①, ②, ③, ④ and ⑤, which are used to indicate the positions of the rotating rods a6 and b7 in different positions.

[0012] The baffle a2 is equipped with a rotating shaft a201 and a rotating shaft b202 at its two ends respectively. The end of the rotating shaft a201 near the upper wall 101 of the air duct forms a groove fit with the straight groove e108, and the end near the lower wall 102 of the air duct forms a groove fit with the straight groove f109. The rotating shaft a201 can slide horizontally along the straight groove e108 and the straight groove f109 along the edge of the outlet of the secondary air duct 1. The end of the rotating shaft b202 near the upper wall 101 of the air duct forms a groove fit with the straight groove a104, and the end near the lower wall 102 of the air duct forms a groove fit with the straight groove b105. The rotating shaft b202 can slide horizontally along the straight groove a104 and the straight groove b105 along the side wall 103 of the air duct. The horizontal sliding of the rotating shafts a201 and b202 can drive the baffle a2 to rotate relative to the side wall 103 of the secondary air duct 1, with a rotation angle not exceeding 50°.

[0013] The baffle a2 has horizontally oriented guide rail grooves a203, b204, c205, and a T-shaped slot a206. A slider a4 is embedded in each of the guide rail grooves a203, b204, and c205, for a total of three sliders a4. Each slider a4 has a vertically oriented cylindrical groove c401, and the three sliders a4 can slide horizontally within the guide rail grooves a203, b204, and c205, respectively.

[0014] The baffle b3 is equipped with a rotating shaft c301 and a rotating shaft d302 at its two ends, respectively. The end of the rotating shaft c301 near the upper wall 101 of the air duct forms a groove with the straight groove e108, and the end near the lower wall 102 of the air duct forms a groove with the straight groove f109. The rotating shaft c301 can slide horizontally along the straight groove e108 and the straight groove f109 along the edge of the outlet of the secondary air duct 1. The end of the rotating shaft d302 near the upper wall 101 of the air duct forms a groove with the straight groove c106, and the end near the lower wall 102 of the air duct forms a groove with the straight groove d107. The rotating shaft d302 can slide horizontally along the straight groove c106 and the straight groove d107 along the side wall 103 of the air duct. The horizontal sliding of the rotating shafts c301 and d302 can drive the baffle b3 to rotate relative to the side wall 103 of the secondary air duct 1, with a rotation angle not exceeding 50°.

[0015] The baffle b3 has horizontally oriented guide rail grooves d303, e304, f305, and a T-shaped slot b306. A slider b5 is embedded in each of the guide rail grooves d303, e304, and f305, for a total of three sliders b5. Each slider b5 has a vertically oriented cylindrical groove d501, and the three sliders b5 can slide horizontally within the guide rail grooves d303, e304, and f305, respectively.

[0016] The baffles a2 and b3 have the same structure, the guide rail grooves a203, b204, d303 and e304 have the same structure, the guide rail grooves c205 and f305 have the same structure, and the three sliders a4 and b5 have the same structure. During the adjustment process, the spatial positions of the baffles a2 and b3 are always symmetrically distributed. The baffles a2 and b3 form a clearance fit with the secondary air duct 1, with a clearance of 1 mm.

[0017] The rotating rod a6 has a rotating shaft e601 and a rotating shaft f602. The rotating shaft e601 is embedded in the cylindrical groove a114 of the fixed block a112, and the rotating rod a6 can rotate around the axial direction of the cylindrical groove a114. The rotating shaft f602 is embedded in the cylindrical groove c401 of the slider a4 located on the guide rail groove c205, and the rotating rod a6 can rotate around the axial direction of the cylindrical groove c401. The rotating shaft e601 and the rotating shaft f602 form a clearance fit with the cylindrical groove a114 and the cylindrical groove c401 respectively, with a clearance of 1mm.

[0018] The rotating rod b7 has a rotating shaft g701 and a rotating shaft h702. The rotating shaft g701 is embedded in the cylindrical groove b115 of the fixed block b113, and the rotating rod b7 can rotate around the axial direction of the cylindrical groove b115. The rotating shaft h702 is embedded in the cylindrical groove d501 of the slider b5 located on the guide rail groove f305, and the rotating rod b7 can rotate around the axial direction of the cylindrical groove d501. The rotating shaft g701 and the rotating shaft h702 form a clearance fit with the cylindrical groove b115 and the cylindrical groove d501, respectively, with a clearance of 1 mm.

[0019] The support rod a8 has a rotating shaft i801, a rotating shaft j802, and a rotating shaft k803. The rotating shaft i801 and the rotating shaft j802 are respectively embedded in the cylindrical grooves c401 of the two sliders a4 located on the guide rail grooves a203 and b204. The rotating shaft i801 and the rotating shaft j802 form a clearance fit with the cylindrical groove c401, with a clearance of 1mm. The support rod a8 can rotate around the axial direction of the cylindrical groove c401. The rotating shaft k803 passes through the hole c603 on the rotating rod a6 and can rotate around the axial direction of the hole c603. The rotating shaft k803 forms a clearance fit with the hole c603, with a clearance of 1mm.

[0020] The support rod b9 has a rotating shaft l901, a rotating shaft m902, and a rotating shaft n903. The rotating shafts l901 and m902 are respectively embedded in the cylindrical grooves d501 of the two sliders b5 located on the guide rail grooves d303 and e304. The rotating shafts l901 and m902 form a clearance fit with the cylindrical grooves d501, with a clearance of 1mm. The support rod b9 can rotate around the axial direction of the cylindrical grooves d501. The rotating shaft n903 passes through the hole d703 on the rotating rod b7 and can rotate around the axial direction of the hole d703. The rotating shaft n903 forms a clearance fit with the hole d703, with a clearance of 1mm.

[0021] The rotating rods a6 and b7 have identical structures, as do the support rods a8 and b9. During adjustment, the spatial positions of the rotating rods a6 and b7 are always symmetrically distributed, and the positions of the scale plates a116 and b117 are characterized by their spatial positions.

[0022] The adjustment state has five levels, each of which can work independently, providing five different secondary air speeds (the air speed is 0 when the flow cross-sectional area is 0). When the opening of the secondary air duct 1 reaches its minimum, the rotating shafts a201 of baffle a2 and c301 of baffle b3 come into contact, and the duct is closed. When the opening of the secondary air duct 1 reaches its maximum, baffles a2 and b3 are respectively attached to the side wall 103 of the air duct. At this time, one end of the fixed block a112 and the rotating rod a6 is embedded in the T-slot a206, and one end of the fixed block b113 and the rotating rod b7 is respectively embedded in the T-slot b306.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: In this invention, the rotation of rotating rods a6 and b7, through the surface contact lower pair of the rotating and prismatic joints, drives the sliding of sliders a4 and b5, thereby rotating baffles a2 and b3. This changes the flow cross-sectional area of ​​the secondary air, allowing for adjustment of the secondary air velocity under the same secondary air volume. This invention, through modification of the secondary air duct end and simultaneous adjustment of baffles a2 and b3, ensures that the center of the secondary air jet remains straight. Depending on the degree of rotation of baffles a2 and b3, five levels of adjustment of the secondary air velocity can be achieved, meeting the requirements of different operating conditions. This secondary air duct structure is simple and inexpensive. Attached Figure Description

[0024] Figure 1 This is a front view of the slide rail adjustable structure of the present invention; Figure 2 This is an external view of the slide rail adjustable structure of the present invention; Figure 3 This is a partially enlarged view of the slide rail adjustable structure of the present invention; Figure 4 This is a top view of the slide rail adjustable structure of the present invention; Figure 5 This is a bottom view of the slide rail adjustable structure of the present invention; Figure 6 These are the front view and sectional view of the baffle a2 of the present invention; Figure 7 These are the front view and sectional view of the baffle b3 of the present invention; Figure 8 These are the front view, perspective view, and sectional view of slider a4 and slider b5 of the present invention; Figure 9 This is a perspective view of the rotating rod a6 and rotating rod b7 of the present invention; Figure 10 This is a perspective view of the support rod a8 and support rod b9 of the present invention; Figure 11 The scale markings of scale plate a116 and scale plate b117 of the present invention are for the stop markings. Figure 12 This is a schematic diagram of the first gear of the slide rail adjustable structure of the present invention; Figure 13 This is a schematic diagram of the second position of the slide rail adjustable structure of the present invention; Figure 14 This is a schematic diagram of the ③ position of the slide rail adjustable structure of the present invention; Figure 15 This is a schematic diagram of the fourth position of the slide rail adjustable structure of the present invention; Figure 16 This is a schematic diagram of the fifth position of the slide rail adjustable structure of the present invention; Figure Label Explanation: 1-Secondary air duct; 101-Upper wall of air duct; 102-Lower wall of air duct; 103-Side wall of air duct; 104-Straight groove a; 105-Straight groove b; 106-Straight groove c; 107-Straight groove d; 108-Straight groove e; 109-Straight groove f; 110-Hole a; 111-Hole b; 112-Fixing block a; 113-Fixing block b; 114-Cylindrical groove a; 115-Cylindrical groove b; 116-Scale plate a; 117-Scale plate b; 2-Baffle a; 201-Rotating shaft a; 202-Rotating shaft b; 203-Guide rail groove a; 204-Guide rail groove b; 205-Guide rail groove c; 206-T-slot a; 3-Baffle Plate b; 301-Shaft c; 302-Shaft d; 303-Guide rail groove d; 304-Guide rail groove e; 305-Guide rail groove f; 306-T-slot b; 4-Slider a; 401-Cylindrical groove c; 5-Slider b; 501-Cylindrical groove d; 6-Rotating rod a; 601-Shaft e; 602-Shaft f; 603-Hole c; 7-Rotating rod b; 701-Shaft g; 702-Shaft h; 703-Hole d; 8-Support rod a; 801-Shaft i; 802-Shaft j; 803-Shaft k; 9-Support rod b; 901-Shaft l; 902-Shaft m; 903-Shaft n; ①, ②, ③, ④, ⑤-Five adjustment positions. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments, and the scope of the description will be defined so that the advantages and features of the present invention can be more easily understood by those skilled in the art.

[0026] like Figures 1-16As shown, the present invention is a sliding rail adjustable structure for a secondary air damper in a power plant boiler, including a secondary air duct 1, a damper a2, a damper b3, a slider a4, a slider b5, a rotating rod a6, a rotating rod b7, a support rod a8, and a support rod b9; the secondary air duct 1 includes an upper wall 101, a lower wall 102, a side wall 103, straight grooves a104, b105, c106, d107, e108, f109, holes a110 and b111, fixing blocks a112 and b113, cylindrical grooves a114 and b115, a scale plate a116, and a scale plate b117; the damper a2 includes a rotating shaft a201 and a rotating shaft b20. 2. Guide rail grooves a203, b204, c205, and T-slot a206; the baffle b3 includes a rotating shaft c301, a rotating shaft d302, a guide rail groove d303, a guide rail groove e304, a guide rail groove f305, and a T-slot b306; the slider a4 has a cylindrical groove c401 inside; the slider b5 has a cylindrical groove d501 inside; the rotating rod a6 includes a rotating shaft e601, a rotating shaft f602, and a hole c603; the rotating rod b7 includes a rotating shaft g701, a rotating shaft h702, and a hole d703; the support rod a8 includes a rotating shaft i801, a rotating shaft j802, and a rotating shaft k803; the support rod b9 includes a rotating shaft l901, a rotating shaft m902, and a rotating shaft n903.

[0027] The baffles a2 and b3 are located at the end outlet of the secondary air duct 1. Their purpose is to adjust the secondary air velocity by adjusting the flow area at the end outlet of the secondary air duct 1.

[0028] The relative motion between baffles a2 and b3 and the duct sidewall 103 adopts a line contact high-pair motion. The motion of sliders a4 and b5 adopts a combination of revolute and prismatic joints in surface contact low-pair motion. The driving method of rotating rods a6 and b7 adopts a combination of revolute and prismatic joints in surface contact low-pair motion. Through this sliding rail driving method, on the one hand, baffles a2 and b3 can be reliably and stably rotated to adjust the flow cross-sectional area of ​​the duct. On the other hand, it can ensure that the rotation shafts a201 of baffles a2 and c301 of baffles b3 are always close to the edge of the duct outlet. When the opening is at its maximum, baffles a2 and b3 are attached to the duct sidewall 103, minimizing local resistance. When the opening is reduced, the tilt angle of baffles a2 and b3 can also ensure that there is no excessive local resistance to the secondary air.

[0029] There is a duct sidewall 103 on each of the left and right sides of the secondary air duct 1, for a total of two duct sidewalls 103.

[0030] The inner side of the upper wall 101 of the air duct has straight grooves a104, c106 and e108. The inner side of the lower wall 102 of the air duct has straight grooves b105, d107 and f109. The side wall 103 of the air duct has holes a110 and b111. On the inner side of the side wall 103 of the air duct, fixing blocks a112 and b113 are respectively installed. The fixing blocks a112 and b113 have cylindrical grooves a114 and b115 respectively in the vertical direction. The left and right sides of the side wall 103 of the air duct are connected to scale plates a116 and b117 respectively.

[0031] The straight slots a104, b105, c106, and d107 have the same structure. The straight slots a104 and c106 are symmetrically distributed on the upper wall 101 of the air duct, and the straight slots b105 and d107 are symmetrically distributed on the lower wall 102 of the air duct. The straight slots e108 and f109 have the same structure and are symmetrically distributed. The holes a110 and b111, the fixing blocks a112 and b113, and the scale plates a116 and b117 have the same structure and are symmetrically distributed on the side wall 103 of the air duct.

[0032] The baffle a2 is equipped with a rotating shaft a201 and a rotating shaft b202 at its two ends respectively. The end of the rotating shaft a201 near the upper wall 101 of the air duct forms a groove fit with the straight groove e108, and the end near the lower wall 102 of the air duct forms a groove fit with the straight groove f109. The rotating shaft a201 can slide horizontally along the straight groove e108 and the straight groove f109 along the edge of the outlet of the secondary air duct 1. The end of the rotating shaft b202 near the upper wall 101 of the air duct forms a groove fit with the straight groove a104, and the end near the lower wall 102 of the air duct forms a groove fit with the straight groove b105. The rotating shaft b202 can slide horizontally along the straight groove a104 and the straight groove b105 along the side wall 103 of the air duct. The horizontal sliding of the rotating shafts a201 and b202 can drive the baffle a2 to rotate relative to the side wall 103 of the secondary air duct 1, with a rotation angle not exceeding 50°.

[0033] The baffle a2 has horizontally oriented guide rail grooves a203, b204, c205, and a T-shaped slot a206. Each of the guide rail grooves a203, b204, and c205 contains a slider a4, for a total of three sliders a4. Each slider a4 has a vertically oriented cylindrical groove c401 inside, and the three sliders a4 can slide horizontally in the guide rail grooves a203, b204, and c205 respectively.

[0034] The baffle b3 is equipped with a rotating shaft c301 and a rotating shaft d302 at its two ends, respectively. The end of the rotating shaft c301 near the upper wall 101 of the air duct forms a groove fit with the straight groove e108, and the end near the lower wall 102 of the air duct forms a groove fit with the straight groove f109. The rotating shaft c301 can slide horizontally along the straight groove e108 and the straight groove f109 along the edge of the outlet of the secondary air duct 1. The end of the rotating shaft d302 near the upper wall 101 of the air duct forms a groove fit with the straight groove c106, and the end near the lower wall 102 of the air duct forms a groove fit with the straight groove d107. The rotating shaft d302 can slide horizontally along the straight groove c106 and the straight groove d107 along the side wall 103 of the air duct. The horizontal sliding of the rotating shafts c301 and d302 can drive the baffle b3 to rotate relative to the side wall 103 of the secondary air duct 1, with a rotation angle not exceeding 50°.

[0035] The baffle b3 has horizontally oriented guide rail grooves d303, e304, f305, and a T-shaped slot b306. Each of the guide rail grooves d303, e304, and f305 has a slider b5 embedded in it, for a total of three sliders b5. Each slider b5 has a vertically oriented cylindrical groove d501 inside it, and the three sliders b5 can slide horizontally in the guide rail grooves d303, e304, and f305 respectively.

[0036] Baffles a2 and b3 have the same structure; guide rail grooves a203, b204, d303, and e304 have the same structure; guide rail grooves c205 and f305 have the same structure; and the three sliders a4 and b5 have the same structure. During adjustment, the spatial positions of baffles a2 and b3 are always symmetrically distributed. Baffles a2 and b3 form a clearance fit with the secondary air duct 1, with a clearance of 1 mm.

[0037] Secondary air duct 1, together with baffles a2 and baffles b3, forms the secondary air circulation duct. According to the size of the circulation cross-sectional area, the adjustment state is divided into five positions: ①, ②, ③, ④ and ⑤. The larger the number, the larger the circulation cross-sectional area. When it is in position ①, the rotating shaft a201 of baffle a2 is in contact with the rotating shaft c301 of baffle b3, and the circulation cross-sectional area is zero. At this time, secondary air duct 1 is in the closed state. When in position ②, the pivot a201 of baffle a2 separates from the pivot c301 of baffle b3, and the flow cross-sectional area is 1 / 4 of the cross-sectional area of ​​secondary air duct 1, at which point the secondary air velocity is at its maximum. When in position ③, the pivot a201 of baffle a2 and the pivot c301 of baffle b3 move further apart, and the flow cross-sectional area is 2 / 4 of the cross-sectional area of ​​secondary air duct 1. When in position ④, the pivot a201 of baffle a2 and the pivot c301 of baffle b3 move further apart, and the flow cross-sectional area is 3 / 4 of the cross-sectional area of ​​secondary air duct 1. When in position ⑤, baffles a2 and b3 are attached to the side wall 103 of the air duct, and ignoring the thickness of baffles a2 and b3, the flow cross-sectional area is approximately equal to the cross-sectional area of ​​secondary air duct 1, at which point the secondary air velocity is at its minimum.

[0038] The rotating rod a6 has a rotating shaft e601 and a rotating shaft f602. The rotating shaft e601 is embedded in the cylindrical groove a114 of the fixed block a112, and the rotating rod a6 can rotate around the axial direction of the cylindrical groove a114. The rotating shaft f602 is embedded in the cylindrical groove c401 of the slider a4 located on the guide rail groove c205, and the rotating rod a6 can rotate around the axial direction of the cylindrical groove c401. The rotating shaft e601 and the rotating shaft f602 form a clearance fit with the cylindrical groove a114 and the cylindrical groove c401 respectively, with a clearance of 1mm.

[0039] The rotating rod b7 has a rotating shaft g701 and a rotating shaft h702. The rotating shaft g701 is embedded in the cylindrical groove b115 of the fixed block b113, and the rotating rod b7 can rotate around the axial direction of the cylindrical groove b115. The rotating shaft h702 is embedded in the cylindrical groove d501 of the slider b5 located on the guide rail groove f305, and the rotating rod b7 can rotate around the axial direction of the cylindrical groove d501. The rotating shaft g701 and the rotating shaft h702 form a clearance fit with the cylindrical groove b115 and the cylindrical groove d501 respectively, with a clearance of 1mm.

[0040] The support rod a8 has rotating shafts i801, j802, and k803. Rotating shafts i801 and j802 are respectively embedded in the cylindrical grooves c401 of the two sliders a4 located on the guide rail grooves a203 and b204. Rotating shafts i801 and j802 form a clearance fit with the cylindrical grooves c401 with a clearance of 1mm. The support rod a8 can rotate around the axial direction of the cylindrical grooves c401. Rotating shaft k803 passes through the hole c603 on the rotating rod a6 and can rotate around the axial direction of the hole c603. Rotating shaft k803 forms a clearance fit with the hole c603 with a clearance of 1mm.

[0041] The support rod b9 has a rotating shaft l901, a rotating shaft m902, and a rotating shaft n903. The rotating shafts l901 and m902 are respectively embedded in the cylindrical grooves d501 of the two sliders b5 located on the guide grooves d303 and e304. The rotating shafts l901 and m902 form a clearance fit with the cylindrical grooves d501, with a clearance of 1mm. The support rod b9 can rotate around the axial direction of the cylindrical grooves d501. The rotating shaft n903 passes through the hole d703 on the rotating rod b7 and can rotate around the axial direction of the hole d703. The rotating shaft n903 forms a clearance fit with the hole d703, with a clearance of 1mm.

[0042] Rotating rod a6 and rotating rod b7 have identical structures, as do supporting rod a8 and supporting rod b9. During adjustment, the spatial positions of rotating rod a6 and rotating rod b7 are always symmetrically distributed, and the positions of scale plates a116 and b117 are characterized by their spatial positions.

[0043] The adjustment state has five levels, each of which can work independently, providing five different secondary air speeds (the air speed is 0 when the flow cross-sectional area is 0). When the opening of the secondary air duct 1 reaches its minimum, the rotating shafts a201 of baffle a2 and c301 of baffle b3 come into contact, and the duct is closed. When the opening of the secondary air duct 1 reaches its maximum, baffles a2 and b3 are respectively attached to the side wall 103 of the air duct. At this time, one end of the fixed block a112 and the rotating rod a6 is embedded in the T-slot a206, and one end of the fixed block b113 and the rotating rod b7 is respectively embedded in the T-slot b306. The flow cross-sectional area of ​​the duct is approximately equal to the cross-sectional area of ​​the secondary air duct 1.

[0044] This invention modifies the end of the secondary air duct 1 and simultaneously adjusts baffles a2 and b3 to ensure the center of the secondary air jet remains straight and the tangential circle inside the furnace is not disrupted. By rotating rotating rods a6 and b7, the movement of the rotating and translating joints of the surface contact lower pair drives the sliding of sliders a4 and b5, thereby rotating baffles a2 and b3 and changing the flow cross-sectional area of ​​the secondary air. Under the same secondary air volume, the secondary air velocity can be adjusted. Depending on the degree of rotation of baffles a2 and b3, five levels of adjustment of the secondary air velocity can be achieved, meeting the requirements of different operating conditions and demonstrating the innovation and practicality of this invention.

[0045] The working principle of this invention is as follows: During the airflow within secondary air duct 1, the secondary air volumetric flow rate is equal to the product of the flow cross-sectional area and the secondary air velocity. Under the same secondary air volume, increasing the flow cross-sectional area leads to a decrease in secondary air velocity, and vice versa. During boiler combustion, when the boiler load increases, the secondary air volume needs to be increased to ensure complete combustion; in this case, the flow cross-sectional area needs to be adjusted to prevent a sudden increase in secondary air velocity. Conversely, when the boiler load decreases, the secondary air volume needs to be reduced; in this case, the flow cross-sectional area needs to be adjusted to prevent a sudden drop in secondary air velocity.

[0046] When baffles are installed inside the duct, traditional vertically inserted baffles will generate significant local resistance, resulting in the loss of secondary air kinetic energy. Even if the baffles are inserted at an angle, they must be inserted to the same level as the edge of the duct outlet to adjust the secondary air velocity. In this case, the angled baffles cannot achieve multi-level air velocity adjustment and cannot adapt to the requirements of variable operating conditions.

[0047] In this invention, secondary air duct 1, baffle a2, and baffle b3 together form the secondary air flow channel. As rotating rods a6 and b7 are rotated, their interlocking sliders a4 and b5 slide horizontally within straight slots c106 and f109, respectively. Consequently, baffles a2 and b3, constrained by straight slots c106 and f109, rotate within secondary air duct 1. During rotation, rotating shafts b202 and d302 remain attached to the sidewall 103 of the air duct, while rotating shafts a201 and c301 close towards each other and open in opposite directions along straight slots e108 and f109, ultimately adjusting the cross-sectional area of ​​the secondary air flow. The adjustment states are divided into five levels: ①, ②, ③, ④, and ⑤, allowing for five levels of adjustment for different operating conditions. At the same time, support rods a8 and b9 drive the interlocking sliders a4 and b5 to slide, respectively, which plays a supporting and stabilizing role in the rotation of baffles a2 and b3.

[0048] The working process of this invention will be clearly and specifically described below through three embodiments, taking into account the specific needs of the application scenario.

[0049] Example 1: When it is necessary to reduce the secondary air velocity, first rotate the rotating rod a6 counterclockwise from top to bottom until the rotating rod a6 coincides with the ⑤ mark on the scale plate a116. At this time, the three sliders a4 slide horizontally in the guide rail grooves a203, b204, and c205 respectively, thereby causing the baffle a2 to rotate within the secondary air duct 1 and be adjusted to the correct position. Similarly, rotate the rotating rod b7 clockwise from top to bottom until the rotating rod b7 coincides with the ⑤ mark on the scale plate b117. At this time, the three sliders a4 slide horizontally in the guide rail grooves a203, b204, and c205 respectively, thereby causing the baffle a2 to rotate within the secondary air duct 1 and be adjusted to the correct position. The sliders b5 slide horizontally in the guide rail grooves d303, e304, and f305 respectively, thereby causing the baffle b3 to rotate within the secondary air duct 1 and be adjusted into position. At this time, the baffles a2 and b3 are attached to the side wall 103 of the air duct, the rotating rod a6 and the fixed block a112 are embedded in the T-slot a206, and the rotating rod b7 and the fixed block b113 are embedded in the T-slot b306. The cross-sectional area of ​​the secondary airflow reaches its maximum, and the secondary air velocity reaches its minimum under the same secondary air volume.

[0050] Example 2: When it is necessary to increase the secondary air velocity, first, looking down, rotate the rotating rod a6 clockwise until it coincides with the second-position scale line of the scale plate a116. At this time, the three sliders a4 slide horizontally in the guide rail grooves a203, b204, and c205 respectively, thereby causing the baffle a2 to rotate within the secondary air duct 1 and be adjusted to the correct position. Similarly, looking down, rotate the rotating rod b7 counterclockwise until it coincides with the second-position scale line of the scale plate b117. At this time, the three sliders b5 slide horizontally in the guide rail grooves d303, e304, and f305 respectively, thereby causing the baffle b3 to rotate within the secondary air duct 1 and be adjusted to the correct position. At this time, the flow cross-sectional area of ​​the secondary air increases, and the secondary air velocity increases under the same secondary air volume.

[0051] Example 3: When it is necessary to close the secondary air duct 1, first, looking down, rotate the rotating rod a6 clockwise until it coincides with the ① mark on the scale plate a116. At this time, the three sliders a4 slide horizontally in the guide rail grooves a203, b204, and c205, respectively, thereby causing the baffle a2 to rotate within the secondary air duct 1 and be adjusted to the correct position. Similarly, looking down, rotate the rotating rod b7 counterclockwise until it coincides with the ① mark on the scale plate b117. At this time, the three sliders b5 slide horizontally in the guide rail grooves d303, e304, and f305, respectively, thereby causing the baffle b3 to rotate within the secondary air duct 1 and be adjusted to the correct position. At this time, the rotating shafts a201 and c301 come into contact, and the secondary air flow channel is closed.

[0052] The above three embodiments are preferred embodiments of the present invention. It should be noted that the above three embodiments represent different working states of the same slide rail adjustable structure, and each of the three embodiments can operate independently; the five positions ①, ②, ③, ④, and ⑤ are also five working states of the same slide rail adjustable structure, and each of the five positions can also operate independently. In summary, the slide rail adjustable structure proposed in this invention uses five positions to adjust the secondary air velocity through slide rail drive, ensuring sufficient and stable combustion of the boiler under varying operating conditions. This secondary air duct structure is simple, inexpensive, easy to modify, and highly practical.

Claims

1. A sliding rail adjustable structure for a secondary air damper, characterized in that, include: Secondary air duct (1), baffle a (2), baffle b (3), slider a (4), slider b (5), rotating rod a (6), rotating rod b (7), support rod a (8) and support rod b (9); the secondary air duct (1) includes an upper wall (101), a lower wall (102), a side wall (103), straight groove a (104), straight groove b (105), straight groove c (106), straight groove d (107), straight groove e (108), straight groove f (109), hole a (110), hole b (111), fixing block a (112), fixing block b (113), cylindrical groove a (114), cylindrical groove b (115), scale plate a (116) and scale plate b (117); The baffle a (2) includes a rotating shaft a (201), a rotating shaft b (202), a guide rail groove a (203), a guide rail groove b (204), a guide rail groove c (205), and a T-shaped slot a (206). The windward side of the baffle a (2) has no through-holes or exposed connecting parts. During movement, the baffle a (2) achieves full-range movement limitation through the cooperation of the slidable rotating shafts at both ends with the corresponding straight slots. There are no fixed fulcrums. The guide rail grooves a (203), b (204), c (205), and a T-shaped slot a (206) are all arranged on the leeward side of the baffle a (2). The baffle b (3) includes a rotating shaft c (301), a rotating shaft d (302), a guide rail groove d (303), a guide rail groove e (304), and a guide rail groove f (305). 5) and T-slot b (306), wherein the windward side of the baffle b (3) has no through parts or exposed connecting parts. During the movement, the baffle b (3) achieves full-range movement limitation through the sliding rotating shafts at both ends and the corresponding straight slots. There is no fixed support point. The guide rail grooves d (303), e (304), f (305) and T-slot b (306) are all arranged on the leeward side of the baffle b (3). The slider a (4) has a cylindrical groove c (401) inside. The slider b (5) has a cylindrical groove d (501) inside. The rotating rod a (6) includes a rotating shaft e (601), a rotating shaft f (602) and a hole c (603). The rotating rod b (7) includes a rotating shaft g (701), a rotating shaft h (702) and Hole d (703); The support rod a (8) includes rotating shaft i (801), rotating shaft j (802) and rotating shaft k (803); The support rod b (9) includes rotating shaft l (901), rotating shaft m (902) and rotating shaft n (903); Among them, the positions of baffle a (2) and baffle b (3) are located at the end outlet of the secondary air duct (1); The relative motion between baffle a (2) and baffle b (3) and the side wall (103) of the air duct adopts the high pair motion of line contact, the motion mode of slider a (4) and slider b (5) adopts the combination of rotary pair and prismatic pair in the low pair motion of surface contact, and the driving mode of rotating rod a (6) and rotating rod b (7) adopts the combination of rotary pair and prismatic pair in the low pair motion of surface contact;Rotating rod a(6) is connected to baffle a(2) and support rod a(8) respectively, forming a triangular support structure. Rotating rod b(7) is connected to baffle b(3) and support rod b(9) respectively, forming a triangular support structure.

2. The slide rail adjustable structure according to claim 1, characterized in that: The secondary air duct (1) has straight grooves a (104), c (106), and e (108) on the inner side of the upper wall (101), and straight grooves b (105), d (107), and f (109) on the inner side of the lower wall (102). The air duct sidewall (103) has holes a (110) and b (111). On the inner side of the air duct sidewall (103), fixing blocks a (112) and b (113) are respectively installed. The fixing blocks a (112) and b (113) have cylindrical grooves a (114) and b (115) respectively in the vertical direction. The left and right sides of the air duct sidewall (103) are connected to scale plates a (116) and scales respectively. Plate b (117); The straight grooves a (104), b (105), c (106) and d (107) inside the secondary air duct (1) have the same structure. Among them, straight grooves a (104) and c (106) are symmetrically distributed on the upper wall (101) of the air duct, and straight grooves b (105) and d (107) are symmetrically distributed on the lower wall (102) of the air duct. Straight grooves e (108) and f (109) have the same structure and are symmetrically distributed. Holes a (110) and b (111), fixing blocks a (112) and b (113), scale plates a (116) and b (117) have the same structure and are symmetrically distributed on the side wall (103) of the air duct.

3. The slide rail adjustable structure according to claim 1, characterized in that: The baffle a (2) is equipped with a rotating shaft a (201) and a rotating shaft b (202) at its two ends respectively. The end of the rotating shaft a (201) near the upper wall (101) of the air duct forms a groove fit with the straight groove e (108), and the end near the lower wall (102) of the air duct forms a groove fit with the straight groove f (109). The rotating shaft a (201) can slide horizontally along the straight groove e (108) and the straight groove f (109) along the edge of the outlet of the secondary air duct (1). The end of the rotating shaft b (202) near the upper wall (101) of the air duct forms a groove fit with the straight groove a (104), and the end near the lower wall (102) of the air duct forms a groove fit with the straight groove b (105). The rotating shaft b (202) can slide along the straight groove a (104) and the straight groove b (105) along the side wall (103) of the air duct. Horizontal sliding; the horizontal sliding of the rotating shaft a (201) and the rotating shaft b (202) can drive the baffle a (2) to rotate relative to the side wall (103) of the secondary air duct (1), with a rotation angle not exceeding 50°; the baffle a (2) has guide rail grooves a (203), guide rail grooves b (204), guide rail grooves c (205) and T-shaped slots a (206) along the horizontal direction on the wall surface; a slider a (4) is embedded in each of the guide rail grooves a (203), guide rail grooves b (204) and guide rail grooves c (205), for a total of three sliders a (4); the slider a (4) has a cylindrical groove c (401) along the vertical direction inside, and the three sliders a (4) can slide horizontally in the guide rail grooves a (203), guide rail grooves b (204) and guide rail grooves c (205) respectively.

4. The slide rail adjustable structure according to claim 1, characterized in that: The baffle b (3) is equipped with a rotating shaft c (301) and a rotating shaft d (302) at its two ends respectively. The end of the rotating shaft c (301) near the upper wall (101) of the air duct forms a groove fit with the straight groove e (108), and the end near the lower wall (102) of the air duct forms a groove fit with the straight groove f (109). The rotating shaft c (301) can slide horizontally along the straight groove e (108) and the straight groove f (109) along the edge of the outlet of the secondary air duct (1). The end of the rotating shaft d (302) near the upper wall (101) of the air duct forms a groove fit with the straight groove c (106), and the end near the lower wall (102) of the air duct forms a groove fit with the straight groove d (107). The rotating shaft d (302) can slide horizontally along the straight groove c (106) and the straight groove d (107) along the side wall (103) of the air duct. Horizontal sliding; the horizontal sliding of the rotating shaft c (301) and the rotating shaft d (302) can drive the baffle b (3) to rotate relative to the side wall (103) of the secondary air duct (1), with a rotation angle not exceeding 50°; the baffle b (3) has guide rail grooves d (303), e (304), f (305) and T-shaped slot b (306) along the horizontal direction on the wall surface; a slider b (5) is embedded in each of the guide rail grooves d (303), e (304) and f (305), for a total of three sliders b (5); the slider b (5) has a cylindrical groove d (501) along the vertical direction inside, and the three sliders b (5) can slide horizontally in the guide rail grooves d (303), e (304) and f (305) respectively.

5. The slide rail adjustable structure according to claim 1, characterized in that: The baffles a (2) and baffles b (3) have the same structure. The guide rail grooves a (203), b (204), d (303) and e (304) have the same structure. The guide rail grooves c (205) and f (305) have the same structure. The three sliders a (4) and b (5) have the same structure. The rotating rods a (6) and b (7) have the same structure. The support rods a (8) and b (9) have the same structure. During the adjustment process, the spatial positions of baffles a (2) and baffles b (3) are always symmetrically distributed. Baffles a (2) and baffles b (3) form a clearance fit with the secondary air duct (1), with a clearance of 1 mm. The spatial positions of rotating rods a (6) and b (7) are always symmetrically distributed. The position of scale plate a (116) and scale plate b (117) is characterized by the spatial positions of rotating rods a (6) and b (7).

6. The slide rail type adjustable structure according to claim 1, characterized in that: The rotating rod a (6) has a rotating shaft e (601) and a rotating shaft f (602). The rotating shaft e (601) is embedded in the cylindrical groove a (114) of the fixed block a (112), and the rotating rod a (6) can rotate around the axial direction of the cylindrical groove a (114). The rotating shaft f (602) is embedded in the cylindrical groove c (401) of the slider a (4) located on the guide rail groove c (205), and the rotating rod a (6) can rotate around the axial direction of the cylindrical groove c (401). The rotating shaft e (601) and the rotating shaft f (602) form a clearance fit with the cylindrical groove a (114) and the cylindrical groove c (401) respectively, with a clearance of 1 mm.

7. The slide rail type adjustable structure according to claim 1, characterized in that: The rotating rod b (7) has a rotating shaft g (701) and a rotating shaft h (702). The rotating shaft g (701) is embedded in the cylindrical groove b (115) of the fixed block b (113), and the rotating rod b (7) can rotate around the axial direction of the cylindrical groove b (115). The rotating shaft h (702) is embedded in the cylindrical groove d (501) of the slider b (5) located on the guide rail groove f (305), and the rotating rod b (7) can rotate around the axial direction of the cylindrical groove d (501). The rotating shaft g (701) and the rotating shaft h (702) form a clearance fit with the cylindrical groove b (115) and the cylindrical groove d (501) respectively, and the clearance is 1mm.

8. The slide rail adjustable structure according to claim 1, characterized in that: The support rod a (8) has a rotating shaft i (801), a rotating shaft j (802) and a rotating shaft k (803). The rotating shaft i (801) and the rotating shaft j (802) are respectively embedded in the cylindrical groove c (401) of the two sliders a (4) located on the guide rail groove a (203) and the guide rail groove b (204). The rotating shaft i (801) and the rotating shaft j (802) form a clearance fit with the cylindrical groove c (401) with a clearance of 1 mm. The support rod a (8) can rotate around the axial direction of the cylindrical groove c (401). The rotating shaft k (803) passes through the hole c (603) on the rotating rod a (6) and can rotate around the axial direction of the hole c (603). The rotating shaft k (803) forms a clearance fit with the hole c (603) with a clearance of 1 mm.

9. The slide rail type adjustable structure according to claim 1, characterized in that: The support rod b (9) has a rotating shaft l (901), a rotating shaft m (902) and a rotating shaft n (903). The rotating shaft l (901) and the rotating shaft m (902) are respectively embedded in the cylindrical groove d (501) of the two sliders b (5) located on the guide groove d (303) and the guide groove e (304). The rotating shaft l (901) and the rotating shaft m (902) form a clearance fit with the cylindrical groove d (501) with a clearance of 1 mm. The support rod b (9) can rotate around the axial direction of the cylindrical groove d (501). The rotating shaft n (903) passes through the hole d (703) on the rotating rod b (7) and can rotate around the axial direction of the hole d (703). The rotating shaft n (903) forms a clearance fit with the hole d (703) with a clearance of 1 mm.

10. The slide rail type adjustable structure according to claim 1, characterized in that: The adjustment state is divided into five gears, and the five gears can work independently, providing five different secondary air speeds (the air speed is 0 when the flow cross-sectional area is 0); when the opening of the secondary air duct (1) reaches the minimum, the rotating shaft a (201) of the baffle a (2) and the rotating shaft c (301) of the baffle b (3) come into contact, and the duct is closed; when the opening of the secondary air duct (1) reaches the maximum, the baffle a (2) and the baffle b (3) are respectively attached to the side wall (103) of the air duct, at which time one end of the fixed block a (112) and the rotating rod a (6) are embedded in the T-shaped slot a (206), and one end of the fixed block b (113) and the rotating rod b (7) are respectively embedded in the T-shaped slot b (306).

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