Fire coal feeding device for thermal power station power generation boiler

Abstract

The invention relates to a fire coal feeding device for a power generation boiler of a thermal power station, and belongs to the technical field of coal powder supply of coal-fired power generation boilers, the fire coal feeding device is configured and connected between a coal mill and a boiler, and comprises a mounting frame and a coal powder conveying assembly arranged on the mounting frame, and the coal powder conveying assembly comprises an inner pipe horizontally arranged on the mounting frame; the inner pipe is rotationally connected with the mounting frame in the circumferential direction of the inner pipe, the multiple stirring strips are fixedly arranged on the inner wall of the inner pipe in a surrounding mode at equal intervals and are spirally arranged, and the output end of the first driving element is connected with the inner pipe. And then the first driving element is used for driving the inner pipe to rotate, when the pulverized coal with the large particle size in the outer layer of the air flow gathers towards the lower side of the inner pipe, the pulverized coal is continuously shifted to the upper side of the air flow in the inner pipe by the shifting strip, the pulverized coal moves towards the center of the air flow through the gravity of the pulverized coal to achieve mixing, and the situation that the pulverized coal is deposited in the feeding process is avoided.

Description

Technical Field

[0001] This invention belongs to the field of pulverized coal supply technology for coal-fired power generation boilers, and specifically relates to a coal feeding device for power plant boilers. Background Technology

[0002] Thermal power plants typically use coal as fuel. The fuel is burned in a boiler, releasing a large amount of heat energy to heat water into steam. This steam then drives a turbine to power a generator. Although there are many existing power generation methods, thermal power is more stable than other methods, providing a continuous and stable power output. It is suitable for large-scale baseload power generation, and thermal power technology is mature, equipment is reliable, and operation and maintenance are relatively simple. Therefore, thermal power remains one of the main power generation methods. However, because the boilers in thermal power plants need to continuously burn coal during operation, carbon dioxide emissions are high. Especially when coal combustion is incomplete, large amounts of sulfur dioxide, carbon monoxide, nitrogen oxides, and soot are emitted, causing significant environmental pollution.

[0003] To mitigate the environmental pollution caused by thermal power plants, modifications to boilers are often implemented, such as the adoption of pulverized coal boilers. In these systems, coal is ground into powder by a coal mill, and then the powder is carried by airflow along a pipe between the mill and the boiler, fed into nozzles. The pulverized coal is then injected into the boiler's combustion chamber in pulses or intermittently, utilizing the larger contact area provided by the powder to ensure rapid and complete combustion, thus preventing the formation of harmful substances. However, during the operation of thermal power plants, it has been found that pulverized coal easily accumulates in the pipes transporting it. This accumulated coal softens when heated, clumps together, and adheres to the inner wall of the pipe. Over time, the increasing accumulation of coal not only corrodes the pipe itself but also, if the clumps break off, can clog the nozzles, affecting the stability of the pulverized coal boiler's operation.

[0004] An investigation of the pipelines and the pulverized coal itself revealed that, because the pulverized coal produced by the coal mill ranges in size from 50 to 100 micrometers, larger particles tend to accumulate and deposit as the airflow carries the coal through the pipeline. Currently, thermal power plants often increase the output airflow velocity of the blower to prevent pulverized coal deposition during the feeding process, thereby enhancing the suspension capacity of the pulverized coal and preventing the deposition of larger particles due to gravity. However, because the pipeline used to transport pulverized coal between the coal mill and the pulverized coal boiler has a certain length, the kinetic energy of the pulverized coal is lost as the airflow moves through it, causing the airflow velocity to decrease in the latter half of the pipeline. Larger particles gradually accumulate in the lower layer of the airflow, resulting in pulverized coal deposition still occurring on the side of the pipeline near the pulverized coal boiler, thus offering limited improvement to the pulverized coal deposition problem in the pipeline. Summary of the Invention

[0005] In view of this, the present invention provides a coal feeding device for a power plant boiler to overcome the shortcomings of the prior art. The present invention can increase the overall flow velocity of the airflow and enhance the suspension capacity of coal powder particles, thereby preventing coal powder from settling during feeding.

[0006] The technical solution of this invention is: a coal feeding device for a thermal power plant boiler, configured and connected between a coal mill and a boiler to input pulverized coal ground by the coal mill into the nozzle of the boiler. The device includes a mounting frame and a pulverized coal conveying assembly mounted on the mounting frame. The mounting frame is fixed between the coal mill and the boiler. The pulverized coal conveying assembly includes an inner tube horizontally mounted on the mounting frame, rotatably connected to the mounting frame around its circumference. One end of the inner tube communicates with the coal mill's hopper, and the other end communicates with the boiler's nozzle. The side of the coal mill's hopper furthest from the inner tube... A fan is installed to drive pulverized coal into the inner tube and move it along its length. Multiple actuating bars are fixedly arranged around the inner wall of the inner tube at equal intervals. The multiple actuating bars are arranged in a spiral shape so that the airflow drives the pulverized coal to move in a spiral along the length of the inner tube. The first driving element is installed on the mounting frame. The output end of the first driving element is connected to the inner tube and is used to drive the inner tube to rotate around its circumference, and the rotation direction is opposite to that of the actuating bars, so that the actuating bars continuously drive the airflow and pulverized coal located on the lower side of the inner tube to move upward.

[0007] Preferably, the spiral angle α at both ends of the toggle bar is in the range of 20°~45°.

[0008] Preferably, the longitudinal section of the actuating bar is semi-circular, and the outer diameter of the actuating bar increases from one end near the coal mill to the other end, with the side of the actuating bar near the coal mill smoothly transitioning to the inner wall of the inner tube.

[0009] Preferably, an impact rod is vertically positioned directly below the inner tube and located on the side of the inner tube away from the coal mill. The impact rod is slidably connected to the mounting frame along its length. A second driving element is provided on the mounting frame, and the output end of the second driving element is connected to the end of the impact rod away from the inner tube, so as to drive the impact rod to move back and forth to impact the inner tube.

[0010] Preferably, multiple U-shaped support seats are fixed radially at equal intervals on the outer side of the inner tube, and multiple impact rods are arranged in a one-to-one correspondence on the U-shaped support seats. The impact rods are slidably connected to the U-shaped support seats along the radial direction of the inner tube, and springs are sleeved on the impact rods. The second driving element is replaced by a traction mechanism. The output end of the traction mechanism is movably connected to the impact rod to drive the impact rod to slide away from the inner tube. When the impact rod is located on the lower side of the inner tube, the impact rod is released so that the spring drives the impact rod to continuously impact the inner tube.

[0011] Preferably, the traction mechanism includes: an arc-shaped chute and multiple limiting rods. The arc-shaped chute is fixed directly below the inner tube and parallel to its center line. The longitudinal section of the arc-shaped chute is concave. The multiple limiting rods are fixed one-to-one at the end of the impact rod away from the inner tube. One end of the arc-shaped chute is inclined towards the inner tube so that the impact rod drives the limiting rod into the arc-shaped chute and slides along its circumference. The arc-shaped chute has a notch located directly below the inner tube. The width of the notch is greater than the length of the limiting rod so that the limiting rod slides out of the arc-shaped chute from the notch.

[0012] Preferably, the arc-shaped groove has multiple notches arranged at equal intervals, the width of the multiple notches increases sequentially along the rotation direction of the inner tube, the multiple impact rods are divided into multiple groups, the number of impact rods in each group is equal to the number of notches, the length of multiple limiting rods on each group of impact rods and the width of multiple notches increase sequentially along the rotation direction of the inner tube, so that the limiting rods of the same group of impact rods slide out of the arc-shaped groove from the notches at the same time.

[0013] Preferably, an annular buffer pad is fitted onto the inner tube, and the annular buffer pad is arranged opposite to the impact rod.

[0014] Preferably, a spherical impact head is fixed at one end of the impact rod near the inner tube, and the spherical impact head is made of rubber.

[0015] Compared with the prior art, the present invention provides a coal feeding device for a thermal power plant boiler. Through the cooperation of the mounting frame and the inner tube and actuating bars of the pulverized coal conveying component, when the airflow output by the fan drives the pulverized coal along the inner tube toward the nozzle of the boiler, the actuating bars arranged in a spiral shape make the airflow drive the pulverized coal to move in a spiral shape in the inner tube. This can increase the overall flow velocity of the airflow, thereby enhancing the suspension ability of the pulverized coal particles and reducing the settling speed of larger pulverized coal particles. Then, the first driving element drives the inner tube to rotate, and the rotation direction of the inner tube is opposite to the spiral direction of the actuating bars. When the larger pulverized coal particles in the outer layer of the airflow gather to the lower side of the inner tube, they are continuously pushed to the upper side of the airflow in the inner tube by the actuating bars. This part then moves toward the center of the airflow by its own gravity to achieve mixing, thereby avoiding the deposition of pulverized coal during feeding. Attached Figure Description

[0016] Figure 1 This is a top view of the feeding device of the present invention; Figure 2 This is the present invention. Figure 1 AA section view; Figure 3 This is the present invention. Figure 1 BB section view; Figure 4 This is the present invention. Figure 1 CC section view; Figure 5This is a side view of the inner tube of the present invention; Figure 6 This is a cross-sectional view of the inner tube of the present invention; Figure 7 This is a top view of the arc-shaped slide groove of the present invention; Figure 8 This is a front view of the feeding device of the present invention; Figure 9 This is a side view of the feeding device of the present invention. Detailed Implementation

[0017] This invention provides a coal feeding device for a thermal power plant boiler, which is described below in conjunction with... Figures 1 to 9 The present invention is illustrated by the structural diagram shown below.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] Reference Figure 1 , Figure 2 , Figure 1 This is a top view of the feeding device in this embodiment. Figure 2 This is a cross-sectional view (AA) of the feeding device in this embodiment. A coal feeding device for a power plant boiler is configured to connect a coal mill and a boiler to feed pulverized coal ground by the coal mill into the boiler nozzles. It includes a mounting frame and a pulverized coal conveying assembly mounted on the mounting frame. The mounting frame is fixed between the coal mill and the boiler. The pulverized coal conveying assembly includes an inner tube 1 horizontally mounted on the mounting frame. The inner tube 1 is rotatably connected to the mounting frame around its circumference. One end of the inner tube 1 communicates with the coal mill's hopper, and the other end communicates with the boiler nozzles. The side of the coal mill's hopper furthest from the inner tube 1... A fan is provided to drive pulverized coal into the inner tube 1 through airflow and move it along its length. Multiple actuating bars 2 are fixedly arranged around the inner wall of the inner tube 1 at equal intervals. The multiple actuating bars 2 are arranged in a spiral shape so that the airflow drives the pulverized coal to move in a spiral along the length of the inner tube 1. The first driving element is set on the mounting frame. The output end of the first driving element is connected to the inner tube 1 and is used to drive the inner tube 1 to rotate around its circumference, which is opposite to the spiral direction of the actuating bars 2, so that the actuating bars 2 continuously drive the airflow and pulverized coal located on the lower side of the inner tube 1 to move upward.

[0020] In this embodiment, the coal feeding device for the power plant boiler is arranged between the coal mill and the boiler. One end of the inner tube 1 is connected to the coal mill's hopper. A fan located on the side of the hopper away from the inner tube 1 outputs airflow, which carries the pulverized coal obtained from grinding into the inner tube 1. The other end of the inner tube 1 is connected to the nozzle on the pulverized coal furnace. When the airflow carries the pulverized coal in the inner tube 1, it is guided by multiple spirally arranged actuating strips 2, which make the airflow in the inner tube 1 carry the pulverized coal in a spiral motion. This increases the flow velocity of the airflow, thereby enhancing the suspension capacity of the pulverized coal in the airflow and reducing the downward settling speed of larger pulverized coal particles. When the airflow carries the pulverized coal in a spiral motion in the inner tube 1, the larger pulverized coal particles on the outer layer of the airflow will move closer to the inner tube 1 due to centrifugal force. Therefore, the part closer to the lower side of the inner tube 1... Larger coal particles tend to settle more quickly. In this embodiment, the first driving element is used to rotate the inner tube, and the rotation direction of the inner tube 1 is opposite to the spiral direction of the agitator bar 2. The inner tube 1 actively drives the agitator bar 2 to rotate. When the larger coal particles in the outer layer of the airflow gather towards the lower side of the inner tube, the agitator bar 2 pushes the outer airflow and the larger coal particles upward. On the one hand, the larger coal particles move to the upper side of the airflow and then move towards the center of the airflow through their own gravity to achieve mixing. On the other hand, the pushed outer airflow collides with the airflow that was originally spiraling inside. The two airflows (the pushed outer airflow and the airflow that was originally spiraling inside) and the coal particles mix with each other, causing the larger coal particles to move towards the center of the airflow, further preventing the larger coal particles from settling during feeding.

[0021] Specifically, refer to Figure 8 , Figure 9 , Figure 8 This is a front view of the feeding device in this embodiment. Figure 9 This is a side view of the feeding device in this embodiment. The mounting frame includes: a base 3 and an outer tube 4 horizontally fixed on the base 3. An inner tube 1 is disposed in the outer tube 4 and is coaxial with its center line. The inner tube 1 is rotatably connected to the outer tube 4 around its circumference. A first driving element is arranged in the middle of the inner side of the outer tube 4. The two ends of the outer tube 4 are respectively connected to the hopper of the coal mill and the nozzle of the boiler. A sealing mechanism is provided between the two ends of the inner tube 1 and the outer tube 4 to prevent coal powder from entering between the inner tube 1 and the outer tube 4.

[0022] Specifically, refer to Figure 3 , Figure 3 This is a BB cross-sectional view of the feeding device in this embodiment. The first driving element is a motor 8. The motor 8 is fixed on the inner wall of the outer tube 4 and located in the middle of the outer tube 4. A drive gear 81 is fixedly mounted on the output shaft of the motor 8. A driven gear 82 is mounted on the outer side of the inner tube 1. The drive gear 81 and the driven gear 82 mesh with each other, thereby driving the inner tube 1 to rotate.

[0023] Specifically, the sealing mechanism includes two annular support plates 5, which are fixed at both ends of the outer tube 4 and coaxial with its center line. The annular support plate 5 near the boiler nozzle is sleeved on the inner tube 1. The other annular support plate 5 has an annular groove 51 on the side away from the coal mill hopper. The annular groove 51 is coaxial with the center line of the annular support plate 5. The end of the inner tube 1 near the coal mill hopper is inserted into the annular groove 51. The inner tube 1 is rotatably connected to the two annular support plates 5 around its circumference.

[0024] The coal feeding device for the power plant boiler in the above embodiment requires an inner tube 1 to connect the hopper of the coal mill to the nozzle on the pulverized coal boiler, so as to transport the pulverized coal obtained from grinding to the nozzle on the pulverized coal boiler. Specifically, an inlet pipe 6 is provided inside the annular support plate 5 near the hopper of the coal mill. The inlet pipe 6 is fixedly connected to the annular support plate 5. One end of the inlet pipe 6 extends into the inner tube 1, and the other end is connected to the hopper of the coal mill, so that the airflow carries the pulverized coal smoothly into the inner tube 1. Another annular support plate 5 has an outlet pipe 7 on its outer side, which is coaxial with its center line. One end of the outlet pipe 7 is fixedly connected to the annular support plate 5, and the other end is connected to the nozzle on the pulverized coal boiler, so that the airflow carries the pulverized coal smoothly from the inner tube 1 into the nozzle of the boiler.

[0025] Specifically, after the pulverizer grinds the coal to obtain coal powder, it falls into the silo. A screw feeder is installed at the bottom of the silo so that the coal powder falls from the lower end of the screw feeder at a uniform speed. The inlet of the blower is arranged directly opposite the lower end of the screw feeder. The airflow is used to drive the falling coal powder to move towards the inlet of the inlet pipe 6 and finally enter the inlet pipe 6.

[0026] Specifically, the outer and inner diameters of the inlet pipe 6 within the inner pipe 1 decrease from the side furthest from the inner pipe 1 to the other side. The gradual decrease in inner diameter concentrates the coal powder entering the inner pipe 1 with the airflow, reducing the settling speed of the coal powder. On the other hand, it prevents the inner pipe 1 from colliding with the inlet pipe 6 due to axial runout when it rotates. The inner diameter of the outlet pipe 7 gradually decreases from the side closest to the inner pipe 1 to the other side, which can again concentrate the airflow and coal powder output from the inner pipe 1 in the middle area of ​​the nozzle flow channel, further ensuring the uniformity of the coal powder sprayed from the nozzle.

[0027] In the above specific embodiment, by utilizing the structure of the gradually decreasing inner diameter of the inlet pipe 6 and the outlet pipe 7, the airflow entering the inner pipe 1 and exiting the inner pipe 1 can be accelerated again, thereby improving the suspension ability of coal powder in the airflow. This not only prevents coal powder from settling in the inner pipe 1, but also prevents coal powder from settling in the flow channel of the nozzle. At the same time, the sudden increase in airflow speed will make the airflow more turbulent, resulting in violent fluctuations and disturbances in the airflow. These fluctuations help to mix and evenly distribute the coal powder particles.

[0028] In this embodiment, besides being fixedly connected to the inner wall of the inner tube 1, the actuating strip 2 can also be connected in the following way: the outer side of the actuating strip 2 (the side away from the center line of the inner tube 1) abuts against the inner wall of the inner tube 1, one end of the actuating strip 2 is fixedly connected to the outer side of the inlet pipe 6, and the other end extends into the outlet pipe 7 and is fixedly connected to its inner wall. In this case, the actuating strip 2 is used to guide the airflow in the inner tube 1, so that the airflow drives the coal powder to move in a spiral shape in the inner tube, which can improve the overall flow velocity of the airflow.

[0029] Reference Figure 5 , Figure 5 This is a side view of the inner tube in this embodiment. As a further optimization, the spiral angle α at both ends of the toggle bar 2 in this embodiment ranges from 20° to 45°.

[0030] In this embodiment, when the spiral angle α at both ends of the agitator bar 2 is in the range of 20°~45°, it can ensure that while driving the airflow and coal powder to move in a spiral shape, the centrifugal force on the coal powder particles is reduced as much as possible. This improves the suspension ability of coal powder in the airflow while reducing the impact of centrifugal force on the coal powder.

[0031] Specifically, in this embodiment, when the particle size of the coal powder is 50 micrometers, the spiral angle α at both ends of the actuating strip 2 is 20°; when the particle size of the coal powder is 75 micrometers, the spiral angle α at both ends of the actuating strip 2 is 30°; and when the particle size of the coal powder is 100 micrometers, the spiral angle α at both ends of the actuating strip 2 is 45°.

[0032] Reference Figure 6 , Figure 6 This is a cross-sectional view of the inner tube in this embodiment. As a further optimization, the longitudinal section of the actuating bar 2 in this embodiment is semi-circular, and the outer diameter of the actuating bar 2 increases from one end near the coal mill to the other end. The side of the actuating bar 2 near the coal mill is smoothly transitioned to the inner wall of the inner tube 1.

[0033] In this embodiment, a semi-circular longitudinal section of the agitator strip 2 is used to reduce the resistance encountered by the airflow when it moves in a spiral shape. The outer diameter of the agitator strip 2 increases from the end closest to the coal mill to the other end. The side of the agitator strip 2 closest to the coal mill is smoothly transitioned to the inner wall of the inner tube 1. This ensures that the agitator strip 2 guides the airflow in a spiral shape and its ability to agitate the outer layer of airflow increases from the end closest to the coal mill to the other end. This is because the kinetic energy loss of the airflow is small when it first enters the inner tube 1, and the airflow can provide suspension for the coal powder on its own, making it less likely for the coal powder to settle. As the airflow moves along the inner tube 1, kinetic energy is lost. The increase in the outer diameter of the agitator strip 2 continuously improves the ability to guide the airflow in a spiral shape and its ability to agitate the outer layer of airflow, preventing the airflow from moving in a spiral shape too early and causing the coal powder to be subjected to excessive centrifugal force.

[0034] In this embodiment, based on the actual movement state of the pulverized coal in the inner tube 1, the longitudinal section and outer diameter of the actuating bar 2 are optimized to further ensure the smooth feeding of the pulverized coal.

[0035] As can be seen from the aforementioned embodiments, the outer diameter of the agitator bar 2 increases from one end near the coal mill to the other end. When the agitator bar 2 drives the outer airflow and coal powder to move upward, there is a situation where coal powder accumulates on both sides of the agitator bar 2. As the outer diameter of the agitator bar 2 continues to increase, it is easier for coal powder to accumulate, which is not conducive to the smooth feeding of coal powder.

[0036] Based on the above problems, this embodiment provides a solution: an impact rod 11 is vertically arranged directly below the inner tube 1 and is located on the side of the inner tube 1 away from the coal mill. The impact rod 11 is slidably connected to the mounting frame along its length. A second driving element is provided on the mounting frame. The output end of the second driving element is connected to the end of the impact rod 11 away from the inner tube 1 so as to drive the impact rod 11 to move back and forth to impact the inner tube 1.

[0037] In this embodiment, the impact rod 11 is used in conjunction with the second driving element. The second driving element drives the impact rod 11 to move back and forth to impact the inner tube 1, so that the coal powder gathered on both sides of the toggle bar 2 re-enters the airflow for mixing, thus preventing the coal powder from agglomerating. Since the impact is a vertically upward vibration, the coal powder particles near the lower side of the inner tube 1 gain upward kinetic energy, further preventing the coal powder from depositing during feeding.

[0038] Specifically, the second driving element can be a linear output device such as a cylinder.

[0039] In the above embodiment, when the inner tube 1 rotates, the impact rod strikes the inner tube vertically upward, causing the impact direction of the impact rod to shift to the rotating side of the inner tube. This affects the effect of the coal powder particles on the lower side of the inner tube 1 moving towards the center of the airflow for re-mixing. Furthermore, after the shift, the impact rod is prone to friction with the outer side of the inner tube 1, causing damage to the inner tube.

[0040] Based on the above problems, this embodiment optimizes the impact rod: multiple U-shaped support seats 12 are fixed radially and equally spaced on the outer side of the inner tube 1, and multiple impact rods 11 are arranged, and the arrangement is replaced by one-to-one correspondence through the U-shaped support seats 12. The impact rods 11 are slidably connected to the U-shaped support seats 12 along the radial direction of the inner tube 1, and springs 13 are respectively sleeved on the impact rods 11. The second driving element is replaced by a traction mechanism. The output end of the traction mechanism is movably connected to the impact rods 11 to drive the impact rods 11 to slide away from the inner tube 1. When the impact rods 11 are located on the lower side of the inner tube 1, the impact rods 11 are released so that the springs 13 drive the impact rods 11 to continuously impact the inner tube 1.

[0041] In this embodiment, the U-shaped support 12 is used to change the arrangement of the impact rods 11 from being mounted on the mounting frame to being mounted on the outside of the inner tube 1. Multiple impact rods 11 are arranged radially along the inner tube 1. The traction mechanism drives the impact rods 11 to slide away from the inner tube 1. After the impact rods 11 are released, the spring 13 drives the impact rods 11 to continuously impact the inner tube 1. Each impact direction of the impact rods 11 passes through the center of the inner tube 1 to avoid the impact rods from deviating. The spring is used as the power source for the impact, which can avoid excessive driving force that could damage the outside of the inner tube 1. This ensures that the coal powder particles on the lower side of the inner tube 1 move towards the airflow center for re-mixing, and further prevents the coal powder from settling during feeding.

[0042] Reference Figure 4 , Figure 4 This is a CC cross-sectional view of the feeding device in this embodiment. As a further optimization, the traction mechanism in this embodiment includes: an arc-shaped chute 14 and multiple limiting rods 15. The arc-shaped chute 14 is fixed directly below the inner tube 1 and parallel to its center line. The longitudinal section of the arc-shaped chute 14 is concave. The multiple limiting rods 15 are fixed one-to-one at the end of the impact rod 11 away from the inner tube 1. One end of the arc-shaped chute 14 is inclined towards the inner tube 1 so that the impact rod 11 drives the limiting rod 15 into the arc-shaped chute 14 and slides along its circumference. A notch 16 is provided on the arc-shaped chute 14 and is located directly below the inner tube 1. The width of the notch 16 is greater than the length of the limiting rod 15 so that the limiting rod 15 slides out of the arc-shaped chute 14 from the notch 16.

[0043] In this embodiment, the traction mechanism consists of an arc-shaped groove 14 and multiple limiting rods 15, so that when the inner tube 1 rotates, it drives the impact rod 11 and the limiting rod 15 on its outer side to rotate synchronously. Since one end of the arc-shaped groove 14 is inclined to the inner tube 1, the limiting rod 15 at the end of the impact rod 11 slides into the arc-shaped groove 14 in sequence, and the impact rod 11 drives the limiting rod 15 to move along the arc-shaped groove 14. When the limiting rod 15 moves to the notch 16 on the arc-shaped groove 14, since the width of the notch 16 is greater than the length of the limiting rod 15, the limiting rod 15 slides out of the arc-shaped groove 14 from the notch 16, so that the spring 13 drives the impact rod 11 to impact the inner tube 1.

[0044] Specifically, in this embodiment, the longitudinal section of the arc-shaped slide 14 is concave, and the limiting rod 15 at the end of the impact rod 11 is arranged along the center line of the inner tube. The concave shape of the arc-shaped slide 14 is used to limit the limiting rod 15, so that the limiting rod 15 moves along the arc-shaped slide 14.

[0045] As a further optimization, in this embodiment, multiple notches 16 are arranged at equal intervals on the arc-shaped slide groove 14. The width of the multiple notches 16 increases sequentially along the rotation direction of the inner tube 1. The multiple impact rods 11 are divided into multiple groups. The number of impact rods 11 in each group is equal to the number of notches 16. The length of the multiple limiting rods 15 on each group of impact rods 11 and the width of the multiple notches 16 increase sequentially along the rotation direction of the inner tube 1, so that the limiting rods 15 of the same group of impact rods 11 can slide out of the arc-shaped slide groove 14 from the notches at the same time.

[0046] In this embodiment, the impact rods 11 on the outer side of the inner tube 1 are evenly divided into multiple groups, and the notches 16 on the arc-shaped groove 14 correspond to the same number of impact rods 11 in each group. The multiple notches 16 are located directly below the inner tube 1 and are symmetrical about a vertical line passing through the center of the inner tube 1. Figure 7 , Figure 7 This is a top view of the arc-shaped chute in this embodiment. In this embodiment, there are three impact rods 11 in each group, and three notches 16 are also arranged on the arc-shaped chute 14. The width of the three notches 16 increases from right to left, and the length of the limiting rods 15 on the three impact rods 11 also increases sequentially. This allows the limiting rods 15 of the same group of impact rods 11 to slide out of the arc-shaped chute 14 from the corresponding notches 16 at the same time. This allows multiple impact rods 11 to impact from the lower side of the inner tube 1 at the same time, and the impact direction is always aligned with the center of the inner tube 1. This improves the effect of the coal powder particles on the lower side of the inner tube 1 moving towards the center of the airflow for re-mixing, thereby preventing coal powder from depositing during feeding.

[0047] As a further optimization, in this embodiment, an annular buffer pad is fitted on the inner tube 1, and the annular buffer pad is arranged opposite to the impact rod 11.

[0048] In this embodiment, an annular buffer pad is used to ensure that the impact rod 11 impacts the inner tube 1, while avoiding deformation of the inner tube 1 due to repeated impacts of the impact rod 11, thus preventing coal powder from accumulating and further preventing coal powder from depositing during feeding.

[0049] As a further optimization, in this embodiment, a spherical impact head 17 is fixed at one end of the impact rod 11 near the inner tube 1, and the spherical impact head 17 is made of rubber.

[0050] In this embodiment, the spherical impact head 17 is used so that when the impact rod 11 impacts, the impact energy is transferred to the coal powder in the inner tube 1 in a relatively gentle manner, so as to prevent the violent energy of the impact from affecting the airflow and causing the coal powder to move normally in the inner tube 1.

[0051] The above-disclosed embodiments are merely preferred embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A coal feeding device for a thermal power plant boiler, configured and connected between a coal mill and a boiler, for feeding pulverized coal ground by the coal mill into the nozzles of the boiler, characterized in that, include: A mounting frame and a pulverized coal conveying assembly mounted on the mounting frame, the mounting frame being fixed between the coal mill and the boiler, the pulverized coal conveying assembly comprising: The inner tube is horizontally mounted on the mounting frame. The inner tube is rotatably connected to the mounting frame around its circumference. One end of the inner tube is connected to the hopper of the coal mill, and the other end is connected to the nozzle of the boiler. A fan is installed on the side of the hopper of the coal mill away from the inner tube so as to drive the coal powder into the inner tube through airflow and move it along its length. Multiple actuating strips are fixedly arranged around the inner wall of the inner tube at equal intervals. The multiple actuating strips are arranged in a spiral shape so that the airflow drives the coal powder to move in a spiral along the length of the inner tube. A first driving element is disposed on the mounting bracket. The output end of the first driving element is connected to the inner tube and is used to drive the inner tube to rotate around its circumference, which is opposite to the spiral direction of the actuating bar, so that the actuating bar continuously drives the airflow and coal powder located on the lower side inside the inner tube to move upward.

2. The coal feeding device for a thermal power plant boiler according to claim 1, characterized in that, The spiral angle α at both ends of the toggle bar ranges from 20° to 45°.

3. The coal feeding device for a power plant boiler according to claim 1, characterized in that, The longitudinal section of the actuating bar is semi-circular, and the outer diameter of the actuating bar increases from one end near the coal mill to the other end. The side of the actuating bar near the coal mill is smoothly transitioned to the inner wall of the inner tube.

4. The coal feeding device for a thermal power plant boiler according to claim 1, characterized in that, An impact rod is vertically positioned directly below the inner tube and located on the side of the inner tube away from the coal mill. The impact rod is slidably connected to the mounting frame along its length. A second driving element is provided on the mounting frame. The output end of the second driving element is connected to the end of the impact rod away from the inner tube, so as to drive the impact rod to move back and forth to impact the inner tube.

5. The coal feeding device for a thermal power plant boiler according to claim 4, characterized in that, Multiple U-shaped support seats are fixed radially and evenly spaced on the outer side of the inner tube. Multiple impact rods are arranged in a one-to-one correspondence and are inserted into the U-shaped support seats. The impact rods are slidably connected to the U-shaped support seats along the radial direction of the inner tube. Each impact rod is fitted with a spring. The second driving element is replaced by a traction mechanism. The output end of the traction mechanism is movably connected to the impact rod to drive the impact rod to slide away from the inner tube. When the impact rod is located on the lower side of the inner tube, the impact rod is released so that the spring drives the impact rod to continuously impact the inner tube.

6. The coal feeding device for a thermal power plant boiler according to claim 5, characterized in that, The traction mechanism includes an arc-shaped chute and multiple limiting rods. The arc-shaped chute is fixed directly below the inner tube and parallel to its center line. The longitudinal section of the arc-shaped chute is concave. The multiple limiting rods are fixed one-to-one at the end of the impact rod away from the inner tube. One end of the arc-shaped chute is inclined towards the inner tube so that the impact rod drives the limiting rod into the arc-shaped chute and slides along its circumference. The arc-shaped chute has a notch located directly below the inner tube. The width of the notch is greater than the length of the limiting rod so that the limiting rod slides out of the arc-shaped chute from the notch.

7. The coal feeding device for a thermal power plant boiler according to claim 6, characterized in that, The arc-shaped groove has multiple notches arranged at equal intervals. The width of the multiple notches increases sequentially along the rotation direction of the inner tube. The multiple impact rods are divided into multiple groups. The number of impact rods in each group is equal to the number of notches. The length of the multiple limiting rods on each group of impact rods and the width of the multiple notches increase sequentially along the rotation direction of the inner tube, so that the limiting rods of the same group of impact rods slide out of the arc-shaped groove from the notches at the same time.

8. The coal feeding device for a thermal power plant boiler according to claim 5, characterized in that, An annular buffer pad is fitted onto the inner tube, and the annular buffer pad is arranged opposite to the impact rod.

9. The coal feeding device for a thermal power plant boiler according to claim 4, characterized in that, A spherical impact head is fixed at one end of the impact rod near the inner tube, and the spherical impact head is made of rubber.

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