Coal feeder low-voltage ride-through power supply device with high protection performance and dust removal method of coal feeder low-voltage ride-through power supply device

Abstract

The invention discloses a high-protection coal feeder low-voltage ride-through power supply device and a dust removal method thereof.The high-protection coal feeder low-voltage ride-through power supply device comprises a low-voltage ride-through cabinet body, an inner control box, a wire groove and a switch wiring assembly, and an air inlet is formed in the lower portion of one side wall of the low-voltage ride-through cabinet body; an air outlet is formed in the upper part of the other side wall; the low-voltage crossing cabinet further comprises blowing mechanisms and an ash discharging mechanism. The blowing mechanisms are arranged on the left side and the right side of an inner cavity of the low-voltage crossing cabinet body and can blow the inner control box, the wire duct and the switch wiring assembly downwards towards the middle. And the ash discharge mechanism is arranged at the bottom plate of the low-voltage crossing cabinet main body and can open the ash discharge opening when the blowing mechanism works. According to the invention, the blowing mechanism is arranged in the cabinet body to blow and clean the fly ash in the cabinet body regularly or under the triggering condition, so that electrical faults are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply devices, and in particular to a high-protection low-voltage ride-through power supply device for a coal feeder and a dust removal method thereof. Background Art

[0002] Frequency converters (VFDs) are increasingly being used in power plants due to their precise speed regulation, fast response, and improved motor starting characteristics. Currently, coal feeders in power plants generally use VFDs as their motor speed control drive, achieving energy savings and soft-starting benefits. However, VFDs typically include protection against abnormal power supply voltage fluctuations. If the power supply voltage suddenly drops below the rated range, the DC bus voltage within the VFD drops below the operating voltage, triggering the VFD protection and halting the VFD output, causing the coal feeder's main motor to stall. Simultaneous faults and trips in multiple coal feeders can lead to passive load shedding or even unit tripping, directly impacting the power plant's production safety and the grid's operational safety. To improve the low-voltage ride-through (LVRT) capability of the coal feeder VFDs, a low-voltage ride-through (LVRT) power supply device should be connected to the VFD's DC bus to ensure continuous operation even during brief periods of low voltage.

[0003] However, the power plant workshop where the LVRT power cabinet is located is also the site of the coal feeder's operation. This nature of the work results in significant fly ash dust generation at the LVRT power cabinet's location. LVRT power cabinets operate in high-dust environments and require ventilation and heat dissipation. Dust accumulation within the cabinet can easily lead to internal electrical component failures, short circuits, and even component burnout. Although existing LVRT power cabinets are equipped with filters and cloth at both the air inlet and outlet, fine-grained fly ash particles can still enter the cabinet, attaching to and accumulating on electrical components within the cabinet, potentially affecting normal electrical operation.

[0004] In order to overcome the above problems, a highly protective low-voltage ride-through power supply device for a coal feeder and a dust removal method thereof are required. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-protection low-voltage ride-through power supply device for a coal feeder and a dust removal method thereof, which reduces electrical failures by arranging a purge mechanism in the cabinet to purge and clean the fly ash in the cabinet regularly or under triggered conditions.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a high-protection low-voltage ride-through power supply device for a coal feeder, comprising a low-voltage ride-through cabinet body, an inner control box, a wire duct and a switch wiring assembly, wherein an air inlet is provided at the lower portion of one side wall of the low-voltage ride-through cabinet body, and an air outlet is provided at the upper portion of the other side wall; the device also comprises a purge mechanism and an ash discharge mechanism, wherein the purge mechanism is arranged on the left and right sides of the inner cavity of the low-voltage ride-through cabinet body and can purge the inner control box, wire duct and switch wiring assembly downwardly toward the middle; the ash discharge mechanism is arranged at the bottom plate of the low-voltage ride-through cabinet body and can open the ash discharge opening when the purge mechanism is working.

[0008] Furthermore, the purge mechanism includes a jet assembly, and two sets of the jet assemblies are vertically arranged on the left and right sides of the inner cavity of the low-pressure crossing cabinet body respectively. The top of the jet assembly is connected to the air supply solenoid valve group that supplies clean compressed air, and the jet assembly is provided with an inward-facing and downward-facing jet nozzle.

[0009] Furthermore, the purge mechanism also includes a driving assembly; the jet assembly includes an outer jet tube and an inner air supply tube, the outer jet tube is vertically mounted on the inner side wall of the low-pressure through-cabinet body through fixed end plates at both ends, the inner air supply tube is coaxially rotatably connected to the outer jet tube, the top end of the inner air supply tube protrudes from the top opening of the outer jet tube and is connected to the air supply solenoid valve group through a rotary joint; the wall of the inner air supply tube is provided with a plurality of air outlet holes with different angular displacements from top to bottom, and the number and height of the air outlet holes and the air nozzles on the outer wall of the outer jet tube are consistent and the arrangement is one-to-one corresponding; the driving assembly drives the two inner air supply tubes to rotate synchronously.

[0010] Furthermore, the drive assembly includes a belt and a servo motor, the servo motor is installed on the inner wall of the back plate of the low-pressure through-cabinet body through a motor support, the vertical output shaft of the servo motor is installed with a driving gear, and the driving gear is engaged with a large gear at the top of the air supply inner tube; a pulley is coaxially arranged at the top of the air supply inner tube, and the belt drive is connected between the two pulleys.

[0011] Furthermore, the cantilever end of the air nozzle is tilted inward and downward, and a fan-shaped air outlet is provided at the cantilever end of the air nozzle.

[0012] Furthermore, the ash discharge mechanism includes a cylinder, a pin shaft seat 1, a pin shaft seat 2 and a bottom sealing plate. A bottom ash discharge port is provided on the bottom plate of the low-pressure crossing cabinet body. The inner side of the bottom sealing plate is connected to the edge of the bottom ash discharge port by a hinge. The bottom sealing plate can be flipped upward to close the bottom ash discharge port; the cylinder is arranged along the width direction of the low-pressure crossing cabinet body and is located in the middle position below the bottom sealing plate; the root of the cylinder is installed through the pin shaft seat 1, and the end of the piston rod of the cylinder is installed on the bottom surface of the bottom sealing plate through the pin shaft seat 2.

[0013] Furthermore, it also includes a dust sensor, which is vertically installed on the bottom sealing plate and close to the air inlet, with the sensing end of the dust sensor facing inward and upward; the dust sensor is electrically connected to the central processing unit in the inner control box.

[0014] Furthermore, it also includes a soot blowing nozzle, which is vertically installed on the top plate of the inner control box and can blow pulse compressed air into the inner control box; the soot blowing nozzle is connected to the air supply solenoid valve group that supplies clean compressed air through an air pipe.

[0015] Furthermore, the low-pressure penetration cabinet body is provided with a pipe and cable inlet at the bottom of the side wall opposite to the air inlet, and a rubber sealing sleeve is provided on the pipe and cable inlet to seal the gap between the pipeline and the opening.

[0016] The present invention also discloses a highly protective dust removal method for a low-voltage through-power supply device of a coal feeder, which utilizes the purge mechanism described in any of the above items to purge the inner cavity of the low-pressure through-power supply cabinet with clean compressed air, and at the same time opens the ash discharge opening of the ash discharge mechanism to discharge the fly ash particle impurities swept down.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] The high-protection low-voltage ride-through power supply device for a coal feeder of the present invention, by adding the purge mechanism in the main body of the low-voltage ride-through cabinet and cooperating with the purge mechanism at the bottom, can purge the main body cavity of the low-voltage ride-through cabinet regularly or when triggered and discharge fly ash from the ash discharge opening in time, thereby reducing electrical faults and safety accidents caused by fly ash accumulation.

[0019] Furthermore, by strategically placing multiple air outlets on the inner air supply tube wall, aligned with the base holes of the air nozzles, the air nozzles sequentially eject clean, dry compressed air from top to bottom as the inner air supply tube slowly rotates relative to the outer air supply tube. This creates a top-down, progressive purge, facilitating the downward and outward removal of fly ash particles. By employing a belt, pulley, and servo motor, a two-in-one system is achieved. Specifically, a synchronous toothed belt and pulley transmit power, ensuring synchronized rotation of the two inner air supply tubes, thus achieving synchronized top-down purge. The addition of two end seals between the inner air supply tube and the outer air supply tube not only seals the side gaps at both ends to prevent air leakage but also acts as an axial limiter, preventing axial movement during the inner air supply tube's rotation. By providing a fan-shaped air outlet at the cantilever end of the air nozzle, the compressed air ejected forms a fan-shaped surface, increasing the purge area and ensuring a complete, clean purge. A pneumatic cylinder actuates the opening and closing of the bottom seal, ensuring quick and reliable operation. The mounting plate for the pin seat also supports the cabinet body. A dust sensor is installed on the bottom seal, ensuring that fly ash entering from the air inlet is most likely to accumulate near the point of entry. This sensor can detect when fly ash accumulation exceeds maintenance standards and trigger a purge. A sootblower nozzle is installed on the top plate of the inner control box, enabling dust removal from the inner control box cavity before the purge, preventing the risk of fly ash re-entering the inner control box cavity. Pipe and cable inlets are provided at the bottom of the side wall of the low-pressure cross-section cabinet body, eliminating the need for pre-recorded holes in the bottom plate and facilitating sealing. A rubber seal is installed on the cable inlet to seal the gap between the pipe and the opening, minimizing the risk of fly ash entering this area.

[0020] The highly protective dust removal method for the low-voltage through-power supply device of the coal feeder of the present invention removes dust from the inner cavity of the low-voltage through-power supply cabinet body by blowing and discharging dust at the same time, effectively cleaning the inner cavity of the low-voltage through-power supply cabinet body and ensuring the safe operation of electrical components in a high-dust environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is the electrical schematic diagram of the high-protection low-voltage ride-through power supply device for the coal feeder of the present invention;

[0023] Figure 2 This is a schematic diagram of the main view of the high-protection low-voltage ride-through power supply device for a coal feeder according to the present invention;

[0024] Figure 3 This is a schematic cross-sectional view of a high-protection low-voltage ride-through power supply device for a coal feeder according to the present invention;

[0025] Figure 4This is a schematic diagram of the main view of the purge mechanism in the present invention;

[0026] Figure 5 This is a schematic diagram of the main view of the air supply inner tube in the present invention;

[0027] Figure 6 It is a side cross-sectional schematic diagram of the ash discharge port portion of the bottom of the present invention.

[0028] Explanation of the accompanying symbols: 1. Low-pressure penetration cabinet body; 101. Pipe and cable inlet; 102. Air inlet; 103. Air outlet; 104. Cabinet foot plate; 105. Bottom dust outlet; 2. Internal control box; 3. Wire trough; 4. Switch wiring assembly; 5. Cooling fan; 6. Indicator assembly; 7. Jet outer pipe; 701. Fixed end plate; 702. Jet nozzle; 8. Air supply inner pipe; 801. Pulley; 802. Large gear; 803. Rotary joint; 804. Air outlet; 805. End sealing ring; 9. Belt; 10. Servo motor; 11. Cylinder; 12. Pin seat one; 13. Pin seat two; 14. Bottom sealing plate; 15. Dust sensor; 16. Soot blowing nozzle. DETAILED DESCRIPTION

[0029] The core of the present invention is to provide a highly protective low-voltage ride-through power supply device for a coal feeder and a dust removal method thereof. By arranging a purge mechanism in the cabinet to purge and clean the fly ash in the cabinet regularly or when triggered, electrical failures are reduced.

[0030] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0032] With reference to the accompanying drawings, Figure 1 This is the electrical schematic diagram of the high-protection low-voltage ride-through power supply device for the coal feeder of the present invention; Figure 2 This is a schematic diagram of the main view of the high-protection low-voltage ride-through power supply device for a coal feeder according to the present invention; Figure 3 This is a schematic cross-sectional view of a high-protection low-voltage ride-through power supply device for a coal feeder according to the present invention; Figure 4This is a schematic diagram of the main view of the purge mechanism in the present invention; Figure 5 This is a schematic diagram of the main view of the air supply inner tube in the present invention; Figure 6 It is a side cross-sectional schematic diagram of the ash discharge port portion of the bottom of the present invention.

[0033] In one embodiment, Figures 1 to 6 As shown in FIG, the high-protection low-voltage ride-through power supply device for coal feeder of the present invention comprises a low-voltage ride-through cabinet body 1, an inner control box 2, a wire duct 3 and a switch wiring assembly 4, wherein the inner control box 2 is provided with a main control electrical module. Figure 1 As shown, the electrical principles are essentially the same as those used in existing technologies: the central processing unit (CPU), utilizing a high-performance 16-bit DSP digital signal processor, performs cyclic monitoring of system voltage and current. Upon detecting a drop in system voltage to a set value, the CPU outputs a PWM control variable to drive the IGBT module. This instantly boosts the DC voltage rectified by the rectifier and filter units through the power unit, outputting 500V DC power to the inverter's DC bus to maintain normal operation. Once the grid voltage stabilizes, the device automatically switches from operating to standby mode, with the inverter still powered by the AC bus.

[0034] Regarding the air-cooling structure of the LPRT cabinet body 1: an air inlet 102 is provided at the lower portion of one side wall of the LPRT cabinet body 1, and an air outlet 103 is provided at the upper portion of the other side wall. A cooling fan 5 is mounted inside the air outlet 103 to draw in air. Filters and cloths are installed on the air inlet 102 and outlet 103 to prevent dust. However, to ensure sufficient airflow, the filters and cloths cannot be too dense. As a result, tiny fly ash particles can become trapped and gradually accumulate within the cavity of the LPRT cabinet body 1 as they flow through it.

[0035] The present invention's highly protective low-voltage ride-through power supply unit for coal feeders features a significant innovation compared to existing technologies: it also includes a purge mechanism and an ash removal mechanism. The purge mechanisms are located on either side of the interior of the low-voltage ride-through cabinet body 1 and are capable of sweeping downward from the center of the cabinet body 1, away from the inner control box 2, wire duct 3, and switch wiring assembly 4. The ash removal mechanism is located on the bottom plate of the low-voltage ride-through cabinet body 1 and is capable of opening an ash removal opening when the purge mechanism is in operation. The actuators for both the purge and ash removal mechanisms are electrically connected to the central processing unit within the inner control box 2.

[0036] By adding the purge mechanism in the low-pressure ride-through cabinet body 1 and coordinating the purge mechanism at the bottom, the cavity of the low-pressure ride-through cabinet body 1 can be purged regularly or when triggered, and fly ash can be discharged from the ash discharge opening in time, thereby reducing electrical failures and safety accidents caused by fly ash accumulation.

[0037] In one embodiment of the present invention, Figure 3As shown, the purge mechanism includes two jet assemblies, one vertically positioned on the left and right sides of the interior of the low-pressure feed cabinet body 1. The top ends of the jet assemblies are connected to a solenoid valve assembly that supplies clean compressed air. Each jet assembly is equipped with an inward-facing and downward-facing jet nozzle 702. The solenoid valve assembly is electrically connected to the central processing unit.

[0038] Specifically, if Figures 3-5 As shown, the purge mechanism also includes a drive assembly. The jet assembly comprises an outer jet tube 7 and an inner air supply tube 8. The outer jet tube 7 is vertically mounted on the inner side wall of the low-pressure through-hole cabinet body 1 via fixed end plates 701 at both ends. The inner air supply tube 8 is coaxially and rotatably connected to the outer jet tube 7. The bottom end of the inner air supply tube 8 is sealed, and the top end of the inner air supply tube 8 protrudes from the top opening of the outer jet tube 7 and is connected to the air supply solenoid valve assembly via a rotary joint 803. It should be noted that the wall of the inner air supply tube 8 is provided with multiple air outlet holes 804 with different angular displacements from top to bottom. That is, within a 360-degree circumference, all air outlet holes 804 are arranged at equal angular displacements, and the angle between adjacent air outlet holes 804 is equal. The air outlet holes 804 and the air nozzles 702 on the outer wall of the outer jet tube 7 are identical in number and height, and are arranged in a one-to-one correspondence. The drive assembly drives the two inner air supply tubes 8 to rotate synchronously.

[0039] By reasonably arranging multiple air outlet holes 804 on the wall of the inner air supply tube 8, and correspondingly arranging the air outlet holes 804 and the root air holes of the air nozzles 702, it is possible to achieve that during the slow rotation of the inner air supply tube 8 relative to the outer air injection tube 7, the air nozzles 702 from top to bottom sequentially eject clean and dry compressed air outward, that is, a gradual purge from top to bottom is realized, which is conducive to lifting the fly ash particles and discharging them downward and outward.

[0040] Specifically, if Figures 3-5 As shown, the drive assembly includes a belt 9 and a servo motor 10. The servo motor 10 is mounted on the inner wall of the back panel of the low-voltage transmission cabinet body 1 via a motor support. The vertical output shaft of the servo motor 10 is mounted with a driving gear, which meshes with a large gear 802 at the top of an inner air supply tube 8. A pulley 801 is coaxially arranged at the top of the inner air supply tube 8, and the belt 9 is connected between the two pulleys 801. The control cable of the servo motor 10 is connected to the central processing unit.

[0041] Specifically, if Figure 4 As shown, the belt 9 and the pulley 801 specifically use a synchronous toothed belt and a synchronous pulley to transmit power.

[0042] By adopting the belt 9, the pulley 801 and the servo motor 10, one-to-two is achieved. At the same time, the synchronous toothed belt and synchronous pulley are used to transmit power, which can ensure that the two air supply inner tubes 8 rotate synchronously, thereby realizing synchronous purging from top to bottom.

[0043] Specifically, if Figure 5 As shown, both ends of the outer wall where the air supply inner tube 8 and the air injection outer tube 7 overlap are provided with sealing grooves and end sealing rings 805 are installed. Correspondingly, the inner wall of the air injection outer tube 7 is also provided with a concave ring groove at the installation position of the end sealing ring 805.

[0044] By adding two end sealing rings 805 between the air supply inner tube 8 and the air injection outer tube 7, not only can the side gaps at both ends be sealed to prevent air leakage, but on the other hand, they can also play an axial limit role to avoid axial stringing during the rotation of the air supply inner tube 8.

[0045] Specifically, if Figure 4 As shown, the cantilever end of the air nozzle 702 is tilted inward and downward, and a fan-shaped air outlet is provided at the cantilever end of the air nozzle 702, and the compressed air blown out is a fan-shaped surface.

[0046] By arranging a fan-shaped air outlet at the cantilever end of the air nozzle 702, the compressed air blown out is a fan-shaped surface, which can increase the blowing area and ensure blowing and cleaning without dead angles.

[0047] In one embodiment of the present invention, Figure 2 、 Figure 3 and Figure 6 As shown, the ash discharge mechanism includes a cylinder 11, a pin holder 12, a pin holder 2 13, and a bottom sealing plate 14. A bottom ash discharge opening 105 is provided on the bottom plate of the low-pressure run-through cabinet body 1. The inner side of the bottom sealing plate 14 is hingedly connected to the edge of the bottom ash discharge opening 105. The front edge of the bottom sealing plate 14 can be flipped upward to close the bottom ash discharge opening 105. Specifically, a sealing gasket is adhered to the top surface of the bottom sealing plate 14, which seals the gap between the bottom sealing plate 14 and the bottom sealing plate 14 when the bottom sealing plate 14 is tightened. The cylinder 11 is arranged along the width of the low-pressure run-through cabinet body 1 and is located in the middle below the bottom sealing plate 14. The base of the cylinder 11 is mounted via pin holder 12, and the top of the mounting plate of pin holder 12 is fixedly connected to the bottom of the back panel of the low-pressure run-through cabinet body 1. The mounting plate of pin holder 12 also assists the cabinet foot plate 104 in supporting the cabinet body. The piston rod end of the cylinder 11 is mounted on the bottom surface of the bottom sealing plate 14 via pin holder 2 13. A solenoid valve is provided on the air supply line of the cylinder 11, and the electric control cable end of the solenoid valve is connected to the central processing unit. The opening between the front edge of the bottom sealing plate 14 and the front edge of the bottom ash discharge port 105 is the ash discharge opening.

[0048] By adopting the cylinder 11 to drive the opening and closing of the bottom sealing plate 14, the action is fast and reliable; at the same time, the mounting plate of the pin shaft seat 12 also assists the cabinet foot plate 104 to support the cabinet body.

[0049] Specifically, if Figure 2 、 Figure 3 and Figure 6As shown, the highly secure low-voltage ride-through power supply device for a coal feeder of the present invention further includes a dust sensor 15 . Dust sensor 15 is vertically mounted on bottom seal plate 14 near air inlet 102 , with the sensing end of dust sensor 15 facing inward and upward. Dust sensor 15 is electrically connected to the central processing unit within inner control box 2 .

[0050] Specifically, dust sensor 15 utilizes a photoresistor or photodiode. When the light emitted by the light-emitting diode is blocked by fly ash, dust sensor 15 feeds back a signal to the central processing unit. Dust sensor 15 can also utilize a dust accumulation sensor based on the light scattering principle, employing a light scattering method for monitoring, which is particularly suitable for online monitoring of dust pollution ratios.

[0051] By adding a dust sensor 15 on the bottom sealing plate 14, the fly ash entering from the air inlet 102 is most likely to accumulate at the position where it just enters. The signal that the fly ash accumulation exceeds the maintenance standard can be collected in time to trigger the blowing and dust removal.

[0052] In one embodiment of the present invention, Figure 3 As shown, the high-protection coal feeder low-voltage ride-through power supply device of the present invention also includes a soot blowing nozzle 16, which is vertically installed on the top plate of the inner control box 2. The soot blowing nozzle 16 can blow pulsed compressed air into the inner control box 2.

[0053] Specifically, if Figure 3 As shown, the sootblowing nozzles 16 are connected via air pipes to a solenoid valve assembly that supplies clean compressed air. There are two sootblowing nozzles 16, symmetrically located at either end of the top plate of the inner control box 2. The compressed air from the sootblowing nozzles 16 is discharged through the cable inlet and outlet slots on the bottom plate of the inner control box 2.

[0054] By adding a soot blowing nozzle 16 on the top plate of the inner control box 2, the inner cavity of the inner control box 2 can be ash-discharged before the blowing operation, thereby avoiding the risk of flying fly ash entering the inner cavity of the inner control box 2 again.

[0055] In one embodiment of the present invention, Figure 2 and Figure 3 As shown, the low-pressure penetration cabinet body 1 is provided with a pipe and cable inlet 101 at the bottom of the side wall opposite to the air inlet 102. A rubber sealing sleeve is provided on the pipe and cable inlet 101 to seal the gap between the pipeline and the opening.

[0056] By providing a pipe and cable inlet 101 at the bottom of the side wall of the low-voltage through-type cabinet body 1, the need for pre-reserved holes in the bottom plate is avoided, facilitating sealing. By providing a rubber sealing sleeve on the cable inlet 101, the gap between the pipe and the opening can be sealed, reducing the risk of fly ash entering this area.

[0057] In summary, the highly protective low-voltage ride-through power supply device for coal feeders of the present invention, by adding the aforementioned purge mechanism within the low-voltage ride-through cabinet body 1 and cooperating with the purge mechanism at the bottom, can periodically or upon triggering purge the cavity of the low-voltage ride-through cabinet body 1 and promptly discharge fly ash from the ash discharge opening, thereby reducing electrical faults and safety accidents caused by fly ash accumulation. Furthermore, by rationally disposing multiple air outlet holes 804 on the wall of the inner air supply tube 8, which correspond to the air outlet holes at the base of the air nozzles 702, the air nozzles 702 sequentially eject clean, dry compressed air from top to bottom during the slow rotation of the inner air supply tube 8 relative to the outer air supply tube 7. This achieves a top-down, step-by-step purge, facilitating the downward and outward discharge of fly ash particles. By employing a belt 9, a pulley 801, and a servo motor 10, a one-to-two system is achieved. Furthermore, the use of a synchronous toothed belt and pulleys to transmit power ensures the synchronous rotation of the two inner air supply tubes 8, thereby achieving synchronous top-down purge. By adding two end sealing rings 805 between the inner air supply tube 8 and the outer air jet tube 7, not only can the side gaps at both ends be sealed to prevent air leakage, but they can also act as axial limiters to avoid axial movement during the rotation of the inner air supply tube 8. By providing a fan-shaped air outlet at the cantilever end of the air nozzle 702, the compressed air blown out is a fan-shaped surface, which can increase the purge area and ensure that there is no dead angle purge cleaning. By using the cylinder 11 to drive the opening and closing of the bottom sealing plate 14, the operation is fast and reliable; at the same time, the mounting plate of the pin shaft seat 12 also assists the cabinet foot plate 104 in supporting the cabinet body. By adding a dust sensor 15 to the bottom sealing plate 14, the fly ash entering from the air inlet 102 is most likely to accumulate at the position where it first enters. The signal that the fly ash accumulation exceeds the maintenance standard can be collected in time to trigger the purge and dust removal. By adding a sootblowing nozzle 16 to the top plate of the inner control box 2, the inner chamber of the inner control box 2 can be purged before the purge operation, preventing the risk of fly ash re-entering the inner chamber of the inner control box 2. By providing a pipe and cable inlet 101 at the bottom of the side wall of the low-pressure cross-connect cabinet body 1, the need for pre-reserved holes in the bottom plate is avoided, facilitating sealing. A rubber sealing sleeve is provided on the cable inlet 101 to seal the gap between the pipeline and the opening, reducing the risk of fly ash entering this area.

[0058] The present invention also discloses a highly protective dust removal method for a low-voltage ride-through power supply device of a coal feeder, which uses the purge mechanism in any of the above embodiments to purge the inner cavity of the low-voltage ride-through cabinet body 1 with clean compressed air, and at the same time opens the ash discharge opening of the ash discharge mechanism to discharge the fly ash particle impurities swept down.

[0059] The inner cavity of the low-voltage through-going cabinet body 1 is dust-removed by blowing and exhausting dust at the same time, thereby effectively cleaning the inner cavity of the low-voltage through-going cabinet body 1 and ensuring the safe operation of electrical components in a high-dust environment.

[0060] The highly protective dust removal method for a low-voltage ride-through power supply device of a coal feeder of the present invention comprises the following steps:

[0061] Step 1: In standby mode, the cooling fan 5 operates, introducing flowing air to cool the cavity of the low-pressure cross-connect cabinet body 1. The central processing unit cyclically scans the status of the input port, including the power supply side system voltage and the input of the dust sensor 15, and operates in standby mode according to the set program.

[0062] Step 2: Purge and dust removal. When the set time period is reached or the dust sensor 15 transmits a signal indicating that the fly ash accumulation exceeds the standard, the central processing unit controls the operation of the purge mechanism and the ash removal mechanism.

[0063] The air supply solenoid valve group that controls the soot blowing nozzle 16 is repeatedly opened and closed according to the set time interval. The soot blowing nozzle 16 blows out clean compressed air at the top of the inner control box 2. The pulsed compressed air is discharged from the strip holes of the inlet and outlet cables at the bottom plate of the inner control box 2, and the fly ash particle impurities that have penetrated into the inner side of the inner control box 2 are discharged.

[0064] The air supply solenoid valve assembly connected to rotary joint 803 is controlled to open, allowing clean compressed air to enter the air supply inner tube 8 through rotary joint 803 and be ejected through air nozzle 702 through air outlet 804. The fan-shaped airflow sweeps the low-pressure interior of the cabinet body 1 diagonally downward. At the same time, the servo motor 10 is controlled to start, driving the air supply inner tube 8 to rotate via the driving gear and large gear 802. The air supply inner tube 8 then drives the other air supply inner tube 8 to rotate synchronously via pulley 801 and belt 9. As the air supply inner tube 8 slowly rotates relative to the air outlet outer tube 7, the air nozzles 702 from top to bottom sequentially connect with the corresponding air outlet 804, ejecting clean, dry compressed air outward. This achieves a gradual top-down purge, which helps to lift and discharge fly ash particles downward and outward.

[0065] The solenoid valve provided on the air supply pipeline of the control cylinder 11 is actuated, the cylinder 11 contracts, and the pin shaft seat 13 is pulled, so that the ash discharge opening between the front edge of the bottom sealing plate 14 and the front edge of the bottom ash discharge port 105 is opened, and the fly ash particles blown down by the ash blowing nozzle 16 and the air nozzle 702 pass through the ash discharge opening.

[0066] Step 3: Reset. When the set operating time is reached, the air supply solenoid valve assembly of the sootblowing nozzle 16 is controlled to close. The air supply inner tube 8 rotates to its initial position, controlling the servo motor 10 to stop and controlling the air supply solenoid valve assembly connected to the rotary joint 803 to close. The solenoid valve installed on the air supply pipeline of the cylinder 11 is controlled to operate, causing the cylinder 11 to push out and the front edge of the bottom sealing plate 14 to flip upward, effectively sealing the bottom ash discharge port 105. Due to the purge cleaning of the bottom air nozzle 702, the dust on the dust sensor 15 is effectively cleared, and the dust sensor 15 signal is reset.

[0067] The corresponding air outlet holes 804 are connected in sequence from top to bottom through the air nozzle 702, and clean and dry compressed air is ejected outward, that is, a gradual blowing from top to bottom is realized, which is conducive to lifting the fly ash particles and discharging them downward and outward; the soot blowing nozzle 16 pulses the inner cavity of the inner control box 2, so that the inner cavity of the inner control box 2 is effectively dust-removed to avoid becoming a dead corner for dust removal.

[0068] In a specific embodiment of the present invention, in the above-mentioned step 2, during the operation of the purge mechanism and the dust removal mechanism, if the detection unit detects that the voltage of the power supply system suddenly drops, the central processing unit suspends the operation of the purge mechanism and the dust removal mechanism and immediately enters the low-voltage ride-through working state to ensure continuous operation of the inverter.

[0069] By reasonably setting the priority of low-pressure ride-through work, it is ensured that the device can quickly enter the low-pressure ride-through working state in any state, ensuring the safe operation of the coal feeder.

[0070] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0071] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A high-protection low-voltage ride-through power supply device for a coal feeder, comprising a low-voltage ride-through cabinet body (1), an internal control box (2), a wire duct (3), and a switch wiring assembly (4), wherein an air inlet (102) is provided at the lower portion of one side wall of the low-voltage ride-through cabinet body (1), and an air outlet (103) is provided at the upper portion of the other side wall; characterized in that: It also includes a purge mechanism and an ash discharge mechanism, wherein the purge mechanism is arranged on the left and right sides of the inner cavity of the low-pressure passage cabinet body (1) and is capable of blowing the inner control box (2), the wire duct (3) and the switch wiring assembly (4) downward toward the middle; the ash discharge mechanism is arranged at the bottom plate of the low-pressure passage cabinet body (1) and is capable of opening an ash discharge opening when the purge mechanism is in operation.

2. The high-protection low-voltage ride-through power supply device for coal feeder according to claim 1 is characterized in that: The purge mechanism includes a jet assembly, two sets of which are vertically arranged on the left and right sides of the inner cavity of the low-pressure passage cabinet body (1), respectively. The top of the jet assembly is connected to an air supply solenoid valve group that supplies clean compressed air, and the jet assembly is provided with an inward-facing and downward-facing jet nozzle (702).

3. The high-protection low-voltage ride-through power supply device for coal feeder according to claim 2, characterized in that: The purge mechanism further includes a drive assembly; the jet assembly includes an outer jet tube (7) and an inner air supply tube (8); the outer jet tube (7) is vertically mounted on the inner side wall of the low-pressure through-type cabinet body (1) through fixed end plates (701) at both ends; the inner air supply tube (8) is coaxially rotatably connected to the outer jet tube (7); the top end of the inner air supply tube (8) protrudes from the top of the outer jet tube (7) and is connected to the air supply solenoid valve group through a rotary joint (803); a plurality of air outlet holes (804) with different angular displacements are opened from top to bottom on the wall of the inner air supply tube (8); the number of the air outlet holes (804) and the air nozzles (702) on the outer wall of the outer jet tube (7) are the same, the height is the same, and they are arranged in a one-to-one correspondence; the drive assembly drives the two inner air supply tubes (8) to rotate synchronously.

4. The high-protection low-voltage ride-through power supply device for coal feeder according to claim 3, characterized in that: The driving assembly comprises a belt (9) and a servo motor (10), wherein the servo motor (10) is mounted on the inner wall of the back plate of the low-pressure through-type cabinet body (1) via a motor support, and a driving gear is mounted on the vertical output shaft of the servo motor (10), and the driving gear is engaged with a large gear (802) at the top end of the air supply inner tube (8); a pulley (801) is coaxially arranged at the top end of the air supply inner tube (8), and the belt (9) is connected between the two pulleys (801) in a transmission manner.

5. The high-protection low-voltage ride-through power supply device for a coal feeder according to any one of claims 2 to 4, characterized in that: The cantilever end of the air nozzle (702) is tilted inward and downward, and a fan-shaped air outlet is provided at the cantilever end of the air nozzle (702).

6. The high-protection low-voltage ride-through power supply device for coal feeder according to claim 1 is characterized in that: The ash discharge mechanism comprises a cylinder (11), a pin shaft seat 1 (12), a pin shaft seat 2 (13) and a bottom sealing plate (14); a bottom ash discharge port (105) is provided on the bottom plate of the low-pressure crossing cabinet body (1); the inner side of the bottom sealing plate (14) is connected to the edge of the bottom ash discharge port (105) through a hinge; the bottom sealing plate (14) can be turned upward to close the bottom ash discharge port (105); the cylinder (11) is arranged along the width direction of the low-pressure crossing cabinet body (1) and is located in the middle position below the bottom sealing plate (14); the root of the cylinder (11) is installed through the pin shaft seat 1 (12), and the end of the piston rod of the cylinder (11) is installed on the bottom surface of the bottom sealing plate (14) through the pin shaft seat 2 (13).

7. The high-protection low-voltage ride-through power supply device for coal feeder according to claim 6, characterized in that: The invention also includes a dust sensor (15), which is vertically mounted on the bottom sealing plate (14) and close to the air inlet (102), with the sensing end of the dust sensor (15) facing inward and upward; the dust sensor (15) is electrically connected to the central processing unit in the inner control box (2).

8. The high-protection low-voltage ride-through power supply device for coal feeder according to claim 1, characterized in that: The soot blowing nozzle (16) is vertically mounted on the top plate of the inner control box (2), and the soot blowing nozzle (16) is capable of blowing pulse compressed air into the inner control box (2); the soot blowing nozzle (16) is connected to an air supply solenoid valve group that supplies clean compressed air through an air pipe.

9. The high-protection low-voltage ride-through power supply device for coal feeder according to claim 1, characterized in that: The low-pressure through-the-wall cabinet body (1) is provided with a pipe and cable inlet (101) at the bottom of the side wall opposite to the air inlet (102), and a rubber sealing sleeve is provided on the pipe and cable inlet (101) to seal the gap between the pipeline and the opening.

10. A highly protective method for removing dust from a low-voltage through-the-line power supply device for a coal feeder, characterized in that: The purging mechanism according to any one of claims 1 to 9 is used to purge the inner cavity of the low-pressure through-the-box body (1) with clean compressed air, and at the same time, the ash discharge opening of the ash discharge mechanism is opened to discharge the fly ash particle impurities swept down.

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