Permanent magnetic suspension shaftless low-noise efficient axial flow fan for thermal power plant

Abstract

The invention discloses a permanent magnetic suspension shaftless low-noise high-efficiency axial flow fan for a thermal power plant, and relates to the technical field of magnetic suspension fans, the permanent magnetic suspension shaftless low-noise high-efficiency axial flow fan comprises a cold air island, a machine body fixedly mounted at the bottom of the cold air island through a bracket, and an impeller rotationally mounted in the machine body, a magnetic ring is fixedly installed on the side wall of the impeller through a sealing ring, an annular cavity matched with the magnetic ring is formed in the side wall of the machine body, permanent magnets matched with the magnetic ring are fixedly installed on the upper side wall and the lower side wall of the annular cavity, and a magnetic force adjusting assembly matched with the magnetic ring is further installed in the annular cavity. The dust removal device has the beneficial effects that when the impeller works, the stress of the impeller can be automatically balanced through magnetic force changes and air pressure changes of the outlet end of the machine body, the operation stability of the impeller is improved, and meanwhile when the air pressure of the outlet end of the machine body changes, dust removal treatment in the machine body can be automatically achieved through airflow changes; and the overall operation stability is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation fans, and particularly to a permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants. Background Art

[0002] In the field of thermal power generation, axial flow fans, as the core equipment of air-cooled island cooling, boiler ventilation and other systems, their performance directly affects the energy consumption and operation stability of thermal power plants. Traditional axial flow fans generally adopt mechanical bearings and drive shaft structures, which have problems such as large frictional losses, high vibration and noise, and high maintenance costs.

[0003] In recent years, the application of magnetic levitation technology has significantly improved the efficiency of fans. However, existing magnetic levitation axial flow fans still face many challenges. When the pipeline resistance suddenly changes (such as the resistance increases due to fouling of condenser fins), the fan needs to output a higher wind pressure to maintain the flow rate. The resulting aerodynamic load is likely to cause unexpected lateral displacement of the magnetic levitation impeller, which not only affects the dynamic balance of the impeller but also may cause rubbing against the casing. Moreover, there is a lack of an adaptive adjustment mechanism for pressure overload caused by abnormal flow. When the system flow rate surges or the pipeline is blocked, the outlet pressure of the fan rises suddenly, which is likely to cause motor overload, component damage, and even safety accidents. Therefore, it is urgent to develop a permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants, which solves the problems raised in the above background art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants, including a cold air island. The bottom of the cold air island is fixedly installed with a machine body through a bracket, and further includes: An impeller, which is rotatably installed in the machine body. A magnetic ring is fixedly installed on the side wall of the impeller through a sealing ring. An annular cavity matching with the magnetic ring is opened on the side wall of the machine body. Permanent magnets matching with the magnetic ring are fixedly installed on both the upper and lower side walls of the annular cavity. A magnetic force adjusting component matching with the magnetic ring is also installed in the annular cavity. The magnetic force adjusting component is used to adjust the magnitudes of the magnetic forces received on both sides of the magnetic ring, and further adjust the position of the impeller in the machine body; A pressure relief part, which includes a plurality of pressure relief holes opened near the outlet end of the machine body. A moving cavity communicating with the plurality of pressure relief holes is opened in the machine body, and a counterpoint ring is slidably installed in the moving cavity. Counterpoint holes matching with the plurality of pressure relief holes are opened on the counterpoint ring. A triggering component matching with the counterpoint ring is installed between the annular cavity and the moving cavity; The diversion part includes a gas guide ring fixedly installed on the machine body, and the gas guide ring communicates with a plurality of pressure relief holes. A plurality of exhaust pipes are connected between the gas guide ring and the air outlet end of the machine body.

[0006] Furthermore, a fixing ring is fixedly installed on the side wall of the magnetic ring. The height of the annular cavity is less than the height of the sealing ring, and the thickness of the fixing ring is less than the thickness of the magnetic ring.

[0007] Furthermore, the magnetic force adjusting assembly is composed of a displacement sensor and two magnetic force coils. The displacement sensor is fixedly installed in the annular cavity and corresponds to the position of the fixing ring. The two magnetic force coils are respectively fixedly installed at both ends of the annular cavity and correspond to both ends of the magnetic ring respectively. The displacement sensor is signal-connected to the two magnetic force coils.

[0008] Furthermore, the triggering assembly is composed of a moving ring and a plurality of connecting rods. The moving ring is slidably installed on one side of the annular cavity close to the outlet end of the machine body. The plurality of connecting rods are fixedly installed between the moving ring and the alignment ring. A through groove corresponding to the position of the displacement sensor is opened on the moving ring. A plurality of springs are installed between the alignment ring and the moving cavity.

[0009] Furthermore, an annular groove is opened on the inner wall of the machine body far from the outlet end, and a rotating ring is hermetically and rotatably installed in the annular groove. A scraping ring fitting the inner wall of the machine body is fixedly installed on the inner wall of the rotating ring. A fixed gear ring is fixedly installed on the side wall of the rotating ring. A driving assembly matching the fixed gear ring is installed on the gas guide ring.

[0010] Furthermore, the driving assembly is composed of a fixed gear, a rotating rod, a connecting gear, a driving gear, a driving fan blade and a driving gear ring. The fixed gear is rotatably installed on the side wall of the machine body through a rotating shaft and meshes with the fixed gear ring. The rotating rod is rotatably installed on the side wall of the machine body. The connecting gear is fixedly installed on the rotating rod and meshes with the fixed gear. The driving fan blade is hermetically and rotatably installed in the gas guide ring. The driving gear ring is fixedly installed on the side wall of the driving fan blade. The driving gear is fixedly installed at the other end of the rotating rod and meshes with the driving gear ring.

[0011] Furthermore, a support block is fixedly installed on the side wall of the machine body and is rotationally connected to the rotating rod. A fixed block is also fixedly installed on the side wall of the machine body and is rotationally connected to the rotating shaft. The rotating shaft is fixedly connected to the fixed gear.

[0012] Further, the driving fan blade is composed of an inner ring, an outer ring and a plurality of fan blades. The inner ring and the outer ring are both sealed and rotatably installed at one end of the air guide ring far from the exhaust pipe, and the inner ring and the outer ring are staggered with the positions of a plurality of pressure relief holes. A plurality of the fan blades are fixedly installed between the inner ring and the outer ring, and the fan blades correspond to the positions of the pressure relief holes. The driving gear ring is fixedly installed on the side wall of the outer ring, and the driving gear ring is in sealed and rotatable connection with the air guide ring.

[0013] Compared with the existing technology, the advantages of the present invention are as follows: 1: Through the cooperation of the magnetic force adjustment component and the permanent magnet, the force on the impeller can be automatically balanced during the rotation of the impeller, so that its position can be kept stable in the machine body, and the overall operation stability can be improved.

[0014] 2: Through the cooperation of the driving component and the pressure relief holes, when the position of the impeller deviates due to air pressure changes, the air outlet end of the machine body can be automatically relieved of pressure, avoiding damage caused by excessive movement of the impeller and realizing adaptive adjustment.

[0015] 3: Through the cooperation of the diversion part and the driving component, when the air outlet end of the machine body is relieved of pressure, the discharged air flow can be used to provide a driving effect for the rotation of the rotating ring, so that the scraping ring can clean the inside of the machine body, improve the internal hygiene degree of the machine body, reduce the adverse influence of dust accumulation on the air flow in the machine body operation, and further improve the overall operation stability.

[0016] In summary, the present invention can automatically balance the force on the impeller by using magnetic force changes and air pressure changes at the air outlet end of the machine body during the operation of the impeller, improve the operation stability of the impeller, and at the same time, when the air pressure at the air outlet end of the machine body changes, it can also automatically clean the inside of the machine body by using air flow changes, further improving the overall operation stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. is a schematic structural diagram of a permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for a thermal power plant proposed by the present invention; Figure 2 is Figure 2 a schematic structural diagram from another perspective; Figure 3 is Figure 1 an enlarged schematic diagram of the structure at the machine body in FIG. Figure 4 is Figure 3 a schematic diagram of the structure at the machine body in FIG. Figure 5 is Figure 3 a schematic diagram of the internal structure of the machine body in FIG. Figure 6 is Figure 5 another perspective schematic diagram of the structure at the impeller in FIG. Figure 7 Another perspective schematic diagram of the structure at the driving gear ring in Figure 4 ; Figure 8 is Figure 3 the front view of Figure 9 is Figure 8 the schematic diagram of the structure of the A-A plane in Figure 10 is Figure 9 the enlarged schematic diagram of the structure of part a in Figure 11 is Figure 9 the enlarged schematic diagram of the structure of part b in

[0018] In the figure: 1, cold air island; 2, bracket; 3, body; 4, impeller; 5, annular cavity; 6, sealing ring; 7, magnetic ring; 8, permanent magnet; 9, magnetic coil; 10, displacement sensor; 11, fixed ring; 12, moving ring; 13, pressure relief hole; 14, moving cavity; 15, alignment ring; 16, alignment hole; 17, spring; 18, connecting rod; 19, air guide ring; 20, exhaust pipe; 21, rotating ring; 22, scraping ring; 23, fixed gear ring; 24, fixed gear; 25, support block; 26, rotating rod; 27, connecting gear; 28, driving gear; 29, driving fan blade; 30, driving gear ring. Specific implementation manner

[0019] Referring to Figures 1 - 11 , a permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants includes a cold air island 1. The bottom of the cold air island 1 is fixedly installed with a body 3 through a bracket 2. The installation between the cold air island 1 and the body 3 adopts the existing induced draft installation method. When the body 3 operates, air is made to flow through the condenser fin tube bundle on the cold air island 1 to take away the heat released by the condensation of steam in the tube bundle, realizing the cooling treatment. It also includes an impeller 4. The impeller 4 is rotatably installed in the body 3. A motor is installed in the body 3. The output end of the motor is connected to the impeller 4 through a magnetic levitation bearing, which is used to suspend and support the impeller 4 and provide drive for the operation of the impeller 4 when the motor works. The magnetic levitation installation method is an existing technology, and its working principle and specific structure are not elaborated here.

[0020] A magnetic ring 7 is fixedly installed on the side wall of the impeller 4 through a sealing ring 6. An annular cavity 5 matching with the magnetic ring 7 is formed on the side wall of the body 3. Permanent magnets 8 matching with the magnetic ring 7 are fixedly installed on the upper and lower side walls of the annular cavity 5. The two permanent magnets 8 have the same magnetic poles as the corresponding sides of the magnetic ring 7, thus applying a repulsive force to the magnetic ring 7 to make it suspended in the body 3, avoiding direct contact between the magnetic ring 7 on the impeller 4 and the annular cavity 5. A fixing ring 11 is fixedly installed on the side wall of the magnetic ring 7. The height of the annular cavity 5 is less than the height of the sealing ring 6, and the thickness of the fixing ring 11 is less than the thickness of the magnetic ring 7. The design of the sealing ring 6 can prevent some gas from entering the annular cavity 5 during the operation of the impeller 4, avoiding the problem that the change of the gas flow direction causes the impeller 4 to surge.

[0021] A magnetic force adjusting component matching with the magnetic ring 7 is also installed in the annular cavity 5. The magnetic force adjusting component is used to adjust the magnetic force on both sides of the magnetic ring 7, and further adjust the position of the impeller 4 in the body 3. The magnetic force adjusting component consists of a displacement sensor 10 and two magnetic force coils 9. The displacement sensor 10 is fixedly installed in the annular cavity 5 and corresponds to the position of the fixing ring 11. The two magnetic force coils 9 are respectively fixedly installed at both ends of the annular cavity 5 and correspond to both ends of the magnetic ring 7. The displacement sensor 10 is signal-connected to the two magnetic force coils 9. The displacement sensor 10 can monitor the position of the fixing ring 11 on the impeller 4 in the annular cavity 5 in real time. When the fixing ring 11 moves in the annular cavity 5, the displacement sensor 10 controls the current passing through the two magnetic force coils 9 to change the magnetic force of the two magnetic force coils 9, so as to adjust the magnetic force on both sides of the magnetic ring 7 and keep the position of the impeller 4 stable. For example, when the impeller 4 moves downward, the displacement sensor 10 makes the lower magnetic force coil 9 generate a greater repulsive force to make the impeller 4 move upward and reset.

[0022] A pressure relief part, which includes a plurality of pressure relief holes 13 opened near the outlet end of the body 3. A moving cavity 14 communicating with the plurality of pressure relief holes 13 is formed in the body 3. A counterpoint ring 15 is slidably installed in the moving cavity 14. Counterpoint holes 16 matching with the plurality of pressure relief holes 13 are formed on the counterpoint ring 15. When the body 3 operates normally, the counterpoint holes 16 and the pressure relief holes 13 are in a staggered state, and at this time, the gas is discharged from the bottom of the body 3. When the air pressure in the body 3 is unstable and the impeller 4 moves downward by a certain distance, the counterpoint holes 16 and the pressure relief holes 13 are in corresponding positions, and at this time, part of the gas can be discharged outward through the pressure relief holes 13, effectively realizing the pressure relief process and improving the stability of the impeller 4.

[0023] A trigger assembly that mates with the alignment ring 15 is installed between the annular cavity 5 and the moving cavity 14. The trigger assembly consists of a moving ring 12 and a plurality of connecting rods 18. The moving ring 12 is slidably installed on one side of the annular cavity 5 near the outlet end of the machine body 3. A plurality of connecting rods 18 are fixedly installed between the moving ring 12 and the alignment ring 15. A through groove corresponding to the position of the displacement sensor 10 is formed in the moving ring 12. A plurality of springs 17 are installed between the alignment ring 15 and the moving cavity 14. When the impeller 4 moves downward in the annular cavity 5 and the displacement sensor 10 cannot control the magnetic coil 9 to keep the position of the impeller 4 stable, when the impeller 4 moves and causes the moving ring 12 to move accordingly, the alignment ring 15 can be driven to move downward simultaneously through the connecting rods 18. At this time, the relative positions of the alignment holes 16 and the pressure relief holes 13 change, and then the opening of the pressure relief hole 13 can be automatically controlled, realizing automatic control of the pressure relief process by using the position change of the impeller 4. The purpose of the pressure relief process is to keep the position of the impeller 4 stable. Therefore, the movement of the impeller 4 itself under the change of air pressure can be used as the driving force to keep the impeller 4 stable.

[0024] The flow guiding part, the flow guiding part includes a gas guiding ring 19 fixedly installed on the machine body 3, and the gas guiding ring 19 communicates with a plurality of pressure relief holes 13. A plurality of exhaust pipes 20 are connected between the gas guiding ring 19 and the outlet end of the machine body 3. The cooperation between the gas guiding ring 19 and the plurality of exhaust pipes 20 is used to guide and convey the gas discharged from the pressure relief holes 13, so that it is also discharged from the bottom of the machine body 3, avoiding the influence of the change of gas flow direction on the operation effect of the machine body 3.

[0025] An annular groove is formed on the inner wall of the machine body 3 away from the outlet end, and a rotating ring 21 is sealingly and rotatably installed in the annular groove. A scraping ring 22 that fits the inner wall of the machine body 3 is fixedly installed on the inner wall of the rotating ring 21. When the rotating ring 21 rotates, the inner wall of the machine body 3 can be scraped and cleaned by the scraping ring 22, improving the cleanliness inside the machine body 3. The scraped dust will be discharged under the action of the air flow when the impeller 4 is working.

[0026] A fixed gear ring 23 is fixedly installed on the side wall of the rotating ring 21. A driving assembly matched with the fixed gear ring 23 is installed on the air guiding ring 19. The driving assembly is composed of a fixed gear 24, a rotating rod 26, a connecting gear 27, a driving gear 28, a driving fan blade 29 and a driving gear ring 30. The fixed gear 24 is rotatably installed on the side wall of the machine body 3 through a rotating shaft, and the fixed gear 24 meshes with the fixed gear ring 23. The rotating rod 26 is rotatably installed on the side wall of the machine body 3. The connecting gear 27 is fixedly installed on the rotating rod 26, and the connecting gear 27 meshes with the fixed gear 24. The driving fan blade 29 is rotatably installed in the air guiding ring 19 in a sealed manner. The driving gear ring 30 is fixedly installed on the side wall of the driving fan blade 29. The driving gear 28 is fixedly installed at the other end of the rotating rod 26, and the driving gear 28 meshes with the driving gear ring 30. When the pressure relief hole 13 is opened, the gas entering the air guiding ring 19 can push the driving fan blade 29 to rotate. At this time, under the meshing effect of the driving gear ring 30 and the driving gear 28, the rotating rod 26 rotates simultaneously, and then the connecting gear 27 drives the fixed gear 24 to rotate. By using the meshing effect of the fixed gear 24 and the fixed gear ring 23, the rotating ring 21 drives the scraping ring 22 to rotate, automatically realizing the cleaning process inside the machine body 3.

[0027] A support block 25 is fixedly installed on the side wall of the machine body 3, and the support block 25 is rotatably connected to the rotating rod 26. A fixed block is also fixedly installed on the side wall of the machine body 3, and the fixed block is rotatably connected to the rotating shaft. The rotating shaft is fixedly connected to the fixed gear 24. The driving fan blade 29 is composed of an inner ring, an outer ring and a plurality of fan blades. The inner ring and the outer ring are both rotatably installed in the air guiding ring 19 at one end far from the exhaust pipe 20 in a sealed manner, and the inner ring and the outer ring are staggered with the positions of the plurality of pressure relief holes 13. The plurality of fan blades are all fixedly installed between the inner ring and the outer ring, and the fan blades correspond to the positions of the pressure relief holes 13. The driving gear ring 30 is fixedly installed on the side wall of the outer ring, and the driving gear ring 30 is rotatably connected to the air guiding ring 19 in a sealed manner.

[0028] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants, comprising a cold air island (1), the bottom of the cold air island (1) is fixedly installed with a machine body (3) through a bracket (2), and is characterized in that, Further comprising: An impeller (4) rotatably installed in the body (3). A magnetic ring (7) is fixedly installed on the side wall of the impeller (4) through a sealing ring (6). An annular cavity (5) matching the magnetic ring (7) is formed on the side wall of the body (3). Permanent magnets (8) matching the magnetic ring (7) are fixedly installed on the upper and lower side walls of the annular cavity (5). A magnetic force adjusting assembly matching the magnetic ring (7) is also installed in the annular cavity (5). The magnetic force adjusting assembly is used to adjust the magnitudes of the magnetic forces received on both sides of the magnetic ring (7), and further adjust the position of the impeller (4) in the body (3); A pressure relief part, which includes a plurality of pressure relief holes (13) formed near the outlet end of the body (3). A moving cavity (14) communicating with the plurality of pressure relief holes (13) is formed in the body (3). A counterposition ring (15) is slidably installed in the moving cavity (14). Counterposition holes (16) matching the plurality of pressure relief holes (13) are formed on the counterposition ring (15). A triggering assembly matching the counterposition ring (15) is installed between the annular cavity (5) and the moving cavity (14); A flow guiding part, which includes a gas guiding ring (19) fixedly installed on the body (3). The gas guiding ring (19) communicates with the plurality of pressure relief holes (13). A plurality of exhaust pipes (20) are connected between the gas guiding ring (19) and the air outlet end of the body (3).

2. The permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants according to claim 1, wherein A fixing ring (11) is fixedly installed on the side wall of the magnetic ring (7). The height of the annular cavity (5) is less than the height of the sealing ring (6), and the thickness of the fixing ring (11) is less than the thickness of the magnetic ring (7).

3. The permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants according to claim 2, characterized in that, The magnetic force adjusting assembly is composed of a displacement sensor (10) and two magnetic force coils (9). The displacement sensor (10) is fixedly installed in the annular cavity (5) and corresponds to the position of the fixing ring (11). The two magnetic force coils (9) are respectively fixedly installed at both ends of the annular cavity (5) and correspond to both ends of the magnetic ring (7) respectively. The displacement sensor (10) is signal-connected to the two magnetic force coils (9).

4. The permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants according to claim 3, wherein, The triggering assembly is composed of a moving ring (12) and a plurality of connecting rods (18). The moving ring (12) is slidably installed on one side of the annular cavity (5) near the outlet end of the body (3). The plurality of connecting rods (18) are fixedly installed between the moving ring (12) and the counterposition ring (15). A through groove corresponding to the position of the displacement sensor (10) is formed on the moving ring (12). A plurality of springs (17) are installed between the counterposition ring (15) and the moving cavity (14).

5. The permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants according to claim 1, wherein An annular groove is formed on the inner wall of the body (3) away from the outlet end. A rotating ring (21) is hermetically rotatably installed in the annular groove. A scraping ring (22) fitting the inner wall of the body (3) is fixedly installed on the inner wall of the rotating ring (21). A fixed gear ring (23) is fixedly installed on the side wall of the rotating ring (21). A driving assembly matching the fixed gear ring (23) is installed on the gas guiding ring (19).

6. The permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants according to claim 5, wherein The driving component consists of a fixed gear (24), a rotating rod (26), a connecting gear (27), a driving gear (28), a driving fan blade (29) and a driving gear ring (30). The fixed gear (24) is rotatably mounted on the side wall of the machine body (3) through a rotating shaft, and the fixed gear (24) meshes with the fixed gear ring (23). The rotating rod (26) is rotatably mounted on the side wall of the machine body (3). The connecting gear (27) is fixedly mounted on the rotating rod (26), and the connecting gear (27) meshes with the fixed gear (24). The driving fan blade (29) is rotatably mounted in the air guide ring (19) in a sealed manner. The driving gear ring (30) is fixedly mounted on the side wall of the driving fan blade (29). The driving gear (28) is fixedly mounted at the other end of the rotating rod (26), and the driving gear (28) meshes with the driving gear ring (30).

7. The permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants according to claim 6, wherein A support block (25) is fixedly mounted on the side wall of the machine body (3), and the support block (25) is rotatably connected to the rotating rod (26). A fixed block is also fixedly mounted on the side wall of the machine body (3), and the fixed block is rotatably connected to the rotating shaft. The rotating shaft is fixedly connected to the fixed gear (24).

8. The permanent magnet magnetic levitation shaftless low-noise and high-efficiency axial flow fan for thermal power plants according to claim 6, wherein, The driving fan blade (29) consists of an inner ring, an outer ring and a plurality of fan blades. The inner ring and the outer ring are both rotatably mounted in the air guide ring (19) at one end far from the exhaust pipe (20) in a sealed manner, and the inner ring and the outer ring are staggered with the positions of a plurality of pressure relief holes (13). A plurality of the fan blades are fixedly mounted between the inner ring and the outer ring, and the fan blades correspond to the positions of the pressure relief holes (13). The driving gear ring (30) is fixedly mounted on the side wall of the outer ring, and the driving gear ring (30) is rotatably connected to the air guide ring (19) in a sealed manner.

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