A method for improving the cooling effect of magnetic pole winding based on mixed flow fan

Abstract

The invention discloses a method for improving the cooling effect of a magnetic pole winding based on a mixed flow fan, and belongs to the technical field of cooling the high-speed, large-capacity hydro-turbine generator and pumped-storage power generation motor; by arranging mixed flow fans at both ends of a magnetic yoke, the cooling wind is divided into radial cooling wind for cooling the magnetic pole end coils and axial cooling wind entering the outer surface between the poles; a ventilation and cooling space for the outer surface between the poles is formed between two adjacent magnetic pole windings, and an axially arranged inter-pole ventilation partition plate is arranged in the ventilation and cooling space for the outer surface between the poles, so that the inter-pole ventilation partition plate and the outer surface of the magnetic pole winding form a separated axial ventilation duct; thereby, the cooling of the rotor magnetic pole winding of a high-speed, large-capacity hydro-turbine generator and a pumped-storage power generation motor, which cannot adopt radial ventilation cooling in the inter-pole region of the magnetic pole winding, is ensured, and the problem of large difference in cooling effect between the windward side and the leeward side of the traditional structure is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of cooling high-speed, large-capacity hydro-generators and pumped-storage power generation motors, and in particular relates to a method for improving the cooling effect of a magnetic pole winding based on a mixed flow fan. Background Art

[0002] When the rotors of hydro-turbine generators and pumped-storage power generation motors rotate in a certain direction, the cooling of the windward side of the outer side of the pole winding is better than that of the leeward side of the pole. The temperature rise of the leeward side is often higher than that of the windward side, resulting in a large temperature difference between the two sides of the pole winding. At the same time, for high-speed hydro-turbine generators using axial ventilation cooling, due to insufficient axial air inlet pressure head between the poles and air leakage between the poles, the cooling air often enters the axial air duct between the poles from the axial end, and it is difficult to reach the middle area of ​​the pole. It enters the stator-rotor air gap at a short position in the end area, resulting in the middle area of ​​the pole winding not being effectively cooled, resulting in uneven temperature rise of the pole winding, which is easy to cause the problem of uncoordinated thermal deformation of the pole winding.

[0003] In the prior art, in order to improve the cooling effect of the pole winding, a Chinese invention patent with publication number CN108258824A and publication date July 6, 2018 discloses a combined internal and external cooling method for the rotor pole winding, in which part of the cooling gas enters the longitudinal flow channel of the current-carrying bar along the axial coil edge of the pole coil (or pole winding) to cool the inner surface of the pole coil, and the remaining cooling gas enters the channel between the two pole coils to form an external cooling ventilation path to cool the outer surface of the pole coil. The internal cooling ventilation path and the external cooling ventilation path in the invention are both axial ventilation paths.

[0004] The internal cooling ventilation duct and the external cooling ventilation duct of this patent are both axial ventilation ducts, which are easy to implement and have lower costs, and have a wide range of applications. In addition, since there is no obstruction from the ventilation partition device, the flow rate and flow velocity of the cooling gas will not be affected, which greatly improves the cooling effect of the pole coil, and thus improves the cooling effect of the entire rotor pole winding. However, this patent does not involve the implementation method of the end axial wind guide structure, which may not produce a sufficiently large axial pressure head, and the depth of the cooling gas flowing from the pole end to the middle may be limited, resulting in insufficient cooling effect in the middle of the pole; there is no separation device between the poles, which cannot eliminate the cooling interference of the windward and leeward sides of the pole winding; the cooling of the outer surfaces of the upper and lower ends of the pole winding is not considered, and the rotor cooling air volume is not distributed and controlled, resulting in insufficient overall uniformity of the pole winding cooling.

[0005] In addition, some high-speed, large-capacity hydroelectric generators and pumped-storage power generation motors have high speeds and small diameters, which means that the rotor yoke and shaft can only be designed in an integrated manner. It is impossible to set radial ventilation ducts on the yoke, and thus it is impossible to use radial ventilation to cool the pole windings. The cooling of the pole windings almost entirely relies on axial ventilation cooling. In this way, improving the effect of axial ventilation cooling becomes very critical and has a significant impact. How to solve the cooling problem of the pole windings of such units has become a common problem in the industry. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned existing problems and propose a method for improving the cooling effect of the pole winding based on a mixed flow fan, so as to solve the problems of unstable cooling efficiency, excessive dissipation and loss of cooling air in the prior art.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A method for improving the cooling effect of a magnetic pole winding based on a mixed flow fan is as follows:

[0009] s1: An inter-pole outer surface ventilation and cooling space is formed between two adjacent pole windings, an inter-pole ventilation partition plate is arranged axially along the inter-pole outer surface ventilation and cooling space, mixed flow fans are arranged at both ends of the yoke, and stationary end wind shield plates are arranged at both ends of the pole winding, which are fixed to the frame and in contact with the stationary stator core outside the rotor;

[0010] s2: The axial cooling route of the axial outer surface of the pole winding is as follows: the inter-pole ventilation partition plate and the axial outer surface of the pole winding form an axial ventilation duct, and the radial cooling air at both ends of the yoke is changed into axial cooling air through the mixed flow fans at both ends of the yoke, and enters the axial ventilation duct to reach the middle of the pole winding, thereby realizing axial cooling of the axial outer surface of the pole winding;

[0011] s3: The radial cooling route of the outer surface of the pole winding end is: the outer surface of the pole winding end and the end wind shield form a radial ventilation duct, and the radial cooling air at both ends of the yoke enters the radial ventilation duct formed by the end wind shield and the pole winding end through the mixed flow fan and then flows axially into the stator and rotor air gap to achieve radial cooling of the outer surface of the pole winding end.

[0012] The axial ventilation ducts are two axial gaps respectively formed by the inter-pole ventilation partition plate and the axial outer surfaces of two adjacent magnetic pole windings.

[0013] The radial ventilation ducts are two radial gaps formed by the end wind shields at both ends and the outer surfaces of the ends of the magnetic pole windings at both ends.

[0014] An insulating plate is arranged outside the magnetic pole winding, the magnetic pole winding is in contact with the insulating plate, and the insulating plate is in contact with a supporting plane on the magnetic pole core.

[0015] The inter-pole ventilation partition plate includes an outer structure, a windshield wing plate and a T-tail structure; the outer structure is arranged between adjacent pole windings, and both side edges of the outer structure are parallel to the axial outer surfaces of the adjacent pole windings; the T-tail structure is a fixed structure; the T-tail structure is connected and fixed to the T-tail slot of the yoke; circumferential windshield wing plates are arranged on both sides of the outer diameter side of the outer structure; the outer structure, the windshield wing plate and the T-tail structure are connected as a whole.

[0016] The T-tail structure is in contact with and connected to the T-tail slot of the yoke through a gasket or a wedge key.

[0017] The wind shielding wing plate is provided with straight sections of equal width and equal axial length at both ends.

[0018] The axial length H of the straight section of equal width is at least 100 mm.

[0019] The circumferential gap between the outer circumferential windshield plate of the equal-width straight section and the outer insulating plate of the magnetic pole winding is 1 mm.

[0020] The circumferential width of the windshield wing plate decreases axially from the end of the straight section of equal width to the middle.

[0021] The equal-width straight section can be further lengthened for a magnetic pole with a longer axial length, but the total length of both ends thereof is no more than 1 / 5 of the total length of the magnetic pole winding.

[0022] The mixed flow fan adopts fan blades arranged in a circumferential periodic manner, with the fan-shaped space corresponding to a magnetic pole body and an adjacent magnetic pole as one period. The fan blades are evenly arranged in the circumference, and each period contains two fan blades. The two fan blades are respectively located on both sides of the magnetic pole space, and their axial projection positions are close to the edge positions of the adjacent magnetic pole bodies.

[0023] The outer diameter side of the fan part of the mixed flow fan corresponding to the inter-pole area of ​​the magnetic poles extends to the outside of the magnetic pole winding, and the tail part is smoothly inclined toward the axial direction of the magnetic pole winding. The terminal end face of the fan part of the mixed flow fan corresponding to the inter-pole area of ​​the magnetic poles is close to the end face of the inter-pole ventilation partition plate.

[0024] The outer diameter side of the fan portion of the mixed flow fan corresponding to the pole body area does not exceed the inner surface of the pole core.

[0025] The axial height of the fan portion of the mixed flow fan corresponding to the inter-pole region of the magnetic poles is greater than the axial height of the fan portion corresponding to the pole body region of the magnetic poles.

[0026] The air volume of the axial ventilation duct is greater than the air volume of the radial ventilation ducts at both ends of the pole winding.

[0027] The ratio of the air volume of the axial ventilation duct to the air volume of the radial ventilation duct is 8:2.

[0028] The stationary end wind shield is arranged in a full circle, and the inner diameter radius of the end wind shield is smaller than the outer diameter radius of the fan part of the mixed flow fan corresponding to the pole body area, and is concentric; the outer diameter side of the end wind shield extends axially toward the middle of the pole and contacts the end of the stator core.

[0029] The end wind shield plate is axially higher than the outer diameter side portion of the mixed flow fan, and the spacing is 10-15 mm.

[0030] The thickness of the inter-pole copper bars of the pole winding is K=6~8mm, and the thickness of all copper bars is consistent; the pole winding adopts a heat dissipation turn structure, that is, the first inner turn of the copper bar uses a copper bar with a width of A, the second turn uses a copper bar with a width of A+L, the third and fourth turns use a copper bar with a width of A, and the fifth turn uses a copper bar with a width of A+L. In this way, a copper bar with a width of A+L is used every two copper bars with a width of A, and the ratio of L to K is 1.5~3.

[0031] The advantages of adopting the present invention are:

[0032] 1. The cooling air is introduced into the surface of the inter-pole winding through the inter-pole mixed flow fan and the ventilation partition plate, the radial cooling air at the end is converted into the axial cooling air between the poles, and the cooling ventilation ducts on the windward and leeward sides of the pole winding are separated to prevent flow and cooling interference.

[0033] 2. The tail of the outer diameter side of the mixed flow fan at both ends of the yoke is close to the end of the inter-pole ventilation partition plate, which can avoid the escape and loss of the inter-pole cooling air volume at the end, effectively enhance the inter-pole wind guiding effect, and improve the cooling effect of the inter-pole axial outer surface.

[0034] 3. By adjusting the height difference between the pole body area and the inter-pole area of ​​the mixed flow fan, the air volume distribution of the inter-pole axial ventilation cooling and the end radial ventilation cooling can be regulated, so that the end of the pole winding and the outer surface of the inter-pole can obtain sufficient air volume, thereby achieving the purpose of improving cooling uniformity.

[0035] Fourth, by setting the wind shield wing plates on both sides of the inter-pole ventilation partition plate and changing the circumferential width of the wind shield wing plates in the axial direction, the cooling air can flow along the outer surface of the axial pole winding as much as possible, avoiding the inter-pole cooling air from diffusing radially too quickly and affecting the cooling of the pole winding. In addition, the axial air volume distribution of the inter-pole cooling air that finally enters the stator and rotor air gap can be controlled, and combined with the cooling air that enters the stator and rotor air gap at the end, the overall cooling air can be evenly distributed in the stator and rotor air gap along the axial direction.

[0036] 5. Through partitioning, the cooling effect of the windward and leeward sides, middle and ends of the pole winding can be improved, the temperature difference can be reduced, the thermal deformation difference can be reduced, and the structural safety can be improved.

[0037] Sixth, the inter-pole copper bars of the magnetic pole winding adopt a heat dissipation turn structure, and a wider copper bar is used every two copper bars with smaller widths, and the ratio of the size of the extended part of the wide copper bar to the thickness of the two copper bars is 1.5~3. This can greatly increase the heat dissipation area of ​​the outer surface between the poles of the magnetic pole winding. Typically, for a magnetic pole winding with 40 turns of copper bars, if the copper bar thickness is 6mm and the size of the extended part is set to 24mm, the heat dissipation area of ​​the outer surface between the poles can be increased by 2.6 times, thereby greatly improving the cooling effect.

[0038] 7. The ventilation partition plate is fixed by ventilation wedge keys or the like. When it is necessary to dismantle and repair the rotor poles on site in the pit of the power station, the wedge keys can be removed first, and then the ventilation partition plate can be taken out, so that a single pole can be easily dismantled on site.

[0039] 8. The outer diameter of the fan part of the mixed flow fan corresponding to the pole body area is smaller than the inner side of the pole, which makes it possible to dismantle and repair the rotor poles in situ on site in the power station pit without dismantling the mixed flow fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the rotor of the hydro-generator of the present invention;

[0041] Figure 2 for Figure 1 AA cross-sectional view of the turbine generator rotor;

[0042] Figure 3 for Figure 1 BB cross-sectional view of the turbine generator rotor;

[0043] Figure 4 for Figure 2 CC section view;

[0044] Figure 5 for Figure 4 K-direction expansion diagram;

[0045] Figure 6 It is a schematic diagram of a mixed flow fan;

[0046] Figure 7 for Figure 6 Schematic diagram of N-way expansion.

[0047] Markings in the figure are: 1. pole winding, 2. pole core, 3. inter-pole ventilation partition plate, 4. mixed flow fan, 5. end wind shield, 6. stator core, 7. stator-rotor air gap, 8. yoke, 9. radial ventilation duct, 10. axial ventilation duct, 11. wind shield wing plate, 12. insulation plate, 13. outer surface of pole winding end, 14. T-tail structure, 15. fan part corresponding to the inter-pole area of ​​the pole, 16. fan part corresponding to the pole body area, 17. fan guide blade, 18. ventilation and cooling space on the outer surface of the pole, 19. outer structure, 20. axial outer surface of the pole winding, 21. straight section of equal width. DETAILED DESCRIPTION

[0048] Example 1

[0049] This embodiment further illustrates the structure and principle of the present invention in conjunction with the accompanying drawings:

[0050] A method for improving the cooling effect of a magnetic pole winding based on a mixed flow fan is as follows:

[0051] s1: An inter-pole outer surface ventilation and cooling space 18 is formed between two adjacent pole windings 1, an inter-pole ventilation partition plate 3 is arranged axially along the inter-pole outer surface ventilation and cooling space 18, mixed flow fans 4 are arranged at both ends of the yoke 8, and stationary end wind shield plates 5 fixed to the frame and in contact with the stationary stator core 6 outside the rotor are arranged at both ends of the pole winding 1;

[0052] s2: The axial cooling route of the axial outer surface of the pole winding is as follows: the inter-pole ventilation partition plate 3 and the axial outer surface 20 of the pole winding form an axial ventilation duct 10, and the radial cooling wind at both ends of the yoke 8 is changed into axial cooling wind through the mixed flow fans 4 at both ends of the yoke 8, and enters the axial ventilation duct 10 to reach the middle of the pole winding 1, thereby realizing axial cooling of the axial outer surface 20 of the pole winding;

[0053] s3: The radial cooling route of the outer surface of the pole winding end is: the outer surface 13 of the pole winding end and the end wind shield 5 form a radial ventilation duct 9, and the radial cooling air at both ends of the yoke 8 enters the radial ventilation duct 9 formed by the end wind shield 5 and the end of the pole winding 1 through the mixed flow fan 4, and then flows axially into the stator-rotor air gap 7, thereby realizing radial cooling of the outer surface 13 of the pole winding end.

[0054] The axial ventilation ducts 10 are two axial gaps formed by the inter-pole ventilation partition plate 3 and the axial outer surfaces 20 of two adjacent magnetic pole windings.

[0055] The radial ventilation duct 9 is two radial gaps formed by the end wind shield plates 5 at both ends and the outer surfaces 13 of the pole winding ends at both ends.

[0056] An insulating plate 12 is disposed outside the magnetic pole winding 1 , the magnetic pole winding 1 is in contact with the insulating plate 12 , and the insulating plate 12 is in contact with a supporting plane on the magnetic pole core 2 .

[0057] The inter-pole ventilation partition plate 3 includes an outer structure 19, a wind shield wing plate 11 and a T-tail structure 14; the outer structure 19 is arranged between adjacent pole windings 1, and the two side edges of the outer structure 19 are parallel to the axial outer surfaces 20 of the adjacent pole windings; the T-tail structure 14 is a fixed structure; the T-tail structure 14 is connected and fixed to the T-tail groove of the yoke 8; circumferential wind shield wing plates 11 are arranged on both sides of the outer diameter side of the outer structure 19; the outer structure 19, the wind shield wing plate 11 and the T-tail structure 14 are connected as a whole.

[0058] The T-tail structure 14 is in contact with and connected to the T-tail groove of the yoke 8 through a gasket or a wedge-shaped key.

[0059] The wind shielding wing plate 11 is provided with equal width straight sections 21 of the same axial length at both ends.

[0060] The axial length H of the equal-width straight section 21 is at least 100 mm.

[0061] The circumferential gap between the circumferential windshield wing plate 11 outside the equal-width straight section 21 and the insulating plate 12 outside the magnetic pole winding is 1 mm.

[0062] The circumferential width of the windshield wing plate 11 gradually decreases from the end of the equal-width straight section 21 to the middle along the axial direction.

[0063] The equal-width straight section 21 can be further lengthened for a magnetic pole with a longer axial length, but the total length at both ends thereof is no more than 1 / 5 of the total length of the magnetic pole winding 1 .

[0064] The mixed flow fan 4 adopts fan blades 17 that are arranged in a circumferential periodic manner, with the fan-shaped space corresponding to a magnetic pole body and an adjacent magnetic pole as one period. The fan blades 17 are evenly arranged in the circumference, and each period contains two fan blades 17. The two fan blades 17 are respectively located on both sides of the magnetic pole space, and their axial projection positions are close to the edge positions of the adjacent magnetic pole bodies.

[0065] The outer diameter side of the fan part 15 of the mixed flow fan 4 corresponding to the inter-pole area of ​​the magnetic poles extends to the outside of the magnetic pole winding 1, and the tail part is in a shape that is smoothly inclined axially toward the magnetic pole winding 1. The end face of the fan part 15 of the mixed flow fan 4 corresponding to the inter-pole area of ​​the magnetic poles is close to the end face of the inter-pole ventilation partition plate 3.

[0066] The outer diameter side of the fan portion 16 of the mixed flow fan 4 corresponding to the pole body area does not exceed the inner side surface of the pole core 2.

[0067] The axial height of the fan portion 15 of the mixed flow fan 4 corresponding to the inter-pole region of the magnetic poles is greater than the axial height of the fan portion 16 corresponding to the pole body region of the magnetic poles.

[0068] The air volume of the axial ventilation duct 10 is greater than the air volume of the radial ventilation ducts 9 at both ends of the pole winding.

[0069] The ratio of the air volume of the axial ventilation duct 10 to the air volume of the radial ventilation duct 9 is 8:2.

[0070] The stationary end wind shield plate 5 is arranged in a full circle, and the inner diameter radius of the end wind shield plate 5 is smaller than the outer diameter radius of the fan part 16 of the corresponding magnetic pole body area of ​​the mixed flow fan 4, and is concentric; the outer diameter side of the end wind shield plate 5 extends axially toward the middle of the magnetic pole and contacts the end of the stator core 6.

[0071] The end wind shield plate 5 is axially higher than the outer diameter side portion of the mixed flow fan 4, and the spacing is 10-15 mm.

[0072] The thickness K of the inter-pole copper bar of the pole winding 1 is 6-8 mm, and the thickness of all copper bars is the same; the pole winding 1 adopts a heat dissipation turn structure, that is, the first inner turn of the copper bar uses a copper bar with a width of A, the second turn uses a copper bar with a width of A+L, the third and fourth turns use a copper bar with a width of A, and the fifth turn uses a copper bar with a width of A+L. In this way, a copper bar with a width of A+L is used every two copper bars with a width of A, and the ratio of L to K is 1.5-3.

[0073] Example 2

[0074] like Figure 1-5 As shown, mixed flow fans 4 are arranged at both ends of the yoke 8 to convert the radial cooling wind at the end into axial cooling wind between the poles; in the ventilation and cooling space 18 of the outer surface between the poles of the pole winding formed by adjacent poles, an axially arranged inter-pole ventilation partition plate 3 is arranged to form two axial ventilation ducts 10 with the axial outer surface 20 of the pole winding; stationary end wind shield plates 5 fixed to the frame and in contact with the stationary stator core 6 outside the rotor are arranged at both ends of the pole winding 1 to form radial ventilation ducts 9 with the outer surface 13 of the end of the pole winding; the mixed flow fan 4, the inter-pole ventilation partition plate 3, and the axial outer surface 20 of the pole winding are combined to form an axial ventilation cooling channel; the mixed flow fan 4, the end wind shield plate 5, and the outer surface 13 of the end of the pole winding constitute a radial ventilation cooling channel.

[0075] The axial cooling route of the axial outer surface of the pole winding is as follows: the radial cooling wind at the end changes direction through the mixed flow fans 4 at both ends of the yoke 8, enters the axial ventilation duct 10 formed between the inter-pole ventilation partition plate 3 and the axial outer surface 20 of the pole winding, and reaches the middle of the winding, thereby cooling the axial outer surface 20 of the pole winding. During the axial ventilation process, the cooling wind gradually flows out radially and enters the stator-rotor air gap 7, and the radial outflow air volume gradually increases from the end to the middle.

[0076] The radial cooling route of the outer surface of the pole winding end is as follows: the end radial cooling wind passes through the mixed flow fans 4 at both ends of the yoke 8, enters the radial ventilation duct 9 formed by the end wind shield 5 and the outer surface 13 of the pole winding end, and finally flows axially into the stator-rotor air gap 7 to achieve cooling of the outer surface 13 of the pole winding end.

[0077] The two parts of cooling air for axial outer surface cooling and end outer surface cooling finally enter the stator-rotor air gap 7. Through the cooperation of the two parts of the ventilation structure, the cooling air entering the stator-rotor air gap 7 is basically evenly distributed along the axial direction.

[0078] like Figure 4-5 As shown, the inter-pole ventilation partition plate 3 includes an outer structure 19, a wind shield wing plate 11 and a T-tail structure 14; the outer structure 19 is arranged between adjacent pole windings 1, and the two side edges of the outer structure 19 are parallel to the axial outer surfaces 20 of the adjacent pole windings; the T-tail structure 14 is a fixed structure; the T-tail structure 14 is connected and fixed to the T-tail groove of the yoke 8; circumferential wind shield wing plates 11 are arranged on both sides of the outer diameter side of the outer structure 19; the outer structure 19 is located on the outer diameter side of the T-tail structure 14; the outer structure 19, the wind shield wing plate 11 and the T-tail structure 14 are connected as a whole.

[0079] Circumferential windshield wing plates 11 are arranged on both sides of the outer diameter side of the inter-pole ventilation partition plate 3. The windshield wing plates 11 are provided with a straight section 21 of equal width at both ends. The circumferential width of the windshield wing plates 11 gradually decreases from the end of the straight section 21 to the middle along the axial direction, that is, the circumferential gap between the windshield wing plates 11 and the outer surface of the pole winding 1 gradually increases, so that the axial cooling wind can flow axially toward the middle of the pole winding 1 while gradually flowing out radially, and the radial outflowing wind volume gradually increases from the end to the middle. This part of the cooling wind cooperates with the radial cooling wind at the end, so that the radial wind volume that finally enters the stator-rotor air gap 7 is basically uniform along the axial direction.

[0080] The wind shielding wing 11 of the inter-pole ventilation partition plate 3 is provided with a straight section 21 of equal width with an axial length of H=100mm at both ends. The circumferential gap between the edge of the straight section 21 and the insulating plate 12 outside the pole winding 1 is about 1mm. This circumferential gap is the installation gap and the gap to adapt to the thermal deformation and mechanical deformation during operation. In the straight section 21 of equal width, the inter-pole ventilation partition plate 3 and the yoke 8, the outer surface of the inner diameter side of the pole winding 1 and the outer surface between the poles together constitute a space that only allows the cooling air to pass axially. The setting of the straight section 21 of equal width has two functions: on the one hand, it forms an almost closed space with the outer surface of the pole winding 1 in the end area, does not produce excessive end leakage, and strengthens the axial cooling effect; on the other hand, during the rotation of the rotor, the straight section 21 of equal width can be close to the insulating plate 12 outside the pole winding when the pole winding 1 is deformed outward, providing circumferential support for the inter-pole ventilation partition plate 3 itself. Furthermore, for the axially longer magnetic pole winding 1, a straight section 21 of equal width can also be set in the middle area of ​​the inter-pole ventilation partition plate 3, and the axial length is controlled within 50 mm, so as to strengthen the circumferential fixation of the inter-pole ventilation partition plate 3 without affecting the cooling and ventilation in the middle.

[0081] The wind shielding wing plate 11 of the inter-pole ventilation partition plate 3 has an equal width straight section 21 at the end, and its axial length H can be flexibly set according to the axial length of the pole winding, and its maximum total length at both ends does not exceed 1 / 5 of the total length of the pole winding.

[0082] The inter-pole ventilation partition plate 3 is connected to the T-tail groove of the yoke 8 through the T-tail structure 14, and its inner diameter side plane is in reliable contact with the yoke 8 through a gasket or a wedge key to ensure that the partition device is firmly fixed.

[0083] like Figure 6-7 As shown, the mixed flow fan 4 adopts fan blades 17 arranged in a circumferential periodic manner, that is, the fan blades 17 are evenly arranged in a circle with the fan-shaped space corresponding to a pole body and an adjacent pole body as a period, and each period contains two fan blades 17, which are respectively located between the poles and close to the edge of the adjacent pole body; the outer diameter side tail of the mixed flow fan 4 is in a shape that is smoothly inclined toward the axial direction of the pole, and the terminal end face of the fan part 15 corresponding to the inter-pole area of ​​the pole is close to the end face of the inter-pole ventilation partition plate 3, so as to guide all the inter-pole cooling air into the inter-pole axial ventilation duct 10 as much as possible, thereby reducing the escape of cooling air in the stator and rotor air gap 7.

[0084] The mixed flow fan 4 converts the radial cooling air in the end area into axial cooling air between the poles, and uses the inter-pole ventilation partition plate 3 and the magnetic yoke 8, the outer surface of the inner diameter side of the pole winding 1 and the outer surface between the poles to form a space that only allows the cooling air to pass axially. Compared with the existing technology, it can effectively improve the inter-pole wind guiding effect, reduce the escape and loss of the inter-pole cooling air volume, and improve the cooling effect of the inter-pole outer surface.

[0085] The thickness of the inter-pole copper bar of the pole winding 1 is K=6~8mm, and the thickness of all copper bars is the same; the pole winding 1 adopts a heat dissipation turn structure, that is, the first inner turn of the copper bar uses a copper bar with a width of A, the second turn uses a copper bar with a width of A+L, the third and fourth turns use a copper bar with a width of A, and the fifth turn uses a copper bar with a width of A+L. In this way, a copper bar with a width of A+L is used every two copper bars with a width of A, and the ratio of L to K is 1.5~3, which greatly increases the heat dissipation area of ​​the outer surface between the poles of the pole winding 1 and greatly improves the cooling effect.

Claims

1. A method for improving the cooling effect of a magnetic pole winding based on a mixed flow fan, characterized in that: The details are as follows: s1: An inter-pole outer surface ventilation and cooling space (18) is formed between two adjacent magnetic pole windings (1), an inter-pole ventilation partition plate (3) is arranged axially along the inter-pole outer surface ventilation and cooling space (18), mixed flow fans (4) are arranged at both ends of the magnetic yoke (8), and stationary end wind shield plates (5) are arranged at both ends of the magnetic pole winding (1) and are fixed to the frame and in contact with the stationary stator core (6) outside the rotor; s2: The axial cooling route of the axial outer surface of the pole winding is as follows: the inter-pole ventilation partition plate (3) and the axial outer surface (20) of the pole winding form an axial ventilation duct (10), and the radial cooling air at both ends of the yoke (8) is changed into axial cooling air through the mixed flow fans (4) at both ends of the yoke, and enters the axial ventilation duct (10) to reach the middle of the pole winding (1), thereby realizing axial cooling of the axial outer surface (20) of the pole winding; the inter-pole ventilation partition plate (3) includes an outer structure (19), a wind shield wing The invention relates to a magnetic yoke (8) having a plurality of magnetic poles and a plurality of magnetic poles, wherein the plurality of magnetic poles are connected to each other and are provided with a plurality of circumferential windshield wing plates (11). The plurality of magnetic poles are connected to each other and are provided with a plurality of circumferential windshield wing plates (11). The plurality of magnetic poles are connected to each other and are provided with a plurality of circumferential windshield wing plates (11). The plurality of magnetic poles are connected to each other and are provided with a plurality of circumferential windshield wing plates (11). The plurality of magnetic poles are connected to each other and are provided with a plurality of circumferential windshield wing plates (11). s3: The radial cooling route of the outer surface of the pole winding end is as follows: the outer surface of the pole winding end (13) and the end wind shield (5) form a radial ventilation duct (9), and the radial cooling air at the two ends of the yoke (8) enters the radial ventilation duct (9) formed by the end wind shield (5) and the end of the pole winding (1) through the mixed flow fan (4), and then flows axially into the stator-rotor air gap (7), thereby achieving radial cooling of the outer surface (13) of the pole winding end.

2. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 1, characterized in that: The axial ventilation duct (10) is two axial gaps respectively formed by the inter-pole ventilation partition plate (3) and the axial outer surfaces (20) of two adjacent magnetic pole windings.

3. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 1, characterized in that: The radial ventilation duct (9) is two radial gaps formed by the end wind shields (5) at both ends and the outer surfaces (13) of the magnetic pole winding ends at both ends.

4. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 1, characterized in that: An insulating plate (12) is arranged outside the magnetic pole winding (1), the magnetic pole winding (1) is in contact with the insulating plate (12), and the insulating plate (12) is in contact with a supporting plane on the magnetic pole core (2).

5. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 4, characterized in that: The T-tail structure (14) contacts and is connected to the T-tail slot of the yoke via a gasket or a wedge-shaped key.

6. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 5, characterized in that: The wind shielding wing plate (11) is provided with straight sections (21) of equal width and equal axial length at both ends.

7. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 6, characterized in that: The axial length H of the equal-width straight section (21) is at least 100 mm.

8. A method for improving the cooling effect of a magnetic pole winding based on a mixed flow fan according to claim 6 or 7, characterized in that: The circumferential gap between the circumferential windshield wing plate (11) on the outer side of the equal-width straight section (21) and the insulating plate (12) on the outer side of the magnetic pole winding is 1 mm.

9. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 6, characterized in that: The circumferential width of the windshield wing plate (11) decreases axially from the end of the straight section (21) of equal width toward the middle.

10. A method for improving the cooling effect of a magnetic pole winding based on a mixed flow fan according to claim 6 or 7, characterized in that: The total length of the two axial ends of the equal-width straight section (21) is no greater than 1 / 5 of the total length of the magnetic pole winding (1).

11. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 1, characterized in that: The mixed flow fan (4) uses fan blades (17) that are arranged in a circumferential periodic manner, with a sector-shaped space corresponding to a magnetic pole body and an adjacent magnetic pole interpole as one period, and the fan blades (17) are evenly arranged in the circumference, and each period contains two fan blades (17), the two fan blades (17) are respectively located on both sides of the magnetic pole interpole, and their axial projection positions are close to the edge positions of the adjacent magnetic pole bodies.

12. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 11, characterized in that: The outer diameter side of the fan portion (15) of the mixed flow fan (4) corresponding to the inter-pole region of the magnetic poles extends to the outside of the magnetic pole winding (1), and the tail portion is inclined axially toward the magnetic pole winding (1), and the end end face of the fan portion (15) of the mixed flow fan (4) corresponding to the inter-pole region of the magnetic poles is close to the end face of the inter-pole ventilation partition plate (3).

13. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 11, characterized in that: The outer diameter side of the fan portion (16) of the mixed flow fan (4) corresponding to the magnetic pole body region does not extend beyond the inner side surface of the magnetic pole core (2).

14. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 11, characterized in that: The axial height of the fan portion (15) of the mixed flow fan (4) corresponding to the magnetic pole inter-pole region is greater than the axial height of the fan portion (16) corresponding to the magnetic pole body region.

15. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 1, characterized in that: The air volume of the axial ventilation duct (10) is greater than the air volume of the radial ventilation ducts (9) at both ends of the magnetic pole winding.

16. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 15, characterized in that: The ratio of the air volume of the axial ventilation duct (10) to the air volume of the radial ventilation duct (9) is 8:

2.

17. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 1, characterized in that: The end wind shield (5) is arranged in a full circle, the inner diameter side radius of the end wind shield (5) is smaller than the outer diameter side radius of the fan portion (16) of the mixed flow fan (4) corresponding to the magnetic pole body region, and is concentric; the outer diameter side of the end wind shield (5) extends obliquely along the axial direction toward the middle of the magnetic pole to the end of the stator core (6) and contacts it.

18. The method for improving the cooling effect of magnetic pole windings based on a mixed flow fan according to claim 17, characterized in that: The end wind shield plate (5) is axially higher than the outer diameter side portion of the mixed flow fan (4), and the spacing is 10-15 mm.

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