Hybrid ventilation cooling system of double-shaft excitation motor

Abstract

The invention provides a hybrid ventilation cooling system of a double-shaft excitation motor. The system comprises a stator iron core, a stator radial ventilation duct, a circular ring type circumferential air gap partition plate, a step section type auxiliary slot ventilation duct, a double-radial straight air duct, an alternating radial air duct and an air gap. A stator radial ventilation duct is formed between the two stator iron core lamination segments, and a circular ring type circumferential air gap partition plate is arranged in the radial ventilation duct in a stator winding high-temperature area. The rotor auxiliary slot corresponding to one side provided with the circumferential air gap partition plate is a stepped cross section type auxiliary slot ventilating duct, and the radial ventilating ducts are double radial straight air ducts and alternate radial air ducts. The circumferential air gap partition plate can enable hydrogen coming out of the double-radial-direction straight air channel to directly enter the stator radial-direction ventilation duct. The stepped section type auxiliary slot ventilating duct and the biradial straight air duct can increase the uniformity of air distribution, reduce the wind resistance and lower the temperature of the rotor; and the axial temperature distribution of the rotor is more uniform due to the rectangular section type auxiliary slot ventilating ducts and the alternate radial air ducts.

Description

Technical Field

[0001] The invention relates to the technical field of motor rotor cooling, and in particular to a hybrid ventilation cooling system for a dual-axis excitation motor. Background Art

[0002] As the installed capacity of large generators continues to increase, their electromagnetic load and thermal load are also increasing, and the temperature of the windings and cores is very high, which seriously affects the life and safety of the generator-phase condenser. Therefore, in order to reduce the temperature of the stator and rotor windings and cores, a corresponding cooling system for large generators is proposed, such as a water-hydrogen-hydrogen cooling system. The principle is that the strands in the stator winding are divided into solid strands and hollow strands, and water is passed through the hollow strands, while hydrogen is filled inside the generator-phase condenser. In order to further reduce the temperature of the rotor winding, auxiliary slots are opened in the rotor core, and radial ventilation grooves are opened inside the rotor winding to facilitate the passage of hydrogen to reduce the temperature of the rotor winding and reduce the risk of overheating of the rotor winding.

[0003] However, since hydrogen cools the rotor winding through the radial ventilation groove of the rotor, the fluidity of the hydrogen coming out is affected by rotation, centrifugal force and the turbulent state, and it does not enter the radial ventilation groove of the stator in a linear and regular manner. In addition, the water in the stator flows axially at the nose of the stator winding at one end, absorbs heat, and flows out from the nose of the stator winding at the other end. During the whole process, the water temperature continues to rise until it reaches the water outlet. Therefore, the temperature of the stator winding is highest near the water outlet of the stator winding, which causes the temperature of the stator winding to be unevenly distributed along the axial direction, which is easy to cause thermal stress, causing the hollow strands to bend, the insulation to age, and cause serious accidents. Summary of the invention

[0004] The embodiment of the present invention provides a dual-axis excitation motor hybrid ventilation cooling system to effectively reduce the stator and rotor temperatures of the generator and ensure safe and reliable operation of a large-capacity generator.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme.

[0006] A dual-axis excitation motor hybrid ventilation cooling system, comprising:

[0007] A stator core (1), a stator radial ventilation groove (2), a stepped cross-section auxiliary slot ventilation duct (3), a double radial straight air duct (4), a rectangular cross-section auxiliary slot ventilation duct (5), an alternating radial air duct (6), an air gap (7) and an annular circumferential air gap partition (8);

[0008] The annular circumferential air gap partition (8) is installed in the radial ventilation groove (2) of the stator, the thickness of the annular circumferential air gap partition (8) is 1 / 4 of the width of the ventilation groove, and the width is 1 / 2 of the air gap length; the annular circumferential air gap partition (8) is arranged in the radial ventilation groove of the stator high temperature zone, and the number of the annular circumferential air gap partitions (8) is 1 / 2 of the number of the radial ventilation grooves of the stator;

[0009] The stator radial ventilation groove (2) is located between two adjacent stator core (1) lamination segments, and the air gap (7) is located between the stator and the rotor;

[0010] The stepped cross-section auxiliary slot ventilation channel (3) is located at a position corresponding to the high temperature zone of the stator. The inlet of the stepped cross-section auxiliary slot ventilation channel (3) is in a stepped shape, that is, the area of ​​the position close to the shaft is small, and the area of ​​the position close to the slot bottom is large. From the end of the rotor to the center of the rotor, the stepped cross-section area remains unchanged.

[0011] The double radial straight air duct (4) is two ventilation ducts with long rectangular cross-sections inside the rotor winding, located at corresponding positions of the stator high temperature zone, the bottom of the double radial straight air duct (4) is connected to the stepped cross-section auxiliary slot (3), and the upper part of the double radial straight air duct (4) is connected to the slot wedge ventilation duct;

[0012] The rectangular cross-section auxiliary slot ventilation channel (5) is located at a position corresponding to the stator low temperature zone, and the inlet of the rectangular cross-section auxiliary slot ventilation channel (5) is rectangular in shape. From the end of the rotor to the center of the rotor, the rectangular cross-section area remains unchanged.

[0013] The alternating radial air duct (6) is located at a position corresponding to the low temperature zone of the stator, the bottom of the alternating radial air duct (6) is connected to the rectangular cross-section auxiliary slot (5), the upper part of the alternating radial air duct (6) is connected to the slot wedge ventilation duct (6-3), and the alternating radial air duct (6) is formed by alternatingly arranging a single radial straight air duct (6-2) and a double radial straight air duct (6-1).

[0014] Preferably, the annular circumferential air gap partition (8) is made of heat-conductive, electrically non-conductive and magnetically non-conductive material and is welded to the stator core (1) stacked segments.

[0015] Preferably, the stepped shape has at least one step.

[0016] Preferably, the minimum number of the single radial straight air duct (6-2) and the double radial straight air duct (6-1) in the alternating radial air duct (6) is 2.

[0017] Preferably, the single radial straight air duct (6-2) and the double radial straight air duct (6-1) have different radial heights and different circumferential widths.

[0018] It can be seen from the technical solution provided by the above-mentioned embodiments of the present invention that the embodiments of the present invention provide a hybrid ventilation cooling system for a dual-axis excitation motor, which ensures the hydrogen flow in the stator radial ventilation groove, cools the stator winding, and makes the stator winding temperature as evenly distributed as possible along the axial direction; at the same time, it improves the uniformity of flow distribution in the rotor radial ventilation groove, reduces the axial thermal imbalance of the rotor winding, and ultimately reduces the stator and rotor temperatures of the generator, ensuring the safe and reliable operation of large-capacity generators.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description, which will become obvious from the following description, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0021] Figure 1 A schematic diagram of an axial-radial cross-section of a ventilation and cooling system for a dual-axis excitation motor provided by an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of a circumferential air gap partition of a dual-axis excitation motor ventilation and cooling system provided by an embodiment of the present invention;

[0023] Figure 3 A circumferential-radial schematic diagram of a stepped cross-section auxiliary slot and double radial straight air ducts of a dual-axis excitation motor ventilation cooling system provided by an embodiment of the present invention;

[0024] Figure 4 A circumferential-radial schematic diagram of rectangular cross-section auxiliary slots and alternating radial air ducts of a dual-axis excitation motor ventilation and cooling system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0026] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items.

[0027] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0028] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each embodiment does not constitute a limitation on the embodiments of the present invention.

[0029] The structure of a ventilation and cooling system for a dual-axis excitation motor provided by an embodiment of the present invention is as follows: Figure 1 As shown, the structure includes: a stator core 1, a stator radial ventilation groove 2, a stepped cross-section auxiliary slot ventilation duct 3, a double radial straight air duct 4, a rectangular cross-section auxiliary slot ventilation duct 5, an alternating radial air duct 6, an air gap 7 and an annular circumferential air gap partition 8.

[0030] A schematic diagram of a circumferential air gap partition of a dual-axis excitation motor ventilation cooling system provided by an embodiment of the present invention is shown in FIG. Figure 2 As shown. The annular circumferential air gap partition 8 is installed in the stator radial ventilation groove 2, and the thickness of the annular circumferential air gap partition 8 is 1 / 4 of the ventilation groove width, and its width is 1 / 2 of the air gap length. The annular circumferential air gap partition 8 is arranged in the radial ventilation groove of the stator high temperature zone, and the number of the annular circumferential air gap partitions 8 is 1 / 2 of the number of the stator radial ventilation grooves.

[0031] The stator radial ventilation grooves 2 are located between two adjacent stator core 1 stacked segments, and the air gap 7 is located between the stator and the rotor.

[0032] A schematic diagram of a stepped cross-section auxiliary slot and a double radial straight air duct of a dual-axis excitation motor ventilation cooling system provided by an embodiment of the present invention is shown in FIG. Figure 3 The stepped cross-section auxiliary slot ventilation channel 3 is located at a position corresponding to the high temperature zone of the stator, and the entrance of the stepped cross-section auxiliary slot ventilation channel 3 is in a stepped shape, that is, the area is small near the shaft and large near the slot bottom; the stepped cross-section area remains unchanged from the rotor end to the rotor center.

[0033] The double radial straight air duct 4 is two ventilation ducts with long rectangular cross-sections inside the rotor winding, located at the corresponding position of the stator high temperature zone. The bottom of the double radial straight air duct 4 is connected to the stepped cross-section auxiliary slot 3, and the upper part is connected to the slot wedge ventilation duct.

[0034] A schematic diagram of a rectangular cross-section auxiliary slot and alternating radial air duct circumferential-radial of a dual-axis excitation motor ventilation cooling system provided by an embodiment of the present invention is shown in FIG. Figure 4 The rectangular cross-section auxiliary slot ventilation channel 5 is located at a position corresponding to the stator low temperature zone, and the inlet of the rectangular cross-section auxiliary slot ventilation channel 5 is rectangular; from the end of the rotor to the center of the rotor, the rectangular cross-section area remains unchanged.

[0035] The alternating radial air duct 6 is located at a corresponding position of the stator low temperature zone, the bottom of the alternating radial air duct 6 is connected to the rectangular cross-section auxiliary slot 5, and the upper part is connected to the slot wedge ventilation duct 6-3; the alternating radial air duct 6 is formed by alternatingly arranging a single radial straight air duct 6-2 and a double radial straight air duct 6-1.

[0036] The annular circumferential air gap partition 8 is made of heat-conducting, electrically non-conductive and magnetically non-conductive material and is welded on the stator core 1 stacked segments.

[0037] The step shape has at least 1 step number, which can be set preferably.

[0038] The minimum number of the single radial straight air ducts 6 - 2 and the double radial straight air ducts 6 - 1 in the alternating radial air ducts 6 is 2, which can be set by optimization.

[0039] The radial heights and circumferential widths of the single radial straight air duct 6 - 2 and the double radial straight air duct 6 - 1 are different, and can be set by optimization.

[0040] In summary, the embodiment of the present invention provides a dual-axis excitation motor ventilation and cooling system, which can reduce the temperature of the stator and rotor, and make the axial temperature distribution of the stator and rotor uniform. Compared with the traditional steam turbine generator stator, the embodiment of the present invention adds a circular circumferential air gap partition in the high-temperature zone of the stator, which can make the hydrogen coming out of the double radial straight air duct directly enter the radial ventilation groove of the stator without hydrogen crossflow, so that the temperature of the stator winding is as uniform as possible along the axial direction.

[0041] Compared with the traditional rotor structure, the dual-axis excitation motor ventilation cooling system of the present invention adopts two cooling structures, namely, stepped cross-section auxiliary grooves and double radial straight air ducts, and rectangular cross-section auxiliary grooves and alternating radial air ducts, to cool the rotor, thereby improving the uniformity of rotor air volume distribution, effectively reducing the axial temperature of the rotor turn conductor, and avoiding the problem of local overheating of the rotor turn conductor.

[0042] Compared with the traditional structure, the dual-axis excitation motor ventilation and cooling system of the present invention adds an annular circumferential air gap partition, alternating radial air ducts, and stepped cross-section sub-slot ventilation ducts, which can allow the hydrogen coming out of the dual radial straight air ducts to directly enter the stator radial ventilation grooves, thereby making the stator winding temperature as evenly distributed as possible along the axial direction; improving the uniformity of the rotor air volume distribution, effectively reducing the axial temperature of the rotor turn conductor, and avoiding the problem of local overheating of the rotor turn conductor.

[0043] The circumferential air gap partition allows the hydrogen coming out of the double radial straight air duct to directly enter the stator radial ventilation groove without hydrogen crossflow, so that the temperature of the stator winding is as uniform as possible along the axial direction. The stepped cross-section auxiliary slot ventilation duct and the double radial straight air duct can increase the uniformity of air volume distribution, reduce wind resistance, and lower the rotor temperature; the rectangular cross-section auxiliary slot ventilation duct and the alternating radial air duct can also improve the uniformity of air volume distribution and make the rotor axial temperature distribution more uniform.

[0044] Those skilled in the art can understand that the accompanying drawings are only schematic diagrams of an embodiment, and the modules or processes in the accompanying drawings are not necessarily required to implement the present invention.

[0045] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present invention or certain parts of the embodiments.

[0046] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The device and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0047] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A dual-axis excitation motor hybrid ventilation cooling system, characterized in that: include: A stator core (1), a stator radial ventilation groove (2), a stepped cross-section auxiliary slot ventilation duct (3), a double radial straight air duct (4), a rectangular cross-section auxiliary slot ventilation duct (5), an alternating radial air duct (6), an air gap (7) and an annular circumferential air gap partition (8); The annular circumferential air gap partition (8) is installed in the radial ventilation groove (2) of the stator, the thickness of the annular circumferential air gap partition (8) is 1 / 4 of the width of the ventilation groove, and the width is 1 / 2 of the air gap length; the annular circumferential air gap partition (8) is arranged in the radial ventilation groove of the stator high temperature zone, and the number of the annular circumferential air gap partitions (8) is 1 / 2 of the number of the radial ventilation grooves of the stator; The stator radial ventilation groove (2) is located between two adjacent stator core (1) lamination segments, and the air gap (7) is located between the stator and the rotor; The stepped cross-section auxiliary slot ventilation channel (3) is located at a position corresponding to the high temperature zone of the stator. The inlet of the stepped cross-section auxiliary slot ventilation channel (3) is in a stepped shape, that is, the area of ​​the position close to the shaft is small, and the area of ​​the position close to the slot bottom is large. From the end of the rotor to the center of the rotor, the stepped cross-section area remains unchanged. The double radial straight air duct (4) is two ventilation ducts with long rectangular cross-sections inside the rotor winding, located at corresponding positions of the stator high temperature zone, the bottom of the double radial straight air duct (4) is connected to the stepped cross-section auxiliary slot (3), and the upper part of the double radial straight air duct (4) is connected to the slot wedge ventilation duct; The rectangular cross-section auxiliary slot ventilation channel (5) is located at a position corresponding to the stator low temperature zone, and the inlet of the rectangular cross-section auxiliary slot ventilation channel (5) is rectangular in shape. From the end of the rotor to the center of the rotor, the rectangular cross-section area remains unchanged. The alternating radial air duct (6) is located at a position corresponding to the low temperature zone of the stator, the bottom of the alternating radial air duct (6) is connected to the rectangular cross-section auxiliary slot (5), the upper part of the alternating radial air duct (6) is connected to the slot wedge ventilation duct (6-3), and the alternating radial air duct (6) is formed by alternatingly arranging a single radial straight air duct (6-2) and a double radial straight air duct (6-1).

2. The system according to claim 1, characterized in that The annular circumferential air gap partition (8) is made of heat-conductive, non-conductive and non-magnetic material and is welded on the stator core (1) stacked segments.

3. The system according to claim 1, characterized in that The number of steps of the stepped shape is at least one.

4. The system according to claim 1, characterized in that The minimum number of the single radial straight air duct (6-2) and the double radial straight air duct (6-1) in the alternating radial air duct (6) is 2.

5. The system according to claim 1, characterized in that The single radial straight air duct (6-2) and the double radial straight air duct (6-1) have different radial heights and different circumferential widths.

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