Generator base ventilation system

Abstract

The present invention relates to the field of generator ventilation structure, and aims to solve the problem that the existing ventilation structure causes the heat dissipation speed of various parts of the rotor / stator in the axial direction to be uneven, causing thermal stress on the stator / rotor, and provides a generator base ventilation system, including two end shields, an outer skin and a plurality of ring plates. The two end shields are respectively arranged at the two ends of the rotor. A cooling cavity is arranged in the end shield. The outer skin surrounds the outer periphery of the stator and defines an annular cavity between the outer peripheral surface of the stator. The two ends of the annular cavity are respectively connected to the cooling cavity at the corresponding end. A plurality of ring plates are arranged in sequence along the axial direction of the stator to divide the annular cavity into a plurality of sub-cavities arranged in sequence along the axial direction of the stator. The middle sub-cavity located in the axial middle part of each sub-cavity is directly connected to the cooling cavity at the corresponding end through a wind duct connected to one side thereof, and / or is directly connected to the cooling cavity at the corresponding end through a wind duct connected to the other side thereof. The beneficial effect of the present invention is that the axial heat dissipation speed of the stator / rotor is balanced.

Description

Technical Field

[0001] The invention relates to the field of generator ventilation structures, and in particular to a generator base ventilation system. Background Art

[0002] For the steam turbine generator with single wind zone and full radial air outlet, in order to effectively realize the motor cooling, the generator wind path is designed into two centrally symmetrical wind paths, and the coolers are arranged at the four corners of the end shield. The cooling gas is driven by the fans installed at both ends of the rotor, and blown into the center of the generator from the cooler outlets at the steam and excitation ends respectively. The hot air coming out of the radial wind groove of the stator core returns to the steam and excitation end cavities under the action of wind pressure, and the cycle is repeated to form a ventilation path cycle with two ends symmetrical.

[0003] However, in the above method, the heat dissipation rate at the axial center of the stator / rotor is lower than that at both ends, which will cause the stator / rotor to accumulate more heat in the middle and the temperature to be higher than that at both ends, which will cause thermal stress on the stator / rotor and affect the performance of the rotor / stator. In addition, under the accident condition of the cooler, the gas temperature around the motor that has exited the cooler will increase because the heat is not taken away; on the contrary, the gas temperature around the motor that is running the cooler is low, and the direct consequence is that the temperature unevenness at both ends of the generator stator and rotor increases, which may cause the vibration of the unit to deteriorate, bringing risks to the operation of the generator. Summary of the invention

[0004] The present invention aims to provide a generator base ventilation system to solve the problem that the existing ventilation structure causes uneven heat dissipation speeds at different locations in the rotor / stator axial direction, causing thermal stress on the stator / rotor.

[0005] The embodiment of the present invention is achieved as follows:

[0006] A generator base ventilation system includes two end shields, an outer skin and a plurality of ring plates. The two end shields are respectively arranged at the two ends of the rotor. A cooling cavity is arranged in the end shield. The outer skin surrounds the outer circumference of the stator and defines an annular cavity between the outer circumferential surface of the stator. The two ends of the annular cavity are respectively connected to the cooling cavity at the corresponding end. The plurality of ring plates are arranged in sequence along the axial direction of the stator to divide the annular cavity into a plurality of sub-cavities arranged in sequence along the axial direction of the stator. The middle sub-cavity located in the axial middle part of each sub-cavity is directly connected to the cooling cavity at the corresponding end through the air duct connected to one side thereof, and / or is directly connected to the cooling cavity at the corresponding end through the air duct connected to the other side thereof.

[0007] The "direct connection" here means that the gas in the sub-cavity can be directly passed into the cooling cavity through the air duct without passing through the sub-cavity and other sub-cavities between the cooling cavity. In this application, each sub-cavity is divided into end sub-cavities and middle sub-cavities according to position, wherein the end sub-cavity is one or more sub-cavities of the cooling cavity closest to the two ends, and the middle sub-cavity is other sub-cavities between the end sub-cavities at the two ends.

[0008] In this solution, an air duct is provided that directly connects the middle sub-cavity and the cooling cavity, so that the heat of the middle sub-cavity can directly enter the cooling cavity, thereby preventing the heat of the middle sub-cavity from heating the stators and rotors of other sub-cavities it passes through, resulting in the problem that the temperature of the sub-cavity near the cooling cavity is low, while the temperature of other sub-cavities in the middle part is high.

[0009] In the embodiment disclosed in the present application, the end sub-cavities distributed at both ends of the axial direction in each sub-cavity are connected to the cooling cavity at the corresponding end through the air holes opened on the ring plate.

[0010] In the embodiments disclosed in the present application, the air duct passes through each ring plate through which it passes, and forms a sealing fit with the ring plate. The air duct and the ring plate may be arranged in such a way that a through hole is provided on the ring plate to allow the air duct to pass through, and the outer peripheral surface of the air duct and the hole wall of the through hole are sealed to prevent the sub-cavities on both sides of the ring plate from being connected through the air hole.

[0011] In the embodiments disclosed in the present application, the cross-sectional area of ​​the connecting channel between each central sub-cavity and the cooling cavity is positively correlated with the heat dissipation distance of the central sub-cavity. Under this setting, the heat dissipation speed of the central sub-cavities at different positions can be balanced, so that the central sub-cavity with a larger heat dissipation distance can be connected to the cooling cavity through the heat dissipation channel with a larger cross-sectional area for heat dissipation, thereby balancing the heat dissipation efficiency of the central sub-cavities at different positions, improving the uniformity of the temperature of the generator stator and rotor in the axial direction, and avoiding the accumulation of excessive thermal stress at different positions of the local stator and rotor due to temperature difference.

[0012] In the embodiment disclosed in the present application, there are 10 ring plates in total, so as to divide the annular cavity into 9 sub-cavities. The 9 sub-cavities are the first sub-cavity, the second sub-cavity, the third sub-cavity, the fourth sub-cavity, the fifth sub-cavity, the sixth sub-cavity, the seventh sub-cavity, the eighth sub-cavity, and the ninth sub-cavity. Among them, the third sub-cavity, the fourth sub-cavity, the fifth sub-cavity, the sixth sub-cavity, and the seventh sub-cavity are intermediate sub-cavities. The first sub-cavity, the second sub-cavity, the eighth sub-cavity, and the ninth sub-cavity are end sub-cavities. The fifth sub-cavity is connected to the cooling cavity through 6 circumferentially distributed air ducts. The fourth sub-cavity and the sixth sub-cavity are both connected to the cooling cavity through 5 circumferentially distributed air ducts. The third sub-cavity and the seventh sub-cavity are both connected to the cooling cavity through 4 circumferentially distributed air ducts. And the diameters of each air duct are equal.

[0013] In the embodiment disclosed in the present application, the four air ducts of the third sub-cavity / seventh sub-cavity are all connected to the cooling cavity close to one end thereof.

[0014] Two of the five air ducts of the fourth sub-cavity / sixth sub-cavity are connected to the cooling cavity near one end thereof, and the other three are connected to the cooling cavity far from one end thereof. Three of the six air ducts of the fifth sub-cavity are connected to the cooling cavity at one end, and the other three are connected to the cooling cavity at the other end.

[0015] In the embodiment disclosed in the present application, the second sub-cavity / eighth sub-cavity has a wind hole on the ring plate on the cooling cavity side close to the end where the second sub-cavity / eighth sub-cavity is located, so as to connect with the first sub-cavity / ninth sub-cavity. The first sub-cavity / ninth sub-cavity has a wind hole on the ring plate on the cooling cavity side close to the end where the first sub-cavity / ninth sub-cavity is located, so as to connect with the corresponding cooling cavity.

[0016] In the embodiment disclosed in the present application, a cooler for cooling air is provided in the end shield to cool the air from each sub-cavity. An axial flow fan is connected to both ends of the rotor to input the air cooled by the cooler into between the rotor and the stator as the rotor rotates, so as to cool the rotor and the stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings mentioned in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of the structure of the generator base ventilation system in an embodiment of the present invention (arrows are used to show the airflow direction in the figure);

[0019] Figure 2 for Figure 1 An expanded view of the structure in the annular cavity along the circumferential direction (the arrows in the figure show the direction of airflow);

[0020] Figure 3 for Figure 2 The sectional view along the line XX (not expanded, and the center lines AC and BD in the figure divide the circumference into four areas corresponding to Figure 2 The four expanded display areas correspond to the center lines A, B, C, and D).

[0021] Icons: 10-generator base ventilation system; 1-end shield; 3-outer skin; 13-ring plate; 14-rotor; 4-stator; 16-air duct; 2-cooler; 6-axial flow fan; 31-first sub-cavity; 32-second sub-cavity; 33-third sub-cavity; 34-fourth sub-cavity; 35-fifth sub-cavity; 36-sixth sub-cavity; 37-seventh sub-cavity; 38-eighth sub-cavity; 39-ninth sub-cavity; 40-air hole; Q1-cooling cavity; 5-annular cavity; Q3-sub-cavity; Q4-middle sub-cavity; Q5-end sub-cavity. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0025] In the description of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, if the terms "first", "second" and the like appear in the description of the present invention, they are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0026] In addition, if the terms "horizontal" or "vertical" appear in the description of the present invention, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0027] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Example

[0029] See also Figure 1 , Figure 2 and Figure 3 The present embodiment provides a generator base ventilation system 10, which includes two end shields 1, an outer skin 3 and a plurality of ring plates 13. The two end shields 1 are respectively arranged at the two ends of the rotor 14. A cooling cavity Q1 is arranged in the end shield 1. The outer skin 3 surrounds the outer periphery of the stator 4 and defines an annular cavity 5 between the outer peripheral surface of the stator 4. The two ends of the annular cavity 5 are respectively connected to the cooling cavity Q1 at the corresponding end. The plurality of ring plates 13 are arranged in sequence along the axial direction of the stator 4 to divide the annular cavity 5 into a plurality of sub-cavities Q3 arranged in sequence along the axial direction of the stator 4. The middle sub-cavity Q4 located in the axial middle part of each sub-cavity Q3 is directly connected to the cooling cavity Q1 at the corresponding end through the air duct 16 connected to one side thereof, and / or is directly connected to the cooling cavity Q1 at the corresponding end through the air duct 16 connected to the other side thereof. Optionally, a cooler 2 for cooling air is provided in the end shield 1 to cool the air from each sub-cavity Q3. Both ends of the rotor 14 are connected to axial flow fans 6 , so that as the rotor 14 rotates, air cooled by the cooler 2 is input between the rotor 14 and the stator 4 , so as to cool the rotor 14 and the stator 4 .

[0030] The "direct connection" here means that the gas in the sub-cavity Q3 can be directly passed into the cooling cavity Q1 through the air duct 16, without passing through the sub-cavity Q3 and other sub-cavities Q3 between the cooling cavity Q1. In the present application, each sub-cavity Q3 is divided into an end sub-cavity Q5 and a middle sub-cavity Q4 according to the position, wherein the end sub-cavity Q5 is one or more sub-cavities Q3 of the cooling cavity Q1 closest to the two ends, and the middle sub-cavity Q4 is other sub-cavities Q3 between the end sub-cavities Q5 at the two ends.

[0031] In the present solution, by setting up an air duct 16 directly connecting the middle sub-cavity Q4 and the cooling cavity Q1, the heat of the middle sub-cavity Q3 can directly enter the cooling cavity Q1, thereby preventing the heat of the middle sub-cavity Q3 from heating the stator 4 and the rotor 14 at the positions of other sub-cavities Q3 that it passes through, resulting in the problem that the temperature of the sub-cavity Q3 near the cooling cavity Q1 is low, while the temperature of other sub-cavities Q3 in the middle part is high.

[0032] In this embodiment, the air duct 16 passes through each ring plate 13 through which it passes, and forms a sealing fit with the ring plate 13. The air duct 16 and the ring plate 13 may be arranged in such a way that a through hole is provided on the ring plate 13 to allow the air duct 16 to pass through, and a sealing fit is formed between the outer peripheral surface of the air duct 16 and the hole wall of the through hole, so as to prevent the sub-cavities Q3 on both sides of the ring plate 13 from being connected through the air hole 40.

[0033] In this embodiment, the cross-sectional area of ​​the connecting channel between each middle sub-cavity Q4 and the cooling cavity Q1 is positively correlated with the heat dissipation distance of the middle sub-cavity Q4. Under this setting mode, the heat dissipation speed of the middle sub-cavities Q4 at different positions can be balanced, so that the middle sub-cavity Q4 with a larger heat dissipation distance can be connected to the cooling cavity Q1 through the heat dissipation channel with a larger cross-sectional area for heat dissipation, thereby balancing the heat dissipation efficiency of the middle sub-cavities Q4 at different positions, improving the uniformity of the temperature of the generator stator 4 and the rotor 14 in the axial direction, and avoiding the accumulation of excessive thermal stress at different positions of the local stator 4 and the rotor 14 due to temperature difference.

[0034] In this embodiment, there are 10 ring plates 13 in total to divide the annular cavity 5 into 9 sub-cavities Q3. The ring plates 13 at the two ends respectively separate the cooling cavity Q1 and the sub-cavity Q3 at the ends.

[0035] For the convenience of description, the nine sub-cavities Q3 are defined as the first sub-cavity 31, the second sub-cavity 32, the third sub-cavity 33, the fourth sub-cavity 34, the fifth sub-cavity 35, the sixth sub-cavity 36, the seventh sub-cavity 37, the eighth sub-cavity 38, and the ninth sub-cavity 39. Among them, the third sub-cavity 33, the fourth sub-cavity 34, the fifth sub-cavity 35, the sixth sub-cavity 36, and the seventh sub-cavity 37 are intermediate sub-cavities. Among them, the first sub-cavity 31, the second sub-cavity 32, the eighth sub-cavity 38, and the ninth sub-cavity 39 are end sub-cavities Q5; the fifth sub-cavity 35 is connected to the cooling cavity Q1 through six circumferentially distributed air ducts 16. The fourth sub-cavity 34 and the sixth sub-cavity 36 are both connected to the cooling cavity Q1 through five circumferentially distributed air ducts 16. The third sub-cavity 33 and the seventh sub-cavity 37 are both connected to the cooling cavity Q1 through four circumferentially distributed air ducts 16. Optionally, the four air ducts 16 of the third sub-cavity 33 / the seventh sub-cavity 37 are all connected to the cooling cavity Q1 close to one end thereof. Two of the five air ducts 16 of the fourth sub-cavity 34 / the sixth sub-cavity 36 are connected to the cooling cavity Q1 close to one end thereof, and the other three are connected to the cooling cavity Q1 far from one end thereof. Three of the six air ducts 16 of the fifth sub-cavity 35 are connected to the cooling cavity Q1 at one end, and the other three are connected to the cooling cavity Q1 at the other end, and the diameters of the air ducts 16 are equal. Thus, by setting air ducts 16 of the same diameter and different numbers of air ducts 16, it can be used as an implementation method in which the cross-sectional area of ​​the connecting channel between the middle sub-cavity Q4 and the cooling cavity Q1 is positively correlated with the heat dissipation distance of the middle sub-cavity Q4. The air ducts 16 of the same diameter can be conveniently cut from the same pipe material.

[0036] In this embodiment, the end sub-cavities Q5 distributed at both ends of the axial direction in each sub-cavity Q3 are connected to the cooling cavity Q1 at the corresponding end through the air holes 40 opened on the ring plate 13. Among them, the second sub-cavity 32 / eighth sub-cavity 38 is provided with air holes 40 on the ring plate 13 near the cooling cavity Q1 at the end thereof, so as to connect with the first sub-cavity 31 / ninth sub-cavity 39. The first sub-cavity 31 / ninth sub-cavity 39 is provided with air holes 40 on the ring plate 13 near the cooling cavity Q1 at the end thereof, so as to connect with the corresponding cooling cavity Q1.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A generator base ventilation system, characterized in that: include: Two end shields are respectively arranged at two ends of the rotor; a cooling cavity is arranged in the end shields; An outer skin, which surrounds the outer circumference of the stator and defines an annular cavity between the outer circumferential surface of the stator; two ends of the annular cavity are respectively connected to the cooling cavity at the corresponding end; as well as A plurality of annular plates are sequentially arranged at intervals along the axial direction of the stator to divide the annular cavity into a plurality of sub-cavities sequentially arranged along the axial direction of the stator; The middle sub-cavity located in the axial middle part of each sub-cavity is directly connected to the cooling cavity at the corresponding end through the air duct connected to one side thereof, and / or is directly connected to the cooling cavity at the corresponding end through the air duct connected to the other side thereof; The end sub-cavities distributed at both ends of the axial direction in each sub-cavity are connected to the cooling cavity at the corresponding end through the air holes opened on the ring plate; The cross-sectional area of ​​the communication channel between each middle sub-cavity and the cooling cavity is positively correlated with the heat dissipation distance of the middle sub-cavity; There are 10 ring plates in total to divide the annular cavity into 9 sub-cavities; the 9 sub-cavities are the first sub-cavity, the second sub-cavity, the third sub-cavity, the fourth sub-cavity, the fifth sub-cavity, the sixth sub-cavity, the seventh sub-cavity, the eighth sub-cavity and the ninth sub-cavity in sequence; Among them, the third sub-cavity, the fourth sub-cavity, the fifth sub-cavity, the sixth sub-cavity and the seventh sub-cavity are middle sub-cavities; the first sub-cavity, the second sub-cavity, the eighth sub-cavity and the ninth sub-cavity are end sub-cavities; The fifth sub-cavity is connected to the cooling cavity through the six air ducts distributed along the circumferential direction; The fourth sub-cavity and the sixth sub-cavity are both connected to the cooling cavity through the five air ducts distributed along the circumferential direction; The third sub-cavity and the seventh sub-cavity are both connected to the cooling cavity through the four air ducts distributed along the circumferential direction; And the diameters of the air ducts are equal.

2. The generator base ventilation system according to claim 1, characterized in that: The air duct passes through each ring plate it passes through and forms a sealing fit with the ring plates.

3. The generator base ventilation system according to claim 1, characterized in that: The four air ducts of the third sub-cavity / the seventh sub-cavity are all connected to the cooling cavity near one end thereof; Two of the five air ducts of the fourth sub-cavity / the sixth sub-cavity are connected to the cooling cavity close to one end thereof, and the other three are connected to the cooling cavity far from one end thereof; Three of the six air ducts of the fifth sub-cavity are connected to the cooling cavity at one end, and the other three are connected to the cooling cavity at the other end.

4. The generator base ventilation system according to claim 3, characterized in that: A wind hole is provided on the ring plate on the cooling cavity side of the second sub-cavity / the eighth sub-cavity close to the cooling cavity at one end thereof, so as to communicate with the first sub-cavity / the ninth sub-cavity; The first sub-cavity / the ninth sub-cavity has an air hole on the ring plate on one side of the cooling cavity close to the end where the first sub-cavity / the ninth sub-cavity is located, so as to be connected with the corresponding cooling cavity.

5. The generator base ventilation system according to claim 1, characterized in that: A cooler for cooling air is provided in the end shield to cool the air from each sub-cavity; The two ends of the rotor are respectively connected with axial flow fans, so as to input the air cooled by the cooler into between the rotor and the stator as the rotor rotates, so as to cool the rotor and the stator.

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