CN217586186U - Leakage detection device for stator of wind driven generator - Google Patents

Abstract

The utility model relates to a leak hunting device for aerogenerator stator, aerogenerator include stator and the rotor of each other sealed isolation, and the stator includes stator oil pocket (1) and sets up in stator oil pocket with the stator winding of oil cooling, and the rotor setting is outside the stator oil pocket, and the stator oil pocket has leak hunting hole (4), and the stator is equipped with the leak hunting point that remains to be spouted the helium and comes the leak hunting, and leak hunting device includes: the helium mass spectrometer leak detector is used for being connected to a leak detection hole through a pipeline (6), a first valve (7) used for enabling the pipeline to be communicated with or blocked from a stator oil cavity is arranged on one side, close to the leak detection hole, of the pipeline, and a second valve (8) used for enabling the pipeline to be communicated with or blocked from the helium mass spectrometer leak detector is arranged on one side, close to the helium mass spectrometer leak detector; a vacuum pump disposed on the pipeline to evacuate the stator oil cavity; and a vacuum detection device (11) arranged on the pipeline at one side of the vacuum pump close to the leak detection hole. The utility model provides the high leak hunting precision and the cost is reduced.

Description

Leakage detection device for stator of wind driven generator

Technical Field

The utility model relates to a leak hunting device for aerogenerator stator.

Background

Under the large background of "carbon peak" and "carbon neutralization", a higher demand has been placed on wind power generation technology for clean power sources. The semi-direct-drive technology integrating the advantages of the high-speed gear transmission technology and the permanent magnet direct-drive technology has wide development space in the fields of large megawatt units and offshore wind power. The semi-direct-drive transmission chain technology has the characteristics of high reliability, high performance, compact structure and the like, wherein particularly, an oil-cooled medium-speed permanent magnet synchronous wind driven generator adopts a brand-new cooling mode, and because a winding is always soaked in circulating cooling oil, heat exchange can be directly completed, so that the cooling performance is excellent. But also put forward higher requirement to the leakproofness of stator oil pocket simultaneously, must carry out strict leakproofness detection before the generator leaves the factory.

Because the stator of the medium-speed permanent magnet synchronous wind driven generator adopts an oil cooling mode for the first time, no test method is used for detecting the tightness of the stator of the generator at present. If the stator is verified to be airtight by soaking, a 6 cubic meter soaking pool is needed. On one hand, the tightness of the stator is not easy to judge by observing the formation condition of bubbles; on the other hand, there is a risk of immersion water entering the stator windings.

For this reason, there is a need for improved leak detection apparatus for the above and other types of oil-cooled wind turbine stators.

SUMMERY OF THE UTILITY MODEL

For overcoming at least one defect of prior art, the utility model provides a simplify the structure, improve the leak hunting device for aerogenerator stator of leak hunting precision.

According to an aspect of the utility model, a leak hunting device for aerogenerator stator is provided, aerogenerator is including stator and the rotor of each other seal isolation, the stator includes the stator oil pocket and sets up stator winding in order to cool with oil in the stator oil pocket, the rotor sets up outside the stator oil pocket, the stator oil pocket has the leak hunting hole, the stator is equipped with the leak hunting point that remains to be spouted the helium and leak hunting, leak hunting device includes: the helium mass spectrometer leak detector is connected to the leak detection hole through a pipeline, a first valve used for enabling the pipeline to be communicated with or blocked from the stator oil cavity is arranged on one side, close to the leak detection hole, of the pipeline, and a second valve used for enabling the pipeline to be communicated with or blocked from the helium mass spectrometer leak detector is arranged on one side, close to the helium mass spectrometer leak detector; a vacuum pump disposed on the pipe to evacuate the stator oil chamber; and the vacuum detection device is arranged on one side, close to the leak detection hole, of the vacuum pump on the pipeline.

According to one embodiment, the vacuum pump comprises a molecular vacuum pump integrated with the helium mass spectrometer leak detector.

According to one embodiment, the vacuum pump comprises a primary vacuum pump disposed between the first valve and the second valve, the primary vacuum pump configured to evacuate the stator oil chamber prior to operation of the molecular vacuum pump.

According to one embodiment, the leak detection means comprise a helium tank and a helium spray gun connected to the helium tank, and/or the vacuum detection means comprise a pressure gauge or a vacuum gauge.

According to one embodiment, the leak detection point is provided at a sealing surface between the stator and the rotor and outside the stator, at which sealing surface between the stator and the rotor a cylindrical seal separating the stator oil chamber and the rotor forms a seal with a rotor end cover at two sides axially opposite to each other.

According to one embodiment, the leak detection points include a plurality of leak detection points distributed from top to bottom in a leak detection state, and the detection device is configured to detect the plurality of leak detection points in order from top to bottom.

According to one embodiment, the leak detection orifice is selected from one or more orifices already present on the stator oil chamber, said leak detection orifice being located at or near the upper side of the stator oil chamber in the leak detection state.

According to one embodiment, the vacuum detection device has one of the following features: the vacuum detection device is disposed between the first valve and the second valve and connected to the pipeline at the same connection position as the vacuum pump, the vacuum detection device being configured to detect a vacuum level in the pipeline when the first valve and the second valve are closed and detect a vacuum level in the stator oil chamber when the first valve is opened; or the vacuum detection device is arranged between one end of the pipeline close to the leak detection hole and the first valve and is configured to detect the vacuum degree in the stator oil cavity when the first valve is opened.

According to one embodiment, the helium mass spectrometer leak detector is an auto-calibration leak detector or is calibrated by a standard leak orifice provided in the piping.

According to one embodiment, the wind generator is a medium speed permanent magnet synchronous wind generator and/or the stator windings are cooled by immersion in circulating oil.

The utility model discloses an adopt helium mass spectrum leak hunting technique to jet-propelled detection leakproofness to oil-cooled aerogenerator stator, can confirm accurately that the leakage point is leaked, improved the leak hunting precision when simplifying the leak hunting device greatly to leak hunting cost has been reduced through reducing the helium quantity.

Drawings

Further features and advantages of the present invention will be apparent from the description and drawings, which illustrate, in detail, various embodiments according to the present invention.

Fig. 1 is a schematic plan view of a leak detection apparatus for a stator of a wind turbine according to an embodiment of the present invention.

Fig. 2 schematically shows a leak detection point outside a wind turbine according to an embodiment of the present invention.

Fig. 3 schematically shows a partial sealing structure inside a wind turbine according to an embodiment of the present invention.

Detailed Description

Specific embodiments and modifications thereof according to the present invention will be described in detail below with reference to the accompanying drawings.

For convenience in description, spatially relative terms "inner", "outer", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", and the like, are used herein to define various components and their connections. This is not intended to be limiting. These relative spatial relationships may also be reversed or changed as the orientation of the components is changed without affecting the scope of the present invention.

Fig. 1 is a schematic plan view of a leak detection apparatus for a stator of a wind turbine according to an embodiment of the present invention. The leak detection device is used for detecting potential leakage points outside the wind driven generator shown in FIG. 2 and inside the wind driven generator shown in FIG. 3.

Fig. 2 schematically illustrates a leak detection point 100 external to a wind turbine according to an embodiment of the present invention. One side of the generator (the left side in fig. 2) is the drive end for being driven by wind power, for example, by the blade rotor driving the gearbox and thus the generator to operate, and the other side (the right side in fig. 2) is the driven end for outputting electrical power. Due to the assembly of the generator itself or the connection to the outside, etc., several assembly points or connection points are formed outside the generator, and the sealing surfaces at these assembly points or connection points become potential leakage points, so leak detection is required to ensure the sealing performance.

Fig. 3 schematically shows a partial sealing structure inside a wind turbine according to an embodiment of the present invention. The wind power generator includes a stator located radially outside (upper side in fig. 3) the generator and a rotor located radially inside (lower side in fig. 3) the generator, the stator and the rotor being sealed from each other. As shown in fig. 3, a stator oil chamber 1 is provided in the stator, and a stator winding (not shown) wound around the stator core is immersed in the stator oil chamber 1 to be cooled by the circulating oil. The stator oil chamber 1 is sealed from the rotor by a cylindrical stator seal 2, the stator seal 2 surrounding the rotor to radially isolate the stator from the rotor and forming a seal with the rotor end cover 3 at axially opposite ends, for example by providing an annular seal ring or gasket or the like (not shown) between the stator seal 2 and the rotor end cover 3.

Although the stator is described above as being located radially outside the rotor, it is contemplated that the stator may be located radially inside the rotor, depending on the different configurations inside the generator. In addition, the sealing between the stator oil chamber 1 and the rotor is not limited to the sealing between the stator seal 2 and the rotor end cover 3, and the sealing between the stator seal 2 and the generator housing may be designed as required.

Regardless of which component of the generator the stator seal 2 forms a seal with, the seal becomes a potential leak point and therefore leak detection is also required to ensure sealing performance.

Returning to fig. 1, a leak detection apparatus according to an embodiment of the present invention is connected to a leak detection hole 4 of a stator oil chamber 1. The leak detection hole 4 can directly utilize the original hole on the stator oil cavity 1 without additionally processing the leak detection hole special for leak detection. Since the leak detection apparatus uses helium gas to detect through the leak detection hole 4, which tends to flow upward in the stator oil chamber 1, a hole at or near the upper side of the stator oil chamber 1 in the leak detection state, for example, a hole where the stator output terminal (main terminal box) is located, may be selected as the leak detection hole 4 in order to accurately determine the leak position. In addition, in order to improve leak detection efficiency, one or more leak detection holes 4 may be provided, and in the case of a plurality of leak detection holes 4, a plurality of branch pipes may be provided from the pipe 6 of the leak detection apparatus to communicate with the respective leak detection holes 4.

As shown in fig. 1, the leak detection apparatus includes a helium mass spectrometer leak detector 5, and the helium mass spectrometer leak detector 5 is connected to a leak detection hole 4 of a stator oil chamber 1 via a piping 6 to detect the sealing performance of the stator oil chamber 1. The conduit 6 may be a metal bellows to improve flexibility of connection, however any other suitable form of tube may be used. A first valve 7 is arranged on the side of the pipeline 6 close to the leak detection hole 4, and the first valve 7 is used for communicating or blocking the pipeline 6 with the stator oil cavity 1. On the other side of the line 6, which is close to the helium mass spectrometer leak detector 5, a second valve 8 is provided, which second valve 8 serves to connect or block the helium mass spectrometer leak detector 5 to the line 6, i.e. to connect or disconnect the helium mass spectrometer leak detector 5 from the line 6.

In the example shown in fig. 1, the helium mass spectrometer leak detector 5 itself is integrated with a molecular vacuum pump 9, which molecular vacuum pump 9 is used to evacuate the stator oil chamber 1. However, the molecular vacuum pump 9 may also be a separate vacuum pump from the helium mass spectrometer leak detector 5. In addition, in the case of a large volume of the generator stator oil chamber 1, in order to increase the efficiency of the vacuum pumping, it is advantageous to provide an additional primary vacuum pump 10 on the line 6 between the first valve 7 and the second valve 8. The primary vacuum pump 10 is used for primarily vacuumizing the stator oil cavity 1, and when the vacuum in the stator oil cavity 1 reaches a certain degree, the stator oil cavity 1 is continuously vacuumized by the molecular vacuum pump 9 until the degree required by leak detection is reached.

The helium mass spectrometer leak detector 5 may be an automatic calibration leak detector, or may be calibrated by providing a standard leak hole in the piping 6.

In order to detect the vacuum level in the stator oil chamber 1, a vacuum detection device 11, such as a pressure detection device for measuring pressure, such as a pressure gauge, a pressure sensor, or the like, or a vacuum gauge for measuring the vacuum level, or the like, is further provided on the pipe 6. In the example shown in fig. 1, the vacuum detection means 11 are arranged between the first valve 7 and the second valve 8, advantageously connected to the line 6 at the same position as the primary vacuum pump 10, to reduce the number of connections in the line 6 and the risk of leaks in the line 6. When the first valve 7 and the second valve 8 are closed and the pipeline 6 is vacuumized, the vacuum detection device 11 can detect whether the vacuum degree in the pipeline 6 meets the requirement or not so as to judge whether the pipeline 6 has leakage or not. When the first valve 7 is opened to vacuumize the stator oil cavity 1, the vacuum detection device 11 can detect whether the vacuum degree in the stator oil cavity 1 reaches a required value. However, it is also conceivable to detect the vacuum level in the stator oil chamber 1 directly after the evacuation of the stator oil chamber 1, without detecting the vacuum level in the line 6 beforehand. In this case, the position of the vacuum detection device 11 is not limited to be located between the first valve 7 and the second valve 8, but may be located between the first valve 7 and the end of the line 6 close to the leak detection hole 4. It is conceivable as long as a vacuum detection device 11 is located on the line 6 between the vacuum pump (molecular vacuum pump 9 or primary vacuum pump 10) and the leak detection opening 4 in order to detect the vacuum level in the stator oil chamber 1 via the leak detection opening 4.

The leak detection apparatus may further include a gas injection device for injecting a tracer gas helium gas to a potential leak point (i.e., leak detection point 100) of the stator of the generator, the gas injection device including, for example, a helium gas tank 12 containing helium gas and a helium gas spray gun 13 connected to the helium gas tank 12. The gas injection means may also comprise any other suitable source of helium and an injector. In the leakage detection process, the helium spray gun 13 sprays helium to potential leakage points of the generator stator, if leakage exists, the helium enters the stator oil cavity 1 and is pumped to the helium mass spectrometer leak detector 5 to be detected, and therefore whether the stator needs to be sealed again or not is judged according to the leakage rate displayed by the helium mass spectrometer leak detector 5. Compared with a mode of filling helium into the stator oil cavity 1 to detect helium leaked to the outside of the stator, the mode of injecting helium to the potential leakage detection point 100 to detect leakage is adopted, and particularly under the condition that the volume of the stator oil cavity 1 is large, the purpose of leakage detection can be achieved by using the minimum amount of helium, so that the detection cost is reduced.

The operation of the detection apparatus shown in fig. 1 will be described below by way of example.

(1) Sample preparation

Because helium testing is performed by helium passing through a leak hole, if deposits are present on the sealing surface of the part being tested, the leak hole may become temporarily blocked or may not seal properly, thereby affecting the test results. Therefore, before the generator is assembled, the sealing surface of the tested piece must be thoroughly cleaned, and the interior of the equipment must be thoroughly dried by using a hot air gun.

As shown in fig. 1, a generator stator oil cavity 1 sample is prepared (for example, by using a placement state that a driving end is arranged at the lower part and a non-driving end is arranged at the upper part in an assembly process), and a generator stator oil cavity 1 to be subjected to leak detection is connected with a helium mass spectrometer leak detector 5 (including a molecular vacuum pump 9) and a primary vacuum pump 10 through a testing port (such as a main junction box) by using a metal corrugated pipe and a valve (because the volume of a tested piece, namely the generator stator oil cavity 1, is larger, an additional primary vacuum pump 10 is required to work together to improve the efficiency).

(2) Test procedure

a) The leak detector is arranged: and after the computer is started, setting parameters through a control panel.

b) Detecting and completing calibration by the leak detector: and (4) selecting a vacuum method for detection, setting the detection to be automatic, and executing automatic calibration of the leak detector.

c) And recording the temperature, humidity and air pressure of the measuring environment.

d) As shown in fig. 1, the first valve 7 and the second valve 8 are closed, the connected metal corrugated pipe is vacuumized by the primary vacuum pump 10, and the joint is checked by the vacuum detection device 11, so that the sealing performance of the corrugated pipe is ensured to be good.

e) Then, the first valve 7 is opened, and the generator stator oil cavity 1 is subjected to primary vacuum pumping by using the primary vacuum pump 10. And when the vacuum degree of the stator oil cavity 1 is smaller than the first threshold, opening a second valve 8 so as to further utilize a molecular vacuum pump 9 to continuously vacuumize the generator stator oil cavity 1 until the vacuum degree of the stator oil cavity 1 is reduced to a second threshold meeting the leak detection requirement.

f) All leak points 100 outside the generator stator, including the blind cover and the seals at the end covers, are first inspected.

g) The valve pressure of helium tank 12 is adjusted to a predetermined value and helium tracer gas is injected at a predetermined rate or flow rate into leak detection point 100 shown in fig. 2 using helium spray gun 13. And observing the leakage rate displayed on the leak detector, and if the leakage rate is greater than a preset threshold value, resealing until the leakage point meets the requirement of the leakage rate.

h) Secondly, the leak detection is critical, namely the seal between the stator seal can (i.e. stator seal 2) and the rotor end cover 3. The sequence of testing is to start with the non-drive end above and then the drive end below to avoid degrading the leak location accuracy due to helium up-flow.

i) An operator enters the interior of the generator stator, adjusts the valve pressure of the helium tank 12 to a predetermined value, and sprays helium at a predetermined rate or flow rate at the drive side seal and the non-drive side seal between the stator seal pot and the rotor cover 3 using a helium spray gun 13.

j) Another operator standing outside the stator is paying attention to observe the leak rate displayed on the leak detector. If the leak rate meets or exceeds a predetermined threshold, a signal is immediately given, while an operator inside the stator immediately shuts off the helium spray gun 13 and marks the leak on the stator seal pot.

k) When a leakage point is detected, the machine is disassembled to check whether deposits exist at the leakage point, whether a sealing ring is broken, whether machining defects exist on the sealing surfaces of the rotor end cover 3 and the stator sealing tank, and the like, and the sealing is performed again according to a specified bolt fastening mode.

l) repeating the above steps c) to k) until the leak rate at all leak detection points 100 does not exceed a predetermined threshold, i.e. is acceptable.

In the above detection process, various parameters including the vacuum degree of the stator oil chamber 1, the valve pressure of the helium tank 12, the speed or flow rate of the helium spray gun 13, the leak rate threshold value, and the like can be set by computer simulation or empirical values.

In addition, because the generator stator has a plurality of leak detection points 100, during the leak detection process, detection can be performed in the order from top to bottom so as to accurately determine the leak detection points and improve the leak detection precision.

The utility model discloses an adopt helium mass spectrum leak hunting technique to come jet-propelled detection leakproofness to the cold aerogenerator stator of oil, can confirm the leakage point accurately, improved the leak hunting precision greatly when simplifying the leak hunting device to leak hunting cost has been reduced through reducing the helium quantity.

While specific embodiments in accordance with the invention have been described in detail with reference to the accompanying drawings, the invention is not limited to the specific structure described above, but covers various modifications and equivalent features. Various changes may be made by those skilled in the art without departing from the scope of the invention.

Claims (10)

1. Leak detection apparatus for a stator of a wind turbine generator, the wind turbine generator comprising a stator and a rotor hermetically isolated from each other, the stator comprising a stator oil chamber (1) and a stator winding arranged inside the stator oil chamber (1) to be cooled with oil, the rotor being arranged outside the stator oil chamber (1), the stator oil chamber (1) having a leak detection hole (4), the stator being provided with a leak detection point (100) to be leak-detected by spraying helium gas, the leak detection apparatus comprising:

the helium mass spectrometer leak detector is used for being connected to the leak detection hole (4) through a pipeline (6), a first valve (7) used for enabling the pipeline (6) to be communicated with or blocked from the stator oil cavity (1) is arranged on one side, close to the leak detection hole (4), of the pipeline (6), and a second valve (8) used for enabling the pipeline (6) to be communicated with or blocked from the helium mass spectrometer leak detector (5) is arranged on one side, close to the helium mass spectrometer leak detector (5);

the vacuum pump is arranged on the pipeline (6) and used for vacuumizing the stator oil cavity (1); and

and a vacuum detection device (11) is arranged on the pipeline (6) and is arranged on one side of the vacuum pump close to the leakage detection hole (4).

2. Leak detection apparatus as claimed in claim 1, characterized in that the vacuum pump comprises a molecular vacuum pump (9) integrated with the helium mass spectrometer leak detector (5).

3. Leak detection apparatus according to claim 2, wherein the vacuum pump comprises a primary vacuum pump (10) disposed between the first valve (7) and the second valve (8), the primary vacuum pump (10) being configured to evacuate the stator oil chamber (1) prior to operation of the molecular vacuum pump (9).

4. Leak detection apparatus according to claim 1, characterized in that the leak detection apparatus comprises a helium tank (12) and a helium spray gun (13) connected to the helium tank (12), and/or the vacuum detection apparatus (11) comprises a pressure gauge or a vacuum gauge.

5. Leak detection apparatus according to claim 1, characterised in that the leak detection point (100) is arranged at a sealing surface between the stator and the rotor and outside the stator, at which sealing surface a cylindrical seal separating the stator oil chamber (1) and the rotor forms a seal with a rotor end cover (3) at two axially opposite sides to each other.

6. Leak detection apparatus according to claim 1, characterized in that the leak detection point (100) comprises a plurality of leak detection points (100) distributed from top to bottom in the leak detection state, the detection apparatus being configured to detect the plurality of leak detection points (100) in order from top to bottom.

7. Leak detection apparatus as claimed in claim 1, characterized in that the leak detection opening (4) is selected from one or more openings already present in the stator oil chamber (1), the leak detection opening (4) being located on the upper side of the stator oil chamber (1) or close to the upper side of the stator oil chamber (1) in the leak detection state.

8. Leak detection apparatus according to claim 1, characterized in that the vacuum detection means (11) has one of the following features:

the vacuum detection device (11) is arranged between the first valve (7) and the second valve (8) and is connected to the pipeline (6) at the same connection position as the vacuum pump, the vacuum detection device (11) is configured to detect the vacuum degree in the pipeline (6) when the first valve (7) and the second valve (8) are closed, and detect the vacuum degree in the stator oil cavity (1) when the first valve (7) is opened; or alternatively

The vacuum detection device (11) is arranged between one end of the pipeline (6) close to the leakage detection hole (4) and the first valve (7) and is configured to detect the vacuum degree in the stator oil cavity (1) when the first valve (7) is opened.

9. Leak detection apparatus according to claim 1, characterized in that the helium mass spectrometer leak detector (5) is an autocalibration leak detector or is calibrated by means of a standard leak orifice provided on the line (6).

10. Leak detection apparatus according to any of claims 1 to 9, wherein the wind generator is a medium speed permanent magnet synchronous wind generator and/or the stator windings are cooled by immersion in circulating oil.

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