Contact type blade tip clearance measuring device and method

Abstract

The invention provides a contact type blade tip clearance measuring device and method, the measuring device is arranged between a stator casing and a rotor blade tip, the measuring device comprises a body, the body comprises a connecting end and a measuring end, the connecting end is connected with the stator casing, and the measuring end faces the rotor blade tip; the thickness of the body increases gradually in the direction from the stator casing to the blade tip of the rotor blade. According to the contact type blade tip clearance measuring device, the thickness of the body increases gradually in the direction from the stator casing to the rotor blade tip, during test run, the rotor blade tip scrapes and abrades the body, after test run, the blade tip clearance can be calculated by observing the thickness of the body through borescope equipment, and the blade tip clearance can be calculated by obtaining the whole-circle blade tip clearance. And the eccentric state of the rotor and the stator can be better evaluated.

Description

Technical Field

[0001] This invention relates to the field of blade tip clearance measurement technology, and specifically to a contact-type blade tip clearance measurement device and method. Background Technology

[0002] Compressor blade tip clearance is the gap between the rotor blade tip and the stator casing. This clearance meets both performance and safety requirements. If the clearance is too small, the blade tip will rub against the stator casing; if the clearance is too large, the compressor performance will decrease.

[0003] Furthermore, blade tip clearance is related to many factors, including cold and hot deformation, bearing clearance, dimensional tolerances, and geometric tolerances. The degree of influence of each factor is difficult to obtain accurately through calculation, making clearance design quite challenging. During the product development stage, the actual clearance during actual testing is often used to continuously refine the clearance and ultimately obtain the blade tip clearance that meets product requirements. This necessitates high-precision clearance measurement methods.

[0004] During the research and development stage, in order to avoid severe rubbing between the rotor and stator caused by inaccurate clearance design, an easy-wear coating will be applied to the casing at the position corresponding to the rotor blade tip.

[0005] When the blade tip clearance is designed to be too small, the rotor blade tip is scraped to remove the wear-prone coating, thus ensuring test safety. Currently, the main method for measuring clearance is the blade tip clearance sensor, but the accuracy of the clearance sensor is often only ±0.1mm due to the influence of calibration and installation. During high-pressure testing, the clearance sensor is at risk of failure due to the high temperature and pressure; the number of sensors that can be arranged circumferentially is limited by space constraints; and the sensor equipment is expensive.

[0006] Based on this, the inventors of this application propose a contact-type blade tip clearance measuring device and method to solve the above-mentioned technical problems. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art in measuring blade tip clearance, which is difficult and costly, and to provide a contact-type blade tip clearance measuring device and method.

[0008] The present invention solves the above-mentioned technical problems through the following technical solution:

[0009] This invention provides a contact-type blade tip clearance measuring device, characterized in that the measuring device comprises:

[0010] The body includes a connecting end and a measuring end, wherein the connecting end is connected to the stator casing, and the measuring end faces the tip of the rotor blade; wherein,

[0011] The thickness of the body increases along the direction from the stator casing to the tip of the rotor blade.

[0012] According to one embodiment of the present invention, the body is an easy-wear coating.

[0013] According to one embodiment of the present invention, the connecting end of the body is coated onto the stator casing.

[0014] According to one embodiment of the present invention, the body has a stepped structure along the direction from the stator casing to the tip of the rotor blade.

[0015] According to one embodiment of the present invention, each step surface of the stepped body is arranged parallel to the top surface of the rotor blade tip.

[0016] According to one embodiment of the present invention, the body has an adjacent first step and a second step along the direction from the stator casing to the rotor blade tip, and the first step and the second step each include a plurality of steps in the direction away from each other.

[0017] The first stepped portion and the second stepped portion are symmetrically arranged along their adjacent surfaces.

[0018] According to one embodiment of the present invention, the body is provided with a plurality of measuring sections along the axial direction of the stator casing or the rotor blade tip.

[0019] According to one embodiment of the present invention, each of the measuring units is arranged in a stepped manner along the direction from the stator casing to the tip of the rotor blade.

[0020] According to one embodiment of the present invention, at least one of the measuring parts includes a first stepped part and a second stepped part arranged symmetrically.

[0021] The present invention also provides a contact-type blade tip clearance measurement method, which employs the contact-type blade tip clearance measurement device described above, and the measurement method includes:

[0022] Step 1: Apply the coating to the end face of the stator casing facing the rotor blades;

[0023] Step 2: When the rotor blades are assembled with the stator casing and they rotate relative to each other, the rotor blades grind the body.

[0024] Step 3: Use a borescope with the borescope holes opened on the stator casing to observe the thickness of the body and obtain the blade tip clearance.

[0025] The positive and progressive effects of this invention are as follows:

[0026] The contact-type blade tip clearance measuring device of the present invention has a body whose thickness increases gradually along the direction from the stator casing to the rotor blade tip. During the test run, the rotor blade tip scrapes against the body. After the test run, the thickness of the body can be observed using a borescope to calculate the blade tip clearance. By obtaining the blade tip clearance of the entire circumference, the eccentricity of the rotor and stator can be better evaluated. Attached Figure Description

[0027] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0028] Figure 1 This is a schematic diagram of one embodiment of the contact-type blade tip clearance measuring device of the present invention;

[0029] Figure 2 This is a schematic diagram of another embodiment of the contact-type blade tip clearance measuring device of the present invention;

[0030] Figure 3 This is a schematic diagram of another embodiment of the contact-type blade tip clearance measuring device of the present invention;

[0031] Figure 4 This is a flowchart of the contact-type blade tip clearance measurement method of the present invention.

[0032] 1. Main body; 11. Connecting end; 12. Measuring end; 13. First step section; 14. Second step section; 15. Measuring section;

[0033] 2. Stator casing; 21. Probe hole;

[0034] 3. Rotor blade tips. Detailed Implementation

[0035] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0037] Please refer to Figures 1 to 4This invention proposes a contact-type blade tip clearance measuring device, disposed between the stator casing 2 and the rotor blade tip 3. The measuring device includes a body 1, which includes a connecting end 11 and a measuring end 12. The connecting end 11 is connected to the stator casing 2, and the measuring end 12 faces the rotor blade tip 3. The thickness of the body 1 increases gradually along the direction from the stator casing 2 to the rotor blade tip 3.

[0038] The thickness of the body 1 increases gradually along the direction from the stator casing 2 to the rotor blade tip 3. During the test run, the rotor blade tip scrapes against the body 1. After the test run, the thickness of the body 1 can be observed using a borescope to calculate the blade tip clearance. By obtaining the blade tip clearance around the entire circumference, the eccentricity between the rotor and the stator can be better evaluated.

[0039] Specifically, the body 1 has an easy-wear coating. The connecting end 11 of the body 1 is connected to the stator housing 2. The connection method can be adhesive bonding or other methods, which are not limited here.

[0040] It can be seen that the main body 1 is arranged in a continuous ring around the stator casing 2 at one end facing the rotor blade tip 3.

[0041] The connecting end 11 of the body 1 is coated with the surface of the stator casing 2 facing the rotor blade tip 3, and the projection of the body 1 along the radial direction of the rotor blade falls on at least the outer peripheral surface of the rotor blade tip. This ensures that when the rotor blade rotates relative to the stator casing 2, the rotor blade tip 3 can form a scraping with the body 1, so as to facilitate the subsequent clearance calculation.

[0042] Reference Figure 1 The main body 1 has a stepped structure along the direction from the stator casing 2 to the rotor blade tip 3.

[0043] Specifically, the stepped structure can be multi-step, and the surface of the multi-step can be a plane or a rotating surface.

[0044] Moreover, the height of each step can be set to a certain value. Thus, during the test run, the height of the remaining step can be calculated after each step of rotor blade wears down, making it very convenient to calculate the blade tip clearance.

[0045] Specifically, the stator casing 2 is provided with a borehole 21. After the test run, the number of remaining steps can be quickly determined by using a borehole device to observe through the borehole 21.

[0046] For example, the height of each step is 0.05 to 0.1 mm. After the test run, the number of remaining steps can be used to intuitively determine the tip clearance during the test.

[0047] Specifically, taking 0.1mm as an example, the total height of the main body 1 along the height direction from the stator casing 2 to the rotor blade tip 3 is 0.3mm. After the test run, it was confirmed that it was worn by one step, so the blade tip clearance in the test was 0.2mm.

[0048] The step design eliminates the need for calculations, allowing for quick determination of the blade tip clearance during the experiment through observation.

[0049] Please refer to Figure 2 The main body 1 has an adjacent first step 13 and second step 14 along the direction from the stator casing 2 to the rotor blade tip 3. The first step 13 and the second step 14 each include multiple steps in the direction away from each other. The first step 13 and the second step 14 are symmetrically arranged along the planes that are connected to each other.

[0050] That is, the overall shape of the main body 1 is conical, and both sides of the cone are in the form of steps.

[0051] Specifically, the first step 13 and the second step 14 are integrated into one unit, which is not limited here.

[0052] The symmetrical arrangement of the first step 13 and the second step 14 allows for the evaluation of the axial uniformity of the blade tip clearance by observing their state after the test run, thereby guiding the design of the rotor blade tip tilt angle.

[0053] For example, if the first step section 13 and the second step section 14 are in the same state on both sides after the test run, then the blade tip clearance is uniform in the axial direction and the rotor blade tilt angle is reasonably designed.

[0054] If the scraping conditions of the first step 13 and the second step 14 are different after the test run, it means that the blade tip clearance is not uniform in the axial direction, and the blade tip tilt angle of the rotor blade can be optimized.

[0055] Reference Figure 3 The main body 1 is provided with multiple measuring parts 15 along the axial direction of the stator casing 2 or the rotor blade tip 3.

[0056] Multiple measuring units 15 can be used in conjunction with each other to determine the scraping condition at different positions along the axial direction of the rotor blade tip 3.

[0057] That is, at the mating gap between the rotor blade tip 3 and the stator casing 2, multiple measuring sections 15 can be arranged at axial intervals. The measuring sections 15 can correspond to the stepped structure described above, or other suitable structural types can be adopted. This arrangement allows for a better evaluation of the axial gap distribution of the rotor blade or stator casing.

[0058] It is understood that the shape of the body 1 can also be selected from other optional shapes such as a triangular non-stepped shape, a cylindrical non-stepped shape, or a conical non-stepped shape, so that the height of the body 1 can be measured after the test drive. This embodiment is also within the protection scope of the present invention, and will not be elaborated further here.

[0059] In some other embodiments, the body 1 may also employ a symmetrically distributed first step portion 13 and second step portion 14, and a combination of at least two measuring portions 15, so as to determine the axial clearance distribution of the stator casing 2 or rotor blades.

[0060] Please follow Figure 4 The present invention also proposes a contact-type blade tip clearance measurement method, which employs the above-mentioned contact-type blade tip clearance measurement device, and the measurement method includes:

[0061] S1. Apply the coating to the end face of the stator casing facing the rotor blades.

[0062] It can be seen that the connecting end of the body is installed to one end face of the rotor blade after the stator casing is wiped with adhesive.

[0063] In some other alternative implementations, other connection methods such as snap-fit ​​can also be used, which are not limited here.

[0064] S2. When the rotor blades are assembled with the stator casing and rotate relative to each other, the rotor blades grind the body.

[0065] In other words, the rotor blades are operated according to actual requirements, and the operating state of the rotor blades can be adjusted to meet the needs of different working conditions.

[0066] In the initial state, the height of the body should be as high as possible to avoid the rotor blades not scraping against the body during operation, which would affect the test.

[0067] S3. Using a borescope and the boreholes on the stator casing, observe the thickness of the blade body to obtain the blade tip clearance.

[0068] The stator casing has a borehole, through which the measuring end of the borehole probe can be used to observe the thickness of the body, thus obtaining the minimum tip clearance after the test run.

[0069] It can be seen that the structure of the body is stepped, so different numbers of steps can be set, and the height of each step is the same. By observing the number of remaining steps, the minimum blade tip gap can also be quickly obtained.

[0070] Specifically, the structure of the body is designed first. For example, if the body is tested in the shape of steps, the arrangement of the steps, the number of steps, and the height of each step are determined first. Then, the body is coated on the end face of the stator casing facing the rotor blades, and the rotor blades are assembled with the stator casing. When relative rotation occurs after assembly, the tips of the rotating rotor blades will scrape the body. After running for a certain period of time, the number of remaining steps can be observed using a borescope, thus obtaining the tip clearance of the rotor blades.

[0071] Furthermore, the structure of the body can be modified, for example, by dividing the body into multiple measuring sections. These multiple measuring sections are arranged along the length or width of the surface of the stator casing or rotor blade tip, which is beneficial for obtaining the full circumference blade tip clearance and thus better evaluating the rotor-stator eccentricity.

[0072] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation", "connection", "joining", and "fixing" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can also refer to mechanical connections. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0073] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0074] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0075] This application uses specific terms to describe embodiments of the application. Terms such as "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0076] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A contact-type blade tip clearance measuring device, disposed between the stator casing and the rotor blade tip, characterized in that, The measuring device includes: The body includes a connecting end and a measuring end, wherein the connecting end is connected to the stator casing, and the measuring end faces the tip of the rotor blade; wherein, The thickness of the body increases along the direction from the stator casing to the tip of the rotor blade.

2. The contact-type blade tip clearance measuring device according to claim 1, characterized in that, The body has an easy-wear coating.

3. The contact-type blade tip clearance measuring device according to claim 1, characterized in that, The connecting end of the body is coated onto the stator casing.

4. The contact-type blade tip clearance measuring device according to claim 1, characterized in that, The body has a stepped structure along the direction from the stator casing to the tip of the rotor blade.

5. The contact-type blade tip clearance measuring device according to claim 4, characterized in that, Each step of the stepped structure of the body is arranged parallel to the top surface of the rotor blade tip.

6. The contact-type blade tip clearance measuring device according to claim 1, characterized in that, The body has an adjacent first step and a second step along the direction from the stator casing to the rotor blade tip, and the first step and the second step each include multiple steps in the direction away from each other. The first stepped portion and the second stepped portion are symmetrically arranged along their adjacent surfaces.

7. The contact-type blade tip clearance measuring device according to claim 1, characterized in that, The main body is provided with multiple measuring sections along the axial direction of the stator casing or the rotor blade tip.

8. The contact-type blade tip clearance measuring device according to claim 7, characterized in that, Each of the measuring units is arranged in a stepped manner along the direction from the stator casing to the tip of the rotor blade.

9. The contact-type blade tip clearance measuring device according to claim 7, characterized in that, At least one of the measuring parts includes a first stepped part and a second stepped part arranged symmetrically.

10. A contact-type blade tip clearance measurement method, employing the contact-type blade tip clearance measurement device as described in any one of claims 1-9, characterized in that, The measurement method includes: Step 1: Apply the coating to the end face of the stator casing facing the rotor blades; Step 2: When the rotor blades are assembled with the stator casing and they rotate relative to each other, the rotor blades grind the body. Step 3: Use a borescope with the borescope holes opened on the stator casing to observe the thickness of the body and obtain the blade tip clearance.

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