阅读说明：本技术 用于涡轮叶片气膜孔的检测方法 (Detection method for turbine blade air film hole ) 是由 康振亚 郑会龙 杨肖芳 张谭 赵世迁 张晓武 于 2019-10-28 设计创作，主要内容包括：一种用于涡轮叶片气膜孔的检测方法,包括：将树脂涂在涡轮叶片表面及气膜孔内表面；对树脂进行固化,使得固化后的树脂贴合涡轮叶片表面及气膜孔内表面,形成与涡轮叶片结构相同的树脂固化体；将树脂固化体分割成多块,并从涡轮叶片上取下；分别测量分割后的每块树脂固化体的几何形貌；将每块树脂固化体的几何形貌进行拼接,获得涡轮叶片及气膜孔的整体结构模型,根据整体结构模型得到气膜孔相对于涡轮叶片表面的结构、位置及角度。该方法保留了气膜孔结构与叶片的相对位置特征,能够便于全面、系统检测气膜孔的结构形式及精度,且光固化效率高,能够满足现场实际需要。(A method for detecting turbine blade film holes, comprising: coating resin on the surface of the turbine blade and the inner surface of the air film hole; curing the resin to enable the cured resin to be attached to the surface of the turbine blade and the inner surface of the air film hole to form a resin cured body with the same structure as the turbine blade; dividing the resin cured body into a plurality of pieces and taking the pieces off the turbine blades; respectively measuring the geometric shape of each segmented resin solidified body; and splicing the geometric appearances of the resin solidified bodies to obtain an integral structure model of the turbine blade and the air film hole, and obtaining the structure, the position and the angle of the air film hole relative to the surface of the turbine blade according to the integral structure model. The method reserves the relative position characteristics of the structure of the air film hole and the blade, can conveniently and comprehensively detect the structural form and the precision of the air film hole systematically, has high photocuring efficiency, and can meet the actual needs of the site.)

1. A method for detecting turbine blade film holes, comprising:

coating resin on the surface of the turbine blade and the inner surface of the air film hole;

curing the resin to enable the cured resin to be attached to the surface of the turbine blade and the inner surface of the air film hole, so that a resin cured body with the same structure as the turbine blade is formed;

dividing the resin cured body into a plurality of pieces and taking out from the turbine blade;

respectively measuring the geometric shape of each segmented resin solidified body;

and splicing the geometric appearances of the resin solidified bodies to obtain an integral structure model of the turbine blade and the air film hole, and obtaining the structure, the position and the angle of the air film hole relative to the surface of the turbine blade according to the integral structure model.

2. The method of claim 1, wherein the resin is a photosensitive resin.

3. The method according to claim 1, wherein the dividing the resin cured body into a plurality of pieces includes:

and dividing the resin cured body into a plurality of pieces according to the orientation uniformity of the gas film holes.

4. The method of claim 1, wherein the resin is cured by photo-curing.

5. The method according to claim 1, wherein the geometry of each of the divided resin cured bodies is measured by a non-contact measurement method.

6. The method of claim 1, wherein the method further comprises:

and calculating and evaluating errors of the structure, the position and the angle of the film hole relative to the surface of the turbine blade.

7. The method of claim 1, wherein the stitching the geometry of each resin cured body to obtain an overall structural model of the turbine blade and the film hole comprises:

and calculating the precision errors between the integral structure model and the blade profile and between the blade bodies of the real turbine blade.

8. The method of claim 1, further comprising, prior to applying resin to the turbine blade surface and the inner film hole surface:

and cleaning the surface of the turbine blade and the air film hole to remove surface burrs and impurities.

9. The method of claim 1, further comprising:

and cleaning the turbine blade after the resin solidified body is taken off, and removing the resin on the surface of the turbine blade and in the air film hole.

Technical Field

The invention relates to the technical field of power equipment, in particular to a detection method for an air film hole of a turbine blade.

Background

Film cooling has been widely used as an effective method for cooling blades of power equipment. The air film cooling efficiency is influenced by a plurality of factors, wherein the air film hole structure is an important factor, the air film cooling effect can be improved to a great extent by the combined air film hole structure, and the combined air film hole structure has a huge application prospect in reducing the surface temperature of the turbine blade. However, the turbine blade air film holes are small in aperture, large in number, large in depth-diameter ratio, located on the space large-curvature structure of the blade, located on the inner side and irregularly distributed on the hollow curved surface of the blade, and the combined holes are formed by combining straight cylindrical sections and scattered sections.

At present, no universal and mature air film hole detection equipment and method for well completing the detection work of air film holes, particularly combined air film holes, exist in China. In the related technology, a lighting mode combining back lighting and front lighting is adopted, the spatial relative position of a tested structure and a measuring head is changed through linkage between three linear shafts and two rotating shafts, and the measurement of the structure is completed, so that the method is not suitable for carrying out precise detection work of a combined hole air film structure; the research of a geometric precision evaluation method is developed, but the research of an acquisition method of the original coordinate value of the micro-hole is not involved; the process device and the method for carrying out the X-ray detection of the gas edge gas film holes on the turbine blade can meet the detection requirement of the gas film holes which are relatively simply distributed, but are not suitable for a large number of combined holes which are distributed on the blade and have irregular arrangement and large size difference; the detection of the air film hole is completed by adopting a method of projection amplification and image comparison, but the method cannot comprehensively reflect the structural form of the combined air film hole and has low detection efficiency; the CT method is expensive, but the time is long, and the actual requirements of an industrial field cannot be met.

With the increasing demand of power equipment for detecting the air film hole, the detection method suitable for the air film hole, particularly the combined air film hole, is provided urgently.

Disclosure of Invention

Technical problem to be solved

In view of the prior art, the present invention provides a method for detecting an air film hole of a turbine blade, which is used for at least partially solving one of the above technical problems.

(II) technical scheme

The invention provides a detection method for a turbine blade air film hole, which comprises the following steps: coating resin on the surface of the turbine blade and the inner surface of the air film hole; curing the resin so that the cured resin adheres to the turbine blade surface and the inner surface of the film hole to form a cured resin body having the same structure as the turbine blade; dividing the resin cured body into a plurality of pieces and taking the pieces off the turbine blade; respectively measuring the geometric shape of each segmented resin solidified body; and splicing the geometric appearances of the solidified resin bodies to obtain an integral structure model of the turbine blade and the air film hole, and obtaining the structure, the position and the angle of the air film hole relative to the surface of the turbine blade according to the integral structure model.

Optionally, the resin is a photosensitive resin.

Alternatively, the dividing of the resin cured body into a plurality of pieces may include: the cured resin is divided into a plurality of pieces in accordance with the alignment of the gas film holes.

Alternatively, the resin is cured by photo-curing.

Alternatively, the geometry of each of the divided resin cured bodies is measured by a non-contact measurement method.

Optionally, the method further includes: and calculating and evaluating errors of the structure, the position and the angle of the film hole relative to the surface of the turbine blade.

Optionally, the obtaining an overall structural model of the turbine blade and the film hole by splicing the geometric features of each cured resin body includes: and calculating the precision errors between the integral structure model and the blade profile and between the blade bodies of the real turbine blade.

Optionally, the coating of the resin on the turbine blade surface and the inner surface of the film hole further comprises: and cleaning the surface of the turbine blade and the air film hole to remove surface burrs and impurities.

Optionally, the method further includes: and cleaning the turbine blade after the resin solidified body is taken out, and removing the resin on the surface of the turbine blade and in the air film hole.

(III) advantageous effects

The invention provides a detection method for turbine blade air film holes, which has the following beneficial effects:

1. the resin is solidified on the surface of the turbine blade and the inner surface of the air film hole to form a resin solidified block, so that the combined air film hole structure embedded on the inner side of the turbine blade is exposed outside the blade structure, the relative position characteristics of the air film hole structure and the blade are reserved, and the structural form and the precision of the air film hole can be conveniently and comprehensively and systematically detected.

2. The manufacturing and forming of the resin curing block are completed by adopting the photosensitive resin, the resin structure and the blade structure can be attached and formed to the maximum extent, the attaching precision of the resin structure and the blade structure is prevented from being influenced by temperature, the light curing efficiency is high, and the actual requirements on the site can be met.

Drawings

FIG. 1 schematically illustrates a flow chart of a detection method for a turbine blade combined film hole provided by an embodiment of the invention;

FIG. 2 schematically illustrates a block diagram of a turbine blade provided by an embodiment of the present invention.

FIG. 3 schematically illustrates a cross-sectional view of a turbine blade provided by an embodiment of the present invention.

FIG. 4 schematically illustrates a cross-sectional view of a combined gas film hole provided by an embodiment of the invention.

Fig. 5 schematically shows a structural diagram of a turbine blade provided by an embodiment of the invention after being cured by resin filling.

[ reference numerals ]

1-turbine blade

2-Combined air film hole

2 a-combined air film hole straight hole section

2 b-Combined gas film hole diffusion section

3-resin cured body

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings.

According to research, the invention discovers that the curing efficiency and the structural rigidity of the resin are remarkably improved along with the rapid development of the resin material, the characteristics of rapid curing and less heat release of the resin material in a light (such as ultraviolet light) environment are utilized, and the characteristics of stronger structural rigidity of the advanced light-cured resin are utilized to comprehensively reflect the surface of the blade on the outer surface and the structure of the air film hole of the blade, so that a foundation can be provided for the accurate representation of the structural size. On the basis of forming the resin cured block, a non-contact measurement method (non-contact laser scanning, optical image measurement and other methods can be adopted) with small influence on structural deformation is adopted to finish accurate measurement of the structure, and the structural precision of the turbine blade combined film hole can be accurately evaluated.

FIG. 1 schematically illustrates a flow chart of a detection method for a turbine blade combined film hole, according to an embodiment of the invention. As shown in fig. 1, the method may include, for example, operations S101 to S107.

In operation S101, the turbine blade surface and the film hole are cleaned to remove surface burrs and impurities.

A plurality of impurities exist on the surface of the turbine blade after being machined, burrs are easily left near the orifice after the air film hole is machined, and in order to guarantee the accuracy of combined hole structure measurement, the structure needs to be cleaned, so that the resin solidified body can completely reflect the specific characteristics of the air film structure.

FIG. 2 schematically illustrates a block diagram of a turbine blade provided by an embodiment of the present invention, FIG. 3 schematically illustrates a cross-sectional view of a turbine blade provided by an embodiment of the present invention, and FIG. 4 schematically illustrates a cross-sectional view of a combined film hole provided by an embodiment of the present invention. The turbine blade with the uniformly arranged film holes is detected by the embodiment of the invention, the structure of which is shown in fig. 2-4, and the combined film holes are positioned on the back of the turbine blade and are uniformly arranged. The combined air film holes 2 are distributed on the surface of the turbine blade 1, and the combined air film holes 2 comprise a combined air film hole straight hole section 2a and a combined air film hole diffusion section 2b, wherein the combined air film hole straight hole section 2a can be a straight hole and a taper hole, and the combined air film hole diffusion section 2b can be a dustpan-shaped open through hole or a cat ear open through hole.

The detection method described in this embodiment is not limited to the turbine blade shown in fig. 2, 3 and 4, the arrangement of the film holes of the turbine blade actually measured may be uneven and discontinuous, and the position of the combined film holes may be the position of the leading edge, the trailing edge, the pressure surface or the suction surface of the blade.

In operation S102, resin is coated on the turbine blade surface and the inner surface of the film hole.

Spraying resin on the surface of the turbine blade and filling the air film holes, wherein the resin is required to be coated on the surface of the turbine blade during spraying, the resin is not required to be strictly and uniformly distributed, the resin is properly immersed and filled in the air film holes, as shown in fig. 5, the resin is paved on the surface of the turbine blade 1, and part of the resin is filled in the combined air film hole straight hole section 2a and the combined air film hole diffusion section 2 b. The resin may be, for example, a photosensitive resin. The light resistance is sensitive to light and insensitive to temperature, so that the influence of the temperature on the fitting precision between the resin and the surfaces of the turbine blade and the inner surface of the air film hole can be avoided.

In operation S103, the resin is cured so that the cured resin adheres to the turbine blade surface and the inner surface of the film hole, thereby forming a cured resin body having the same structure as the turbine blade.

The curing means may be, for example, light curing. When the composite film hole is cured, the phenomenon that the metal part of the turbine blade expands with heat and contracts with cold due to local overheating of the turbine blade is avoided, and the relative position relation of the composite film hole relative to the blade profile and the blade body can be fully reflected by the resin cured body. As shown in fig. 5, the curing is completed by light irradiation, and since the heat generation amount is small, the structure of the resin cured body 3 formed after curing reflects the structural forms of the combined gas film hole straight hole section 2a and the combined gas film hole diffusion section 2b, and reflects the distribution positions of the combined gas film hole straight hole section 2a and the combined gas film hole diffusion section 2b relative to the blade profile, and the actual blade morphology of the turbine blade 1 and the structural forms of the combined gas film hole straight hole section 2a and the combined gas film hole diffusion section 2b can be indirectly measured by measuring the geometric morphology of the resin cured body 3 close to the turbine blade 1, so that accurate measurement and model quality evaluation are finally realized.

In operation S104, the resin cured body is divided into a plurality of pieces and removed from the turbine blade.

The design form of the air film holes needs to be fully considered during cutting, and the cutting blocks are divided according to the principle of the direction consistency of the air film holes. For example, the block dividing method can be determined according to the inclination angle of the film hole relative to the blade surface during dividing, so that the film hole position does not move and interfere when the block is detached and taken out, and the divided resin solidified body is convenient to take out. Here, the resin cured body may be divided into, for example, not less than 2 pieces.

In operation S105, the geometry of each of the divided resin cured bodies is measured, respectively.

And a precision appearance structure measuring platform is adopted to carry out geometric precision measurement on the segmented resin solidified body according to blocks, the adopted geometric precision measurement method is a non-contact measurement method so as to avoid the influence of contact measurement on the deformation of the structure, and the non-contact measurement mode can be laser scanning measurement or other structure appearance precision measurement modes such as optical image measurement and the like.

In operation S106, the geometric features of each resin cured body are spliced to obtain an overall structure model of the turbine blade and the film hole, and a structure, a position, and an angle of the film hole with respect to the surface of the turbine blade are obtained according to the overall structure model.

Splicing and evaluating the obtained turbine blade model measuring block structure (geometric morphology) in a computer, and finally obtaining the whole structure of the turbine blade and the combined air film hole structure. After the turbine blade model block measurement results are spliced in a computer, the blade body models of the inner surface of the spliced model and the outer surface of the original blade can be evaluated, namely, the precision errors between the blade profile and the blade body of the whole structure model and the real turbine blade are calculated, and the structure, the position and the angle of the combined air film hole relative to the outer surface of the blade of the spliced model can be obtained based on the spliced model, so that the calculation and evaluation of the air film hole structure errors are completed.

In operation S107, the turbine blade after the resin cured body is removed is cleaned to remove the resin on the surface of the turbine blade and in the air film hole.

And (3) immersing the turbine blade with the resin solidified body removed into a cleaning solution, taking out the turbine blade and drying the turbine blade after the resin is fully soaked and dissolved, wherein the liquid for cleaning the surface of the turbine blade and the air film hole comprises water, alcohol or other organic solvents.

In summary, the present invention provides a method for detecting a gas film hole of a turbine blade, in which a resin is cured on the surface of the turbine blade and the inner surface of the gas film hole to form a resin cured block, so that a combined gas film hole structure embedded inside the turbine blade is exposed outside the blade structure, and the relative position characteristics of the gas film hole structure and the blade are retained, thereby facilitating comprehensive and systematic detection of the structural form and accuracy of the gas film hole. And moreover, the manufacturing and forming of the resin curing block are completed by adopting the photosensitive resin, the resin structure and the blade structure can be attached and formed to the maximum extent, the attachment precision of the resin structure and the blade structure is prevented from being influenced by temperature, the light curing efficiency is high, and the actual requirements on the site can be met.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.