Turbine blade surface flow field visualization method based on active deposition tracing

Abstract

The invention relates to a turbine blade surface flow field visualization method based on active deposition tracing. The turbine blade surface flow field visualization method comprises the following steps that S1, a turbine blade is scanned and installed; s2, setting tracer particles: selecting mullite powder as the tracer particles; s3, active deposition: the gas turbine is started to operate, mullite is injected into a gas inlet of a combustion chamber and deposited on the surface of a turbine blade, and an aluminum oxide deposition layer is formed; s4, dismounting and scanning the turbine blade; s5, comparing and analyzing data: performing three-dimensional comparing and analyzing on the first point cloud data and the second point cloud data, and identifying the aluminum oxide deposition layer on the surface of the turbine blade; and S6, blade surface flow field visualization: thickness distribution of the aluminum oxide deposition layer in each area of the turbine blade surface is quantified, a deposition thickness cloud picture is generated, and the deposition thickness cloud picture is a visual image of the turbine blade surface flow field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of turbine blade, and particularly relates to a turbine blade surface flow field visualization method based on active deposition tracing. BACKGROUND

[0002] The turbine blade is a core component of a gas turbine power system, and the design level of the turbine blade directly determines the aerodynamic performance and operation reliability of the whole machine. The traditional turbine blade design mainly focuses on two dimensions: one is the three-dimensional flow field structure of the turbine blade surface, including the flow path, wall adhesion and diffusion behavior of the main flow gas and the film cooling gas flow, and the characteristics directly determine the aerodynamic efficiency and cooling reliability of the turbine blade; the other is the optimization of the film cooling system. Under ideal working conditions, the cooling gas should be closely attached to the turbine blade surface after being injected from the film hole, forming a continuous and stable low-temperature protection layer, so as to effectively isolate the high-temperature gas and ensure the safe operation of the turbine blade in the high-temperature gas.

[0003] However, whether it is the three-dimensional flow field structure of the turbine blade surface or the optimization of the film cooling system, the turbine blade surface flow field information under the real working condition is needed, and the traditional method for obtaining the turbine blade surface flow field information is mostly limited to theoretical calculation, numerical simulation and particle image velocimetry technology based on optical principles, which is difficult to obtain accurate turbine blade surface flow field information in the actual operation working condition of the gas turbine full of uncertainty and random factors, and seriously restricts the design optimization of the turbine blade. SUMMARY

[0004] In view of the defects of the prior art described above, the technical problem to be solved by the present application is to provide a turbine blade surface flow field visualization method based on active deposition tracing, which can convert the invisible airflow flow phenomenon into quantifiable deposition distribution, and provide an effective reference for the design and verification of the turbine blade.

[0005] To achieve the above-mentioned purpose, the present application provides a turbine blade surface flow field visualization method based on active deposition tracing, which comprises the following steps:

[0006] S1, scanning and installing the turbine blade: comprehensively scanning the turbine blade to obtain the first point cloud data of the turbine blade, and installing the turbine blade on the gas turbine;

[0007] S2, setting the tracer particles: selecting mullite powder as the tracer particles, and the particle size of the mullite is less than 100 microns;

[0008] S3, active deposition: starting the gas turbine, after the gas turbine runs to the normal working state, injecting the mullite into the inlet of the combustion chamber, so that it can mix with the airflow and deposit on the surface of the turbine blade to form an aluminum oxide deposition layer.

[0009] S4, stop scanning: the gas turbine stops running, and the turbine blade is removed from the gas turbine, and the turbine blade is scanned again to obtain second point cloud data of the turbine blade;

[0010] S5, comparative analysis data: the first point cloud data and the second point cloud data are compared and analyzed in three dimensions to identify the aluminum oxide deposition layer on the surface of the turbine blade;

[0011] S6, blade surface flow field visualization: based on the deposition distribution of the aluminum oxide deposition layer on the surface of the turbine blade, the thickness distribution of the aluminum oxide deposition layer in each region on the surface of the turbine blade is accurately quantified, and a deposition thickness cloud map is generated, which is a visual image of the turbine blade surface flow field.

[0012] Further, in step S1, a blue light scanner is used to scan the turbine blade in three dimensions, and the ambient light is stable during the scanning process to avoid interference.

[0013] Further, in step S2, the particle size of the mullite is set to 10-50 microns.

[0014] Further, in step S2, the mullite powder is placed in the powder feeder, and the powder feeder is installed at the inlet of the combustion chamber of the gas turbine.

[0015] Further, in step S3, the powder feeder includes a spraying mechanism for spraying mullite, and when the mullite is injected into the inlet of the combustion chamber, the mullite in the powder feeder is uniformly injected into the inlet of the combustion chamber through the spraying mechanism, so that it can be mixed into the gas flow in the inlet, and react, decompose and deposit on the surface of the turbine blade to form an aluminum oxide deposition layer.

[0016] Further, in step S3, the amount of mullite injected is calculated according to the power of the gas turbine, and the mullite is injected into the inlet of the combustion chamber, and the calculation formula is as follows:

[0017] V=k×P (1)

[0018] In the formula, V is the amount of mullite injected; k is the dosage coefficient, which is 0.2-0.5; P is the power of the gas turbine.

[0019] Further, in step S4, a blue light scanner is used to scan the turbine blade again in three dimensions, and the ambient light is stable during the scanning process to avoid interference.

[0020] As described above, the turbine blade surface flow field visualization method based on active deposition tracing has the following beneficial effects:

[0021] 1. The present application injects tracer particles, i.e. mullite powder, into the combustion chamber inlet, and promotes the decomposition of the mullite powder to produce alumina, which quickly deposits in the low-flow area of the turbine blade surface, and reversely calculates the flow field condition of the turbine blade surface according to the thickness distribution, converts the invisible flow field information into visible and quantifiable deposition thickness cloud map, converts the abstract into the concrete, realizes the visual display of the flow field structure, intuitively reflects the turbine blade surface flow field information under real working conditions, thereby providing a reference for turbine blade design, and has important engineering application value.

[0022] 2. The alumina deposition layer formed by the decomposition and deposition of mullite powder will not damage the turbine blade surface coating, and can also provide heat insulation, which is conducive to the long-term service of the turbine blade.

[0023] 3. The turbine blade surface flow field visualization method of the present application can be realized based on the modification of the existing test bench, or directly tested on a gas turbine, without the need for special construction of complex devices, and has low cost, short cycle, strong applicability, good engineering application and industrialization prospects. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The flow chart of the turbine blade surface flow field visualization method of the present application. DETAILED DESCRIPTION

[0025] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings. These embodiments are only used to illustrate the present application, and are not limiting to the present application.

[0026] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication between the two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] Further, in the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0029] Referring to Figure 1 The present application provides a turbine blade surface flow field visualization method based on active deposition tracing, the turbine blade surface flow field visualization method comprising the following steps:

[0030] S1, scanning and installing the turbine blade: comprehensively scanning the turbine blade to obtain first point cloud data of the turbine blade, and installing the turbine blade on the gas turbine, preferably, ensuring that the cooling air flow passage of the turbine blade is unobstructed before installation;

[0031] S2, setting the tracer particles: selecting mullite powder as the tracer particles, specifically, the chemical formula of mullite is 3Al2O3•2SiO2, which is a high-quality refractory raw material, and can decompose to form aluminum oxide and silicon hydroxide under the influence of water vapor, wherein the aluminum oxide can be deposited on the surface of the turbine blade, and the particle size of the mullite is less than 100 microns;

[0032] S3, active deposition: starting the gas turbine, after the gas turbine runs to the normal working state, injecting the mullite into the inlet of the combustion chamber so that it can mix with the airflow and be deposited on the surface of the turbine blade to form an aluminum oxide deposition layer, preferably, monitoring various operating parameters of the gas turbine during active deposition to ensure stable operation of the gas turbine;

[0033] S4, shutdown scanning: stopping the operation of the gas turbine, preferably, gradually reducing the load of the gas turbine and stopping according to safety regulations after the set operating time ends, ensuring that all systems of the gas turbine are safely closed, and the turbine blade is removed from the gas turbine, and the turbine blade is scanned again to obtain second point cloud data of the turbine blade;

[0034] S5, comparative analysis of data: comparing and analyzing the first point cloud data and the second point cloud data in three dimensions, preferably, importing the first point cloud data and the second point cloud data into the Geomagic Wrap 3D scanning analysis software, converting the first point cloud data and the second point cloud data into reverse engineering 3D models, and processing and analyzing them to identify the aluminum oxide deposition layer on the surface of the turbine blade;

[0035] S6, the blade surface flow field visualization: based on the deposition distribution of the turbine blade surface alumina deposition layer, the thickness distribution of the alumina deposition layer in each region of the turbine blade surface is accurately quantified, and a deposition thickness cloud chart is generated, and the deposition thickness cloud chart is the visualization image of the turbine blade surface flow field, specifically, in the deposition thickness cloud chart, the region with larger thickness is the low speed region or vortex region of the flow field, and the region with thinner deposition thickness or no deposition is the high speed region of the flow field.

[0036] The basic working principle of the turbine blade surface flow field visualization method based on active deposition tracing provided by the application is as follows: the application uses mullite as a tracing particle, utilizes the selective deposition characteristics of mullite, combines three-dimensional scanning and data comparison, and reversely realizes the visualization of the turbine blade surface flow field, specifically, through step S1, the first point cloud data of the turbine blade can be scanned and acquired, and the turbine blade is installed on the gas turbine; through step S2, mullite powder with a suitable particle size can be selected; through step S3, mullite can be actively injected into the gas turbine combustion chamber inlet, so that mullite is actively decomposed to form alumina and silicon hydroxide under the influence of water vapor, and then alumina can be actively and rapidly deposited on the turbine blade surface; through step S4, the turbine blade can be removed from the gas turbine, and the second point cloud data of the turbine blade can be scanned and acquired; through step S5, three-dimensional comparison and analysis are performed on the first point cloud data and the second point cloud data of the turbine blade before and after active deposition, and then the alumina deposition layer on the turbine blade surface is identified; through step S6, the thickness distribution of the alumina deposition layer in each region of the turbine blade surface can be accurately quantified, and a deposition thickness cloud chart can be generated, and then the flow field state of the turbine blade surface can be directly reflected by the thickness difference, and the turbine blade surface flow field information under the real working condition can be obtained, thereby providing an effective reference for the design and verification of the turbine blade.

[0037] Referring to Figure 1 , the application will be further described below with reference to a specific embodiment:

[0038] In this embodiment, referring to Figure 1 , as a preferred design, in step S1, a blue light scanner is used to perform comprehensive three-dimensional scanning on the turbine blade, and it is ensured that the ambient light is stable during the scanning process to avoid interference.

[0039] In this embodiment, referring to Figure 1 , as a preferred design, in step S2, the particle size of mullite is set to 10-50 microns.

[0040] In this embodiment, referring to Figure 1As a preferred design, in step S2, the mullite powder is placed in the powder feeder, and the powder feeder is installed at the combustion chamber air inlet of the gas turbine, preferably, the powder feeder is multiple, and the multiple powder feeders are evenly arranged along the circumference of the combustion chamber air inlet, so that the mullite can be uniformly and stably injected into the main flow gas of the gas turbine.

[0041] In the embodiment, referring to Figure 1 As a preferred design, in step S3, the powder feeder comprises a spraying mechanism for spraying the mullite, and when the mullite is injected into the combustion chamber air inlet, the mullite in the powder feeder is uniformly injected into the combustion chamber air inlet through the spraying mechanism, so that the mullite can be mixed into the airflow of the air inlet and react, decompose and deposit on the surface of the turbine blade to form an aluminum oxide deposition layer.

[0042] In the embodiment, referring to Figure 1 As a preferred design, in step S3, the injection amount of the mullite is calculated according to the power of the gas turbine, and the mullite is injected into the combustion chamber air inlet, and the calculation formula is as follows:

[0043] V=k×P (1)

[0044] In the formula, V is the injection amount of the mullite, k is the dosage coefficient, and is 0.2-0.5, and P is the power of the gas turbine. Specifically, in the embodiment, the power of the gas turbine is 300MW, and the injection amount of the mullite ranges from 60kg to 130kg, preferably 90kg, and the total injection time of the mullite is greater than 150h, so that when the mullite is mixed into the airflow of the air inlet, the mullite can fully react, decompose and deposit on the surface of the turbine blade to form an obvious aluminum oxide deposition layer.

[0045] In the embodiment, referring to Figure 1 As a preferred design, in step S4, the blue light scanner is used to perform a comprehensive three-dimensional scanning on the turbine blade again, and the ambient light is stable during the scanning process to avoid interference.

[0046] As described above, the turbine blade surface flow field visualization method based on active deposition tracing according to the present application has the following beneficial effects:

[0047] 1. The present application actively injects tracer particles, i.e. mullite powder, into the combustion chamber air inlet, and promotes the decomposition of the mullite to produce aluminum oxide, which quickly deposits in the area with low local airflow velocity on the surface of the turbine blade, and the airflow field condition on the surface of the turbine blade is inversely deduced according to the thickness distribution, so that the invisible flow field information is converted into a visible and quantifiable deposition thickness cloud picture, the abstract is converted into the concrete, the visualization display of the flow field structure is realized, the turbine blade surface flow field information under the real working condition is intuitively reflected, and the turbine blade design is provided with reference, which has important engineering application value.

[0048] 2. The alumina deposit layer formed by the decomposition and deposition of mullite powder will not damage the surface coating of the turbine blade, and can also provide heat insulation, which is beneficial to the long-term service of the turbine blade.

[0049] 3. The turbine blade surface flow field visualization method of the present invention can be implemented by modifying existing test rigs or directly tested on gas turbines. It does not require the construction of complex equipment, has low cost, short cycle, and strong applicability, and has good engineering application and industrialization prospects.

[0050] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0051] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for visualizing the flow field on the surface of a turbine blade based on active deposition tracing, characterized in that: The method for visualizing the flow field on the surface of a turbine blade includes the following steps: S1. Scan and install turbine blades: Perform a full three-dimensional scan of the turbine blades to obtain the first point cloud data of the turbine blades, and install the turbine blades onto the gas turbine. S2. Set tracer particles: Select mullite powder as tracer particles, wherein the particle size of the mullite is less than 100 micrometers; S3. Active deposition: After the gas turbine is started and running, mullite is injected into the combustion chamber inlet after the gas turbine has reached normal operating conditions, so that it can be mixed with the airflow and deposited on the surface of the turbine blades to form an alumina deposit layer. S4. Shutdown Scan: The gas turbine is stopped and the turbine blades are removed from the gas turbine. The turbine blades are then subjected to a full three-dimensional scan to obtain the second point cloud data of the turbine blades. S5. Comparative Analysis of Data: Perform a three-dimensional comparative analysis of the first point cloud data and the second point cloud data to identify the alumina deposition layer on the surface of the turbine blade. S6. Visualization of flow field on turbine blade surface: Based on the deposition distribution of alumina deposits on the turbine blade surface, the thickness distribution of the alumina deposits in each region of the turbine blade surface is accurately quantified, and a deposition thickness cloud map is generated. The deposition thickness cloud map is a visualization image of the flow field on the turbine blade surface.

2. The method for visualizing the flow field on the surface of a turbine blade based on active deposition tracing according to claim 1, characterized in that: In step S1, a blue light scanner is used to perform a comprehensive three-dimensional scan of the turbine blade, and the ambient light is kept stable during the scanning process to avoid interference.

3. The method for visualizing the flow field on the surface of a turbine blade based on active deposition tracing according to claim 2, characterized in that: In step S2, the particle size of the mullite is set to 10-50 micrometers.

4. The method for visualizing the flow field on the surface of a turbine blade based on active deposition tracing according to claim 3, characterized in that: In step S2, mullite powder is placed in a powder dispenser and the powder dispenser is installed at the combustion chamber inlet of the gas turbine.

5. The method for visualizing the flow field on the surface of a turbine blade based on active deposition tracing according to claim 4, characterized in that: In step S3, the powder dispenser includes a spraying mechanism for spraying mullite. When mullite is injected into the combustion chamber air inlet, the spraying mechanism evenly injects the mullite in the powder dispenser into the combustion chamber air inlet, so that it can mix with the airflow in the air inlet and react, decompose, and deposit on the surface of the turbine blade to form an alumina deposit layer.

6. The method for visualizing the flow field on the surface of a turbine blade based on active deposition tracing according to claim 5, characterized in that: In step S3, the amount of mullite to be injected is calculated based on the power of the gas turbine, and the mullite is injected into the combustion chamber inlet. The calculation formula is as follows: V=k×P (1) In the formula, V is the amount of mullite injected; k is the dosage coefficient, which is taken as 0.2-0.5; and P is the power of the gas turbine.

7. The method for visualizing the flow field on the surface of a turbine blade based on active deposition tracing according to claim 6, characterized in that: In step S4, a blue light scanner is used to perform a full three-dimensional scan of the turbine blade again, and the ambient light is kept stable during the scanning process to avoid interference.

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