A pre-deformation design method for moving blades of axial compressor of marine gas turbine

Abstract

The purpose of the present invention is to provide a pre-deformation design method for moving blades of an axial flow compressor of a ship gas turbine. The present invention comprehensively considers the performance requirements of the ship gas turbine for different compressor operating conditions and the influence of blade deformation on the compressor performance, takes the blade inlet and outlet geometric angles as control variables and performs pre-deformation design through specific formulas associated with the operating conditions to obtain the final processing blade profile of the compressor moving blades. The pre-deformation design method for moving blades of an axial flow compressor of a ship gas turbine proposed in the present invention realizes the parameterization and customization of the pre-deformation design through key control variables, seamlessly connects the pre-deformation design with the traditional compressor aerodynamic design process, improves the refinement level of the aerodynamic design of the ship gas turbine compressor, and shortens the design cycle. At the same time, the present invention is not only limited to the axial flow compressor of a ship gas turbine, but is also applicable to the aerodynamic design process of various industrial axial flow compressors and axial flow compressors of aircraft engines.

Description

Technical Field

[0001] The present invention relates to a gas turbine compressor, in particular to a design method for compressor blades. Background Art

[0002] As one of the most important core components of a ship's gas turbine, the performance of the compressor directly determines the overall technical indicators of the ship's gas turbine. With the continuous development of the performance of ship gas turbines, the load level of compressor components is also increasing rapidly. In order to adapt to higher load capacity and blade tip tangential speed, the compressor moving blades often adopt a more complex three-dimensional spatial configuration and a thinner blade thickness, which reduces their relative rigidity. Under the combined action of aerodynamic loads and centrifugal loads, they are prone to large deformations. The blade shape is a key factor in determining the performance of the compressor. Ensuring that the blade shape is as close to the aerodynamic design state as possible during the operation of the compressor is an important link and guarantee for achieving the compressor design indicators.

[0003] The deformation of the blades under actual working conditions will have a direct impact on the blade modeling parameters, which will lead to deviations between the gas flow in the compressor blade channel and the design expectations. Especially for high-load and transonic stages, the deformation of the moving blades will cause the shock wave position to move, thereby deviating from its optimal design point, affecting the compressor performance and efficiency, and even causing problems such as aeroelastic stability. Only when the blade profile of the actual working state of the blade matches the aerodynamic design blade profile during the operation of the compressor can the optimal aerodynamic performance of the blade be obtained. For this reason, in the compressor design process, the impact of blade deformation on aerodynamic performance must be fully considered, and the reverse design process from the aerodynamic design blade profile to the processing blade profile data, that is, the pre-deformation design of the blade, must be carried out.

[0004] Due to the operating characteristics of ship gas turbines, the design efficiency of the compressor and the surge margin under low operating conditions are extremely high. The deformation of the compressor moving blades under different operating conditions is different, which brings great challenges to the pre-deformation design. It is of great significance to develop a compressor moving blade pre-deformation design method suitable for engineering design applications and capable of fully considering the influence of variable operating conditions of ship gas turbines. Summary of the invention

[0005] The object of the present invention is to provide a method for pre-deforming moving blades of an axial flow compressor of a ship gas turbine, which can solve the problem of compressor performance attenuation caused by moving blade deformation during actual operation of the ship gas turbine compressor.

[0006] The object of the present invention is achieved in that:

[0007] The present invention provides a method for designing the pre-deformation of moving blades of an axial flow compressor of a ship gas turbine, which is characterized by:

[0008] (1) Conduct static analysis under the centrifugal force and aerodynamic force of typical working conditions. For the moving blades that need to be pre-deformed in the aerodynamic design of the axial compressor, select the typical working condition as the pre-deformation design condition, extract the centrifugal force and aerodynamic force on the moving blade under the working condition, conduct static analysis of the moving blade under the typical working condition, and obtain the hot working blade of the moving blade when the compressor is running under the typical working condition;

[0009] (2) Calculation of inlet and outlet geometric angle deviation: Extract the inlet geometric angle β1′ of each section of the hot working blade c , calculation and aerodynamic design of the blade inlet geometry angle β 1c Deviation Δ 1c , that is, Δ 1c =β′ 1c -β 1c ; Extract the outlet geometric angle β′ of each section of the hot working blade 2c , calculation and aerodynamic design of the blade outlet geometry angle β 2c Deviation Δ 2c , that is, Δ 2c =β′ 2c -β 2c ; For n typical working conditions, the geometric angle deviation of the inlet and outlet under the first typical working condition is Δ 1c,1 , Δ 2c,1 , and so on, the geometric angle deviation of the inlet and outlet under the nth typical working condition is Δ 1c,n , Δ 2c,n ;

[0010] (3) Correcting the blade modeling parameters: Based on the calculation results of the inlet and outlet geometric angle deviations, the inlet and outlet geometric angle parameters of the aerodynamic design moving blades are corrected and the blade modeling is performed again to obtain the corresponding transition state blades;

[0011] (4) Perform three-dimensional CFD calculation and analysis of the compressor under typical working conditions, replace the corresponding moving blades in the aerodynamic design of the axial compressor with transitional blades, perform three-dimensional CFD calculation of the compressor as a whole under typical working conditions, return the calculation results to step (1) for static analysis, obtain the hot working blades of the transitional blades when the compressor is running under typical working conditions, and perform inlet and outlet geometric angle deviation calculation according to step (2);

[0012] (5) Determine whether the pre-deformation design convergence condition is met, and judge the geometric angle deviation of the inlet and outlet of each shape section of the blade calculated in the previous step, and determine the Δ 1c , Δ 2c Whether the pre-deformation design convergence condition is met, if it is met, the transition state blade can be used as the expected processing blade for the next step; if not, Δ 1c , Δ 2cReturn to step (3) and iterate until Δ 1c , Δ 2c Until the convergence condition is met;

[0013] (6) Performing static analysis at a specific speed of the compressor, selecting a commonly used operating speed of the compressor as the specific speed, performing static analysis at each specific speed on the expected processing blade, and obtaining the hot working blade corresponding to the expected processing blade at each specific speed;

[0014] (7) Perform three-dimensional CFD calculation and analysis at a specific speed of the compressor, replace the corresponding blades in the aerodynamic design of the axial compressor with the hot working blades corresponding to the expected processed blades at each specific speed, and perform three-dimensional CFD calculation and analysis at each specific speed. Through the three-dimensional CFD calculation, the performance and internal flow field conditions of the compressor at each specific speed are obtained to determine whether the performance requirements are met. If the performance requirements are met, the blade profile data of each cross-section of the expected processed blade obtained in step (5) is used as the final processed blade profile data; if the performance requirements are not met, the convergence condition in step (5) is further reduced, and the process returns to step (1) to iterate according to the new convergence condition. Through repeated iterations, the final processed blade profile data of the axial compressor moving blade that finally meets the performance requirements is obtained.

[0015] The present invention may also include:

[0016] 1. The moving blades that need to be pre-deformed in the aerodynamic design of the axial compressor described in step (1) are moving blades with large deformation and high incoming flow Mach number under working conditions.

[0017] 2. The typical operating condition selected as the pre-deformation design operating condition in step (1) is the compressor design point and the near-surge point at 70% of the design speed as the typical operating condition.

[0018] 3. Based on the calculation result of the inlet and outlet geometric angle deviation described in step (3), the inlet and outlet geometric angle parameters of the moving blades of the aerodynamic design scheme are corrected in the following manner:

[0019] The corrected inlet geometric angle of each section of the moving blade is calculated according to the following formula:

[0020]

[0021] The outlet geometry angle is calculated as follows:

[0022]

[0023] Where a and b are pre-deformation scaling coefficients, and a=1 and b=1 are initially taken.

[0024] 4. The convergence condition of the pre-deformation design described in step (5) is as follows: for n typical working conditions, the Δ of all the profiled sections of the moving blades under all working conditions is 1c , Δ 2c All are no greater than 0.2°.

[0025] 5. In step (6), several commonly used operating speeds of the compressor are selected as the specific speeds. For a ship gas turbine axial flow compressor, 4 to 5 characteristic operating speeds are selected as the specific speeds within the range of 70% to 105% of the design speed.

[0026] The advantages of the present invention are:

[0027] 1. The pre-deformation design method for the moving blades of the axial flow compressor of a ship gas turbine proposed in the present invention comprehensively considers the performance requirements of the ship gas turbine on the compressor under different operating conditions and the influence of blade deformation, effectively solves the problem of performance attenuation of the ship gas turbine compressor caused by the deformation of the moving blades under different operating conditions, and effectively improves the performance of the ship gas turbine compressor in the full range of operating conditions.

[0028] 2. The blade inlet and outlet geometric angles are used as the control variables of the pre-deformation design. They can be directly adjusted in the blade modeling design program, making the pre-deformation design seamlessly connected with the traditional compressor aerodynamic design process. This realizes the parameterization and customization of the pre-deformation design, effectively improving the refinement level of the aerodynamic design of the ship gas turbine compressor and shortening the design cycle.

[0029] 3. It is not limited to the axial flow compressor of ship gas turbine, but also applicable to the aerodynamic design process of various industrial axial flow compressors and aircraft engine axial flow compressors. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0031] The present invention is described in more detail below with reference to the accompanying drawings:

[0032] Combination Figure 1 The specific implementation method of the pre-deformation design method of the axial flow compressor blade of a ship gas turbine of the present invention is realized by the following steps:

[0033] Step 1: Static analysis under centrifugal force and aerodynamic force of typical working conditions. For the moving blades that need to be pre-deformed in the aerodynamic design of the axial compressor, select the typical working condition as the pre-deformation design condition, extract the centrifugal force and aerodynamic force of the moving blade under this condition, and perform static analysis of the moving blade under the typical working condition to obtain the hot working blade of the moving blade when the compressor is operating under the typical working condition.

[0034] Among them, the moving blades that need to be pre-deformed are generally the moving blades with large deformation and high incoming flow Mach number under working conditions, such as transonic moving blades; typical working conditions usually select the compressor design point and the near surge point at 70% of the design speed.

[0035] Step 2: Calculation of inlet and outlet geometric angle deviation. Extract the inlet geometric angle β′ of each section of the hot working blade 1c , calculation and aerodynamic design of the blade inlet geometry angle β 1c Deviation Δ 1c , that is, Δ 1c =β′ 1c -β 1c ; Extract the outlet geometric angle β′ of each section of the hot working blade 2c , calculation and aerodynamic design of the blade outlet geometry angle β 2c Deviation Δ 2c , that is, Δ 2c =β′ 2c -β 2c ; For n typical working conditions, the geometric angle deviation of the inlet and outlet under the first typical working condition is Δ 1c,1 , Δ 2c,1 , and so on, the geometric angle deviation of the inlet and outlet under the nth typical working condition is Δ 1c,n , Δ 2c,n .

[0036] Step 3: Correction of blade modeling parameters. Based on the calculation results of the inlet and outlet geometric angle deviation, the inlet and outlet geometric angle parameters of the aerodynamic design moving blade are corrected and the blade modeling is performed again to obtain the corresponding transitional blade. The correction method is as follows:

[0037] Calculation of the corrected inlet geometric angles of each section of the moving blade:

[0038]

[0039] Calculation of outlet geometry:

[0040]

[0041] Where a and b are the pre-deformation scaling coefficients, and generally a=1 and b=1 are taken as the initial value. If the pre-deformation design converges slowly, the values ​​of a and b can be appropriately fine-tuned.

[0042] Step 4: 3D CFD calculation and analysis of the compressor under typical working conditions. Replace the corresponding moving blades in the aerodynamic design of the axial compressor with transitional blades, perform 3D CFD calculation of the compressor as a whole under typical working conditions, return the calculation results to step 1 for static analysis, obtain the hot working blades of the transitional blades when the compressor is running under typical working conditions, and calculate the inlet and outlet geometric angle deviation according to step 2;

[0043] Step 5: Determine whether the pre-deformation design convergence condition is met. Determine the geometric angle deviation of the inlet and outlet of each blade section calculated in the previous step, and determine the Δ 1c , Δ 2c Whether the pre-deformation design convergence condition is met. If so, the transitional blade can be used as the expected processing blade for the next step; if not, Δ 1c , Δ 2c Return to step 3 and iterate until Δ 1c , Δ 2c until the convergence condition is met.

[0044] The convergence condition of pre-deformation design is as follows: for n typical working conditions, the Δ of all the profiled sections of the moving blades under all working conditions is 1c , Δ 2c All are no greater than 0.2°.

[0045] Step 6: Static analysis of the compressor at a specific speed. Select several commonly used operating speeds of the compressor as the specific speeds. For the axial flow compressor of a ship gas turbine, 4 to 5 characteristic operating speeds are usually selected as the specific speeds within the range of 70% to 105% of the design speed. Perform static analysis of the expected processing blades at each specific speed to obtain the hot working blades corresponding to the expected processing blades at each specific speed.

[0046] Step seven: Three-dimensional CFD calculation and analysis at specific speeds of the compressor. Replace the corresponding blades in the aerodynamic design of the axial compressor with the hot working blades corresponding to the expected processed blades at each specific speed, and perform three-dimensional CFD calculation and analysis at each specific speed. Through three-dimensional CFD calculation, the performance and internal flow field conditions of the compressor at each specific speed are obtained to determine whether the performance requirements are met. If the performance requirements are met, the blade profile data of each cross-section of the expected processed blade obtained in step five can be used as the final processed blade profile data; if the performance requirements are not met, the convergence conditions in step five are further reduced, and return to step one to iterate according to the new convergence conditions. Through repeated iterations of the above steps, the final processed blade profile data of the axial compressor moving blades that ultimately meet the performance requirements are obtained.

[0047] The method for pre-deformation design of moving blades of a ship gas turbine axial flow compressor proposed in the present invention is universal and is not limited to ship gas turbine axial flow compressors, but is also applicable to the aerodynamic design process of various industrial axial flow compressors and aircraft engine axial flow compressors.

Claims

1. A method for designing the pre-deformation of moving blades of an axial flow compressor of a ship gas turbine, characterized in that: (1) Conduct static analysis under the centrifugal force and aerodynamic force of typical working conditions. For the moving blades that need to be pre-deformed in the aerodynamic design of the axial compressor, select the typical working condition as the pre-deformation design condition, extract the centrifugal force and aerodynamic force on the moving blade under the working condition, conduct static analysis of the moving blade under the typical working condition, and obtain the hot working blade of the moving blade when the compressor is running under the typical working condition; (2) Calculation of inlet and outlet geometric angle deviation: Extract the inlet geometric angle β′ of each section of the hot working blade 1c , calculation and aerodynamic design of the blade inlet geometry angle β 1c Deviation Δ 1c , that is, Δ 1c =β′ 1c -β 1c ; Extract the outlet geometric angle β′ of each section of the hot working blade 2c , calculation and aerodynamic design of the blade outlet geometry angle β 2c Deviation Δ 2c , that is, Δ 2c =β′ 2c -β 2c ; For n typical working conditions, the geometric angle deviation of the inlet and outlet under the first typical working condition is Δ 1c,1 , Δ 2c,1 , and so on, the geometric angle deviation of the inlet and outlet under the nth typical working condition is Δ 1c,n , Δ 2c,n ; (3) Correcting the blade modeling parameters: Based on the calculation results of the inlet and outlet geometric angle deviations, the inlet and outlet geometric angle parameters of the aerodynamic design moving blades are corrected and the blade modeling is performed again to obtain the corresponding transition state blades; (4) Perform three-dimensional CFD calculation and analysis of the compressor under typical working conditions, replace the corresponding moving blades in the aerodynamic design of the axial compressor with transitional blades, perform three-dimensional CFD calculation of the compressor as a whole under typical working conditions, return the calculation results to step (1) for static analysis, obtain the hot working blades of the transitional blades when the compressor is running under typical working conditions, and perform inlet and outlet geometric angle deviation calculation according to step (2); (5) Determine whether the pre-deformation design convergence condition is met, and judge the geometric angle deviation of the inlet and outlet of each shape section of the blade calculated in the previous step, and determine the Δ 1c , Δ 2c Whether the pre-deformation design convergence condition is met, if it is met, the transition state blade can be used as the expected processing blade for the next step; if not, Δ 1c , Δ 2c Return to step (3) and iterate until Δ 1c , Δ 2c Until the convergence condition is met; (6) Performing static analysis at a specific speed of the compressor, selecting a commonly used operating speed of the compressor as the specific speed, performing static analysis at each specific speed on the expected processing blade, and obtaining the hot working blade corresponding to the expected processing blade at each specific speed; (7) performing three-dimensional CFD calculation and analysis at a specific speed of the compressor, replacing the corresponding blades in the aerodynamic design of the axial compressor with the hot working blades corresponding to the expected processed blades at each specific speed, and performing three-dimensional CFD calculation and analysis at each specific speed. Through the three-dimensional CFD calculation, the performance and internal flow field conditions of the compressor at each specific speed are obtained to determine whether the performance requirements are met. If the performance requirements are met, the blade profile data of each section of the expected processed blade obtained in step (5) is used as the final processed blade profile data; If the performance requirements are not met, the convergence condition in step (5) is further reduced, and step (1) is returned to iterate according to the new convergence condition. Through repeated iterations, the final processing blade profile data of the axial compressor moving blade that finally meets the performance requirements is obtained.

2. A method for designing pre-deformation of moving blades of an axial compressor of a marine gas turbine according to claim 1, characterized in that: The moving blades that need to be pre-deformed in the aerodynamic design of the axial compressor described in step (1) are moving blades with a large deformation amount and a high incoming flow Mach number under the working state.

3. The method for designing the pre-deformation of the moving blades of the axial compressor of a marine gas turbine according to claim 1, characterized in that: The typical operating condition selected as the pre-deformation design operating condition in step (1) is the compressor design point and the near-surge point at 70% of the design speed as the typical operating condition.

4. The method for designing the pre-deformation of the moving blades of the axial compressor of a ship gas turbine according to claim 1, characterized in that: Based on the calculation result of the inlet and outlet geometric angle deviation described in step (3), the inlet and outlet geometric angle parameters of the moving blade of the aerodynamic design scheme are corrected in the following manner: The corrected inlet geometric angle of each section of the moving blade is calculated according to the following formula: The outlet geometry angle is calculated as follows: Where a and b are pre-deformation scaling coefficients, and a=1 and b=1 are initially taken.

5. The method for designing the pre-deformation of the moving blades of the axial compressor of a ship gas turbine according to claim 1, characterized in that: The convergence condition of the pre-deformation design described in step (5) is as follows: for n typical working conditions, the Δ of all the molding sections of the moving blades under all working conditions is 1c , Δ 2c All are no greater than 0.2°.

6. The method for designing the pre-deformation of the moving blades of the axial compressor of a ship gas turbine according to claim 1, characterized in that: The step (6) of selecting several commonly used operating speeds of the compressor as the specific speeds, for a ship gas turbine axial flow compressor, selects 4 to 5 characteristic operating speeds as the specific speeds within the range of 70% to 105% of the design speed.

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