Optimization design method for transcritical carbon dioxide centrifugal pump impeller

Abstract

The invention relates to an optimization design method for a transcritical carbon dioxide centrifugal pump impeller. The method comprises the steps that main structure parameters of an impeller are determined based on existing impeller parameters obtained in advance and the specific speed of the impeller; determining meridian flow channel linear parameters of the impeller based on the main structure parameters and a meridian plane overflowing section area change diagram, a wheel disc meridian molded line static moment change diagram and a wheel cover meridian molded line static moment change diagram which are obtained in advance; determining initial three-dimensional design parameters of the impeller based on a centrifugal impeller non-stick quasi-three-dimensional potential flow theory algorithm, the main structure parameters and the meridian flow channel linear parameters; and importing the preliminary three-dimensional design parameters into a preset blade hydraulic optimization algorithm model to obtain optimal blade design parameters, and performing simulation based on the optimal blade design parameters to obtain an optimal impeller shape. According to the method, the dependence of a user on specific centrifugal impeller design experience is weakened, the method is suitable for hydraulic design of the transcritical carbon dioxide centrifugal pump impeller, and the centrifugal pump impeller determined through the optimization design method has good efficiency and pressurization effect.

Description

Technical Field

[0001] The present application relates to the field of centrifugal pumps, and in particular to an optimization design method for a transcritical carbon dioxide centrifugal pump impeller. Background Art

[0002] As the main boosting component of the CO2 power / power generation system, the transcritical CO2 centrifugal pump usually has the performance characteristics of high head (several thousand meters) and high speed (tens of thousands of revolutions per minute), and the centrifugal impeller, as the only working component in the centrifugal pump, undertakes the main boosting task. The performance requirements of high head and high speed place high demands on the hydraulic design capabilities of the impeller. The traditional impeller hydraulic design method is mainly based on a large amount of experience accumulated in a specific application scenario. However, for the new field of transcritical CO2 power cycle, it is urgent to establish a new and effective hydraulic design and optimization method based on the inheritance of traditional hydraulic design methods.

[0003] At present, most hydraulic design methods for impellers follow the basic process of "determining the design point - selecting the main structural parameters - designing the meridian flow profile - blade three-dimensional design - simulation / experimental verification". The three-dimensional blade design stage is mainly based on a large amount of industry design experience to directly control the blade installation angle. This type of blade design method is called direct problem design. However, at present, there are not many mature design cases and industry design experience for the design optimization of transcritical carbon dioxide centrifugal pump impellers. The blade design optimization methods provided in related technologies have limitations and cannot be applied to transcritical carbon dioxide centrifugal pump impellers. Summary of the invention

[0004] The present application provides an optimization design method for a transcritical carbon dioxide centrifugal pump impeller, so as to at least solve the problem that the blade design optimization method provided in the related art has limitations and cannot be applied to the transcritical carbon dioxide centrifugal pump impeller.

[0005] In a first aspect, the present application provides a method for optimizing the design of a transcritical carbon dioxide centrifugal pump impeller, the method comprising:

[0006] Determine the main structural parameters of the impeller based on the existing impeller parameters and impeller specific speed acquired in advance;

[0007] Determine the linear parameters of the meridian flow passage of the impeller based on the main structural parameters and the pre-acquired meridian plane flow cross-sectional area change diagram, the impeller plate meridian line static moment change diagram and the impeller cover meridian line static moment change diagram;

[0008] Determine the preliminary three-dimensional design parameters of the impeller based on the centrifugal impeller inviscid quasi-three-dimensional potential flow theory algorithm, the main structural parameters and the meridian flow channel linear parameters;

[0009] The preliminary three-dimensional design parameters are imported into a preset blade hydraulic optimization algorithm model to obtain optimal blade design parameters, and an optimal impeller shape is obtained by simulation based on the optimal blade design parameters.

[0010] Optionally, the main structural parameters include: impeller inlet hub radius, impeller inlet wheel cover radius, impeller outlet radius and impeller outlet width.

[0011] Optionally, determining the main structural parameters of the impeller based on the pre-acquired existing impeller parameters and the impeller specific speed includes:

[0012] Based on the existing impeller parameters, the impeller specific speed is defined, the change of the impeller specific speed within a preset range is adjusted, and a design parameter set of the impeller is obtained, wherein the design parameters include the impeller design point flow rate, the impeller head and the impeller speed;

[0013] Preprocessing the design parameter set to obtain an optimal specific speed of the impeller;

[0014] The optimal specific speed is introduced into a preset centrifugal impeller design formula to calculate and obtain the main structural parameters of the impeller.

[0015] Optionally, the preprocessing includes data denoising and data screening.

[0016] Optionally, the meridian flow channel linear parameters include: disk meridian profile design parameters, wheel cover meridian profile design parameters and blade meridian leading edge design parameters.

[0017] Optionally, the importing of the three-dimensional shape parameters into a preset blade hydraulic optimization algorithm model to obtain optimal blade shape parameters includes:

[0018] According to the pre-selected blade hydraulic optimization algorithm model, the parameterized impeller disk load control parameters, the impeller cover blade load control parameters and the number of blades are used as optimization independent variables, the impeller blade loss and secondary flow loss are defined as optimization objectives, and multi-objective optimization is performed to obtain the optimal blade shape parameters.

[0019] In a second aspect, the present application provides an optimization design system for a transcritical carbon dioxide centrifugal pump impeller, the system comprising:

[0020] A first calculation module determines the main structural parameters of the impeller based on the pre-acquired existing impeller parameters and the impeller specific speed;

[0021] A second calculation module determines the linear parameters of the meridian flow passage of the impeller based on the pre-acquired meridian plane flow cross-sectional area change diagram, the impeller plate meridian line static moment change diagram and the impeller cover meridian line static moment change diagram;

[0022] A design module, which determines preliminary three-dimensional design parameters of the impeller based on a centrifugal impeller inviscid quasi-three-dimensional potential flow theory algorithm, the main structural parameters and the meridian flow channel linear parameters;

[0023] The optimization module imports the preliminary three-dimensional design parameters into a preset blade hydraulic optimization algorithm model to obtain optimal blade design parameters, and obtains an optimal impeller shape based on the optimal blade design parameters through simulation.

[0024] In a third aspect, the present application provides an electronic device, characterized in that it includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the optimization design method for the impeller of a transcritical carbon dioxide centrifugal pump provided in the first aspect is implemented.

[0025] In a fourth aspect, the present application provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the optimization design method for a transcritical carbon dioxide centrifugal pump impeller provided in the first aspect above.

[0026] Compared with the related art, the optimization design method of a transcritical carbon dioxide centrifugal pump impeller provided in this application has at least the following technical effects:

[0027] The main structural parameters of the impeller are determined based on the pre-acquired existing impeller parameters and impeller specific speed; the linear parameters of the meridian flow channel of the impeller are determined based on the main structural parameters, as well as the pre-acquired meridian plane flow cross-sectional area change diagram, the impeller plate meridian profile static moment change diagram and the impeller cover meridian profile static moment change diagram; the preliminary three-dimensional design parameters of the impeller are determined based on the centrifugal impeller inviscid quasi-three-dimensional potential flow theory algorithm, the main structural parameters and the meridian flow channel linear parameters; the preliminary three-dimensional design parameters are imported into the preset blade hydraulic optimization algorithm model to obtain the optimal blade design parameters; the user's dependence on the design experience of a specific type of centrifugal impeller is weakened, and it is suitable for the hydraulic design of the transcritical carbon dioxide centrifugal pump impeller. The centrifugal pump impeller determined by the optimization design method has good efficiency and boosting effect.

[0028] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0030] Figure 1is a flow chart of an optimization design method for a transcritical carbon dioxide centrifugal pump impeller according to an exemplary embodiment;

[0031] Figure 2 is a diagram showing the main structural parameters of the impeller in step S101 and the meridian flow channel in step 102 according to an exemplary embodiment;

[0032] Figure 3 is a flowchart of step S101 according to an exemplary embodiment;

[0033] Figure 4 is a diagram showing a change in the flow cross-sectional area of ​​a meridian plane of an impeller according to an exemplary embodiment;

[0034] Figure 5 is a diagram showing a change in static moment of the impeller disc and impeller cover meridian line of an impeller according to an exemplary embodiment;

[0035] Figure 6 is a schematic diagram of blade load definition of an impeller according to an exemplary embodiment;

[0036] Figure 7 is a diagram showing a variation of a blade installation angle of an impeller according to another exemplary embodiment;

[0037] Figure 8 are two three-dimensional modeling diagrams of an impeller according to another exemplary embodiment;

[0038] Fig. 9 is a distribution diagram of multi-objective optimization results of impeller blades according to another exemplary embodiment;

[0039] Fig.10 is a comparison diagram of blade load parameters after multi-objective optimization of an impeller according to another exemplary embodiment;

[0040] Fig.11 are two representative optimized three-dimensional comparison diagrams of an impeller according to another exemplary embodiment;

[0041] Fig.12 is a block diagram of an optimization design system for a transcritical carbon dioxide centrifugal pump impeller according to an exemplary embodiment. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0043] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0044] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0045] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0046] In the related technologies, the hydraulic design methods for impellers currently mostly follow the basic process of "determining the design point - selecting the main structural parameters - designing the meridian flow profile - blade three-dimensional design - simulation / experimental verification". The three-dimensional blade design stage is mainly based on a large amount of industry design experience to directly control the blade installation angle. This type of blade design method is called positive problem design. However, the design optimization of transcritical carbon dioxide centrifugal pump impellers has not yet established a large number of mature design cases and industry design experience. The blade design optimization methods provided in the related technologies have limitations and cannot be applied to transcritical carbon dioxide centrifugal pump impellers.

[0047] Based on the above situation, an embodiment of the present invention provides an optimization design method for a transcritical carbon dioxide centrifugal pump impeller, which is described in detail below in conjunction with specific embodiments and drawings.

[0048] Example 1

[0049] An embodiment of the present invention provides a method for optimizing the design of a transcritical carbon dioxide centrifugal pump impeller. Figure 1 FIG. 1 is a flow chart of an optimization design method for a transcritical carbon dioxide centrifugal pump impeller according to an exemplary embodiment. Figure 1 As shown, the method includes:

[0050] S101. Determine the main structural parameters of the impeller based on the pre-acquired existing impeller parameters and the impeller specific speed; wherein the main structural parameters include: impeller inlet hub radius, impeller inlet wheel cover radius, impeller outlet radius and impeller outlet width. Figure 2 is a schematic diagram of the main structural parameters of the impeller in step S101 and the meridian flow channel in step 102 according to an exemplary embodiment; Figure 2 , where R1h represents the inlet hub radius, R1s represents the inlet wheel cover radius, R2 represents the outlet radius, and b2 represents the outlet width.

[0051] In this embodiment, Figure 3 is a flowchart of step S101 according to an exemplary embodiment; Figure 3 , step S101 includes:

[0052] S1011. Based on existing impeller parameters, define an impeller specific speed, adjust the change of the impeller specific speed within a preset range, and obtain a design parameter set of the impeller, wherein the design parameters include an impeller design point flow rate, an impeller head, and an impeller speed;

[0053] S1012. Preprocess the design parameter set to obtain the optimal specific speed of the impeller; wherein the preprocessing includes data noise reduction and data screening.

[0054] S1013, importing the optimal specific speed into a preset centrifugal impeller design formula, and calculating and obtaining the main structural parameters of the impeller. In this embodiment, the preset centrifugal impeller design formula is a one-dimensional general design formula for centrifugal impellers.

[0055] The following is an example of a typical transcritical carbon dioxide single-stage centrifugal impeller with a national standard specific speed of 50. The main structural parameters of the impeller design are shown in Table 1:

[0056]

[0057]

[0058] Table 1

[0059] Combined with Table 1, Appendix Figure 2 and attached Figure 3 , with the help of the one-dimensional general design formula of centrifugal impeller, the main structural parameters of the impeller are determined: inlet hub radius R1h = 21mm, inlet wheel cover radius R1s = 35mm, outlet radius R2 = 79mm and outlet width b2 = 4mm.

[0060] S102. Determine the linear parameters of the meridian flow passage of the impeller based on the main structural parameters and the pre-acquired meridian plane flow cross-sectional area change diagram, the impeller disk meridian profile static moment change diagram and the impeller cover meridian profile static moment change diagram; wherein the meridian flow passage linear parameters include: impeller disk meridian profile design parameters, impeller cover meridian profile design parameters and blade meridian leading edge design parameters.

[0061] Figure 4 is a diagram showing a change in the flow cross-sectional area of ​​a meridian plane of an impeller according to an exemplary embodiment; Figure 5 is a diagram showing the change of the meridian line static moment of the impeller disc and impeller cover according to an exemplary embodiment; Figure 4-5 Based on the main structural parameters and the pre-acquired meridian plane flow cross-sectional area change diagram, the meridian profile corresponding to the linear change trend of the flow cross-sectional area is obtained; at the same time, the static moment change diagram of the impeller plate meridian profile and the static moment change diagram of the impeller cover meridian profile of the impeller are monitored, and the leading edge position of the blade is adjusted and designed to ensure that the static moments of the two at the trailing edges are similar, thus completing the linear parameters of the impeller meridian flow channel.

[0062] S103, determining preliminary three-dimensional design parameters of the impeller based on the centrifugal impeller inviscid quasi-three-dimensional potential flow theory algorithm, main structural parameters and meridian flow channel linear parameters;

[0063] In this embodiment, according to the pre-selected blade hydraulic optimization algorithm model, the parameterized impeller disk load control parameter, the impeller cover blade load control parameter and the number of blades are used as optimization independent variables, the impeller blade loss and the secondary flow loss are defined as optimization targets, and multi-objective optimization is performed to obtain the optimal blade shape parameters;

[0064] In this embodiment, the blade inverse problem design uses the selected blade hydraulic optimization algorithm model:

[0065] The "Zangeneh-Goto method" is based on potential flow theory. It establishes a set of equations that relate the flow field characteristics of the blade channel and the blade geometric parameters, and uses the blade load parameters and blade stack conditions as the solution conditions to ultimately achieve an iterative solution of the blade shape.

[0066] Specifically, Figure 6 is a schematic diagram of blade load definition of an impeller according to an exemplary embodiment; Figure 7 is a diagram showing a variation of a blade installation angle of an impeller according to another exemplary embodiment; Figure 8 are two three-dimensional modeling diagrams of an impeller according to another exemplary embodiment; Figure 6-8 , the blade installation angle, i.e. the blade geometry, is controlled by defining the blade load parameters. Figure 6 As shown in the figure, the blade load variation curve on each blade profile consists of two parabolas at the beginning and end and a straight line in the middle. The corresponding blade load parameters are: NC, ND (the intersection of the parabola and the straight line) and slope (the slope of the straight line). The blade shape is controlled by two sets of blade load parameters of the wheel disc and wheel cover profile plus the number of blades, a total of 7 variables. Each parameter has a certain range of variation. Please refer to the attached Figure 8 ,The appropriate parameter combination finally generates a blade shape that meets certain performance requirements for further simulation and experimental research.

[0067] S104, importing the preliminary three-dimensional design parameters into a preset blade hydraulic optimization algorithm model to obtain optimal blade design parameters, and simulating based on the optimal blade design parameters to obtain an optimal impeller shape.

[0068] In this embodiment, Fig. 9 is a distribution diagram of multi-objective optimization results of impeller blades according to another exemplary embodiment; Fig.10 is a comparison diagram of blade load parameters after multi-objective optimization of an impeller according to another exemplary embodiment; Fig.11 2 are two representative optimized three-dimensional comparison diagrams of an impeller according to another exemplary embodiment. Figure 9-11,The preset blade hydraulic optimization algorithm model is based on the NSGA-Ⅱ algorithm, taking the blade load parameters and the number of blades as the optimization independent variables, defining the blade profile loss and the secondary flow loss as the optimization targets, and performing multi-objective optimization, where the optimization independent variable table is shown in Table 2;

[0069]

[0070]

[0071] Table 2

[0072] Referring to Table 2, H represents the impeller disk, S represents the impeller cover, and the multi-objective optimization settings are: the population size is 100, the number of iterations is 100, the crossover probability is 0.9, and the mutation probability is 0.088. That is, the "ZG method" is iteratively calculated for 10,000 blade schemes, and finally 7,473 convergent schemes are obtained. The blade loss and secondary flow loss of each convergent blade are calculated and plotted to form Fig. 9 The distribution diagram of the multi-objective optimization results of the impeller blades, attached Fig. 9 The blade scheme at the lower left boundary shown is the Pareto frontier scheme with the smallest comprehensive loss, and can be used as a recommended blade scheme for further simulation and experimental testing;

[0073] Then, based on Table 2, the convergence results with secondary flow loss less than 0.005 were selected, and the blade loss was used as the horizontal axis to plot the attached Fig.10 Comparison of blade load parameters after multi-objective optimization of the impeller. Two sets of blade load parameters are selected from the above data to form the following Table 3

[0074]

[0075]

[0076] Table 3

[0077] Referring to the data shown in Table 3, the two impeller models are meshed discretized with the help of CFD simulation software and steady-state solution calculations are performed under design conditions. After mesh independence verification, the corresponding blade three-dimensional geometry is obtained, namely, Fig.11 Two representative optimized three-dimensional comparison diagrams of the impeller are shown, and then the performance parameters of the two impeller design points are solved. The comparison results are shown in Table 4:

[0078] Performance parameters Impeller A Impeller B Outlet static pressure / Mpa 14.4718 15.0903 Total outlet pressure / Mpa 19.8762 21.3516 Hydraulic efficiency 0.935 0.969

[0079] Table 4

[0080] Referring to Appendix 4, it can be seen from the comparison that both representative impellers can meet the design boosting requirements, and different impellers have significantly different efficiencies and boosting capabilities. Therefore, the optimization design method for the transcritical carbon dioxide centrifugal pump impeller proposed in the embodiment of the present application has reliability and potential for further promotion and application.

[0081] In summary, the optimization design method for the impeller of a transcritical carbon dioxide centrifugal pump provided in Example 1 of the present invention weakens the user's dependence on the design experience of a specific type of centrifugal impeller, and conveniently obtains a series of guiding impeller three-dimensional models to facilitate further simulation or experimental research in the future. It is suitable for the hydraulic design of the impeller of a transcritical carbon dioxide centrifugal pump. The centrifugal pump impeller determined by the optimization design method has good efficiency and boosting effect.

[0082] Example 2

[0083] Example 2 of the present application provides an optimization design system for a transcritical carbon dioxide centrifugal pump impeller. Fig.12 FIG. 1 is a block diagram of an optimization design system for a transcritical carbon dioxide centrifugal pump impeller according to an exemplary embodiment. Fig.12 , the system includes:

[0084] A first calculation module 201 determines the main structural parameters of the impeller based on the pre-acquired existing impeller parameters and the impeller specific speed;

[0085] The second calculation module 202 determines the linear parameters of the meridian flow passage of the impeller based on the pre-acquired meridian plane flow cross-sectional area variation diagram, the impeller plate meridian line static moment variation diagram and the impeller cover meridian line static moment variation diagram;

[0086] Design module 203, determining preliminary three-dimensional design parameters of the impeller based on the centrifugal impeller inviscid quasi-three-dimensional potential flow theory algorithm, main structural parameters and meridian flow channel linear parameters;

[0087] The optimization module 204 imports the preliminary three-dimensional design parameters into a preset blade hydraulic optimization algorithm model to obtain the optimal blade design parameters, and obtains the optimal impeller shape based on the optimal blade design parameters through simulation.

[0088] In summary, the optimization design system for the impeller of a transcritical carbon dioxide centrifugal pump provided in Example 2 of the present invention weakens the user's dependence on the design experience of a specific type of centrifugal impeller, and conveniently obtains a series of guiding impeller three-dimensional models to facilitate further simulation or experimental research. It is suitable for the hydraulic design of the impeller of a transcritical carbon dioxide centrifugal pump. The centrifugal pump impeller determined by the optimization design method has good efficiency and boosting effect.

[0089] Example 3

[0090] Embodiment 3 of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the optimization design method for the impeller of a transcritical carbon dioxide centrifugal pump provided in the first aspect above is implemented.

[0091] Example 4

[0092] Embodiment 4 of the present invention provides a computer-readable storage medium having a program stored thereon. When the program is executed by a processor, the optimization design method for the impeller of a transcritical carbon dioxide centrifugal pump provided in the first aspect above is implemented.

[0093] The readable storage medium may include but is not limited to: a portable disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical storage device, a magnetic storage device or any suitable combination of the above.

[0094] In a possible implementation manner, the present invention can also be implemented in the form of a program product, which includes a program code. When the program product is run on a terminal device, the program code is used to enable the terminal device to execute the steps of the optimization design method for the impeller of a transcritical carbon dioxide centrifugal pump in Example 1.

[0095] Among them, the program code for executing the present invention can be written in any combination of one or more programming languages, and the program code can be executed completely on the user device, partially on the user device, as an independent software package, partially on the user device and partially on a remote device, or completely on the remote device.

[0096] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for optimizing the design of a transcritical carbon dioxide centrifugal pump impeller, characterized in that: The method comprises: Determine the main structural parameters of the impeller based on the existing impeller parameters and impeller specific speed acquired in advance; Determine the linear parameters of the meridian flow passage of the impeller based on the main structural parameters and the pre-acquired meridian plane flow cross-sectional area change diagram, the impeller plate meridian line static moment change diagram and the impeller cover meridian line static moment change diagram; Determine the preliminary three-dimensional design parameters of the impeller based on the centrifugal impeller inviscid quasi-three-dimensional potential flow theory algorithm, the main structural parameters and the meridian flow channel linear parameters; The preliminary three-dimensional design parameters are imported into a preset blade hydraulic optimization algorithm model to obtain optimal blade design parameters, and an optimal impeller shape is obtained by simulation based on the optimal blade design parameters.

2. The optimization design method according to claim 1, characterized in that: The main structural parameters include: impeller inlet hub radius, impeller inlet wheel cover radius, impeller outlet radius and impeller outlet width.

3. The optimization design method according to claim 1, characterized in that: The method of determining the main structural parameters of the impeller based on the pre-acquired existing impeller parameters and the impeller specific speed comprises: Based on the existing impeller parameters, the impeller specific speed is defined, the change of the impeller specific speed within a preset range is adjusted, and a design parameter set of the impeller is obtained, wherein the design parameters include the impeller design point flow rate, the impeller head and the impeller speed; Preprocessing the design parameter set to obtain an optimal specific speed of the impeller; The optimal specific speed is introduced into a preset centrifugal impeller design formula to calculate and obtain the main structural parameters of the impeller.

4. The optimization design method according to claim 3, characterized in that: The preprocessing includes data noise reduction and data screening.

5. The optimization design method according to claim 1, characterized in that: The meridian flow channel linear parameters include: disk meridian profile design parameters, wheel cover meridian profile design parameters and blade meridian front edge design parameters.

6. The optimization design method according to claim 1, characterized in that: The step of importing the three-dimensional shape parameters into a preset blade hydraulic optimization algorithm model to obtain optimal blade shape parameters includes: According to the pre-selected blade hydraulic optimization algorithm model, the parameterized impeller disk load control parameters, the impeller cover blade load control parameters and the number of blades are used as optimization independent variables, the impeller blade loss and secondary flow loss are defined as optimization objectives, and multi-objective optimization is performed to obtain the optimal blade shape parameters.

7. An optimization design system for a transcritical carbon dioxide centrifugal pump impeller, characterized in that: The system comprises: A first calculation module determines the main structural parameters of the impeller based on the pre-acquired existing impeller parameters and the impeller specific speed; A second calculation module determines the linear parameters of the meridian flow passage of the impeller based on the pre-acquired meridian plane flow cross-sectional area change diagram, the impeller plate meridian line static moment change diagram and the impeller cover meridian line static moment change diagram; A design module, which determines preliminary three-dimensional design parameters of the impeller based on a centrifugal impeller inviscid quasi-three-dimensional potential flow theory algorithm, the main structural parameters and the meridian flow channel linear parameters; The optimization module imports the preliminary three-dimensional design parameters into a preset blade hydraulic optimization algorithm model to obtain optimal blade design parameters, and obtains an optimal impeller shape based on the optimal blade design parameters through simulation.

8. An electronic device, characterized in that: include: Memory, processor, and A computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for optimizing the design of the impeller of a transcritical carbon dioxide centrifugal pump according to any one of claims 1 to 7 is implemented.

9. A computer-readable storage medium, characterized in that: A program is stored thereon, and when the program is executed by a processor, the optimization design method for the impeller of a transcritical carbon dioxide centrifugal pump according to any one of claims 1 to 7 is implemented.

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