Impact unit hydraulic characteristic curve generation method and system and readable storage medium

Abstract

The invention discloses an impact type unit hydraulic characteristic curve generation method and system and a readable storage medium. The method comprises the steps that the working water head and the rotating wheel diameter of a target water turbine are configured; configuring a plurality of working condition points, wherein the working condition points are used for indicating the nozzle needle opening degree and the rotating wheel rotating speed of the target water turbine; on the basis of the working water head and the diameter of the rotating wheel, the theoretical nozzle excess flow of each working condition point is iteratively updated, and the theoretical nozzle excess flow corresponding to the working water head under each working condition point is obtained; calculating characteristic parameters corresponding to the corresponding working condition points based on the theoretical nozzle excess flow; and fitting and generating a corresponding hydraulic characteristic curve based on the characteristic parameters corresponding to the working condition points. The method can quickly and accurately generate the water turbine full characteristic curve for hydropower station design and transition process calculation in the absence of model test data, and has the advantages of being high in calculation efficiency, excellent in precision and high in applicability.

Description

Technical Field

[0001] This invention relates to the field of hydropower station engineering technology, and in particular to a method, system, and readable storage medium for generating hydraulic characteristic curves of impulse turbine units. Background Technology

[0002] In the existing technology, the main methods for obtaining the hydraulic characteristics of impulse turbines include model testing and computational fluid dynamics numerical simulation.

[0003] Model testing requires physical modeling, multi-condition testing, and data correction, resulting in a long characteristic curve generation cycle. This cannot meet the need for rapid iteration in the preliminary design stage of hydropower stations. Furthermore, model data for specific parameters is often missing in the early stages of a project.

[0004] Although computational fluid dynamics numerical simulation is becoming increasingly mature, it still requires significant computational resources and expertise, and the computation process remains time-consuming.

[0005] Furthermore, as impulse turbines develop towards ultra-high head and large capacity, existing technologies, which address issues such as distorted physical test data for specific units leading to inaccurate simulations of the transient process, are no longer adequate for engineering design requirements. Summary of the Invention

[0006] The purpose of this invention is to provide a method for generating hydraulic characteristic curves specifically for the jet-runner interaction mechanism of impulse turbines, in order to solve the technical problem that existing technologies cannot quickly and accurately generate full characteristic curves of turbines for hydropower station design and transient process calculations when model test data is lacking.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] Firstly, a method for generating hydraulic characteristic curves of an impulse turbine unit is provided, comprising the following steps:

[0009] Configure the target turbine's operating head and runner diameter;

[0010] Several operating points are configured, which are used to indicate the nozzle opening and runner speed of the target water turbine;

[0011] Based on the working head and impeller diameter, the theoretical nozzle flow rate at each working point is iteratively updated to obtain the theoretical nozzle flow rate corresponding to the working head at each working point.

[0012] Based on the theoretical nozzle flow rate, calculate the characteristic parameters corresponding to the operating point.

[0013] The corresponding hydraulic characteristic curves are generated by fitting the characteristic parameters corresponding to each operating point.

[0014] This invention achieves precise point-by-point calculation of internal flow losses in impulse turbines by comparing theoretical head with operating head and iteratively adjusting the flow rate until convergence. This iterative mechanism, combined with fitting the full characteristic curve based on the convergent operating point, is not a simple transfer or adaptive modification of calculation methods for mixed-flow turbines, but rather a novel and dedicated theoretical calculation and iterative fitting technique specifically designed for the jet-runner interaction mechanism unique to impulse turbines. This method fills the technical gap in rapidly predicting the hydraulic characteristics of impulse turbines theoretically when model test data is lacking.

[0015] As one possible implementation method, the specific steps for iteratively calculating the theoretical nozzle flow rate at the current operating point are as follows:

[0016] Based on the nozzle opening and rotor speed corresponding to the current operating point, as well as the first nozzle flow rate, calculate the net water head corresponding to the current operating point, where the first nozzle flow rate is the initial nozzle flow rate or the second nozzle flow rate obtained in the previous iteration step.

[0017] Calculate the inlet impact head loss and the runner friction head loss, and calculate the total head loss based on the inlet impact head loss and the runner friction head loss;

[0018] The theoretical head is calculated based on the net head and the total head loss.

[0019] The direction and absolute difference of the difference are determined based on the theoretical head and the working head.

[0020] Whether convergence is determined based on the absolute difference:

[0021] When convergence is determined, the first nozzle flow rate is taken as the theoretical nozzle flow rate at the current operating point;

[0022] When convergence is not achieved, the first nozzle flow rate is optimized based on the difference direction to obtain the corresponding second nozzle flow rate, and the second nozzle flow rate is used as the first nozzle flow rate for the next iteration step.

[0023] As one possible implementation method, the specific steps for calculating the net water head corresponding to the current operating point, based on the nozzle opening and impeller speed, and the flow rate of the first nozzle, are as follows:

[0024] Determine the effective outflow area of ​​the nozzle based on the nozzle opening at the current operating point:

[0025] Based on the flow rate of the first nozzle, calculate the absolute jet velocity and the circumferential velocity at the current operating point;

[0026] Based on the absolute jet velocity and the rotational circumferential velocity, calculate the tangential component of the absolute jet velocity and the tangential component of the absolute outflow velocity:

[0027] The corresponding net head is calculated based on the tangential component of the absolute jet velocity and the tangential component of the absolute outflow velocity.

[0028] Existing methods for generating hydraulic characteristics of mixed-flow turbines have been proposed, but they are mostly based on the assumption of continuous flow within the flow channel and employ calculation modes that combine conformal transformation, flow channel segmentation, one-dimensional Euler equations, and head losses of various components. However, the working mechanism of impulse turbines is fundamentally different from that of mixed-flow turbines: impulse turbines rely on high-speed jets to impact the runner buckets, and the flow pattern is an intermittent interaction between free jets and discrete buckets. The energy conversion process is mainly manifested as the direct conversion of jet momentum into runner mechanical energy. Therefore, the core calculation elements in mixed-flow turbines are not applicable to impulse turbines.

[0029] This invention, targeting the energy conversion and internal flow characteristics of impulse turbines, proposes an original method for calculating net head and corresponding head loss, enabling the theoretical head and theoretical nozzle flow rate at each operating point obtained through iterative calculation to closely match reality, thereby obtaining accurate and effective hydraulic characteristic curves.

[0030] As one possible implementation method, the specific steps for determining convergence based on the absolute difference are as follows:

[0031] If the absolute difference is greater than the preset convergence tolerance, it is determined that the convergence has not occurred;

[0032] If the absolute difference is less than or equal to the preset convergence tolerance, the iteration is considered to have converged.

[0033] The convergence tolerance is set based on the working head.

[0034] As one possible implementation method, the configuration method for operating points is as follows:

[0035] Set several nozzle openings and several wheel speeds, and combine the nozzle openings and wheel speeds in pairs to obtain the corresponding operating points.

[0036] As one possible implementation method, the characteristic parameters include:

[0037] The characteristic parameters include the turbine's total efficiency, net output, unit speed, unit flow rate, and unit output at the corresponding operating points.

[0038] in:

[0039] Calculate the corresponding total turbine efficiency based on the obtained theoretical head and working head;

[0040] Calculate the corresponding net output based on the obtained theoretical nozzle flow rate and theoretical head;

[0041] Calculate the corresponding unit speed based on the obtained theoretical head, runner speed, and runner diameter;

[0042] Calculate the corresponding unit flow rate based on the obtained theoretical head, theoretical nozzle flow rate, and runner diameter;

[0043] Calculate the corresponding unit output based on the obtained theoretical head, runner diameter, and net output.

[0044] As one possible implementation method, based on the characteristic parameters corresponding to each operating point, the corresponding hydraulic characteristic curve of the impulse turbine is generated by fitting using the least squares method.

[0045] Secondly, a system for generating hydraulic characteristic curves for impulse turbine units is provided, comprising:

[0046] The user configuration module is used to configure the working head and runner diameter of the target turbine; it is also used to configure several operating points, which are used to indicate the nozzle opening and runner speed of the target turbine.

[0047] The iterative update module is used to iteratively update the theoretical nozzle flow rate at each operating point based on the working head and the impeller diameter, so as to obtain the theoretical nozzle flow rate corresponding to the working head at each operating point.

[0048] The calculation module is used to calculate the characteristic parameters corresponding to the corresponding operating point based on the theoretical nozzle flow rate.

[0049] The fitting module is used to fit and generate corresponding hydraulic characteristic curves based on the characteristic parameters corresponding to each operating point.

[0050] As one possible implementation, the iterative update module includes:

[0051] The head calculation unit is used to calculate the head corresponding to the current operating point based on the nozzle opening and wheel speed corresponding to the current operating point, as well as the first nozzle flow rate, where the first nozzle flow rate is the initial nozzle flow rate or the second nozzle flow rate obtained in the previous iteration step.

[0052] The loss calculation unit is used to calculate the inlet impact head loss and the runner friction head loss, and to calculate the total head loss based on the inlet impact head loss and the runner friction head loss;

[0053] The theoretical head calculation unit is used to calculate the theoretical head based on the net head and the total head loss;

[0054] The difference calculation unit is used to determine the direction and absolute difference of the difference based on the theoretical head and the working head.

[0055] The convergence determination unit is used to determine whether convergence has occurred based on the absolute difference; it is also used to take the first nozzle flow rate as the theoretical nozzle flow rate of the current operating point when convergence is determined; and it is also used to optimize the first nozzle flow rate based on the difference direction to obtain the corresponding second nozzle flow rate when convergence is determined not to have occurred, and take the second nozzle flow rate as the first nozzle flow rate of the next iteration step.

[0056] Thirdly, a computer-readable storage medium is provided, wherein a computer program is stored therein, and when the computer program is executed by a processor, it implements the method for generating hydraulic characteristic curves of impulse turbine units as described in any one of the above-mentioned methods.

[0057] This invention, by adopting the above technical solutions, has significant technical effects:

[0058] This invention achieves precise point-by-point calculation of internal flow losses in an impulse turbine by comparing theoretical head with operating head and iteratively adjusting the flow rate until convergence. The combination of this iterative mechanism and the fitting of the full characteristic curve based on the convergence point is not a simple superposition of existing technologies, but a dedicated algorithm designed specifically for the jet-runner interaction characteristics of impulse turbines. No existing technology has applied such an iterative convergence method to the generation of the full characteristic curve of an impulse turbine, nor has it disclosed a technical solution based on fitting isoefficiency curves using unit parameters. Therefore, the technical solution of this invention has outstanding substantive features and significant progress. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 This is a schematic flowchart of a method for generating hydraulic characteristic curves of an impulse turbine unit according to the present invention.

[0061] Figure 2 Schematic diagram of jet impact water bucket;

[0062] Figure 3 A schematic diagram of constructing a velocity triangle based on turbine parameters;

[0063] Figure 4 This is a schematic diagram of the velocity triangles at the inlet and outlet of a water turbine.

[0064] Figure 5This is a schematic diagram of the characteristic curves of an impulse turbine unit obtained in an example.

[0065] Figure 6 This is a comparison chart of the calculated characteristic curve results and the actual measured results of a real machine model in an example. Detailed Implementation

[0066] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0067] Example 1: This example provides a method for generating hydraulic characteristic curves of an impulse turbine unit. Taking a certain impulse turbine unit as an example, as follows... Figure 1 As shown, it includes the following steps:

[0068] S100, Configure the working head and runner diameter of the target turbine;

[0069] In practical applications, the runner and nozzle parameters of the target turbine are also configured according to actual needs.

[0070] The rotor parameters include: rotor diameter D1, rotor speed n, inlet angle β1, and outlet angle β2;

[0071] Nozzle parameters include: needle opening τ, maximum nozzle diameter d 1max .

[0072] S200: Configure several operating points, which are used to indicate the nozzle opening and runner speed of the target water turbine;

[0073] In this embodiment, several nozzle openings τ and several wheel rotation speeds n are set respectively. The nozzle openings τ and wheel rotation speeds n are combined in pairs to obtain the corresponding working points (τ, n).

[0074] S300. Based on the working head and impeller diameter, the theoretical nozzle flow rate at each working point is iteratively updated to obtain the theoretical nozzle flow rate corresponding to the working head at each working point.

[0075] The specific steps for iteratively calculating the theoretical nozzle flow rate at the current operating point are as follows:

[0076] S310. Calculate the net head corresponding to the current operating point;

[0077] This embodiment calculates the net water head corresponding to the current operating point based on the nozzle opening τ and the wheel speed n corresponding to the current operating point, as well as the first nozzle flow rate Q. The first nozzle flow rate is the initial nozzle flow rate or the second nozzle flow rate obtained in the previous iteration step.

[0078] The specific calculation steps are as follows:

[0079] S311. Determine the effective outflow area of ​​the nozzle based on the nozzle opening at the current operating point:

[0080] In this embodiment, as Figure 2 As shown, the formula for calculating the effective outflow area A(τ) of the nozzle is:

[0081]

[0082] Where τ is the nozzle opening, and d 1max This represents the maximum diameter of the nozzle.

[0083] S312. Based on the flow rate of the first nozzle, calculate the absolute jet velocity and the circumferential velocity at the current operating point;

[0084] The formula for calculating the absolute jet velocity V1 at the current operating point is:

[0085]

[0086] Where A(τ) is the effective outflow area of ​​the nozzle, and Q is the corresponding first nozzle flow rate;

[0087] The formula for calculating the circumferential velocity U of the wheel at the current operating point is:

[0088]

[0089] Where D1 is the diameter of the impeller and n is the rotational speed of the impeller.

[0090] S313. Based on the absolute jet velocity and the rotational circumferential velocity, and based on the velocity triangle, calculate the tangential component V of the absolute jet velocity. u1 tangential component of absolute outflow velocity V u2 :

[0091] The nozzle jet velocity triangle constructed based on the turbine parameters is as follows: Figure 3 As shown;

[0092] The velocity triangles at the inlet and outlet of a bucket turbine are as follows: Figure 4 As shown;

[0093] In this embodiment, the relative jet velocity W1 is calculated using a vector method, reflecting the relative motion relationship between the jet and the runner. This is the starting point for energy conversion in the impulse turbine. The vector calculation formula is as follows:

[0094]

[0095] in, It is a vector equation for the relative jet velocity. For absolute jet velocity vector equation, This is a vector equation for circumferential velocity. This embodiment is based on the momentum theorem, calculating the relative outflow velocity W2 based on the relative jet velocity W1. The calculation formula is:

[0096] W2 = kW1;

[0097] This loss model is specifically designed for flow inside impact buckets, and differs from the friction loss formula in mixed-flow systems.

[0098] Where k is the velocity coefficient, which is set to 0.98 in this embodiment to characterize friction loss; W1 is the relative jet velocity.

[0099] This embodiment calculates the absolute outflow velocity V2 based on the bucket geometry and the bucket outlet angle β2, and based on the relative outflow velocity W2:

[0100] That is, given the geometric outlet angle β2 of the water bucket, the absolute outflow velocity V2 is calculated using a vector formula, demonstrating the geometric guiding effect of the impact water bucket:

[0101]

[0102] in For absolute outflow velocity vector equation, This is a relative outflow velocity vector equation. It is a vector form of circumferential velocity.

[0103] In this embodiment, the first angle α1 between the absolute jet velocity V1 and the circumferential velocity U is obtained based on vector relationships. The second angle α2 between the absolute outflow velocity V2 and the circumferential velocity U can also be obtained based on vector relationships. The tangential component V of the absolute jet velocity V1 is then calculated based on the absolute jet velocity V1 and the first angle α1. u1 The tangential component V of the absolute outflow velocity is calculated based on the absolute outflow velocity V2 and the second included angle α2. u2 :

[0104] V u1 =V1*cosα1;

[0105] V u2 =V2*cosα2;

[0106] S314, Based on the tangential component of absolute jet velocity V u1 and the absolute outflow velocity tangential component V u2 Calculate the net head H1:

[0107] This embodiment establishes an Euler vortex equation applicable to impulse turbines. This equation directly reflects the process of the flow doing work on the runner, based on the tangential component V of the jet velocity. u1 and the absolute outflow velocity tangential component V u2 The net head H1 is calculated using the following formula:

[0108]

[0109] Or expressed as:

[0110]

[0111] Where: η s The turbine's hydraulic efficiency is given by ω, the runner's angular velocity is given by g, g is the acceleration due to gravity, r is the blade radius, and U is the circumferential velocity of the turbine.

[0112] S320, based on the import impact head loss H 撞 Head loss due to friction with the runner H f Calculate the total head loss H n ;

[0113] Total head loss H n The calculation formula is:

[0114] H n =H 撞 +H f ;

[0115] In this embodiment, the inlet impact head loss H 撞 The formula is:

[0116]

[0117] Where W1 is the relative jet velocity and β1 is the inlet angle of the inlet water bucket.

[0118] In this embodiment, the runner friction head loss H f The frictional effect of the jet on the water bucket surface is characterized by the following formula:

[0119]

[0120] Where V1 is the absolute jet velocity and V2 is the absolute outflow velocity.

[0121] S330. Calculate theoretical head based on net head and total head loss;

[0122] The theoretical head H0 is the sum of the net head H1 and the total head loss H. n The sum is calculated using the following formula:

[0123] H0 = H n +H1;

[0124] S340. Determine the direction of the difference and the absolute difference ΔH based on the theoretical head H0 and the working head H, ΔH=∣H0-H∣.

[0125] S350. Based on the absolute difference, determine whether convergence has occurred. If convergence is determined, use the first nozzle flow rate as the theoretical nozzle flow rate of the current operating point. If convergence is determined, optimize the first nozzle flow rate based on the difference direction to obtain the corresponding second nozzle flow rate. Use the second nozzle flow rate as the first nozzle flow rate of the next iteration step.

[0126] In this embodiment:

[0127] If the absolute difference ΔH is greater than the preset convergence tolerance ε, it is determined that the convergence has not been achieved.

[0128] If the absolute difference ΔH is less than or equal to the preset convergence tolerance ε, then the iteration is considered to have converged.

[0129] Those skilled in the art can set the convergence tolerance ε according to actual needs. In this embodiment, the convergence tolerance ε is 0.005H.

[0130] S400. Calculate the characteristic parameters corresponding to the corresponding operating point based on the theoretical nozzle flow rate.

[0131] The characteristic parameters include the turbine's total efficiency η, net output P, ​​and unit speed n at the corresponding operating point. 11 Unit flow rate Q 11 With unit output P 11 :

[0132] Unit rotational speed n 11 This refers to the turbine speed when the runner diameter is 1m and the water head is 1m.

[0133] Unit flow Q 11 This refers to the flow rate of the water turbine when the runner diameter is 1m and the water head is 1m;

[0134] Unit output P 11 This refers to the output of a water turbine when the runner diameter is 1m and the head is 1m.

[0135] S410. Calculate the overall efficiency η of the turbine based on the corresponding theoretical head H0 and working head H.

[0136] That is, η=H / H0.

[0137] S420. Calculate the corresponding net output force P based on the theoretical nozzle flow rate Q and the theoretical head H0.

[0138] That is, P = ρgQH0, where ρ is the density of water and g is the acceleration due to gravity.

[0139] S430. Calculate the unit rotational speed n based on the theoretical head H0, runner speed n, and runner diameter D1. 11 ;

[0140] Right now,

[0141] S440, Calculate the unit flow rate Q based on theoretical head H0, theoretical nozzle flow rate Q, and impeller diameter D1. 11 ;

[0142] Right now,

[0143] S450, based on theoretical head H0, impeller diameter D1, and net output P, ​​calculate unit output P. 11 :

[0144] Right now,

[0145] Where ω is the angular velocity of the wheel.

[0146] Based on the above steps, by iterating through different nozzle opening τ and runner speed n, the total turbine efficiency η, net output P, ​​and unit speed n that meet the iterative convergence condition at different operating points are calculated. 11 Unit flow rate Q 11 Unit output P 11 .

[0147] S500 generates hydraulic characteristic curves of impulse turbines by fitting characteristic parameters corresponding to each operating point.

[0148] This embodiment is based on the turbine's total efficiency η, net output P, ​​and unit speed n at each operating point. 11 Unit flow rate Q 11 Unit output P 11 The corresponding hydraulic characteristic curves of the impulse turbine are generated by fitting the curves using the least squares method.

[0149] Case Study:

[0150] In this case, the working head H = 834m and the runner diameter D1 = 4.766m;

[0151] The nozzle opening τ sequence is (0.25, 0.5, 0.75, 1.0);

[0152] The rotor speed n sequence is (0, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600) r / min;

[0153] Let each nozzle opening correspond to 13 rotation speed values, and combine them to obtain the corresponding operating points, that is, there are a total of 4×13=52 operating points (τ,n).

[0154] The characteristic curves of the corresponding impulse turbine unit are obtained according to the above-mentioned method for generating hydraulic characteristic curves of impulse turbine units, wherein the characteristic curves are... Figure 5 As shown;

[0155] To verify the consistency between the calculated unit characteristics and the actual unit characteristics, the hydraulic transient process was calculated using the calculated unit characteristics (this is a mature existing technology and will not be described in detail in this specification). The calculated results were then compared with the measured results. The results are as follows: Figure 6 As shown, the error of the calculation results is within 2%, which demonstrates that the method for generating hydraulic characteristic curves of impulse turbine units provided by this invention has high fidelity and accuracy.

[0156] In summary, this embodiment achieves precise point-by-point calculation of the internal flow losses of an impulse turbine by comparing the theoretical head with the operating head and iteratively adjusting the flow rate until convergence. This iterative mechanism, combined with fitting the full characteristic curve based on the convergence point, is not a simple transfer or adaptive modification of the calculation method for mixed-flow turbines, but rather a novel and dedicated theoretical calculation and iterative fitting technique specifically designed for the jet-runner interaction mechanism unique to impulse turbines. This method fills the technical gap in rapidly predicting the hydraulic characteristics of impulse turbines when model test data is lacking. Its core algorithm, loss model, iterative logic, and parameter system are fundamentally different from those of mixed-flow turbines, exhibiting significant substantive characteristics and remarkable progress.

[0157] Example 2, a hydraulic characteristic curve generation system for an impulse turbine unit, comprising:

[0158] The user configuration module is used to configure the working head and runner diameter of the target turbine; it is also used to configure several operating points, which are used to indicate the nozzle opening and runner speed of the target turbine.

[0159] The iterative update module is used to iteratively update the theoretical nozzle flow rate at each operating point based on the working head and the impeller diameter, so as to obtain the theoretical nozzle flow rate corresponding to the working head at each operating point.

[0160] The calculation module is used to calculate the characteristic parameters corresponding to the corresponding operating point based on the theoretical nozzle flow rate.

[0161] The fitting module is used to fit and generate corresponding hydraulic characteristic curves based on the characteristic parameters corresponding to each operating point.

[0162] As one possible implementation, the iterative update module includes:

[0163] The head calculation unit is used to calculate the head corresponding to the current operating point based on the nozzle opening and wheel speed corresponding to the current operating point, as well as the first nozzle flow rate, where the first nozzle flow rate is the initial nozzle flow rate or the second nozzle flow rate obtained in the previous iteration step.

[0164] The loss calculation unit is used to calculate the inlet impact head loss and the runner friction head loss, and to calculate the total head loss based on the inlet impact head loss and the runner friction head loss;

[0165] The theoretical head calculation unit is used to calculate the theoretical head based on the net head and the total head loss;

[0166] The difference calculation unit is used to determine the direction and absolute difference of the difference based on the theoretical head and the working head.

[0167] The convergence determination unit is used to determine whether convergence has occurred based on the absolute difference; it is also used to take the first nozzle flow rate as the theoretical nozzle flow rate of the current operating point when convergence is determined; and it is also used to optimize the first nozzle flow rate based on the difference direction to obtain the corresponding second nozzle flow rate when convergence is determined not to have occurred, and take the second nozzle flow rate as the first nozzle flow rate of the next iteration step.

[0168] Example 3: A computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method for generating hydraulic characteristic curves of an impulse turbine unit as described in Example 1.

[0169] As the device embodiment is basically similar to the method embodiment, the description is relatively simple, and relevant parts can be found in the description of the method embodiment.

[0170] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0171] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0172] This invention is described with reference to flowchart illustrations and / or block diagrams of the method, terminal device (system), and computer program product according to the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0173] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0174] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0175] It should be noted that:

[0176] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0177] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0178] Furthermore, it should be noted that the shapes and names of the parts and components described in the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles described in this patent concept are included within the protection scope of this patent. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not depart from the structure of this invention or exceed the scope defined in these claims, they should all fall within the protection scope of this invention.

Claims

1. A method for generating hydraulic characteristic curves of an impulse turbine unit, characterized in that, Includes the following steps: Configure the target turbine's operating head and runner diameter; Several operating points are configured, which are used to indicate the nozzle opening and runner speed of the target water turbine; Based on the working head and impeller diameter, the theoretical nozzle flow rate at each working point is iteratively updated to obtain the theoretical nozzle flow rate corresponding to the working head at each working point. Based on the theoretical nozzle flow rate, calculate the characteristic parameters corresponding to the operating point. The corresponding hydraulic characteristic curves are generated by fitting the characteristic parameters corresponding to each operating point.

2. The method for generating hydraulic characteristic curves of an impulse turbine unit according to claim 1, characterized in that, The specific steps for iteratively calculating the theoretical nozzle flow rate at the current operating point are as follows: Based on the nozzle opening and rotor speed corresponding to the current operating point, as well as the first nozzle flow rate, calculate the net water head corresponding to the current operating point, where the first nozzle flow rate is the initial nozzle flow rate or the second nozzle flow rate obtained in the previous iteration step. Calculate the inlet impact head loss and the runner friction head loss, and calculate the total head loss based on the inlet impact head loss and the runner friction head loss; The theoretical head is calculated based on the net head and the total head loss. The direction and absolute difference of the difference are determined based on the theoretical head and the working head. Whether convergence has been determined based on the absolute difference: When convergence is determined, the first nozzle flow rate is taken as the theoretical nozzle flow rate at the current operating point; When convergence is not achieved, the first nozzle flow rate is optimized based on the difference direction to obtain the corresponding second nozzle flow rate, and the second nozzle flow rate is used as the first nozzle flow rate for the next iteration step.

3. The method for generating hydraulic characteristic curves of an impulse turbine unit according to claim 2, characterized in that, Based on the nozzle opening and impeller speed corresponding to the current operating point, as well as the flow rate of the first nozzle, the specific steps for calculating the net water head corresponding to the current operating point are as follows: Determine the effective outflow area of ​​the nozzle based on the nozzle opening at the current operating point: Based on the flow rate of the first nozzle, calculate the absolute jet velocity and the circumferential velocity at the current operating point; Based on the absolute jet velocity and the rotational circumferential velocity, calculate the tangential component of the absolute jet velocity and the tangential component of the absolute outflow velocity: The corresponding net head is calculated based on the tangential component of the absolute jet velocity and the tangential component of the absolute outflow velocity.

4. The method for generating hydraulic characteristic curves of an impulse turbine unit according to claim 2, characterized in that, The specific steps for determining convergence based on the absolute difference are as follows: If the absolute difference is greater than the preset convergence tolerance, it is determined that the convergence has not occurred; If the absolute difference is less than or equal to the preset convergence tolerance, the iteration is considered to have converged. The convergence tolerance is set based on the working head.

5. The method for generating hydraulic characteristic curves of an impulse turbine unit according to claim 1, characterized in that, The configuration method for operating points is as follows: Set several nozzle openings and several wheel speeds, and combine the nozzle openings and wheel speeds in pairs to obtain the corresponding operating points.

6. The method for generating hydraulic characteristic curves of an impulse turbine unit according to claim 1, characterized in that, The characteristic parameters include: The characteristic parameters include the turbine's total efficiency, net output, unit speed, unit flow rate, and unit output at the corresponding operating points. in: Calculate the corresponding total turbine efficiency based on the obtained theoretical head and working head; Calculate the corresponding net output based on the obtained theoretical nozzle flow rate and theoretical head; Calculate the corresponding unit speed based on the obtained theoretical head, runner speed, and runner diameter; Calculate the corresponding unit flow rate based on the obtained theoretical head, theoretical nozzle flow rate, and runner diameter; Calculate the corresponding unit output based on the obtained theoretical head, runner diameter, and net output.

7. The method for generating hydraulic characteristic curves of an impulse turbine unit according to claim 1, characterized in that, Based on the characteristic parameters corresponding to each operating point, the corresponding hydraulic characteristic curves of the impulse turbine are generated by fitting using the least squares method.

8. A system for generating hydraulic characteristic curves of an impulse turbine unit, characterized in that, include: The user configuration module is used to configure the target turbine's operating head and runner diameter. It is also used to configure several operating points, which are used to indicate the nozzle opening and runner speed of the target turbine. The iterative update module is used to iteratively update the theoretical nozzle flow rate at each operating point based on the working head and the impeller diameter, so as to obtain the theoretical nozzle flow rate corresponding to the working head at each operating point. The calculation module is used to calculate the characteristic parameters corresponding to the corresponding operating point based on the theoretical nozzle flow rate. The fitting module is used to fit and generate corresponding hydraulic characteristic curves based on the characteristic parameters corresponding to each operating point.

9. The hydraulic characteristic curve generation system for an impulse turbine unit according to claim 8, characterized in that, The iterative update module includes: The head calculation unit is used to calculate the head corresponding to the current operating point based on the nozzle opening and rotor speed corresponding to the current operating point, as well as the first nozzle flow rate, where the first nozzle flow rate is the initial nozzle flow rate or the second nozzle flow rate obtained in the previous iteration step. The loss calculation unit is used to calculate the inlet impact head loss and the runner friction head loss, and to calculate the total head loss based on the inlet impact head loss and the runner friction head loss; The theoretical head calculation unit is used to calculate the theoretical head based on the net head and the total head loss; The difference calculation unit is used to determine the direction and absolute difference of the difference based on the theoretical head and the working head. The convergence determination unit is used to determine whether convergence has occurred based on the absolute difference; it is also used to take the first nozzle flow rate as the theoretical nozzle flow rate of the current operating point when convergence is determined; and it is also used to optimize the first nozzle flow rate based on the difference direction to obtain the corresponding second nozzle flow rate when convergence is determined not to have occurred, and take the second nozzle flow rate as the first nozzle flow rate of the next iteration step.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the method for generating hydraulic characteristic curves of an impulse turbine as described in any one of claims 1 to 7.

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