One-dimensional and three-dimensional heterogeneous step coupling simulation method and device for multi-nozzle bucket type hydraulic turbine

Abstract

The application discloses a one-dimensional and three-dimensional heterogeneous time step coupling simulation method and device for a multi-nozzle bucket-type hydraulic turbine. The method comprises the following steps: establishing a calculation model of a one-dimensional system and a three-dimensional system of the multi-nozzle bucket-type hydraulic turbine; determining a transient calculation time step of the one-dimensional system and the three-dimensional system; calculating initial states and an initial flow field of the one-dimensional system and the three-dimensional system; determining whether the one-dimensional system and the three-dimensional system meet a heterogeneous time step coupling discrimination relationship; if the current time step meets the heterogeneous time step coupling discrimination relationship, one-dimensional and three-dimensional heterogeneous time step coupling simulation calculation is performed; if not, three-dimensional system simulation calculation is performed; until the calculation converges; one-dimensional and three-dimensional system calculation data is output and stored, and the calculation at the current time is completed; until the calculation at a preset time step is completed. The method can meet the accuracy requirement of transient calculation of the bucket-type hydraulic turbine, can comprehensively consider the calculation efficiency of the large-scale time step of the one-dimensional system, and further improves the calculation accuracy and speed of the power regulation process of the multi-nozzle bucket-type hydraulic turbine.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of dynamic modeling and model simulation in the power regulation process of a hydroelectric station water turbine, and particularly relates to a one-dimensional three-dimensional heterogeneous step coupling simulation calculation method and device for a multi-nozzle bucket-type water turbine. BACKGROUND

[0002] Bucket-type water turbines have become the preferred model for the development of water energy resources in high-altitude regions due to their advantages such as adaptability to high operating water head, relatively stable unit efficiency, and wide operating range. Bucket-type water turbines generally increase the number of nozzles to improve the unit capacity and operating efficiency of the unit. However, the increase in the number of nozzles may exacerbate the mutual interference of water flow within the runner, thereby reducing the hydraulic efficiency of the unit. In addition, during the power regulation process of a bucket-type water turbine, due to the increase in the number of nozzles, in order to better regulate the flow, the mutual switching of multiple nozzles is often involved. During the nozzle switching process, the mutual action of the nozzles may cause uneven stress and speed fluctuations of the runner, exacerbating the complexity of the internal flow of the runner, and thereby affecting the safe and stable operation of the unit.

[0003] Currently, the one-dimensional characteristic line method (MOC) and computational fluid dynamics (CFD) can be used to carry out simulation calculations of multi-nozzle bucket-type water turbines. Among them, MOC can use a large-scale time step to simplify the water flow in the water delivery system pressure pipeline as a unidirectional flow, and use a mathematical model to describe the reservoir, surge chamber, and bifurcated pipe structures; the water turbine is treated as a boundary point, and the static characteristic curve is used for unit transition process calculation. MOC can efficiently and quickly simulate the transition process of a bucket-type water turbine, obtaining the macroscopic parameter changes of the transition process, but does not consider the dynamic characteristics of the unit and the deterioration of the flow pattern caused by nozzle switching and other three-dimensional problems. In recent years, CFD has become an efficient means for studying the internal flow of multi-nozzle bucket-type water turbines. Through three-dimensional numerical simulation, researchers have discovered the water flow interference phenomenon and its formation mechanism in the bucket-type water turbine, the uneven flow distribution and formation mechanism in the distribution ring pipe, and the jet flow deflection and other hydraulic phenomena. However, due to the limitation of the Courant number, in order to accurately capture the gas-liquid interface within the three-dimensional grid, CFD needs to use a very small time step for calculation. This makes CFD have the problems of long calculation time and the need for a large amount of computing resources.

[0004] Currently, there is little research on the coupling simulation calculation of one-dimensional system and three-dimensional multi-nozzle bucket-type hydraulic turbine. One of the reasons is that there is no method for coupling connection of different time steps of one-dimensional system and three-dimensional system. If the one-dimensional system and the three-dimensional system both use the large time step of the one-dimensional system, the CFD will diverge when calculating the gas-liquid two-phase flow; if the one-dimensional system and the three-dimensional system both use the small time step of the three-dimensional system, not only the governor will produce excessive compensation adjustment, but also the long-distance one-dimensional water conveying system and the governor system of the water turbine will consume a large amount of computing resources.

[0005] Therefore, there is an urgent need for a method and device capable of realizing one-dimensional and three-dimensional heterogeneous step coupling simulation calculation of multi-nozzle bucket-type hydraulic turbine. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application provides a one-dimensional and three-dimensional heterogeneous step coupling simulation method and device for multi-nozzle bucket-type hydraulic turbine.

[0007] The present application is realized by the following technical solutions:

[0008] In a first aspect, a one-dimensional and three-dimensional heterogeneous step coupling simulation method for multi-nozzle bucket-type hydraulic turbine is provided, comprising the following steps:

[0009] establishing a calculation model of a one-dimensional system and a three-dimensional system of the multi-nozzle bucket-type hydraulic turbine; wherein the calculation models of the two systems are coupled through a coupling surface; the one-dimensional system comprises a long water conveying system and a governor system of the water turbine; and the three-dimensional system comprises the multi-nozzle bucket-type hydraulic turbine;

[0010] determining the transient calculation time step of the one-dimensional system and the three-dimensional system;

[0011] calculating the initial state and the initial flow field of the one-dimensional system and the three-dimensional system;

[0012] determining whether the one-dimensional system and the three-dimensional system meet the heterogeneous step coupling discrimination relationship;

[0013] if the current time step meets the heterogeneous step coupling discrimination relationship, the one-dimensional and three-dimensional heterogeneous step coupling simulation calculation is performed; if not, the three-dimensional system simulation calculation is performed; until the calculation converges;

[0014] outputting and storing the calculation data of the one-dimensional and three-dimensional systems, completing the calculation at the current time; repeating the simulation calculation until the preset number of time steps is calculated.

[0015] In a possible implementation, the long water conveying system comprises: an upper regulating pool, a water conveying tunnel, a pressurized pipeline connected in sequence; and a tail water pool and a pressure regulating chamber connected to the water conveying tunnel.

[0016] Further, the coupling surface is determined according to the target of interest: if the three-dimensional flow state of the water bucket turbine including the water distribution ring is the target of interest, the coupling position is determined at the water distribution ring inlet of the water bucket turbine to construct a one-to-one coupling mode; if the three-dimensional flow state of the runner of the water bucket turbine is the target of interest, the coupling position is determined at the straight pipe section of the pressure pipeline to construct a one-to-many coupling mode.

[0017] In a possible implementation mode, the one-dimensional system transient calculation time step Δt 1D ≥ 0.001 s; and the three-dimensional system transient calculation time step Δt 3D ≤ 0.0005 s.

[0018] In a possible implementation mode, the method for calculating the initial state and initial flow field of the one-dimensional system and the three-dimensional system comprises the following steps.

[0019] For the one-dimensional system: the three-dimensional flow Q 3D and the three-dimensional pressure P 3D on the one-dimensional three-dimensional coupling surface are transmitted to the one-dimensional water conveying system as boundary conditions of the one-dimensional water conveying system, and the initial state calculation of the flow Q 1D and the pressure P 1D of the one-dimensional water conveying system is performed; and for the water turbine governor system, the runner torque M runner , the relative opening y relative and the power target value of the three-dimensional system are transmitted to the water turbine governor system through the data exchange program, and the initial state calculation of the water turbine governor system is performed.

[0020] For the three-dimensional system: after the one-dimensional system completes the initial state calculation, the one-dimensional pressure P 1D on the coupling surface is transmitted to the boundary of the three-dimensional system through the data exchange program; and the three-dimensional flow Q 3D and the pressure P 3D of the three-dimensional system before the transient calculation are calculated by the computational fluid dynamics.

[0021] In a possible implementation mode, the one-dimensional system and the three-dimensional system satisfy the formula of the asynchronous step coupling discriminant relationship as follows:

[0022] and k ≥ 1, n ∈ N + , k ∈ N +

[0023] wherein CS is the calculation step number of the three-dimensional system, n is the multiple, k is the asynchronous step coupling discriminant relationship, Δt 1D is the one-dimensional system transient calculation time step, Δt 3D is the three-dimensional system transient calculation time step, and N + represents a positive integer.

[0024] In a possible implementation, the method for one-dimensional three-dimensional heterogeneous time step coupling simulation calculation comprises the following steps.

[0025] acquiring one-dimensional pressure P of the coupling surface at the last coupling time 1D and needle valve action speed V output by the hydraulic turbine governor system PID performing computational fluid dynamics flow field transient calculation as the input of the boundary condition of the three-dimensional system, and calculating three-dimensional system including pressure and flow velocity at each grid point, and macro parameters such as hydraulic turbine torque and power, until residual calculation in the three-dimensional system converges;

[0026] for the one-dimensional water delivery system, transmitting three-dimensional flow Q 3D and pressure P 3D of the coupling surface through a data exchange program as the boundary condition of the one-dimensional water delivery system, and performing one-dimensional water delivery system transient flow calculation; and for the hydraulic turbine governor system, transmitting runner torque M runner and power relative value through the data exchange program as the input of the hydraulic turbine governor system, and performing governor system calculation;

[0027] outputting one-dimensional pressure P 1D of the coupling surface and needle valve action speed V PID of the governor system as the input of the computational fluid dynamics calculation of the three-dimensional system at the next coupling time.

[0028] In a possible implementation, the method for three-dimensional system simulation calculation comprises the following steps.

[0029] acquiring one-dimensional pressure P 1D of the coupling surface at the last coupling time as the boundary condition of the three-dimensional system, and performing computational fluid dynamics calculation until convergence.

[0030] In a second aspect, a one-dimensional three-dimensional heterogeneous time step coupling simulation device for a multi-nozzle bucket type hydraulic turbine is provided, comprising the following steps.

[0031] a model construction module configured to establish a calculation model of a one-dimensional system and a three-dimensional system of the multi-nozzle bucket type hydraulic turbine; wherein the calculation models of the two systems are coupled through a coupling surface; the one-dimensional system comprises a long water diversion water delivery system and a hydraulic turbine governor system; and the three-dimensional system comprises a multi-nozzle bucket type hydraulic turbine;

[0032] a time step determination module configured to determine a transient calculation time step of the one-dimensional system and the three-dimensional system;

[0033] an initialization module configured to calculate an initial state and an initial flow field of the one-dimensional system and the three-dimensional system;

[0034] The coupling determination module is configured to determine whether the one-dimensional system and the three-dimensional system meet a different time step coupling determination relationship.

[0035] The coupling calculation module is configured to perform one-dimensional and three-dimensional different time step coupling simulation calculation if the current time step meets the different time step coupling determination relationship, and perform three-dimensional system simulation calculation if the current time step does not meet the different time step coupling determination relationship, until the calculation converges.

[0036] The post-processing module is configured to output and store one-dimensional and three-dimensional system calculation data, complete current time calculation, and repeat simulation calculation until preset time step calculation is completed.

[0037] In a third aspect, an electronic device is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the one-dimensional and three-dimensional different time step coupling simulation method of the multi-nozzle bucket-type hydraulic turbine as described above when executing the program.

[0038] The beneficial effects of the present application are as follows:

[0039] 1. The present application realizes the one-dimensional and three-dimensional different time step coupling simulation method of the multi-nozzle bucket-type hydraulic turbine. The method uses small-scale time step calculation to simulate the dynamic change process of the bucket-type hydraulic turbine, which meets the precision requirement of transient calculation of the bucket-type hydraulic turbine and can also integrate the calculation efficiency of large-scale time step of the one-dimensional system.

[0040] 2. The one-dimensional and three-dimensional different time step coupling simulation method of the multi-nozzle bucket-type hydraulic turbine provided by the present application can accurately and efficiently simulate the power regulation process of the bucket-type hydraulic turbine in an actual scenario, improve the calculation precision and speed of the power regulation process of the multi-nozzle bucket-type hydraulic turbine, and obtain transition process information reflecting the real situation.

[0041] 3. The method can intuitively and clearly reflect the power regulation process of the multi-nozzle bucket-type hydraulic turbine, providing a more convenient way for related research. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The flowchart of the one-dimensional and three-dimensional different time step coupling simulation method of the multi-nozzle bucket-type hydraulic turbine related to the embodiments of the present application;

[0043] Figure 1 In the figure: 1 - upper regulation pool; 2 - diversion tunnel; 3 - pressure pipeline; 4 - bucket-type hydraulic turbine distribution ring pipe; 5 - tailrace pool; 6 - multi-nozzle bucket-type hydraulic turbine; 7 - surge tank.

[0044] Figure 2 The layout schematic diagram of the multi-nozzle bucket-type hydraulic turbine hydropower station related to the embodiments of the present application.

[0045] Figure 3A data exchange process schematic diagram of a one-dimensional three-dimensional heterogeneous time step coupling simulation method of a multi-nozzle bucket type hydraulic turbine involved in an embodiment of the present application.

[0046] Figure 4 A structural schematic diagram of a one-dimensional three-dimensional heterogeneous time step coupling simulation device of a multi-nozzle bucket type hydraulic turbine provided by the present application.

[0047] Figure 5 A structural schematic diagram of an electronic device provided by the present application. DETAILED DESCRIPTION

[0048] In order to facilitate those skilled in the art to understand and implement the present application, the present application will be further described below in combination with the drawings and specific embodiments, and the embodiments described herein are only used to illustrate and explain the present application, but the protection scope of the present application is not limited thereto.

[0049] Referring to Figure 1 , the present application provides a one-dimensional three-dimensional heterogeneous time step coupling simulation method of a multi-nozzle bucket type hydraulic turbine, comprising the following steps:

[0050] Step one, establishing a calculation model of a one-dimensional system and a three-dimensional system of a multi-nozzle bucket type hydraulic turbine; wherein the calculation models of the two systems are coupled through a coupling surface; the one-dimensional system comprises a long diversion water conveying system and a hydraulic turbine governor system; the three-dimensional system comprises a multi-nozzle bucket type hydraulic turbine.

[0051] In a possible implementation manner, in step one, referring to Figure 2 , the long diversion water conveying system comprises: an upper regulating pool, a diversion tunnel and a pressurized pipeline connected in sequence; and a surge chamber and a tail water pool arranged in the diversion tunnel.

[0052] In a possible implementation manner, the coupling surface is determined according to a target of interest; if the three-dimensional flow state of the bucket type hydraulic turbine including the water distribution ring pipe is taken as the target of interest, the coupling position is demarcated at the inlet of the water distribution ring pipe of the bucket type hydraulic turbine to construct a one-to-one coupling mode; if the three-dimensional flow state of the runner of the bucket type hydraulic turbine is taken as the target of interest, the coupling position is demarcated at the straight pipe section of the pressurized pipeline to construct a one-to-many coupling mode.

[0053] It should be noted that the one-to-one coupling mode is the coupling of the inlet section of the water distribution ring pipe of the bucket type hydraulic turbine in the one-dimensional system and the three-dimensional system; and the one-to-many coupling mode is the coupling of the straight pipe sections of the pressurized pipelines of the multiple nozzles in the one-dimensional system and the three-dimensional system.

[0054] Specifically, the present embodiment constructs a one-dimensional three-dimensional calculation model of a 6-nozzle bucket type hydraulic turbine, and the coupling surface is selected at the straight pipe section of the nozzle to construct a one-dimensional system to three-dimensional system straight pipe section coupling docking mode of the pressurized pipelines of the 6 nozzles.

[0055] Step two, determining the one-dimensional system and three-dimensional system transient calculation time step.

[0056] In one possible implementation, the one-dimensional system transient calculation time step Δt 1D ≥ 0.001 s; and the three-dimensional system transient calculation time step Δt 3D ≤ 0.0005 s.

[0057] It should be noted that the one-dimensional system transient calculation time step refers to the time interval between two adjacent calculation states in the one-dimensional numerical simulation process; and is used to control the time discretization in the one-dimensional system simulation calculation. The three-dimensional system transient calculation time step refers to the time interval between two adjacent flow states in the three-dimensional numerical simulation process; and is used to control the time discretization of the transient flow process in the three-dimensional system numerical simulation calculation.

[0058] It can be understood that the one-dimensional system time step Δt 1D needs to consider the requirements of the water delivery system and the water turbine governor system. For a long water delivery system, in order to avoid the attenuation and dispersion of water hammer waves in the pipeline caused by numerical interpolation of the characteristics line method, it is necessary to ensure that the number of segments of the one-dimensional three-dimensional coupling segment is at least 1 and the Courant number is 1. The one-dimensional three-dimensional coupling segment refers to the segment where the one-dimensional system and the three-dimensional system overlap each other, and the number of segments refers to the number of one-dimensional system and three-dimensional system segments for solving in the coupling segment. For the water turbine governor system, the requirements of water turbine inertia and control accuracy need to be considered. Through trial calculation, the one-dimensional system time step Δt 1D ≥ 0.001 s can meet the above requirements.

[0059] It can be understood that the three-dimensional system time step Δt 3D is determined according to the grid convergence coefficient (GCI) and the Courant number condition (CFL). The GCI should be less than 5%, and the CFL value range is 1-10. Through trial calculation, the three-dimensional system time step Δt 3D ≤ 0.0005 s can meet the above requirements.

[0060] Step three, calculating the initial state and initial flow field of the one-dimensional system and the three-dimensional system.

[0061] In one possible implementation, step three includes the following sub-steps:

[0062] 1. For the one-dimensional system: through the data exchange program, the three-dimensional flow Q 3D and the three-dimensional pressure P 3D on the one-dimensional three-dimensional coupling surface are taken as the boundary conditions of the one-dimensional water delivery system, and the initial state calculation of the flow Q 1D and the pressure P 1D of the one-dimensional water delivery system is performed; and for the water turbine governor system, the runner torque Mrunner , relative opening y relative and power target value, initial state calculation is performed on the water turbine governor system;

[0063] 2. For a three-dimensional system: after the one-dimensional system completes the initial state calculation, the one-dimensional pressure P 1D on the coupling surface is transmitted to the boundary of the three-dimensional system through a data exchange program; the three-dimensional system obtains the three-dimensional flow rate Q 3D and pressure P 3D before the start of transient calculation through computational fluid mechanics calculation.

[0064] Step four: determining whether the one-dimensional system and the three-dimensional system meet the asynchronous step coupling discriminant relationship.

[0065] In a possible implementation, the formula that the one-dimensional system and the three-dimensional system meet the asynchronous step coupling discriminant relationship is as follows:

[0066] and k≥1, n∈N + , k∈N +

[0067] wherein CS is the calculation step number of the three-dimensional system, n is the multiple, k is the asynchronous step coupling discriminant relationship, Δt 1D is the transient calculation time step of the one-dimensional system, Δt 3D is the transient calculation time step of the three-dimensional system, and N + represents a positive integer.

[0068] Specifically, in the embodiment, the asynchronous step coupling discriminant relationship is CS=k=10 or an integer multiple of 10; that is, when the calculation step number of the system is 10 steps or an integer multiple of 10, the asynchronous step coupling is performed.

[0069] The reason why it is necessary to determine whether the one-dimensional system and the three-dimensional system meet the asynchronous step coupling discriminant relationship is that when the calculation step number of the three-dimensional system meets the asynchronous step coupling discriminant relationship, the one-dimensional three-dimensional asynchronous step coupling simulation calculation is performed, otherwise the three-dimensional system simulation calculation is performed.

[0070] Step five: if the current time step meets the asynchronous step coupling discriminant relationship, the one-dimensional three-dimensional asynchronous step coupling simulation calculation is performed; if not, the three-dimensional system simulation calculation is performed; until the calculation converges.

[0071] In a possible implementation, the method of the one-dimensional three-dimensional asynchronous step coupling simulation calculation comprises:

[0072] acquiring the one-dimensional pressure P 1D on the coupling surface at the last coupling time and the needle valve action speed V PID output by the water turbine governor system.The three-dimensional system is calculated by using the input of the boundary condition of the three-dimensional system, and the pressure and flow velocity of each grid point in the three-dimensional system, and the macro parameters such as the torque and power of the water turbine are calculated until the residual error calculation in the three-dimensional system converges.

[0073] For the one-dimensional water delivery system, the three-dimensional flow Q 3D and pressure P 3D of the coupling surface are transmitted by a data exchange program (DEP) runner As the boundary condition of the one-dimensional water delivery system, the one-dimensional water delivery system transient flow calculation is carried out, and for the water turbine governor system, the runner torque M runner , power relative value is transmitted by DEP runner as the input of the water turbine governor system, and the governor system calculation is carried out.

[0074] The one-dimensional pressure P 1D of the coupling surface and the needle valve action speed V PID of the governor system are output as the input of the three-dimensional system (CFD) calculation at the next coupling time.

[0075] Further, the one-dimensional water delivery system transient flow calculation method is as follows:

[0076] (1) homogenize the three-dimensional flow Q 3D and pressure P 3D at the current time into one-dimensional flow Q 1D and pressure P 1D as the boundary condition input;

[0077] (2) the characteristic line method is used to calculate the flow and pressure of each hydraulic node of the water delivery system at the next time; and the calculated one-dimensional pressure P 1D of the coupling surface at the next time is output as the input of the three-dimensional system calculation of the fluid mechanics calculation at the next coupling time.

[0078] Further, the governor system calculation method is as follows:

[0079] (1) the macro parameters such as the torque and power of the water turbine calculated in the three-dimensional system are used as the input condition of the governor system;

[0080] (2) the incremental PID calculation, servo system calculation and speed and opening limit calculation are carried out in the governor system, and the calculated needle valve action speed V PID at the next time is output as the input of the three-dimensional system calculation of the fluid mechanics calculation at the next coupling time.

[0081] Referring to Figure 3 , Figure 3The middle reflects the process of data transmission between one-dimensional system and three-dimensional system in one-dimensional three-dimensional heterogeneous step coupling simulation calculation method. After the calculation time step of the three-dimensional system satisfies the heterogeneous step discrimination relation, the one-dimensional pressure P 1D and the needle valve action speed V of the governor system PID are input as boundary conditions. The three-dimensional system performs computational fluid dynamics calculation at the current time, and outputs the three-dimensional flow rate Q 3D , pressure P 3D and water turbine torque at the current time to the six coupling surfaces after the residual error converges, which are input as boundary conditions of the one-dimensional water delivery system and the governor system. Then, the characteristic line method is used to calculate the flow rate and pressure at each hydraulic node in the one-dimensional water delivery system, and the one-dimensional pressure P 1D at the coupling surface at the next time is output as the input of the computational fluid dynamics calculation of the three-dimensional system at the next coupling time. Finally, the incremental PID calculation, servo system calculation and speed and opening limit calculation are performed in the governor system, and the needle valve action speed V PID at the next time is output as the input of the computational fluid dynamics calculation of the three-dimensional system at the next coupling time.

[0082] In a possible implementation manner, the method for simulating the three-dimensional system comprises the following steps.

[0083] The one-dimensional pressure P 1D at the coupling surface at the last coupling time is obtained as the boundary condition of the three-dimensional system, and the computational fluid dynamics calculation is performed to obtain the pressure and flow rate of each grid point in the three-dimensional system, as well as the water turbine torque, power and other macroscopic parameters until the residual error calculation converges.

[0084] Step six, output and store the calculation data of the one-dimensional three-dimensional system, and complete the calculation at the current time. Repeat steps five and six until the calculation of the preset time step is completed.

[0085] In a possible implementation manner, in step six, the calculation data comprises:

[0086] In the one-dimensional water delivery system, the flow rate and pressure data of each hydraulic node, the flow rate flowing into and out of the surge chamber and the water level of the surge chamber; in the governor system, the calculation data of the incremental PID, the needle valve opening and the needle valve action speed;

[0087] In the three-dimensional system, the pressure and flow rate of each grid point, as well as the water turbine torque, power and other macroscopic parameters.

[0088] The following describes the one-dimensional and three-dimensional asynchronous time-step coupling simulation device for multi-nozzle bucket turbines provided by the present invention. The one-dimensional and three-dimensional asynchronous time-step coupling simulation device for multi-nozzle bucket turbines described below can be referred to in correspondence with the one-dimensional and three-dimensional asynchronous time-step coupling simulation method for multi-nozzle bucket turbines described above.

[0089] Figure 4 This is a schematic diagram of the structure of the one-dimensional and three-dimensional asynchronous time-step coupling simulation device for a multi-nozzle bucket turbine provided in an embodiment of the present invention, as shown below. Figure 4 As shown, it includes: a model building module 41, a time step determination module 42, an initialization module 43, a coupling determination module 44, a coupling calculation module 45, and a post-processing module 46, wherein:

[0090] Model building module 41 is used to establish computational models of a one-dimensional system and a three-dimensional system of a multi-nozzle bucket turbine; wherein, the computational models of the two systems are coupled through a coupling surface; the one-dimensional system includes a long water intake and conveyance system and a turbine governor system; the three-dimensional system includes a multi-nozzle bucket turbine;

[0091] The time step determination module 42 is used to determine the time step for transient calculation of one-dimensional and three-dimensional systems.

[0092] Initialization module 43 is used to calculate the initial state and initial flow field of the one-dimensional and three-dimensional systems;

[0093] The coupling determination module 44 is used to determine whether the one-dimensional system and the three-dimensional system conform to the time-step coupling discrimination relationship;

[0094] The coupling calculation module 45 is used to: perform one-dimensional and three-dimensional time-step coupling simulation calculations if the current time step satisfies the time-step coupling discrimination relationship; otherwise, perform three-dimensional system simulation calculations until the calculation converges.

[0095] The post-processing module 46 is used to output and store the calculation data of the one-dimensional and three-dimensional system, complete the calculation at the current moment, and repeat the simulation calculation until the preset number of time steps are completed.

[0096] Figure 5 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 5 As shown, the electronic device may include a processor 510, a communication interface 520, a memory 530, and a communication bus 540. The processor 510, communication interface 520, and memory 530 communicate with each other via the communication bus 540. The processor 510 can call logic instructions from the memory 530 to execute a one-dimensional / three-dimensional asynchronous time-step coupling simulation method for multi-nozzle bucket turbines.

[0097] Furthermore, the logic instructions in the memory 830 described above can be implemented in the form of software functional units and sold or used as independent products, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that make contributions to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0098] The device embodiments described above are only schematic, wherein the units illustrated as separate components can or can not be physically separate, and the components illustrated as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment. Those skilled in the art can understand and implement without creative labor.

[0099] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be implemented by means of software and the necessary general hardware platform, and of course can also be implemented by hardware. Based on such understanding, the technical solutions described above essentially or the parts that make contributions to the prior art can be embodied in the form of a software product. The computer software product can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0100] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A one-dimensional three-dimensional heterogeneous time step coupling simulation method for a multi-jet bucket-type hydraulic turbine, characterized in that, The method comprises the following steps: A one-dimensional system and a three-dimensional system of the multi-nozzle Pelton turbine are established, and the calculation models of the two systems are coupled through a coupling surface; the one-dimensional system comprises a long diversion water delivery system and a turbine governor system; the three-dimensional system comprises the multi-nozzle Pelton turbine; and the one-dimensional system and the three-dimensional system satisfy the formula of the heterogeneous step coupling discrimination relationship as follows: , and , , where CS is the number of calculation steps of the three-dimensional system, n is a multiple, k is the asynchronous coupling discrimination relationship ， is the time step of transient calculation of the one-dimensional system, is the time step of transient calculation of the three-dimensional system, denotes a positive integer; The time step of transient calculation of the one-dimensional system and the three-dimensional system is determined; The initial state and the initial flow field of the one-dimensional system and the three-dimensional system are calculated; It is determined whether the one-dimensional system and the three-dimensional system satisfy the heterogeneous step coupling discrimination relationship; If the current time step satisfies the heterogeneous step coupling discrimination relationship, one-dimensional and three-dimensional heterogeneous step coupling simulation calculation is performed; if not, three-dimensional system simulation calculation is performed; until the calculation converges; the one-dimensional and three-dimensional heterogeneous step coupling simulation calculation method comprises the following steps: Obtain the one-dimensional pressure at the coupling surface at the previous coupling moment. The needle valve operating speed output by the turbine governor system The input of boundary conditions for the three-dimensional system is used for computational fluid dynamics transient flow field calculations, obtaining macroscopic parameters in the three-dimensional system, including pressure and velocity at each grid point, as well as turbine torque and power, until the residual calculation in the three-dimensional system converges. For the one-dimensional water conveyance system, the three-dimensional flow rate at the coupling surface is transmitted through a data exchange program. and pressure As boundary conditions for a one-dimensional water conveyance system, transient flow calculations are performed for the system; and for the turbine governor system, the turbine torque is transmitted via a data exchange program. The relative power value is used as the input to the turbine governor system for governor system calculations; the one-dimensional pressure at the output coupling surface is used. and the needle valve operating speed of the speed controller system , which serves as the input for the computational fluid dynamics calculation of the three-dimensional system at the next coupling moment; The one-dimensional and three-dimensional system calculation data are output and stored, and the current time calculation is completed; the simulation calculation is repeated until the preset time step calculation is completed.

2. The one-dimensional three-dimensional heterogeneous step coupling simulation method of the multi-nozzle bucket-type hydraulic turbine according to claim 1, characterized in that, The long diversion water delivery system comprises an upper regulating pool, a diversion tunnel, a pressurized pipeline connected in sequence, and a tail water pool and a pressure regulating chamber connected to the diversion tunnel.

3. The one-dimensional three-dimensional heterogeneous step coupling simulation method of the multi-nozzle bucket-type hydraulic turbine according to claim 2, characterized in that, The coupling surface is determined according to the target of interest: if the three-dimensional flow state of the Pelton turbine including the water distribution ring is taken as the target of interest, the coupling position is determined at the inlet of the water distribution ring of the Pelton turbine to construct a one-to-one coupling mode; if the three-dimensional flow state of the runner of the Pelton turbine is taken as the target of interest, the coupling position is determined at the straight pipe section of the pressurized pipeline to construct a one-to-many coupling mode.

4. The one-dimensional three-dimensional heterogeneous step coupling simulation method of the multi-nozzle bucket-type hydraulic turbine according to claim 1, characterized in that, the one-dimensional system transient calculation time step ≥ 0.001 s; the three-dimensional system transient calculation time step ≤ 0.0005 s.

5. The one-dimensional three-dimensional heterogeneous step coupling simulation method of the multi-nozzle bucket-type hydraulic turbine according to claim 1, characterized in that, The method for calculating the initial state and the initial flow field of the one-dimensional system and the three-dimensional system comprises the following steps: For a one-dimensional system: the three-dimensional flow on the one-dimensional and three-dimensional coupled surface is transferred through a data exchange program. and three-dimensional pressure As boundary conditions for a one-dimensional water conveyance system, the flow rate of the one-dimensional water conveyance system... and pressure Initial state calculations are performed; and for the turbine governor system, the runner torque of the three-dimensional system is transmitted through a data exchange program. Relative opening Based on the target power value, the initial state calculation of the turbine governor system is performed. For the three-dimensional system: after the one-dimensional system has finished the initialization state calculation, the one-dimensional pressure on the coupling surface is passed to the three-dimensional system through a data exchange program Boundary to the three-dimensional system; the three-dimensional system obtains the three-dimensional flow rate before the start of the transient calculation through computational fluid dynamics calculation And pressure .

6. The one-dimensional three-dimensional heterogeneous step coupled simulation method of the multi-jet bucket turbine according to claim 1, wherein, The three-dimensional system simulation calculation method comprises the following steps: acquiring one-dimensional pressure of the coupling surface at the previous coupling time As boundary conditions for the three-dimensional system, computational fluid dynamics calculations are performed until convergence.

7. A one-dimensional three-dimensional heterogeneous time step coupling simulation device for a multi-jet bucket type hydraulic turbine, characterized in that, The one-dimensional and three-dimensional heterogeneous step coupling simulation method for the multi-nozzle Pelton turbine of claim 1 comprises the following steps: A model construction module is configured to establish a one-dimensional system and a three-dimensional system of the multi-nozzle Pelton turbine; the calculation models of the two systems are coupled through a coupling surface; the one-dimensional system comprises a long diversion water delivery system and a turbine governor system; the three-dimensional system comprises the multi-nozzle Pelton turbine; A time step determination module is configured to determine the time step of transient calculation of the one-dimensional system and the three-dimensional system; An initialization module is configured to calculate the initial state and the initial flow field of the one-dimensional system and the three-dimensional system; A coupling determination module is configured to determine whether the one-dimensional system and the three-dimensional system satisfy the heterogeneous step coupling discrimination relationship; A coupling calculation module is configured to perform one-dimensional and three-dimensional heterogeneous step coupling simulation calculation if the current time step satisfies the heterogeneous step coupling discrimination relationship; if not, perform three-dimensional system simulation calculation; until the calculation converges; A post-processing module is configured to output and store the one-dimensional and three-dimensional system calculation data, complete the current time calculation, and repeat the simulation calculation until the preset time step calculation is completed.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the one-dimensional and three-dimensional heterogeneous step coupling simulation method of the multi-nozzle Pelton turbine according to any one of claims 1 to 6.

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