Method for determining closing law of turbine guide vane, terminal device and storage medium

Abstract

The present invention discloses a method for determining the closing law of a water turbine guide vane, a terminal device, and a storage medium. The method includes obtaining the acting force generated by the hydrodynamic torque in the guide vane control system; obtaining the loss coefficient of the hydraulic servo device under static water; determining the guide vane opening under dynamic water according to the acting force generated by the hydrodynamic torque and the loss coefficient of the hydraulic servo device; determining a fitness function according to the guide vane opening under dynamic water and the guide vane closing law required by the water turbine regulation guarantee design, and using a genetic algorithm to determine the closing law of the water turbine guide vane under the action of the hydrodynamic torque. The present invention aims at making the closing law of the guide vane under dynamic water consistent with the design value of the regulation guarantee. By optimizing and solving the closing law of the guide vane under static water through a genetic algorithm, it can quickly obtain the adjustment value of the guide vane closing under static water, ensure that the closing law of the guide vane under dynamic water coincides with the design value, guarantee the safety of the water turbine unit during the load rejection transient process, and the method has the advantages of strong operability and high precision.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic turbines, and particularly relates to a method for determining the closing law of the guide vane of a hydraulic turbine, a terminal device and a storage medium, especially a method for determining the closing law of the guide vane of a hydraulic turbine under the action of dynamic water torque, a terminal device and a storage medium. Background Art

[0002] When a hydropower unit fails, it is necessary to quickly close the guide vane to prevent the unit from running away and major safety accidents. The most ideal closing law of the guide vane of a hydraulic turbine needs to be determined through detailed regulation guarantee calculation. If the guide vane closes too slowly, it is easy to cause the speed of the hydro-generator unit to be too high, resulting in over-speed or runaway of the unit. If the guide vane closes too quickly, it will cause too high water hammer in the water conveyance channel, resulting in pipe burst and damage to the structural components of the hydraulic turbine.

[0003] The closing speed of the guide vane is mainly controlled by adjusting the maximum stroke of the main distributor valve of the governor system. For the safety of the on-site unit operation, in the actual work of a hydropower plant, professionals must adjust the closing speed of the guide vane under static conditions (when there is no water in the unit's stop channel). The guide vane of a hydraulic turbine is designed with a certain eccentricity, and the guide vane will bear a certain dynamic water torque during the actual operation of the unit. Therefore, there are obvious differences between the closing law of the guide vane in actual dynamic water and that under static conditions. If the closing law of the guide vane is adjusted according to the designed regulation guarantee requirements under static conditions, there will be a certain difference between the actual closing law of the guide vane during the actual operation of the unit and the design requirements, and there is a risk of over-speed and too high water hammer pressure during the actual load rejection transient process of the unit. Summary of the Invention

[0004] The present invention provides a method for determining the closing law of the guide vane of a hydraulic turbine, a terminal device and a storage medium, thus solving the technical problems of over-speed and too high water hammer pressure existing in the existing guide vane closing process.

[0005] The first aspect of the present invention discloses a method for determining the closing law of the guide vane of a hydraulic turbine under the action of dynamic water torque, including:

[0006] Obtaining the acting force generated by the dynamic water torque in the guide vane control system;

[0007] Obtaining the loss coefficient of the hydraulic servo device under static water;

[0008] Determining the guide vane opening under dynamic water according to the acting force generated by the dynamic water torque and the loss coefficient of the hydraulic servo device, and the guide vane opening under dynamic water is a function of the guide vane opening under static water;

[0009] Determining a fitness function according to the guide vane opening under dynamic water and the guide vane closing law required by the regulation guarantee design of the hydraulic turbine, and determining the closing law of the guide vane of the hydraulic turbine under the action of dynamic water torque by using a genetic algorithm according to the fitness function.

[0010] Preferably, obtaining the acting force generated by the hydrodynamic torque in the guide vane control system specifically includes:

[0011] Determining the hydrodynamic torque on the guide vane according to the guide vane opening;

[0012] Determining the acting force generated by the hydrodynamic torque in the guide vane control system according to the hydrodynamic torque on the guide vane.

[0013] Preferably, determining the hydrodynamic torque on the guide vane according to the guide vane opening specifically includes:

[0014] Using the first formula to determine the hydrodynamic torque on the guide vane, and the first formula is:

[0015]

[0016] In the formula, M h is the hydrodynamic torque on the guide vane, H is the working head of the water turbine, D1 is the runner diameter of the water turbine, Q 11 is the unit flow rate of the water turbine, C M is the hydrodynamic torque coefficient of the guide vane, and the hydrodynamic torque coefficient of the guide vane is a function of the guide vane opening.

[0017] Preferably, determining the acting force generated by the hydrodynamic torque in the guide vane control system according to the hydrodynamic torque on the guide vane specifically includes:

[0018] Using the second formula to determine the acting force generated by the hydrodynamic torque in the guide vane control system, and the second formula is:

[0019]

[0020] In the formula, R h is the acting force generated by the hydrodynamic torque in the guide vane control system, M h is the hydrodynamic torque on the guide vane, Z0 is the number of guide vanes, D c is the diameter at the connection between the guide vane connecting rod and the control ring, D ce is the diameter at the connection between the servomotor ear handle and the control ring, L P is the straight-line distance from the guide vane connecting rod to the guide vane rotation center, β is the angle between the control ring tangent at the connection between the guide vane connecting rod and the control ring, and γ is the angle between the guide vane connecting rod and the rocker arm.

[0021] Preferably, obtaining the loss coefficient of the hydraulic servo device under static water specifically includes:

[0022] Using the third formula to determine the loss coefficient of the hydraulic servo device under static water, and the third formula is:

[0023]

[0024] In the formula, A pis the loss coefficient of the hydraulic servo device, P0 is the pressure of the speed regulation system, γ is the angle between the guide vane connecting rod and the rocker arm, g is the acceleration due to gravity, and Y 静 is the guide vane opening under static water, and is the closing speed of the guide vane under static water.

[0025] Preferably, according to the acting force generated by the dynamic water torque and the loss coefficient of the hydraulic servo device, the guide vane opening under dynamic water is determined, which specifically includes:

[0026] Using the fourth formula to determine the guide vane opening under dynamic water, and the fourth formula is:

[0027]

[0028] In the formula, Y 动 is the guide vane opening under dynamic water action, m is the mass of the guide vane servomotor piston and the components moving together with it, F is the area of the servomotor piston, P0 is the pressure of the speed regulation system, A p is the loss coefficient of the hydraulic servo device, γ is the angle between the guide vane connecting rod and the rocker arm, g is the acceleration due to gravity, and R h is the acting force generated by the dynamic water torque in the guide vane control system.

[0029] Preferably, according to the guide vane opening under dynamic water and the guide vane closing law required by the turbine regulation guarantee design, a fitness function is determined, which specifically includes:

[0030] Using the fifth formula to determine the fitness function, and the fifth formula is:

[0031]

[0032] In the formula, Fit is the fitness function, Y 动 is the guide vane opening under dynamic water action, Y S is the guide vane closing law required by the turbine regulation guarantee design, and t is the time.

[0033] Preferably, according to the fitness function, a genetic algorithm is used to determine the guide vane closing law of the turbine under the action of dynamic water torque, which specifically includes:

[0034] Let the population variable be the guide vane opening under static water;

[0035] Substitute the first-generation population into the fitness function;

[0036] Calculate the value of the fitness function substituting the first-generation population, and determine the guide vane closing law of the turbine under the action of dynamic water torque according to the value.

[0037] The second aspect of the present invention discloses a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above method are implemented.

[0038] The third aspect of the present invention discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above method.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1) Through precise calculation and analysis, the present invention obtains the operation equation of the guide vane control system under dynamic water with the static water guide vane opening as a variable. This equation reflects the relationship between the guide vane opening change process under dynamic water and the guide vane closing law under static water, providing an accurate means for adjusting and optimizing the guide vane closing law.

[0041] 2) Aiming at making the guide vane closing law under dynamic water consistent with the regulated guarantee design value, the present invention optimizes and solves the guide vane closing law under static water through a genetic algorithm, and can quickly and conveniently obtain the adjustment value of the guide vane closing under static water, ensuring that the guide vane closing law under dynamic water coincides with the design value, guaranteeing the safety of the water turbine unit during load rejection transient process. Moreover, this method has the advantages of strong operability and high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Attached Figure 1 is a schematic flowchart of the method for determining the guide vane closing law of a water turbine under the action of dynamic water torque according to the present invention;

[0043] Attached Figure 2 is a detailed flowchart of the method for determining the guide vane closing law of a water turbine under the action of dynamic water torque according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0044] The following will further elaborate on the technical solutions of the present invention in detail in combination with the drawings and specific implementation cases. It should be understood that the following embodiments are only for exemplarily illustrating and explaining the present invention, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0045] The content of the present invention relates to the on-site adjustment and calculation method of the guide vane closing law during the transient process of a water turbine, specifically a method for determining the guide vane closing law of a water turbine under the action of dynamic water torque. It mainly solves the motion equations of the guide vane and its control system under the action of dynamic water torque, and takes the consistency between the guide vane closing law under dynamic water and the regulated guarantee design value as the objective function, and uses a genetic algorithm to solve the optimal adjustment value of the guide vane closing under static water. Its flowchart is asFigure 1 and Figure 2 As shown in, it includes:

[0046] Step 1. Obtain the acting force generated by the hydrodynamic torque in the guide vane control system, specifically including:

[0047] Step 1.1. Determine the hydrodynamic torque on the guide vane according to the guide vane opening.

[0048] According to the hydroturbine model test, obtain the variation process C of the guide vane hydrodynamic torque coefficient with the guide vane opening M = f(Y).

[0049] According to C M = f(Y), calculate the variation process M of the hydrodynamic torque on the guide vane with the guide vane opening h = f(Y) as shown in Equation (1):

[0050]

[0051] In the formula, M h is the hydrodynamic torque on the guide vane, H is the working head of the hydroturbine, D1 is the runner diameter of the hydroturbine, Q 11 is the unit flow rate of the hydroturbine, which can be obtained from the comprehensive characteristic curve of the hydroturbine model, C M is the guide vane hydrodynamic torque coefficient, and the guide vane hydrodynamic torque coefficient is a function of the guide vane opening Y.

[0052] Step 1.2. Determine the acting force generated by the hydrodynamic torque in the guide vane control system according to the hydrodynamic torque on the guide vane.

[0053] According to M h Calculate the acting force R generated by the hydrodynamic torque in the guide vane control system h = f(Y) as shown in Formula (2):

[0054]

[0055] In the formula, R h is the acting force generated by the hydrodynamic torque in the guide vane control system, M h is the hydrodynamic torque on the guide vane, Z0 is the number of guide vanes, D c is the diameter at the connection of the guide vane connecting rod and the control ring, D ce is the diameter at the connection of the servomotor ear handle and the control ring, L P is the straight-line distance from the guide vane connecting rod to the guide vane rotation center, β is the angle between the control ring tangent at the connection of the guide vane connecting rod and the control ring, and γ is the angle between the guide vane connecting rod and the rocker arm. Among them, both β and γ are functions of the guide vane opening.

[0056] Step 2. Obtain the loss coefficient of the hydrostatic hydraulic servo device.

[0057] List the motion equation of the hydraulic servo device of the speed control system under static conditions, that is, the motion equation of the lower guide vane control system under static water is shown in Formula (3):

[0058]

[0059] In the formula, m is the mass of the guide vane relay piston and the parts moving together, Y 静 is the guide vane opening under static water, t is time, is the closing speed of the guide vane under static water, that is, the closing law of the guide vane under static water, F is the area of the relay piston, P0 is the pressure of the speed control system, A p is the loss coefficient of the hydraulic servo device, γ is the angle between the guide vane connecting rod and the crank arm, and g is the acceleration due to gravity.

[0060] Considering that when the displacement stroke of the main pilot valve of the governor is constant, the guide vane under static water basically runs at a constant speed, that is The relationship between the loss coefficient (A p ) of the hydraulic servo device and the closing speed of the guide vane under static water is shown in Formula (4):

[0061]

[0062] In the formula, A p is the loss coefficient of the hydraulic servo device, P0 is the pressure of the speed control system, γ is the angle between the guide vane connecting rod and the crank arm, g is the acceleration due to gravity, Y 静 is the guide vane opening under static water, is the closing speed of the guide vane under static water.

[0063] Step 3: Determine the guide vane opening under dynamic water according to the acting force generated by the dynamic water torque and the loss coefficient of the hydraulic servo device. The guide vane opening under dynamic water is a function of the guide vane opening under static water.

[0064] The motion equation of the guide vane control system under dynamic water is shown in Formula (5):

[0065]

[0066] In the formula, Y 动 is the guide vane opening under the action of dynamic water, m is the mass of the guide vane relay piston and the parts moving together, F is the area of the relay piston, P0 is the pressure of the speed control system, A p is the loss coefficient of the hydraulic servo device, γ is the angle between the guide vane connecting rod and the crank arm, g is the acceleration due to gravity, R h is the acting force generated by the dynamic water torque in the guide vane control system.

[0067] Substituting Formula (2) and Formula (4) into Formula (5), the relationship between the guide vane opening under dynamic water and the guide vane opening under static water shown in Formula (6) can be obtained:

[0068]

[0069] Y 动 The fourth-order Runge-Kutta method is used to solve for Y 动 = f(R h , P0, m, F, Y 静 , t) and obtained.

[0070] Step 4: Determine the fitness function according to the guide vane opening under dynamic water and the guide vane closing law required by the turbine regulation guarantee design. According to the fitness function, use the genetic algorithm to determine the guide vane closing law of the turbine under the action of dynamic water torque.

[0071] Step 4.1: Determine the fitness function according to the guide vane opening under dynamic water and the guide vane closing law required by the turbine regulation guarantee design. The fitness function is shown in Formula (7):

[0072]

[0073] In the formula, Fit is the fitness function, Y 动 is the guide vane opening under the action of dynamic water, Y S is the guide vane closing law required by the turbine regulation guarantee design, t is time, and T is the total time period.

[0074] Step 4.2: According to the fitness function, use the genetic algorithm to determine the guide vane closing law of the turbine under the action of dynamic water torque.

[0075] Let the population variable be Y 静 , and use the genetic algorithm to establish an optimization model for the guide vane closing law. Calculate the optimal solution Y OP静 , and this value is the optimal guide vane closing law adjusted under static water, specifically including:

[0076] ① Initialize the population, and randomly generate the initial population within the range of Y s ± 50%Y s ;

[0077] ② Take the initialized population as the first-generation population of the genetic algorithm;

[0078] ③ Substitute the first-generation population into the fitness function to calculate the fitness;

[0079] ④ Calculate the fitness to obtain Fit, and judge that if Fit is less than the set precision value, the best solution calculation ends, otherwise it enters the new population selection;

[0080] ⑤ Sample selection. First, calculate the sum of the fitness values of all individuals in the existing population Σfit (i = 1, 2, …, M); secondly, calculate the relative fitness of each individual fit / Σfit, which is the probability of each individual being inherited into the next generation population. Each probability value forms a region, and the sum of all probability values is 1. Finally, generate a random number between 0 and 1, and determine the number of times each individual is selected according to which probability region the random number appears in.

[0081] ⑥ Crossover operation. First, randomly pair the population, and secondly, randomly set the crossover point position; finally, exchange some genes between the paired chromosomes.

[0082] ⑦ Mutation operation. The basic bit mutation method is used for mutation operation. The specific operation process is as follows: First, determine the gene mutation positions of each individual; then, according to a certain probability, reverse the original gene value at the mutation point.

[0083] ⑧ For population Y 静(G) After performing a round of selection, crossover, and mutation operations, a new generation of population Y can be obtained. 静(G+1) .

[0084] ⑨ Generate a new generation of population Y 静(G+1) Then bring it into step ④ for calculation.

[0085] The present invention optimizes the adjustment method of the guide vane closing law by calculating the change process of the guide vane opening under the hydrodynamic torque. The core idea is to obtain the relationship between the change process of the guide vane opening under dynamic water and the change process of the guide vane opening under static water through force analysis and numerical calculation, and use an optimization algorithm for optimization and solution. The method of the present invention is an adjustment method for the guide vane closing law that accurately considers the action of the hydrodynamic torque, so that the guide vane closing law in the actual operation of the hydropower unit is consistent with the requirements of the regulation guarantee, ensuring the safety of the load rejection transient process of the hydropower unit, and the method should have the advantages of strong operability and high precision.

[0086] The second aspect of the content of the present invention discloses a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above method are implemented.

[0087] The third aspect of the content of the present invention discloses a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the above method are implemented.

[0088] The above are only the preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above in its preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above, or modify it into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for determining the closing law of a water turbine guide vane, characterized in that, including: obtaining the acting force generated by the hydrodynamic torque in the guide vane control system; obtaining the loss coefficient of the hydraulic servo device under static water; determining the guide vane opening under dynamic water according to the acting force generated by the hydrodynamic torque and the loss coefficient of the hydraulic servo device, where the guide vane opening under dynamic water is a function of the guide vane opening under static water; determining a fitness function according to the guide vane opening under dynamic water and the guide vane closing law required by the water turbine regulation guarantee design, and determining the water turbine guide vane closing law under the action of the hydrodynamic torque by using a genetic algorithm according to the fitness function; the guide vane opening under dynamic water is a function of the guide vane opening under static water, specifically as follows: where Y 动 is the guide vane opening under the action of dynamic water, t is the time, m is the mass of the guide vane servomotor piston and the components moving together with it, F is the area of the servomotor piston, P0 is the pressure of the governing system, Y 静 is the guide vane opening under static water, and R h is the acting force generated by the dynamic water torque in the guide vane control system.

2. The method according to claim 1, characterized in that, the obtaining the acting force generated by the hydrodynamic torque in the guide vane control system specifically includes: determining the hydrodynamic torque received by the guide vane according to the guide vane opening; determining the acting force generated by the hydrodynamic torque in the guide vane control system according to the hydrodynamic torque received by the guide vane.

3. The method according to claim 2, characterized in that, determining the hydrodynamic torque received by the guide vane according to the guide vane opening specifically includes: using a first formula to determine the hydrodynamic torque received by the guide vane, and the first formula is: Where, M h is the hydrodynamic torque on the guide vane, H is the working head of the turbine, D1 is the runner diameter of the turbine, Q 11 is the unit flow rate of the turbine, C M is the hydrodynamic torque coefficient of the guide vane, and the hydrodynamic torque coefficient of the guide vane is a function of the guide vane opening.

4. The method according to claim 2, characterized in that, determining the acting force generated by the hydrodynamic torque in the guide vane control system according to the hydrodynamic torque received by the guide vane specifically includes: using a second formula to determine the acting force generated by the hydrodynamic torque in the guide vane control system, and the second formula is: Wherein, R h is the acting force generated by the hydrodynamic torque in the guide vane control system, M h is the hydrodynamic torque received by the guide vane, Z0 is the number of guide vanes, D c is the diameter at the connection between the guide vane connecting rod and the control ring, D ce is the diameter at the connection between the servomotor ear handle and the control ring, L P is the straight-line distance from the guide vane connecting rod to the guide vane rotation center, β is the angle between the control ring tangent at the connection between the guide vane connecting rod and the control ring, and γ is the included angle between the guide vane connecting rod and the rocker arm.

5. The method according to any one of claims 1-4, characterized in that, determining the fitness function according to the guide vane opening under dynamic water and the guide vane closing law required by the water turbine regulation guarantee design specifically includes: using a fifth formula to determine the fitness function, and the fifth formula is: where Fit is the fitness function, Y 动 is the guide vane opening under the action of dynamic water, and Y S is the guide vane closing law required by the design of the water turbine regulation guarantee, and t is the time.

6. The method according to claim 5, characterized in that, determining the water turbine guide vane closing law under the action of the hydrodynamic torque by using a genetic algorithm according to the fitness function specifically includes: letting the population variable be the guide vane opening under static water; substituting the first-generation population into the fitness function; calculating the value of the fitness function into which the first-generation population is substituted, and determining the water turbine guide vane closing law under the action of the hydrodynamic torque according to the value.

7. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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