Steam seal pressure control method for steam turbine

Abstract

The invention belongs to the technical field of steam turbine control, and particularly relates to a steam turbine steam seal pressure control method which comprises the following steps: determining a steam seal pressure range and a target value according to steam seal pressure historical data; a steam seal pressure sensor is adopted to obtain steam seal pressure values, and the steam seal pressure values are averaged to obtain a steam seal pressure average value; subtracting the average value of the steam seal pressure from a target value and then taking an absolute value to obtain a deviation value; the steam seal pressure is controlled by adopting an incremental PID controller; pID parameters are optimized based on an index-trigonometric function algorithm; the increment PID controller after parameter optimization outputs the opening degree of the steam seal pressure regulating valve, the steam seal pressure regulating valve is controlled in real time, and then steam seal pressure control is achieved. According to the method, the gland sealing pressure measurement error can be reduced; the parameter of the incremental PID controller is optimized by adopting an index-trigonometric function algorithm, and the method has the advantages of high identification precision, short response time and good system robustness.

Description

Technical Field

[0001] This invention belongs to the field of steam turbine control technology, and specifically relates to a method for controlling the steam seal pressure of a steam turbine. Background Technology

[0002] Maintaining stable steam seal pressure is crucial for the safety and economy of a steam turbine during operation. Improper control of the steam seal pressure can lead to dangerous steam leaks and reduce turbine efficiency. Traditional steam seal pressure control methods suffer from slow response and low control precision, easily resulting in large fluctuations in steam seal pressure, which negatively impacts turbine operating efficiency and stability. Therefore, rapid and accurate control of the steam turbine's steam seal pressure is essential. Summary of the Invention

[0003] To address the issues of slow response and low control accuracy in existing steam turbine sealing pressure control methods, a new steam turbine sealing pressure control method is proposed.

[0004] The first aspect of this application provides a method for controlling the steam seal pressure of a steam turbine, comprising:

[0005] The steam turbine sealing pressure deviation value is obtained and input into the incremental PID controller to obtain the sealing pressure control signal. The opening of the sealing pressure regulating valve is adjusted based on the sealing pressure control signal.

[0006] The incremental PID controller is an incremental PID controller with optimized parameters based on the exponential-trigonometric function algorithm.

[0007] A second aspect of this application provides a computer-readable storage device storing a computer program that, when executed by a processor, implements the steps of a steam turbine sealing pressure control method as described in the first aspect of this application.

[0008] A third aspect of this application provides a steam turbine sealing pressure control device, including a storage device, a processor, and a computer program stored in the storage device and executable on the processor. The processor executes the computer program to implement the steps of a steam turbine sealing pressure control method as described in the first aspect of this application.

[0009] The fourth aspect of this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the steam turbine sealing pressure control method described in the first aspect of this application.

[0010] The beneficial effects of this invention are:

[0011] 1. The present invention uses a first steam seal pressure sensor and a second steam seal pressure sensor to monitor the steam seal pressure simultaneously, which can reduce the measurement error of the steam seal pressure;

[0012] 2. The incremental PID controller parameters are optimized using an exponential-trigonometric function algorithm, which has the advantages of high identification accuracy, fast response time, and good system robustness;

[0013] 3. Through real-time calculations, the steam seal pressure can be controlled quickly and accurately. Attached Figure Description

[0014] Figure 1 A flowchart illustrating a method for controlling steam seal pressure in a steam turbine, as described in a specific embodiment of this application;

[0015] Figure 2 This is a schematic diagram of the PID control principle in a specific embodiment of this application. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0017] Specific Implementation Method 1: A method for controlling the steam seal pressure of a steam turbine, comprising:

[0018] The steam turbine sealing pressure deviation value is obtained and input into the incremental PID controller to obtain the sealing pressure control signal. The opening of the sealing pressure regulating valve is adjusted based on the sealing pressure control signal.

[0019] The incremental PID controller is an incremental PID controller with optimized parameters based on the exponential-trigonometric function algorithm.

[0020] Further, the turbine steam seal pressure deviation value is obtained, including:

[0021] The target value SP for the steam turbine sealing pressure is determined based on historical data of the steam turbine sealing pressure.

[0022] The pressure value of the first steam seal at time t is obtained using the first steam seal pressure sensor. The pressure value of the second steam seal at time t is obtained through the second steam seal pressure sensor. ;

[0023] The first steam seal pressure value at time t Second steam seal pressure value Take the average value to obtain the average value of the steam seal pressure at time t. , ;

[0024] The average steam seal pressure at time t The absolute value of the difference between the deviation and the target value SP is used to obtain the steam seal pressure deviation at time t. , .

[0025] Furthermore, the method for obtaining the steam seal pressure control signal by inputting the steam seal pressure deviation value to the incremental PID controller is as follows:

[0026] ,in, The steam seal pressure control signal is given at time t. This is the steam seal pressure control signal at time t-1. The value of the steam seal pressure deviation at time t-1. The value of the steam seal pressure deviation at time t-2. This is the proportionality coefficient. The integral coefficient is... is the differential coefficient.

[0027] Furthermore, the incremental PID controller is an incremental PID controller with optimized parameters based on the exponential-trigonometric function algorithm;

[0028] The parameters optimized by the incremental PID controller include the proportional gain. Integral coefficient and differential coefficients .

[0029] As a preferred method, the incremental PID controller parameters are optimized based on the exponential-trigonometric function algorithm, including:

[0030] S1: Initialize algorithm parameters, setting the population size K, variable dimension D, and maximum number of iterations N;

[0031] S2: Set the iteration count n=0 and randomly initialize the population positions;

[0032] S3: Calculate the fitness value for each individual in the population. Determine the fitness value Is it less than the minimum fitness value? If so, the fitness value will be... As the minimum fitness value ; set the minimum fitness value The corresponding individual is taken as the optimal solution;

[0033] S4: Determine if n > N. If yes, input the parameter corresponding to the optimal solution as the optimal parameter into the incremental PID controller. Otherwise, set n = n + 1 and update the position of the individual in the population, then go to S3.

[0034] Furthermore, an initial population is randomly generated, and the position of each individual in the initial population is determined by the following formula:

[0035] ,in, For the i-th individual in the initial population, the j-th dimension is the solution. Let j be the upper bound of the j-th dimension. Let the j-th dimension be the lower bound. for Random value, , .

[0036] Furthermore, the fitness value for each individual in the population is calculated, and the parameters corresponding to each individual in the population are updated based on the fitness value, including:

[0037] fitness value , The deviation value of the steam seal pressure at time t;

[0038] Furthermore, update the location of individuals in the population, including:

[0039] Calculate behavior judgment parameters ,when Then the n+1th iteration belongs to the exploration phase, when Then the (n+1)th iteration belongs to the development phase;

[0040] ,in, Represents the square root function. As the first scalar parameter, It is the second scalar parameter;

[0041] ;

[0042] ;

[0043] During the exploration phase, the individual positions are updated sequentially according to the first and second exploration phases:

[0044] During the first phase of exploration, the individual position is updated using the following formula:

[0045] ;

[0046] in, This represents the j-th dimension solution for the i-th individual at iteration number n+1. This represents the j-th dimension solution for the i-th individual at iteration number n. For the j-th dimension, As the first weighting coefficient,

[0047] ;

[0048] In the second phase of exploration, the individual position is updated using the following formula:

[0049] ;

[0050] in, This is the second weighting coefficient. ;

[0051] During the development phase, the individual positions are updated sequentially according to the first and second development phases:

[0052] In the first phase of development, the individual position is updated using the following formula:

[0053] ;

[0054] in, This is the third weighting coefficient. , A random number within the interval [0,1];

[0055] In the second phase of development, the individual position is updated using the following formula:

[0056] ,in, .

[0057] Specific Implementation Method Two: A computer-readable storage device storing a computer program, which, when executed by a processor, implements the steps of a steam turbine steam seal pressure control method as described in Specific Implementation Method One.

[0058] Specific Embodiment 3: A steam turbine steam seal pressure control device includes a storage device, a processor, and a computer program stored in the storage device and executable on the processor. The processor executes the computer program to implement the steps of the steam turbine steam seal pressure control method as described in Specific Embodiment 1.

[0059] Specific Implementation Method Four: A computer program product, including a computer program, which, when executed by a processor, implements the steps of a steam turbine steam seal pressure control method as described in Specific Implementation Method One.

[0060] Example:

[0061] There is an existing steam turbine unit, and its steam seal pressure needs to be controlled.

[0062] Based on historical data of steam seal pressure, the pressure range of the steam sealer was determined to be 0.0–600 kPa, with a target value SP of 200 kPa. Two steam seal pressure sensors were used to acquire the steam seal pressure value at time t. The Pa is 175.8 kPa. The pressure is 175.6 kPa; the steam seal pressure at time t is... and The average value of the steam seal pressure is obtained by taking the average value. ;

[0063] ;

[0064] The average steam seal pressure at time t The deviation value is obtained by taking the absolute value of the difference between the deviation and the target value SP. ;

[0065] ;

[0066] The steam seal pressure is controlled using an incremental PID controller according to the following rules:

[0067]

[0068]

[0069] in, The control signal at time t, This is the control signal at time t-1. The value of the steam seal pressure deviation at time t-1. The value of the steam seal pressure deviation at time t-2. This is the proportionality coefficient. The integral coefficient is... is the differential coefficient.

[0070] Optimize PID parameters based on the Exponential-Trigonometric (ETO) algorithm: , and ;

[0071] Initialize the algorithm parameters: population size K is 30, variable dimension D is 3, and maximum number of iterations N is 50;

[0072] Randomly initialize the population: Randomly generate the initial population, and the position of each individual is determined by the following formula;

[0073]

[0074] in, For the i-th individual in the initial population, the j-th dimension is the solution. Let j be the upper bound of the j-th dimension. Let the j-th dimension be the lower bound. for Random value, , .

[0075] like , and These represent the incremental PID parameters of the first individual in the initial population. , and ;

[0076] Calculate the fitness value;

[0077] ,in, This is the deviation value.

[0078] For the proportionality coefficient First optimization fitness Second optimization fitness , To optimize step size; if Then update ;like Then update , The fitness value of parameter P; for the integral coefficient and differential coefficients Repeat the above steps until the maximum number of iterations is reached;

[0079] Select the group with the smallest fitness value from the first K groups. , and As the optimal solution;

[0080] The following formula can be used to determine whether the next action is in the exploration or development phase;

[0081] ;

[0082] when During the exploratory phase, when For the development stage;

[0083] Update individual location;

[0084] During the first phase of exploration, the individual position is updated using the following formula:

[0085] ;

[0086] ;

[0087] ;

[0088] ;

[0089] in, It is the optimal solution in the j-th dimension. This is the j-th dimension solution for the i-th individual at iteration number k+1. For the i-th individual in dimension j at iteration number k, for A random value, k is the current iteration number, and K is the maximum iteration number.

[0090] In the second phase of exploration, the individual position is updated using the following formula:

[0091] ,

[0092] ,

[0093] In the first phase of development, the individual position is updated using the following formula:

[0094] ,

[0095] ,

[0096] In the second phase of development, the individual position is updated using the following formula:

[0097] ,

[0098] ,

[0099] Determine if the maximum number of iterations has been reached. If the maximum number of iterations has been reached, then use the obtained optimal solution as the optimal scaling factor. Integral coefficient and differential coefficients Output to the incremental PID controller; otherwise, recalculate the fitness value.

[0100] The optimized incremental PID controller outputs the opening degree of the steam seal pressure regulating valve, thereby controlling the steam seal pressure in real time.

[0101] While specific embodiments of this application have been described herein with reference to them, it should be understood that these embodiments are merely examples of the principles and applications of this application. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of this application as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A method of controlling the pressure of a steam seal of a steam turbine, characterized by, The method comprises the following steps: The turbine seal pressure deviation value is obtained, and the turbine seal pressure deviation value is input into an incremental PID controller to obtain a turbine seal pressure control signal, and the turbine seal pressure control signal is used to adjust the opening of a turbine seal pressure regulating valve; The incremental PID controller is an incremental PID controller with optimized parameters based on an exponential-trigonometric function algorithm.

2. A method of controlling the pressure of a steam seal of a steam turbine according to claim 1, characterized in that: The turbine seal pressure deviation value is obtained, and the turbine seal pressure deviation value is input into an incremental PID controller to obtain a turbine seal pressure control signal, and the turbine seal pressure control signal is used to adjust the opening of a turbine seal pressure regulating valve; The turbine seal pressure target value SP is determined according to historical data of the turbine seal pressure. acquire the first seal pressure value at the moment through the first seal pressure sensor acquire the first seal pressure value at the moment through the first seal pressure sensor acquire the second seal pressure value at the moment through the second seal pressure sensor acquire the second seal pressure value at the moment through the second seal pressure sensor ; Will the first seal pressure value and the second seal pressure value take the average value, get will the seal pressure average value , ; Will Instant steam seal pressure average value Difference with target value SP, absolute value, get Instant steam seal pressure deviation value , .

3. The turbine seal pressure control method according to claim 2, characterized in that: The turbine seal pressure deviation value is input into an incremental PID controller to obtain a turbine seal pressure control signal, and the turbine seal pressure control signal is used to adjust the opening of a turbine seal pressure regulating valve; ； wherein, is the instant steam seal pressure control signal, is the -1 instant steam seal pressure control signal, is the -1 instant steam seal pressure deviation value, is the -2 instant steam seal pressure deviation value, is a proportional coefficient, is an integral coefficient, is a derivative coefficient.

4. The turbine seal pressure control method according to claim 3, characterized in that: The parameters of the incremental PID controller are optimized based on an exponential-trigonometric function algorithm, and the method comprises the following steps: S1: Initialize the algorithm parameters, set the population size K, the variable dimension D, and the maximum number of iterations N; S2: Let the iteration number n = 0, and randomly initialize the population position; S3: calculating the fitness value corresponding to each individual of the population , judging whether the fitness value is less than the minimum fitness value , if yes, taking the fitness value as the minimum fitness value ; taking the individual corresponding to the minimum fitness value as the optimal solution ; if no, going to S4 ; if yes, going to S5 ; if no, going to S6 S4: Determine whether n > N. If yes, the optimal parameters corresponding to the optimal solution are input into the incremental PID controller; otherwise, let n = n + 1 and update the population individual position, and return to S3.

5. The turbine seal pressure control method according to claim 4, characterized in that: The initial population is randomly generated, and the position of each individual in the initial population is determined by the following formula: ； wherein, is the jth dimension of the ith individual in the initial population, is the jth dimension upper bound, is the jth dimension lower bound, is the jth dimension of the ith individual in the initial population, is a random value, , .

6. The turbine seal pressure control method according to claim 5, characterized in that: Fitness value , For Instant steam seal pressure deviation value.

7. The turbine seal pressure control method according to claim 6, characterized in that: The population individual position is updated, and the method comprises the following steps: Computing a behavior judgment parameter When then the n+1 iteration behavior belongs to the exploration phase, when then the n+1 iteration behavior belongs to the exploitation phase; wherein, denotes a square root function, is a first scalar parameter, is a second scalar parameter; ； ； In the exploration stage, the individual position is updated in the first exploration stage and the second exploration stage in turn: In the first exploration stage, the individual position is updated according to the following formula: ； wherein, is the jthdimensional solution of the ithindividual at iteration number n+1, is the jthdimensional solution of the ithindividual at iteration number n, is the jthdimensional optimal solution, is the first weight coefficient, ； In the second exploration stage, the individual position is updated according to the following formula: ； wherein is a second weight coefficient, ; In the development stage, the individual position is updated in the first development stage and the second development stage in turn: In the first development stage, the individual position is updated according to the following formula: ； wherein is a third weight coefficient, , is a random number in the interval [0, 1]; In the second development stage, the individual position is updated according to the following formula: wherein .

8. A storage device readable by a computer, the storage device storing a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the turbine seal pressure control method according to any one of claims 1 to 7.

9. A turbine gland seal pressure control apparatus comprising a storage device, a processor, and a computer program stored in the storage device and operable on the processor, wherein, The processor executes the computer program to realize the steps of the turbine seal pressure control method according to any one of claims 1 to 7.

10. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the turbine seal pressure control method according to any one of claims 1 to 7.

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