Closed-loop control method and device for deep peak-shaving steam turbine based on relative stress margin

Abstract

The present application proposes a closed-loop control method and device for a deep peak-shaving steam turbine based on relative stress margin, the method comprising: obtaining the first equivalent stress of the high-temperature key components of the deep peak-shaving steam turbine, and obtaining the absolute value of the first equivalent stress, wherein the first equivalent stress has positive and negative properties; obtaining the material allowable limit stress of the high-temperature key components; obtaining the absolute value of the first equivalent stress and the difference between the material allowable limit stress, and determining the relative stress margin of the high-temperature key components based on the difference and the absolute value of the first equivalent stress; and performing closed-loop control on the speed and load of the steam turbine under target operating conditions based on the relative stress margin of the high-temperature key components. In the present application, based on the relative stress margin, closed-loop control is performed on the speed and load of the steam turbine under target operating conditions, so as to achieve long-life flexible operation of the deep peak-shaving steam turbine, and thereby achieve the set operating target of the steam turbine as much as possible.

Description

Technical Field

[0001] The present application relates to the technical field of steam turbines, and in particular to a closed-loop control method and device for a deep peak-shaving steam turbine based on relative stress margin. Background Art

[0002] In the context of building a new power system with new energy as the main body, renewable energy such as wind power and solar energy has developed rapidly. In view of the intermittent, random and volatile problems of renewable energy power generation, it is required that the power station steam turbine be deeply peak-shifted and flexibly operated and transformed into emergency guarantee and flexible adjustment power supply to provide a bottom-line guarantee for power supply. The deep peak-shifting, rapid start-up and rapid load change of the steam turbine lead to increased thermal stress and shortened life of the high-temperature components of the steam turbine, affecting the service life and safety of the steam turbine. Summary of the invention

[0003] The embodiments of the present application provide a closed-loop control method and device for a deep peak-shaving steam turbine based on relative stress margin.

[0004] The first embodiment of the present application proposes a closed-loop control method for a deep peak-shaving steam turbine based on relative stress margin, comprising:

[0005] Obtaining a first equivalent stress of a high-temperature key component of a deep peak-shaving steam turbine, and obtaining an absolute value of the first equivalent stress, wherein the first equivalent stress has positive and negative properties;

[0006] Obtaining the material allowable limit stress of the high-temperature key component;

[0007] Obtaining a difference between an absolute value of the first equivalent stress and an allowable limit stress of the material, and determining a relative stress margin of the high-temperature key component according to the difference and the absolute value of the first equivalent stress;

[0008] According to the relative stress margin of the high-temperature key components, the speed and load of the steam turbine under the target operating condition are controlled in a closed loop.

[0009] The second embodiment of the present application proposes a closed-loop control device for a deep peak-shaving steam turbine based on relative stress margin, comprising:

[0010] A first acquisition module is used to acquire a first equivalent stress of a high-temperature key component of a deep peak-shaving steam turbine, and to acquire an absolute value of the first equivalent stress, wherein the first equivalent stress has positive and negative properties;

[0011] A second acquisition module is used to obtain the allowable limit stress of the material of the high-temperature key component;

[0012] A third acquisition module is used to obtain the difference between the absolute value of the first equivalent stress and the allowable limit stress of the material, and determine the relative stress margin of the high-temperature key component according to the difference and the absolute value of the first equivalent stress;

[0013] The control module is used to perform closed-loop control on the speed and load of the steam turbine under target operating conditions according to the relative stress margin of the high-temperature key components.

[0014] The third aspect of the present application provides an electronic device, including:

[0015] one or more processors;

[0016] a memory for storing instructions executable by the processor;

[0017] Among them, the processor is configured to execute the instructions to implement the method proposed in the embodiment of the first aspect of the present application.

[0018] The fourth aspect embodiment of the present application proposes a non-temporary computer-readable storage medium. When the instructions in the storage medium are executed by the processor of an electronic device, the electronic device can execute the method proposed in the first aspect embodiment of the present application.

[0019] The fifth aspect embodiment of the present application proposes a computer program product, including a computer program, which implements the method proposed in the first aspect embodiment of the present application when executed by a processor in a communication device.

[0020] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:

[0021] In order to achieve long life and flexible operation of the steam turbine, the relative stress margin of high-temperature key components can be monitored, and the change rate of the closed-loop control parameters can be determined based on such monitoring data, so as to adjust the closed-loop control parameters according to the change rate. That is, during the start-up process, shutdown process or load change process of the steam turbine, the turbine speed before grid connection and after disconnection, as well as the turbine load after grid connection and before disconnection are closed-loop controlled, which can not only reasonably extend the life of the steam turbine, but also improve the flexibility of the steam turbine, so as to achieve long-life and flexible operation of the deep peak-shaving steam turbine, and thus make the long-life and flexible operation of the deep peak-shaving steam turbine reach the set goals as much as possible, such as the crack initiation calendar life reaching 40 years, the cumulative loss of the crack initiation life being only 0.75 (75%) of the total life loss, 10,000 starts, 20,000 rapid load changes, 250 starts per year, 500 rapid load changes per year, and the minimum safe and stable operating load for deep peak-shaving is 20% of the rated power.

[0022] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0024] Figure 1 A schematic flow chart of a closed-loop control method based on relative stress margin for a deep peak-shaving steam turbine provided in an embodiment of the present application;

[0025] Figure 2 A schematic flow chart of another closed-loop control method based on relative stress margin for a deep peak-shaving steam turbine provided in an embodiment of the present application;

[0026] Figure 3 A schematic flow chart of another closed-loop control method based on relative stress margin for a deep peak-shaving steam turbine provided in an embodiment of the present application;

[0027] Figure 4 A schematic flow chart of another closed-loop control method based on relative stress margin for a deep peak-shaving steam turbine provided in an embodiment of the present application;

[0028] Figure 4a A schematic diagram of a process for determining the average volume temperature of a high-temperature rotor provided in an embodiment of the present application;

[0029] Figure 4b A schematic diagram of a process for determining the center temperature of a high-temperature rotor provided in an embodiment of the present application;

[0030] Figure 5 A schematic flow chart of another closed-loop control method based on relative stress margin for a deep peak-shaving steam turbine provided in an embodiment of the present application;

[0031] Figure 6 A schematic structural diagram of a closed-loop control device based on relative stress margin for a deep peak-shaving steam turbine provided in an embodiment of the present application;

[0032] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0033] Figure 8 A schematic diagram of the structure of another electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0036] It should be understood that, although the terms first, second, third, etc. may be used to describe various information in the embodiments of the present application, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the embodiments of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein may be interpreted as "at..." or "when..." or "in response to determination".

[0037] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0038] It should be noted that the deep peak-shaving steam turbine based on relative stress margin closed-loop control method provided in any embodiment of the present application can be executed alone, or can be executed in combination with possible implementation methods in other embodiments, or can be executed in combination with any technical solution in the relevant technology.

[0039] The following describes the closed-loop control method, device, electronic device and storage medium based on relative stress margin of the deep peak-shaving steam turbine disclosed in the present invention in conjunction with the reference drawings.

[0040] Figure 1 A schematic flow chart of a closed-loop control method based on relative stress margin for a deep peak-shaving steam turbine provided in an embodiment of the present application. Figure 1 As shown, the method includes but is not limited to the following steps:

[0041] S101, obtaining a first equivalent stress of a high-temperature key component of a deep peak-shaving steam turbine, and obtaining an absolute value of the first equivalent stress, wherein the first equivalent stress has positive and negative properties.

[0042] In an embodiment of the present application, the high-temperature key components of the deep peak-shaving steam turbine include a main steam valve housing, a regulating valve housing, a high-temperature rotor and a high-temperature cylinder. The main steam valve housing of the steam turbine includes an ultra-high-pressure main steam valve housing, a high-pressure main steam valve housing and a medium-pressure main steam valve housing. The regulating valve housing of the steam turbine includes an ultra-high-pressure regulating valve housing, a high-pressure regulating steam valve housing and a medium-pressure regulating valve housing. The high-temperature rotor of the steam turbine includes an ultra-high-pressure rotor, a high-pressure rotor and a medium-pressure rotor. The high-temperature outer cylinder of the steam turbine includes an ultra-high-pressure outer cylinder, a high-pressure outer cylinder and a medium-pressure outer cylinder.

[0043] In some implementations, high temperature critical components of the steam turbine are associated with the reheat type of the steam turbine.

[0044] In the embodiment of the present application, the reheat type of the steam turbine is determined. Optionally, the reheat type of the steam turbine can be determined based on the equipment information of the steam turbine. The reheat type can include double reheat, single reheat and no reheat. Further, according to the reheat type of the steam turbine, the high temperature key components of the steam turbine are determined.

[0045] Optionally, if the steam turbine is a secondary reheat steam turbine, the high-temperature key components of the steam turbine include the main steam valve housings of the ultra-high pressure cylinder, the high pressure cylinder and the medium pressure cylinder, the regulating valve housings, the high-temperature rotor and the high-temperature outer cylinder.

[0046] Optionally, if the steam turbine is a single reheat steam turbine, the high-temperature key components of the steam turbine include the main steam valve housings of the high-pressure cylinder and the medium-pressure cylinder, the regulating valve housings, the high-temperature rotor and the high-temperature outer cylinder.

[0047] Optionally, if the steam turbine is a non-reheat steam turbine, the high-temperature key components of the steam turbine include a main steam valve housing of the high-pressure cylinder, a regulating valve housing, a high-temperature rotor and a high-temperature outer cylinder.

[0048] In some embodiments, the first equivalent stress of the high temperature key component has positive and negative properties, that is, the high temperature key component has an equivalent stress with positive and negative signs. Optionally, the composite stress of the high temperature key component in each direction is obtained, and the first equivalent stress of the high temperature key component is determined according to the composite stress of the high temperature key component in each direction. Optionally, the composite stress of the high temperature key component in each direction includes radial composite stress, transverse composite stress and axial composite stress.

[0049] Optionally, the composite stress of the high-temperature key component in each direction can be obtained by synthesizing the thermal stress and mechanical stress of the high-temperature key component in each direction.

[0050] S102, obtaining the allowable limit stress of the material of the high-temperature key components.

[0051] The operating temperature of the high temperature key component is obtained, and the allowable limit stress of the material of the high temperature key component is determined according to the operating temperature. Optionally, the creep limit temperature of the material of the high temperature key component is obtained, and further, the allowable limit stress of the material of the high temperature key component is determined according to the relationship between the operating temperature and the creep limit temperature of the material.

[0052] Optionally, the creep limit temperature of carbon steel material of high-temperature key components of steam turbine is 350°C, the creep limit temperature of alloy steel material of high-temperature key components of steam turbine is 420°C, the creep limit temperature of heat-resistant steel material of high-temperature key components of steam turbine is 480°C, and the creep limit temperature of nickel-based alloy material of high-temperature key components of steam turbine is 650°C.

[0053] If the operating temperature of the high-temperature key component is greater than or equal to the material creep limit temperature, the material yield limit and The creep rupture time of high temperature key components is t r =The minimum value is determined from the material endurance strength of 5000h, which is used as the allowable limit stress of the material for high-temperature key components.

[0054] If the operating temperature of the high-temperature critical component is lower than the material creep limit temperature, the material yield limit of the high-temperature critical component is determined as the allowable limit stress of the material of the high-temperature critical component.

[0055] S103, obtaining a difference between an absolute value of a first equivalent stress and an allowable limit stress of a material, and determining a relative stress margin of a high-temperature key component according to the difference and the absolute value of the first equivalent stress.

[0056] Optionally, the relative stress margin R of the high temperature key components of the steam turbine sjk (τ), R s is the relative stress margin, where subscript j represents the working environment of key components, V represents ultra-high pressure, H represents high pressure, and I represents medium pressure. Subscript k represents the name of the turbine component, S represents the main steam valve housing, A represents the regulating valve housing, R represents the rotor, and C represents the outer cylinder. sjk The calculation formula of (τ) is:

[0057]

[0058] Among them, σ pujk (τ) represents the material allowable limit stress of high temperature key components, σ ejk (τ) represents the first equivalent stress with positive and negative signs of high temperature key components.

[0059] S104, performing closed-loop control on the speed and load of the steam turbine under target operating conditions according to the relative stress margin of the high-temperature key components.

[0060] The relative stress margin of each high-temperature key component is compared, and the minimum value is determined as the minimum relative stress margin of the turbine. Based on the minimum relative stress margin, the speed and load under the target operating conditions are controlled.

[0061] Optionally, the speed change rate of the speed and the load change rate of the load are determined according to the minimum relative stress margin, and further, the speed of the steam turbine under the target operating condition is controlled according to the speed change rate, and the load under the target operating condition is controlled according to the load change rate. That is, according to the speed change rate of the steam turbine, the speed of the steam turbine before the grid connection during the startup process and the speed after the shutdown process are disconnected are closed-loop controlled. According to the load change rate of the steam turbine, the load after the grid connection during the startup process and the load before the shutdown process are closed-loop controlled.

[0062] In the embodiment of the present application, in order to achieve long life and flexible operation of the steam turbine, the relative stress margin of high-temperature key components can be monitored, and based on such monitoring data, the change rate of the operating parameters can be determined to adjust the operating parameters according to the change rate, that is, during the turbine startup process, shutdown process or load change process, the turbine speed before grid connection and after decoupling, as well as the turbine load after grid connection and before decoupling are closed-loop controlled, which can not only reasonably extend the life of the steam turbine, but also improve the flexibility of the steam turbine, so as to achieve long-life and flexible operation of the deep peak-shaving steam turbine, and thus make the long-life and flexible operation of the deep peak-shaving steam turbine can reach the set goals as much as possible, such as the crack initiation calendar life reaching 40 years, the cumulative loss of the crack initiation life is only 0.75 (75%) of the total life loss, 10,000 starts, 20,000 rapid load changes, 250 starts per year, 500 rapid load changes per year, and the minimum safe and stable operating load for deep peak-shaving is 20% of the rated power.

[0063] Figure 2 A schematic flow chart of another closed-loop control method for a deep peak-shaving steam turbine based on relative stress margin provided in an embodiment of the present application. Figure 2 As shown, the method includes but is not limited to the following steps:

[0064] S201, obtain the thermal stress and mechanical stress of the high-temperature key components of the deep peak-shaving steam turbine in all directions.

[0065] In some embodiments, the temperature difference of the high temperature key component is determined, and the tangential thermal stress and axial thermal stress of the high temperature key component are determined according to the material physical properties of the high temperature key component and the temperature difference, wherein the radial thermal stress of the high temperature key component is zero.

[0066] In some embodiments, the material physical properties of the high temperature critical component may include, but are not limited to: the material linear expansion coefficient, the material elastic modulus, and the material Poisson's ratio of the high temperature critical component.

[0067] Optionally, if the high temperature key component is a high temperature rotor, the process of determining the temperature difference of the high temperature rotor includes:

[0068] The volume average temperature of the high temperature rotor, the outer surface temperature of the high temperature rotor and the center temperature of the high temperature rotor are obtained, and the temperature difference of the high temperature rotor is determined according to the volume average temperature of the high temperature rotor, the outer surface temperature of the high temperature rotor and the center temperature of the high temperature rotor.

[0069] Optionally, the rotor outer diameter of the high-temperature rotor is obtained, and the volume average temperature of the high-temperature rotor is determined based on the rotor outer diameter and the previous volume average temperature of the high-temperature rotor, as well as the first-class inertia link time constant used to calculate the volume average temperature of the high-temperature rotor, and based on the outer surface temperature of the high-temperature rotor and the first-class inertia link time constant set.

[0070] Optionally, the rotor outer diameter of the high-temperature rotor is obtained, and the high-temperature rotor center temperature is determined based on the rotor outer diameter and the previous rotor center temperature of the high-temperature rotor, as well as the second-type inertia link time constant used to calculate the rotor center temperature of the high-temperature rotor, and based on the outer surface temperature of the high-temperature rotor and the set of second-type inertia link time constants.

[0071] In some implementations, the surface temperature difference between the volume average temperature of the high temperature rotor and the outer surface temperature of the high temperature rotor is obtained, and the center temperature difference between the volume average temperature of the high temperature rotor and the center temperature is obtained. Further, the temperature difference of the high temperature rotor is determined according to the surface temperature difference and the center temperature difference. Optionally, the maximum value is determined from the surface temperature difference and the center temperature difference as the temperature difference of the high temperature rotor; optionally, the surface temperature difference and the center temperature difference are weighted to obtain the temperature difference of the high temperature rotor.

[0072] Optionally, the metal temperature of the measuring point at the set depth of the inner cylinder wall thickness is determined, and the metal temperature of the measuring point at the set depth of the inner cylinder wall thickness is determined as the outer surface temperature of the high-temperature rotor. For example, the outer surface temperature of the high-temperature rotor can be the metal temperature of the measuring point at the depth of 90% of the inner cylinder wall thickness.

[0073] Optionally, the high temperature key component is not a high temperature rotor, for example, the high temperature key component is a main steam valve housing, a regulating valve housing and a high temperature outer cylinder, etc. The process of determining the temperature difference of the high temperature key component includes: detecting the metal temperature of the measuring point of the high temperature key component at different wall thickness depths, and determining the temperature difference of the high temperature key component according to the metal temperature of the measuring point at different wall thickness depths.

[0074] In some implementations, the high-temperature key component is a high-temperature rotor, and the online monitoring value of the operating speed and the rated operating speed of the steam turbine are obtained, and the finite element calculated values ​​of the centrifugal stress in each direction of the outer surface of the high-temperature rotor at the rated operating speed of the steam turbine are obtained. For any direction, the centrifugal stress of the high-temperature rotor in any direction is determined based on the online monitoring value of the operating speed and the rated operating speed, as well as the finite element calculated values ​​of the centrifugal stress in any direction.

[0075] In some implementations, the high temperature key component is a non-high temperature rotor, the pressure on the inner surface of the cylinder wall of the high temperature key component is obtained, the radius on the inner surface of the cylinder wall of the high temperature key component and the radius on the outer surface are obtained, and further, the radial mechanical stress and the tangential mechanical stress of the high temperature key component are determined according to the pressure on the inner surface of the cylinder wall, the radius on the inner surface of the cylinder wall and the radius on the outer surface, wherein the axial mechanical stress is 0.

[0076] S202, determining a first equivalent stress of the high-temperature key component according to the thermal stress and mechanical stress of the high-temperature key component in various directions, wherein the first equivalent stress has positive and negative properties.

[0077] In the embodiment of the present application, the composite stress of the high temperature key component in each direction is determined according to the thermal stress in each direction and the mechanical stress in each direction. Optionally, the radial thermal stress and the radial mechanical stress of the high temperature key component are added to obtain the radial composite stress of the high temperature key component. Optionally, the tangential thermal stress and the tangential mechanical stress of the high temperature key component are added to obtain the tangential composite stress of the high temperature key component. Optionally, the axial thermal stress and the axial mechanical stress of the high temperature key component are added to obtain the axial composite stress of the high temperature key component.

[0078] Further, according to the composite stress of the high-temperature critical component in each direction, the first equivalent stress of the high-temperature critical component with positive and negative signs is determined. In some implementations, the maximum composite stress and the minimum composite stress are determined from the composite stress in each direction, and the second equivalent stress of the high-temperature critical component is determined according to the composite stress of the high-temperature critical component in each direction, wherein the second equivalent stress is a positive value. Optionally, the difference of the composite stress in each direction is determined, and the second equivalent stress of the high-temperature critical component is determined according to the difference of the composite stress in each direction. Further, according to the second equivalent stress, the maximum composite stress and the minimum composite stress, the first equivalent stress of the high-temperature critical component is determined.

[0079] S203, obtaining the allowable limit stress of the material of the high-temperature key components.

[0080] S204, obtaining the difference between the absolute value of the first equivalent stress and the allowable limit stress of the material, and determining the relative stress margin of the high-temperature key component according to the difference and the absolute value of the first equivalent stress.

[0081] For a detailed introduction to steps S203 to S204, please refer to the implementation methods in the various embodiments of the present application, which will not be repeated here.

[0082] S205, performing closed-loop control on the speed and load of the steam turbine under target operating conditions according to the relative stress margin of the high-temperature key components.

[0083] The relative stress margin of each high-temperature key component is compared, and the minimum value is determined as the minimum relative stress margin of the turbine. Based on the minimum relative stress margin, the speed and load under the target operating conditions are controlled.

[0084] Optionally, according to the target interval range where the minimum relative stress margin is located, a mapping strategy for the target interval range is further determined, and the minimum relative stress margin is mapped according to the mapping strategy to obtain a correction coefficient corresponding to the minimum relative stress margin.

[0085] Further, the speed change rate of the steam turbine is determined according to the correction coefficient and the speed change rate setting value, and the speed of the steam turbine is closed-loop controlled according to the speed change rate. Optionally, the product of the correction coefficient and the speed change rate setting value is obtained as the speed change rate of the speed.

[0086] Further, the load change rate of the steam turbine is determined according to the correction coefficient and the load change rate setting value, and the load of the steam turbine is closed-loop controlled according to the load change rate. Optionally, the product of the correction coefficient and the load change rate setting value is obtained as the speed change rate of the load.

[0087] In some implementations, a speed change rate range is determined, a start or shutdown type of the steam turbine is obtained, and a speed change rate set value is determined from the speed change rate range according to the start or shutdown type.

[0088] Optionally, the speed change rate range is determined according to the rated value of the speed of the steam turbine. For example, the speed change rate range of the steam turbine can be 4 to 16%n0[(r / min) / min]. The set value of the speed change rate n s , n s =4~16%n0[(r / min) / min], where n0 is the rated speed of the turbine (r / min).

[0089] Optionally, if the steam turbine is a slow start or shutdown type, the lower limit value of the speed change rate range is determined to be the speed change rate setting value; optionally, if the steam turbine is a normal start or shutdown type, the middle value of the speed change rate range is determined to be the speed change rate setting value; optionally, if the steam turbine is a fast start or shutdown type, the upper limit value of the speed change rate range is determined to be the speed change rate setting value.

[0090] In some implementations, a load change rate range is determined, a load change state of the steam turbine is acquired, and a load change rate set value is determined from the load change rate range according to the load change state.

[0091] Optionally, the load change rate range is determined according to the maximum continuous power TMCR of the steam turbine. For example, the load change rate range of the steam turbine can be 3-5% TMCR (MW / min). The set value N of the load change rate s , N s =3~5%TMCR(MW / min), where TMCR is the maximum continuous power of the turbine (MW).

[0092] Optionally, if the steam turbine increases or decreases load below the 30% TMCR load range, the lower limit of the load change rate range is determined to be the load change rate setting value; optionally, if the steam turbine increases or decreases load within the 30% to 50% TMCR load range, the middle value of the load change rate range is determined to be the load change rate setting value; optionally, if the steam turbine increases or decreases load within the 50% to 100% TMCR load range, the upper limit of the load change rate range is determined to be the load change rate setting value.

[0093] Optionally, if the minimum stress safety multiple is within the emergency shutdown range, the steam turbine is controlled to perform an emergency shutdown operation after a set time.

[0094] In the embodiments of the present application, in order to achieve long life and flexible operation of the steam turbine, the relative stress margin of high-temperature key components can be monitored, and based on such monitoring data, the change rate of the operating parameters can be determined to adjust the operating parameters according to the change rate. That is, during the startup process, shutdown process or load change process of the steam turbine, the turbine speed before grid connection and after decoupling, as well as the turbine load after grid connection and before decoupling are closed-loop controlled, which can not only reasonably extend the life of the steam turbine, but also improve the flexibility of the steam turbine, so as to achieve long life and flexible operation of the deep peak-shaving steam turbine, and thereby make the long life and flexible operation of the deep peak-shaving steam turbine reach the set target as much as possible.

[0095] Figure 3 A schematic flow chart of a closed-loop control method based on relative stress margin for a deep peak-shaving steam turbine provided in an embodiment of the present application. Figure 3 As shown, the method includes but is not limited to the following steps:

[0096] S301, obtaining thermal stress and mechanical stress of high-temperature key components of the deep peak-shaving steam turbine in various directions.

[0097] Optionally, the radial thermal stress σ of the inner surface of the main steam valve housing, the regulating valve housing and the high-temperature outer cylinder of the steam turbine and the outer surface of the high-temperature rotor rth(τ), tangential thermal stress σ θth (τ) and axial thermal stress σ zth The calculation formulas for (τ) are

[0098] σ rth (τ)=0 (2)

[0099]

[0100] Among them, α jk (τ) is the material linear expansion coefficient of high temperature key components, E jk (τ) is the material elastic modulus of high temperature key components, Δt jk (τ) Temperature difference of key high-temperature components of steam turbine, μ jk (τ) is the material Poisson’s ratio of high-temperature critical components.

[0101] Optionally, the mechanical stress of the high-temperature turbine rotor is the rotor centrifugal stress, and the radial centrifugal stress σ on the outer surface of the turbine rotor is rm (τ), tangential centrifugal stress σ θm (τ) and axial centrifugal stress σ zm The online calculation formulas for (τ) are

[0102]

[0103]

[0104]

[0105] Among them, σ rm0 is the finite element calculated value of the radial centrifugal stress at the part with large temperature difference of the high-temperature rotor at rated operating speed of the steam turbine, n is the online monitoring value of the steam turbine operating speed, n0 is the rated operating speed of the steam turbine, σ θm0 is the finite element calculated value of the tangential centrifugal stress at the part with large temperature difference of the high temperature rotor of the steam turbine at rated operating speed, σ zm0 It is the finite element calculated value of the axial centrifugal stress at the location where the temperature difference of the high-temperature rotor is relatively large at the rated operating speed of the turbine.

[0106] Optionally, the radial mechanical stress σ of the main steam valve housing, regulating valve housing and inner surface of the high-temperature outer cylinder of the steam turbine is rm (τ), tangential mechanical stress σ θm (τ) and axial mechanical stress σ zm The calculation formulas for (τ) are:

[0107] σ rm (τ)=-p1 (7)

[0108]

[0109] σ zm (τ)=0 (9)

[0110] Among them, p1 is the pressure on the inner surface of the cylinder wall, r1 is the radius of the inner surface of the cylinder wall, and r n is the radius of the outer surface of the cylinder wall.

[0111] S302, determining the composite stress of the high-temperature key component in each direction according to the thermal stress in each direction and the mechanical stress in each direction.

[0112] Optionally, the radial composite stress σ of the high-temperature key components of the steam turbine r (τ), tangential composite stress σ θ (τ) and the axial composite stress σ z The calculation formulas for (τ) are:

[0113] σ r (τ)=σ rm (τ)+σ rm (τ) (10)

[0114] σ θ (τ)=σ θth (τ)+σ θm (τ) (11)

[0115] σ z (τ)=σ zth (τ)+σ zm (τ) (12)

[0116] Among them, σ rth (τ) is the radial thermal stress of high temperature key components, σ rm (τ) is the radial mechanical stress of high temperature key components, σ θth (τ) is the tangential thermal stress of high-temperature key components, σ θm (τ) is the tangential mechanical stress of high temperature key components, σ zth (τ) is the axial thermal stress of high-temperature key components, σ zm Axial mechanical stress.

[0117] S303, determining a second equivalent stress of the high temperature key component according to the composite stress of the high temperature key component in each direction.

[0118] The difference of the composite stress in each two directions is obtained, and the second equivalent stress of the high-temperature key component is determined according to the difference of the composite stress.

[0119] Optionally, the second equivalent stress σ of the high temperature critical component eqjk The calculation formula of (τ) is:

[0120]

[0121] Among them, σ r (τ) is the radial composite stress of high temperature key components, σ θ (τ) is the tangential composite stress of high-temperature key components, σ z (τ) is the axial composite stress of high-temperature key components.

[0122] S204, determining a maximum composite stress and a minimum composite stress from the composite stresses in each direction.

[0123] Optionally, the maximum composite stress σ of the high-temperature key components of the steam turbine max The calculation formula of (τ) is:

[0124] σ max (τ)=max{σ r (τ), σ θ (τ), σ z (τ)} (14)

[0125] Among them, σ r (τ) is the radial composite stress of high temperature key components, σ θ (τ) is the tangential composite stress of high-temperature key components, σ z (τ) is the axial composite stress of high-temperature key components.

[0126] Optionally, the minimum composite stress σ of the high-temperature key components of the steam turbine min The calculation formula of (τ) is:

[0127] σ min (τ)=min{σ r (τ), σ θ (τ), σ z (τ)} (15)

[0128] S305, determining the first equivalent stress of the high-temperature key component according to the second equivalent stress, the maximum combined stress and the minimum combined stress of the high-temperature key component.

[0129] Optionally, the first equivalent stress σ with positive and negative signs of the high temperature key components of the steam turbine ejk The calculation formula of (τ) is:

[0130] σ ejk (τ)=σ eqjk (τ)×sign[σ max (τ)+σ min (τ)] (16)

[0131] Among them, σ eqjk (τ) is the equivalent stress of high temperature key components, σmax (τ) is the maximum composite stress of high temperature key components, σ min (τ) is the minimum composite stress of the high-temperature key component, sign(x) is the sign function, if x>0, then sign(x)=1, if x<0, then sign(x)=-1.

[0132] S306, obtaining the allowable limit stress of the material of the high-temperature key components.

[0133] S307, obtaining the difference between the ratio of the first equivalent stress and the allowable limit stress of the material, and determining the relative stress margin of the high-temperature key component according to the difference and the absolute value of the first equivalent stress.

[0134] S308, comparing the relative stress margin of each high-temperature key component, and determining the minimum value as the minimum relative stress margin of the steam turbine.

[0135] S309, controlling the speed and load of the steam turbine under target operating conditions according to the minimum relative stress margin.

[0136] For a detailed introduction to steps S306 to S309, please refer to the implementation methods in the various embodiments of the present application, which will not be repeated here.

[0137] In an embodiment of the present application, the thermal stress of the high-temperature key components can be determined based on the temperature difference and material physical properties of the high-temperature key components, and the mechanical stress of the high-temperature key components can be determined based on relevant basic data. Further, based on the thermal stress and mechanical stress, the first equivalent stress with positive and negative signs of the high-temperature key components can be determined to provide a calculation basis for stress-related data and life-related data for subsequent turbine control, so that closed-loop control based on stress and life can be performed to improve the long life and flexible operation of the turbine.

[0138] Figure 4 A schematic diagram of a process for obtaining the first equivalent stress of a high-temperature key component provided in an embodiment of the present application. Figure 4 As shown, the method includes but is not limited to the following steps:

[0139] S401, obtaining basic data related to stress of high-temperature key components.

[0140] Optionally, basic data for calculating the high-temperature rotor volume average temperature and center temperature include:

[0141] The radius r of the rotor outer surface of the high temperature rotor calculation section n, calculate the coefficients A1, A2 and A3 of the time constant T1 of the first inertia link, calculate the proportional coefficient E2 of the time constant of the second inertia link, calculate the proportional coefficient E3 of the time constant of the third inertia link, calculate the proportional coefficient E4 of the time constant of the fourth inertia link, calculate the proportional coefficient E5 of the time constant of the fifth inertia link, calculate the proportional coefficient E6 of the time constant of the sixth inertia link, the weight coefficient K1 of the first inertia link, the weight coefficient K2 of the second inertia link, the weight coefficient K3 of the third inertia link, the weight coefficient K4 of the fourth inertia link, the weight coefficient K5 of the fifth inertia link, and the weight coefficient K6 of the sixth inertia link.

[0142] The metal temperatures of the high-temperature critical components at the depths of 50% and 90% of the wall thickness at time τ are t jk50 %(τ) and t jk90 %(τ), the metal temperature of the measuring point is taken from the steam turbine digital electro-hydraulic control system DEH or the steam turbine control system TCS.

[0143] Material linear expansion coefficient α of high temperature key components jk (τ), material elastic modulus E jk (τ), material Poisson's ratio μ jk (τ), subscript j indicates the working environment of key components, V indicates ultra-high pressure, H indicates high pressure, and I indicates medium pressure. Subscript k indicates the name of steam turbine components, S indicates the main steam valve housing, A indicates the regulating valve housing, R indicates the rotor, C indicates the outer cylinder, and O indicates the inner cylinder.

[0144] The outer surface radius r of the main steam valve housing, regulating valve housing and high-temperature outer cylinder n , inner surface radius r1, inner surface steam pressure p1, turbine operating speed n, turbine rated operating speed n0, finite element calculation value of radial centrifugal stress at the rotor monitoring point of the turbine at rated operating speed σ rm0 , the finite element calculated value of the tangential centrifugal stress at the rotor monitoring point of the steam turbine at the rated operating speedσ θm0 , the finite element calculated value of the axial centrifugal stress at the rotor monitoring point of the steam turbine at the rated operating speedσ zm0 .

[0145] S402, obtaining the outer surface temperature of the high-temperature rotor of the steam turbine.

[0146] Optionally, the metal temperature t at the depth of 90% of the inner cylinder wall thickness of the corresponding part is used. jO90 %(τ) replaces the high temperature rotor outer surface temperature t n .

[0147] S403, determining three inertia link time constants required for the high-temperature rotor volume average temperature.

[0148] Optionally, the online calculation formulas for the first inertia link time constant T1, the second inertia link time constant T2 and the third inertia link time constant T3 required for calculating the volume average temperature of the high-temperature rotor are respectively:

[0149]

[0150]

[0151]

[0152] Among them, r n is the radius of the rotor outer surface of the high temperature rotor calculation section, A1, A2 and A3 are the coefficients for calculating the time constant T1 of the first inertia link, t vm(m-1) is the output value of the previous calculation of the high-temperature rotor volume average temperature, E2 is the proportional coefficient for calculating the time constant of the second inertia link, and E3 is the proportional coefficient for calculating the time constant of the third inertia link.

[0153] S404, determining the volume average temperature of the high temperature rotor

[0154] Figure 4a A schematic diagram of a process for determining the average volume temperature of a high-temperature rotor provided in an embodiment of the present application, according to Figure 4a The method shown in the figure shows that the volume average temperature of the high-temperature rotor of the turbine is t jvm The calculation formula of (τ) is

[0155]

[0156] Among them, t jO90％ (τ) is the metal temperature at a depth of 90% of the inner cylinder wall thickness.

[0157] S405, determining six inertia link time constants required for the high-temperature rotor center temperature.

[0158] Optionally, the calculation formulas for the first inertia link time constant T1, the second inertia link time constant T2, the third inertia link time constant T3, the fourth inertia link time constant T4, the fifth inertia link time constant T5 and the sixth inertia link time constant T6 required for calculating the center temperature of the high-temperature rotor of the steam turbine are respectively:

[0159]

[0160]

[0161]

[0162]

[0163]

[0164]

[0165] Among them, r n is the radius of the rotor outer surface of the high temperature rotor calculation section, A1, A2 and A3 are the coefficients for calculating the time constant T1 of the first inertia link, t vm(m-1) is the output value of the previous calculation of the high-temperature rotor volume average temperature, E2 is the proportional coefficient for calculating the time constant of the second inertia link, E3 is the proportional coefficient for calculating the time constant of the third inertia link, E4 is the proportional coefficient for calculating the time constant of the fourth inertia link, E5 is the proportional coefficient for calculating the time constant of the fifth inertia link, and E6 is the proportional coefficient for calculating the time constant of the sixth inertia link.

[0166] S406, determining the center temperature of the high temperature rotor

[0167] Figure 4b This is a schematic diagram of online calculation of the high temperature rotor center temperature according to an embodiment of the present disclosure. Figure 4b The method shown, the turbine high temperature rotor center temperature t j1 The calculation formula of (τ) is

[0168]

[0169] Among them, t jO90％ (τ) is the metal temperature at a depth of 90% of the inner cylinder wall thickness.

[0170] S407, determining the temperature difference of the high temperature rotor.

[0171] Optionally, the temperature difference Δt of the high temperature rotor of the steam turbine jR The online calculation formula for (τ) is:

[0172] Δt jR (τ) = t jvm (τ)-t jO90％ (τ) (28)

[0173] Among them, t jvm (τ) is the average temperature of the high temperature rotor volume, t jO90％ (τ) is the metal temperature at a depth of 90% of the inner cylinder wall thickness.

[0174] S408, determining the center temperature difference of the high-temperature rotor.

[0175] Optionally, the turbine high temperature rotor center temperature difference Δt j1 The calculation formula of (τ) is

[0176] Δt j1 (τ) = t jvm(τ)-t j1 (τ) (29)

[0177] Among them, t jvm (τ) is the average temperature of the high temperature rotor volume, t j1 (τ) is the center temperature of the high temperature rotor.

[0178] S409, determining the temperature difference of the high temperature rotor.

[0179] Optionally, the temperature difference of the high-temperature rotor is determined according to the surface temperature difference and the center temperature difference of the high-temperature rotor, wherein the temperature difference Δt of the high-temperature rotor is jk The calculation formula of (τ) is

[0180] Δt jk (τ)=max{Δt jR (τ),Δt j1 (τ)} (30)

[0181] Among them, Δt jR (τ) is the high temperature rotor surface temperature difference, Δt j1 (τ) is the center temperature difference of the high-temperature rotor.

[0182] S410, determining the temperature difference between the main steam valve housing, the regulating valve housing and the high-temperature outer cylinder.

[0183] Optionally, the temperature difference Δt between the main steam valve housing, the regulating valve housing and the high-temperature outer cylinder of the steam turbine is jk The calculation formula of (τ) is

[0184] Δt jk (τ) = t jk50％ (τ)-t jk90％ (τ) (31)

[0185] Among them, t jk50％ (τ) is the metal temperature at the measuring point at a depth of 50% of the wall thickness, which can be used as the volume average temperature t of the main steam valve housing, regulating valve housing and high-temperature outer cylinder jkvm (τ), t jk90％ (τ) is the metal temperature of the measuring point at 90% of the cylinder wall thickness of the main steam valve housing, regulating valve housing and high-temperature outer cylinder.

[0186] S411, determine thermal stresses in high temperature critical components.

[0187] For a detailed description of step S411, please refer to the relevant contents of step S301, which will not be repeated here.

[0188] S412, determining the mechanical stress of the high temperature rotor.

[0189] For a detailed description of step S412, please refer to the relevant contents of step S301, which will not be repeated here.

[0190] S413, determine the mechanical stress of the main steam valve housing, the regulating valve housing and the high-temperature outer cylinder.

[0191] For a detailed description of step S413, please refer to the relevant contents of step S301, which will not be repeated here.

[0192] S414, determine the resultant stresses of high temperature critical components.

[0193] For a detailed description of step S414, please refer to the relevant contents in step S302, which will not be repeated here.

[0194] S415, determine the maximum composite stress of high temperature critical components.

[0195] For a detailed description of step S415, please refer to the relevant contents of step S304, which will not be repeated here.

[0196] S416, determine the minimum resultant stress of high temperature critical components.

[0197] For a detailed description of step S416, please refer to the relevant contents of step S304, which will not be repeated here.

[0198] S417, determine the second equivalent stress of high temperature key components.

[0199] For a detailed description of step S417, please refer to the relevant contents of step S303, which will not be repeated here.

[0200] S418, determine the first equivalent stress with positive and negative signs of high temperature key components.

[0201] For a detailed description of step S418, please refer to the relevant contents of step S305, which will not be repeated here.

[0202] For example, for a supercritical 1050MW single reheat steam turbine with a main steam temperature of 600°C, the basic data for calculating the average volume temperature of the high-pressure rotor of this turbine are listed in Table 1, and the basic data for calculating the center temperature of the high-pressure rotor are listed in Table 2.

[0203] The time τ of the steam turbine during warm start-up is 10000s, and the metal temperature t at the 90% depth of the high-pressure inner cylinder wall thickness corresponding to the high-pressure rotor thermal stress and life monitoring point is HO90％ (τ)=573.6℃.

[0204] Table 1 Basic data for calculating the average volume temperature of the high-pressure rotor

[0205] Serial number project High pressure rotor 1 <![CDATA[Outer diameter r of high-pressure rotor n (mm) > 445 2 <![CDATA[Coefficient A1 of the time constant of the first inertia link]]> 26080.2 3 <![CDATA[Coefficient A2 of the time constant of the first inertia link]]> -15.9735 4 <![CDATA[Coefficient A3 of the time constant of the first inertia link]]> <![CDATA[-1.47646×10 -4 ]]> 5 <![CDATA[Proportionality coefficient E2 of the second inertia link time constant]]> 5.27 6 <![CDATA[Proportionality coefficient E3 of the time constant of the third inertia link]]> 12.0 7 <![CDATA[Weight coefficient K1 of the first inertia link]]> 0.6917 8 <![CDATA[Weight coefficient K2 of the second inertia link]]> 0.1313 9 <![CDATA[Weight coefficient K3 of the third inertia link]]> 0.1770

[0206] Table 2 Basic data for calculating the center temperature of the high pressure rotor

[0207] Serial number project High pressure rotor 1 <![CDATA[Outer diameter r of high-pressure rotor n ( mm ) > 445 2 <![CDATA[Coefficient A1 of the time constant of the first inertia link]]> 26080.2 3 <![CDATA[Coefficient A2 of the time constant of the first inertia link]]> -15.9735 4 <![CDATA[Coefficient A3 of the time constant of the first inertia link]]> <![CDATA[-1.47646×10 -4 ]]> 5 <![CDATA[Proportionality coefficient E2 of the second inertia link time constant]]> 5.27 6 <![CDATA[Proportionality coefficient E3 of the time constant of the third inertia link]]> 12.95 7 <![CDATA[Proportionality coefficient E4 of the time constant of the fourth inertia link]]> 24.04 8 <![CDATA[Proportionality coefficient E5 of the time constant of the fifth inertial link]]> 38.56 9 <![CDATA[Proportionality coefficient E6 of the time constant of the sixth inertial link]]> 53.00 10 <![CDATA[Weight coefficient K1 of the first inertia link]]> 1.5992 11 <![CDATA[Weight coefficient K2 of the second inertia link]]> -1.0647 12 <![CDATA[Weight coefficient K3 of the third inertia link]]> 0.8529 13 <![CDATA[Weight coefficient K4 of the fourth inertia link]]> -0.7301 14 <![CDATA[Weight coefficient K5 of the fifth inertia link]]> 0.6471 15 <![CDATA[Weight coefficient K6 of the sixth inertia link]]> -0.3044

[0208] The sampling calculation time of the high-pressure inner cylinder temperature of this steam turbine is taken as τ s =4s, at the moment of warm start process τ = 10000s, at (τ-τ s )=9996s, the average volume temperature of the high-pressure rotor of the steam turbine is t vm(m-1) =483.8℃, metal temperature at 90% depth of high pressure inner cylinder wall thickness t HO90％ (τ) = 573.6°C. The online calculation results of the first inertia link time constant T1, the second inertia link time constant T2 and the third inertia link time constant T3 required for the calculation of the average volume temperature of the high-pressure rotor of the steam turbine are respectively

[0209]

[0210]

[0211]

[0212] The average volume temperature of the high-pressure rotor of the steam turbine is t Hvm The calculation results are:

[0213]

[0214] The calculation results of the first inertia link time constant T1, the second inertia link time constant T2, the third inertia link time constant T3, the fourth inertia link time constant T4, the fifth inertia link time constant T5, and the sixth inertia link time constant T6 required for the calculation of the center temperature of the high-pressure rotor of the steam turbine are respectively

[0215]

[0216]

[0217]

[0218]

[0219]

[0220]

[0221] The central temperature of the high pressure rotor of the steam turbine is tH1 The calculation result of (τ) is:

[0222]

[0223] The single-reheat steam turbine was started in warm state for 10000s. The online calculation data of stress of high-temperature components of high-pressure cylinder are listed in Table 3. The online calculation data of stress include thermal stress, mechanical stress, synthetic stress, second equivalent stress and first equivalent stress with positive and negative signs at the monitoring points of the inner surface of high-pressure main steam valve housing, the inner surface of high-pressure regulating valve housing, the outer surface of high-pressure rotor and the inner surface of high-pressure outer cylinder.

[0224] Table 3 Calculation data of stress of high-temperature components of high-pressure cylinder

[0225] Serial number project High pressure main steam valve housing High pressure regulating valve housing High pressure rotor High pressure outer cylinder 1 <![CDATA[Volume-averaged temperature t jkvm (τ) (°C)]]> 541.2 541.2 483.8 326.7 2 <![CDATA[Surface temperature t jk90％ (τ) (°C)]]> 583.0 582.9 573.6 376.8 3 <![CDATA[Temperature difference Δt jk (τ) (°C)]]> -41.8 -41.7 -89.8 -50.1 4 <![CDATA[Radial thermal stress σ rth (τ) (MPa)]]> 0 0 0 0 5 <![CDATA[Tangential thermal stress σ θth (τ) (MPa)]]> -125.585 -125.284 -383.846 -183.424 6 <![CDATA[Axial thermal stress σ zth (τ) (MPa)]]> -125.585 -125.284 -383.846 -183.424 7 <![CDATA[Radial mechanical stress σ rm (τ) (MPa)]]> -25.738 -25.738 0 -5.950 8 <![CDATA[Tangential mechanical stress σ θm (τ) (MPa)]]> 52.373 39.218 20.807 39.298 9 <![CDATA[Axial mechanical stress σ zm (τ) (MPa)]]> 0 0 6.450 0 10 <![CDATA[Radial composite stress σ r (τ) (MPa)]]> -25.738 -25.738 0 -5.950 11 <![CDATA[Tangential combined stress σ θ (τ) (MPa)]]> -73.212 -86.066 383.846 -144.126 12 <![CDATA[Axial combined stress σ z (τ) (MPa)]]> -125.585 -125.284 -377.396 -183.424 13 <![CDATA[Maximum combined stress σ max (τ) (MPa)]]> -25.738 -25.738 0 -5.950 14 <![CDATA[Minimum combined stress σ min (τ) (MPa)]]> -125.585 -125.284 -383.846 -183.424 15 <![CDATA[The second equivalent stress σ eqjk (τ) (MPa)]]> 86.505 86.853 380.662 161.453 16 <![CDATA[First equivalent stress σ ejk (τ) (MPa)]]> -86.505 -86.853 -380.662 -161.453

[0226] In an embodiment of the present application, the thermal stress of the high-temperature key components can be determined based on the temperature difference and material physical properties of the high-temperature key components, and the mechanical stress of the high-temperature key components can be determined based on relevant basic data. Further, based on the thermal stress and mechanical stress, the first equivalent stress with positive and negative signs of the high-temperature key components can be determined to provide a calculation basis for stress-related data and life-related data for subsequent turbine control, so that closed-loop control based on stress and life can be performed to improve the long life and flexible operation of the turbine.

[0227] Figure 5 FIG. 1 is a flow chart of a closed-loop control method based on relative stress margin for a deep peak-shaving steam turbine according to an embodiment of the present disclosure. Based on the above implementation, as shown in FIG. Figure 5 As shown, the following steps are included:

[0228] S501, obtaining basic data related to stress of high-temperature key components.

[0229] Optionally, obtain the material yield strength of high temperature critical components The material has a rupture time of 5000h. Subscript j indicates the working environment of key components, V indicates ultra-high pressure, H indicates high pressure, and I indicates medium pressure. Subscript k indicates the name of turbine components, S indicates the main steam valve housing, A indicates the regulating valve housing, R indicates the rotor, and C indicates the outer cylinder.

[0230] S502, determining the material creep limit temperature of high-temperature key components.

[0231] Optionally, the creep limit temperature of carbon steel material of high-temperature key components of steam turbine is 350°C, the creep limit temperature of alloy steel material of high-temperature key components of steam turbine is 420°C, the creep limit temperature of heat-resistant steel material of high-temperature key components of steam turbine is 480°C, and the creep limit temperature of nickel-based alloy material of high-temperature key components of steam turbine is 650°C.

[0232] S503, determining the allowable limit stress of the material when the working temperature is greater than or equal to the creep limit temperature of the material.

[0233] Optionally, the operating temperature of the high-temperature key component is greater than or equal to the material creep limit temperature of the material allowable limit stress σ pujk The formula for (τ) is

[0234]

[0235] in, is the material yield limit of high temperature key components, The creep rupture time of high temperature key components is t r =Material endurance strength of 5000h.

[0236] S504, determining the allowable limit stress of the material when the working temperature is lower than the creep limit temperature of the material.

[0237] Optionally, the operating temperature of the high-temperature key components of the steam turbine is less than the material creep limit temperature of the material allowable limit stress σ pujk The formula for (τ) is

[0238]

[0239] That is to say, if the operating temperature of the high-temperature key component is greater than or equal to the material creep limit temperature, the allowable limit stress σ of the material can be determined according to the above formula (31): pujk (τ); If the operating temperature of the high-temperature key component is lower than the material creep limit temperature, the allowable limit stress σ of the material can be determined according to the above formula (32): pujk (τ).

[0240] S505: Determine a first equivalent stress based on the basic data.

[0241] For a detailed description of step S505, reference may be made to the first equivalent stress determination process described in the above embodiment, which will not be described in detail here.

[0242] S506, obtaining the difference between the absolute value of the first equivalent stress and the allowable limit stress of the material, and determining the relative stress margin of the high-temperature key component according to the difference and the absolute value of the first equivalent stress.

[0243] Optionally, the relative stress margin R of the high temperature key components of the steam turbine sjk (τ), R sis the relative stress margin, where subscript j represents the working environment of key components, V represents ultra-high pressure, H represents high pressure, and I represents medium pressure. Subscript k represents the name of the turbine component, S represents the main steam valve housing, A represents the regulating valve housing, R represents the rotor, and C represents the outer cylinder. sjk The calculation formula of (τ) is:

[0244]

[0245] Among them, σ pujk (τ) represents the material allowable limit stress of high temperature key components, σ ejk (τ) represents the first equivalent stress with positive and negative signs of high temperature key components.

[0246] S507, determine the minimum relative stress margin of the steam turbine.

[0247] (1) Optionally, for a double reheat steam turbine, the minimum relative stress margin R smin The calculation formula of (τ) is:

[0248]

[0249] Among them, R sVS (τ) is the relative stress margin of the inner surface of the super-high pressure main steam valve of the steam turbine, R sVA (τ) is the relative stress margin of the inner surface of the super-high pressure regulating valve of the steam turbine, R sVR (τ) is the relative stress margin of the ultra-high pressure rotor of the steam turbine, R sVC (τ) is the relative stress margin of the inner surface of the super-high pressure outer cylinder of the steam turbine, R sHS (τ) is the relative stress margin of the inner surface of the high-pressure main steam valve of the steam turbine, S sHA (τ) is the relative stress margin of the inner surface of the high-pressure regulating valve of the steam turbine, R sHR (τ) is the relative stress margin of the high pressure rotor of the steam turbine, R sHC (τ) is the relative stress margin of the inner surface of the high-pressure outer cylinder of the steam turbine, R sIS (τ) is the relative stress margin of the inner surface of the medium-pressure main steam valve of the steam turbine, R sIA (τ) is the relative stress margin of the inner surface of the medium-pressure regulating valve of the steam turbine, R sIR (τ) is the relative stress margin rate of the outer surface of the intermediate pressure rotor of the steam turbine, R sIC (τ) is the relative stress margin of the inner surface of the medium-pressure outer cylinder of the turbine.

[0250] (2) For a single reheat steam turbine, the minimum relative stress margin R smin The calculation formula of (τ) is:

[0251] R smin(τ)=min{R sHS (τ),R sHA (τ),R sHR (τ),R sHC (τ),R sIS (τ),R sIA (τ),R sIR (τ),R sIC (τ)}(36)

[0252] (3) For a steam turbine without reheat, the minimum relative stress margin R smin The calculation formula of (τ) is:

[0253] R smin (τ)=min{R sHS (τ),R sHA (τ),R sHR (τ),R sHC (τ)} (37)

[0254] The above steps S501 to S507 can be used to determine the minimum relative stress margin of the steam turbine as an independent embodiment. Optionally, after obtaining the minimum relative stress margin, the steam turbine can be closed-loop controlled based on the minimum relative stress margin. The specific process can be found in the following steps S508 to S514. That is, after obtaining the minimum relative stress margin, steps S508 to S514 can form an independent embodiment of closed-loop control of the steam turbine based on the minimum relative stress margin.

[0255] S508, based on the minimum relative stress margin, determine the speed change rate V of the steam turbine n2 and load change rate V N2 The correction factor of .

[0256] In the embodiment of the present application, based on the minimum relative stress margin R of the steam turbine smin (τ), determine the speed change rate V n2 and load change rate V N2 Correction factor C R The calculation formula is:

[0257]

[0258] S509, determine the set value of the turbine speed change rate.

[0259] Get the set value n of the turbine speed change rate s , n s =4~16%n0[(r / min) / min], where n0 is the rated speed of the turbine (r / min), and optionally, n0 can be used for slow start or shutdowns Take the lower limit, normal start or shutdown n s Take the middle value, fast start or stop n s Take the upper limit value.

[0260] S510, determining a set value of the turbine speed change rate.

[0261] Get the set value N of the turbine load change rate s , N s =3~5%TMCR(MW / min), where TMCR is the maximum continuous power of the turbine (MW). Optionally, the load can be increased or decreased below 30%TMCR. s Take the lower limit value, increase or decrease the load within the load range of 30% to 50% TMCR N s Take the middle value, increase or decrease the load within the load range of 50% to 100% TMCR s Take the upper limit value.

[0262] S511, based on correction factor C R , determine the turbine speed change rate V n2 .

[0263] Optionally, based on the correction factor C R , turbine speed change rate V n2 The calculation formula is:

[0264] V n2 =C R n s [(r / min) / min (39)

[0265] S512, based on the speed change rate V n2 Closed-loop control of the turbine speed is performed.

[0266] According to the turbine speed change rate V n2 , closed-loop control is performed on the turbine speed before grid connection during the startup process and the turbine speed after disconnection during the shutdown process.

[0267] Optionally, during the turbine startup process, if the speed change rate V n2 =0, which means keeping the turbine speed unchanged and warming up the turbine; if the speed change rate V n2 A negative value indicates the speed change rate V during the speed increase process. n2 If it is a negative value, the turbine speed should be reduced.

[0268] During the turbine shutdown process, if the speed change rate V n2 =0, indicating that the turbine speed remains unchanged; if the speed change rate V n2 A negative value indicates the speed change rate V during the deceleration processn2 If it is a negative value, the turbine speed should be increased.

[0269] If the speed is increased or decreased, R smin (τ)<-0.5, indicating that the relative stress margin of the high-temperature key components of the turbine is too small and an emergency shutdown is required after one minute.

[0270] The hydraulic actuator of the DEH or TCS of the steam turbine responds to the speed change rate V based on the relative stress margin n2 Closed-loop control instruction, to perform closed-loop control on the speed of the turbine.

[0271] S513, based on correction factor C R , determine the turbine load change rate V N2 .

[0272] Optionally, based on the turbine load change rate V N2 Correction factor C R , determine the turbine load change rate V N2 The calculation formula is:

[0273] V N2 =C R N s (MW / min)(40)

[0274] S514, based on the load change rate V N2 Closed-loop control of turbine load is performed.

[0275] According to the load change rate V of the steam turbine N2 , closed-loop control is performed on the turbine load after grid connection during the startup process and the turbine load before disconnection during the shutdown process.

[0276] Optionally, during the turbine startup load increase process, if the load change rate V N2 =0, indicating that the load change rate of the steam turbine is kept at zero, that is, the load change rate during the load increase process is 0MW / min; if the load change rate V N2 A negative value indicates that the load change rate during the load increase process is negative, that is, the turbine should reduce load.

[0277] During the turbine shutdown and load reduction process, if the load change rate V N2 =0, indicating that the load change rate of the steam turbine is kept at zero, that is, the load change rate during the load reduction process is 0MW / min; if the load change rate V N2 A negative value indicates that the load change rate during the load reduction process is negative, that is, the turbine should increase its load.

[0278] If the load is increased or decreased, R smin(τ)<-0.5, indicating that the relative stress margin of the high-temperature key components of the turbine is too small and an emergency shutdown is required after one minute.

[0279] The hydraulic actuator of the DEH or TCS of the steam turbine responds to the load change rate V based on the relative stress margin N2 Closed-loop control instructions perform closed-loop control on the turbine load.

[0280] For example, for a supercritical 1050MW single-reheat steam turbine, the first equivalent stress σ with positive and negative signs on the high-temperature key components of the turbine during the transient load increase condition at time τ after the turbine is connected to the grid ejk (τ) and the allowable limit stress σ of the material of the high-temperature key components of the steam turbine at this moment τ pujk The calculation data of (τ) is shown in Table 4 in the above embodiment.

[0281] Table 4 The first equivalent stress σ ejk (τ) and material allowable limit stress σ pujk Calculation data of (τ)

[0282]

[0283] Based on the above Table 4, the relative stress margin R of the high temperature key components of the supercritical 1050MW single reheat steam turbine at time τ is sjk The calculation data of (τ) are listed in Table 5. The minimum relative stress margin R smin (τ)=0.13.

[0284] Table 5 Calculation data of relative stress margin of high temperature key components

[0285] Serial number Part Name <![CDATA[Relative stress margin R sjk (τ)]]> 1 Inner surface of high pressure main steam valve housing 2.91 2 Inner surface of high pressure regulating valve housing 1.98 3 High pressure rotor 0.13 4 Inner surface of high pressure outer cylinder 1.63 5 Inner surface of medium pressure main steam valve housing 2.19 6 Inner surface of medium pressure regulating valve housing 5.42 7 Medium pressure rotor 0.44 8 Inner surface of medium pressure outer cylinder 0.95

[0286] The minimum relative stress margin R of the steam turbine smin (τ) is between 0 and 1.0, the correction coefficient C of the load change rate at time τ R The calculation result is

[0287] C R =1+0.5R smin =1+0.5×0.13=1.065

[0288] At time τ, the load of the steam turbine is within the range of 50% to 100% TMCR load, and the set value of the load change rate of the steam turbine is N s =5%TMCR(MW / min), the load change rate of the steam turbine is:

[0289] V N2 =C R N s=1.065×5%TMCR=5.325%TMCR(MW / min)

[0290] The hydraulic actuator of the DEH or TCS of the steam turbine responds to the load change rate V based on the minimum relative stress margin. N2 =5.325%TMCR (MW / min) closed-loop control instruction to control the load of the turbine.

[0291] In the embodiments of the present application, in order to achieve long life and flexible operation of the steam turbine, the relative stress margin of high-temperature key components can be monitored, and based on such monitoring data, the change rate of the operating parameters can be determined to adjust the operating parameters according to the change rate. That is, during the startup process, shutdown process or load change process of the steam turbine, the turbine speed before grid connection and after decoupling, as well as the turbine load after grid connection and before decoupling are closed-loop controlled, which can not only reasonably extend the life of the steam turbine, but also improve the flexibility of the steam turbine, so as to achieve long life and flexible operation of the deep peak-shaving steam turbine, and thereby make the long life and flexible operation of the deep peak-shaving steam turbine reach the set target as much as possible.

[0292] Figure 6 Schematic diagram of the structure of a closed-loop control device based on relative stress margin for a deep peak-shaving steam turbine according to an embodiment of the present disclosure, as shown in FIG. Figure 6 As shown, the closed-loop control device 600 may include: a first acquisition module 601 , a second acquisition module 602 , a third acquisition module 603 and a control module 604 .

[0293] A first acquisition module 601 is used to acquire a first equivalent stress of a high-temperature key component of a deep peak-shaving steam turbine, and acquire an absolute value of the first equivalent stress, wherein the first equivalent stress has positive and negative properties;

[0294] The second acquisition module 602 is used to obtain the allowable limit stress of the material of the high-temperature key component;

[0295] A third acquisition module 603 is used to obtain a difference between the absolute value of the first equivalent stress and the allowable limit stress of the material, and determine a relative stress margin of the high-temperature key component according to the difference and the absolute value of the first equivalent stress;

[0296] The control module 604 is used to perform closed-loop control on the speed and load of the steam turbine under target operating conditions according to the relative stress margin of the high-temperature key components.

[0297] In some implementations, the second acquisition module 602 is further configured to:

[0298] Determine the material yield limit of the high temperature key component and the material endurance strength of the high temperature key component with a creep rupture time of a set time;

[0299] The allowable limit stress of the material of the high-temperature key component is determined according to the material yield limit of the high-temperature key component and the material endurance strength.

[0300] In some implementations, the second acquisition module 602 is further configured to:

[0301] Determine, according to the material yield limit of the high-temperature key component and the material endurance strength, a first material allowable limit stress when the operating temperature is greater than or equal to the material creep limit temperature, and a second material allowable limit stress when the operating temperature is less than the material creep limit temperature;

[0302] According to the current operating temperature of the steam turbine, the material allowable limit stress of the high-temperature key component is determined from the first material allowable limit stress and the second material allowable limit stress.

[0303] In some implementations, the second acquisition module 602 is further configured to:

[0304] Determining whether the current operating temperature is greater than or equal to the material creep limit temperature;

[0305] If the current operating temperature is greater than or equal to the material creep limit temperature, determining the material allowable limit stress of the high-temperature key component to be the first material allowable limit stress;

[0306] If the current operating temperature is lower than the material creep limit temperature, the material allowable limit stress of the high-temperature key component is determined to be the second material allowable limit stress.

[0307] In some implementations, the second acquisition module 602 is further configured to:

[0308] Determine a minimum value from the material yield limit of the high-temperature key component and the material endurance strength, and determine the minimum value as the first material allowable limit stress;

[0309] Wherein, the allowable limit stress of the second material is the material yield limit of the high-temperature key component.

[0310] In some implementations, the control module 604 is further configured to:

[0311] Comparing the relative stress margins of each of the high-temperature key components, and determining a minimum value therefrom as the minimum relative stress margin of the steam turbine;

[0312] The rotation speed and load under the target working condition are controlled according to the minimum relative stress margin.

[0313] In some implementations, the control module 604 is further configured to:

[0314] Determining correction coefficients corresponding to the speed change rate and the load change rate according to the minimum stress safety multiple;

[0315] Obtaining a product of the correction coefficient and a speed change rate setting value as the speed change rate of the speed, and controlling the speed under the target operating condition according to the speed change rate;

[0316] The product of the correction coefficient and the load change rate setting value is obtained as the load change rate of the load, and the load under the target working condition is controlled according to the load change rate.

[0317] In some implementations, the control module 604 is further configured to:

[0318] If the minimum stress safety multiple is within the emergency shutdown range, the steam turbine is controlled to perform an emergency shutdown operation after a set time.

[0319] In the embodiments of the present application, in order to achieve long life and flexible operation of the steam turbine, the relative stress margin of high-temperature key components can be monitored, and based on such monitoring data, the change rate of the operating parameters can be determined to adjust the operating parameters according to the change rate. That is, during the startup process, shutdown process or load change process of the steam turbine, the turbine speed before grid connection and after decoupling, as well as the turbine load after grid connection and before decoupling are closed-loop controlled, which can not only reasonably extend the life of the steam turbine, but also improve the flexibility of the steam turbine, so as to achieve long life and flexible operation of the deep peak-shaving steam turbine, and thereby make the long life and flexible operation of the deep peak-shaving steam turbine reach the set target as much as possible.

[0320] Figure 7 It is a block diagram of an electronic device according to an exemplary embodiment. Figure 7 The electronic device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0321] like Figure 7 As shown, the electronic device 700 includes a processor 701, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 702 or a program loaded from a memory 706 to a random access memory (RAM) 703. In the RAM 703, various programs and data required for the operation of the electronic device 700 are also stored. The processor 701, the ROM 702, and the RAM 703 are connected to each other via a bus 704. An input / output (I / O) interface 705 is also connected to the bus 704.

[0322] The following components are connected to the I / O interface 705: a memory 706 including a hard disk, etc.; and a communication part 707 including a network interface card such as a LAN (Local Area Network) card, a modem, etc., and the communication part 707 performs communication processing via a network such as the Internet; a drive 708 is also connected to the I / O interface 705 as needed.

[0323] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 707. When the computer program is executed by the processor 701, the above-mentioned functions defined in the method of the present application are executed.

[0324] In an exemplary embodiment, a storage medium including instructions is also provided, such as a memory including instructions, and the instructions can be executed by the processor 701 of the electronic device 700 to complete the above method. Optionally, the storage medium can be a non-transitory computer-readable storage medium, for example, the non-transitory computer-readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0325] In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, apparatus, or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0326] Figure 8 The present invention is a structural block diagram of an electronic device according to an exemplary embodiment. Figure 8 The electronic device shown is only an example and should not limit the functions and scope of use of the embodiments of the present application. Figure 8As shown, the electronic device 800 includes a processor 801 and a memory 802. The memory 802 is used to store program codes, and the processor 801 is connected to the memory 802 and is used to read the program codes from the memory 802 to implement the wind speed representative year correction method in the above embodiment.

[0327] Optionally, the number of processors 801 may be one or more.

[0328] Optionally, the electronic device may further include an interface 803, and the number of the interface 803 may be multiple. The interface 803 may be connected to an application program and may receive data from an external device such as a sensor.

[0329] An embodiment of the present application also proposes a non-temporary computer-readable storage medium. When the instructions in the storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute the stress- and life-based joint control method of the deep peak-shaving steam turbine in the above-mentioned embodiment.

[0330] An embodiment of the present application also proposes a computer program product, including a computer program, which, when executed by a processor in a communication device, implements the stress- and life-based joint control method of the deep peak-shaving steam turbine in the above embodiment.

[0331] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed in this application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0332] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A closed-loop control method for a deep peak-shaving steam turbine based on relative stress margin, characterized in that: include: Obtaining a first equivalent stress of a high-temperature key component of a deep peak-shaving steam turbine, and obtaining an absolute value of the first equivalent stress, wherein the first equivalent stress has positive and negative properties; Obtaining the material allowable limit stress of the high-temperature key component; Obtaining a difference between an absolute value of the first equivalent stress and an allowable limit stress of the material, and determining a relative stress margin of the high-temperature key component according to the difference and the absolute value of the first equivalent stress; performing closed-loop control on the speed and load of the steam turbine under target operating conditions according to the relative stress margin of the high-temperature key components; The obtaining of the allowable limit stress of the material of the high-temperature key component comprises: Determine the material yield limit of the high temperature key component and the material endurance strength of the high temperature key component with a creep rupture time of a set time; Determine, according to the material yield limit of the high-temperature key component and the material endurance strength, a first material allowable limit stress when the operating temperature is greater than or equal to the material creep limit temperature, and a second material allowable limit stress when the operating temperature is less than the material creep limit temperature; According to the current operating temperature of the steam turbine, the material allowable limit stress of the high-temperature key component is determined from the first material allowable limit stress and the second material allowable limit stress.

2. The method according to claim 1, characterized in that The step of determining the material allowable limit stress of the high-temperature key component from the first material allowable limit stress and the second material allowable limit stress according to the current operating temperature of the steam turbine comprises: Determining whether the current operating temperature is greater than or equal to the material creep limit temperature; If the current operating temperature is greater than or equal to the material creep limit temperature, determining the material allowable limit stress of the high-temperature key component to be the first material allowable limit stress; If the current operating temperature is lower than the material creep limit temperature, the material allowable limit stress of the high-temperature key component is determined to be the second material allowable limit stress.

3. The method according to claim 2, characterized in that The process of determining the allowable limit stress of the first material includes: Determine a minimum value from the material yield limit of the high-temperature key component and the material endurance strength, and determine the minimum value as the first material allowable limit stress; Wherein, the allowable limit stress of the second material is the material yield limit of the high-temperature key component.

4. The method according to any one of claims 1 to 3, characterized in that The controlling of the speed and load of the steam turbine under target operating conditions according to the relative stress margin of the high-temperature key components includes: Comparing the relative stress margins of each of the high-temperature key components, and determining a minimum value therefrom as the minimum relative stress margin of the steam turbine; The rotation speed and load under the target working condition are controlled according to the minimum relative stress margin.

5. The method according to claim 4, characterized in that The controlling the rotation speed and load under the target working condition according to the minimum relative stress margin includes: According to the minimum stress safety multiple, determine the correction coefficient corresponding to the speed change rate and load change rate; Obtaining a product of the correction coefficient and a speed change rate setting value as the speed change rate of the speed, and controlling the speed under the target working condition according to the speed change rate; The product of the correction coefficient and the load change rate setting value is obtained as the load change rate of the load, and the load under the target working condition is controlled according to the speed change rate.

6. The method according to claim 5, characterized in that The method further comprises: If the minimum stress safety multiple is within the emergency shutdown range, the steam turbine is controlled to perform an emergency shutdown operation after a set time.

7. A closed-loop control device for a deep peak-shaving steam turbine based on relative stress margin, characterized in that: include: A first acquisition module is used to acquire a first equivalent stress of a high-temperature key component of a deep peak-shaving steam turbine, and to acquire an absolute value of the first equivalent stress, wherein the first equivalent stress has positive and negative properties; A second acquisition module is used to obtain the allowable limit stress of the material of the high-temperature key component; A third acquisition module is used to obtain the difference between the absolute value of the first equivalent stress and the allowable limit stress of the material, and determine the relative stress margin of the high-temperature key component according to the difference and the absolute value of the first equivalent stress; A control module, used for performing closed-loop control of the speed and load of the steam turbine under target operating conditions according to the relative stress margin of the high-temperature key components; The second acquisition module is further used for: Determine the material yield limit of the high temperature key component and the material endurance strength of the high temperature key component with a creep rupture time of a set time; Determine, according to the material yield limit of the high-temperature key component and the material endurance strength, a first material allowable limit stress when the operating temperature is greater than or equal to the material creep limit temperature, and a second material allowable limit stress when the operating temperature is less than the material creep limit temperature; According to the current operating temperature of the steam turbine, the material allowable limit stress of the high-temperature key component is determined from the first material allowable limit stress and the second material allowable limit stress.

8. The device according to claim 7, characterized in that The second acquisition module is further used for: Determining whether the current operating temperature is greater than or equal to the material creep limit temperature; If the current operating temperature is greater than or equal to the material creep limit temperature, determining the material allowable limit stress of the high-temperature key component to be the first material allowable limit stress; If the current operating temperature is lower than the material creep limit temperature, the material allowable limit stress of the high-temperature key component is determined to be the second material allowable limit stress.

9. The device according to claim 7, characterized in that The second acquisition module is further used for: Determine a minimum value from the material yield limit of the high-temperature key component and the material endurance strength, and determine the minimum value as the first material allowable limit stress; Wherein, the allowable limit stress of the second material is the material yield limit of the high-temperature key component.

10. The device according to any one of claims 7 to 9, characterized in that: The control module is also used for: Comparing the relative stress margins of each of the high-temperature key components, and determining a minimum value therefrom as the minimum relative stress margin of the steam turbine; The rotation speed and load under the target working condition are controlled according to the minimum relative stress margin.

11. The device according to claim 10, characterized in that The control module is also used for: According to the minimum stress safety multiple, determine the correction coefficient corresponding to the speed change rate and load change rate; Obtaining a product of the correction coefficient and a speed change rate setting value as the speed change rate of the speed, and controlling the speed under the target working condition according to the speed change rate; The product of the correction coefficient and the load change rate setting value is obtained as the load change rate of the load, and the load under the target working condition is controlled according to the speed change rate.

12. The device according to claim 11, characterized in that The control module is also used for: If the minimum stress safety multiple is within the emergency shutdown range, the steam turbine is controlled to perform an emergency shutdown operation after a set time.

13. An electronic device, characterized in that: include: one or more processors; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the method according to any one of claims 1 to 6. 14 . A non-transitory computer-readable storage medium, when instructions in the storage medium are executed by a processor of an electronic device, the electronic device is enabled to perform the method as claimed in claim 1 .

15. A computer program product, comprising a computer program, which, when executed by a processor in a communication device, implements the method according to any one of claims 1 to 6.

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