Marine nuclear turboset dynamic simulation method considering in-stage loss

Abstract

The invention discloses a marine nuclear steam turbine unit dynamic simulation method considering in-stage loss, and belongs to the field of marine nuclear steam turbine stage unit dynamic simulation computation.The marine nuclear steam turbine unit dynamic simulation method comprises the steps that turbine structure parameters and boundary conditions are input, a static model is built, and initial parameters are obtained; constructing a dynamic model, and performing calculation based on the structure parameters and the initial parameters to obtain a calculation result; and advancing the time step length based on the calculation result, and carrying out variable working condition calculation according to the input variable operation parameters to realize dynamic simulation calculation of the marine nuclear steam turbine unit. According to the method, the initial parameters of dynamic simulation can be obtained according to the structure parameters and the boundary conditions, detailed parameters of steam extraction at all levels do not need to be provided as the initial parameters of initial dynamic calculation, numerical instability caused by large parameter changes in the initial stage is avoided, the dynamic model is improved in combination with the static model, and the dynamic simulation efficiency is improved. The in-stage loss during dynamic calculation is considered, and the calculation accuracy is improved.

Description

Technical Field

[0001] The present invention belongs to the field of dynamic simulation calculation of marine nuclear steam turbine stages, and particularly relates to a dynamic simulation method for marine nuclear steam turbine units considering internal stage losses. Background Art

[0002] Compared with large steam turbines for power generation in thermal power plants and nuclear power plants, the initial parameters of small nuclear power steam turbines used in ships are relatively low, usually in a saturated state or a low superheat state. Moreover, marine steam turbines need to have greater maneuverability, that is, the operating conditions of the steam turbine change over a large range and at a high frequency, and the rotational speed is variable, which puts forward higher requirements for the simulation accuracy of the steam turbine. With the breakthrough of small modular reactor technology, permanent magnet generator technology, and electric propulsion technology, marine nuclear steam turbines are shifting from propulsion functions to power generation functions. Traditional steam turbine simulation models usually select and output steam turbine parameters according to parameter diagrams fitted by a large number of experiments in order to achieve real-time simulation of the ship's secondary loop system, and cannot show the variation law of steam turbine parameters during variable operating conditions.

[0003] In traditional steam turbine dynamic simulation methods, the lumped parameter method is generally used to regard the steam turbine as a zero-dimensional component and simply simulate the steam turbine, which will produce large errors outside the preset operating condition range and it is difficult to guarantee the prediction ability. A more refined model simulates the steam turbine based on the conservation of mass, energy, and momentum, but the model is based on an ideal volume assumption, ignoring many effects caused by the mechanism process of steam flow, and requires the extraction parameters of each stage. If suitable initial volume parameters are lacking, the simulation will diverge, reducing the accuracy and simplicity of the simulation. Therefore, the current simulation methods lack the calculation and analysis of the influence of the mechanism process, and the lack of extraction parameters in marine nuclear power steam turbines puts higher requirements on the simulation method. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a dynamic simulation method for marine nuclear steam turbine units considering internal stage losses, including:

[0005] Obtain the steam turbine structure parameters and boundary conditions, construct a static model based on the steam turbine structure parameters and boundary conditions, and obtain the initial parameters of the static model;

[0006] Based on the initial parameters, construct a dynamic model and perform calculations to obtain calculation results;

[0007] Advance the time step based on the calculation results, and perform variable operating condition calculations according to the input variable operating parameters to achieve dynamic simulation calculation of marine nuclear steam turbine units.

[0008] Preferably, the process of constructing the static model includes: dividing the volume according to the steam turbine structure and numbering it, and connecting based on the supercritical correction module, cascade calculation module, supersaturation correction module, loss calculation module, velocity calculation module, and reference point calculation module to complete the construction of the static model and obtain the initial parameters.

[0009] Preferably, the losses calculated by the loss calculation module include but are not limited to: incidence loss, height loss, impeller friction loss, leakage loss, residual velocity loss, supersaturation loss, condensation loss, primary droplet entrainment loss, vapor friction loss, centrifugal loss, braking loss, and deposition loss.

[0010] Preferably, the supersaturation correction module is used to calculate the Wilson point humidity at the outlet of each cascade according to the Wilson point calculation method, and compare it with the actual humidity at the outlet of each stage cascade to determine whether the steam state is in an equilibrium state, superheated state, or supersaturated state; according to the volume type and steam state, limit the loss types in the loss calculation module.

[0011] Preferably, the process of obtaining the calculation result includes:

[0012] Input the parameters at this moment according to the initial parameters obtained from the static model, including boundary conditions, pressures of each volume, enthalpies, entropies, dryness fractions, and specific volume parameters at the inlets and outlets of each volume;

[0013] According to the parameters at this moment, calculate the mass flowing out of each volume to obtain the mass change, and perform conservation calculation to obtain the pressures of each volume and the enthalpy values at the inlets of each volume;

[0014] Calculate the specific volume according to the mass of each volume combined with the volume, and calculate the absolute velocity and relative velocity of each volume according to the continuity equation;

[0015] According to the supersaturation correction model and the loss calculation model, calculate the enthalpy difference at the inlets and outlets of each volume to obtain the enthalpy values at the outlets of each volume, and according to the physical properties of water vapor, obtain entropy, dryness fraction, stagnation pressure, and stagnation specific volume parameters from pressure, enthalpy, and velocity;

[0016] Calculate the power and efficiency of the steam turbine according to the Euler turbine equation and the loss model.

[0017] Preferably, the conservation calculation includes mass conservation calculation and energy conservation calculation;

[0018] The mass conservation calculation includes: calculating the inlet and outlet mass flows of each volume according to the thermodynamic parameters and velocity coefficients of the cascade channel, obtaining the mass change in the volume, combining with the mass conservation formula to obtain the first-order linear ordinary differential equation of each volume with respect to pressure, and using the improved Euler method for numerical solution to obtain the pressure of the volume at the next moment;

[0019] The energy conservation calculation includes: dividing the volume into an inlet surface and an outlet surface, obtaining the enthalpy difference between the inlet and outlet of the volume according to the volume position and the loss module, performing energy conservation calculation on the enthalpy value at the inlet of the volume to obtain a first-order linear ordinary differential equation of the enthalpy value at the inlet of each volume, using the first-order Euler method for numerical solution to obtain the enthalpy value at the inlet of the volume at the next moment, and combining the enthalpy difference between the inlet and outlet of the volume to obtain the enthalpy value at the outlet of each volume.

[0020] Preferably, the process of advancing the time step based on the calculation result and performing off-design calculation according to the input variable operating parameters includes: changing the enthalpy value and speed at the inlet at the next moment according to the variable operating parameters input in real time, including the inlet pressure, enthalpy value, and speed of the steam turbine, to achieve off-design calculation.

[0021] On the other hand, the present invention also provides an electronic device, including a memory, a processor, and a calculation program stored in the memory and executable on the processor. When the processor executes the calculation program, the method is implemented.

[0022] On the other hand, the present invention also provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the method is implemented.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] The present invention can obtain the initial parameters of dynamic simulation according to the structural parameters and boundary conditions, without the need to provide detailed parameters of each stage of extraction steam as the initial parameters of initial dynamic calculation, avoiding numerical instability caused by large parameter changes in the initial stage, and improving the dynamic model by combining with the static model, considering the in-stage loss during dynamic calculation, improving the calculation accuracy, and being able to calculate the parameter changes of the unit under operating conditions involving flow rate and speed, meeting the application requirements of steam turbines in different periods. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0026] Figure 1 is the single-stage flow chart of the static model of the embodiment of the present invention;

[0027] Figure 2 is the schematic diagram of single-stage volume numbering of the embodiment of the present invention;

[0028] Figure 3 is the whole-machine flow chart of the static model of the embodiment of the present invention;

[0029] Figure 4 This is the dynamic model flow chart of the embodiment of the present invention. Specific embodiments

[0030] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0031] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0032] Embodiment 1

[0033] As Figure 1 and Figure 4 shown, a dynamic simulation method for a marine nuclear steam turbine unit considering internal losses in this embodiment is provided, including:

[0034] Step 1: Input the structural parameters and boundary conditions of the steam turbine, construct a static model and obtain initial parameters;

[0035] Step 2: Construct a dynamic model and perform calculations based on the structural parameters and initial parameters to obtain calculation results;

[0036] Step 3: Advance the time step based on the calculation results and perform off-design calculations according to the input variable operating parameters to achieve the dynamic simulation calculation of the marine nuclear steam turbine unit.

[0037] The steam turbine described in Step 1 is a single-cylinder condensing steam turbine, and each stage is a full-arc admission pressure stage. Under off-design conditions, only the opening of the admission valve is changed to control the flow rate, the rotational speed is the input condition, and no extraction and steam-water separation devices are provided;

[0038] The input structural parameters of the steam turbine described in Step 1 include the number of stages of the steam turbine, the outlet angle of the stator blades of each stage, the outlet angle of the rotor blades, the outlet area of the stator blades, the outlet area of the rotor blades, the volume of the stator blades, the volume of the rotor blades, the height of the stator blades, the height of the rotor blades, and the root diameter of the rotor blades;

[0039] The boundary conditions include: the rotational speed of the stage group; the pressure, flow rate, and enthalpy at the inlet; and the pressure at the outlet of the stage group.

[0040] The construction of the static model and obtaining the initial parameters described in Step 1 include the following steps:

[0041] Connect each module according to the single-stage structure, including a supercritical correction module, a cascade module, an oversaturation correction module, a loss calculation module, a velocity calculation module, and a reference point calculation module. The single-stage connection relationship is as Figure 1as shown

[0042] The losses within the stage include 1. incidence loss, 2. height loss, 3. impeller friction loss, 4. leakage loss, 5. residual velocity loss, 6. supersaturation loss, 7. condensation loss, 8. primary droplet entrainment loss, 9. vapor friction loss, 10. centrifugal loss, 11. braking loss, 12. deposition loss. A value needs to be assumed for each loss at the beginning of the single-stage calculation. Items 1-5 can be set to 1.0 kJ / kg, and items 6-12 can be set to 0 kJ / kg.

[0043] Supercritical module: Judge the flow velocity at the exit of the cascade. If it is supersonic, use the supercritical algorithm to correct the velocity; if it is not supersonic, use the subcritical algorithm. Cascade calculation module: Use the cascade calculation module twice after the supercritical correction module. First, calculate the moving blade cascade, and then calculate the stationary blade cascade. The relative velocity is used for the moving blade cascade, and the absolute velocity is used for the stationary blade cascade.

[0044] Supersaturation correction module: Judge the steam state. If the humidity at the exit of the cascade is greater than 0 and greater than the Wilson point humidity, it is considered to be in an equilibrium state; if the humidity at the exit of the cascade is greater than 0 but less than the Wilson point humidity, it is considered to be in a supersaturated state; if the humidity at the exit of the cascade is equal to 0, it is considered to be in a superheated state.

[0045] Loss calculation module: Calculate each loss. When in the equilibrium state, all losses except the supersaturation loss are greater than 0; when in the supersaturated state, losses 1-6 are greater than 0, and the rest are 0; when in the superheated state, losses 1-5 are greater than 0, and the rest are 0.

[0046] Judge each loss. If the sum of the absolute errors of each loss is less than 3.0 kJ / kg, the calculation of this stage is completed, and the calculation of the upstream stage is carried out; if it is greater than 3.0 kJ / kg, replace the assumed value of the loss calculation with the calculated value and recalculate.

[0047] Connect each stage according to the number of turbine stages and carry out volume numbering. The single-stage volume includes the volume before the stationary blade and the volume before the moving blade. The single-stage volume numbering is as Figure 2 shown. The volume is divided into the volume before the stationary blade and the volume before the moving blade. The volume numbers of the stationary blade and the moving blade before the i-th stage are (i, 1) and (i, 2). The overall connection relationship is as Figure 3 shown. Start the calculation from the last stage of the turbine. Assume that the exhaust enthalpy value is 2000.0 kJ / kg. After completing the single-stage calculation, carry out the calculation of the upstream stage until the calculation of the first stage is completed. In the single-stage calculation, the velocity before the cascade is missing and needs to be assumed. Set the velocity before the cascade to half of the velocity after the cascade;

[0048] Input the structural parameters and boundary conditions;

[0049] Set accounting conditions and obtain the initial parameters of the dynamic model based on the static model.

[0050] After completing all-stage calculations, first check the velocity. The inlet velocity of the first-stage stator vane is set at a fixed value of 30 m / s. Sum the absolute values of the differences between the inlet velocities of all vanes and the outlet velocities of the upstream vanes to obtain the total velocity error. When the error is less than the number of stages, the velocity check is completed. For example, for a 12-stage steam turbine, the total velocity error is less than 12 m / s. When the error is greater than the number of stages, replace the original vane inlet velocity with the upstream vane outlet velocity and recalculate;

[0051] Secondly, check the enthalpy value. When the absolute value of the error between the enthalpy value at the inlet of the first-stage stator vane and the inlet enthalpy value in the stage group boundary conditions is less than 3.0 kJ / kg, the enthalpy check is completed. If the error does not meet the requirement, change the assumed exhaust enthalpy value. Specifically, if the error is greater than 3.0 kJ / kg, decrease the exhaust enthalpy by 1.0 kJ / kg and recalculate; if the error is less than -3.0 kJ / kg, increase the exhaust enthalpy by 1.0 kJ / kg and recalculate;

[0052] Finally, check the pressure. When the absolute value of the relative error between the pressure at the inlet of the first-stage stator vane and the inlet pressure in the stage group boundary conditions is less than 2‰, the pressure check is completed. If the error does not meet the requirement, change the specific volume of each stage. Specifically, if the relative error is greater than 2‰, decrease the specific volume of each stage by 1‰ and recalculate; if the relative error is less than -2‰, increase the specific volume of each stage by 1‰ and recalculate.

[0053] After all accounting modules meet the requirements, the static model calculation is completed, and the initial parameters of the dynamic model are obtained, including the enthalpy values h, absolute velocities c, relative velocities w, angles α, β, entropy values s, specific volumes ν, pressures p of each volume, and the rotational speed of the stage group at the inlet and outlet of each volume.

[0054] The construction of the dynamic model described in step 2 includes the following steps:

[0055] Calculate the outflow mass flow of each volume based on the parameters of each volume at this moment to obtain the mass change;

[0056] The calculation formula for the outflow mass flow of the volume is:

[0057] According to the steady-state energy conservation equation, at the inlet and outlet of the vane under isentropic conditions, it satisfies:

[0058]

[0059] Among them, is the stagnation enthalpy value at the vane inlet, h in is the enthalpy value at the vane inlet, c in is the velocity at the vane inlet, h out,s is the isentropic enthalpy value at the vane outlet,

[0060] The steam state in the isentropic process satisfies:

[0061]

[0062] Among them, c p is the specific heat capacity at constant pressure, T is the temperature, κ is the isentropic exponent, R is the gas constant, p is the pressure, and v is the specific volume.

[0063] The isentropic process of an ideal gas can be written as:

[0064] pv κ = C;

[0065] where C is a constant

[0066] Then:

[0067]

[0068] where the actual outlet pressure p out is equal to the outlet pressure p out,s

[0069] Then the ideal velocity c out,s at the cascade outlet can be written as:

[0070]

[0071] Also, since

[0072]

[0073] Then, the ideal flow rate G s of the cascade can be written as

[0074]

[0075] where is the pressure ratio

[0076] Considering that in the actual process, non-isentropy will cause the velocity to not reach the ideal velocity, using the velocity coefficient to represent the actual velocity

[0077] the actual flow rate is expressed as

[0078]

[0079] Therefore, for the volume numbered (i,1), the outflow flow rate can be written as:

[0080]

[0081] where G is the mass flow rate; is the cascade velocity coefficient; ν is the specific volume; A is the cascade outlet area; ε is the pressure ratio; κ is the adiabatic exponent.

[0082] For all the symbols in the text, in the superscript or subscript, * represents the stagnation state; in and out represent the volumetric inlet and outlet; i,1 and i,2 are the volumetric numbers, and i is the stage number; s represents the isentropic ideal state. For simplicity of expression, only the volume before the stator blade is described subsequently, and the volume before the rotor blade is the same.

[0083] ν 理想 = ν(p i，1 ,s i-1,2 );

[0084] In the formula, v() represents the specific volume obtained from p and s according to the IAPWS-IF97 water vapor property library.

[0085] Perform mass conservation calculations based on the mass change to obtain the pressures of each volume at the next moment. Calculate the absolute velocity and relative velocity of each volume according to the continuity equation, and combine with the Euler turbine equation to calculate the wheel work;

[0086] Calculate the enthalpy at the inlet of each volume at the next moment according to the energy conservation equation, and obtain parameters such as entropy and dryness from the property library;

[0087] Obtain the enthalpy values at the outlets of each volume according to the enthalpy difference between the inlet and outlet of the volume calculated by the loss module, and obtain parameters such as entropy s, dryness x, stagnation pressure p * , stagnation specific volume ν * and other parameters, and combine with the loss module to calculate the output work of the steam turbine at the next moment.

[0088] Advance the time step and repeat the above steps.

[0089] Loss module: In the order of loss types, the 12 losses are as follows

[0090]

[0091]

[0092] In the formula: β is the outlet relative steam flow angle; α is the outlet absolute steam flow angle; θ is the incidence angle.

[0093]

[0094] In the formula, C1 is the blade height coefficient; l is the cascade height; Δh i is the effective enthalpy drop in the wheel circumference of the i-th stage.

[0095]

[0096] In the formula, is the enthalpy obtained from the property library according to pressure and entropy;

[0097]

[0098] Wherein, C2 is the impeller friction loss coefficient; di is the average diameter of the cascade.

[0099] Δh4 = C3(Δh i -Δh2);

[0100] Wherein, C3 is the steam leakage coefficient.

[0101]

[0102] Wherein, μc is the residual velocity loss coefficient.

[0103]

[0104] Wherein, n is the polytropic index.

[0105]

[0106] Wherein, hfg is the latent heat of condensation, Y is the humidity, and C4 is the condensation loss coefficient.

[0107]

[0108] Wherein E0 is the ideal enthalpy drop

[0109]

[0110] Wherein, Ω is the degree of reaction.

[0111]

[0112] Wherein, δ is the dimensionless momentum thickness.

[0113]

[0114] Wherein, b and c are the moving blade water droplet deposition coefficient and the centrifugal migration coefficient; r i is the average radius of the i-th stage cascade, and the subscript tip represents the parameter at the blade tip. For a typical low-pressure steam turbine is 0.70.

[0115]

[0116] Wherein, a is the stationary blade water droplet deposition coefficient; w' i,2 represents the relative velocity of the droplet

[0117]

[0118] The total volume losses calculated according to the loss module are the enthalpy differences at the inlet and outlet of the volume, and the enthalpy at the outlet of the volume can be obtained

[0119]

[0120] The mass conservation calculation described in step B above includes:

[0121] B1. List the inflow and outflow masses for each volume;

[0122]

[0123] where t is time; M is the mass of steam in the volume.

[0124] B2. Decompose and simplify the mass conservation equation to obtain a first-order linear ordinary differential equation for the pressure change rate of each volume;

[0125] The decomposed and simplified mass conservation equation is transformed into a pressure change rate equation as:

[0126]

[0127] where V is the volume of the volume. The above equation is also expressed as

[0128] B3. Use the improved Euler method to handle the first-order linear ordinary differential equation for pressure to obtain the pressure at time t+dt.

[0129] The improved Euler method includes:

[0130]

[0131] where the superscript t is the value at this moment, and t+dt is the value at the next moment; represents the predicted value of the pressure at the next moment of the volume obtained according to the explicit Euler method; is the corrected value of the pressure at the next moment of the volume. The improved Euler method can effectively improve the stability of numerical calculations.

[0132] Calculate the absolute velocity and relative velocity of each volume according to the continuity equation and calculate the wheel circumference work in combination with the Euler turbine equation. At time t, it is:

[0133]

[0134] The formula for calculating the wheel circumference work is:

[0135]

[0136] where W_h is the wheel circumference work

[0137] The output work W of the steam turbine

[0138]

[0139] The energy conservation calculation described in step C above includes:

[0140] C1. Decompose the energy conservation equation and simplify it to obtain a first-order linear ordinary differential equation for the change rate of the enthalpy value at the inlet of each volume;

[0141] The decomposed and simplified energy conservation equation is transformed into an enthalpy change rate equation as:

[0142]

[0143] C2. Use the explicit Euler method to handle the first-order linear ordinary differential equation for the enthalpy value at the inlet of the volume to obtain the enthalpy values of each volume at the next moment.

[0144]

[0145] In the above step D, obtaining the enthalpy value at the outlet of each volume according to the loss calculation module and calculating the output work at the next moment includes the following steps:

[0146] D1. Judge the volume type, limit the loss calculation type, calculate different losses. If it is the volume before the stator blade, calculate losses 2 - 12; if it is the volume before the rotor blade, calculate losses 1, 4, 6 - 9, 12;

[0147] D2. Obtain the volume state according to the supersaturation correction module, limit the loss calculation type. When in the equilibrium state, except for the supersaturation loss being 0, other losses are greater than 0; when in the supersaturated state, losses 1 - 6 are greater than 0, and the rest are 0; when in the superheated state, losses 1 - 5 are greater than 0, and the rest are 0. Calculate each loss according to the loss module to obtain the enthalpy value at the outlet of each volume

[0148] D3. Obtain other parameters from the property library as:

[0149]

[0150] D4. Calculate the output work and efficiency as:

[0151]

[0152] In the formula, η is the efficiency.

[0153] The variable operating parameters described in step 3 include the turbine inlet pressure, enthalpy value, and rotational speed, which are provided in real time by other equipment and used as the input parameters of the turbine. Change the inlet enthalpy value and rotational speed at the next moment according to the real-time input variable operating parameters to achieve off-design calculation. After each time step of the off-design calculation is completed, change the enthalpy value at the inlet of the first stage at the start of the next time step and u i = Nπd i , where N is the rotational speed.

[0154] On the other hand, this embodiment also provides an electronic device, including a memory, a processor, and a computing program stored in the memory and executable on the processor. When the processor executes the computing program, the method is implemented.

[0155] On the other hand, this embodiment also provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the method is implemented.

[0156] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A dynamic simulation method for marine nuclear steam turbine units considering internal losses, characterized in that Including: Obtain the structural parameters and boundary conditions of the steam turbine, construct a static model based on the structural parameters and boundary conditions of the steam turbine, and obtain the initial parameters of the static model; Based on the initial parameters, construct a dynamic model and perform calculations to obtain calculation results; Advance the time step based on the calculation results, and perform off-design calculations according to the input variable operating parameters to achieve dynamic simulation calculations of marine nuclear steam turbine units.

2. The method according to claim 1, wherein The process of constructing the static model includes: dividing the volume according to the steam turbine structure and numbering, and connecting based on the supercritical correction module, cascade calculation module, supersaturation correction module, loss calculation module, velocity calculation module, and reference point calculation module to complete the construction of the static model and obtain the initial parameters.

3. The method according to claim 2, characterized in that The losses calculated by the loss calculation module include but are not limited to: incidence loss, tip loss, disk friction loss, leakage loss, residual velocity loss, supersaturation loss, condensation loss, primary droplet entrainment loss, vapor friction loss, centrifugal loss, braking loss, and deposition loss.

4. The method according to claim 2, wherein The supersaturation correction module is used to calculate the Wilson point humidity at the outlet of each cascade according to the Wilson point calculation method, compare it with the actual humidity at the outlet of each stage of the cascade, and determine whether the steam state is an equilibrium state, a superheated state, or a supersaturated state; according to the volume type and steam state, restrict the loss types in the loss calculation module.

5. The method according to claim 1, wherein The process of obtaining the calculation results includes: According to the initial parameters obtained from the static model, input the parameters at this moment, including boundary conditions, pressures of each volume, enthalpies, entropies, dryness, and specific volume parameters at the inlet and outlet of each volume; According to the parameters at this moment, calculate the mass flowing out of each volume, obtain the mass change, and perform conservation calculations to obtain the pressures of each volume and the enthalpy values at the inlets of each volume; Obtain the specific volume according to the mass of each volume combined with the volume, and calculate the absolute velocity and relative velocity of each volume according to the continuity equation; According to the supersaturation correction model and the loss calculation model, calculate the enthalpy difference at the inlet and outlet of each volume to obtain the enthalpy value at the outlet of each volume, and according to the physical properties of water vapor, obtain entropy, dryness, stagnation pressure, and stagnation specific volume parameters from pressure, enthalpy, and velocity; Calculate the power and efficiency of the steam turbine according to the Euler turbine equation and the loss model.

6. The method according to claim 5, wherein The conservation calculations include mass conservation calculations and energy conservation calculations; The mass conservation calculation includes: calculating the inlet and outlet mass flow rates of each volume according to the thermodynamic parameters and velocity coefficients of the cascade passage, obtaining the mass change in the volume, combining with the mass conservation formula to obtain a first-order linear ordinary differential equation of each volume with respect to pressure, and using the improved Euler method for numerical solution to obtain the pressure of the volume at the next moment; The energy conservation calculation includes: dividing the volume into an inlet surface and an outlet surface, obtaining the enthalpy difference between the inlet and outlet of the volume according to the volume position and the loss module, performing energy conservation calculations on the enthalpy value at the inlet of the volume to obtain a first-order linear ordinary differential equation of each volume inlet with respect to the enthalpy value, using the first-order Euler method for numerical solution to obtain the enthalpy value at the inlet of the volume at the next moment, and combining the enthalpy difference between the inlet and outlet of the volume to obtain the enthalpy value at the outlet of each volume.

7. The method according to claim 1, characterized in that The process of advancing the time step based on the calculation result and performing off-design calculations according to the input variable operating parameters includes: changing the inlet enthalpy value and rotational speed at the next moment according to the variable operating parameters input in real time, including the inlet pressure, enthalpy value, and rotational speed of the steam turbine, to achieve off-design calculations.

8. An electronic device, comprising a memory, a processor, and a computing program stored in the memory and executable on the processor, characterized in that, When the processor executes the calculation program, it implements the method described in any one of claims 1-7.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method described in any one of claims 1-7.

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