Dynamic simulation method and device for primary frequency regulation based on thermal power condensate throttling strategy

Abstract

The present invention provides a method and device for dynamic simulation of primary frequency regulation based on a thermal power condensate throttling strategy, which is used to analyze the dynamic characteristics of the unit when the power plant executes the primary frequency regulation instruction through the condensate throttling strategy after a power disturbance occurs in the power grid. The dynamic characteristics mainly include the turbine governor system, the condensate pump frequency conversion system, the dynamic heat exchange characteristics between the low-pressure heater and the extraction steam, the flow characteristics of the extraction steam pipeline, and the output characteristics of the turbine body. The moving boundary method is mainly applied to the heat exchange process between the condensate (cold fluid) in the low-pressure heater and the shell-side extraction steam (hot fluid). The heat exchange process between the cold and hot fluids can be divided into the superheating stage, the phase change stage, and the subcooling stage according to the state of the extraction steam accumulation. The moving boundary method can be used in the turbine reheat system to more accurately obtain the dynamic variation law of the extraction steam temperature and pressure. The low-pressure side extraction steam pressure is the key to determining the low-pressure cylinder side extraction steam flow rate and the key to determining the instantaneous power increase of the turbine. The moving boundary method (MBM)-based dynamic frequency regulation of thermal power plant condensate throttling takes into account a comprehensive range of actual process factors and only considers one-dimensional modeling along the main axial flow direction, thus offering both fast and accurate simulation. This fast and accurate simulation method is a prerequisite for grid frequency security analysis. By understanding the dynamic response of power plant loads from when the frequency difference exceeds and returns to the dead zone, it provides a foundation for power plant primary frequency regulation control and grid frequency security analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a primary frequency regulation dynamic simulation method and device based on a thermal power condensate throttling strategy. Background Art

[0002] Thermal power units are positioned as regulating power sources and are the primary providers of multi-timescale regulation capabilities for the new power system. Primary frequency regulation is the process of restoring grid frequency by adjusting power generation output in the event of disturbances (load disturbances, generator power shortages, or renewable energy power fluctuations). Frequency control is fundamental to ensuring the safe and stable operation of the power system. Internal and external factors dictate the need for thermal power units to enhance their primary frequency regulation capabilities. The condensate throttling primary frequency regulation strategy is a method for enhancing the rapid load changes of thermal power units, thereby providing primary frequency regulation capabilities for the power grid. This strategy works by reducing the condensate flow rate entering each LP heater stage, thereby reducing the amount of steam extracted from the turbine stage into the LP heater. This effectively utilizes the turbine's thermal energy to rapidly increase turbine expansion work. There are two specific approaches: first, reducing the condensate pump frequency, which in turn reduces the flow rate into each LP heater stage. This increases the condensate outlet temperature and pressure at the LP heater, reducing the extraction flow rate into the LP heater. Second, if there are regulating valves on the extraction pipeline, the extraction flow rate can be directly reduced. However, most units' extraction pipelines only have on-off valves and lack flow regulation capabilities.

[0003] When condensate throttling is used for primary frequency regulation, both the power grid and power plants lack dynamic simulation methods to evaluate this process. The power grid needs to understand the primary frequency regulation capability under this strategy so that it can pre-determine the number of units participating in frequency regulation across the network for different disturbances. For primary frequency regulation simulation, the power system already has comprehensive transient simulation models for primary frequency regulation, including models for the governor system, boiler, and steam turbine of thermal power units, as well as the governor system and turbine of hydropower units. However, these models primarily utilize a high-pressure control valve primary frequency regulation strategy and do not account for the extraction steam between the turbine and the low-pressure heater, or the heat exchange between steam and condensate within the low-pressure heater. Therefore, to evaluate the primary frequency regulation capability under the condensate throttling strategy, a combined model of the turbine governor system, turbine, extraction steam piping, low-pressure heater, and deaerator is necessary.

[0004] Existing LP heater heat transfer processes have been considered in three-dimensional simulations of thermal systems in coal-fired power plants. However, modeling methods that consider distributed parameters in three-dimensional models require the gradual numerical solution of energy conservation, mass conservation, and momentum conservation equations at a large number of spatial nodes, resulting in slow simulations and unsuitable for power grid transient simulations. Therefore, one-dimensional modeling and solution should be considered. The one-dimensional heat transfer model for condensate throttling strategies primarily consists of partial differential equations. Due to the lack of a unified analytical solution for these equations, the commonly used characteristic curve method converts the partial differentials into a system of ordinary differential equations using functions of two independent variables. However, this places high demands on initial and boundary conditions. Numerical methods are often still required to solve the dynamic heat transfer process. The simulation accuracy of the steam and condensate heat transfer in the LP heater on a one-minute timescale directly determines the dynamic characteristics of the extraction flow reduction and, consequently, the dynamic processes of the turbine flow and power. The accuracy of primary frequency regulation significantly impacts high-precision power grid transient simulations. Therefore, in order to improve the dynamic characteristics of primary frequency regulation of thermal power plants when adopting the condensate throttling strategy, it is necessary to properly simplify the original partial differential equations and solve them using numerical methods.

[0005] Currently, mainstream simulation methods for the dynamic characteristics of heat exchangers fall into two categories. One treats the fluid undergoing phase change as a single entity, assuming the spatial state parameters of the entire heat exchange section are identical. However, since the heat transfer coefficient of the phase change section is much larger than that of the superheat and subcooling sections in reality, this lumped parameter approach suffers from significant errors and is difficult to accurately model. The second approach, the distributed parameter approach, considers temperature differences across spatial points. A more accurate approach involves dividing the heat exchange section into three segments: subcooling, two-phase, and superheat, and numerically solving each segment separately. However, this dense node division results in a long computational time, making the implicit formulation of the equations particularly difficult to solve. To address these issues, the present invention introduces the moving boundary method to the dynamic heat exchange simulation of thermal power plant condensate throttling and frequency modulation. The moving boundary method does not consider the differences in the spatial state parameters of the three segments after discretization. Instead, it treats each segment as a single entity, although the length of each segment varies over time. This method effectively accounts for the differences in heat transfer coefficients and the length variations of each segment, while retaining fewer unknowns than when the entire heat exchange section is discretized. This approach achieves both simulation accuracy and speed.

[0006] In summary, the existing technology has the problems of low simulation accuracy and slow simulation speed. Summary of the Invention

[0007] The present invention provides a method and device for dynamic simulation of primary frequency regulation based on thermal power condensate throttling strategy, which is used to solve the defects of low simulation accuracy and slow simulation speed in the prior art and realize high-precision and high-speed dynamic simulation of frequency regulation.

[0008] The present invention provides a primary frequency regulation dynamic simulation method based on a thermal power condensate throttling strategy, which is applied to a thermal power unit and includes:

[0009] According to the extraction steam aggregation state of the hot and cold fluid heat exchange process of the thermal power unit, a steam heat release model and a condensate heat absorption model are established along the flow direction of the hot and cold fluids using the moving boundary method; a thermal power unit simulation model is obtained based on a pre-constructed flow characteristic equation of the extraction steam pipeline, a pre-constructed turbine flow-power dynamic response equation, the steam heat release model, and the condensate heat absorption model;

[0010] In response to the voltage frequency difference exceeding the dead zone, a condensate flow rate step signal is obtained, and the condensate flow rate step signal is input into a pre-built thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment.

[0011] According to the present invention, a dynamic simulation method for primary frequency regulation based on a thermal power condensate throttling strategy is provided. The method uses a moving boundary method to establish a steam heat release model and a condensate heat absorption model along the flow direction of the cold and hot fluids according to the extraction steam aggregation state of the cold and hot fluids in the thermal power unit. The method specifically includes:

[0012] According to parameter changes of the cold and hot fluids along the flow direction during the heat exchange process, the heat exchange process is divided into a superheating section, a two-phase section, and a subcooling section, and the lengths of the superheating section, the two-phase section, and the subcooling section are set as time-dependent variables;

[0013] The energy conservation, mass conservation and physical property equations of steam heat release in the superheating section, two-phase section and subcooling section are constructed in sequence to obtain a steam heat release model; the energy conservation, mass conservation and physical property equations of condensate heat absorption in the superheating section, two-phase section and subcooling section are constructed in sequence to obtain a condensate heat absorption model.

[0014] According to a dynamic simulation method for primary frequency regulation based on a thermal power condensate throttling strategy provided by the present invention, the condensate flow rate step signal is input into a pre-built thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment, specifically comprising:

[0015] Obtaining initial parameters; wherein the initial parameters include the initial pressure of the extraction point, the initial temperature of the extraction point, the condensate inlet temperature, the condensate inlet pressure and the target load;

[0016] Inputting the initial parameters into the thermal power unit simulation model for solving to obtain steady-state parameters;

[0017] The steady-state parameters and the condensate flow rate step signal are input into the thermal power unit simulation model for iterative solution to obtain a dynamic value of the steam turbine power increment.

[0018] According to a primary frequency regulation dynamic simulation method based on a thermal power condensate throttling strategy provided by the present invention, the steady-state parameters and the condensate flow rate step signal are input into the thermal power unit simulation model for iterative solution to obtain a dynamic value of the turbine power increment, specifically comprising:

[0019] S1: inputting the steady-state parameters and the initial values ​​of the condensate flow rate step signal into the thermal power unit simulation model to obtain the parameter values ​​at the initial moment;

[0020] S2: Inputting the parameter values ​​at the initial moment into the simulation model of the thermal power unit to obtain a target iterative formula; the target iterative formula includes the turbine power iterative equations at the current moment and the previous moment;

[0021] S3: Set the turbine power at the current time step as an assumed value, solve the current equation according to the assumed value, substitute the solution result into the physical property equation of the subcooling section for verification, and if the equation is satisfied, record the assumed value and jump to step S4; if the equation is not satisfied, update the assumed value according to the preset power value iteration rule, and repeat step S3; wherein the current equation includes the steam heat release model and steam heat release model of the superheating section, the steam heat release model and steam heat release model of the two-phase section, and the mass conservation and energy conservation equations of the subcooling section;

[0022] S4: Increment the current time step by one, and repeat steps S3-S4 until the turbine power curve obtained according to the assumed value meets the preset end condition, and obtain the turbine power increment dynamic value according to the turbine power curve.

[0023] According to a primary frequency modulation dynamic simulation method based on a thermal power condensate throttling strategy provided by the present invention, the steam heat release model includes:

[0024] Overheating section:

[0025] in, is the average density of the superheat section, is the average flow rate in the superheat section, τ For time, x is the distance along the flow direction, is the average enthalpy value of the superheating section, is the average pressure of the superheat section, is the average heat transfer coefficient of the superheating section, is the average temperature of the superheat section, The average temperature of the condensate section corresponding to the two-phase extraction steam, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam, is the inlet density value of the superheating section, is the inlet value of the superheating section flow rate, is the inlet value of superheating section enthalpy, is the inlet pressure value of the superheat section, is the inlet temperature value of the superheat section;

[0026] Two-phase section:

[0027] in, is the average density of the two-phase segment, is the average flow velocity of the two-phase section, τ For time, x is the distance along the flow direction, is the average enthalpy value of the two-phase section, is the average pressure of the two-phase section, is the average heat transfer coefficient of the two-phase section, is the average temperature of the two-phase segment, is the average temperature of the condensate section corresponding to the extraction steam in the superheating section, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam, is the density of saturated steam, λ is the dryness, is the density of saturated water, is the saturated steam enthalpy;

[0028] Subcooling section:

[0029] in, is the average density of the supercooling section, is the average flow velocity in the supercooling section, τ For time, x is the distance along the flow direction, is the average enthalpy value of the supercooling section, is the average pressure of the supercooling section, is the average heat transfer coefficient of the subcooling section, is the average temperature of the supercooling section, is the average temperature of the condensate section corresponding to the extraction steam in the subcooling section, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam.

[0030] According to a primary frequency regulation dynamic simulation method based on a thermal power condensate throttling strategy provided by the present invention, the condensate heat absorption model includes:

[0031]

[0032] in, is the average density of condensate corresponding to each extraction section of subcooling, two-phase and superheating. is the average condensate flow rate corresponding to each extraction section of subcooling, two-phase and superheating, τ For time, x is the distance along the flow direction, is the average value of the condensate heat transfer coefficient corresponding to each section of extraction steam: subcooling, two-phase, and superheating. is the average condensate temperature corresponding to each extraction section of subcooling, two-phase and superheating. is the average specific heat capacity of condensate corresponding to each extraction section of subcooling, two-phase and superheating, is the average temperature of the two-phase segment, is the average temperature of the supercooling section, is the average temperature of the superheat section, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam.

[0033] The present invention also provides a primary frequency regulation dynamic simulation device based on a thermal power condensate throttling strategy, which is applied to a thermal power unit and includes:

[0034] A model unit is configured to establish a steam heat release model and a condensate heat absorption model along the flow direction of the cold and hot fluids according to the extraction steam aggregation state in the heat exchange process of the cold and hot fluids of the thermal power unit using a moving boundary method; and obtain a thermal power unit simulation model according to a pre-established flow characteristic equation of the extraction steam pipeline, a pre-established steam turbine flow-power dynamic response equation, the steam heat release model, and the condensate heat absorption model;

[0035] The simulation unit is used to obtain a condensate flow step signal in response to the voltage frequency difference exceeding the dead zone, input the condensate flow step signal into a pre-built thermal power unit simulation model for simulation calculation, and obtain a dynamic value of the turbine power increment.

[0036] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the program, a primary frequency regulation dynamic simulation method based on a thermal power condensate throttling strategy as described above is implemented.

[0037] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for dynamic simulation of primary frequency regulation based on thermal power condensate throttling strategy as described above is implemented.

[0038] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-described primary frequency regulation dynamic simulation methods based on thermal power condensate throttling strategies.

[0039] The present invention provides a method and device for dynamic simulation of primary frequency regulation based on a thermal power condensate throttling strategy. Based on the extraction steam aggregation state during the heat exchange process of the thermal power unit's hot and cold fluids, a steam heat release model and a condensate heat absorption model are established along the flow direction of the hot and cold fluids using the moving boundary method. A thermal power unit simulation model is obtained based on a pre-established flow characteristic equation for the extraction steam pipeline, a pre-established turbine flow-power dynamic response equation, the steam heat release model, and the condensate heat absorption model. In response to a voltage-frequency difference exceeding a dead zone, a condensate flow step signal is obtained, which is input into the pre-established thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment. The present invention utilizes the moving boundary method to model the dynamic heat exchange process of the thermal power unit, and only considers one-dimensional modeling along the axial main flow direction. This method combines the advantages of fast and accurate simulation, achieving high-precision and high-speed frequency regulation dynamic simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 This is one of the flow diagrams of the primary frequency regulation dynamic simulation method based on the thermal power condensate throttling strategy provided by the present invention;

[0042] Figure 2 This is the second flow chart of the primary frequency modulation dynamic simulation method based on the thermal power condensate throttling strategy provided by the present invention;

[0043] Figure 3 This is a structural diagram of a primary frequency modulation dynamic simulation device based on a thermal power condensate throttling strategy provided by the present invention;

[0044] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0046] The following combination Figure 1-Figure 2The present invention describes the dynamic simulation method of primary frequency regulation based on thermal power condensate throttling strategy, such as Figure 1 As shown, the method includes:

[0047] Step 110: Based on the extraction steam aggregation state during the heat exchange process of the cold and hot fluids of the thermal power unit, a steam heat release model and a condensate heat absorption model are established along the flow direction of the cold and hot fluids using the moving boundary method; a thermal power unit simulation model is obtained based on a pre-established flow characteristic equation of the extraction steam pipeline, a pre-established turbine flow-power dynamic response equation, the steam heat release model, and the condensate heat absorption model;

[0048] During the dynamic simulation of primary frequency regulation of a thermal power unit, the analysis of the unit's dynamic characteristics when the power plant executes primary frequency regulation instructions using a condensate throttling strategy after a power grid power disturbance is a key focus. These dynamic characteristics primarily include the turbine governor system, the condensate pump frequency conversion system, the dynamic heat exchange characteristics between the low-pressure heater and extraction steam, the flow characteristics of the extraction steam piping, and the turbine output characteristics.

[0049] In other words, the construction of a simulation model requires consideration of the dynamic characteristics described above. This paper utilizes the moving boundary method to construct a steam heat release model and a condensate heat absorption model based on the dynamic heat exchange characteristics of the low-pressure heater and extraction steam. This model, combined with the turbine flow-power dynamic response equation and the extraction steam piping flow characteristic equation, yields a thermal power unit simulation model. This resulting thermal power unit simulation model simultaneously accounts for the entire process: the governor system, the condensate pump, the three-stage heat exchange between condensate and steam, the extraction steam flow rate variations, and the turbine power dynamics.

[0050] It should be noted that in this embodiment of the present invention, the moving boundary method is primarily used to model the heat exchange process between condensate (cold fluid) and shell-side extraction steam (hot fluid) in the low-pressure heater. Specifically, the moving boundary method is applied to the modeling of the steam turbine reheat system, allowing for relatively accurate dynamic variations in extraction steam temperature and pressure. It is understood that the low-pressure heater-side extraction steam pressure is crucial for determining the low-pressure cylinder-side extraction steam flow rate and the instantaneous power increase of the steam turbine. Accurately modeling the dynamic variations in extraction steam temperature and pressure provides a solid foundation for power plant primary frequency regulation control and grid frequency security analysis.

[0051] In actual operation, the thermal power plant simulation model includes the flow characteristic equation for the extraction steam piping, the turbine flow-power dynamic response equation, a steam heat release model, and a condensate heat absorption model. These models are constructed along the flow direction of the hot and cold fluids using the moving boundary method, based on the extraction steam aggregation state during the heat exchange process.

[0052] In some embodiments, according to the extraction steam aggregation state of the hot and cold fluids in the thermal power unit heat exchange process, a steam heat release model and a condensate heat absorption model are established along the flow direction of the hot and cold fluids using the moving boundary method, specifically including:

[0053] According to parameter changes of the cold and hot fluids along the flow direction during the heat exchange process, the heat exchange process is divided into a superheating section, a two-phase section, and a subcooling section, and the lengths of the superheating section, the two-phase section, and the subcooling section are set as time-dependent variables;

[0054] The energy conservation, mass conservation and physical property equations of steam heat release in the superheating section, two-phase section and subcooling section are constructed in sequence to obtain a steam heat release model; the energy conservation, mass conservation and physical property equations of condensate heat absorption in the superheating section, two-phase section and subcooling section are constructed in sequence to obtain a condensate heat absorption model.

[0055] Specifically, it's important to first explain that the extraction-accumulation state refers to the process in a thermodynamic system where the internal vapor pressure decreases due to external extraction, causing the vapor to diffuse outward. During this process, the state of matter changes differently under different temperature and pressure conditions, and can be divided into superheated, two-phase (phase transition), and subcooled stages. The superheated stage refers to the portion of a substance's liquid region where the temperature exceeds its normal boiling point. In this superheated state, although the liquid's interior is already high, significant surface evaporation has not yet begun. Further heating may cause the superheated liquid to suddenly boil, resulting in a dramatic release of vapor. The two-phase stage refers to the temperature and pressure region where a substance exists simultaneously in both liquid and vapor phases. Within this region, the substance can coexist as both gas and liquid. The subcooled stage refers to the portion of a substance's liquid region where the temperature is below its normal boiling point. Subcooling typically occurs when a liquid is rapidly cooled to a temperature below its saturated vapor pressure. In this supercooled state, a triggering factor, such as the introduction of a bubble or agitation, can cause the liquid to boil rapidly.

[0056] Based on this, we can understand that the condensate and extraction steam flow in the low-pressure heater in a countercurrent arrangement. During the heat exchange between the hot and cold fluids, the extraction steam on the low-pressure heater side is divided into three segments based on the extraction steam's aggregation state: a superheated segment, a two-phase segment (phase change segment), and a subcooled segment. Based on the results of this segmentation, a segmented lumped parameter model was established for the countercurrent heat exchange process between condensate and extraction steam. The length of each segment is a time-dependent variable. This method of solving partial differential equations in which the boundary moves with time is called the moving boundary method.

[0057] It should also be pointed out that for the segmented lumped parameter models of the superheating section, two-phase section (phase change section), and subcooling section, in the specific modeling process, only the parameter changes of the extraction steam and condensate along the flow direction are considered, and the differences in their distribution parameters on the pipe cross section are ignored. At the same time, it is assumed that the extraction steam and condensate temperatures are the same in the circumferential direction of the pipe. In this way, the energy conservation, mass conservation, and physical property equations of steam heat release in the heat exchange process between the extraction steam superheating section, two-phase section, and subcooling section and the condensate are constructed to obtain the steam heat release model. At the same time, the energy conservation, mass conservation, and physical property equations of condensate heat absorption in the heat exchange process between the extraction steam superheating section, two-phase section, and subcooling section and the condensate are constructed to obtain the condensate heat absorption model.

[0058] In addition, in the process of constructing the equation, the independent variable is time. That is, the functions involved in the steam heat release model and the condensate heat absorption model include: the functions of the average temperature and length of the superheating section over time, the functions of the average temperature and length of the phase change section over time, and the functions of the average temperature and length of the subcooling section over time.

[0059] It should be noted that the method of constructing the steam heat release model and the condensate heat absorption model provided by the embodiment of the present invention is a one-dimensional modeling along the axial main flow direction. Compared with the three-dimensional modeling used in the prior art, the one-dimensional modeling is more suitable for the simulation of the transient part of the power grid. For the simulation of dynamic characteristics, the embodiment of the present invention introduces the moving boundary method into the dynamic heat exchange of the thermal power condensate throttling frequency regulation simulation. The moving boundary method does not consider the difference in the state parameters of each spatial node after discretization in the three sections, but regards each section as a whole. However, the length of each section changes with time. This method actually considers the difference in the heat transfer coefficient of the three sections and the change in the length of each section. The number of unknowns is less than the discrete situation of the entire heat exchange section, and it meets the requirements of simulation accuracy and speed. A fast and accurate simulation method is the prerequisite for realizing the power grid frequency security analysis. By mastering the dynamic process of the power plant load response from the frequency difference exceeding the dead zone to returning to the dead zone, it can provide a basis for the power plant primary frequency regulation control and power grid frequency security analysis.

[0060] Furthermore, in some embodiments, the steam heat release model includes:

[0061] Overheating section:

[0062] Among them, it should be pointed out that the subscript h1s is the average value of the superheat section, 1s is the inlet value of the superheat section, and the subscript c,h1s is the average temperature of the condensate section corresponding to the two-phase extraction steam. is the average density of the superheat section, is the average flow rate in the superheat section, τ For time, x is the distance along the flow direction, is the average enthalpy value of the superheating section, is the average pressure of the superheat section, is the average heat transfer coefficient of the superheating section, is the average temperature of the superheat section, The average temperature of the condensate section corresponding to the two-phase extraction steam, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam, is the inlet density value of the superheating section, is the inlet value of the superheating section flow rate, is the inlet value of superheating section enthalpy, is the inlet pressure value of the superheat section, is the inlet temperature value of the superheat section;

[0063] Two-phase section:

[0064] Among them, it should be pointed out that the subscript h2 represents the average value of the two-phase segment, the subscript sl represents the value of saturated steam, and the subscript sv represents the value of saturated water, and the subscripts c and h2 represent the average temperature of the condensate section corresponding to the superheated section extraction steam. is the average density of the two-phase segment, is the average flow velocity of the two-phase section, τ For time, x is the distance along the flow direction, is the average enthalpy value of the two-phase section, is the average pressure of the two-phase section, is the average heat transfer coefficient of the two-phase section, is the average temperature of the two-phase segment, is the average temperature of the condensate section corresponding to the extraction steam in the superheating section, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam, is the density of saturated steam, λ is the dryness, is the density of saturated water, is the saturated steam enthalpy;

[0065] Subcooling section:

[0066] Among them, it should be pointed out that the subscript h1v represents the average value of the subcooling section, and the subscript c,h1v represents the average temperature of the condensate section corresponding to the steam extraction in the subcooling section. is the average density of the supercooling section, is the average flow velocity in the supercooling section, τ For time, x is the distance along the flow direction, is the average enthalpy value of the supercooling section, is the average pressure of the supercooling section, is the average heat transfer coefficient of the subcooling section, is the average temperature of the supercooling section, is the average temperature of the condensate section corresponding to the extraction steam in the subcooling section, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam.

[0067] Furthermore, in some embodiments, the condensed water heat absorption model includes:

[0068]

[0069] Among them, the subscript c represents the average condensate level corresponding to the subcooling, two-phase and superheating extraction steam. is the average density of condensate corresponding to each extraction section of subcooling, two-phase and superheating. is the average condensate flow rate corresponding to each extraction section of subcooling, two-phase and superheating, τ For time, x is the distance along the flow direction, is the average value of the condensate heat transfer coefficient corresponding to each section of extraction steam: subcooling, two-phase, and superheating. is the average condensate temperature corresponding to each extraction section of subcooling, two-phase and superheating. is the average specific heat capacity of condensate corresponding to each extraction section of subcooling, two-phase and superheating, is the average temperature of the two-phase segment, is the average temperature of the supercooling section, is the average temperature of the superheat section, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam.

[0070] Furthermore, the present invention does not limit the construction method of the flow characteristic equation of the steam extraction pipeline and the turbine flow-power dynamic response equation, and they can be constructed according to actual conditions.

[0071] It should be noted that the steam extraction pipeline referred to in the embodiment of the present invention is a steam extraction pipeline connecting the steam extraction point of the steam turbine and the low-pressure heater.

[0072] In some embodiments, the flow characteristic equation of the extraction steam pipeline includes:

[0073]

[0074] in, is the characteristic coefficient of the extraction steam piping group, is the extraction point pressure on the turbine side, is the extraction steam voltage pressure on the low-pressure heater side; is the extraction steam mass flow rate entering the low-pressure heater for heat exchange, Ais the heat exchange area of ​​condensate and extraction steam, is the average density, is the average flow rate.

[0075] In some embodiments, the turbine flow-power dynamic response equation can directly adopt the IEEE standard model of the turbine during the primary frequency modulation process, which will not be described in detail in the present invention.

[0076] Step 120: In response to the voltage frequency difference exceeding the dead zone, a condensate flow rate step signal is obtained, and the condensate flow rate step signal is input into a pre-built thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment.

[0077] Once the simulation model is complete, a frequency modulation simulation can be performed. During the actual calculation, the steam heat release model and the condensate heat absorption model together form a dynamic heat exchange model between the condensate and extraction steam in the low-pressure heater, based on the moving boundary method. This model primarily calculates the pressure at the extraction steam inlet of the low-pressure heater and the condensate temperature rise process. The functions involved in the calculation include the time-dependent average temperature and length of the superheating section, the time-dependent average temperature and length of the phase change section, and the time-dependent average temperature and length of the subcooling section. The inputs are the dynamic values ​​of the extraction steam flow rate, the dynamic values ​​of the condensate flow rate (condensate flow rate step signal), and the inlet temperatures of both. The output is the extraction steam inlet pressure curve and the condensate outlet temperature.

[0078] On this basis, it should be noted that the dynamic value of the extraction steam flow rate input is determined by the turbine's low-pressure cylinder extraction steam pressure, the low-pressure heater-side extraction steam inlet pressure, and the pipe resistance coefficient. These factors are incorporated into the extraction pipe flow characteristic equation. This means that the steam heat release model and the condensate heat absorption model (a dynamic heat exchange model between the low-pressure heater condensate and extraction steam based on the moving boundary method) must be coupled with the extraction pipe flow characteristic equation.

[0079] In addition, the result of the frequency modulation simulation is the dynamic value of the turbine power increment. In other words, it is necessary to understand how the transient work of the turbine changes with the extraction steam flow rate. In other words, the turbine flow-power dynamic response equation needs to be jointly solved.

[0080] In some embodiments, the step of inputting the condensate flow rate step signal into a pre-built thermal power unit simulation model for simulation calculation to obtain a dynamic value of the steam turbine power increment specifically includes:

[0081] Obtaining initial parameters; wherein the initial parameters include the initial pressure of the extraction point, the initial temperature of the extraction point, the condensate inlet temperature, the condensate inlet pressure and the target load;

[0082] Inputting the initial parameters into the thermal power unit simulation model for solving to obtain steady-state parameters;

[0083] The steady-state parameters and the condensate flow rate step signal are input into the thermal power unit simulation model for iterative solution to obtain a dynamic value of the steam turbine power increment.

[0084] Specifically, during the dynamic frequency regulation simulation, the initial moment is when the grid frequency difference exceeds the dead zone, and the final moment is when the grid frequency difference returns to the dead zone. The overall input of this simulation is the condensate flow rate step signal, and the output is the dynamic value of the turbine power increment. The known quantities include the grid frequency difference curve throughout the frequency regulation process, the initial pressure and temperature at the steam extraction point, and the condensate inlet temperature and pressure.

[0085] During the solution process, the steady-state parameters are first solved. The key is to find the equilibrium point, setting the unsteady-state terms in each equation of the thermal power plant simulation model to zero. In practice, initial parameters, including the target load, are input into the thermal power plant simulation model to determine the steady-state parameters of each equation. It should be noted that the target load can be any load value of the current thermal power plant, and this is not a limitation of the present invention.

[0086] Then the dynamic process is solved, the steady-state parameters and the condensate flow rate step signal are input into the various equations of the thermal power unit simulation model for iterative solution, and finally the dynamic value of the turbine power increment is obtained.

[0087] In some embodiments, inputting the steady-state parameter and the condensate flow rate step signal into the thermal power unit simulation model for iterative solution to obtain a dynamic value of the turbine power increment specifically includes:

[0088] S1: inputting the steady-state parameters and the initial values ​​of the condensate flow rate step signal into the thermal power unit simulation model to obtain the parameter values ​​at the initial moment;

[0089] S2: Inputting the parameter values ​​at the initial moment into the simulation model of the thermal power unit to obtain a target iterative formula; the target iterative formula includes the turbine power iterative equations at the current moment and the previous moment;

[0090] S3: Set the turbine power at the current time step as an assumed value, solve the current equation according to the assumed value, substitute the solution result into the physical property equation of the subcooling section for verification, and if the equation is satisfied, record the assumed value and jump to step S4; if the equation is not satisfied, update the assumed value according to the preset power value iteration rule, and repeat step S3; wherein the current equation includes the steam heat release model and steam heat release model of the superheating section, the steam heat release model and steam heat release model of the two-phase section, and the mass conservation and energy conservation equations of the subcooling section;

[0091] S4: Increment the current time step by one, and repeat steps S3-S4 until the turbine power curve obtained according to the assumed value meets the preset end condition, and obtain the turbine power increment dynamic value according to the turbine power curve.

[0092] Specifically, if Figure 2 As shown, the following steps are included:

[0093] In step S1, the condensate pump frequency change (the initial value of the condensate flow rate step signal) and initial steady-state operating parameter values ​​(steady-state parameters) are first input into the thermal power unit simulation model to determine the initial parameter values, including the condensate temperature and pressure at each node. It should be noted that the condensate pump frequency change input serves as a boundary condition in the calculation.

[0094] In step S2, the temperature and pressure values ​​of each node of the low-pressure heater at the initial moment are input into the thermal power unit simulation model to obtain the target iterative formula of t and (t-1).

[0095] In step S3, the system of equations at time t1 (the current time step) is solved. First, the p-value for this step is assumed to be an assumed value. The current equations are solved sequentially based on the assumed p-value. The current equations include all equations for the superheated region, all equations for the two-phase region, and the mass and energy conservation equations for the subcooling region. The resulting solution includes the average condensate temperature. This average condensate temperature is substituted into the subcooling region heat transfer equation (and the condensate heat transfer equation) to determine if the equation holds. If so, the process proceeds to step (t+1). Otherwise, S3 is repeated according to the power value iteration rule.

[0096] It should be pointed out that the power value iteration rule must determine the direction, and calculate p one step in each direction, whichever is closer to 0. Repeat this 100 times until the heat exchange coefficient is less than 0.001.

[0097] In step S4, the process proceeds to step (t+1), ultimately obtaining the dynamic curves p(i)-i and min(i)-i, and thus obtaining the turbine power curve and the dynamic value of the turbine power increment. Here, i represents the time instant, the p(i)-i curve represents the pressure (p) versus time at each moment, and the min(i)-i curve represents the turbine inlet flow rate (min) versus time at each moment.

[0098] Based on the above embodiments, in some embodiments, the above solution process may be simplified by combining one or more of the following methods:

[0099] 1) Use interpolation instead of refprop to solve the problem mathematically instead of looking up the table;

[0100] 2) Use Mathematica to reduce numerical rounding errors;

[0101] 3) Use an explicit iteration format.

[0102] The present invention provides a method for dynamic simulation of primary frequency regulation based on a thermal power condensate throttling strategy. The method uses a moving boundary method to establish a steam heat release model and a condensate heat absorption model along the flow direction of the hot and cold fluids in the thermal power unit based on the extraction steam aggregation state during the heat exchange process. A thermal power unit simulation model is obtained based on a pre-established flow characteristic equation for the extraction steam pipeline, a pre-established turbine flow-power dynamic response equation, the steam heat release model, and the condensate heat absorption model. In response to a voltage frequency difference exceeding a dead zone, a condensate flow step signal is obtained and input into the pre-established thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment. The present invention utilizes the moving boundary method to model the dynamic heat exchange process of the thermal power unit, and only considers one-dimensional modeling along the axial main flow direction. This method combines the advantages of fast and accurate simulation, achieving high-precision and high-speed frequency regulation dynamic simulation.

[0103] The following describes the primary frequency regulation dynamic simulation device based on the thermal power condensate throttling strategy provided by the present invention. The primary frequency regulation dynamic simulation device based on the thermal power condensate throttling strategy described below and the primary frequency regulation dynamic simulation method based on the thermal power condensate throttling strategy described above can be used for reference. Figure 3 As shown, the device includes:

[0104] The model unit 310 is configured to establish a steam heat release model and a condensate heat absorption model along the flow direction of the cold and hot fluids according to the extraction steam aggregation state during the heat exchange process of the cold and hot fluids of the thermal power unit using a moving boundary method; and obtain a thermal power unit simulation model based on a pre-established flow characteristic equation of the extraction steam pipeline, a pre-established steam turbine flow-power dynamic response equation, the steam heat release model, and the condensate heat absorption model.

[0105] The simulation unit 320 is used to obtain a condensate flow step signal in response to the voltage frequency difference exceeding the dead zone, and input the condensate flow step signal into a pre-built thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment.

[0106] According to the present invention, a primary frequency regulation dynamic simulation device based on a thermal power condensate throttling strategy is provided. According to the extraction steam aggregation state of the cold and hot fluid heat exchange process of the thermal power unit, a steam heat release model and a condensate heat absorption model are established along the flow direction of the cold and hot fluids using the moving boundary method. Specifically, the device includes:

[0107] According to parameter changes of the cold and hot fluids along the flow direction during the heat exchange process, the heat exchange process is divided into a superheating section, a two-phase section, and a subcooling section, and the lengths of the superheating section, the two-phase section, and the subcooling section are set as time-dependent variables;

[0108] The energy conservation, mass conservation and physical property equations of steam heat release in the superheating section, two-phase section and subcooling section are constructed in sequence to obtain a steam heat release model; the energy conservation, mass conservation and physical property equations of condensate heat absorption in the superheating section, two-phase section and subcooling section are constructed in sequence to obtain a condensate heat absorption model.

[0109] According to a primary frequency regulation dynamic simulation device based on a thermal power condensate throttling strategy provided by the present invention, the condensate flow rate step signal is input into a pre-built thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment, specifically including:

[0110] Obtaining initial parameters; wherein the initial parameters include the initial pressure of the extraction point, the initial temperature of the extraction point, the condensate inlet temperature, the condensate inlet pressure and the target load;

[0111] Inputting the initial parameters into the thermal power unit simulation model for solving to obtain steady-state parameters;

[0112] The steady-state parameters and the condensate flow rate step signal are input into the thermal power unit simulation model for iterative solution to obtain a dynamic value of the steam turbine power increment.

[0113] According to a primary frequency regulation dynamic simulation device based on a thermal power condensate throttling strategy provided by the present invention, the steady-state parameters and the condensate flow rate step signal are input into the thermal power unit simulation model for iterative solution to obtain a dynamic value of the turbine power increment, specifically including:

[0114] S1: inputting the steady-state parameters and the initial values ​​of the condensate flow rate step signal into the thermal power unit simulation model to obtain the parameter values ​​at the initial moment;

[0115] S2: Inputting the parameter values ​​at the initial moment into the simulation model of the thermal power unit to obtain a target iterative formula; the target iterative formula includes the turbine power iterative equations at the current moment and the previous moment;

[0116] S3: Set the turbine power at the current time step as an assumed value, solve the current equation according to the assumed value, substitute the solution result into the physical property equation of the subcooling section for verification, and if the equation is satisfied, record the assumed value and jump to step S4; if the equation is not satisfied, update the assumed value according to the preset power value iteration rule, and repeat step S3; wherein the current equation includes the steam heat release model and steam heat release model of the superheating section, the steam heat release model and steam heat release model of the two-phase section, and the mass conservation and energy conservation equations of the subcooling section;

[0117] S4: Increment the current time step by one, and repeat steps S3-S4 until the turbine power curve obtained according to the assumed value meets the preset end condition, and obtain the turbine power increment dynamic value according to the turbine power curve.

[0118] According to a primary frequency regulation dynamic simulation device based on a thermal power condensate throttling strategy provided by the present invention, the steam heat release model includes:

[0119] Overheating section:

[0120] in, is the average density of the superheat section, is the average flow rate in the superheat section, τ For time, x is the distance along the flow direction, is the average enthalpy value of the superheating section, is the average pressure of the superheat section, is the average heat transfer coefficient of the superheating section, is the average temperature of the superheat section, The average temperature of the condensate section corresponding to the two-phase extraction steam, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam, is the inlet density value of the superheating section, is the inlet value of the superheating section flow rate, is the inlet value of superheating section enthalpy, is the inlet pressure value of the superheat section, is the inlet temperature value of the superheat section;

[0121] Two-phase section:

[0122] in, is the average density of the two-phase segment, is the average flow velocity of the two-phase section, τ For time, x is the distance along the flow direction, is the average enthalpy value of the two-phase section, is the average pressure of the two-phase section, is the average heat transfer coefficient of the two-phase section, is the average temperature of the two-phase segment, is the average temperature of the condensate section corresponding to the extraction steam in the superheating section, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam, is the density of saturated steam, λ is the dryness, is the density of saturated water, is the saturated steam enthalpy;

[0123] Subcooling section:

[0124] in, is the average density of the supercooling section, is the average flow velocity in the supercooling section, τ For time, x is the distance along the flow direction, is the average enthalpy value of the supercooling section, is the average pressure of the supercooling section, is the average heat transfer coefficient of the subcooling section, is the average temperature of the supercooling section, is the average temperature of the condensate section corresponding to the extraction steam in the subcooling section, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam.

[0125] According to a primary frequency regulation dynamic simulation device based on a thermal power condensate throttling strategy provided by the present invention, the condensate heat absorption model includes:

[0126]

[0127] in, is the average density of condensate corresponding to each extraction section of subcooling, two-phase and superheating. is the average condensate flow rate corresponding to each extraction section of subcooling, two-phase and superheating, τ For time, x is the distance along the flow direction, is the average value of the condensate heat transfer coefficient corresponding to each section of extraction steam: subcooling, two-phase, and superheating. is the average condensate temperature corresponding to each extraction section of subcooling, two-phase and superheating. is the average specific heat capacity of condensate corresponding to each extraction section of subcooling, two-phase and superheating, is the average temperature of the two-phase segment, is the average temperature of the supercooling section, is the average temperature of the superheat section, D is the pipe diameter, A is the heat exchange area of ​​condensate and extraction steam.

[0128] The present invention provides a primary frequency regulation dynamic simulation device based on a thermal power condensate throttling strategy. The device utilizes a moving boundary method to establish a steam heat release model and a condensate heat absorption model along the flow direction of the hot and cold fluids in the thermal power unit based on the extraction steam aggregation state during the heat exchange process. A thermal power unit simulation model is obtained based on a pre-established flow characteristic equation for the extraction steam pipeline, a pre-established turbine flow-power dynamic response equation, the steam heat release model, and the condensate heat absorption model. In response to a voltage-frequency difference exceeding a dead zone, a condensate flow step signal is obtained, which is input into the pre-established thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment. The present invention utilizes the moving boundary method to model the dynamic heat exchange process of the thermal power unit, and only considers one-dimensional modeling along the axial main flow direction. This method combines the advantages of fast and accurate simulation, achieving high-precision and high-speed frequency regulation dynamic simulation.

[0129] Figure 4 An example of a physical structure diagram of an electronic device is shown below. Figure 4 As shown, the electronic device may include: a processor (processor) 410, a communication interface (Communications Interface) 420, a memory (memory) 430 and a communication bus 440, wherein the processor 410, the communication interface 420, and the memory 430 communicate with each other through the communication bus 440. The processor 410 can call the logic instructions in the memory 430 to execute a primary frequency regulation dynamic simulation method based on the thermal power condensate throttling strategy, the method including: according to the extraction steam aggregation state of the cold and hot fluid heat exchange process of the thermal power unit, using the moving boundary method to establish a steam heat release model and a condensate heat absorption model along the flow direction of the cold and hot fluids; according to the pre-constructed flow characteristic equation of the extraction steam pipeline, the pre-constructed turbine flow-power dynamic response equation, the steam heat release model and the condensate heat absorption model, a thermal power unit simulation model is obtained; in response to the voltage frequency difference exceeding the dead zone, a condensate flow step signal is obtained, and the condensate flow step signal is input into the pre-constructed thermal power unit simulation model for simulation calculation to obtain the dynamic value of the turbine power increment.

[0130] Furthermore, the logic instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0131] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the primary frequency regulation dynamic simulation method based on the thermal power condensate throttling strategy provided by the above methods, the method including: according to the extraction steam aggregation state of the cold and hot fluid heat exchange process of the thermal power unit, using the moving boundary method to establish a steam heat release model and a condensate heat absorption model along the flow direction of the cold and hot fluids; according to the pre-constructed flow characteristic equation of the extraction steam pipeline, the pre-constructed turbine flow-power dynamic response equation, the steam heat release model and the condensate heat absorption model, a thermal power unit simulation model is obtained; in response to the voltage frequency difference exceeding the dead zone, a condensate flow step signal is obtained, and the condensate flow step signal is input into the pre-constructed thermal power unit simulation model for simulation calculation to obtain the dynamic value of the turbine power increment.

[0132] On the other hand, the present invention also provides a non-transient computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a primary frequency regulation dynamic simulation method based on the thermal power condensate throttling strategy provided by the above-mentioned methods, the method comprising: according to the extraction steam aggregation state of the cold and hot fluid heat exchange process of the thermal power unit, using the moving boundary method to establish a steam heat release model and a condensate heat absorption model along the flow direction of the cold and hot fluids; according to the pre-constructed flow characteristic equation of the extraction steam pipeline, the pre-constructed turbine flow-power dynamic response equation, the steam heat release model and the condensate heat absorption model, a thermal power unit simulation model is obtained; in response to the voltage frequency difference exceeding the dead zone, a condensate flow step signal is obtained, and the condensate flow step signal is input into the pre-constructed thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment.

[0133] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0134] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A dynamic simulation method for primary frequency regulation based on thermal power condensate throttling strategy, applied to thermal power units, characterized in that: include: According to the extraction steam aggregation state of the hot and cold fluid heat exchange process of the thermal power unit, a steam heat release model and a condensate heat absorption model are established along the flow direction of the hot and cold fluids using the moving boundary method; a thermal power unit simulation model is obtained based on a pre-constructed flow characteristic equation of the extraction steam pipeline, a pre-constructed turbine flow-power dynamic response equation, the steam heat release model, and the condensate heat absorption model; In response to the voltage frequency difference exceeding the dead zone, a condensate flow rate step signal is obtained, and the condensate flow rate step signal is input into a pre-built thermal power unit simulation model for simulation calculation to obtain a dynamic value of the turbine power increment.

2. The method for dynamic simulation of primary frequency regulation based on thermal power condensate throttling strategy according to claim 1 is characterized in that: According to the extraction steam aggregation state of the hot and cold fluids in the thermal power unit heat exchange process, a steam heat release model and a condensed water heat absorption model are established along the flow direction of the hot and cold fluids using the moving boundary method, specifically including: According to parameter changes of the cold and hot fluids along the flow direction during the heat exchange process, the heat exchange process is divided into a superheating section, a two-phase section, and a subcooling section, and the lengths of the superheating section, the two-phase section, and the subcooling section are set as time-dependent variables; The energy conservation, mass conservation and physical property equations of steam heat release in the superheating section, two-phase section and subcooling section are constructed in sequence to obtain a steam heat release model; the energy conservation, mass conservation and physical property equations of condensate heat absorption in the superheating section, two-phase section and subcooling section are constructed in sequence to obtain a condensate heat absorption model.

3. The method for dynamic simulation of primary frequency regulation based on thermal power condensate throttling strategy according to claim 2 is characterized in that: The step of inputting the condensate flow rate step signal into a pre-built thermal power unit simulation model for simulation calculation to obtain a dynamic value of the steam turbine power increment specifically includes: Obtaining initial parameters; wherein the initial parameters include the initial pressure of the extraction point, the initial temperature of the extraction point, the condensate inlet temperature, the condensate inlet pressure and the target load; Inputting the initial parameters into the thermal power unit simulation model for solving to obtain steady-state parameters; The steady-state parameters and the condensate flow rate step signal are input into the thermal power unit simulation model for iterative solution to obtain a dynamic value of the turbine power increment.

4. The method for dynamic simulation of primary frequency regulation based on thermal power condensate throttling strategy according to claim 3 is characterized in that: The step of inputting the steady-state parameter and the condensate flow rate step signal into the thermal power unit simulation model for iterative solution to obtain the dynamic value of the steam turbine power increment specifically includes: S1: inputting the steady-state parameters and the initial values ​​of the condensate flow rate step signal into the thermal power unit simulation model to obtain the parameter values ​​at the initial moment; S2: Inputting the parameter values ​​at the initial moment into the simulation model of the thermal power unit to obtain a target iterative formula; the target iterative formula includes the turbine power iterative equations at the current moment and the previous moment; S3: Set the turbine power at the current time step as an assumed value, solve the current equation according to the assumed value, substitute the solution result into the physical property equation of the subcooling section for verification, and if the equation is satisfied, record the assumed value and jump to step S4; if the equation is not satisfied, update the assumed value according to the preset power value iteration rule, and repeat step S3; wherein the current equation includes the steam heat release model and steam heat release model of the superheating section, the steam heat release model and steam heat release model of the two-phase section, and the mass conservation and energy conservation equations of the subcooling section; S4: Increment the current time step by one, and repeat steps S3-S4 until the turbine power curve obtained according to the assumed value meets the preset end condition, and obtain the turbine power increment dynamic value according to the turbine power curve.

5. The method for dynamic simulation of primary frequency regulation based on thermal power condensate throttling strategy according to claim 1 or 2, characterized in that: The steam heat release model includes: Overheating section: Among them, ρ h1s is the average density of the superheating section, u h1s is the average flow velocity in the superheating section, τ is time, x is the distance along the flow direction, h h1s is the average enthalpy value of the superheating section, P h1s is the average pressure of the superheat section, k h1s is the average heat transfer coefficient of the superheating section, T h1s is the average temperature of the superheat section, T c,h1s The average temperature of the condensate section corresponding to the two-phase extraction steam section, D is the pipe diameter, A is the heat exchange area between the condensate and the extraction steam, ρ 1s is the inlet density value of the superheating section, u 1s is the inlet flow rate value of the superheating section, h 1s is the inlet value of superheating section enthalpy, P 1s is the inlet pressure value of the superheating section, T 1s is the inlet temperature value of the superheat section; Two-phase section: Among them, ρ h2 is the average density of the two-phase segment, u h2 is the average velocity of the two-phase section, τ is time, x is the distance along the flow direction, h h2 is the average enthalpy value of the two-phase section, P h2 is the average pressure of the two-phase section, k h2 is the average heat transfer coefficient of the two-phase section, T h2 is the average temperature of the two-phase segment, T c,h2 is the average temperature of the condensate section corresponding to the extraction steam in the superheating section, D is the pipe diameter, A is the heat exchange area between the condensate and the extraction steam, ρ sl is the density of saturated steam, λ is the dryness, ρ sv is the density of saturated water, h sl is the saturated steam enthalpy, h sv is the saturated water enthalpy; Subcooling section: Among them, ρ h1v is the average density of the supercooling section, u h1v is the average velocity of the supercooling section, τ is the time, x is the distance along the flow direction, h h1v is the average enthalpy value of the supercooling section, P h1v is the average pressure of the supercooling section, k h1v is the average heat transfer coefficient of the subcooling section, T h1v is the average temperature of the supercooling section, T c,h1v is the average temperature of the condensate section corresponding to the extraction steam in the subcooling section, D is the pipe diameter, and A is the heat exchange area between the condensate and the extraction steam.

6. The method for dynamic simulation of primary frequency regulation based on thermal power condensate throttling strategy according to claim 1 or 2, characterized in that: The condensed water heat absorption model includes: Among them, ρ c is the average density of condensate corresponding to each extraction section of subcooling, two-phase and superheating, u c is the average condensate flow rate corresponding to each section of subcooling, two-phase, and superheating extraction, τ is time, x is the distance along the flow direction, k c is the average value of the condensate heat transfer coefficient corresponding to each extraction section of subcooling, two-phase and superheating, T c is the average condensate temperature corresponding to each extraction section of subcooling, two-phase and superheating, c p T is the average specific heat capacity of condensate corresponding to each extraction section of subcooling, two-phase and superheating. h2 is the average temperature of the two-phase segment, T h1v is the average temperature of the supercooling section, T h1s is the average temperature of the superheat section, D is the pipe diameter, and A is the heat exchange area of ​​condensate and extraction steam.

7. A dynamic simulation device for primary frequency regulation based on thermal power condensate throttling strategy, applied to thermal power units, characterized in that: include: A model unit is configured to establish a steam heat release model and a condensate heat absorption model along the flow direction of the cold and hot fluids according to the extraction steam aggregation state in the heat exchange process of the cold and hot fluids of the thermal power unit using a moving boundary method; and obtain a thermal power unit simulation model according to a pre-established flow characteristic equation of the extraction steam pipeline, a pre-established steam turbine flow-power dynamic response equation, the steam heat release model, and the condensate heat absorption model; The simulation unit is used to obtain a condensate flow step signal in response to the voltage frequency difference exceeding the dead zone, input the condensate flow step signal into a pre-built thermal power unit simulation model for simulation calculation, and obtain a dynamic value of the turbine power increment.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the primary frequency regulation dynamic simulation method based on the thermal power condensate throttling strategy as described in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for dynamic simulation of primary frequency regulation based on the thermal power condensate throttling strategy as claimed in any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method for dynamic simulation of primary frequency regulation based on the thermal power condensate throttling strategy as claimed in any one of claims 1 to 6 is implemented.

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