Method and device for analyzing throttling process of condensed water of coal-fired unit and electronic equipment

Abstract

The invention provides a condensation water throttling process analysis method and device of a coal-fired unit and electronic equipment, and belongs to the technical field of coal-fired units. The method comprises the following steps: constructing a dynamic model of a coal-fired unit based on a Modelica language; obtaining the condensed water throttling amount and the adjusting time under different operation conditions; respectively inputting the condensed water throttling amount and the adjusting time under different operation conditions into the dynamic model to obtain the output power of the dynamic model under all operation conditions; a fitting function is constructed based on the condensation water throttling amount and the adjustment time under different operation conditions and the output power under all the operation conditions; and carrying out dynamic characteristic analysis on the output power of the dynamic model in the condensation water throttling process based on the fitting function. The method is used for solving the problem that the effects of power grid frequency modulation and power plant regulation and control are poor due to the lack of a technical scheme for accurately and objectively analyzing the dynamic characteristics of the output power of the coal-fired unit in the condensed water throttling regulation process under different working conditions in the existing scheme.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-fired units, and in particular to a condensate throttling process analysis method for a coal-fired unit, a condensate throttling process analysis device for a coal-fired unit, an electronic device, a machine-readable storage medium and a computer program product. Background Art

[0002] As the installed capacity of new energy power systems continues to expand, their intermittent and highly random nature poses a huge crisis to the power grid. As the "ballast stone" for stable and safe power supply, coal-fired units need to continuously enhance their flexibility to absorb more new energy power systems.

[0003] Condensate throttling regulation is widely used in primary frequency regulation schemes because it can quickly call upon the energy storage of the steam turbine system and realize rapid power regulation of coal-fired units. However, the existing schemes lack technical solutions that can accurately and objectively analyze the dynamic characteristics of the output power of coal-fired units under different working conditions when using condensate throttling regulation for different types of coal-fired units, resulting in poor results in grid frequency regulation and power plant regulation. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a condensate throttling process analysis method for a coal-fired unit, a condensate throttling process analysis device for a coal-fired unit, an electronic device, a machine-readable storage medium and a computer program product, so as to solve the defect that the existing solutions lack a technical solution for accurately and objectively analyzing the dynamic characteristics of the output power of the coal-fired unit in the process of condensate throttling regulation under different operating conditions based on the actual system and equipment of the power plant, resulting in poor effects of power grid frequency regulation and power plant regulation.

[0005] In order to achieve the above object, an embodiment of the present invention provides a method for analyzing a condensate throttling process of a coal-fired unit, comprising: Construct the dynamic model of coal-fired units based on Modelica language; Obtain condensate water saving volume and adjustment time under different operating conditions; Inputting the condensate water saving amount and the adjustment time under the different operating conditions into the dynamic model respectively, and obtaining the output power of the dynamic model under all operating conditions; A fitting function is constructed based on the condensate water saving amount and the adjustment time under the different operating conditions, and the output power under all operating conditions; the fitting function represents the functional relationship between the condensate water saving amount and the output power increment of the dynamic model; The dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process is performed based on the fitting function.

[0006] Optionally, constructing a fitting function based on the condensate water saving amount and adjustment time under the different operating conditions and the output power under the different operating conditions includes: Determine the output power increment corresponding to the condensate water saving amount under different operating conditions based on the difference between the output power of the dynamic model at the end of the adjustment time and the output power of the dynamic model at the beginning of the adjustment time; An exponential function is fitted based on the condensate saving flow under different operating conditions and the output power increment corresponding to the condensate saving flow under the different operating conditions, and the exponential function is used as the fitting function.

[0007] Optionally, the exponential function is expressed by the following formula: ; in, A 1. t 1. y 0 represents the preset coefficient respectively; x represents the condensate throttling amount of the dynamic model in the condensate throttling state; y represents the output power increment of the dynamic model.

[0008] Optionally, the performing the dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function includes: Inputting the condensate saving amount under the different operating conditions into the fitting function to obtain the output power increment range of the dynamic model under all operating conditions; The output power increment corresponding to the condensate water saving flow under the target operating condition is obtained based on the fitting function, and the power regulation rate under the target operating condition is determined based on the output power increment under the target operating condition and the regulation time corresponding to the condensate water saving flow under the target operating condition; wherein the target operating condition is any one of the different operating conditions.

[0009] Optionally, the method further includes: The dynamic exergy of each component is calculated based on the enthalpy value, entropy value and temperature value of each component in the dynamic model, and the exergy loss of each component is calculated based on the input exergy and output exergy of each component.

[0010] On the other hand, an embodiment of the present invention further provides a condensate throttling process analysis device for a coal-fired unit, comprising: Building module for building dynamic models of coal-fired units based on Modelica language; An acquisition module is used to obtain the condensate water saving amount and adjustment time under different operating conditions; A calculation module, used for inputting the condensate water saving amount and the adjustment time under the different operating conditions into the dynamic model respectively, and obtaining the output power of the dynamic model under all operating conditions; A fitting module, used to construct a fitting function based on the condensate water saving flow and adjustment time under the different operating conditions, and the output power under all operating conditions; the fitting function represents the functional relationship between the condensate water saving flow and the output power increment of the dynamic model; The first analysis module is used to perform a dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function.

[0011] Optionally, constructing a fitting function based on the condensate water saving amount and adjustment time under the different operating conditions and the output power under the different operating conditions includes: Determine the output power increment corresponding to the condensate water saving amount under different operating conditions based on the difference between the output power of the dynamic model at the end of the adjustment time and the output power of the dynamic model at the beginning of the adjustment time; An exponential function is fitted based on the condensate saving flow under different operating conditions and the output power increment corresponding to the condensate saving flow under the different operating conditions, and the exponential function is used as the fitting function.

[0012] Optionally, the exponential function is expressed by the following formula: ; in, A 1. t 1. y 0 represents the preset coefficient respectively; x represents the condensate throttling amount of the dynamic model in the condensate throttling state; y represents the output power increment of the dynamic model.

[0013] Optionally, the performing the dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function includes: Inputting the condensate saving amount under the different operating conditions into the fitting function to obtain the output power increment range of the dynamic model under all operating conditions; The output power increment corresponding to the condensate water saving flow under the target operating condition is obtained based on the fitting function, and the power regulation rate under the target operating condition is determined based on the output power increment under the target operating condition and the regulation time corresponding to the condensate water saving flow under the target operating condition; wherein the target operating condition is any one of the different operating conditions.

[0014] Optionally, the device further comprises: The second analysis module is used to calculate the dynamic exergy of each component based on the enthalpy value, entropy value and temperature value of each component in the dynamic model, and calculate the exergy loss of each component based on the input exergy flow and output exergy flow of each component.

[0015] On the other hand, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the condensate throttling process analysis method of the above-mentioned coal-fired unit when executing the program.

[0016] On the other hand, the present invention further provides a machine-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned method for analyzing the condensate throttling process of the coal-fired unit.

[0017] On the other hand, the present invention also provides a computer program product, including a computer program, which, when executed by a processor, implements the above-mentioned condensate throttling process analysis method of the coal-fired unit.

[0018] Through the above technical solution, the dynamic model of the coal-fired unit constructed based on the Modelica language in the embodiment of the present invention is applicable to multiple types of steam turbine systems, and has high applicability and reusability. In addition, the fitting function of the embodiment of the present invention characterizes the functional relationship between the condensate throttling amount and the output power increment of the dynamic model under different operating conditions, and realizes the dynamic characteristic analysis of the output power in the process of condensate throttling regulation under all conditions, thereby improving the effect of power grid frequency regulation and power plant regulation.

[0019] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings: Figure 1 It is a schematic flow chart of the condensate throttling process analysis method provided by the present invention; Figure 2 It is a schematic diagram of the system structure of the supercritical pure condensing steam turbine provided by the present invention; Figure 3 It is a schematic diagram of the dynamic change of output power of the coal-fired unit provided by the present invention when condensate throttling regulation is adopted; Figure 4 It is a schematic diagram of the dynamic change process of the water level inside the deaerator during the condensate throttling process provided by the present invention; Figure 5It is a schematic diagram of condensate throttling regulation of a coal-fired unit under different working conditions provided by the present invention; Figure 6 It is a schematic diagram of the dynamic response process of the input exergy flow and the output exergy flow of the 1# low-pressure heater provided by the present invention; Figure 7 It is a schematic diagram of the dynamic response process of the input exergy flow and the output exergy flow of the 2# low-pressure heater provided by the present invention; Figure 8 It is a schematic diagram of the dynamic response process of the input exergy flow and the output exergy flow of the 3# low-pressure heater provided by the present invention; Fig. 9 It is a schematic diagram of the dynamic response process of the input exergy flow and the output exergy flow of the 4# low-pressure heater provided by the present invention; Fig.10 It is a schematic diagram of the dynamic response process of each level of low exergy loss provided by the present invention; Fig.11 It is a structural schematic diagram of the condensate throttling process analysis device provided by the present invention; Fig.12 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0021] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0022] Method Embodiment Please refer to Figure 1 The embodiment of the present invention provides a method for analyzing the condensate throttling process of a coal-fired unit, comprising: Step 100: construct a dynamic model of the coal-fired unit based on the Modelica language.

[0023] The electronic device constructs a dynamic model of a coal-fired unit based on the Modelica language. The dynamic model of a coal-fired unit constructed based on the Modelica language in the embodiment of the present invention is applicable to multiple types of steam turbine systems, for example, it may include supercritical pure condensing steam turbines, subcritical pure condensing steam turbines, supercritical extraction condensing steam turbines, and subcritical extraction condensing steam turbine models. The dynamic model of a coal-fired unit constructed based on the Modelica language in the embodiment of the present invention has high applicability and reusability.

[0024] The dynamic model of the coal-fired unit in the embodiment of the present invention is explained by taking the system structure of a supercritical pure condensing steam turbine as an example. The supercritical pure condensing steam turbine has 8 levels of non-adjustable heat recovery extraction, and the heat recovery subsystem adopts the form of three highs, four lows and one deoxidation. The dynamic model of the supercritical pure condensing steam turbine includes the dynamic model of the turbine body, high (low) pressure heat recovery heater, deaerator, condenser, condensate pump and feed water pump. Please refer to Figure 2 In the embodiment of the present invention, the dynamic models of high, medium and low pressure cylinders, high (low) pressure regenerative heaters, deaerators, condensers, feed water pumps and condensate pumps are established according to the structural parameters and rated operating conditions of the system thermal equipment. The main design parameters of the supercritical pure condensing steam turbine are shown in Table 1.

[0025] Table 1

[0026] The turbine body model is divided into different stage groups according to the steam extraction section, and the relationship between the flow rate and pressure of each stage group is calculated by the following formula: ; In the above formula: W Indicates the working flow rate under stage group variable working conditions, kg / s; W TRL Indicates the design flow rate under rated conditions of the stage group, kg / s; P 1 represents the inlet working pressure of the stage group under variable working conditions, MPa; P TRL1 Indicates the inlet working pressure of the stage group at rated working conditions, MPa; P 2 represents the outlet working pressure of the stage group under variable working conditions, MPa; P TRL2 Indicates the outlet working pressure of the stage group under rated working conditions, MPa; T Indicates the working temperature before the stage group when the stage group changes working conditions, K; T TRL Indicates the operating temperature before the stage group at the rated operating condition of the stage group, K.

[0027] The steam flow relationship between each stage group is: ; In the above formula: W g,i Indicates the steam intake of this stage group, kg / s; W g,i+1 Indicates the exhaust volume of the previous group, kg / s; W ch,i Indicates the steam extraction volume of this section, kg / s.

[0028] Entropy of the entry level group S g，in , ideal adiabatic enthalpy at outleth g，out * and outlet temperature t g,out Both can be obtained from the thermodynamic property functions of water and water vapor: ; ; ; In the above formula: p g,in Indicates the steam pressure at the stage inlet, MPa; h g,in Indicates the steam enthalpy at the stage group inlet, kJ / kg; p g,out Indicates the steam pressure at the stage outlet, MPa; h g,out Indicates the steam enthalpy at the stage group outlet, kJ / kg.

[0029] The actual outlet enthalpy of the stage group can be calculated by the following formula: ; In the above formula: η eat,i represents the isentropic efficiency of stage group i.

[0030] For the last stage of the low-pressure cylinder, the steam working capacity decreases and enters the two-phase region, and the isentropic efficiency of the stage group also decreases. This part can be calculated by the Bauman formula:

[0031] In the above formula: η eta，i+1 represents the isentropic efficiency of the next level group; η eta，i It represents the isentropic efficiency of this level group; α B represents the isentropic efficiency reduction coefficient.

[0032] The overall mechanical power of the steam turbine is the sum of the power of each cylinder group. The mechanical power of each group can be calculated by the following formula: ; In the above formula: P m,i represents the internal power of stage group i, kW; η m,i Represents the mechanical efficiency of stage group i.

[0033] The deaerator model mainly describes the internal gas-liquid mass conservation and energy conservation as well as the heat exchange between the gas-liquid two phases and the metal wall.

[0034] Conservation of mass inside the deaerator: ; In the above formula: M dea Indicates the total mass inside the deaerator, kg; W ch4 Indicates the four-extraction steam entering the deaerator, kg / s; W bh Indicates the 3# high pressure heater drain flow entering the deaerator, kg / s; W fl Indicates the 1# low feed water flow rate entering the deaerator, kg / s; W cp Indicates the flow rate from the deaerator to the boiler feed water pipeline, kg / s.

[0035] Energy conservation inside the deaerator: ; In the above formula: E dea It represents the total internal energy of vapor and liquid in the deaerator, kJ; h ch4 It represents the specific enthalpy of the steam from the fourth extraction, kJ / kg; h bh It indicates the specific enthalpy of 3# high pressure heater hydrophobicity, kJ / kg; h fl Indicates the specific enthalpy of 1# low-pressure feed water, kJ / kg; h cp It indicates the specific enthalpy of feed water discharged from the deaerator to the boiler feed water pipeline, kJ / kg.

[0036] Energy conservation of metal wall: ; In the above formula: M zs Indicates the mass of the deaerator metal, kg; C zs represents the specific heat capacity of the deaerator metal, kJ / (kg·K); T zs Indicates the metal wall temperature of the deaerator, K; Q int Indicates the heat exchange flow rate received by the deaerator, kW; Q ext Indicates the heat exchange flow rate between the deaerator and the external environment, kW.

[0037] The heat exchange flow inside the deaerator receiver mainly consists of two parts, one is the heat exchange of the vapor phase, and the other is the heat exchange of the liquid phase, which can be calculated by the following formula: ; In the above formula:K g , K l Indicates the heat transfer coefficient between the gas and liquid phases in the deaerator and the metal wall, kW / (m 2 k); A g , A l Represents the contact area between the gas and liquid phases in the deaerator and the metal wall, m 2 ; T g , T l Indicates the temperature of the vapor and liquid phases in the deaerator, K.

[0038] The relationship between the water level in the deaerator and the volume on the water side is shown in the following formula: ; ; In the above formula: V l Indicates the volume of the water side of the deaerator, m 3 ; X Indicates the mass fraction of steam in the deaerator; ρ l Indicates the density of the water side of the deaerator, kg / m 3 ; L Indicates the total length of the deaerator's water storage tank, m; r int Indicates the inner radius of the deaerator's water storage tank, m; y Indicates the water level of the deaerator's storage tank, m.

[0039] The deaerator in the embodiment of the present invention has an inner diameter of 3.864 m and a total length of 20.5 m.

[0040] The dynamic model of the high (low) pressure heater takes the extraction steam inlet of this section as node 1 and the drain outlet as node 6, and divides the heater evenly into 6 nodes. The following is an explanation based on one node.

[0041] Tube side energy balance: ; In the above formula: m g Indicates the water storage capacity of the heater tube, kg; C p It represents the specific heat capacity of water in the tube at constant pressure, kJ / (kg·K); t g1 ,t g2 represents the water temperature in the pipe, K; Qgd Indicates the convective heat transfer in the tube, kW; D g Indicates water flow rate, kg / s.

[0042] The convective heat transfer is calculated by the following formula: ; In the above formula: K gd represents the coefficient; t gz Represents the metal wall temperature, ℃.

[0043] Energy balance of the metal wall: ; In the above formula: C gz Indicates the specific heat capacity of the metal wall involved in heat exchange, kJ / (kg·K); M gz Indicates the mass of the metal wall involved in heat exchange, kg; Q gn Indicates the heat released by steam condensation, kW.

[0044] The heat released by steam condensation can be calculated by the following formula: ; In the above formula: S g Indicates the heat transfer area of ​​the condensation zone tube, m 2 ; α g It represents the condensation heat release coefficient; t bh Indicates saturated steam temperature, ℃.

[0045] The condenser works under a relatively high vacuum condition. The heat is transferred to the outer wall of the metal tube through the condensation of steam, then transferred to the inner wall of the tube, and finally transferred to the cooling water through convection heat transfer.

[0046] The heat released by the condensation of steam onto the outer wall of the metal pipe can be calculated by the following formula: ; In the above formula: Q s Indicates the heat released by steam condensation, kJ / s; α n Indicates the condensation heat transfer coefficient, kW / (m 2 K); S 1 represents the surface area of ​​the outer wall of the metal pipe, m 2 ; T srepresents the saturation temperature of steam, K; T cm1 Represents the outer wall temperature of the metal pipe, K.

[0047] Heat release coefficient of steam condensation α n It can be calculated by the following formula: ; In the above formula: ζ k It represents the local influence coefficient of the air content in the condenser; K kg represents the coefficient; D 2 represents the outer wall of the metal pipe, m; M is with t s , T cm1 The temperature coefficient of interest.

[0048] The mass conservation on the steam side is: ; In the above formula: V Indicates the total volume outside the condenser tube, m 3 ; ρ 1 represents the density of saturated steam, kg / m 3 ; D ck Indicates the steam inlet rate of the condenser, kg / s; D Indicates the condensation amount of the condenser, kg / s.

[0049] The heat transfer from the outer wall of the metal tube to the inner wall can be calculated by the following formula: ; In the above formula: Q w Indicates the heat conduction of the metal pipe wall, kW; α c Indicates the thermal conductivity of the metal pipe wall, kW / (m 2 K); S Represents the average surface area of ​​the metal pipe wall, m 2 ; T cm0 Indicates the inner wall temperature of the metal pipe, K.

[0050] Thermal conductivity of metal pipe wall α c It can be calculated by the following formula: ; In the above formula: d 1 represents the inner diameter of the metal pipe, m; λ1 represents the thermal conductivity of the metal pipe wall kW / (m·K); λ 2 represents the thermal conductivity of the dirt kW / (m·K).

[0051] The convection heat transfer between the inner wall of the metal pipe and water can be calculated by the following formula: ; In the above formula: Q f Represents the convective heat transfer on the inner wall of the metal tube, kW; α c Indicates the convection heat transfer coefficient, kW / (m 2 K); S 0 represents the inner surface of the metal tube, m 2 ; T 1, T 2 represents the inlet and outlet water temperature of the pipe, K.

[0052] The convective heat transfer coefficient between cooling water and the inner wall of the metal tube can be calculated by the following formula: ; In the above formula: K d represents the coefficient; W Indicates the actual flow rate of cooling water in the pipe, kg / s; W 0 represents the flow rate of cooling water in the tube under rated conditions, kg / s.

[0053] The energy conservation on the water side is: ; In the above formula: m 1 represents the amount of water stored in the metal pipe, kg; C p It represents the constant pressure specific heat capacity of cooling water, kJ / (kg·K).

[0054] The energy conservation of the metal tube wall is: ; In the above formula: m gb Indicates the equivalent mass of metal pipe wall and dirt, kg; C gb Indicates the equivalent specific heat capacity of the metal pipe wall and dirt, kJ / (kg·K); Condensate pump and feed water pump, the actual head of both ΔH It can be calculated by the following formula: ; In the above formula: k 1. k 2. k3 represents the coefficient, which is related to the rated working condition of the pump; n Indicates the speed of the water pump, r / m; Q 1 represents the volume flow of the pump, m 3 / s.

[0055] The power consumption of the auxiliary pump is: ; In the above formula: A e represents the coefficient; ρ sh Indicates the density of the transported liquid, kg / m 3 .

[0056] Step 200: Obtain the condensate saving amount and adjustment time under different operating conditions.

[0057] The electronic equipment obtains the parameters of main steam, reheat steam, cooling water, condensate and boiler feed water according to the different operating conditions of the dynamic model of the coal-fired unit. At the same time, the safe operating range of the deaerator and condensate pump is obtained to determine the operability range of the condensate throttling amount and adjustment time. For example, taking the 100%THA (turbine heat acceptance) operating condition of the dynamic model of the coal-fired unit as an example, during normal operation, the condensate flow rate is 1279.23 t / h, and affected by the safe operating range of the condensate pump, the minimum allowable value of the condensate flow rate is 255.8 t / h. The normal water level of the deaerator is maintained at 2.9 m, and the safe operating water level range is [1.5 m, 3.2 m].

[0058] Based on the safe working range of the condensate pump, the embodiment of the present invention can pre-set several groups of simulation schemes. For example, based on the 100% THA working condition, the condensate throttling amount and throttling time are controlled respectively as shown in Table 2: Table 2

[0059] From Table 2, it can be seen that the electronic device of the embodiment of the present invention can obtain solution 1: the condensate saving flow is 1023.43 t·h -1 , the adjustment time is 530s; or obtain solution 2: the condensate saving volume is 768.03t·h -1 , the adjustment time is 710s; or obtain solution 3: the condensate saving volume is 512.43t·h -1 , the adjustment time is 1060s; or obtain scheme 4: the condensate saving volume is 256.83t·h -1, the adjustment time is 2110s. Similarly, the embodiment of the present invention can also obtain the condensate throttling amount and adjustment time of 75%THA and 50%THA working conditions, which is convenient for analyzing the power growth characteristics of the dynamic model in the condensate throttling process and the dynamic laws of the internal parameters under different simulation schemes.

[0060] Step 300: input the condensate saving amount and adjustment time under the different operating conditions into the dynamic model respectively to obtain the output power of the dynamic model under all operating conditions.

[0061] The electronic device inputs the set condensate water saving amount and adjustment time obtained in step 200 into the dynamic model to calculate the incremental characteristics of the power of the coal-fired unit under different operating conditions.

[0062] Take the condensate throttling control scheme as an example. When the turbine system is operating normally, ensure that the internal water level of the deaerator and condenser is within the safe range. PID control is used to control the flow rate by adjusting the speed of the water pump to maintain a stable water level. Among them, the water pump can be a condensate pump or a feed water pump, and the corresponding water level is the condenser water level and the deaerator water level. When the condensate throttling operation is performed, the PID control will no longer maintain the water level near the target value, but the condensate pump will control the condensate flow rate to reach the set condensate throttling amount and adjustment time under different operating conditions, and the feed water pump will keep the boiler feed water constant.

[0063] Please refer to Figure 3 , Figure 3 It shows the trend of the output power of the dynamic model changing with time under several condensate water saving conditions under 100% THA conditions. Figure 4 , Figure 4 It shows the trend of the water level inside the deaerator of the dynamic model with several condensate water saving flows under 100% THA conditions. Similarly, the trend of the output power of the dynamic model with several condensate water saving flows under 75% THA and 50% THA conditions can also be obtained; as well as the trend of the water level inside the deaerator of the dynamic model with condensate water saving flows.

[0064] Step 400: construct a fitting function based on the condensate saving amount and adjustment time under the different operating conditions, and the output power under all operating conditions.

[0065] The electronic device can calculate the output power increment corresponding to the condensate throttling flow under different operating conditions through the output power change before and after the condensate throttling adjustment, and then construct a fitting function based on the condensate throttling flow and the output power increment corresponding to the condensate throttling flow; the fitting function represents the functional relationship between the condensate throttling flow and the output power increment of the dynamic model. For example, the electronic device constructs a fitting function based on several groups of condensate throttling flows under 100% THA conditions and the output power increment of the dynamic model, then the fitting function represents the functional relationship between the condensate throttling flow under 100% THA conditions and the output power increment of the dynamic model. The electronic device constructs a fitting function based on several groups of condensate throttling flows under 75% THA conditions and the output power increment of the dynamic model, then the fitting function represents the functional relationship between the condensate throttling flow under 75% THA conditions and the output power increment of the dynamic model.

[0066] Step 500: Perform dynamic characteristic analysis of the output power of the dynamic model during condensate throttling based on the fitting function.

[0067] On the basis of obtaining the fitting function, the condensate water saving flow under different operating conditions is input into the fitting function, and the output power increment corresponding to the condensate water saving flow under different operating conditions can be obtained. Thus, the output power increment range of the unit under all conditions can be obtained. By calculating the derivative of the output power increment with respect to time, the power regulation rate of the coal-fired unit during the primary frequency regulation can be obtained. Thus, guidance can be provided for the frequency regulation of the power grid and the regulation of the power plant, and the effect of the frequency regulation of the power grid and the regulation of the power plant can be improved.

[0068] The dynamic model of the coal-fired unit constructed based on the Modelica language in the embodiment of the present invention is applicable to various types of steam turbine systems and has high applicability and reusability. In addition, the fitting function of the embodiment of the present invention characterizes the functional relationship between the condensate throttling amount and the output power increment of the dynamic model under different operating conditions, and realizes the dynamic characteristic analysis of the output power in the process of condensate throttling regulation under all operating conditions, thereby improving the effect of power grid frequency regulation and power plant regulation.

[0069] In other aspects of the embodiments of the present invention, step 400, constructing a fitting function based on the condensate saving amount and adjustment time under the different operating conditions, and the output power under the different operating conditions, includes: Step 410: Determine the output power increment corresponding to the condensate saving flow under different operating conditions based on the difference between the output power of the dynamic model at the end of the adjustment time and the output power of the dynamic model at the beginning of the adjustment time.

[0070] Step 420: performing exponential function fitting based on the condensate saving flow under different operating conditions and the output power increment corresponding to the condensate saving flow under the different operating conditions, and using the exponential function as the fitting function.

[0071] Take the power dynamic characteristics of coal-fired units obtained under 100% THA conditions with different condensate throttling rates as an example. Taking the condensate throttling rate of 1023t / h as an example, PID controls the speed of the condensate pump to instantly reduce the condensate flow rate from 1279t / h to 255t / h by 1023t / h, keeping the boiler feed water unchanged. At this time, due to the small amount of water and large amount of steam on the shell side of the regenerative heater, the saturation pressure drops, and the extraction pressure difference of each section of the low-pressure heater drops, resulting in a decrease in the extraction flow rate, and more steam enters the turbine to work. Therefore, from the change in output power at the beginning and end of the adjustment time of the condensate throttling rate of the dynamic model, the output power increment of the condensate throttling rate of 1023t / h under 100% THA conditions can be obtained.

[0072] After obtaining the condensate throttling amount and the output power increment of the unit under the throttling state under different working conditions, the embodiment of the present invention can use an exponential function for fitting. For example, in one embodiment, the exponential function used in the embodiment of the present invention is expressed by the following formula: ; in, A 1. t 1. y 0 represents the preset coefficient respectively; x represents the condensate throttling amount of the dynamic model in the condensate throttling state; y represents the output power increment of the dynamic model.

[0073] For example, in one embodiment, the function parameters and goodness of fit R for 100% THA condition, 75% THA condition and 50% THA condition are: 2 See Table 3 below: Table 3 Working conditions <![CDATA[A1]]> <![CDATA[t1]]> <![CDATA[y0]]> <![CDATA[R2]]> 100%THA -4.304 -760.164 23.232 0.997 75%THA -6.109 -749.845 22.474 0.999 50%THA -5.893 -618.116 17.373 0.999 Please refer to Figure 5 , Figure 5 It is the relationship between the condensate flow rate and the output power increment of the unit under different working conditions in the throttling state. By constructing a fitting function, it is convenient to obtain the output power increment limit or output power increment range of the coal-fired unit under all working conditions.

[0074] In other aspects of the embodiments of the present invention, step 500, performing a dynamic characteristic analysis of the output power of the dynamic model during condensate throttling based on the fitting function, includes: Step 510: input the condensate saving flow under the different operating conditions into the fitting function to obtain the output power increment range of the dynamic model under all operating conditions.

[0075] For example, 1023.43t·h -1 、768.03t·h -1 、512.43t·h -1 、256.83t·h -1 The output power increment range under 100% THA condition can be obtained by inputting the condensate saving flow into the fitting function under 100% THA condition. -1 、481.56t·h -1 、337.56t·h -1 、157.56t·h -1 The output power increment range under 75% THA condition can be obtained by inputting the condensate saving flow into the fitting function under 75% THA condition. -1 、308.12t·h -1 、164.12t·h -1 The fitting function of the condensate water saving flow input under 50% THA condition can obtain the output power increment range under 50% THA condition. Therefore, the embodiment of the present invention obtains the power growth range (or power increment range) of the full condition through the fitting function, which can be used to analyze the flexibility of coal-fired units under deep peak regulation.

[0076] Step 520: obtaining the output power increment corresponding to the condensate water saving flow rate under the target operating condition based on the fitting function, and determining the power regulation rate under the target operating condition based on the output power increment under the target operating condition and the regulation time corresponding to the condensate water saving flow rate under the target operating condition.

[0077] The electronic device obtains the output power increment corresponding to the condensate water saving flow under the target operating condition based on the fitting function. The target operating condition is any one of the operating conditions under the different operating conditions. Then, based on the ratio of the output power increment and the adjustment time corresponding to the condensate water saving flow under the target operating condition, the power adjustment rate under the target operating condition is determined. For example, the condensate water saving flow under the 100% THA condition is 1023.43 t·h -1 The power increment of the dynamic model of the coal-fired unit within 60 seconds is 5.70MW, so the power regulation rate can be calculated to be 5.70 / 60=0.95MW·min -1 .

[0078] At the same time, the power regulation rate of the coal-fired unit obtained by adopting the condensate throttling scheme under different working conditions in the embodiment of the present invention is shown in Table 4 below: Table 4

[0079] In other aspects of the embodiments of the present invention, the method further includes: Step 600: Calculate the dynamic exergy of each component based on the enthalpy value, entropy value and temperature value of each component in the dynamic model, and calculate the exergy loss of each component based on the input exergy flow and output exergy flow of each component.

[0080] The electronic device calculates the dynamic exergy of each component based on the enthalpy, entropy and temperature of each component in the dynamic model under the throttling state, and calculates the exergy loss of each component based on the input exergy and output exergy of each component. The dynamic exergy and exergy loss of the condensate water throttling amount of 256.83 t / h under 100% THA operating conditions are analyzed as an example. The electronic device obtains the enthalpy, entropy and temperature of each component in the dynamic model, and uses the following formula to calculate the dynamic exergy of the corresponding position.

[0081] ; In the above formula: H , H 0 represents the enthalpy of the system in a given state and the ambient reference state, kJ / s; S , S 0 represents the entropy of the system in a given state and the reference state of the environment, kJ / (K·s); T 0 represents the temperature under the ambient reference state (100 kPa), which is 298.15K. E Indicates dynamic exergy.

[0082] When calculating the dynamic exergy losses of various components in a coal-fired unit, the following exergy balance model is adopted.

[0083] ; In the above formula: E in represents the input exergy, kJ / s; E out represents the output exergy, kJ / s; E x represents exergy loss, kJ / s. In one embodiment, Figure 6-Figure 9 It is the dynamic input exergy and output exergy of each level of low-pressure heater (1# low-pressure heater, 2# low-pressure heater, 3# low-pressure heater, 4# low-pressure heater) in the low-pressure heater group in the embodiment of the present invention. Fig.10 It is the dynamic exergy loss process of each level of low-pressure heating (1# low-pressure heating, 2# low-pressure heating, 3# low-pressure heating, 4# low-pressure heating).

[0084] It should be noted that step 600 may be located after step 500 or after step 400 .

[0085] The embodiment of the present invention uses the Modelica language to establish a dynamic model of a steam turbine system, which includes equipment such as a steam turbine body, a high (low) pressure heater, a deaerator, a condenser, and a water pump. After completing the dynamic modeling of the system, based on a certain operating condition, the initial values ​​of parameters such as the main steam and reheat steam parameters and the condensate flow rate are obtained. Subsequently, the speed of the condensate pump and the feed water pump are adjusted by PID control to achieve the set condensate throttling amount and throttling time. The dynamic characteristics of the internal parameters and output power of the coal-fired unit during the adjustment process are analyzed; finally, the power growth range of the coal-fired unit under full operating conditions, the dynamic exergy of each logistics, and the dynamic exergy loss of the components are obtained. The embodiment of the present invention can be applied to multiple types of steam turbine systems, and takes into account the power growth limit of the unit under full operating conditions and the dynamic exergy and exergy loss of each component. The embodiment of the present invention can obtain the power increment range of the condensate throttling method under all operating conditions of the unit; can calculate the output power of each cylinder and the steam parameters of the corresponding steam extraction port during the throttling process; analyze the energy consumption of the steam turbine during the condensate throttling process from the perspective of dynamic exergy and exergy loss; and obtain the maximum adjustable time of condensate throttling.

[0086] Device Embodiment Please refer to Fig.11 On the other hand, an embodiment of the present invention further provides a condensate throttling process analysis device for a coal-fired unit, comprising: A construction module 1101 is used to construct a dynamic model of a coal-fired unit based on the Modelica language; An acquisition module 1102 is used to acquire the condensate water saving amount and adjustment time under different operating conditions; A calculation module 1103, used to input the condensate saving amount and the adjustment time under the different operating conditions into the dynamic model respectively, to obtain the output power of the dynamic model under all operating conditions; A fitting module 1104 is used to construct a fitting function based on the condensate water saving flow and adjustment time under the different operating conditions and the output power under all operating conditions; the fitting function represents the functional relationship between the condensate water saving flow and the output power increment of the dynamic model; The first analysis module 1105 is used to perform a dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function.

[0087] Optionally, constructing a fitting function based on the condensate water saving amount and adjustment time under the different operating conditions and the output power under the different operating conditions includes: Determine the output power increment corresponding to the condensate water saving amount under different operating conditions based on the difference between the output power of the dynamic model at the end of the adjustment time and the output power of the dynamic model at the beginning of the adjustment time; An exponential function is fitted based on the condensate saving flow under different operating conditions and the output power increment corresponding to the condensate saving flow under the different operating conditions, and the exponential function is used as the fitting function.

[0088] Optionally, the exponential function is expressed by the following formula: ; in, A 1. t 1. y 0 represents the preset coefficient respectively; x represents the condensate throttling amount of the dynamic model in the condensate throttling state; y represents the output power increment of the dynamic model.

[0089] Optionally, the performing the dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function includes: Inputting the condensate saving amount under the different operating conditions into the fitting function to obtain the output power increment range of the dynamic model under all operating conditions; The output power increment corresponding to the condensate water saving flow under the target operating condition is obtained based on the fitting function, and the power regulation rate under the target operating condition is determined based on the output power increment under the target operating condition and the regulation time corresponding to the condensate water saving flow under the target operating condition; wherein the target operating condition is any one of the different operating conditions.

[0090] Optionally, the device further comprises: The second analysis module is used to calculate the dynamic exergy of each component based on the enthalpy value, entropy value and temperature value of each component in the dynamic model, and calculate the exergy loss of each component based on the input exergy flow and output exergy flow of each component.

[0091] The condensate throttling process analysis device of the coal-fired unit includes a processor and a memory. The above-mentioned construction module 1101, acquisition module 1102, calculation module 1103, fitting module 1104 and first analysis module 1105 are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to realize corresponding functions.

[0092] The processor includes a kernel, which calls the corresponding program unit from the memory. There can be one or more kernels.

[0093] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0094] Fig.12 An example of a physical structure diagram of an electronic device is shown in FIG. Fig.12 As shown, the electronic device may include: a processor (processor) 1210, a communication interface (Communications Interface) 1220, a memory (memory) 1230 and a communication bus 1240, wherein the processor 1210, the communication interface 1220, and the memory 1230 communicate with each other through the communication bus 1240. The processor 1210 can call the logic instructions in the memory 1230 to execute the condensate throttling process analysis method of the coal-fired unit, which method includes: constructing a dynamic model of the coal-fired unit based on the Modelica language; obtaining the condensate throttling amount and adjustment time under different operating conditions; inputting the condensate throttling amount and adjustment time under the different operating conditions into the dynamic model respectively to obtain the output power of the dynamic model under all operating conditions; constructing a fitting function based on the condensate throttling amount and adjustment time under the different operating conditions, and the output power under all operating conditions; the fitting function characterizes the functional relationship between the condensate throttling amount and the output power increment of the dynamic model; based on the fitting function, performing a dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process.

[0095] In addition, the logic instructions in the above-mentioned memory 1230 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0096] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a machine-readable storage medium. When the computer program is executed by a processor, the computer can execute a condensate throttling process analysis method for a coal-fired unit, the method including: constructing a dynamic model of the coal-fired unit based on the Modelica language; obtaining the condensate throttling amount and adjustment time under different operating conditions; inputting the condensate throttling amount and adjustment time under the different operating conditions into the dynamic model respectively to obtain the output power of the dynamic model under all operating conditions; constructing a fitting function based on the condensate throttling amount and adjustment time under the different operating conditions, and the output power under all operating conditions; the fitting function characterizes the functional relationship between the condensate throttling amount and the output power increment of the dynamic model; and performing a dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function.

[0097] On the other hand, the present invention also provides a machine-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute a condensate throttling process analysis method for a coal-fired unit, the method comprising: constructing a dynamic model of the coal-fired unit based on the Modelica language; obtaining the condensate throttling amount and adjustment time under different operating conditions; inputting the condensate throttling amount and adjustment time under the different operating conditions into the dynamic model respectively to obtain the output power of the dynamic model under all operating conditions; constructing a fitting function based on the condensate throttling amount and adjustment time under the different operating conditions, and the output power under all operating conditions; the fitting function characterizes the functional relationship between the condensate throttling amount and the output power increment of the dynamic model; and performing a dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function.

[0098] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0099] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0100] 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 embodiments of the present invention.

Claims

1. A method for analyzing the condensate throttling process of a coal-fired unit, characterized in that: include: Construct the dynamic model of coal-fired units based on Modelica language; Obtain condensate water saving volume and adjustment time under different operating conditions; Inputting the condensate water saving amount and the adjustment time under the different operating conditions into the dynamic model respectively, and obtaining the output power of the dynamic model under all operating conditions; A fitting function is constructed based on the condensate water saving amount and the adjustment time under the different operating conditions, and the output power under all operating conditions; the fitting function represents the functional relationship between the condensate water saving amount and the output power increment of the dynamic model; The dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process is performed based on the fitting function.

2. The condensate throttling process analysis method of a coal-fired unit according to claim 1, characterized in that: The constructing of a fitting function based on the condensate water saving amount and the adjustment time under the different operating conditions and the output power under the different operating conditions includes: Determine the output power increment corresponding to the condensate water saving amount under different operating conditions based on the difference between the output power of the dynamic model at the end of the adjustment time and the output power of the dynamic model at the beginning of the adjustment time; An exponential function is fitted based on the condensate saving flow under different operating conditions and the output power increment corresponding to the condensate saving flow under the different operating conditions, and the exponential function is used as the fitting function.

3. The condensate throttling process analysis method of a coal-fired unit according to claim 2, characterized in that: The exponential function is expressed by the following formula: ； in, A 1. t 1. y 0 represents the preset coefficient respectively; x represents the condensate throttling amount of the dynamic model in the condensate throttling state; y represents the output power increment of the dynamic model.

4. The condensate throttling process analysis method of a coal-fired unit according to claim 1, characterized in that: The dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function includes: Inputting the condensate saving amount under the different operating conditions into the fitting function to obtain the output power increment range of the dynamic model under all operating conditions; The output power increment corresponding to the condensate water saving flow under the target operating condition is obtained based on the fitting function, and the power regulation rate under the target operating condition is determined based on the output power increment under the target operating condition and the regulation time corresponding to the condensate water saving flow under the target operating condition; wherein the target operating condition is any one of the different operating conditions.

5. The condensate throttling process analysis method of a coal-fired unit according to claim 1, characterized in that: The method further comprises: The dynamic exergy of each component is calculated based on the enthalpy value, entropy value and temperature value of each component in the dynamic model, and the exergy loss of each component is calculated based on the input exergy and output exergy of each component.

6. A condensate throttling process analysis device for a coal-fired unit, characterized in that: include: Building module for building dynamic models of coal-fired units based on Modelica language; An acquisition module is used to obtain the condensate water saving amount and adjustment time under different operating conditions; A calculation module, used for inputting the condensate water saving amount and the adjustment time under the different operating conditions into the dynamic model respectively, and obtaining the output power of the dynamic model under all operating conditions; A fitting module, used to construct a fitting function based on the condensate water saving flow and adjustment time under the different operating conditions, and the output power under all operating conditions; the fitting function represents the functional relationship between the condensate water saving flow and the output power increment of the dynamic model; The first analysis module is used to perform a dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function.

7. The condensate throttling process analysis device for a coal-fired unit according to claim 6, characterized in that: The constructing of a fitting function based on the condensate water saving amount and the adjustment time under the different operating conditions and the output power under the different operating conditions includes: Determine the output power increment corresponding to the condensate water saving amount under different operating conditions based on the difference between the output power of the dynamic model at the end of the adjustment time and the output power of the dynamic model at the beginning of the adjustment time; An exponential function is fitted based on the condensate saving flow under different operating conditions and the output power increment corresponding to the condensate saving flow under the different operating conditions, and the exponential function is used as the fitting function.

8. The condensate throttling process analysis device for a coal-fired unit according to claim 7, characterized in that: The exponential function is expressed by the following formula: ； in, A 1. t 1. y 0 represents the preset coefficient respectively; x represents the condensate throttling amount of the dynamic model in the condensate throttling state; y represents the output power increment of the dynamic model.

9. The condensate throttling process analysis device for a coal-fired unit according to claim 6, characterized in that: The dynamic characteristic analysis of the output power of the dynamic model during the condensate throttling process based on the fitting function includes: Inputting the condensate saving amount under the different operating conditions into the fitting function to obtain the output power increment range of the dynamic model under all operating conditions; The output power increment corresponding to the condensate water saving flow under the target operating condition is obtained based on the fitting function, and the power regulation rate under the target operating condition is determined based on the output power increment under the target operating condition and the regulation time corresponding to the condensate water saving flow under the target operating condition; wherein the target operating condition is any one of the different operating conditions.

10. The condensate throttling process analysis device for a coal-fired unit according to claim 6, characterized in that: The device also includes: The second analysis module is used to calculate the dynamic exergy of each component based on the enthalpy value, entropy value and temperature value of each component in the dynamic model, and calculate the exergy loss of each component based on the input exergy flow and output exergy flow of each component.

11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the condensate throttling process analysis method of the coal-fired unit described in any one of claims 1 to 5 is implemented.

12. A machine-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the condensate throttling process analysis method of a coal-fired unit according to any one of claims 1 to 5 is implemented.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the condensate throttling process analysis method of a coal-fired unit according to any one of claims 1 to 5 is implemented.

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