Natural circulation boiler water-cooled wall thermal load deviation coefficient coupling calculation method and device

Abstract

The invention discloses a coupling calculation method and device for a thermal load deviation coefficient of a water-cooled wall of a natural circulation boiler, and the method comprises the steps: carrying out the temperature numerical simulation calculation of a measurement point position through employing the working medium temperature, the initial thermal load and a convective heat transfer coefficient at the measurement point position as initial boundary conditions; comparing the temperature numerical simulation calculation result with the actual temperature of the measuring point position, and if the absolute value of the difference value is not less than a preset deviation threshold value, changing the thermal load in the boundary condition, and then performing temperature numerical simulation calculation on the measuring point position again until the absolute value of the difference value is less than the preset deviation threshold value. Outputting the thermal load in the current boundary condition, wherein the thermal load is the thermal load of the real furnace at the measuring point position; comparing the real furnace thermal load of the measuring point position with the theoretical thermal load of the measuring point position to obtain a real furnace thermal load deviation value of the measuring point position; fitting the thermal load deviation values of the real boiler at the positions of the plurality of measuring points at the same height to obtain a thermal load deviation distribution curve of the real boiler of the water cooling wall of the natural circulation boiler. The invention aims to realize the calculation of the thermal load deviation coefficient of the water-cooled wall of the natural circulation boiler.

Description

Technical Field

[0001] The present invention belongs to the technical field of boiler power generation, and particularly relates to a coupled calculation method and device for the thermal load deviation coefficient of the water-cooled wall of a natural circulation boiler. Background Art

[0002] In order to address global climate change and reduce carbon dioxide emissions, many countries and regions are promoting energy transformation and the development of clean energy. Wind power generation, photovoltaic power generation, etc. in the power system are characterized by uncertainty and intermittency, with large fluctuations. With the large-scale introduction and development of renewable energy sources (such as wind energy and solar energy), the impact of renewable energy sources such as wind power and photovoltaic power on the power grid is increasing. In order to achieve stable power supply of renewable energy, it is necessary for power station boilers to perform peak shaving to bridge the gap between the power generation of renewable energy and the grid load.

[0003] In power station boilers, the research on the hydrodynamic characteristics of the water-cooled wall of a subcritical natural circulation boiler is one of the key technologies to ensure the stable and safe operation of the boiler, and is of great significance for the optimal design of the water-cooled wall and the safe and reliable operation of the boiler. If the water circulation of a natural circulation boiler is abnormal, it often causes the metal tube walls of the evaporative heating surface to not be sufficiently cooled and heat up, resulting in a reduction in strength, or the heating surface being corroded and thinned, and finally leading to a tube burst accident, making it difficult for the boiler to operate reliably for a long time. For a natural circulation boiler with variable low load, the above problems are more likely to occur. Therefore, it is necessary to perform hydrodynamic characteristic calculations. To accurately calculate the hydrodynamic characteristics of the boiler water-cooled wall, it is necessary to calculate the actual thermal load deviation distribution along the furnace width direction.

[0004] The patent with the publication number CN118194591A discloses a calculation method for the thermal load deviation coefficient of a boiler water-cooled wall, which performs iterative calculation of the thermal load deviation coefficient of the water-cooled wall by determining whether the error between the theoretical outlet steam temperature of each loop and the measured outlet steam temperature of each loop is less than a set value. For a non-natural circulation boiler, this method can accurately obtain the thermal load deviation coefficient of the boiler water-cooled wall. However, since the working medium at the outlet of the water-cooled wall tube of a natural circulation boiler is in the two-phase region, and its outlet working medium temperature is the saturation temperature (that is, the difference between the measured outlet steam temperature of each loop and the theoretical outlet steam temperature is very close, generally not exceeding 3°C), this results in the inability to calculate the thermal load deviation coefficient of the water-cooled wall through iterative calculation, that is, this method cannot achieve the calculation of the thermal load deviation coefficient of the water-cooled wall of a natural circulation boiler. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a coupled calculation method and device for the thermal load deviation coefficient of the water-cooled wall of a natural circulation boiler, aiming to achieve the calculation of the thermal load deviation coefficient of the water-cooled wall of a natural circulation boiler.

[0006] To solve the above technical problems, the present invention is achieved through the following technical solutions:

[0007] According to a first aspect of the present invention, there is provided a coupled calculation method for the thermal load deviation coefficient of the water-cooled wall of a natural circulation boiler, including:

[0008] Obtain the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water-cooled wall, the measured outlet steam temperature of each circuit, and the actual temperature at the measuring point position on the water-cooled wall surface;

[0009] Perform water-cooled wall hydrodynamic calculation according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water-cooled wall, the measured outlet steam temperature of each circuit, and the preset thermal load deviation coefficient of each circuit, to obtain the working medium temperature, initial thermal load, and convective heat transfer coefficient at the measuring point position;

[0010] Take the working medium temperature, initial thermal load, and convective heat transfer coefficient at the measuring point position as the initial boundary conditions, perform temperature numerical simulation calculation on the measuring point position, compare the temperature numerical simulation calculation result with the actual temperature at the measuring point position. If the absolute value of the difference between the two is not less than the preset deviation threshold, then after changing the thermal load in the boundary conditions, re-perform temperature numerical simulation calculation on the measuring point position until the absolute value of the difference is less than the preset deviation threshold, and output the thermal load in the current boundary conditions. This thermal load is the actual furnace thermal load at the measuring point position;

[0011] Compare the actual furnace thermal load at the measuring point position with the theoretical thermal load at the measuring point position to obtain the actual furnace thermal load deviation value at the measuring point position;

[0012] Fit the actual furnace thermal load deviation values at multiple measuring point positions at the same height to obtain the actual furnace thermal load deviation distribution curve of the water-cooled wall of the natural circulation boiler.

[0013] In a possible implementation manner of the first aspect, the measuring point positions are arranged at the back-fire side fin tips, fin roots, back-fire side vertices, and / or the fire side on the finned tubes of the water-cooled wall.

[0014] In a possible implementation manner of the first aspect, the performing water-cooled wall hydrodynamic calculation according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water-cooled wall, the measured outlet steam temperature of each circuit, and the preset thermal load deviation coefficient of each circuit is specifically:

[0015] Adopt the flow grid system method to perform water-cooled wall hydrodynamic calculation according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water-cooled wall, the measured outlet steam temperature of each circuit, and the preset thermal load deviation coefficient of each circuit.

[0016] In a possible implementation manner of the first aspect, the taking the working medium temperature, initial thermal load, and convective heat transfer coefficient at the measuring point position as the initial boundary conditions and performing temperature numerical simulation calculation on the measuring point position is specifically:

[0017] An Ansys Workbench two-dimensional steady-state thermal analysis model is adopted. Based on the temperature-dependent thermophysical properties of the water-cooled wall material of the natural circulation boiler, as well as the working fluid temperature, initial heat load, and convective heat transfer coefficient at the measuring point position as the initial boundary conditions, mesh generation and boundary condition setting are carried out. After the mesh generation and boundary condition setting are completed, the temperature numerical simulation calculation can be performed at the measuring point position.

[0018] In a possible implementation manner of the first aspect, the boundary condition setting is specifically as follows:

[0019]

[0020] In the formula, t w is the metal temperature of the water-cooled wall tube, °C; t f is the working fluid temperature, °C; λ is the thermal conductivity of the water-cooled wall material, W / (m·°C); h is the convective heat transfer coefficient on the inner wall of the water-cooled wall tube, W / (m 2 ·°C); q(x) is the heat flux density function on the outer wall of the water-cooled wall tube facing the fire side, W / m 2 ; is the second partial derivative of the water-cooled wall temperature t in the x direction, and the x direction is along the width direction of the water-cooled wall; is the second partial derivative of the water-cooled wall temperature t in the y direction, and the y direction is perpendicular to the wall surface of the water-cooled wall; is the temperature change rate of the outer wall of the water-cooled wall tube facing the fire side, and n is the normal direction of the water-cooled wall surface; is the temperature change rate of the inner wall of the water-cooled wall tube; is the temperature change rate at other positions of the water-cooled wall; q0 is the heat load on the wall surface of the water-cooled wall, W / m 2 ; is the angle coefficient function of the water-cooled wall facing the fire side to the tube wall and fins.

[0021] In a possible implementation manner of the first aspect, the fitting of the actual furnace heat load deviation values at multiple measuring point positions at the same height is specifically as follows:

[0022] Based on the least squares method or polynomial regression algorithm, the actual furnace heat load deviation values at multiple measuring point positions at the same height are fitted.

[0023] According to the second aspect of the present invention, a coupling calculation device for the heat load deviation coefficient of the water-cooled wall of a natural circulation boiler is provided, including:

[0024] An acquisition module for acquiring the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water-cooled wall, the measured outlet steam temperature of each loop, and the actual temperature at the measuring point position on the wall surface of the water-cooled wall;

[0025] A hydrodynamic meter module is used to perform hydrodynamic calculation of the water wall according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperatures of each loop, and the preset heat load deviation coefficients of each loop, so as to obtain the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position;

[0026] An iteration module is used to use the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position as initial boundary conditions to perform temperature numerical simulation calculation on the measuring point position, compare the temperature numerical simulation calculation result with the actual temperature at the measuring point position. If the absolute value of the difference between the two is not less than the preset deviation threshold, after changing the heat load in the boundary conditions, re-perform temperature numerical simulation calculation on the measuring point position until the absolute value of the difference is less than the preset deviation threshold, and output the heat load in the current boundary conditions. This heat load is the actual furnace heat load at the measuring point position;

[0027] A ratio module is used to compare the actual furnace heat load at the measuring point position with the theoretical heat load at the measuring point position to obtain the actual furnace heat load deviation value at the measuring point position;

[0028] A fitting module is used to fit the actual furnace heat load deviation values at multiple measuring point positions at the same height to obtain the actual furnace heat load deviation distribution curve of the water wall of the natural circulation boiler.

[0029] According to the third aspect of the present invention, there is provided a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for coupling the heat load deviation coefficient of the water wall of a natural circulation boiler as described above.

[0030] According to the fourth aspect of the present invention, there is provided a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method for coupling the heat load deviation coefficient of the water wall of a natural circulation boiler as described above.

[0031] According to the fifth aspect of the present invention, there is provided a computer program product. When the computer program product is executed by a processor, it implements the method for coupling the heat load deviation coefficient of the water wall of a natural circulation boiler as described above.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] A coupled calculation method for the heat load deviation coefficient of the water-cooled wall of a natural circulation boiler provided by the present invention aims at the problem that the working medium temperature at the outlet of the water-cooled wall of a natural circulation boiler is the saturation temperature, and it is difficult to determine the heat load deviation coefficient through iterative calculation. By taking the working medium temperature, the initial heat load, and the convective heat transfer coefficient at the measuring point position as the initial boundary conditions, the temperature numerical simulation calculation is carried out for the measuring point position. The result of the temperature numerical simulation calculation is compared with the actual temperature at the measuring point position. If the absolute value of the difference between the two is not less than the preset deviation threshold, after changing the heat load in the boundary conditions, the temperature numerical simulation calculation is carried out again for the measuring point position until the absolute value of the difference is less than the preset deviation threshold, and then the heat load in the current boundary conditions is output, and this heat load is the actual furnace heat load at the measuring point position; the actual furnace heat load at the measuring point position is compared with the theoretical heat load at the measuring point position to obtain the actual furnace heat load deviation value at the measuring point position. Finally, the actual furnace heat load deviation values at multiple measuring point positions at the same height are fitted to obtain the actual furnace heat load deviation distribution curve of the water-cooled wall of the natural circulation boiler. It can be seen that this method does not need to rely on the iterative judgment of the outlet steam temperature, but judges whether it is necessary to change the heat load and continue the iterative calculation by comparing the result of the temperature numerical simulation calculation with the actual temperature, realizing the accurate calculation of the heat load deviation coefficient of the water-cooled wall of the natural circulation boiler, filling the technical gap in this field. By accurately calculating the heat load deviation coefficient of the water-cooled wall of the natural circulation boiler, it is beneficial to the design of the water-cooled wall of the natural circulation boiler, ensuring that the water-cooled wall tubes are sufficiently cooled and avoiding problems such as strength reduction or thinning of the heating surface due to excessive temperature.

[0034] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following will briefly introduce the drawings required for use in the description of the specific embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a flowchart of a coupled calculation method for the heat load deviation coefficient of the water-cooled wall of a natural circulation boiler of the present invention;

[0037] Figure 2 It is a schematic diagram of the measuring point position of the water-cooled wall provided by the embodiment of the present invention;

[0038] Figure 3 It is a structural diagram of a membrane water-cooled wall tube provided by the embodiment of the present invention;

[0039] Figure 4It is a schematic diagram of the grid of the water wall cross-section provided by the embodiment of the present invention. Specific embodiments

[0040] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] As Figure 1 shown, a coupling calculation method for the thermal load deviation coefficient of the water wall of a natural circulation boiler provided by the embodiment of the present invention is mainly to solve the problem that the thermal load deviation coefficient of the water wall of a natural circulation boiler cannot be accurately calculated in the prior art. The specific steps are as follows:

[0042] S1. Obtain the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the actual temperature at the measuring point positions on the water wall surface.

[0043] Specifically, use a flow meter to measure the cooling water flow rate of each loop of the water wall; install pressure sensors at the inlet and outlet of the water wall to record the pressure values at the inlet and outlet respectively; obtain the enthalpy values of the working medium at the inlet and outlet of the water wall through an enthalpy measuring device; install temperature sensors at the outlets of each loop to record the measured outlet steam temperature of each loop. At the same time, install temperature sensors at the preset measuring point positions on the water wall surface to record the actual temperatures at these positions.

[0044] S2. Perform water wall hydrodynamic calculations based on the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the preset thermal load deviation coefficients of each loop to obtain the working medium temperature, initial thermal load, and convective heat transfer coefficient at the measuring point positions.

[0045] That is to say, after collecting the above data, use these data and the preset thermal load deviation coefficients of each loop to perform hydrodynamic calculations on the water wall, aiming to obtain the working medium temperature, initial thermal load, and convective heat transfer coefficient at the measuring point positions.

[0046] S3. Take the working medium temperature, initial thermal load, and convective heat transfer coefficient at the measuring point positions as the initial boundary conditions, perform temperature numerical simulation calculations on the measuring point positions, compare the temperature numerical simulation calculation results with the actual temperature at the measuring point positions. If the absolute value of the difference between the two is not less than the preset deviation threshold, then after changing the thermal load in the boundary conditions, re-perform temperature numerical simulation calculations on the measuring point positions until the absolute value of the difference is less than the preset deviation threshold, and output the thermal load in the current boundary conditions. This thermal load is the actual furnace thermal load at the measuring point positions.

[0047] That is to say, next, the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position are used as the initial boundary conditions, and a numerical simulation software is used to perform numerical simulation calculations on the temperature at the measuring point position. The simulation results need to be compared with the actual temperature at the measuring point position. If the absolute value of the difference between the two is not less than the preset deviation threshold (for example, ±1 °C or other values set according to specific requirements), it is considered that the simulation results are not accurate enough, and the heat load value in the boundary conditions needs to be adjusted, and the numerical simulation calculations are performed again. This process will be iterated until the absolute value of the difference between the simulation results and the actual temperature is less than the preset deviation threshold. At this time, the heat load value in the current boundary conditions is output, and this value is the actual furnace heat load at the measuring point position.

[0048] S4. Compare the actual furnace heat load at the measuring point position with the theoretical heat load at the measuring point position to obtain the actual furnace heat load deviation value at the measuring point position.

[0049] Specifically, after obtaining the actual furnace heat load at the measuring point position, it is compared with the theoretical heat load at the same measuring point position. It should be understood that the theoretical heat load can be obtained through heat load calculation formulas, empirical formulas, or the theoretical heat load curve provided in the boiler instruction manual. Divide the actual furnace heat load by the theoretical heat load, and the result obtained is the actual furnace heat load deviation value at the measuring point position.

[0050] S5. Fit the actual furnace heat load deviation values at multiple measuring point positions at the same height to obtain the actual furnace heat load deviation distribution curve of the water-cooled wall of the natural circulation boiler.

[0051] That is to say, perform fitting processing on the actual furnace heat load deviation values at multiple measuring point positions at the same height. The result of the fitting is a curve representing the actual furnace heat load deviation distribution of the water-cooled wall of the natural circulation boiler. This curve can intuitively understand the heat load deviation situation of the water-cooled wall along the furnace width direction, thereby providing a reference for the optimal design and safe operation of the boiler.

[0052] In one realizable manner, the measuring point positions are arranged at the fin tips, fin roots, back-fire side vertices, and / or fire side of the water-cooled wall finned tubes.

[0053] That is to say, the measuring point positions are not limited to a specific position of the water-cooled wall tube, but are arranged at multiple key positions on the water-cooled wall finned tubes, including the fin tips, fin roots, back-fire side vertices, and / or fire side. These positions are highly sensitive to changes in heat load and can more comprehensively reflect the heat load deviation situation of the water-cooled wall.

[0054] Exemplarily, such as Figure 2As shown in the figure, 4 thermocouple measurement points are arranged at one measurement point location, which are respectively located at the fin tip A on the back-fire side of the water-cooled wall finned tube, the fin root B, the back-fire side vertex C, and the fire-side D. For the specific positions, please refer to Figure 2 . It should be noted that the specific number of thermocouple measurement points at one measurement point location depends on the specific situation of the furnace.

[0055] In one implementable manner, the flow grid system method is adopted to perform the hydrodynamic calculation of the water-cooled wall according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water-cooled wall, the measured outlet steam temperatures of each loop, and the preset heat load deviation coefficients of each loop.

[0056] It should be noted that the specific implementation process of the flow grid system method can refer to the content of the patent specification with the publication number CN106897547A, and will not be elaborated here.

[0057] In one implementable manner, the working medium temperature, initial heat load, and convective heat transfer coefficient at the measurement point location are used as the initial boundary conditions to perform the temperature numerical simulation calculation at the measurement point location. Specifically:

[0058] An Ansys Workbench two-dimensional steady-state thermal analysis model is adopted, and based on the temperature-dependent thermophysical properties of the water-cooled wall material of the natural circulation boiler, as well as the working medium temperature, initial heat load, and convective heat transfer coefficient at the measurement point location as the initial boundary conditions, mesh generation and boundary condition setting are carried out. After the mesh generation and boundary condition setting are completed, the temperature numerical simulation calculation can be performed at the measurement point location.

[0059] That is to say, Ansys Workbench is selected as the numerical simulation software, and its two-dimensional steady-state thermal analysis model is used to perform the temperature numerical simulation calculation. According to the actual structure and size of the water-cooled wall, a two-dimensional steady-state thermal analysis model is established. The two-dimensional steady-state thermal analysis model should include key elements such as water-cooled wall pipes, fins, and measurement points. Consider the temperature-dependent thermophysical properties of the water-cooled wall material of the natural circulation boiler, such as thermal conductivity, elastic modulus, linear expansion coefficient, and yield strength, etc. These properties will change with the change of temperature and need to be set according to specific material data. Mesh generation is performed on the model to ensure that the mesh quality meets the calculation requirements. The working medium temperature, initial heat load, and convective heat transfer coefficient at the measurement point location are used as the initial boundary conditions and input into the model. At the same time, according to the actual operating conditions of the water-cooled wall, reasonable external boundary conditions, such as convective heat transfer coefficient, etc., are set. Finally, Ansys Workbench is started for calculation to obtain the temperature distribution result at the measurement point location.

[0060] The boundary condition setting is specifically as follows:

[0061]

[0062] In the formula, tw is the metal temperature of the water wall tube wall, in °C; t f is the working fluid temperature, in °C; λ is the thermal conductivity of the water wall material, in W / (m·°C); h is the convective heat transfer coefficient on the inner wall of the water wall tube, in W / (m 2 ·°C); q(x) is the heat flux density function on the outer wall of the water wall tube facing the fire, in W / m 2 ; is the second partial derivative of the water wall temperature t in the x direction, where the x direction is along the width direction of the water wall; is the second partial derivative of the water wall temperature t in the y direction, where the y direction is perpendicular to the wall surface of the water wall; is the temperature change rate of the outer wall of the water wall tube facing the fire, and n is the normal direction of the water wall surface; is the temperature change rate of the inner wall of the water wall tube; is the temperature change rate at other positions of the water wall; q0 is the heat load on the water wall surface, in W / m 2 ; is the angular coefficient function of the water wall facing the fire for the tube wall and fins, which can be calculated according to the literature "Solution of the Radiation Angular Coefficient of Rectangular Fin Membrane Water Wall".

[0063] Exemplarily, the water wall material BS3059 243 of the natural circulation boiler is regarded as an isotropic material, and the magnitude of the thermal conductivity is only related to the temperature change. The specific thermophysical properties are shown in Table 1.

[0064] Table 1 Thermophysical Properties of Water Wall Material

[0065]

[0066] Adopt the two-dimensional steady-state thermal analysis model in Ansys Workbench to model it and conduct mesh division. The specific structure of the membrane water wall can be seen in Figure 2 , and the mesh division diagram can be seen in Figure 3 . Figure 2 In the outer wall of the water wall tube facing the fire in is AEG, the inner wall of the water wall tube in

[0067] In one implementable way, based on the least squares method or polynomial regression algorithm, the real furnace heat load deviation values at multiple measurement point positions at the same height are fitted.

[0068] Specifically, the actual furnace heat load deviation values at multiple measuring point positions at the same height are input into the fitting algorithm for fitting calculation. After obtaining the fitting function, the heat load deviation distribution curve can be plotted.

[0069] Preferably, after obtaining the actual furnace heat load deviation distribution curve of the water wall of the natural circulation boiler, the actual furnace heat load deviation coefficients of each loop are obtained according to the actual furnace heat load deviation distribution curve. After replacing the preset heat load deviation coefficients of each loop in step S2 with the actual furnace heat load deviation coefficients of each loop, the water wall hydrodynamic calculation is performed to obtain the working medium temperature, heat load, and convective heat transfer coefficient at the measuring point position. Taking the working medium temperature, heat load, and convective heat transfer coefficient at the measuring point position as boundary conditions, the temperature numerical simulation calculation is carried out for the measuring point position, and the result of the temperature numerical simulation calculation is compared with the actual temperature at the measuring point position. After verification, if the absolute value of the difference between the two is less than the preset deviation threshold, it indicates that the actual furnace heat load deviation distribution curve is reliable, and the actual furnace heat load deviation distribution curve is output; otherwise, S3 is performed again.

[0070] In another embodiment of the present invention, a coupling calculation device for the heat load deviation coefficient of the water wall of a natural circulation boiler is provided, including:

[0071] An acquisition module for acquiring the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the actual temperature at the measuring point position on the water wall surface.

[0072] A hydrodynamic calculation module for performing water wall hydrodynamic calculation according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the preset heat load deviation coefficients of each loop to obtain the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position.

[0073] An iteration module for taking the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position as initial boundary conditions, performing temperature numerical simulation calculation for the measuring point position, comparing the result of the temperature numerical simulation calculation with the actual temperature at the measuring point position. If the absolute value of the difference between the two is not less than the preset deviation threshold, after changing the heat load in the boundary conditions, the temperature numerical simulation calculation is performed again for the measuring point position until the absolute value of the difference is less than the preset deviation threshold, and the heat load in the current boundary conditions is output, and this heat load is the actual furnace heat load at the measuring point position.

[0074] A ratio module for comparing the actual furnace heat load at the measuring point position with the theoretical heat load at the measuring point position to obtain the actual furnace heat load deviation value at the measuring point position.

[0075] A fitting module, configured to fit the actual furnace heat load deviation values at multiple measuring point positions at the same height to obtain the actual furnace heat load deviation distribution curve of the water wall of a natural circulation boiler.

[0076] All relevant contents of each step involved in the embodiment of the foregoing method for coupling and calculating the heat load deviation coefficient of the water wall of a natural circulation boiler can be cited in the function description of the corresponding functional modules of a device for coupling and calculating the heat load deviation coefficient of the water wall of a natural circulation boiler in the embodiment of the present invention, and will not be elaborated herein. The division of modules in the embodiment of the present invention is illustrative, only a logical function division. In actual implementation, there may be other division methods. In addition, in each embodiment of the present invention, the functional modules can be integrated in one processor, or exist separately physically, or two or more modules can be integrated in one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules.

[0077] In another embodiment of the present invention, a computer device is provided. The computer device includes a processor and a memory. The memory is used to store a computer program. The computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function. The processor described in the embodiment of the present invention can be used for the operation of a method for coupling and calculating the heat load deviation coefficient of the water wall of a natural circulation boiler.

[0078] In another embodiment of the present invention, the present invention further provides a storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device, used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, and the operating system of the terminal is stored in this storage space. Moreover, one or more instructions suitable for being loaded and executed by the processor are also stored in this storage space. These instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the method for coupling and calculating the thermal load deviation coefficient of the water-cooled wall of a natural circulation boiler in the above embodiment.

[0079] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0080] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one or more flows or multiple flows and / or blocks Figure 1 one or more blocks or multiple blocks.

[0081] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions in the Figure 1one process or multiple processes and / or blocks Figure 1 the functions specified in one block or multiple blocks.

[0082] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 the functions specified in one block or multiple blocks.

[0083] The present invention also provides a computer program product, since the computer program product is used to execute any one of the above-mentioned coupling calculation methods for the thermal load deviation coefficient of the water wall of a natural circulation boiler. Since the computer program product provided by the present invention and the above-mentioned coupling calculation method for the thermal load deviation coefficient of the water wall of a natural circulation boiler belong to the same inventive concept, the computer program product provided by the present invention has all the advantages of the above-mentioned coupling calculation method for the thermal load deviation coefficient of the water wall of a natural circulation boiler. Therefore, the beneficial effects of the computer program product provided by the present invention will not be described in detail herein one by one.

[0084] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0085] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit it. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present invention can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes, or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A coupled calculation method for the heat load deviation coefficient of the water-cooled wall of a natural circulation boiler, characterized in that Including: Obtaining the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the actual temperature of the measuring point position on the water wall surface; Performing water wall hydrodynamic calculation according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the preset heat load deviation coefficient of each loop, to obtain the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position; Taking the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position as the initial boundary conditions, performing temperature numerical simulation calculation on the measuring point position, comparing the temperature numerical simulation calculation result with the actual temperature at the measuring point position. If the absolute value of the difference between the two is not less than the preset deviation threshold, then after changing the heat load in the boundary conditions, re-performing temperature numerical simulation calculation on the measuring point position until the absolute value of the difference is less than the preset deviation threshold, outputting the heat load in the current boundary conditions, and this heat load is the actual furnace heat load at the measuring point position; Comparing the actual furnace heat load at the measuring point position with the theoretical heat load at the measuring point position to obtain the actual furnace heat load deviation value at the measuring point position; Fitting the actual furnace heat load deviation values of multiple measuring point positions at the same height to obtain the actual furnace heat load deviation distribution curve of the water wall of the natural circulation boiler.

2. The coupled calculation method for the heat load deviation coefficient of the water-cooled wall of a natural circulation boiler according to claim 1, characterized in that The measuring point positions are arranged at the back-fire side fin ends, fin roots, back-fire side vertices, and / or the fire side on the water wall finned tubes.

3. The coupling calculation method of the heat load deviation coefficient of the water wall of a natural circulation boiler according to claim 1, wherein, The performing water wall hydrodynamic calculation according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the preset heat load deviation coefficient of each loop is specifically as follows: Adopting the flow mesh system method to perform water wall hydrodynamic calculation according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the preset heat load deviation coefficient of each loop.

4. A coupling calculation method for the thermal load deviation coefficient of the water-cooled wall of a natural circulation boiler according to claim 1, characterized in that The taking the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position as the initial boundary conditions and performing temperature numerical simulation calculation on the measuring point position is specifically as follows: Adopting the Ansys Workbench two-dimensional steady-state thermal analysis model, and based on the temperature-dependent thermophysical properties of the water wall material of the natural circulation boiler, as well as the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position as the initial boundary conditions, performing mesh division and boundary condition setting. After the mesh division and boundary condition setting are completed, temperature numerical simulation calculation can be performed on the measuring point position.

5. A coupling calculation method for the heat load deviation coefficient of the water-cooled wall of a natural circulation boiler according to claim 4, characterized in that, The boundary condition setting is specifically as follows: where t w is the metal temperature of the water - cooled wall tube, in °C; t f is the working fluid temperature, in °C; λ is the thermal conductivity of the water - cooled wall material, in W / (m·°C); h is the convective heat transfer coefficient on the inner wall of the water - cooled wall tube, in W / (m 2 ·°C); q(x) is the heat flux density function on the outer wall of the water - cooled wall facing the fire, in W / m 2 ; is the second partial derivative of the water - cooled wall temperature t in the x - direction, and the x - direction is along the width direction of the water - cooled wall; is the second partial derivative of the water - cooled wall temperature t in the y - direction, and the y - direction is perpendicular to the wall surface of the water - cooled wall; is the temperature change rate of the outer wall of the water - cooled wall facing the fire, and n is the normal direction of the water - cooled wall surface; is the temperature change rate of the inner wall of the water - cooled wall tube; is the temperature change rate at other positions of the water - cooled wall; q0 is the heat load on the wall surface of the water - cooled wall, in W / m 2 ; is the angle factor function of the water - cooled wall facing the fire for the tube wall and fins.

6. The coupling calculation method for the heat load deviation coefficient of the water wall of a natural circulation boiler according to claim 1, wherein, The fitting the actual furnace heat load deviation values of multiple measuring point positions at the same height is specifically as follows: Fitting the actual furnace heat load deviation values of multiple measuring point positions at the same height based on the least squares method or polynomial regression algorithm.

7. A coupling calculation device for the heat load deviation coefficient of the water-cooled wall of a natural circulation boiler, characterized in that, Including: An acquisition module for obtaining the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the actual temperature of the measuring point position on the water wall surface; A hydrodynamic calculation module for performing water wall hydrodynamic calculation according to the flow rate, inlet and outlet pressures, inlet and outlet enthalpy values of the water wall, the measured outlet steam temperature of each loop, and the preset heat load deviation coefficient of each loop, to obtain the working medium temperature, initial heat load, and convective heat transfer coefficient at the measuring point position; An iterative module, which is used to take the working medium temperature, initial heat load and convective heat transfer coefficient at the measuring point position as initial boundary conditions, perform temperature numerical simulation calculations on the measuring point position, compare the results of the temperature numerical simulation calculations with the actual temperature at the measuring point position. If the absolute value of the difference between the two is not less than the preset deviation threshold, after changing the heat load in the boundary conditions, re-perform temperature numerical simulation calculations on the measuring point position until the absolute value of the difference is less than the preset deviation threshold, and output the heat load in the current boundary conditions, and this heat load is the actual furnace heat load at the measuring point position; A ratio module, which is used to compare the actual furnace heat load at the measuring point position with the theoretical heat load at the measuring point position to obtain the actual furnace heat load deviation value at the measuring point position; A fitting module, which is used to fit the actual furnace heat load deviation values at multiple measuring point positions at the same height to obtain the actual furnace heat load deviation distribution curve of the water wall of the natural circulation boiler; 8. A computer 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 computer program, it implements a method for coupling the heat load deviation coefficient of the water wall of a natural circulation boiler as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements a method for coupling the heat load deviation coefficient of the water wall of a natural circulation boiler as described in any one of claims 1 to 6.

10. A computer program product, characterized in that, When the computer program product is executed by the processor, it implements a method for coupling the heat load deviation coefficient of the water wall of a natural circulation boiler as described in any one of claims 1 to 6.

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