Water circulation design method for pipeline supporting boiler

Abstract

The invention belongs to the technical field of biomass boilers, and particularly relates to a water circulation design method for a pipeline support boiler, which comprises the following steps of: firstly, constructing a 3D geometric model of the biomass boiler, simplifying to obtain a simplified model, then defining material attributes and fluid attributes of the simplified model, performing stress simulation analysis by utilizing simulation software, and finally, calculating the water circulation of the pipeline support boiler. Obtaining a constraint lower limit of each pipeline size parameter in the simplified model meeting the structural mechanical property requirement, then forming an adjustment scheme by upwards adjusting each pipeline size parameter based on the constraint lower limit, and substituting the obtained adjustment scheme into the simplified model to obtain the structural mechanical property requirement. And after setting boundary conditions, carrying out finite element analysis by utilizing finite element analysis software to obtain a medium flow analysis result, and finally screening out an adjustment scheme with the most appropriate circulation ratio based on the medium flow analysis result. According to the biomass boiler, the circulation ratio of the biomass boiler can be effectively increased on the premise that the stress stability is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of biomass boiler technology, specifically relating to a water circulation design method for a pipe-supported boiler. Background Technology

[0002] With increasing concern about dependence on fossil fuels and environmental issues, biomass energy, as a renewable and clean energy source, has received widespread attention for its utilization technologies. Biomass boilers, as devices that use renewable biomass fuels (such as wood chips, straw, pellets, etc.) to generate heat or steam, are increasingly widely used in heating, industrial processing, and other fields. Their core components typically include a combustion furnace and an evaporator set on a steel frame.

[0003] In traditional biomass boiler design, the furnace, as the core high-temperature area for fuel combustion, and the evaporator, as a key pressure-bearing component of the water circulation system, require additional, independent steel frame or support systems to bear their weight, internal working fluid weight, and thermal stress, vibration, and wind / seismic loads generated during operation. Such support structures are usually welded or bolted from structural steel (such as I-beams and channel steel). The above-mentioned existing technologies still have the following defects: (1) The supporting steel frame occupies a certain amount of surrounding space, which limits the size of biomass boilers. (2) Biomass boilers operate at high temperatures, and the stress state is significantly different from that at room temperature. Traditional support structures do not fully consider high-temperature operating conditions, leading to systemic risks such as thermal stress concentration, structural instability, and accelerated material failure, resulting in poor safety. (3) The medium circulation ratio of biomass boilers is relatively low. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the existing technology by providing a water circulation design method for a pipe-supported boiler.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A water circulation design method for a pipe-supported boiler, the water circulation design method being based on the following pipe-supported boiler:

[0007] The pipeline-supported boiler includes a combustion grate, a rectangular tube frame, and an evaporator. The rectangular tube frame is fixed to the support structures on both sides of the grate. The rectangular tube frame is an internally connected liquid pipeline, including a lower header, an upper header, multiple first downcomers, multiple second downcomers, multiple risers, and multiple furnace heat exchange walls. The upper header includes two upper longitudinal headers, two first upper transverse headers, and three second upper transverse headers. The lower header includes two lower longitudinal headers and three lower transverse headers.

[0008] The two upper longitudinal collection boxes are arranged in parallel. The upper longitudinal collection box is connected to the middle of the evaporator through a riser pipe. The upper longitudinal collection box is also connected to the lower longitudinal collection box through a first downcomer pipe. The first upper horizontal collection box is arranged perpendicular to the upper longitudinal collection box. The first upper horizontal collection box is connected to the bottom of the evaporator through a second downcomer pipe. The first upper horizontal collection box is also connected to the end of the first downcomer pipe near the upper longitudinal collection box. The second upper horizontal collection box is arranged in parallel to the upper horizontal collection box and is located between the two first upper horizontal collection boxes. The two ends of the second upper horizontal collection box are respectively connected to the two upper longitudinal collection boxes.

[0009] The two lower longitudinal collection boxes are arranged in parallel, and the lower longitudinal collection boxes are provided with side membrane walls. The top and bottom ends of the side membrane walls are connected to the upper longitudinal collection box and the lower longitudinal collection box, respectively. The three lower transverse collection boxes are all arranged perpendicular to the lower longitudinal collection boxes. Two of the lower transverse collection boxes are located away from the boiler feed inlet and are connected to the lower longitudinal collection boxes. The remaining lower transverse collection box is located above the boiler feed inlet and is connected to the end of the first downcomer near the lower longitudinal collection box.

[0010] The top of the furnace heat exchange wall is connected to the second upper horizontal header, and the bottom of the furnace heat exchange wall is connected to the lower horizontal header.

[0011] The design method includes the following steps:

[0012] Step 1: Construct a 3D geometric model of the pipeline-supported boiler. Simplify the constructed 3D geometric model by retaining only the first downcomer, the side membrane wall, the upper longitudinal manifold connected to the retained side membrane wall, the lower longitudinal manifold, one end of the first upper transverse manifold connected to the retained upper longitudinal manifold, and one end of the riser connected to the retained upper longitudinal manifold, thus obtaining the simplified model.

[0013] Step 2: Define the material and fluid properties of the simplified model, and use simulation software to perform stress simulation analysis to obtain the lower limit of the pipe parameter constraints for the first downcomer and the side membrane wall in the simplified model that meets the structural mechanical performance requirements; the pipe parameters include pipe thickness and inner diameter, and number of pipes;

[0014] Step 3: Based on the lower limit of pipeline parameter constraints, adjust the pipeline parameters of the first downcomer and the side membrane wall in the simplified model upward to form an adjustment scheme. Substitute the obtained multiple adjustment schemes into the simplified model one by one, set the boundary conditions, and then use finite element analysis software to perform finite element analysis to obtain the medium flow analysis results of each adjustment scheme.

[0015] Step 4: Based on the results of the medium flow analysis, select the adjustment scheme with the optimal circulation ratio.

[0016] The results of the medium flow analysis include: fluid velocity in different first downcomers and fluid velocity in different side membrane walls;

[0017] Calculate the cycle ratio using the following formula:

[0018] ;

[0019] In the above formula, This is the cycle ratio; , These are the flow velocity and inner diameter of the i-th first downcomer, respectively; , The first Flow velocity and inner diameter of the membrane wall; , These refer to the number of the first downcomer and the number of the side membrane walls, respectively.

[0020] The boundary conditions include: the operating pressure of the pipe-supported boiler, the fluid temperature, and the heat load of the side membrane wall.

[0021] The boundary conditions include: setting the working pressure of the pipeline-supported boiler to 1.6 MPa; setting the fluid temperature to 204°C; and setting the heat load of the side membrane wall 411 to the highest fuel calorific value under maximum operating conditions.

[0022] The stress simulation analysis includes:

[0023] A combustion simulation solver is set up to simulate the combustion environment inside a pipe-supported boiler and conduct multiple combustion experiments. During the combustion experiments, relevant experimental data are collected, analyzed, and combustion and static stress analysis data are set in the simulation software based on the analysis results. The combustion simulation solver refers to the thermodynamic effect and free body force calculation model.

[0024] External loads are applied to the simplified model, and stress simulation analysis is performed using simulation software to obtain the mechanical performance simulation results of the simplified model. The mechanical performance simulation results include stress-strain contour maps and displacement contour maps. By examining the stress-strain contour maps and displacement contour maps, it is determined whether the mechanical performance simulation results of the simplified model meet the structural mechanical performance requirements. If not, the simplified model is further adjusted by adjusting the pipe size parameters in the simplified model until the simulation results meet the structural mechanical performance requirements.

[0025] The external loads include applying a uniformly distributed pressure surface load to the inner wall of the simplified model and applying the weight of the fluid to the pipes and internal structures.

[0026] In step 1, the constructed 3D geometric model is further meshed. The meshing process includes first dividing the 3D geometric model into tetrahedral meshes, then converting the tetrahedral meshes into hexahedral meshes, and then densifying the welding nodes within the 3D geometric model.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] In the water circulation design method of the pipe-supported boiler described in this invention, the pipe-supported boiler is an integrated structure composed of multiple interconnected pipes. A steam-water mixture with bubbles is generated in the lower heated furnace heat exchange wall and side membrane wall. Since the density of the steam-water mixture is less than that of water, it flows upwards to the evaporator along the riser pipe. Meanwhile, the denser water inside the evaporator and upper header flows downwards along the unheated first and second downcomers, thus forming a natural circulation system that absorbs the heat from boiler combustion. Simultaneously, the furnace and evaporator are supported by the pipes in this integrated structure, eliminating the need for additional support steel frames and allowing for larger boilers. The design method first simplifies the overall structure of the pipe-supported boiler, highlighting key areas affecting water circulation to obtain a simplified model. Then, stress simulation analysis is performed on the simplified model. Under the premise of meeting structural mechanical performance requirements, the lower limit of the pipe parameters in the simplified model is determined. Based on the lower limit of the pipe parameters, a structural adjustment scheme is designed. Finally, the optimal structural adjustment scheme for the circulation ratio is obtained through finite element analysis and applied to the overall structure of the pipe-supported boiler. Therefore, this invention effectively improves the circulation ratio of high-volume pipe-supported boilers while ensuring stress stability. Attached Figure Description

[0029] Figure 1 This is a perspective view of the pipeline-supported boiler described in this invention.

[0030] Figure 2 This is a front view of the pipe-supported boiler described in this invention, wherein the side membrane wall is omitted.

[0031] Figure 3 This is a side view of the pipe-supported boiler described in this invention.

[0032] Figure 4 This is a simplified model obtained by the design method described in this invention.

[0033] Figure 5 This is a schematic diagram illustrating the stress simulation analysis of a simplified model using the design method described in this invention.

[0034] Figure 6 This is a schematic diagram of the finite element analysis performed on a simplified model using the design method described in this invention.

[0035] In the diagram above, the components are: 1. Combustion grate; 2. Rectangular tube frame; 3. Evaporator; 4. Lower header; 41. Lower longitudinal header; 41. Side membrane wall; 42. Lower transverse header; 5. Upper header; 51. Upper longitudinal header; 52. First upper transverse header; 53. Second upper transverse header; 6. First downcomer; 7. Second downcomer; 8. Ascending pipe; and 9. Furnace heat exchange wall. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0037] See Figures 1 to 3 This invention provides a water circulation design method for a pipe-supported boiler, the water circulation design method being based on the following pipe-supported boiler:

[0038] The pipeline-supported boiler includes a combustion grate 1, a rectangular tube frame 2, and an evaporator 3. The rectangular tube frame 2 is fixed to the support structures on both sides of the grate 1. The rectangular tube frame 2 is an internally connected liquid pipeline, including a lower header 4, an upper header 5, multiple first downcomers 6, multiple second downcomers 7, multiple risers 8, and multiple furnace heat exchange walls 9. The upper header 5 includes two upper longitudinal headers 51, two first upper transverse headers 52, and three second upper transverse headers 53. The lower header 4 includes two lower longitudinal headers 41 and three lower transverse headers 42.

[0039] The two upper longitudinal collection boxes 51 are arranged in parallel. The upper longitudinal collection box 51 is connected to the middle of the evaporator 3 through the riser pipe 8. The upper longitudinal collection box 51 is also connected to the lower longitudinal collection box 41 through the first downcomer pipe 6. The first upper horizontal collection box 52 is arranged perpendicular to the upper longitudinal collection box 51. The first upper horizontal collection box 52 is connected to the bottom of the evaporator 3 through the second downcomer pipe 7. The first upper horizontal collection box 52 is also connected to the end of the first downcomer pipe 6 near the upper longitudinal collection box 51. The second upper horizontal collection box 53 is arranged in parallel to the upper horizontal collection box 52 and is located between the two first upper horizontal collection boxes 52. The two ends of the second upper horizontal collection box 53 are respectively connected to the two upper longitudinal collection boxes 51.

[0040] The two lower longitudinal collection boxes 41 are arranged in parallel. The lower longitudinal collection box 41 is provided with a side membrane wall 411. The top and bottom ends of the side membrane wall 411 are connected to the upper longitudinal collection box 51 and the lower longitudinal collection box 41, respectively. The three lower transverse collection boxes 42 are all arranged perpendicular to the lower longitudinal collection box 41. Two of the lower transverse collection boxes 42 are located away from the boiler feed inlet and are connected to the lower longitudinal collection box 41. The remaining lower transverse collection box 42 is located above the boiler feed inlet and is connected to the end of the first downcomer 6 near the lower longitudinal collection box 41.

[0041] The top end of the furnace heat exchange wall 9 is connected to the second upper horizontal header 53, and the bottom end of the furnace heat exchange wall 9 is connected to the lower horizontal header 42.

[0042] The aforementioned pipe-supported boiler is an integrated structure composed of multiple interconnected pipes. During operation, a steam-water mixture with bubbles is generated in the lower heated furnace heat exchange wall 9 and the side membrane wall 411. Since the density of the steam-water mixture is less than that of water, it flows upward to the evaporator along the riser pipe 8. Meanwhile, the denser water inside the evaporator 3 and the upper header 5 flows downward along the unheated first downcomer pipe 6 and the second downcomer pipe 7, thus forming a natural circulation system that absorbs the heat from the boiler combustion. At the same time, the furnace and evaporator 3 are supported by the various pipes in this integrated structure. With this structure, the boiler does not require an additional supporting steel frame, reducing the size and floor space of the boiler, and enabling the boiler to be made larger.

[0043] The water cycle design method is carried out in the following steps:

[0044] Step 1: Construct a 3D geometric model of the pipeline-supported boiler, and perform meshing and simplification processing on the constructed 3D geometric model;

[0045] Specifically, the meshing process refers to: first dividing the 3D geometric model into tetrahedral meshes, then converting the tetrahedral meshes into hexahedral meshes, and then refining the welding nodes within the 3D geometric model;

[0046] Specifically, the simplification process includes: retaining only the first downcomer 6, the side membrane wall 411, the upper longitudinal collector 51 connected to the retained side membrane wall 411, the lower longitudinal collector 41, one end of the first upper transverse collector 52 connected to the retained upper longitudinal collector 51, and one end of the riser 8 connected to the retained upper longitudinal collector 51, resulting in the following... Figure 4 The simplified model shown;

[0047] Step 2: Define the material and fluid properties of the simplified model, and use simulation software to perform stress simulation analysis to obtain the lower limit of pipe parameter constraints for the first downcomer 6 and the side membrane wall 411 in the simplified model that meets the structural mechanical performance requirements.

[0048] Specifically, the force simulation analysis includes:

[0049] A combustion simulation solver is set up to simulate the combustion environment inside a pipe-supported boiler and conduct multiple combustion experiments. During the combustion experiments, relevant experimental data are collected, analyzed, and combustion and static stress analysis data are set in the simulation software based on the analysis results. The combustion simulation solver refers to the thermodynamic effect and free body force calculation model.

[0050] External loads are applied to the simplified model, including a uniformly distributed pressure surface load on the inner wall of the simplified model and the weight of the fluid on the pipes and internal structure. Stress simulation analysis is performed using simulation software to obtain the mechanical performance simulation results of the simplified model, including stress-strain contour maps and displacement contour maps. By examining the stress-strain contour maps and displacement contour maps, it is determined whether the mechanical performance simulation results of the simplified model meet the structural mechanical performance requirements. If not, the simplified model is further adjusted by adjusting the parameters of each pipe in the simplified model until the simulation results meet the structural mechanical performance requirements.

[0051] Specifically, the pipeline parameters include the wall thickness and inner diameter of each pipeline, and the number of each pipeline; for example, the stress simulation analysis is as follows: Figure 5 As shown, Figure 5 Figure (a) shows a simplified model before the number of first downcomers 6 is adjusted, where there are two first downcomers 6. Figure (b) shows a simplified model after the number of first downcomers 6 is adjusted, where the number of first downcomers 6 is increased from two to three. The increase in the number of first downcomers 6 can not only increase the flow rate of the steam-water mixture in the side membrane wall 411, thereby increasing the circulation ratio, but also the newly added first downcomers 6 are supported between the middle of the lower longitudinal collection box 41 and the middle of the upper longitudinal collection box 51, which improves the overall structural rigidity, thereby ensuring the structural stability and safety of the boiler.

[0052] Step 3: Based on the lower limit of pipeline parameter constraints, an adjustment scheme is formed by adjusting the pipeline parameters of the first downcomer 6 and the side membrane wall 411 in the simplified model upwards. This can be done step-by-step according to the national standard specifications and models of steel pipes, such as GN / T17395-2024. Then, the obtained adjustment schemes are substituted one by one into the simplified model, boundary conditions are set, and finite element analysis is performed using finite element analysis software. The finite element analysis interface is shown below. Figure 6 As shown, the media flow analysis results for each adjustment scheme are obtained; the boundary conditions include: setting the working pressure of the pipeline-supported boiler to 1.6 MPa; setting the fluid temperature to 204℃; and setting the heat load of the side membrane wall 411 to the highest fuel calorific value under the maximum operating condition.

[0053] Step 4: Based on the media flow analysis results, select the optimal adjustment scheme for the circulation ratio. The optimal circulation ratio means that, under the premise that the circulation ratio is greater than 20, a smaller circulation ratio is better. The circulation ratio needs to be greater than 20 to ensure safety, and under this premise, a smaller circulation ratio can achieve better economic efficiency. The media flow analysis results include: fluid flow velocities of different first downcomers 6 and fluid flow velocities of different side membrane walls 411. The circulation ratio calculation formula is as follows:

[0054] ;

[0055] In the above formula, This is the cycle ratio; , These are the flow velocity and inner diameter of the i-th first downcomer 6, respectively; , The first The flow velocity and inner diameter of the side membrane wall 411; , These refer to the number of the first downcomer 6 and the side membrane wall 411, respectively. This represents the steam production of the simplified model; This represents the amount of water in the simplified model.

[0056] The above design method first simplifies the overall structure of the pipe-supported boiler, highlighting the key areas affected by water circulation to obtain a simplified model. Then, stress simulation analysis is performed on the simplified model. Based on the mechanical performance simulation results, the lower limit of the constraint on each pipe parameter in the simplified model is determined under the premise of meeting the structural mechanical performance requirements. Based on the lower limit of the constraint, an adjustment scheme is designed. Finally, the most suitable adjustment scheme for the circulation ratio is selected through finite element analysis and applied to the overall structure of the pipe-supported boiler. Through the above steps, the circulation ratio of the high-pipe-supported boiler can be significantly improved while ensuring stress stability.

[0057] Specific calculation example:

[0058] The lower limit of the constraints on the pipe dimensions in the simplified model is determined as follows: the inner diameter of the side membrane wall 411 is 60mm, the wall thickness is 4mm, and the quantity is 32; the first downcomer 6 is DN150 and the quantity is 2. Adjustment schemes 1-3 are obtained by progressively adjusting upwards. Adjustment scheme 1's parameter settings are: the inner diameter of the side membrane wall 411 is 60mm, the wall thickness is 4mm, and the quantity is 32; the first downcomer 6 is DN150 and the quantity is 2. Adjustment scheme 2's parameter settings are: the inner diameter of the side membrane wall 411 is 60mm, the wall thickness is 4mm, and the quantity is 32; the first downcomer 6 is DN150 and the quantity is 3. Adjustment scheme 3's parameter settings are: the inner diameter of the side membrane wall 411 is 60mm, the wall thickness is 4mm, and the quantity is 32; the first downcomer 6 is DN200 and the quantity is 2. The cycle ratios of adjustment schemes 1-3 obtained through finite element analysis are shown in Table 1.

[0059] Table 1. Cycle ratios for adjustment schemes 1-3

[0060]

[0061] As can be seen from the table above, the circulation ratio of adjustment scheme 3 is 22.39, which meets the premise that the circulation ratio is greater than 20 and is the minimum value among the three adjustment schemes. Therefore, adjustment scheme 3 is determined to be the optimal adjustment scheme, and adjustment scheme 3 will be applied to the overall structure of the pipeline-supported boiler.

Claims

1. A water circulation design method for a pipe-supported boiler, characterized in that: The water circulation design method is based on the following pipe-supported boiler: The pipeline-supported boiler includes a combustion grate (1), a rectangular tube frame (2), and an evaporator (3). The rectangular tube frame (2) is fixed on the support structure on both sides of the grate (1). The rectangular tube frame (2) is an internally connected liquid pipeline, including a lower header (4), an upper header (5), multiple first downcomers (6), multiple second downcomers (7), multiple risers (8), and multiple furnace heat exchange walls (9). The upper header (5) includes two upper longitudinal headers (51), two first upper transverse headers (52), and three second upper transverse headers (53). The lower header (4) includes two lower longitudinal headers (41) and three lower transverse headers (42). The two upper vertical collection boxes (51) are arranged in parallel. The upper vertical collection box (51) is connected to the middle of the evaporator (3) through the riser pipe (8). The upper vertical collection box (51) is also connected to the lower vertical collection box (41) through the first downcomer pipe (6). The first upper horizontal collection box (52) is arranged vertically to the upper vertical collection box (51). The first upper horizontal collection box (52) is connected to the bottom of the evaporator (3) through the second downcomer pipe (7). The first upper horizontal collection box (52) is also connected to the end of the first downcomer pipe (6) near the upper vertical collection box (51). The second upper horizontal collection box (53) is arranged in parallel to the upper horizontal collection box (52) and the second upper horizontal collection box (53) is located between the two first upper horizontal collection boxes (52). The two ends of the second upper horizontal collection box (53) are respectively connected to the two upper vertical collection boxes (51). The two lower longitudinal collection boxes (41) are arranged in parallel. The lower longitudinal collection box (41) is provided with a side membrane wall (411). The top and bottom of the side membrane wall (411) are connected to the upper longitudinal collection box (51) and the lower longitudinal collection box (41) respectively. The three lower transverse collection boxes (42) are all arranged perpendicular to the lower longitudinal collection box (41). Two of the lower transverse collection boxes (42) are located away from the boiler feed inlet and are connected to the lower longitudinal collection box (41). The remaining lower transverse collection box (42) is located above the boiler feed inlet and is connected to the end of the first downcomer (6) near the lower longitudinal collection box (41). The top of the furnace heat exchange wall (9) is connected to the second upper horizontal header (53), and the bottom of the furnace heat exchange wall (9) is connected to the lower horizontal header (42). The water circulation design method includes the following steps: Step 1: Construct a 3D geometric model of the pipeline-supported boiler. Simplify the constructed 3D geometric model by retaining only the first downcomer (6), the side membrane wall (411), the upper longitudinal manifold (51) connected to the retained side membrane wall (411), the lower longitudinal manifold (41), one end of the first upper transverse manifold (52) connected to the retained upper longitudinal manifold (51), and one end of the riser (8) connected to the retained upper longitudinal manifold (51) to obtain the simplified model. Step 2: Define the material and fluid properties of the simplified model, and use simulation software to perform stress simulation analysis to obtain the lower limit of pipe parameter constraints for the first downcomer (6) and the side membrane wall (411) in the simplified model that meets the structural mechanical performance requirements; the pipe parameters include pipe thickness and inner diameter, and number of pipes; Step 3: Based on the lower limit of the pipeline parameter constraint, the pipeline parameters of the first downcomer (6) and the side membrane wall (411) in the simplified model are adjusted upward to form an adjustment scheme. The multiple adjustment schemes are substituted into the simplified model one by one. After setting the boundary conditions, the finite element analysis software is used to perform finite element analysis to obtain the medium flow analysis results of each adjustment scheme. Step 4: Based on the results of the medium flow analysis, select the adjustment scheme with the optimal circulation ratio.

2. The water circulation design method for a pipe-supported boiler according to claim 1, characterized in that: The fluid flow analysis results include: fluid flow velocities of different first downcomers (6) and fluid flow velocities of different side membrane walls (411); Calculate the cycle ratio using the following formula: ； In the above formula, This is the cycle ratio; , The flow velocity and inner diameter of the i-th first downcomer (6) are respectively; , The first The flow velocity and inner diameter of the side membrane wall (411); , The numbers are respectively the number of the first downcomer (6) and the side membrane wall (411).

3. The water circulation design method for a pipe-supported boiler according to claim 1, characterized in that: The boundary conditions include: the working pressure of the pipeline-supported boiler, the fluid temperature, and the heat load of the side membrane wall (411).

4. The water circulation design method for a pipe-supported boiler according to claim 3, characterized in that: The boundary conditions include: setting the working pressure of the pipeline-supported boiler to 1.6 MPa; setting the fluid temperature to 204°C; and setting the heat load of the side membrane wall (411) to the highest fuel calorific value under the maximum operating conditions.

5. The water circulation design method for a pipe-supported boiler according to claim 1, characterized in that: The stress simulation analysis includes: A combustion simulation solver is set up to simulate the combustion environment inside a pipe-supported boiler and conduct multiple combustion experiments. During the combustion experiments, relevant experimental data are collected, analyzed, and combustion and static stress analysis data are set in the simulation software based on the analysis results. The combustion simulation solver refers to the thermodynamic effect and free body force calculation model. External loads are applied to the simplified model, and stress simulation analysis is performed using simulation software to obtain the mechanical performance simulation results of the simplified model. The mechanical performance simulation results include stress-strain contour maps and displacement contour maps. By examining the stress-strain contour maps and displacement contour maps, it is determined whether the mechanical performance simulation results of the simplified model meet the structural mechanical performance requirements. If not, the simplified model is further adjusted by adjusting the parameters of each pipe in the simplified model until the simulation results meet the structural mechanical performance requirements.

6. The water circulation design method for a pipe-supported boiler according to claim 5, characterized in that: The external loads include applying a uniformly distributed pressure surface load to the inner wall of the simplified model and applying the weight of the fluid to the pipes and internal structures.

7. The water circulation design method for a pipe-supported boiler according to claim 1, characterized in that: In step 1, the constructed 3D geometric model is further meshed. The meshing process includes first dividing the 3D geometric model into tetrahedral meshes, then converting the tetrahedral meshes into hexahedral meshes, and then densifying the welding nodes within the 3D geometric model.

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