A direct current wind tunnel device for gas diffusion simulation

Abstract

The application relates to the technical field of building pollutant detection, in particular to a direct-current wind tunnel device for gas diffusion simulation, which comprises a support frame, a direct-current wind tunnel integrated pipe fixed horizontally at the top end of the support frame and a negative pressure fan fixed at one end of the direct-current wind tunnel integrated pipe. Through the arrangement of a variable-diameter assembly and a telescopic assembly, the direct-current wind tunnel device can dynamically adjust the turbulence intensity when simulating the diffusion of gas pollutants, the turbulence generation structure does not need to be disassembled and replaced, the aperture size of the airflow channel can be directly changed through assembly linkage, the turbulence demand under different test scenes can be flexibly adapted, the problem of flow field damage in the pipeline caused by disassembly of the traditional fixed structure can be effectively avoided, the switching time of multi-turbulence scene test can be greatly shortened, the test efficiency can be significantly improved, and meanwhile, the supply amount of the humidifying medium can be synchronously adjusted through the arrangement of a flow regulation assembly, so that the airflow humidity under different turbulence states can be balanced.

Description

Technical Field

[0001] This invention relates to the field of building pollutant detection technology, specifically a DC wind tunnel device for simulating gas diffusion. Background Technology

[0002] A wind tunnel, or wind tunnel test chamber, is a tubular test device that artificially generates and controls airflow to simulate the flow of gas around an aircraft or physical object, test the effects of airflow on the object, and observe related physical phenomena. It is one of the most effective and commonly used tools for conducting aerodynamic tests, and wind tunnel devices are also commonly used in the process of simulating the diffusion of gaseous pollutants.

[0003] In existing DC wind tunnel systems, when simulating gaseous pollutant diffusion, the first step is to activate the negative pressure fan at the wind tunnel's tail end. The fan generates negative pressure to draw outside air into the inlet. The incoming air first passes through an inlet filtration system to remove dust and impurities, preventing interference with subsequent simulations. It then flows through the DC wind tunnel's integrated pipe, where an internal honeycomb rectifier and multi-layer damping mesh eliminate eddies and velocity fluctuations, creating a stable and uniform laminar flow. The rectified airflow then enters the environmental parameter adjustment stage. Temperature is first regulated by a temperature control mechanism, followed by humidity adjustment by a humidification mechanism to match actual atmospheric requirements. Next, it enters the turbulence generation section, where grids, perforated plates, or turbulence columns break up the laminar flow, generating turbulent characteristics that closely resemble those of the actual atmosphere. The airflow, carrying stable temperature, humidity, and turbulent characteristics, reaches the pollutant injection section. Simulated pollutants are introduced through a dedicated channel, forming a uniform mixture system before entering the test section containing a built-in scale model. As the pollutants flow through the model, they diffuse according to actual patterns. Measurement equipment in the test section captures and records the concentration distribution, diffusion range, and airflow parameters in real time. The airflow that completes the diffusion simulation flows through the tail filtration and purification section, where pollutants are removed by activated carbon adsorption, chemical neutralization, or filter membrane interception. After purification, the airflow is discharged. At the end of the test, the fan is turned off, the sewage injection is stopped, and the model and equipment are cleaned to complete the simulation process.

[0004] However, existing DC wind tunnel devices suffer from insufficient flexibility in turbulence adjustment when simulating gaseous pollutant diffusion. The turbulence intensity of airflow in the atmosphere fluctuates with weather and terrain changes, but the turbulence generators in existing DC wind tunnels are mostly fixed structures, such as grid-type or perforated plate-type turbulence generators. The turbulence intensity of these devices is fixed by their factory-set structural parameters and cannot be dynamically adjusted according to experimental requirements. To simulate pollutant diffusion under different turbulent conditions, the turbulence generator must be disassembled and replaced, which is cumbersome and time-consuming. During replacement, the airflow environment inside the duct is disrupted, and restoring the flow field takes a considerable amount of time, severely limiting the efficiency of comparative experiments with multiple turbulent scenarios. This makes it impossible to accurately reproduce complex atmospheric turbulence conditions and affects the accuracy of pollutant diffusion simulation results. Summary of the Invention

[0005] The purpose of this invention is to provide a DC wind tunnel device for simulating gas diffusion, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a DC wind tunnel device for simulating gas diffusion, comprising a support frame, a DC wind tunnel integrated pipe horizontally fixed to the top of the support frame, and a negative pressure fan fixed to one end of the DC wind tunnel integrated pipe. A transparent simulation box is fixedly connected to the end of the DC wind tunnel integrated pipe away from the negative pressure fan. An airflow discharge filter mechanism is fixedly installed through the end of the transparent simulation box away from the DC wind tunnel integrated pipe. A temperature control mechanism and a humidifying nozzle are installed inside the side of the DC wind tunnel integrated pipe closest to the negative pressure fan. A flow control component is installed on the outer side of the DC wind tunnel integrated pipe near the top of the humidification nozzle pipe. Two turbulence generating plates are symmetrically fixedly installed inside the DC wind tunnel integrated pipe near the humidification nozzle pipe. Several through holes are evenly spaced on the two turbulence generating plates. An installation cavity is opened between the two turbulence generating plates. A diameter reducing component is installed inside the installation cavity on the side near each through hole. A first arc-shaped block is fixedly installed on the inner wall of the top of the DC wind tunnel integrated pipe near the transparent simulation box. An adjustment component is installed on the outer side of the first arc-shaped block.

[0007] Furthermore, the variable diameter assembly includes a limiting ring shell and a positioning ring shell. The limiting ring shell is fixedly installed on one side of one of the turbulence generating plates facing the mounting cavity, and the positioning ring shell is fixedly installed on the other side of the turbulence generating plate facing the mounting cavity. The center lines of the limiting ring shell, the positioning ring shell, and the through hole coincide. A rotating ring is rotatably provided between the limiting ring shell and the positioning ring shell.

[0008] Furthermore, several arc-shaped baffles are evenly distributed around the rotating ring and the limiting ring shell, and several positioning posts are fixed around the inner wall of the limiting ring shell at equal intervals. Each arc-shaped baffle has a positioning hole through it at one end. The positioning hole is rotatably mounted on the outside of a positioning post on the corresponding side. Each arc-shaped baffle has an abutment post fixedly installed on the outside of the side closest to the positioning hole.

[0009] Furthermore, an arc-shaped groove is provided through the interior of the rotating ring near the contact post, one end of the contact post is inserted and slidably installed inside the arc-shaped groove, and a toothed ring is sleeved and fixed on the outside of the rotating ring, with a limiting toothed rack meshing on one side of the toothed ring.

[0010] Furthermore, a fixing frame is fixed to the top of the DC wind tunnel integrated tube, and a telescopic component is provided on the outside of the fixing frame; the telescopic component includes an electric telescopic rod and a contact frame, the electric telescopic rod is vertically fixed to the outside of the fixing frame, the contact frame is horizontally fixed to the outside of the output end of the electric telescopic rod, and several connecting rods are vertically fixed at equal intervals at the bottom of the contact frame, the several connecting rods correspond one-to-one with several limiting racks, and the top of each limiting rack is fixedly installed at the bottom of the corresponding connecting rod.

[0011] Furthermore, a mounting bracket is fixedly installed on the outside of the top of the DC wind tunnel integrated pipe near the fixed frame, and a liquid supply pump is fixedly installed on the top of the mounting bracket. The input end of the humidifying nozzle pipe is fixedly connected to the output end of the liquid supply pump. The flow control component includes a limit bracket and a control valve. The limit bracket is fixedly installed on the outside of one side of the contact frame, and the control valve is installed in series in the input pipe of the humidifying nozzle pipe to control the flow rate of the humidifying medium.

[0012] Furthermore, a limit gear is fixedly installed at the end of the valve stem of the control valve, and a drive rack is vertically fixed at one end of the limit frame near the limit gear, and the drive rack is meshed with the limit gear.

[0013] Furthermore, the DC wind tunnel integrated pipe is located on the side of the turbulence generating plate away from the negative pressure fan, and a simulated pollutant injection nozzle is fixedly installed inside it. A building model is placed inside the bottom of the transparent simulation box, and several detection probes are fixedly installed on the inner wall of the transparent simulation box around the building model.

[0014] Furthermore, the adjustment component includes an arc-shaped groove and a second arc-shaped block. The arc-shaped groove is formed inside the first arc-shaped block, and the second arc-shaped block is slidably installed inside the arc-shaped groove. A positioning seat is fixedly installed on the outside of the DC wind tunnel integrated tube near the top of the first arc-shaped block. A stepper motor is fixedly installed on one side of the positioning seat. A take-up reel is fixedly installed at the output end of the stepper motor. A pull rope is wound around the outside of the take-up reel. One end of the pull rope passes through the side wall of the DC wind tunnel integrated tube and is fixedly connected to one end of the second arc-shaped block.

[0015] Furthermore, a positioning block is fixedly installed inside the arc-shaped groove near the top, a spring is fixedly installed at one end of the positioning block, and the end of the spring away from the positioning block is embedded and fixedly installed inside the second arc-shaped block.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] By incorporating variable-diameter and telescopic components, this DC wind tunnel device can dynamically adjust turbulence intensity during gaseous pollutant diffusion simulations. This eliminates the need to disassemble or replace the turbulence-generating structure; the orifice size of the airflow channel is directly altered via component linkage, flexibly adapting to the turbulence requirements of different test scenarios. This effectively avoids the flow field disruption issues within the pipes caused by disassembly of traditional fixed structures, significantly shortening the switching time between multiple turbulence scenarios and substantially improving test efficiency. Simultaneously, the flow control component allows for synchronized adjustment of the humidification medium supply, balancing airflow humidity under different turbulence conditions. In high-turbulence scenarios, humidification compensates for airflow evaporation losses, preventing concentration distortion of water-soluble pollutants due to dry environments. In low-turbulence scenarios, reduced humidification prevents condensation, ensuring that the pollutant diffusion process is unaffected by humidity fluctuations and further improving the accuracy of simulation data.

[0018] By adjusting the component settings, this DC wind tunnel device can adapt to the airflow coverage requirements of different scale models when simulating the diffusion of gaseous pollutants. There is no need to manually adjust the airflow channel shape of the test section. The components can dynamically change the cross-sectional height and range of airflow, avoiding the problems of airflow being suspended in low models (airflow flows over the top of the model without fully utilizing it) and airflow being cut off in tall models (airflow cannot cover the top of the model). At the same time, it can guide the airflow to fully conform to the periphery of the model, accurately reproduce the obstruction and bypass effects of obstacles of different heights on the diffusion of pollutants, reduce simulation deviations caused by improper airflow coverage, make the test results closer to the diffusion law of pollutants in the actual atmospheric environment, and improve the realism of pollution simulation in scenarios such as building periphery and complex terrain. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the overall cross-sectional three-dimensional structure of the present invention;

[0021] Figure 3 This is a partial cross-sectional three-dimensional structural schematic diagram of the DC wind tunnel integrated pipe and turbulence generating plate of the present invention;

[0022] Figure 4 For the present invention Figure 3 Enlarged structural diagram at point A in the middle;

[0023] Figure 5 This is a partial cross-sectional three-dimensional structural schematic diagram of the turbulence generating plate and the limiting ring shell of the present invention;

[0024] Figure 6 This is a three-dimensional structural diagram showing the separation of the limiting ring shell and the positioning ring shell of the present invention;

[0025] Figure 7This is a three-dimensional structural diagram of the mounting bracket and liquid supply pump of the present invention;

[0026] Figure 8 For the present invention Figure 7 Enlarged structural diagram at point B;

[0027] Figure 9 This is a partial cross-sectional three-dimensional structural schematic diagram of the first arc-shaped block and the second arc-shaped block of the present invention;

[0028] Figure 10 For the present invention Figure 9 Enlarged structural diagram at point C;

[0029] Figure 11 For the present invention Figure 9 Enlarged structural diagram at point D;

[0030] Figure 12 This is a schematic diagram demonstrating turbulence passing through the second arc-shaped block.

[0031] The attached diagram lists the components represented by each number as follows:

[0032] 1. Support frame; 2. DC wind tunnel integrated pipe; 3. Negative pressure fan; 4. Transparent simulation box; 5. Airflow exhaust filtration mechanism; 6. Temperature control mechanism; 7. Humidifying nozzle pipe; 8. Mounting bracket; 9. Liquid supply pump; 10. Turbulence generating plate; 11. Through hole; 12. Mounting cavity; 13. Limiting ring shell; 14. Positioning ring shell; 15. Arc-shaped baffle; 16. Positioning hole; 17. Positioning post; 18. Rotating ring; 19. Arc-shaped groove; 20. Contact post; 21. Fixing bracket; 22. 23. Electric telescopic pole; 24. Contact frame; 25. Connecting rod; 26. Limiting rack; 27. Gear ring; 28. Pull rope; 29. ​​First arc-shaped block; 30. Arc-shaped slide groove; 31. Second arc-shaped block; 32. Positioning seat; 33. Reel; 34. Stepper motor; 35. Positioning block; 36. Spring; 37. Architectural model; 38. Detection probe; 39. Simulated pollutant injection nozzle; 40. Limiting frame; 41. Control valve; 42. Limiting gear; 43. Drive rack. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1: Please refer to Figure 1 - Figure 8A DC wind tunnel device for simulating gas diffusion includes a support frame 1, a DC wind tunnel integrated pipe 2 horizontally fixed to the top of the support frame 1, and a negative pressure fan 3 fixed to one end of the DC wind tunnel integrated pipe 2. A transparent simulation box 4 is fixedly connected and communicated to the end of the DC wind tunnel integrated pipe 2 away from the negative pressure fan 3. An airflow discharge filter mechanism 5 is fixedly installed through the end of the transparent simulation box 4 away from the DC wind tunnel integrated pipe 2. A temperature control mechanism 6 and a humidifying nozzle pipe 7 are installed inside the side of the DC wind tunnel integrated pipe 2 near the negative pressure fan 3. A flow control component is provided on the outside of the top of the DC wind tunnel integrated pipe 2 near the humidifying nozzle pipe 7. Two turbulence generating plates 10 are symmetrically fixedly installed inside the DC wind tunnel integrated pipe 2 near the humidifying nozzle pipe 7. Several through holes 11 are equally spaced through the two turbulence generating plates 10. An installation cavity 12 is provided between the two turbulence generating plates 10. A diameter reducing component is provided inside the side of the installation cavity 12 near each through hole 11.

[0035] The variable diameter assembly includes a limiting ring shell 13 and a positioning ring shell 14. The limiting ring shell 13 is fixedly installed on the side of one of the turbulence generating plates 10 facing the mounting cavity 12, and the positioning ring shell 14 is fixedly installed on the side of the other turbulence generating plate 10 facing the mounting cavity 12. The center lines of the limiting ring shell 13, the positioning ring shell 14 and the through hole 11 coincide. A rotating ring 18 is rotatably disposed between the limiting ring shell 13 and the positioning ring shell 14.

[0036] A number of arc-shaped baffles 15 are evenly distributed around the rotating ring 18 and the limiting ring shell 13. A number of positioning posts 17 are fixed around the inner wall of the limiting ring shell 13 at equal intervals. A positioning hole 16 is opened through one end of each arc-shaped baffle 15. The positioning hole 16 is rotatably mounted on the outside of a positioning post 17 on the corresponding side. An abutment post 20 is fixedly installed on the outside of the side of each arc-shaped baffle 15 near the positioning hole 16.

[0037] An arc-shaped groove 19 is provided through the interior of the rotating ring 18 near the contact post 20. One end of the contact post 20 is inserted and slidably installed inside the arc-shaped groove 19. A toothed ring 26 is fixedly sleeved on the outside of the rotating ring 18. One side of the toothed ring 26 is engaged with a limiting toothed rack 25.

[0038] The top of the DC wind tunnel integrated tube 2 is fixed with a fixing frame 21, and a telescopic component is provided on the outside of the fixing frame 21. The telescopic component includes an electric telescopic rod 22 and a contact frame 23. The electric telescopic rod 22 is vertically fixed on the outside of the fixing frame 21, and the contact frame 23 is horizontally fixed on the outside of the output end of the electric telescopic rod 22. Several connecting rods 24 are vertically fixed at equal intervals at the bottom of the contact frame 23. Several connecting rods 24 correspond one-to-one with several limiting racks 25. The top of each limiting rack 25 is fixedly installed on the bottom of the corresponding connecting rod 24.

[0039] A mounting bracket 8 is fixedly installed on the top of the DC wind tunnel integrated pipe 2 near the top of the fixed frame 21. A liquid supply pump 9 is fixedly installed on the top of the mounting bracket 8. The input end of the humidifying nozzle pipe 7 is fixedly connected to the output end of the liquid supply pump 9. The flow control component includes a limit frame 39 and a control valve 40. The limit frame 39 is fixedly installed on the outside of one side of the contact frame 23. The control valve 40 is installed in series in the input end pipeline of the humidifying nozzle pipe 7 to control the flow rate of the humidifying medium.

[0040] A limit gear 41 is fixedly installed at the end of the valve stem of the control valve 40. A drive rack 42 is vertically fixed at one end of the limit frame 39 near the limit gear 41. The drive rack 42 is meshed with the limit gear 41.

[0041] The DC wind tunnel integrated pipe 2 is located on the side of the turbulence generating plate 10 away from the negative pressure fan 3. A simulated pollutant injection nozzle 38 is fixed inside the pipe. A building model 36 is placed inside the bottom of the transparent simulation box 4. Several detection probes 37 are fixedly installed on the inner wall of the transparent simulation box 4 around the building model 36.

[0042] In this embodiment, during operation, a building model 36 of the scene to be simulated is first placed inside the bottom of the transparent simulation box 4. This ensures that the several detection probes 37 installed around the inner wall of the building model 36 are in normal working order, preparing for subsequent collection of pollutant diffusion data. Then, the negative pressure fan 3, fixed to one end of the DC wind tunnel integration pipe 2, is started. The negative pressure fan 3 generates continuous negative pressure suction, drawing outside air into the DC wind tunnel integration pipe 2, thus initiating the entire simulation process.

[0043] After the outside air enters the DC wind tunnel integrated pipe 2, it first flows through the temperature control mechanism 6 installed inside the side near the negative pressure fan 3. The temperature control mechanism 6 adjusts the airflow temperature through heating or cooling to make the airflow reach the ambient temperature conditions set for the test, thus laying a stable temperature foundation for subsequent simulation of pollutant diffusion at different temperatures. The temperature-adjusted airflow continues forward, flowing towards the area where the humidifying nozzle pipe 7 is located. At this time, the liquid supply pump 9 installed at the top of the mounting bracket 8 is activated, and the liquid supply pump 9 delivers the humidifying medium to the humidifying nozzle pipe 7. Simultaneously, the flow control component operates synchronously: if the turbulence intensity needs to be adjusted later, the electric telescopic rod 22 fixed outside the mounting bracket 21 will drive the contact bracket 23 at its output end to move up and down. The limiting bracket 39 fixed on one side of the contact bracket 23 moves accordingly. The drive rack 42 at the end of the limiting bracket 39 near the limiting gear 41 meshes with the limiting gear 41, driving the valve stem of the control valve 40 to rotate, thereby adjusting the opening of the control valve 40. When the turbulence intensity needs to be increased, the opening of the control valve 40 is increased to increase the humidification amount, compensate for the evaporation loss of the airflow in strong turbulence, and avoid concentration distortion of water-soluble pollutants due to the dry environment. When the turbulence intensity needs to be decreased, the opening of the control valve 40 is decreased to reduce the humidification amount, prevent the airflow in weak turbulence from condensing and accumulating water, ensure that the airflow humidity always matches the test requirements, and maintain a stable pollutant diffusion environment.

[0044] After the airflow has completed temperature and humidity regulation, it continues to flow to the two turbulence generating plates 10 that are symmetrically fixed inside the DC wind tunnel integrated pipe 2. At this time, the turbulence intensity is dynamically adjusted through the linkage of the telescopic component and the variable diameter component: when the electric telescopic rod 22 drives the contact frame 23 to move, several connecting rods 24 fixed at the bottom of the contact frame 23 move synchronously, and the limiting rack 25 fixed at the bottom of each connecting rod 24 moves up and down accordingly. The limiting rack 25 meshes with the toothed ring 26 fixed on the outside of the rotating ring 18, causing the rotating ring 18 to fit and rotate between the limiting ring shell 13 and the positioning ring shell 14. When the rotating ring 18 rotates, the arc-shaped groove 19 running through it drives the sliding of the contact post 20 on the outside of the arc-shaped baffle 15. The arc-shaped baffle 15 rotates around the positioning post 17 fixed to the inner wall of the limiting ring shell 13 through the positioning hole 16 at one end, realizing the opening and closing of the arc-shaped baffle 15 between the rotating ring 18 and the limiting ring shell 13. When the arc-shaped baffle 15 opens, the actual diameter of the through hole 11 increases, the airflow resistance decreases, and weak turbulence is formed; when the arc-shaped baffle 15 closes, the actual diameter of the through hole 11 decreases, the disturbance of the airflow increases, and strong turbulence is formed. This process can dynamically adjust the turbulence intensity without disassembling any parts, effectively avoiding the problem of the internal flow field destruction caused by disassembly of traditional fixed turbulence structures, greatly shortening the switching time of multi-turbulence scenario experiments, and significantly improving the experimental efficiency.

[0045] When the airflow, carrying stable temperature and humidity and well-regulated turbulence characteristics, flows through the simulated pollutant injection nozzle 38 inside the DC wind tunnel integrated pipe 2, the simulated pollutant injection nozzle 38 is connected to the external pollutant source, precisely injecting the simulated pollutants required for the experiment into the airflow. The airflow, relying on its own turbulence characteristics, fully mixes with the pollutants, forming a uniform mixture system. Subsequently, the mixed airflow enters the transparent simulation chamber 4, which is fixedly connected to and communicates with the DC wind tunnel integrated pipe 2. As it flows around the building model 36, the pollutants diffuse according to a pattern similar to that in the actual atmosphere due to the obstruction and flow around the building model 36, forming a diffusion trajectory close to the real environment. During this process, the detection probe 37 on the inner wall of the transparent simulation chamber 4 captures the concentration distribution, diffusion range, and changes in airflow speed and direction in real time, accurately recording the experimental data and providing a reliable basis for subsequent analysis of the diffusion patterns of pollutants around the building.

[0046] The airflow that has completed the diffusion simulation carries pollutants that have not been completely diffused and eventually flows to the transparent simulation box 4. The end of the integrated pipe 2 of the DC wind tunnel passes through a fixed airflow discharge filter mechanism 5. The airflow discharge filter mechanism 5 removes pollutants from the airflow through activated carbon adsorption, chemical neutralization or filter membrane interception to avoid direct emission and environmental impact. The purified airflow is then discharged through the airflow discharge filter mechanism 5. At this point, the entire gaseous pollutant diffusion simulation process is completed.

[0047] Example 2: Please refer to Figure 9 - Figure 12 This embodiment further illustrates Example 1. A first arc-shaped block 28 is fixedly installed on the inner wall of the top of the DC wind tunnel integrated tube 2 near the transparent simulation box 4. An adjustment component is provided on the outside of the first arc-shaped block 28.

[0048] The adjustment assembly includes an arc-shaped slide 29 and a second arc-shaped block 30. The arc-shaped slide 29 is opened inside the first arc-shaped block 28, and the second arc-shaped block 30 is slidably installed inside the arc-shaped slide 29. A positioning seat 31 is fixedly installed on the outside of the DC wind tunnel integrated tube 2 near the top of the first arc-shaped block 28. A stepper motor 33 is fixedly installed on one side of the positioning seat 31. A take-up reel 32 is fixedly installed at the output end of the stepper motor 33. A pull rope 27 is wound around the outside of the take-up reel 32. One end of the pull rope 27 passes through the side wall of the DC wind tunnel integrated tube 2 and is fixedly connected to one end of the second arc-shaped block 30.

[0049] A positioning block 34 is fixedly installed inside the arc-shaped slide 29 near the top. A spring 35 is fixedly installed at one end of the positioning block 34. The end of the spring 35 away from the positioning block 34 is embedded and fixedly installed inside the second arc-shaped block 30.

[0050] In this embodiment, based on the airflow temperature and humidity adjustment, turbulence intensity dynamic control and pollutant injection process of Embodiment 1, a building model 36 of the corresponding height is first placed at the bottom of the transparent simulation box 4 according to the scenario to be simulated. If it is a low building model 36 (such as a scaled model of a low-rise building complex in a residential area), it is necessary to prevent the airflow from passing over the top of the model. If it is a tall building model 36 (such as a scaled model of a high-rise building), it is necessary to prevent the airflow from acting only on the middle of the model, causing the top diffusion to be cut off. At this time, the adjustment component of the DC wind tunnel integration pipe 2 near the transparent simulation box 4 is activated.

[0051] When the adjustment component is working, the stepper motor 33 fixed on one side of the positioning seat 31 is started first. When the low-rise building model 36 is placed, the stepper motor 33 rotates in reverse, driving the winding reel 32 fixed at its output end to release the pull rope 27. At this time, the spring 35 fixed at one end of the positioning block 34 inside the arc-shaped slide 29 loses the tension restraint of the pull rope 27, elastically resets, and pushes the second arc-shaped block 30 to slide down along the arc-shaped slide 29 inside the first arc-shaped block 28. During the downward movement of the second arc-shaped block 30, the cross-sectional height of the airflow channel from the DC wind tunnel integration pipe 2 to the transparent simulation box 4 is gradually reduced, so that after the airflow enters the transparent simulation box 4, it can flow closely to the surface of the low-rise building model 36, avoiding the airflow from being suspended above the model due to the channel being too high, and ensuring that the diffusion trajectory of pollutants blocked by the model and flowing around it conforms to the actual laws of the surrounding area of ​​low-rise buildings.

[0052] When the tall building model 36 is placed, the stepper motor 33 rotates in the forward direction, and the reel 32 tightens the pull rope 27. One end of the pull rope 27 passes through the side wall of the DC wind tunnel integrated pipe 2 and pulls the second arc-shaped block 30 to slide upward along the arc-shaped slide groove 29. The spring 35 is stretched and stores energy synchronously. As the second arc-shaped block 30 slides upward, the cross-sectional height of the airflow channel gradually increases, allowing the airflow to carry pollutants into the transparent simulation box 4 and completely cover the top area of ​​the tall building model 36. This avoids the airflow not being able to reach the top of the model due to the channel being too low, accurately reproducing the lifting and diffusion effect of the vortex at the top of the high-rise building on the pollutants, and eliminating the problem of missing top diffusion data caused by the fixed airflow height in traditional wind tunnels.

[0053] Regardless of the up-and-down sliding of the second arc-shaped block 30, its arc-shaped structure always remains tightly fitted with the arc-shaped groove 29 of the first arc-shaped block 28, ensuring smooth airflow along the arc-shaped surface without local eddies or airflow leakage, maintaining the stable turbulence and temperature / humidity environment established in Example 1. Subsequently, the airflow carrying pollutants flows through the building model 36 at an appropriate height. The detection probes 37 installed around the model on the inner wall of the transparent simulation box 4 can accurately capture the pollutant concentration distribution, diffusion range, and airflow parameters around the model at different heights. The recorded data can more comprehensively reflect the impact of buildings of different heights on pollution diffusion in the actual atmosphere. Finally, the airflow that has completed the diffusion simulation is still purified and discharged through the airflow discharge filter mechanism 5 at the end of the transparent simulation box 4. The entire process does not require manual disassembly or adjustment of the airflow channel components. The model height can be dynamically adapted simply by the linkage between the stepper motor 33 and the pull rope 27, greatly improving the flexibility and realism of pollution simulation in complex building scenarios and making up for the shortcomings of fixed airflow height in traditional wind tunnels.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A DC wind tunnel device for simulating gas diffusion, comprising a support frame (1), a DC wind tunnel integrated pipe (2) horizontally fixed to the top of the support frame (1), and a negative pressure fan (3) fixed to one end of the DC wind tunnel integrated pipe (2), characterized in that: The end of the DC wind tunnel integrated pipe (2) away from the negative pressure fan (3) is fixedly connected to and communicates with a transparent simulation box (4). The end of the transparent simulation box (4) away from the DC wind tunnel integrated pipe (2) is fixedly connected to an airflow discharge filter mechanism (5). A temperature control mechanism (6) and a humidifying nozzle pipe (7) are installed inside the side of the DC wind tunnel integrated pipe (2) near the negative pressure fan (3). A flow control component is provided on the outside of the top of the DC wind tunnel integrated pipe (2) near the humidifying nozzle pipe (7). Two turbulence generating plates (10) are symmetrically fixedly installed inside the head tube (7). Several through holes (11) are equally spaced on the two turbulence generating plates (10). An installation cavity (12) is opened between the two turbulence generating plates (10). A variable diameter component is provided inside the side of the installation cavity (12) near each through hole (11). A first arc-shaped block (28) is fixedly installed on the inner wall of the top of the DC wind tunnel integrated pipe (2) near the transparent simulation box (4). An adjustment component is provided on the outside of the first arc-shaped block (28).

2. The DC wind tunnel device for simulating gas diffusion according to claim 1, characterized in that: The variable diameter assembly includes a limiting ring shell (13) and a positioning ring shell (14). The limiting ring shell (13) is fixedly installed on one side of a turbulence generating plate (10) facing the mounting cavity (12), and the positioning ring shell (14) is fixedly installed on the other side of a turbulence generating plate (10) facing the mounting cavity (12). The center lines of the limiting ring shell (13), the positioning ring shell (14) and the through hole (11) coincide. A rotating ring (18) is rotatably disposed between the limiting ring shell (13) and the positioning ring shell (14).

3. The DC wind tunnel device for simulating gas diffusion according to claim 2, characterized in that: A plurality of arc-shaped baffles (15) are evenly distributed around the rotating ring (18) and the limiting ring shell (13). A plurality of positioning posts (17) are fixed around the inner wall of the limiting ring shell (13) at equal intervals. A positioning hole (16) is opened through one end of each arc-shaped baffle (15). The positioning hole (16) is rotatably mounted on the outside of a positioning post (17) on the corresponding side. A contact post (20) is fixedly installed on the outside of the side of each arc-shaped baffle (15) near the positioning hole (16).

4. The DC wind tunnel device for simulating gas diffusion according to claim 3, characterized in that: The rotating ring (18) has an arc-shaped groove (19) that runs through the interior of the contact post (20). One end of the contact post (20) is inserted and slidably installed inside the arc-shaped groove (19). A toothed ring (26) is sleeved and fixed on the outside of the rotating ring (18). One side of the toothed ring (26) is engaged with a limiting toothed rack (25).

5. A DC wind tunnel device for simulating gas diffusion according to claim 4, characterized in that: The top of the DC wind tunnel integrated pipe (2) is fixed with a fixing frame (21), and the fixing frame (21) is provided with a telescopic component. The telescopic assembly includes an electric telescopic rod (22) and a contact frame (23). The electric telescopic rod (22) is vertically fixed to the outside of the fixed frame (21). The contact frame (23) is horizontally fixed to the outside of the output end of the electric telescopic rod (22). Several connecting rods (24) are vertically fixed at equal intervals at the bottom end of the contact frame (23). Several connecting rods (24) correspond one-to-one with several limiting racks (25). The top end of each limiting rack (25) is fixedly installed at the bottom end of the corresponding connecting rod (24).

6. A DC wind tunnel device for simulating gas diffusion according to claim 5, characterized in that: The DC wind tunnel integrated pipe (2) is fixedly mounted with a mounting bracket (8) near the top of the fixed frame (21). The top of the mounting bracket (8) is fixedly mounted with a liquid supply pump (9). The input end of the humidifying nozzle pipe (7) is fixedly connected to the output end of the liquid supply pump (9). The flow control component includes a limit frame (39) and a control valve (40). The limit frame (39) is fixedly mounted on the outside of one side of the contact frame (23). The control valve (40) is connected in series in the input end pipeline of the humidifying nozzle pipe (7) to control the flow rate of the humidifying medium.

7. A DC wind tunnel device for simulating gas diffusion according to claim 6, characterized in that: The valve stem end of the control valve (40) is fixedly installed with a limiting gear (41), and the end of the limiting frame (39) near the limiting gear (41) is vertically fixed with a drive rack (42), which meshes with the limiting gear (41).

8. A DC wind tunnel device for simulating gas diffusion according to claim 1, characterized in that: The DC wind tunnel integrated pipe (2) is located on the side of the turbulence generating plate (10) away from the negative pressure fan (3) and a simulated pollutant injection nozzle (38) is fixed inside. The bottom of the transparent simulation box (4) contains a building model (36) and several detection probes (37) are fixedly installed on the inner wall of the transparent simulation box (4) around the building model (36).

9. A DC wind tunnel device for simulating gas diffusion according to claim 1, characterized in that: The adjustment assembly includes an arc-shaped slide (29) and a second arc-shaped block (30). The arc-shaped slide (29) is opened inside the first arc-shaped block (28). The second arc-shaped block (30) is slidably installed inside the arc-shaped slide (29). A positioning seat (31) is fixedly installed on the outside of the DC wind tunnel integrated tube (2) near the top of the first arc-shaped block (28). A stepper motor (33) is fixedly installed on one side of the positioning seat (31). A take-up reel (32) is fixedly installed at the output end of the stepper motor (33). A pull rope (27) is wound around the outside of the take-up reel (32). One end of the pull rope (27) passes through the side wall of the DC wind tunnel integrated tube (2) and is fixedly connected to one end of the second arc-shaped block (30).

10. A DC wind tunnel device for simulating gas diffusion according to claim 9, characterized in that: A positioning block (34) is fixedly installed inside the arc-shaped groove (29) near the top. A spring (35) is fixedly installed at one end of the positioning block (34). The end of the spring (35) away from the positioning block (34) is embedded and fixedly installed inside the second arc-shaped block (30).

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