A grid type air bag type air volume regulating door and a rotary air preheater comprising the same

Abstract

The application discloses a grid type air bag type air volume regulating door and a rotary air preheater comprising the same. The grid type air bag type air volume regulating door comprises a grid type air source distribution support, strip-shaped air bags and a door frame. The grid type air source distribution support comprises a distribution main pipe, branch pipes and strip-shaped supports. The number of the branch pipes and the strip-shaped supports is more than two and one-to-one correspondence. Each strip-shaped support is arranged on the inner side of the door frame to form a grid structure. One end of the branch pipe is communicated with the distribution main pipe and the other end is connected with the corresponding strip-shaped support. Each strip-shaped support is provided with a strip-shaped air bag. The inner side of the branch pipe and the strip-shaped air bag is communicated. When the strip-shaped air bag is in a completely deflated state, a space is left between the adjacent strip-shaped air bags and the adjacent strip-shaped supports. When the strip-shaped air bags are filled with gas, the inner side of the door frame is blocked. The application can be used for the temperature rise of the split ring of the rotary heat exchanger. The application has good adaptability, is easy to adjust and control, improves uniformity, saves space and reduces cost.

Description

Technical Field

[0001] This invention relates to a grille-type airbag-type air volume regulating gate and a rotary air preheater containing it, belonging to the field of industrial valve technology. Background Technology

[0002] A valve is a device used in a fluid system to control the direction, pressure, and flow rate of a fluid. It is a device that allows the medium (liquid, gas, powder) in piping and equipment to flow or stop and controls its flow rate.

[0003] Valves are control components in pipeline fluid transport systems, used to change the cross-sectional area of ​​the passage and the direction of medium flow. They have functions such as guiding, stopping, throttling, checking back, diverting, or overflowing and relieving pressure. Valves used for fluid control range from the simplest shut-off valves to various valves used in extremely complex automatic control systems. Their types and specifications are numerous, with nominal diameters ranging from extremely small instrument valves to industrial pipeline valves with diameters up to 10 meters. They can be used to control the flow of various types of fluids, including water, steam, oil, gas, slurry, various corrosive media, liquid metals, and radioactive fluids.

[0004] Valves can be controlled by various transmission methods, such as manual, electric, hydraulic, pneumatic, turbine, electromagnetic, electromagnetic-hydraulic, electro-hydraulic, pneumatic-hydraulic, spur gear, bevel gear drive, etc. They can operate according to predetermined requirements under the action of pressure, temperature or other forms of sensor signals, or simply open or close without relying on sensor signals. Valves rely on drive or automatic mechanisms to make the opening and closing parts move up and down, slide, swing or rotate, thereby changing the size of their flow channel area to achieve their control function.

[0005] Airflow regulating valves are a sub-branch of the valve industry, with the most common type being the baffle valve. Baffle valves are commonly used in power plants or other industries for cutting off the flow of media in flue pipes and ducts. The valve core has a single or multiple flap structure, with an opening and closing angle of 90 degrees. Baffle valves have both fully open and fully closed functions, allowing the media in a certain pipeline to flow completely or be completely shut off. They also have a certain regulating function, changing the flow rate of the media in a certain pipeline.

[0006] The aforementioned baffle gates can generally only be designed as regular rectangles or circles, and are not suitable for irregular shapes; since opening and closing requires rotating the gate core 90 degrees, sufficient space is required both upstream and downstream of the installation section; after the airflow passes through the flap with a certain angle, the airflow direction is deflected, which is not conducive to reducing flow resistance and also increases the difficulty of flow measurement; baffle gates generally cannot be completely and tightly closed, and their adjustment characteristics are not very good; the installation position of the external power transmission mechanism of the baffle gate is not flexible.

[0007] For the reasons mentioned above, the application of baffle gates in actual industrial scenarios is limited. For example, Chinese Patent 202122061569.7 discloses a rotary heat exchanger anti-clogging system based on ring-based circulating heating. The heat exchanger rotor is divided into multiple concentric rings, and the cold medium in each ring can be independently adjusted via ring-based regulating gates. When the flow rate of the cold medium in one ring is reduced, the wall temperature of the corresponding ring's heat exchange element increases, and the rings vaporize at different times to form acidic liquid that blocks ash, periodically loosening the accumulated ash. This system actually requires adjusting the flow rate of the cold medium in multiple fan-shaped areas of different shapes. Due to the inability of conventional baffle gates to be installed on irregular cross-sections and insufficient installation space on the lower end face of the rotary heat exchanger, a more complex irregularly shaped transition duct needs to be designed, shaping the cold medium inlet into a rectangle and then installing a rectangular damper. This process increases implementation costs, and sometimes there is no space available on-site for installing rectangular dampers. Furthermore, leakage from the rectangular damper can limit the increase in the wall temperature of the heat exchange element, affecting the anti-clogging effect. Therefore, in order to adapt to various application scenarios in industrial sites, it is urgent to develop new types of airflow regulating doors. Summary of the Invention

[0008] To address the problems of existing air volume regulating doors requiring large installation space, being inconvenient to design in irregular shapes, changing airflow direction during adjustment, having poor flow regulation characteristics, and still having leakage after closing, this invention provides a grille-type airbag-type air volume regulating door and a rotary air preheater containing it.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] A grille-type airbag-type air volume regulating door includes at least a grille-type air source distribution bracket, a strip-shaped airbag, and a door frame;

[0011] The grid-type air source distribution bracket includes a main distribution pipe, branch pipes, and strip supports. There are two or more branch pipes and strip supports, and they correspond one-to-one. Each strip support is set inside the door frame to form a grid structure. One end of the branch pipe is connected to the main distribution pipe, and the other end is connected to the corresponding strip support. Each strip support is equipped with a strip airbag. The branch pipe is connected to the inside of the strip airbag. That is, the corresponding strip airbag can be inflated or deflated by inflating or deflating the branch pipe through the main pipe. When the strip airbag is completely deflated, there is a gap between adjacent strip airbags and between adjacent strip supports. When all the strip airbags are full of gas, the inside of the door frame is blocked.

[0012] The inside of the door frame is designed with a multi-airbag structure. This allows for adjustment of the inflation level of the strip-shaped airbags as needed, thereby evenly regulating the airflow through the inside of the door frame. When all the strip-shaped airbags are filled with gas, the inside of the door frame is completely sealed off, meaning there is no air leakage.

[0013] For ease of adjustment, the above-mentioned grille-type airbag-type air volume regulating gate also includes an air source pipeline, an air source device, and an air source pressure regulating valve. One end of the air source pipeline is connected to the distribution main pipe, and the other end is connected to the air source device. The air source pressure regulating valve is located on the air source pipeline.

[0014] The aforementioned gas source device must at least have the function of providing inflation (providing positive pressure). In order to improve the regulation efficiency, the gas source device of this application is preferably a device that can provide inflation and depressurization functions at the same time. The inflation (providing positive pressure) and depressurization (providing negative pressure) devices can directly adopt existing equipment; the gas source pressure regulating valve is preferably a vacuum solenoid valve, which can control positive and negative pressure at the same time.

[0015] For ease of preparation, strip-shaped supports are distributed on one or both sides of the distribution header. When the strip-shaped supports are distributed on both sides of the distribution header, each strip-shaped support and the distribution header are located inside the door frame. The strip-shaped supports on both sides of the distribution header form a grid structure. One end of the distribution header passes through the door frame and is connected to the gas source device through the gas source pipeline. The gas source pipeline is equipped with a gas source pressure regulating valve. When the strip-shaped airbags are all filled with gas, the inside of the door frame is completely blocked by the strip-shaped airbags on both sides of the distribution header.

[0016] As one implementation scheme, the strip-shaped support is located inside the corresponding strip-shaped airbag; the door frame is set horizontally, and the strip-shaped airbag is set horizontally inside the door frame. The longitudinal section of the strip-shaped support is a flat structure that is set vertically and has rounded corners. That is, the thickness of the strip-shaped support is much smaller than its height, and it has rounded corners, which can ensure the opening degree of the adjustable door.

[0017] To improve stability, the end of the strip bracket that is not connected to the branch pipe can be connected to the side wall of the door frame by bolts passing through the strip airbag, and a seal should be installed at the connection to prevent air leakage.

[0018] As another implementation, the strip-shaped support is located outside the strip-shaped airbag; the door frame is horizontally set, and the strip-shaped airbag is horizontally set inside the door frame, that is, the length direction of the strip-shaped airbag is parallel to the horizontal direction. The strip-shaped support includes two strip-shaped clamps arranged opposite each other. The top of the strip-shaped airbag is clamped between the two strip-shaped clamps along the length direction, that is, the support is on top and the airbag is below. This allows the airbag to be hung, and maintenance personnel can stand on the support; the strip-shaped clamps are connected to the side wall of the door frame through corner plates.

[0019] Angle plate is a sheet material with two sides perpendicular to each other, forming an angle. It can also be angle iron. Strip-shaped plywood can also be made of angle iron.

[0020] The aforementioned door frame can be a square structure, a trapezoidal structure, or a fan-shaped structure.

[0021] The term "fan" in this application refers to a shape formed by two arcs with the same curvature and two radial sides connecting the two ends of the arcs.

[0022] When the door frame has a fan-shaped structure, the strip support is straight and arranged radially along the door frame, in which case the cross-section of the strip airbag is triangular; alternatively, the strip support is curved and arranged circumferentially along the door frame, in which case the strip airbag is also curved. When the door frame is large, airbag support strips can be installed as needed to support the airbag and / or the strip support.

[0023] When the cross-section of the fan-shaped channel that needs to be adjusted is large, the door frame is a fan-shaped structure. The door frame is divided into two or more sub-door frames by partitions set along the circumference. Each sub-door frame has a strip-shaped support set along the radial direction on its inner side. When the strip-shaped airbags on the inner side of each sub-door frame are filled with gas, the inner side of the sub-door frame is completely sealed. Each sub-door frame corresponds to a distribution main pipe. Each distribution main pipe is located on the outer side of the long arc edge of the door frame. The strip-shaped supports in each sub-door frame pass through the corresponding branch pipes and connect to the corresponding distribution main pipe.

[0024] For ease of assembly, each distribution header is an arc parallel to the long arc side of the door frame; the branch pipes corresponding to different door frames pass through from different heights of the door frame and connect to the corresponding distribution headers.

[0025] The material used for the strip-shaped airbag in this application can be rubber or other similar materials.

[0026] A rotary air preheater has a rotor cold end face divided into N concentric rings by circumferential partitions, where N ≥ 2. At least one air compartment has N fan-shaped cold air ducts at its cold end. The cross-section of each fan-shaped cold air duct is fan-shaped, and both its upper and lower ends are fan-shaped openings. Each of the N fan-shaped cold air ducts corresponds one-to-one with one of the N concentric rings. The fan-shaped openings on the upper ends of the fan-shaped cold air ducts are matched and connected to their corresponding concentric rings. The radial sides of the fan-shaped openings on the upper ends of the fan-shaped cold air ducts are connected to the sides of the cold end fan-shaped plates within the corresponding concentric rings. The plane containing the fan-shaped openings on the upper ends of the fan-shaped cold air ducts is flush with the sealing surface of the cold end fan-shaped plates.

[0027] Each fan-shaped cold air duct is equipped with the aforementioned grille-type airbag-type air volume regulating door; the door frame is a fan-shaped structure that matches the cross-section of the corresponding fan-shaped cold air duct, and the door frame is horizontally installed on the inner side of the corresponding fan-shaped cold air duct.

[0028] The strip-shaped support is straight and arranged radially along the door frame, in which case the cross-section of the strip-shaped airbag is a triangular structure; or, the strip-shaped support is arc-shaped and arranged circumferentially along the door frame, in which case the strip-shaped airbag is also arc-shaped.

[0029] When the strip support is set radially along the door frame, the distribution main pipe is located outside the corresponding fan-shaped cold air duct. The branch pipes of the grid-type airbag-type air volume regulating door on different fan-shaped cold air ducts pass through the door frame and the side wall of the corresponding fan-shaped cold air duct from different heights and are connected to the corresponding distribution main pipe. The distribution main pipe is connected to the air source device through the air source pipeline, and the air source pipeline is equipped with an air source pressure regulating valve.

[0030] When the strip support is set along the circumference of the door frame, the distribution header is located inside the corresponding door frame or fan-shaped cold air duct. The distribution headers corresponding to different fan-shaped cold air ducts pass through the door frame and the side wall of the corresponding fan-shaped cold air duct from different sides or different heights (staggered positions) and are connected to the air source device through the air source pipeline. The air source pipeline is equipped with an air source pressure regulating valve.

[0031] The air intake volume within each fan-shaped cold air duct can be adjusted by regulating the inflation level of the strip-shaped airbags on each fan-shaped cold air duct.

[0032] When the air volume in one or more fan-shaped cold air ducts is reduced, the exhaust gas temperature on the corresponding ring flue gas side rises, and the wall temperature of the corresponding ring heat storage element increases, which vaporizes and forms acidic liquid that blocks ash. Regularly loosening the accumulated ash reduces or avoids ash blockage and corrosion.

[0033] Further optimization involves setting the distance between each grille-type airbag-type air volume regulating door and the cold end face of the air preheater rotor to be 1-3 meters.

[0034] Any techniques not mentioned in this invention are based on existing technologies.

[0035] This invention relates to a grille-type airbag-style airflow regulating gate, suitable for regulating airflow through irregular channels such as fan-shaped ones. It can be used for ring-by-ring heating in rotary heat exchangers. By adjusting the inflation level of the strip-shaped airbags inside the gate frame, the airflow passing through the inner side of the gate frame can be uniformly regulated without changing the airflow direction during adjustment. It features a simple structure, easy installation, space saving, easy adjustment, good airtightness, and low cost. Furthermore, the grille structure design ensures uniform airflow. Compared to traditional regulating gates, it not only has better adaptability and is easier to adjust and control, but also improves uniformity, saves space, and reduces costs. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a grille-type airbag-type air volume regulating door according to Embodiment 1 of the present invention;

[0037] Figure 2 This is a schematic diagram of a grille-type airbag-type airflow regulating door according to Embodiment 2 of the present invention;

[0038] Figure 3 This is a schematic diagram of the strip-shaped airbag and strip-shaped support in Embodiment 3 of the present invention;

[0039] Figure 4for Figure 3 A magnified view of the left side;

[0040] Figure 5 This is a schematic diagram of the strip-shaped airbag and strip-shaped support in Embodiment 4 of the present invention;

[0041] Figure 6 for Figure 5 Left view of the inflated state;

[0042] Figure 7 for Figure 5 Left view of the uninflated state;

[0043] Figure 8 for Figure 5 A 3D view of the inflated state;

[0044] Figure 9 for Figure 5 A 3D view of the uninflated state;

[0045] Figure 10 This is a schematic diagram of the grille-type airbag-type air volume regulating door of Embodiment 5 of the present invention;

[0046] Figure 11 This is a schematic diagram of the grille-type airbag-type air volume regulating door of Embodiment 6 of the present invention;

[0047] Figure 12 for Figure 11 A three-dimensional image;

[0048] In the diagram, 1 is a grid-shaped air source distribution bracket, 11 is a distribution main pipe, 12 is a branch pipe, 13 is a strip-shaped bracket, 2 is a strip-shaped airbag, and 3 is a door frame. Detailed Implementation

[0049] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0050] The directional terms used in this application, such as up / down, left / right, horizontal, and vertical, are all based on the horizontal placement of the door frame (e.g., ...). Figure 1 , Figure 2 The relative orientations or positional relationships shown (as indicated) should not be construed as an absolute limitation on this application.

[0051] Example 1

[0052] like Figure 1 As shown, a grille-type airbag-type airflow regulating door includes at least a grille-type air source distribution bracket, strip-shaped airbags, a door frame, air source pipes, an air source device, and an air source pressure regulating valve. The grille-type air source distribution bracket includes a main distribution pipe, branch pipes, and strip-shaped supports. The number of branch pipes and strip-shaped supports is two or more, and they correspond one-to-one. Each strip-shaped support is located inside the door frame, forming a grille structure. Figure 1 As shown, in this example, the strip supports are distributed on one side of the main distribution pipe. The door frame is a square structure, with the main distribution pipe located outside the door frame. One end of the branch pipe is connected to the main distribution pipe, and the other end passes through the door frame to connect to the corresponding strip support. Each strip support is equipped with a strip-shaped airbag. The branch pipe is connected to the inside of the strip-shaped airbag, meaning that inflation and deflation of the corresponding strip-shaped airbag can be completed by inflating or deflating the branch pipe through the main pipe. Each strip-shaped airbag is cylindrical (when inflated). The strip-shaped airbags are made of rubber. When the strip-shaped airbags are completely deflated, there is a gap between adjacent strip-shaped airbags and adjacent strip supports, and the regulating valve is in the open state. When all the strip-shaped airbags are full of gas, the inside of the door frame is blocked, and the regulating valve is in the closed state. One end of the gas source pipeline is connected to the main distribution pipe, and the other end is connected to the gas source device. The gas source pressure regulating valve is located on the gas source pipeline.

[0053] The above-mentioned design of the inner side of the door frame as a multi-airbag structure makes it easy to adjust the inflation degree of the strip airbags as needed, thereby evenly regulating the airflow through the inner side of the door frame. When all the strip airbags are full of gas, the inner side of the door frame is completely sealed, that is, there is no air leakage.

[0054] Example 2

[0055] Unlike Example 1, as follows: Figure 2 As shown, for ease of preparation, strip-shaped supports are distributed on both sides of the distribution header, forming a grid structure on both sides of the distribution header. Each strip-shaped support and the distribution header are located inside the door frame. The strip-shaped supports on both sides of the distribution header form a grid structure. One end of the distribution header passes through the door frame and is connected to the gas source device through a gas source pipeline. A gas source pressure regulating valve is provided on the gas source pipeline. When the strip-shaped airbags are all filled with gas, the inside of the door frame is completely blocked by the strip-shaped airbags on both sides of the distribution header.

[0056] Example 3

[0057] Based on Example 1 or 2, the following improvements were further made: Figure 3-4 As shown, the strip-shaped support is located inside the corresponding strip-shaped airbag; the door frame is horizontally set, and the strip-shaped airbag is horizontally set inside the door frame. The longitudinal section of the strip-shaped support is a flat structure with a vertical setting and rounded corners, meaning the thickness of the strip-shaped support is much smaller than its height, and the corners are rounded to ensure the adjustable opening degree of the door. To improve stability, the end of the strip-shaped support not connected to the branch pipe can be connected to the side wall of the door frame using bolts passing through the strip-shaped airbag, and a seal should be installed at the connection to prevent air leakage.

[0058] Example 4

[0059] Based on Example 1 or 2, the following improvements were further made: Figure 5-9As shown, the strip-shaped support is located outside the strip-shaped airbag; the door frame is horizontally set, and the strip-shaped airbag is horizontally set inside the door frame, that is, the length direction of the strip-shaped airbag is parallel to the horizontal direction. The strip-shaped support includes two strip-shaped clamps arranged opposite each other. The top of the strip-shaped airbag is clamped between the two strip-shaped clamps along the length direction, that is, the support is on top and the airbag is below. This allows the airbag to be hung, and maintenance personnel can stand on the support; the strip-shaped clamps are connected to the side wall of the door frame through corner plates.

[0060] Example 5

[0061] Unlike Example 3, as follows: Figure 10 As shown, the door frame has a fan-shaped structure, and the strip-shaped support is arc-shaped and set along the circumference of the door frame. At this time, the strip-shaped airbag is also arc-shaped. When the door frame size is large, airbag support strips can be set as needed to support the airbag and / or the strip-shaped support.

[0062] Example 6

[0063] Unlike Example 3, as follows: Figure 11-12 As shown, the strip-shaped supports are straight and arranged radially along the door frame, with the cross-section of the strip-shaped airbags being triangular. In this example, the cross-section of the fan-shaped channel to be adjusted is relatively large. The door frame is divided into two sub-door frames by a partition plate arranged circumferentially. Each sub-door frame has a radially arranged strip-shaped support on its inner side. When the strip-shaped airbags on the inner side of each sub-door frame are filled with gas, the inner side of the sub-door frame is completely sealed. Each sub-door frame corresponds to a distribution header, and each distribution header is located outside the long arc-shaped side of the door frame. The strip-shaped supports in each sub-door frame pass through the corresponding branch pipes and connect to the corresponding distribution header. For ease of assembly, each distribution header is arc-shaped parallel to the long arc-shaped side of the door frame; the branch pipes corresponding to different sub-door frames pass through different heights of the door frame and connect to the corresponding distribution header.

[0064] Example 7

[0065] A rotary air preheater has a rotor cold end face divided into two concentric rings of equal area by a circumferential partition. Two fan-shaped cold air ducts are provided at the cold end of at least one air compartment. The cross-section of the fan-shaped cold air ducts is fan-shaped, and both the upper and lower ends of the fan-shaped cold air ducts are fan-shaped openings. The two fan-shaped cold air ducts correspond one-to-one with the two concentric rings. The fan-shaped openings on the upper ends of the fan-shaped cold air ducts are matched and connected to their corresponding concentric rings. The two radial sides of the fan-shaped openings on the upper ends of the fan-shaped cold air ducts are connected to the sides of the cold end fan-shaped plates in the corresponding concentric rings. The plane where the fan-shaped openings on the upper ends of the fan-shaped cold air ducts are located is flush with the sealing surface of the cold end fan-shaped plates.

[0066] Each sector-shaped cold air duct is equipped with a grid-type airbag-type air volume regulating valve; the distance between each grid-type airbag-type air volume regulating valve and the cold end face of the air preheater rotor is 1.5 meters, so that the air preheater can be inspected and maintained while standing on the regulating valve when the air preheater is not in operation.

[0067] In this example, the grille-type airbag-type air volume regulating door differs from that in Example 3 in that the door frame is a fan-shaped structure that matches the cross-section of the fan-shaped cold air duct, and the door frame is horizontally installed inside the corresponding fan-shaped cold air duct.

[0068] like Figure 10-12 As shown, the strip support is straight and arranged radially along the door frame, in which case the cross-section of the strip airbag is a triangular structure; or, the strip support is arc-shaped and arranged circumferentially along the door frame, in which case the strip airbag is also arc-shaped.

[0069] like Figure 11-12 As shown, when the strip support is set radially along the door frame, the distribution header is located on the outside of the corresponding fan-shaped cold air duct. The branch pipes of the grid-type airbag-type air volume regulating door on different fan-shaped cold air ducts pass through the door frame and the side wall of the corresponding fan-shaped cold air duct from different heights and are connected to the corresponding distribution header. The distribution header is connected to the air source device through the air source pipeline, and the air source pipeline is equipped with an air source pressure regulating valve.

[0070] like Figure 10 As shown, when the strip bracket is installed along the circumference of the door frame, the distribution header is located inside the corresponding door frame or fan-shaped cold air duct. The distribution headers corresponding to different fan-shaped cold air ducts pass through the door frame and the side wall of the corresponding fan-shaped cold air duct from different heights and are connected to the air source device through the air source pipeline. The air source pipeline is equipped with an air source pressure regulating valve. The air source device adopts an existing device that can provide both inflation and deflation functions. The air source pressure regulating valve adopts a vacuum solenoid valve.

[0071] The air intake volume within each fan-shaped cold air duct can be adjusted by regulating the inflation level of the strip-shaped airbags on each fan-shaped cold air duct.

[0072] When the air volume in one or more fan-shaped cold air ducts is reduced, the exhaust gas temperature on the corresponding ring flue gas side rises, and the wall temperature of the corresponding ring heat storage element increases. This causes the acid liquid that forms the ash to be blocked to vaporize. Regularly loosening the ash can reduce or avoid ash blockage and corrosion.

[0073] The above-described grille-type airbag-type airflow regulating gates are suitable for regulating airflow in irregular channels such as fan-shaped ones. They can be used for ring-by-ring heating in rotary heat exchangers. By adjusting the inflation level of the strip-shaped airbags inside the gate frame, the airflow passing through the inside of the gate frame can be evenly adjusted without changing the airflow direction. The gates are simple in structure, easy to install, space-saving, easy to adjust, have good airtightness, and low cost. Furthermore, the grille structure design ensures uniform airflow. Compared to traditional regulating gates, they are not only more adaptable and easier to adjust and control, but also improve uniformity, save space, and reduce costs.

Claims

1. A grille-type airbag-type airflow regulating door, characterized in that: It includes at least a grille-type air source distribution bracket (1), a strip-shaped airbag (2), and a door frame (3); The grid-type air source distribution bracket (1) includes a distribution main pipe (11), branch pipes (12) and strip brackets (13); the number of branch pipes (12) and strip brackets (13) are both more than two and correspond one to one. Each strip bracket (13) is set inside the door frame (3) to form a grid structure; one end of the branch pipe (12) is connected to the distribution main pipe (11) and the other end is connected to the corresponding strip bracket (13); each strip bracket (13) is equipped with a strip air bag (2), and the branch pipe (12) is connected to the inside of the strip air bag (2); when the strip air bag (2) is in a completely deflated state, there is a gap between adjacent strip air bags (2) and between adjacent strip brackets (13); when the strip air bags (2) are filled with gas, the inside of the door frame (3) is blocked. The door frame (3) is a square structure, a trapezoidal structure or a fan-shaped structure; When the door frame (3) is a fan-shaped structure, the strip support (13) is straight and is set along the radial direction of the door frame (3), and the cross-section of the strip airbag (2) is a triangular structure; or, the strip support (13) is arc-shaped and is set along the circumference of the door frame (3), and the strip airbag (2) is an arc-shaped column. The door frame (3) is a fan-shaped structure. The door frame (3) is divided into two or more sub-door frames (3) by partitions arranged along the circumference. Each sub-door frame (3) has a radially arranged strip support (13) on its inner side. When the strip airbags (2) on the strip support (13) on the inner side of each sub-door frame (3) are filled with gas, the inner side of the sub-door frame (3) is completely sealed. Each sub-door frame (3) corresponds to a distribution main pipe (11). Each distribution main pipe (11) is located on the outer side of the long arc edge of the door frame (3). The strip support (13) in each sub-door frame (3) passes through the corresponding branch pipe (12) and connects to the corresponding distribution main pipe (11). Each distribution main pipe (11) is an arc shape parallel to the long arc side of the door frame (3); the branch pipes (12) corresponding to different door frames (3) pass out from different heights of the door frame (3) and connect to the corresponding distribution main pipes (11).

2. The grille-type airbag-type airflow regulating door as described in claim 1, characterized in that: It also includes a gas source pipeline, a gas source device and a gas source pressure regulating valve. One end of the gas source pipeline is connected to the distribution main pipe (11) and the other end is connected to the gas source device. The gas source pressure regulating valve is located on the gas source pipeline.

3. The grille-type airbag-type airflow regulating door as described in claim 1, characterized in that: Strip supports (13) are distributed on one or both sides of the distribution main pipe (11); when the strip supports (13) are distributed on both sides of the distribution main pipe (11), the strip supports (13), the distribution main pipe (11), the door frame (3), each strip support (13) and the distribution main pipe (11) are located inside the door frame (3), the strip supports (13) on both sides of the distribution main pipe (11) form a grid structure, one end of the distribution main pipe (11) passes through the door frame (3) and is connected to the gas source device through the gas source pipeline, the gas source pipeline is equipped with a gas source pressure regulating valve, when the strip air bags (2) are filled with gas, the inside of the door frame (3) is completely blocked by the strip air bags (2) on both sides of the distribution main pipe (11).

4. The grille-type airbag-type airflow regulating door as described in any one of claims 1-3, characterized in that: The strip support (13) is located inside the strip airbag (2); the door frame (3) is set horizontally, the strip airbag (2) is set horizontally inside the door frame (3), and the longitudinal section of the strip support (13) is a flat structure with vertical setting and rounded corner transition.

5. The grille-type airbag-type airflow regulating door as described in any one of claims 1-3, characterized in that: The strip support (13) is located outside the strip airbag (2); the door frame (3) is horizontally set, and the strip airbag (2) is horizontally set inside the door frame (3). The strip support (13) includes two strip clamps arranged opposite each other. The top of the strip airbag (2) is clamped between the two strip clamps along the length direction. The strip clamps are connected to the side wall of the door frame (3) through corner plates.

6. A rotary air preheater, wherein the cold end face of the air preheater rotor is divided into N concentric rings by circumferential partitions, where N≥2, characterized in that: N fan-shaped cold air ducts are installed at the cold end of at least one air compartment. The cross-section of the fan-shaped cold air duct is fan-shaped, and both the upper and lower ends of the fan-shaped cold air duct are fan-shaped openings. The N fan-shaped cold air ducts correspond one-to-one with N concentric rings. The fan-shaped openings on the upper ends of the fan-shaped cold air ducts are matched and connected to their corresponding concentric rings. The two radial sides of the fan-shaped openings on the upper ends of the fan-shaped cold air ducts are connected to the sides of the cold end fan-shaped plates in the corresponding concentric rings. The plane where the fan-shaped openings on the upper ends of the fan-shaped cold air ducts are located is flush with the sealing surface of the cold end fan-shaped plates. Each fan-shaped cold air duct is provided with a grille-type airbag-type air volume regulating door as described in any one of claims 1-5; the door frame (3) is a fan-shaped structure that matches the cross-section of the fan-shaped cold air duct, and the door frame (3) is horizontally installed on the inner side of the corresponding fan-shaped cold air duct. The strip support (13) is straight and is set radially along the door frame (3), at which time the cross-section of the strip airbag (2) is a triangular structure; or, the strip support (13) is arc-shaped and is set circumferentially along the door frame (3), at which time the strip airbag (2) is an arc-shaped column. When the strip support (13) is set radially along the door frame (3), the distribution main pipe (11) is located on the outside of the corresponding fan-shaped cold air pipe. The branch pipes (12) of the grid-type airbag-type air volume regulating door on different fan-shaped cold air pipes pass through the door frame (3) and the side wall of the corresponding fan-shaped cold air pipe from different heights and are connected to the corresponding distribution main pipe (11). The distribution main pipe (11) is connected to the air source device through the air source pipeline. The air source pipeline is equipped with an air source pressure regulating valve. When the strip support (13) is set along the circumference of the door frame (3), the distribution header (11) is located inside the corresponding door frame (3) or fan-shaped cold air pipe. The distribution header (11) corresponding to different fan-shaped cold air pipes passes through the door frame (3) and the side wall of the corresponding fan-shaped cold air pipe from different sides or different heights, and is connected to the gas source device through the gas source pipeline. The gas source pipeline is equipped with a gas source pressure regulating valve. By adjusting the inflation level of the strip-shaped airbags (2) on each fan-shaped cold air duct, the air intake volume in the corresponding fan-shaped cold air duct can be adjusted.

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