Plate-type air pre-heater
By adopting heat exchange plate and spoiler rod structures in the plate air preloader, the problem of low heat exchange efficiency of flue gas is solved, more efficient heat exchange and more uniform temperature distribution are achieved, and the stability and heat transfer effect of the equipment are enhanced.
Patent Information
- Application Number
- CN202422272422.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-09-18
AI Technical Summary
The flue gas heat exchange efficiency in the existing air preloader is low, and it is impossible to use the heat of the flue gas at the tail of the boiler to heat the air entering the boiler to the maximum extent, resulting in low heat exchange efficiency.
A plate air preloader is designed, adopting a multi-piece heat exchange plate and a first spoiler rod structure, and the flue gas is disturbed by the arrangement of a spoiler at the welding site, so that the high-temperature flue gas is mixed with the low-temperature flue gas, enhance convection and heat dissipation, and optimize the shape and distribution of the flue gas channel.
It improves the flue gas heat exchange efficiency, reduces local overheating or supercooling, enhances the heat transfer effect between the flue gas and the heat exchange plate, reduces the difficulty of manufacturing and installation, and improves the stability and heat exchange efficiency of the equipment.
Smart Images
Figure CN223137920U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of air preheaters, in particular to a plate type air preheater. Background Art
[0002] An air preheater (referred to as an air preheater for short) is a heat exchange device used to improve the thermal efficiency of a boiler. The main function of the air preheater is to use the heat of the flue gas discharged from the tail flue of the boiler to heat the air entering the boiler. On the one hand, this can reduce the flue gas discharge temperature, reduce the heat loss of flue gas discharge, and improve the boiler efficiency; on the other hand, the heated air enters the furnace to participate in combustion, which can increase the combustion temperature, stabilize the combustion process, reduce the loss of incomplete combustion of fuel, and at the same time improve the radiation heat transfer intensity in the furnace. There are various types of air preheaters, such as rotary air preheaters, tubular air preheaters, etc. The rotary air preheater has the advantages of compact structure, small volume, high heat exchange efficiency, etc., and is widely used in large-scale power station boilers.
[0003] When the air preheater in the prior art utilizes the heat of the flue gas discharged from the tail flue of the boiler, it is impossible to make the high-temperature flue gas contact and heat the air entering the boiler to the greatest extent. There is a situation where the temperature of the flue gas at the edge decreases, while the flue gas in the middle part remains at a high temperature, resulting in low heat exchange efficiency. Summary of the Utility Model
[0004] In order to overcome the deficiency of low flue gas heat exchange efficiency in the prior art, the utility model provides a plate type air preheater, which can solve the problem of low flue gas heat exchange efficiency.
[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme: a plate type air preheater, including a casing, a plurality of heat exchange plates are connected in the casing at intervals in the front-rear direction, a flue gas channel is formed between two adjacent heat exchange plates, a plurality of welding parts are arranged on the heat exchange plates, the non-welded parts of the heat exchange plates are far away from each other to form a gas flow cavity, at least one first spoiler rod is arranged on at least one welding part of at least one heat exchange plate, one end of the first spoiler rod is fixedly connected with the welding part, and the other end of the first spoiler rod abuts against the adjacent heat exchange plate.
[0006] After adopting the above technical solution, the utility model has the following advantages: In the flue gas passage in the flue gas travel direction, the hot-side medium is in a variable cross-section state. Among them, at the welding part, that is, the expansion part of the flue gas passage, the flue gas flow velocity is relatively low and the heat exchange efficiency is relatively low. Therefore, at the welding part, a certain number of first spoiler rods are arranged to disturb the flue gas, so that the relatively high-temperature part inside the flue gas is disturbed and mixed with the relatively low-temperature part, enabling the high-temperature part to directly contact the heat exchange plate, which can enhance the convective heat release of the flue gas on the flue gas side to the heat exchange plate. And only one end of the first spoiler rod is fixedly connected to the heat exchange plate, and the other end is not fixedly connected to the heat exchange plate, so that the occupied volume of the heat exchange plate during storage and transportation can be reduced. Since the fixing work at the other end is reduced, the assembly is more convenient.
[0007] Further, the cross-section of some of the first spoiler rods in the front-back direction is in the shape of a water droplet, with the small end facing the direction of flue gas inflow and the large end facing the direction of flue gas outflow.
[0008] Adopting the foregoing technical solution, by designing the cross-section of the first spoiler rod into the shape of a water droplet, the water droplet-shaped cross-section is more streamlined than the traditional circular or square cross-section. When the flue gas flows through the water droplet-shaped spoiler column, it can more effectively guide the flue gas flow, generating more complex and intense turbulence. The enhancement of this turbulence helps to improve the mixing degree of the flue gas with the surrounding medium, further promoting the heat transfer and mass transfer processes, making the heat distribution of the new gas mass more uniform. After flowing down and hitting another first spoiler rod, it will experience turbulence and mixing again, enhancing the convection and release of the flue gas heat.
[0009] Further, when the heat exchange plates are arranged in a staggered manner, for example: the installation heights of adjacent heat exchange plates are inconsistent, or the heat exchange plates are inclined, at this time, the cross-section shape of the first spoiler rod near the inflow of the flue gas passage in the front-back direction is in the shape of a shuttle, with the two small ends facing the direction of flue gas flow.
[0010] Adopting the foregoing technical solution, when the heat exchange plates are arranged in a staggered manner, the flow path of the flue gas passage is more complex, increasing the turbulence degree of the fluid, thereby improving the heat exchange efficiency. At the same time, it will also greatly reduce the flue gas flow velocity. Therefore, the shape of the first spoiler rod is designed into a shuttle shape. By designing the cross-section of the first spoiler rod into a shuttle shape, the spoiler column with a shuttle-shaped cross-section has a more streamlined shape, which can better guide the flue gas flow. When the flue gas passes through the shuttle-shaped spoiler column, the flow field is smoother, reducing the flow resistance. At the same time, it can split and mix the flue gas, which helps to improve the heat exchange efficiency of the flue gas and enhance the convection and release of the flue gas heat.
[0011] Further, a plurality of first spoiler rods are fixed on the heat exchange plate. The first spoiler rod has a first cross-section perpendicular to the front-back direction, and at least some of the first cross-sections of the first spoiler rods are different from each other.
[0012] Adopting the foregoing technical solution, by arranging more than two first spoiler rods on the heat exchange plate, the flue gas can be further disturbed when flowing through the flue gas passage, so that the flue gas changes into fluids with different speeds when passing through the first spoiler rods with different cross-sectional shapes, and multiple groups of turbulences formed after the spoiler will interact and mix with each other, making the overall temperature distribution more uniform, greatly improving the heat exchange efficiency, and reducing the phenomenon of overheating in some places and overcooling in some places.
[0013] Furthermore, a second spoiler rod is further included. The second spoiler rod is arranged at the inlet of the flue gas passage, and the front and rear ends of the second spoiler rod are fixed to the casing.
[0014] Adopting the foregoing technical solution, by arranging the second spoiler rod at the inlet of the flue gas passage, the incoming flue gas can be preliminarily shunted and disturbed. After the flue gas contacts the second spoiler rod, the flow direction will change, so that the flue gas is more evenly distributed in each flue gas passage, which helps to improve the heat exchange efficiency of the entire heat exchanger and avoid local overheating or overcooling.
[0015] Furthermore, the first spoiler rod is fixed to the welding part by welding.
[0016] Adopting the foregoing technical solution, when manufacturing the plate air preheater, the first spoiler rod can also be welded to the heat exchange plate while welding the heat exchange plate, simplifying the manufacturing process and reducing the manufacturing cost.
[0017] Furthermore, a third spoiler rod is further included. The third spoiler rod is also arranged on the welding part, and the lengths of the third spoiler rods arranged on the welding part are at least two.
[0018] Adopting the foregoing technical solution, the third spoiler rods with different lengths, that is, the distances between the third spoiler rods and the heat exchange plate are different. When the flue gas passes through the third spoiler rods with different lengths, the flue gas passage will be further divided into different small channels, and when the flue gas passes through these small channels, it will also be affected and disturbed to different degrees. When passing through the third spoiler rod that is not in tight contact with the heat exchange plate, there will be two kinds of flue gas with different flow rates, and they will affect, act on and merge with each other, making the spoiler effect of the flue gas better and further improving the heat exchange efficiency.
[0019] Furthermore, the welding part is divided into a first welding ring and a second welding ring. The first welding ring and the second welding ring are arranged alternately, and the first spoiler rod is fixed on the first welding ring.
[0020] Furthermore, the welding part is divided into a first welding ring and a second welding ring. The first welding ring and the second welding ring are arranged alternately, and the first spoiler rod is fixed on the first welding ring.
[0021] By adopting the foregoing technical solution, by fixing the first spoiler rod on the first welding ring, it is possible to increase the spoiler effect of the first spoiler rod on the flue gas as much as possible while reducing costs.
[0022] Further, the surface of the heat exchange plate in the flue gas passage is provided with concave and convex textures.
[0023] By adopting the foregoing technical solution, the concave and convex textures provided on the surface of the heat exchange plate help to increase the heat exchange area and improve the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The following further describes the present invention with reference to the accompanying drawings:
[0025] Figure 1 It is a schematic diagram of a plate type air preheater of the present invention;
[0026] Figure 2 It is a three-dimensional schematic diagram of the heat exchange plate;
[0027] Figure 3 It is a schematic diagram of the first spoiler rod being in a water droplet shape or a shuttle shape Figure 1 ;
[0028] Figure 4 It is a schematic diagram of the first spoiler rod being in a water droplet shape or a shuttle shape Figure 2 ;
[0029] Figure 5 It is a schematic diagram when the heat exchange plates are staggered.
[0030] BRIEF DESCRIPTION OF THE DRAWINGS: 1. Housing; 2. Heat exchange plate; 21. Welding part; 211. Through hole; 22. Gas flow cavity; 3. Flue gas passage; 4. First spoiler rod; 5. Third spoiler rod. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.
[0032] In the description and claims of the present utility model, terms such as "first", "second", etc. (if any) are used to distinguish similar objects, rather than to describe a specific order or sequence. Even if "second" is used to distinguish a certain technical feature, it does not necessarily imply the existence of "first". It should be understood that in the present utility model, "including" and "having" and any of their variations are intended to cover non-exclusive inclusion. It should be understood that in the present utility model, "a plurality of" means two or more. "And / or" is merely a description of the relationship between related objects, indicating that three relationships may exist. For example, X and / or Y may represent three situations: X exists alone, X and Y exist simultaneously, and Y exists alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "Including X, Y, and Z" and "including X, Y, Z" mean that all of X, Y, and Z are included. "Including X, Y, or Z" means that one of X, Y, and Z is included. "Including X, Y
[0033] and / or Z" means that any one or any two or all three of X, Y, and Z are included.
[0034] The technical solution of the present utility model will be described in detail below with specific embodiments. These specific embodiments can be combined or replaced according to the actual situation. For the same or similar concepts or processes, they may not be described again in some embodiments.
[0035] Embodiment 1:
[0036] As Figures 1 to 5 shown, the present utility model provides a plate type air preheater, including a casing 1. A plurality of heat exchange plates 2 are connected in the casing 1 at intervals in the front-rear direction. A flue gas passage 3 is formed between two adjacent heat exchange plates 2. A plurality of welding parts 21 are provided on the heat exchange plates 2. The non-welded parts 21 of the heat exchange plates 2 are far away from each other to form a gas flow cavity 22. At least one first spoiler rod 4 is provided on at least one of the welding parts 21 of at least one heat exchange plate 2. One end of the first spoiler rod 4 is fixedly connected to the welding part 21, and the other end of the first spoiler rod 4 abuts against the adjacent heat exchange plate 2.
[0037] After adopting the above technical solution, the utility model has the following advantages: In the direction of the flue gas travel, the flue gas passage 3 has a variable cross-sectional state. At the position of the welding part 21, that is, the expansion part of the flue gas passage 3, the flue gas flow velocity is relatively low and the heat exchange efficiency is relatively low. Therefore, at the welding part 21, a certain number of first spoiler bars 4 are provided to disturb the flue gas, so that the relatively high-temperature part inside the flue gas is disturbed and mixed with the relatively low-temperature part, enabling the high-temperature part to directly contact the heat exchange plate 2, which can enhance the convective heat release of the flue gas on the flue gas side to the heat exchange plate 2. And only one end of the first spoiler bar is fixedly connected to the heat exchange plate, and the other end is not fixedly connected to the heat exchange plate, so that the occupied volume of the heat exchange plate during storage and transportation can be reduced. Since the fixing work at the other end is reduced, the assembly is more convenient.
[0038] Specifically, the processing technology of the first spoiler bar 4 can adopt the form of porcelain ring fusion welding rivets. The length of the first spoiler bar 4 can be determined according to design requirements. When the length of the first spoiler bar 4 with equal pitch of the plate is adopted, it can also play a role in positioning and fixing the plate.
[0039] Furthermore, the first spoiler bar 4 is fixedly connected to the welding part 21 by welding.
[0040] Adopting the foregoing technical solution, when manufacturing the plate type air preheater, the first spoiler bar 4 can be welded on the heat exchange plate 2 while welding, which simplifies the manufacturing process and reduces the manufacturing cost.
[0041] Furthermore, a second spoiler bar is further included. The second spoiler bar is also arranged at the inlet of the flue gas passage 3, and the front and rear ends of the second spoiler bar are fixedly connected to the casing 1.
[0042] Adopting the foregoing technical solution, arranging the second spoiler bar at the inlet of the flue gas passage 3 can preliminarily shunt and disturb the incoming flue gas. After the flue gas contacts the second spoiler bar, the flow direction will change, so that the flue gas is more evenly distributed in each flue gas passage 3, which helps to improve the heat exchange efficiency of the entire heat exchanger and avoid local overheating or overcooling.
[0043] As Figure 5 shown: The third spoiler bar 5 is also arranged on the welding part, and the lengths of the third spoiler bars
[0044] 5 arranged on the welding part are at least two.
[0045] With the foregoing technical solution, the distances between the first spoiler rods of different lengths, i.e., the third spoiler rods 5 and the heat exchange plate, are different, and not all of them are in tight contact with the heat exchange plate. When the flue gas passes through the third spoiler rods 5 of different lengths, the flue gas passage will be further divided into different small channels. When the flue gas passes through these small channels, it will also be affected and disturbed to different degrees. When passing through the third spoiler rods 5 that are not in tight contact with the heat exchange plate, there will be two velocities of flue gas, which will affect, act on and merge with each other, making the spoiler effect of the flue gas better and further improving the heat exchange efficiency.
[0046] Further, the welded part is the first welding ring and the second welding ring, the first welding ring and the second welding ring are arranged in an alternating manner, and the first spoiler rod is fixed on the first welding ring.
[0047] With the foregoing technical solution, by fixing the first spoiler rod on the first welding ring, it is possible to increase the spoiler effect of the first spoiler rod on the flue gas as much as possible while reducing the cost.
[0048] Further, the surface of the heat exchange plate in the flue gas passage is provided with concave and convex textures.
[0049] With the foregoing technical solution, the concave and convex textures provided on the surface of the heat exchange plate help to increase the heat exchange area and improve the heat exchange efficiency.
[0050] Embodiment 2:
[0051] The difference from Embodiment 1 is that: the welded part 21 is provided with through holes 211, the third spoiler rods 5 are arranged through the adjacent front and rear through holes 211 and are fixedly connected thereto, the third spoiler rods 5 protrude from the heat exchange plate 2 in the front-rear direction, and the heat exchange plates 2 provided with the third spoiler rods 5 and the heat exchange plates 2 not provided with the third spoiler rods 5 are arranged in an alternating manner.
[0052] With the foregoing technical solution, through holes 211 are provided on the welded part 21, and the third spoiler rods 5 are arranged through and fixedly connected thereto, which increases the structural strength of the welded part 21. The third spoiler rods 5 can share a part of the pressure and impact force generated by the flue gas flow, reduce the stress concentration of the welded part 21, and reduce the risk of cracks or damage to the welded part 21. By providing through holes 211 on the welded part 21, the third spoiler rods 5 can be conveniently arranged through and installed on the adjacent front and rear heat exchange plates 2. This design makes the installation of the third spoiler rods 5 simpler and faster, reducing the installation time and workload.
[0053] Embodiment 3:
[0054] On the basis of Embodiment 1, the first spoiler rod 4 has a first cross-section perpendicular to the front-rear direction. The first cross-section of a part of the first spoiler rod 4 is in the shape of a water droplet, with the small end facing the direction of flue gas inflow and the large end facing the direction of flue gas outflow.
[0055] Adopting the foregoing technical solution, by designing the cross-section of the first spoiler rod 4 into the shape of a water droplet, the water-droplet cross-section is more streamlined than the traditional circular or square cross-section. When the flue gas flows through the water-droplet spoiler column, it can more effectively guide the flue gas flow, generating more complex and intense turbulence. The enhancement of this turbulence helps to improve the mixing degree of the flue gas with the surrounding medium, further promoting the heat transfer and mass transfer processes, making the heat distribution of the new gas mass more uniform. After flowing down and hitting another first spoiler rod 4, it undergoes turbulence and mixing again, enhancing the convection and release of the flue gas heat.
[0056] Specifically, another part of the first spoiler rod 4 is cylindrical.
[0057] Embodiment 4:
[0058] On the basis of Embodiment 1, when the heat exchange plates are arranged in a staggered manner, for example: the installation heights of adjacent heat exchange plates are inconsistent, or the heat exchange plates are inclined. At this time, the first spoiler rod 4 has a first cross-section perpendicular to the front-rear direction. The first cross-section of a part of the first spoiler rod 4 is in the shape of a spindle, with the two small ends facing the direction of flue gas flow.
[0059] Adopting the foregoing technical solution, by designing the cross-section of the first spoiler rod 4 into the shape of a spindle, the spoiler column with a spindle cross-section has a more streamlined shape, which can better guide the flue gas flow. When the flue gas passes through the spindle spoiler column, the flow field is smoother, reducing local turbulence and eddy currents, lowering the flow resistance, and at the same time being able to split and mix the flue gas, which helps to improve the heat exchange efficiency of the flue gas and enhances the convection and release of the flue gas heat.
[0060] Specifically, another part of the first spoiler rod 4 is cylindrical.
[0061] Embodiment 5:
[0062] On the basis of Embodiment 3 and Embodiment 4, a plurality of first spoiler rods 4 are fixed on the heat exchange plate 2. The first spoiler rod 4 has a first cross-section perpendicular to the front-rear direction, and at least part of the first cross-sections of the first spoiler rods 4 are different from each other.
[0063] Adopting the foregoing technical solution, by arranging more than two types of first spoiler rods 4 on the heat exchange plate, the flue gas can be further disturbed when flowing through the flue gas channel, so that the flue gas changes into fluids with different speeds when passing through the first spoiler rods 4 with different cross-sectional shapes, and multiple groups of turbulences formed after the spoiler will interact with each other and mix with each other, making the overall temperature distribution more uniform, greatly improving the heat exchange efficiency, and reducing the phenomenon of overheating in some places and overcooling in some places.
[0064] Summary:
[0065] Principle: In the flue gas travel direction of the flue gas channel, due to the existence of the welding part and the gas flow chamber, the hot-side medium is in a variable cross-section state. The flue gas flow velocity at the welding part is relatively low, and the heat exchange efficiency is low. The arrangement of the first spoiler rod can disturb the flue gas, mix the part with high temperature inside the flue gas with the part with low temperature, make the part with high temperature directly contact the heat exchange plate, enhance the convective heat release of the flue gas side to the heat exchange plate, and thus improve the heat exchange efficiency.
[0066] The functions of the plate air preheater include:
[0067] Improve heat exchange efficiency: Through the disturbance of the first spoiler rod, make the flue gas temperature distribution more uniform, improve the mixing degree of the flue gas and the surrounding medium, promote the heat transfer and mass transfer processes, enhance the convection and release of the flue gas heat, greatly improve the heat exchange efficiency, and reduce the phenomenon of overheating in some places and overcooling in some places.
[0068] Improve stability: The two ends of the first spoiler rod are respectively fixedly connected to the adjacent front and rear welding parts, which can make the two adjacent front and rear heat exchange plates more stable, prevent the deformation of the heat exchange plate, and increase the stability.
[0069] Optimize flue gas distribution: Set the first spoiler rod at the inlet of the flue gas channel, which can preliminarily split and disturb the incoming flue gas, make the flue gas more evenly distributed in each flue gas channel, improve the heat exchange efficiency of the entire heat exchanger, and avoid local overheating or overcooling.
[0070] In terms of material selection, more advanced high-temperature resistant and corrosion-resistant materials can be used to manufacture the heat exchange plate and the first spoiler rod, extend the service life of the equipment, and reduce the maintenance cost. At the same time, optimize the surface structure of the heat exchange plate and the first spoiler rod,
[0071] Increase the surface roughness or use special coatings to improve the heat transfer efficiency.
[0072] The design improvement of the first spoiler rod also includes: adopting an adjustable first spoiler rod, and making it able to automatically adjust the angle or position according to the changes of the flue gas flow rate and temperature during operation through a mechanical structure to achieve a better spoiler effect and further improve the heat exchange efficiency.
[0073] Optimize the shape of the flue gas passage: Through machining or improved design, make the shape of the flue gas passage more reasonable, reduce the resistance of flue gas flow, increase the flow rate and uniformity of flue gas, thereby optimizing the flue gas distribution and enhancing the heat exchange effect.
[0074] Adopt a new sealing technology: Adopt a more effective sealing structure between the heat exchange plate and the casing and between the heat exchange plates to reduce flue gas leakage, improve the heat exchange efficiency, and at the same time reduce energy loss.
[0075] Optimize the heat exchange plate structure: Increase the concave-convex texture on the surface of the heat exchange plate to increase the heat exchange area and improve the heat exchange efficiency.
[0076] A first spoiler rod can also be provided in the gas flow chamber to increase the mixing and heat exchange efficiency of the air in the gas flow chamber.
[0077] In addition to the above preferred embodiments, the present utility model has other implementation manners. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection claimed by the present utility model.
Claims
1. A plate-type air preheater, comprising a casing, wherein a plurality of heat exchange plates arranged at intervals in the front-rear direction are connected inside the casing, a flue gas passage is formed between two of the heat exchange plates, a plurality of welding parts are provided on the heat exchange plates, and the non-welded parts of the heat exchange plates are away from each other to form a gas flow cavity, characterized in that, At least one of the welding parts of at least one of the heat exchange plates is provided with a first spoiler bar. One end of the first spoiler bar is fixedly connected to the welding part, and the other end of the first spoiler bar abuts against an adjacent heat exchange plate.
2. The plate type air preheater according to claim 1, wherein The cross-section of a part of the first spoiler bar in the front-rear direction is in the shape of a water droplet, with the small end facing the direction of flue gas inflow and the large end facing the direction of flue gas outflow.
3. A plate type air preheater according to claim 1, characterized in that, When the heat exchange plates are arranged in a staggered pattern, the cross-section shape of the first spoiler bar near the inflow of the flue gas passage in the front-rear direction is in the shape of a shuttle, with the two small ends facing the direction of flue gas flow.
4. A plate type air preheater according to claim 1, wherein, A plurality of first spoiler bars are fixed on the heat exchange plate. The first spoiler bar has a first cross-section perpendicular to the front-rear direction, and at least part of the first cross-sections of the first spoiler bars are different from each other.
5. A plate type air preheater according to claim 1, characterized in that It further includes a second spoiler bar, which is arranged at the inlet of the flue gas passage, and the front and rear ends of the second spoiler bar are fixed to the casing.
6. The plate - type air preheater according to claim 1, wherein, It further includes a third spoiler bar, which is also arranged on the welding part, and there are at least two lengths of the third spoiler bar arranged on the welding part.
7. A plate type air preheater according to claim 1, characterized in that, The first spoiler bar is fixedly connected to the welding part by welding.
8. A plate type air preheater according to claim 1, characterized in that, The welding part is divided into a first welding ring and a second welding ring, and the first welding ring and the second welding ring are arranged in an alternating manner. The first spoiler bar is fixed on the first welding ring.
9. The plate type air preheater according to claim 1, wherein The outer surface of the heat exchange plate is provided with concave-convex textures.