A combined air preheater system

Abstract

The utility model discloses a kind of composite air preheater systems, belong to the technical field of flue gas treatment equipment, solve the problem that the flue gas outlet section and air inlet section of air preheater due to being arranged on two sides lead to larger land range and are not conducive to the space layout of multiple groups of composite air preheater systems in factory, the technical scheme for solving the problem mainly includes rotary air preheater, heat exchanger, flue gas pipeline and air pipeline, rotary air preheater is located above heat exchanger, flue gas pipeline is communicated rotary air preheater and heat exchanger, air pipeline is communicated heat exchanger and rotary air preheater, flue gas pipeline includes the flue gas outlet passage communicated with the smoke outlet of heat exchanger, air pipeline includes air inlet passage, the air inlet passage of air inlet passage and the outlet end of flue gas outlet passage are located on the same side of heat exchanger.The utility model mainly reduces the land range of air preheater, facilitate the space layout of multiple groups of composite air preheater systems in factory, improve the compactness of layout.

Description

Technical Field

[0001] This utility model relates to the technical field of flue gas treatment equipment, and in particular to a composite air preheater system. Background Technology

[0002] Industrial fuel combustion exhaust gases often contain a large amount of heat energy. Traditional methods of treatment involve directly releasing this heat-rich flue gas into the air through conventional boilers, resulting in significant energy waste and the direct release of toxic substances into the air, causing direct environmental damage. With industrial development and increased energy awareness, improving energy efficiency has become crucial, leading to the development of heat exchangers that convert heat from flue gas into water or air for reuse. The heat exchange principle involves introducing a medium to be heated into the channels of an air preheater, while heat-rich flue gas flows between the air preheaters. The flue gas heats the medium in the air preheater, achieving heat exchange, and the heated medium can then be drained out as needed.

[0003] Existing flue gas air preheater systems mainly include a rotary air preheater, a heat exchanger, a flue gas passage, and an air passage. Both the flue gas passage and the air passage are connected to the rotary air preheater and the heat exchanger. In the flue gas passage, the flue gas first enters the rotary air preheater for heat exchange, and then enters the heat exchanger for further heat exchange. In the air passage, the air first enters the heat exchanger to exchange heat with the lower-temperature flue gas, and then enters the rotary heat exchanger to exchange heat with the higher-temperature flue gas. When setting up the flue gas passage and the air passage, in order to ensure that the flue gas flows out smoothly from the outlet section of the flue gas passage and that the air enters the heat exchanger smoothly from the inlet section of the air passage, the outlet section of the flue gas passage and the inlet section of the air passage are usually located on opposite sides of the heat exchanger. This results in a large overall footprint for the air preheater, which is inconvenient for the spatial layout of multiple combined air preheater systems in the factory. Utility Model Content

[0004] The purpose of this invention is to provide a composite air preheater system that solves the problem that the separate flue gas outlet section and air inlet section of the air preheater occupy a large area, which is not conducive to the spatial layout of multiple composite air preheater systems in the factory. This reduces the footprint of the air preheater, facilitates the spatial layout of multiple composite air preheater systems in the factory, and improves the compactness of the layout.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a composite air preheater system, comprising a rotary air preheater, a heat exchanger, a flue gas duct, and an air duct. The rotary air preheater is located above the heat exchanger. The flue gas duct connects the rotary air preheater and the heat exchanger, with flue gas first entering the rotary air preheater and then the heat exchanger. The air duct connects the heat exchanger and the rotary air preheater, with air first entering the heat exchanger and then the rotary air preheater. The flue gas duct includes a flue gas outlet channel connected to the flue gas outlet of the heat exchanger. The air duct includes an air inlet channel, with the inlet end of the air inlet channel and the outlet end of the flue gas outlet channel located on the same side of the heat exchanger.

[0006] Furthermore, the flue gas outlet channel includes a main outlet channel and two sub-outlet channels. The two sub-outlet channels are connected to the flue gas outlet of the heat exchanger and are located on both sides of the air inlet channel. The main outlet channel is connected to the flue gas outlet of the two sub-outlet channels.

[0007] Furthermore, the flue gas outlet channel includes a main outlet channel and two sub-outlet channels, the air inlet channel includes two sub-inlet channels, the two sub-outlet channels are connected to the flue gas outlet of the heat exchanger and are alternately distributed with the two sub-inlet channels, and the main outlet channel is connected to the flue gas outlet of the two sub-outlet channels.

[0008] Furthermore, the air intake channel also includes an air intake concentrator channel, which is located between the two sub-intake channels and the heat exchanger. One end of the air intake concentrator channel is connected to the two sub-intake channels, and the other end is connected to the air inlet of the heat exchanger, so that the air from the two sub-intake channels can be combined in the air intake concentrator channel.

[0009] Furthermore, the air intake manifold is provided with guide plates for guiding the air entering the air intake manifold, and multiple guide plates are arranged at horizontal intervals.

[0010] Furthermore, the flue gas duct also includes a first flue gas passage connected to the flue gas inlet of the rotary air preheater and a second flue gas passage for conveying flue gas from the rotary air preheater to the heat exchanger. An auxiliary flue gas passage is provided between the first flue gas passage and the second flue gas passage to introduce the higher temperature flue gas in the first flue gas passage into the second flue gas passage.

[0011] Furthermore, the auxiliary flue gas passage is provided with a flue gas outlet pipe at its outlet end. The flue gas outlet pipe is funnel-shaped along its flue gas flow direction. The connection between the flue gas outlet pipe and the second flue gas passage is located in the middle part of the second flue gas passage. A control switch is provided on the auxiliary flue gas passage.

[0012] Furthermore, a guide plate is provided inside the flue gas outlet pipe, and the guide plate extends inclinedly toward the heat exchanger along the flue gas flow direction.

[0013] Furthermore, the guide plate is provided in multiple pieces, which are distributed along the flue gas flow direction in the second flue gas channel, and the multiple guide plates divide the flue gas outlet channel into multiple sub-channels.

[0014] As can be seen from the above, the composite air preheater system provided by this utility model optimizes the pipeline layout structure and reduces the equipment footprint by arranging the air intake channel and flue gas outlet channel on the same side of the heat exchanger. At the same time, the airflow distribution uniformity is improved through the alternating distribution of multiple channels and the flow guiding design. It has the advantages of improving space utilization and facilitating installation and maintenance. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of a composite air preheater system according to the present invention; Figure 2 This is a schematic diagram of the flue gas outlet channel of this utility model; Figure 3 This is a schematic diagram showing the alternating distribution of two sub-outlet channels and two sub-inlet channels in this utility model; Figure 4 This is a schematic diagram of the air intake and collection channel in this utility model; Figure 5 This is a schematic diagram of the heat exchanger in this utility model; Figure 6 This is a schematic diagram of the auxiliary flue gas passage in this utility model; Figure 7 This is a schematic diagram of the control switch and guide plate of this utility model. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0017] The terms "first," "second," etc. (if present) in the specification and claims of this utility model are used to distinguish similar objects, not to describe a specific order or sequence. Even if "second" is used before a technical feature for distinction, it does not necessarily imply the presence of "first." It should be understood that in this utility model, "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. It should be understood that in this utility model, "multiple" refers to two or more. "And / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, X and / or Y can represent: X alone, X and Y simultaneously, and Y alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "Containing X, Y, and Z," "Containing X, Y, and Z" means that all three X, Y, and Z are included; "Containing X, Y, or Z" means that one of X, Y, and Z is included; "Containing X, Y, and / or Z" means that any one, two, or three of X, Y, and Z are included.

[0018] The technical solution of this utility model will be described in detail below with specific embodiments. The following specific embodiments can be selected to be combined or substituted with each other according to the actual situation, and the same or similar concepts or processes may not be described again in some embodiments.

[0019] like Figure 1As shown, this utility model provides a composite air preheater system, including a rotary air preheater 1, a heat exchanger 2, a flue gas duct 3, and an air duct. The rotary air preheater 1 is located above the heat exchanger 2. The flue gas duct 3 connects the rotary air preheater 1 and the heat exchanger 2, with flue gas first entering the rotary air preheater 1 and then the heat exchanger 2. The air duct connects the heat exchanger 2 and the rotary air preheater 1, with air first entering the heat exchanger 2 and then the rotary air preheater 1. The flue gas duct 3 includes a flue gas outlet channel 31 connected to the flue gas outlet of the heat exchanger 2. The air duct includes a... The air inlet of heat exchanger 2 is connected to air intake channel 41, and the inlet end of air intake channel 41 and the outlet end of flue gas outlet channel 31 are located on the same side of heat exchanger 2. The rotary air preheater 1 is located above heat exchanger 2, meaning that the two are arranged in a layered manner in the vertical direction. Specifically, the rotary air preheater 1 can be fixed to the top of heat exchanger 2 using a support structure, utilizing the vertical space to reduce the horizontal footprint. The outlet end of flue gas outlet channel 31 and the inlet end of air intake channel 41 are located on the same side, meaning that they are arranged on the same side of heat exchanger 2. Because the flue gas outlet channel 31 and the air intake channel are concentrated on the same side, the lateral space required for the original separate arrangement is compressed, reducing the overall width of the system. In the vertical direction, the layered structure of rotary air preheater 1 and heat exchanger 2 further optimizes space utilization, forming a three-dimensional layout. Compared with the existing method of separating flue gas outlet channel 31 and air intake channel 41 on two sides, which leads to an increase in the lateral size of the system, this embodiment eliminates the redundant space of the two-sided channels by arranging them on the same side. Meanwhile, the vertically layered structure of the rotary air preheater 1 and heat exchanger 2 avoids horizontal expansion, allowing multiple systems to be installed side-by-side compactly, reducing plant space requirements. This solves the problem of large footprint caused by the split-side layout of the air preheater system. By arranging on the same side and vertically layering, the horizontal dimensions of the system are significantly reduced, facilitating the dense arrangement of multiple systems in a limited space and optimizing plant space utilization.

[0020] In this embodiment, as Figure 2As shown, the flue gas outlet channel 31 includes a main outlet channel 312 and two sub-outlet channels 311. The two sub-outlet channels 311 are connected to the flue gas outlet of the heat exchanger 2 and are located on both sides of the air inlet channel 41. The main outlet channel 312 is connected to the flue gas outlets of the two sub-outlet channels 311. Specifically, the main outlet channel 312 is a pipe structure that collects and discharges the flue gas from the two sub-outlet channels 311. It can be implemented using a straight pipe structure with a cross-sectional dimension larger than that of the sub-outlet channels 311. Its function is to integrate the flue gas flow path to improve discharge efficiency. The two sub-outlet channels 311 are branch pipes that are directly connected to the flue gas outlet of the heat exchanger 2. They can be implemented using a symmetrical distribution on both sides of the air inlet channel 41. Their function is to avoid spatial interference between the flue gas flow path and the air inlet channel 41. The air inlet channel 41 is a straight pipe located between the two sub-outlet channels 311. Its function is to make the air inlet path and the flue gas outlet path spatially complementary. After the flue gas is diverted from the outlet of heat exchanger 2 to two sub-outlet channels 311, it flows along both sides of the air inlet channel 41 and merges into the main outlet channel 312. Air enters heat exchanger 2 from the area between the two sub-outlet channels 311. Since the flue gas flow path is dispersed to both sides of the air inlet channel 41, there is no need to set up a bending structure to avoid the air inlet channel 41, thereby reducing the occupation of lateral space by the pipeline layout. In addition, the flue gas outlet and the air inlet channel 41 are concentrated on one side of heat exchanger 2, the lateral space is compressed, and the flue gas flow path and the air flow path form a spatial intersection, avoiding the flow resistance caused by pipeline bends.

[0021] In another embodiment, such as Figure 3 As shown, the flue gas outlet channel 31 includes a main outlet channel 312 and two sub-outlet channels 311. The air inlet channel 41 includes two sub-inlet channels. The two sub-outlet channels 311 are connected to the flue gas outlet of the heat exchanger 2 and are alternately distributed with the two sub-inlet channels. The main outlet channel 312 is connected to the flue gas outlet of the two sub-outlet channels 311. The two sub-inlet channels can be straight pipes arranged alternately with the sub-outlet channels 311 to divert the air to be heated into the heat exchanger 2. The alternating distribution means that the sub-outlet channels 311 and the sub-inlet channels are arranged at intervals on the same side of the heat exchanger 2. Specifically, one sub-outlet channel 311 is set adjacent to one sub-inlet channel, forming a spatially staggered layout. By reducing the lateral spacing between the channels, the overall structural width is compressed. When the air enters the heat exchanger 2 from the two sub-inlet channels, the sub-inlet channels and the sub-outlet channels 311 form staggered flow paths on the same side of the heat exchanger 2, and the flow directions of the flue gas and the air are complementary in space. In this embodiment, by alternately distributing the sub-outlet channel 311 and the sub-inlet channel on the same side of the heat exchanger 2, the flow paths of flue gas and air overlap and intersect in the lateral space. Without changing the counter-current heat exchange direction, the channels that were originally placed on both sides are concentrated on the same side, directly reducing the lateral size of the equipment.

[0022] In this embodiment, to ensure that air can enter the heat exchanger 2 more evenly, such as Figure 1 and Figure 4 As shown, the air intake channel 41 also includes an intake concentrator channel 42, which is located between the two sub-intake channels and the heat exchanger 2. One end of the intake concentrator channel 42 is connected to the two sub-intake channels, and the other end is connected to the air inlet of the heat exchanger 2, so that the air from the two sub-intake channels merges in the intake concentrator channel 42. Specifically, the air intake channel 41 is configured in the form of two sub-intake channels and an intake concentrator channel 42. By alternating the distribution of the two sub-intake channels and the two sub-outlet channels 311, the air intake channel 41 and the flue gas outlet channel 31 can be located on the same side of the heat exchanger 2, reducing the lateral space occupied by the pipe layout. Furthermore, the flue gas outlet and the air intake channel 41 are concentrated on one side of the heat exchanger 2, compressing the lateral space. At the same time, the flue gas flow path and the air flow path form a spatial intersection, avoiding the flow resistance caused by pipe bends. In addition, in this embodiment, as Figure 5 As shown, the heat exchanger 2 includes multiple spaced heat exchange plates 21, which are formed by welding two thin plates 211 together. The welded part of the two thin plates 211 forms a welded column, and the unwelded part forms an air cavity 212. The air intake collection channel 42 is connected to the air cavity 212. The air in the two sub-intake channels is collected through the air intake collection channel 42, so that the air in the air intake cavity 212 is relatively uniform, and the temperature of the multiple heat exchange plates 21 on the same horizontal direction is similar, ensuring that the deformation of the heat exchanger 2 is similar at all points on the same horizontal direction.

[0023] To further ensure that air enters the air cavity 212 more evenly, such as Figure 6 As shown, the intake manifold 42 is provided with guide plates 421 for guiding the air entering the intake manifold 42. Multiple guide plates 421 are arranged laterally at intervals. Specifically, the guide plates 421 are located at the air inlet of the intake manifold 42. The distance between the ends of two adjacent guide plates 421 and the sub-intake channels is the same, so that the amount of air entering the adjacent two guide plates 421 is basically the same, thereby ensuring that the air is relatively uniform in the intake manifold 42, so that the amount of air entering each air cavity 212 is equal.

[0024] Because the flue gas from burning coal contains a large amount of sulfur trioxide, the ammonia injected into the flue gas during the flue gas treatment process reacts with the sulfur trioxide to form ammonium bisulfate. When the flue gas enters heat exchanger 2 to exchange heat with the air, the temperature of the flue gas is relatively low. The ammonium bisulfate in the flue gas easily adheres to the heating surface of heat exchanger 2 and adsorbs fly ash particles from the flue gas, potentially causing blockage, corrosion, and wear on the heating surface of heat exchanger 2. In another embodiment, such as... Figure 1 and Figure 6As shown, the flue gas duct 3 includes a first flue gas passage 32 connected to the flue gas inlet of the rotary air preheater 1 and a second flue gas passage 33 that transports flue gas from the rotary air preheater 1 to the heat exchanger 2. An auxiliary flue gas passage 34 is provided between the first flue gas passage 32 and the second flue gas passage 33 to introduce the higher temperature flue gas in the first flue gas passage 32 into the second flue gas passage 33. The first flue gas passage 32 refers to the main flue gas transport path connecting the flue gas inlet of the rotary air preheater 1. It can be made of metal pipe or high temperature resistant composite material and is used to transport the high temperature flue gas that has not been heat-exchanged to the rotary air preheater 1 for heat exchange. The second flue gas passage 33 refers to the transport path that guides the flue gas after heat exchange in the rotary air preheater 1 to the heat exchanger 2. It can be a segmented pipe structure with a flow guide structure inside to optimize the flow distribution. The auxiliary flue gas passage 34 refers to the bypass passage that connects the first flue gas passage 32 and the second flue gas passage 33. Specifically, it can be a pipe section with an adjustable cross-sectional area, which is used to actively inject high-temperature flue gas into the second flue gas passage 33 to increase the overall temperature, thereby liquefying the ammonium bisulfate adhering to the heat-receiving surface of the heat exchanger 2 and reducing the possibility of blockage, corrosion or wear on the heat-receiving surface of the heat exchanger 2.

[0025] Furthermore, such as Figure 6 and Figure 7 As shown, the auxiliary flue gas passage 34 has a funnel-shaped flue gas outlet pipe 342 at its outlet end, which is located in the middle part of the second flue gas passage 33 along the flue gas flow direction. A control switch 341 is installed on the auxiliary flue gas passage 34. Specifically, the funnel-shaped flue gas outlet pipe 342 refers to a structure where the cross-section of the passage gradually expands along the flow direction. This can be achieved using a tapered pipe section or a gradually expanding guide hood. This structure can reduce the flue gas velocity and expand the diffusion range. The middle connection point refers to the docking position between the flue gas outlet pipe 342 and the second flue gas passage 33, located in the middle part of the passage in the flue gas flow direction of the second flue gas passage 33. This position is conducive to the uniform distribution of flue gas in the main flow path. The control switch 341 refers to an adjustable flow valve device, which can be implemented by an electric butterfly valve or a pneumatic gate valve. This device can accurately control the amount of auxiliary flue gas injected. After the flue gas completes the initial heat exchange in the rotary air preheater 1, it enters the heat exchanger 2 through the second flue gas channel 33 for secondary heat exchange.

[0026] In another embodiment, such as Figure 7As shown, a guide plate 343 is installed inside the flue gas outlet pipe 342. The guide plate 343 extends obliquely towards the heat exchanger 2 along the flue gas flow direction. The guide plate 343 is a plate-like structure installed inside the flue gas outlet pipe 342, which can be formed by welding metal plates. Its inclination angle forms an acute angle with the mainstream flue gas direction. The guide plate 343 causes the airflow to be directionally deflected by changing the flow trajectory of the flue gas. The oblique extension along the flue gas flow direction means that the guide plate 343 is installed at an angle to the horizontal plane. Specifically, it can be fixed to the inner wall of the pipe at an inclination angle of 30-60 degrees, with the inclination direction pointing towards the inlet area of ​​the heat exchanger 2. This design allows the flue gas to be guided by the surface of the guide plate 343 during the flow process. Under the guidance of the guide plate 343, the flue gas changes its original diffusion state and forms a flow path consistent with the inclination direction of the guide plate 343, improving the stability of the flue gas flow in the auxiliary flue gas channel 34 as it enters the second flue gas channel 33.

[0027] To further ensure the stability of high-temperature flue gas flow, such as Figure 7 As shown, multiple guide plates 343 are provided, distributed along the flue gas flow direction within the second flue gas channel 33. These guide plates 343 divide the flue gas outlet pipe 342 into multiple sub-channels. By dividing the flue gas flow path to form sub-channels, the guide plates 343 can perform stratified flow guidance. When the flue gas enters the outlet pipe, it is divided into multiple independently flowing sub-channels by the guide plates 343. The flue gas in each sub-channel flows in a preset direction under the constraint of the guide plates 343. The inclination angle of the guide plates 343 is consistent with the flue gas flow direction, avoiding sudden changes in local flow velocity. The distribution of the sub-channels ensures a uniform flow velocity distribution of the flue gas across the cross-section of the second flue gas channel 33, reducing turbulence or local accumulation caused by velocity differences.

[0028] In addition to the preferred embodiments described above, there are other embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection claimed by this utility model.

Claims

1. A composite air preheater system, comprising a rotary air preheater, a heat exchanger, a flue gas duct, and an air duct, wherein the rotary air preheater is located above the heat exchanger, the flue gas duct connects the rotary air preheater and the heat exchanger, the flue gas first enters the rotary air preheater and then enters the heat exchanger, and the air duct connects the heat exchanger and the rotary air preheater, the air first enters the heat exchanger and then enters the rotary air preheater, characterized in that, The flue gas duct includes a flue gas outlet channel connected to the flue gas outlet of the heat exchanger, and the air duct includes an air inlet channel, with the inlet end of the air inlet channel and the outlet end of the flue gas outlet channel located on the same side of the heat exchanger.

2. The composite air preheater system according to claim 1, characterized in that, The flue gas outlet channel includes a main outlet channel and two sub-outlet channels. The two sub-outlet channels are connected to the flue gas outlet of the heat exchanger and are located on both sides of the air inlet channel. The main outlet channel is connected to the flue gas outlet of the two sub-outlet channels.

3. The composite air preheater system according to claim 1, characterized in that, The flue gas outlet channel includes a main outlet channel and two sub-outlet channels. The air inlet channel includes two sub-inlet channels. The two sub-outlet channels are connected to the flue gas outlet of the heat exchanger and are alternately distributed with the two sub-inlet channels. The main outlet channel is connected to the flue gas outlet of the two sub-outlet channels.

4. The composite air preheater system according to claim 3, characterized in that, The air intake channel also includes an air intake concentrator channel, which is located between the two sub-intake channels and the heat exchanger. One end of the air intake concentrator channel is connected to the two sub-intake channels, and the other end is connected to the air inlet of the heat exchanger, so that the air from the two sub-intake channels can be combined in the air intake concentrator channel.

5. The composite air preheater system according to claim 4, characterized in that, The air intake manifold is equipped with guide plates for guiding the air entering the air intake manifold, and multiple guide plates are arranged at horizontal intervals.

6. The composite air preheater system according to claim 1, characterized in that, The flue gas duct also includes a first flue gas passage connected to the flue gas inlet of the rotary air preheater and a second flue gas passage for conveying flue gas from the rotary air preheater to the heat exchanger. An auxiliary flue gas passage is provided between the first flue gas passage and the second flue gas passage to introduce the higher temperature flue gas in the first flue gas passage into the second flue gas passage.

7. The composite air preheater system according to claim 6, characterized in that, The auxiliary flue gas passage has a flue gas outlet pipe at its outlet end. The flue gas outlet pipe is funnel-shaped along its flue gas flow direction. The connection between the flue gas outlet pipe and the second flue gas passage is located in the middle part of the second flue gas passage. A control switch is provided on the auxiliary flue gas passage.

8. The composite air preheater system according to claim 7, characterized in that, The flue gas outlet pipe is equipped with a guide plate, which extends inclined toward the heat exchanger along the flue gas flow direction.

9. The composite air preheater system according to claim 8, characterized in that, The guide plate is provided in multiple pieces, which are distributed along the flue gas flow direction in the second flue gas channel, and the multiple guide plates divide the flue gas outlet channel into multiple sub-channels.

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