Low-resistance anti-ash-blocking air preheater

Abstract

The invention relates to the technical field of air preheaters and discloses a low-resistance anti-ash-blocking air preheater which comprises a flue gas channel, a primary air channel, a secondary air channel, a heat storage element and an air guide pipe, the flue gas channel is used for high-temperature flue gas to pass through, the primary air channel is used for primary cold air to pass through, and the secondary air channel is used for secondary cold air to pass through. The heat storage element is used for exchanging heat with flue gas in the flue gas channel so that sulfides in the flue gas can be liquefied, the heat storage element communicates with the primary air channel and the secondary air channel, and cold air in the primary air channel and cold air in the secondary air channel can pass through the heat storage element and conduct heat exchange with the heat storage element. One end of the air guide pipe communicates with an outlet of the primary air channel, and an opening in the other end of the air guide pipe faces the heat storage element. According to the low-resistance anti-ash-blocking type air preheater, hot air of the primary air channel serves as a blowing medium, the hot air temperature is high, ammonium bisulfate with high viscosity on the heat storage element can be softened, and the adsorption capacity of the ammonium bisulfate to fly ash is reduced.

Description

Technical Field

[0001] This invention belongs to the field of air preheater technology, specifically relating to a low-resistance, anti-clogging air preheater. Background Technology

[0002] Low-resistance, anti-clogging ash-type air preheaters are a type of regenerative heat exchanger widely used in boilers of thermal power plants and other large industrial furnaces. Its core is a large, slowly rotating cylindrical or compartmented sector-shaped rotor driven by a motor, densely packed with numerous heat storage elements. The preheater shell is equipped with a sealing device, dividing the internal space into a flue gas passage and an air passage. High-temperature flue gas enters the flue gas passage from the boiler's tail flue, flows through the rotating heat storage elements, transfers heat to the elements, and is then discharged. Cool air is sent into the air passage by a fan, flows through the heated heat storage elements, absorbs heat, and its temperature rises before being sent into the furnace for combustion. The rotor rotates slowly and continuously, and the heat storage elements periodically alternate between flowing through the flue gas passage and the air passage, constantly repeating the cycle of heat absorption, rotation, and heat release.

[0003] In the air preheater of the relevant technology, sulfur trioxide in the flue gas combines with water vapor to generate sulfuric acid vapor, which in turn forms ammonium bisulfate. The generated ammonium bisulfate is liquid in the air preheater and adheres to the heat storage element. It has a very strong adhesiveness and easily captures fly ash. If it is not cleaned in time, the fly ash adhering to the surface of the heat storage element will also form hard lumps, eventually causing ash blockage. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art. To this end, embodiments of the present invention propose a low-resistance, anti-clogging air preheater, which is capable of blowing away ammonium bisulfate from the surface of the heat storage element.

[0005] The low-resistance, anti-clogging ash-type air preheater of this invention includes: A flue gas passage, wherein the flue gas passage is used for the passage of high-temperature flue gas; A primary air duct, wherein the primary air duct is used for the passage of the first cold air; A secondary air duct, wherein the secondary air duct is used for a second passage of cold air; A heat storage element is used to exchange heat with the flue gas in the flue gas passage to liquefy the sulfides in the flue gas. The heat storage element is connected to the primary air passage and the secondary air passage. The cold air in the primary air passage and the secondary air passage can pass through the heat storage element and exchange heat with the heat storage element. An air duct, one end of which is connected to the outlet of the primary air channel, and the other end of which opens toward the heat storage element; The air duct is used to direct the hot air blown out of the primary air channel to the heat storage element, thereby blowing away the liquefied sulfides on the heat storage element.

[0006] The low-resistance, anti-clogging air preheater of this invention, through the synergistic effect of the heat storage element and the flue gas channel, can absorb the heat in the high-temperature flue gas as it passes through the flue gas channel. Then, the heat storage element transfers the heat to the primary air channel and the secondary air channel to heat the first and second cold air, thereby preheating the air. The hot air in the primary air channel is used as the purging medium. The high temperature of the hot air can soften the sticky liquefied sulfides on the heat storage element and reduce its adsorption force on fly ash. Furthermore, the airflow is directed towards the heat storage elements, effectively removing adhering fly ash and preventing it from combining with liquefied sulfides to form hard lumps, thus preventing ash blockage at its source. No additional fans, heating devices, or other cleaning equipment are required; the hot air from the primary air duct is reused directly, consuming no extra energy and reducing operating costs. The cleaning function is achieved through a simple duct structure design, exhibiting strong compatibility with existing preheater structures and low modification and manufacturing difficulty. The cleaning process is synchronized with rotor rotation and heat exchange circulation, eliminating the need for shutdown for cleaning and maintaining continuous and stable preheater operation.

[0007] In some embodiments, the other end of the air duct is connected to a plurality of nozzles, the nozzle openings facing the heat storage element, and the nozzles are used to increase the blowing area of ​​the heat storage element.

[0008] In some embodiments, the other end of the air duct is connected to the inlet of the secondary air channel so that the cold air in the secondary air channel absorbs the heat from the hot air blown out by the air duct.

[0009] In some embodiments, the heat storage element includes a plurality of heat exchange plates spaced apart along the circumferential direction. The high-temperature flue gas, the primary cold air, and the secondary cold air flow through the gap between two adjacent heat exchange plates. The heat exchange plates are used to absorb heat from the high-temperature flue gas and transfer the absorbed heat to the primary cold air and the secondary cold air.

[0010] In some embodiments, a liquid sensor is provided on one side of the heat exchange plate. The liquid sensor is used to detect the distribution of liquefied sulfides on the heat exchange plate. The liquid sensor is connected to a control unit, which is used to receive the ammonium bisulfate liquid distribution signal.

[0011] In some embodiments, the air duct is provided with a control unit, the control unit including a regulating valve disposed in the air duct, the regulating valve being connected to the control unit, the control unit adjusting the opening of the regulating valve according to the distribution amount of ammonium bisulfate liquid on the heat exchange plate, thereby adjusting the air output of the nozzle.

[0012] In some embodiments, the control unit further includes a flow meter disposed in the air duct, the flow meter being used to monitor the flow rate of hot air flowing in the air duct, the flow meter being connected to the control unit, and the control unit adjusting the opening of the regulating valve according to the actual flow rate of hot air monitored by the flow meter, thereby keeping the actual flow rate of hot air consistent with the set flow rate of hot air.

[0013] In some embodiments, the control unit further includes an angle adjustment member disposed between the nozzle and the air guide duct. The control unit adjusts the angle of the angle adjustment member according to the distribution position of the ammonium bisulfate liquid on the heat exchange plate, thereby adjusting the orientation of the nozzle.

[0014] In some embodiments, the control unit further includes a thermometer disposed in the air duct, the thermometer being used to monitor the temperature of the hot air flowing in the air duct, the thermometer being connected to the control unit, and the thermometer feeding back the hot air temperature to the control unit.

[0015] In some embodiments, the control unit further includes an isolation door disposed in the air duct, the isolation door being used to control the opening and closing of the air duct. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the arrangement of the air duct in this invention.

[0017] Figure 2 This is a schematic diagram of the internal structure of the air preheater in this invention.

[0018] Figure 3 This is a schematic diagram of the air duct structure in this invention.

[0019] Figure 4 This is a schematic diagram of the installation of the air duct in this invention. Figure 1 .

[0020] Figure 5 This is a schematic diagram of the installation of the air duct in this invention. Figure 2 .

[0021] Figure label: 11. Flue gas duct; 12. Primary air duct; 13. Secondary air duct; 14. Air guide duct; 15. Nozzle; 16. Control unit; 161. Regulating valve; 162. Angle adjustment component; 163. Isolation door; 17. Connecting part; 171. Mounting plate; 172. Connecting rod. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] like Figure 1 , Figure 2 As shown, the low-resistance anti-clogging ash-type air preheater of this embodiment includes a flue gas passage 11, a primary air passage 12, a secondary air passage 13, a heat storage element, an air duct 14, and multiple nozzles 15.

[0024] Flue gas passage 11 is used for the passage of high-temperature flue gas; Primary air duct 12 is used for the first cold air to pass through; Secondary air duct 13 is used for the passage of a second cold air; The heat storage element is used to exchange heat with the flue gas in the flue gas passage 11 to liquefy the sulfides in the flue gas. The heat storage element is connected to the primary air passage 12 and the secondary air passage 13. The cold air in the primary air passage 12 and the secondary air passage 13 can pass through the heat storage element and exchange heat with the heat storage element respectively. One end of the air duct 14 is connected to the outlet of the primary air channel 12, and the other end of the air duct 14 opens towards the heat storage element. The air duct 14 is used to direct the hot air blown out of the primary air channel 12 to the heat storage element, thereby blowing away the liquefied sulfides on the heat storage element.

[0025] The low-resistance, anti-clogging air preheater of this invention, through the synergistic effect of the heat storage element and the flue gas channel, can absorb the heat in the high-temperature flue gas as it passes through the flue gas channel. Then, the heat storage element transfers the heat to the primary air channel and the secondary air channel to heat the first and second cold air, thereby preheating the air. The hot air in the primary air channel is used as the purging medium. The high temperature of the hot air can soften the sticky liquefied sulfides on the heat storage element and reduce its adsorption force on fly ash. Furthermore, the airflow is directed towards the heat storage elements, effectively removing adhering fly ash and preventing it from combining with liquefied sulfides to form hard lumps, thus preventing ash blockage at its source. No additional fans, heating devices, or other cleaning equipment are required; the hot air from the primary air duct is reused directly, consuming no extra energy and reducing operating costs. The cleaning function is achieved through a simple duct structure design, exhibiting strong compatibility with existing preheater structures and low modification and manufacturing difficulty. The cleaning process is synchronized with rotor rotation and heat exchange circulation, eliminating the need for shutdown for cleaning and maintaining continuous and stable preheater operation.

[0026] Specifically, such as Figure 1 , Figure 2As shown, during operation, high-temperature flue gas enters from above the flue gas passage 11 and exits from below. It exchanges heat with the heat storage elements within the flue gas passage 11, transferring heat to the elements. The rotor rotates slowly, and the heat storage elements periodically alternately pass through the flue gas passage 11, the primary air passage 12, and the secondary air passage 13. The first and second cold air flows through the primary air passage 12 and secondary air passage 13 respectively, passing over the heat-absorbing elements, absorbing heat and heating up before finally being sent into the furnace for combustion. The cold air in the primary air passage 12 becomes hot air after absorbing heat, and its outlet is connected to the air guide duct 14. The air guide duct 14 opens towards the heat storage elements, and the hot air directly blows onto the surface of the heat storage elements.

[0027] Furthermore, the liquefied sulfide is an ammonium bisulfate solution.

[0028] Furthermore, the low-resistance anti-clogging ash-type air preheater also includes an annular shell, in which the flue gas passage 11, primary air passage 12, and secondary air passage 13 are located. The heat storage element is rotatably installed in the shell, and partitions are provided at the upper and lower ends of the shell, which separate the flue gas passage 11, primary air passage 12, and secondary air passage 13.

[0029] Specifically, the heat storage element rotates in the housing. During the rotation, it first absorbs heat from the flue gas passage 11. Then, the part that has absorbed heat rotates with the rotor into the primary air passage 12, and then into the secondary air passage 13.

[0030] In some embodiments, such as Figure 3 As shown, the other end of the air duct 14 is connected to a plurality of nozzles 15, the nozzles 15 opening towards the heat storage element, and the nozzles 15 are used to increase the blowing area of ​​the heat storage element.

[0031] The low-resistance, anti-clogging air preheater of this invention, through the arrangement of multiple nozzles, can expand the dust removal coverage area, reduce local dead zones, and, with the spacing arrangement, achieve full-length, thorough cleaning of the heat exchange plates. This reduces the required nozzle density, eliminating the need for excessive nozzles to cover the entire area, simplifying the structure and reducing costs. The diffused airflow results in more uniform pressure, preventing localized strong impacts that could damage the heat exchange plates, while simultaneously improving overall dust removal efficiency.

[0032] Specifically, multiple nozzles 15 are spaced apart along the length of the heat exchange fins to achieve uniform coverage of the entire length of the heat exchange fins and avoid missing any local areas. The nozzles 15 have a gradually expanding opening design. After the hot air flows out of the air guide duct, the airflow diffuses along the expansion direction, increasing the spray coverage area.

[0033] In some embodiments, such as Figure 1 , Figure 2As shown, the other end of the air duct 14 is connected to the inlet of the secondary air channel 13 so that the cold air in the secondary air channel 13 can absorb the heat from the hot air blown out by the air duct 14.

[0034] The low-resistance, anti-clogging air preheater of this invention is connected to the inlet of the secondary air channel through an air duct, so that the hot air after purging will flow into the secondary air channel and continue to participate in the heat exchange of the heat storage element. The heat is not wasted, and the overall heat exchange performance of the preheater is not affected.

[0035] Specifically, such as Figure 1 , Figure 2 As shown, during use, hot air is blown towards the heat storage element through the air duct 14 and is connected to the inlet of the secondary air channel 13. The hot air after purging enters the heat storage element together with the cold air in the secondary air channel 13 for heat exchange again, without wasting heat, and at the same time completing the dust removal action.

[0036] In some embodiments, the heat storage element includes a plurality of heat exchange plates spaced apart along the circumferential direction. High-temperature flue gas, primary cold air, and secondary cold air flow through the gap between two adjacent heat exchange plates. The heat exchange plates are used to absorb heat from the high-temperature flue gas and transfer the absorbed heat to the primary and secondary cold air.

[0037] The low-resistance, anti-clogging air preheater of this invention features multiple heat exchange fins spaced circumferentially, forming numerous dense gap channels. On one hand, this significantly increases the contact area between the heat storage element and the flue gas and cold air, allowing for more efficient heat transfer. Compared to integral heat storage elements, the heat exchange fins can absorb and release heat faster, improving the heat exchange rate. On the other hand, the spaced heat exchange fin structure allows for a more uniform distribution of airflow (flue gas and cold air), preventing localized accumulation or obstruction, ensuring that each heat exchange fin fully participates in heat exchange, and guaranteeing stable overall heat exchange performance of the preheater. Furthermore, the gaps between adjacent heat exchange fins provide unobstructed paths for airflow and purging air. The hot air ejected from the nozzles can directly reach the surface of the heat exchange fins and deep into the gaps, precisely removing adhering substances. Compared to integral heat storage elements, this effectively prevents ash particles from accumulating and agglomerating in dead corners. In addition, the spaced arrangement of the heat exchange fins reduces "dead corner areas" for ash particle adhesion, lowering the probability of clogging and extending the continuous operating time of the preheater.

[0038] Specifically, a rotor is installed in the casing, and multiple heat exchange plates are evenly spaced on the rotor along the circumferential direction. When the rotor rotates, it drives the multiple heat exchange plates to rotate.

[0039] In some embodiments, a liquid sensor is provided on one side of the heat exchange plate. The liquid sensor is used to detect the distribution of ammonium bisulfate liquid on the heat exchange plate. The liquid sensor is connected to a control unit, which is used to receive the ammonium bisulfate liquid distribution signal.

[0040] The low-resistance, anti-fouling air preheater of this invention, through the installation of a liquid sensor, can detect signals as soon as ammonium bisulfate adheres and before it has captured a large amount of fly ash agglomeration. The control unit can issue timely warnings based on abnormal signals. This allows for early intervention by staff, preventing rapid fouling that could lead to blockage of heat exchanger gaps, preheater shutdown, and other sudden malfunctions, thus ensuring the stable operation of the boiler unit.

[0041] Specifically, the liquid sensor maintains continuous contact with the heat exchanger surface or operates in a non-contact monitoring manner. The liquid sensor can be a capacitive sensor, possessing a fixed static capacitance when no ammonium bisulfate liquid is present. When liquid ammonium bisulfate adheres to the heat exchanger surface and contacts the sensor, it causes a change in the sensor's capacitance value. Different areas of liquid adhesion correspond to different capacitance changes, reflecting the density of the liquid distribution. The sensor converts these detected physical signals, such as capacitance changes, into transmittable electrical signals, which are then sent in real-time to the connected control unit. The control unit continuously receives and stores these signals carrying information about the ammonium bisulfate liquid distribution, completing a closed loop from physical state to electrical signal to data information.

[0042] Furthermore, the liquid sensor and control unit are existing technologies and will not be described in detail here.

[0043] In some embodiments, such as Figure 1 , Figure 2 As shown, an adjustment unit 16 is provided on the air duct 14. The adjustment unit 16 includes an adjustment valve 161 provided in the air duct 14. The adjustment valve 161 is connected to the control unit. The control unit adjusts the opening of the adjustment valve 161 according to the distribution of ammonium bisulfate liquid on the heat exchange plate, thereby adjusting the air volume of the nozzle 15.

[0044] The low-resistance, anti-clogging air preheater of this invention allows for flexible adjustment of the airflow based on the distribution differences of ammonium bisulfate through the setting of the regulating valve. For areas with severe accumulation, a large airflow is used for efficient ash removal to prevent the formation of hard ash clogging; for areas with slight adhesion, a small airflow is used to purge, avoiding unnecessary impact and wear on the heat exchange fins caused by a large airflow.

[0045] Specifically, a liquid sensor on one side of the heat exchange fin continuously monitors the distribution of ammonium bisulfate liquid. When a large amount of ammonium bisulfate accumulates in a localized area of ​​the heat exchange fin, the sensor converts the corresponding adhesion level signal into an electrical signal and transmits it to the control unit. After receiving the signal, the control unit quickly analyzes the accumulation of ammonium bisulfate in different areas, determines which locations require strong purging and which locations can maintain regular purging, and generates corresponding airflow adjustment commands.

[0046] Furthermore, the regulating valve 161 is existing technology and will not be described in detail.

[0047] In some embodiments, the control unit 16 further includes a flow meter disposed in the air duct 14. The flow meter is used to monitor the flow rate of hot air flowing in the air duct 14. The flow meter is connected to the control unit. The control unit adjusts the opening of the regulating valve 161 according to the actual flow rate of hot air monitored by the flow meter, so as to keep the actual flow rate of hot air consistent with the set flow rate of hot air.

[0048] The low-resistance, anti-clogging air preheater of this invention only sends commands to the regulating valve through the control unit. Factors such as changes in duct resistance, fan pressure fluctuations, and pipe leaks may cause deviations between the actual airflow and the set value. Real-time feedback from the flow meter allows the control unit to dynamically correct these deviations, ensuring that the airflow from the nozzles fully meets the dust removal requirements and avoiding the problem of "insufficient airflow when strong blowing is needed, and excessive airflow (energy waste) when weak blowing is needed."

[0049] Specifically, a flow meter is installed inside the air duct to continuously monitor the actual flow rate of primary hot air passing through it. It converts the monitored airflow data (such as volumetric flow rate and mass flow rate) into electrical signals and transmits them in real time to the connected control unit. The control unit first calculates the required "set hot air volume" for the corresponding area based on the ammonium bisulfate distribution data fed back by the liquid sensor (more accumulation results in a larger set air volume, and less accumulation results in a smaller set air volume). Then, the control unit compares the "actual hot air volume" from the flow meter with the preset "set hot air volume" in real time to determine if there is a deviation (such as insufficient, excessive, or fluctuating actual air volume). When the actual air volume is detected to be less than the set value, the control unit sends an "increase opening" command to the regulating valve, widening the gap between the valve core and seat to increase the hot air flow rate in the air duct; when the actual air volume is greater than the set value, it sends a "decrease opening" command, narrowing the gap to reduce the flow rate; if the air volume fluctuates frequently, the control unit continuously fine-tunes the regulating valve opening to ensure that the actual hot air volume remains stable within the set value range.

[0050] Furthermore, flow meters are existing technology and will not be discussed further.

[0051] In some embodiments, such as Figure 3 As shown, the control unit 16 also includes an angle adjustment component 162 disposed between the nozzle 15 and the air duct 14. The control unit adjusts the angle of the angle adjustment component 162 according to the distribution position of the ammonium bisulfate liquid on the heat exchange plate, thereby adjusting the orientation of the nozzle 15.

[0052] The low-resistance, anti-clogging air preheater of this invention addresses the issue that traditional fixed-direction nozzles struggle to cover the entire area of ​​the heat exchange plates (such as edges, deep gaps, and blind spots in the rotor's rotation trajectory), easily creating cleaning dead zones. The angle adjustment component allows the nozzles to flexibly adjust their direction, ensuring precise targeting and purging regardless of where ammonium bisulfate accumulates on the heat exchange plates, thoroughly removing deposits from dead zones and eliminating the risk of clogging from a spatial perspective.

[0053] Specifically, the liquid sensor on one side of the heat exchange plate not only monitors the distribution of ammonium bisulfate, but also accurately identifies the specific location of the accumulation (such as the upper or lower part of the heat exchange plate, a certain sector, or deep in the gap) by the sensor's placement position (such as multiple points along the circumference or radial direction of the heat exchange plate), and transmits the position signal to the control unit in real time. After receiving the position signal, the control unit calculates the optimal nozzle orientation angle required to align with the accumulation location by combining the rotation speed of the heat exchange plate and the nozzle installation position (e.g., if the accumulation is on the left side of the heat exchange plate, the nozzle is adjusted to deflect to the left; if the accumulation is deep in the gap, the nozzle is adjusted to tilt inward). At the same time, it coordinates with the flow meter and regulating valve to determine the required air volume and synchronously generates "angle adjustment command" and "air volume adjustment command". After receiving the angle command from the control unit, the angle adjustment component 162 drives the nozzle 15 to rotate or swing around the connection point, changing the spray direction of the nozzle 15 to ensure that the nozzle 15 opening is accurately aligned with the target area of ​​ammonium bisulfate accumulation. After the angle is adjusted to the correct position, the regulating valve 161 maintains a stable airflow according to the set air volume, and the nozzle 15 sprays hot air towards the target location, directly impacting the ammonium bisulfate accumulation area.

[0054] Furthermore, the angle adjustment element 162 includes, but is not limited to, existing technologies such as an angle adjustment motor capable of adjusting the direction of the nozzle 15.

[0055] In some embodiments, the control unit 16 further includes a thermometer disposed in the air duct 14. The thermometer is used to monitor the temperature of the hot air flowing in the air duct 14. The thermometer is connected to the control unit and feeds back the hot air temperature to the control unit.

[0056] The low-resistance, anti-clogging air preheater of this invention continuously monitors the actual temperature of the primary hot air flowing through it by setting a temperature gauge installed in the air duct, and transmits the temperature signal to the control unit in real time, providing a temperature dimension basis for judging the dust removal effect.

[0057] Furthermore, the thermometer is existing technology and will not be described in detail.

[0058] In some embodiments, such as Figure 2 As shown, the control unit 16 also includes an isolation door 163 disposed in the air duct 14, which is used to control the opening and closing of the air duct 14.

[0059] The low-resistance, anti-clogging air preheater of this invention reduces energy waste by using an isolation door. When ash removal is not required, the isolation door can be closed to prevent continuous hot air leakage or empty blowing. Furthermore, it ensures maintenance safety; the isolation door can quickly cut off airflow, providing a safe environment for the maintenance of components such as air ducts and nozzles.

[0060] Specifically, during normal dust removal, the control isolation door 163 is opened, the air duct is unobstructed, and hot air is blown in a directional and quantitative manner through the nozzles after passing through the regulating valve and flow meter. When dust removal is not required, the control unit instructs the isolation door 163 to close, cutting off the airflow in the air duct and preventing the ineffective loss of hot air. During equipment maintenance, the isolation door 163 can be closed manually or through the control unit to isolate the air duct from the system and ensure maintenance safety.

[0061] Furthermore, the isolation door 163 is existing technology and will not be described in detail.

[0062] In some embodiments, such as Figure 4 , Figure 5 As shown, the air duct 14 is connected to a connecting part 17, which includes a mounting plate 171 and a connecting rod 172.

[0063] The mounting plate 171 is U-shaped and is connected to the air duct 14. The mounting plate 171 is used to support the air duct 14. Multiple connecting rods 172 are provided. One end of the connecting rod 172 is connected to the mounting plate 171, and the other end of the connecting rod 172 is connected to the air preheater. The connecting rod 172 is used to connect the air duct 14 and the air preheater.

[0064] The low-resistance, anti-clogging air preheater of this invention ensures dust removal stability through the design of the connecting parts. Multi-point fixing of the connecting parts prevents vibration or displacement of the air duct, ensuring the nozzle blowing direction and position remain precise and do not affect the directional and quantitative dust removal effect. Furthermore, it simplifies installation and maintenance. The U-shaped mounting plate fits snugly against the air duct and the connecting rod connects to the main body, making installation and disassembly convenient. Subsequent maintenance of the air duct does not require extensive disassembly of the preheater's internal structure.

[0065] Specifically, the U-shaped mounting plate 171 is directly connected to the air duct 14. Utilizing the fit and support of the U-shaped structure, it provides stable support for the air duct 14, preventing it from shifting due to airflow impact or equipment vibration. Multiple connecting rods 172 are connected at one end to the mounting plate 171 and at the other end to the air preheater body, forming a multi-point fixing structure that firmly anchors the air duct 14 to the preheater, ensuring that the nozzle 15 is always aimed at the target purging area of ​​the heat storage element.

[0066] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0067] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0068] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0069] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0070] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0071] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A low-resistance, anti-clogging air preheater, characterized in that, include: Flue gas passage (11), the flue gas passage (11) is used for the passage of high temperature flue gas; A primary air duct (12) is provided for the passage of the first cold air. Secondary air passage (13), the secondary air passage (13) is used for the passage of a second cold air; A heat storage element is used to exchange heat with the flue gas in the flue gas passage (11) to liquefy the sulfides in the flue gas. The heat storage element is connected to the primary air passage (12) and the secondary air passage (13). The cold air in the primary air passage (12) and the secondary air passage (13) can pass through the heat storage element and exchange heat with the heat storage element. Air duct (14), one end of which is connected to the outlet of the primary air channel (12), and the other end of which opens toward the heat storage element; The air duct (14) is used to direct the hot air blown out of the primary air channel (12) to the heat storage element, thereby blowing away the liquefied sulfides on the heat storage element.

2. The low-resistance, anti-clogging air preheater according to claim 1, characterized in that, The other end of the air duct (14) is connected to a plurality of nozzles (15), the nozzles (15) opening toward the heat storage element, and the nozzles (15) are used to increase the blowing area of ​​the heat storage element.

3. The low-resistance, anti-clogging air preheater according to claim 1, characterized in that, The other end of the air duct (14) is connected to the inlet of the secondary air channel (13) so that the cold air in the secondary air channel (13) can absorb the heat in the hot air blown out by the air duct (14).

4. The low-resistance, anti-clogging air preheater according to claim 2, characterized in that, The heat storage element includes a plurality of heat exchange plates spaced apart along the circumference. The high-temperature flue gas, the primary cold air, and the secondary cold air flow through the gap between two adjacent heat exchange plates. The heat exchange plates are used to absorb heat from the high-temperature flue gas and transfer the absorbed heat to the primary cold air and the secondary cold air.

5. The low-resistance, anti-clogging air preheater according to claim 4, characterized in that, A liquid sensor is provided on one side of the heat exchange plate. The liquid sensor is used to detect the distribution of liquefied sulfides on the heat exchange plate. The liquid sensor is connected to a control unit, which is used to receive the ammonium bisulfate liquid distribution signal.

6. The low-resistance, anti-clogging air preheater according to claim 5, characterized in that, The air duct (14) is provided with a control unit (16), the control unit (16) includes a regulating valve (161) provided in the air duct (14), the regulating valve (161) is connected to the control unit, the control unit adjusts the opening of the regulating valve (161) according to the distribution amount of ammonium bisulfate liquid on the heat exchange plate, thereby adjusting the air volume of the nozzle (15).

7. The low-resistance, anti-clogging air preheater according to claim 6, characterized in that, The control unit (16) also includes a flow meter installed in the air duct (14). The flow meter is used to monitor the flow rate of hot air flowing in the air duct (14). The flow meter is connected to the control unit. The control unit adjusts the opening of the regulating valve (161) according to the actual flow rate of hot air monitored by the flow meter, so as to keep the actual flow rate of hot air consistent with the set flow rate of hot air.

8. The low-resistance, anti-clogging air preheater according to claim 5, characterized in that, The control unit (16) also includes an angle adjustment member (162) disposed between the nozzle (15) and the air guide pipe (14). The control unit adjusts the angle of the angle adjustment member (162) according to the distribution position of the ammonium bisulfate liquid on the heat exchange plate, thereby adjusting the orientation of the nozzle (15).

9. The low-resistance, anti-clogging air preheater according to claim 6, characterized in that, The control unit (16) also includes a thermometer installed in the air duct (14). The thermometer is used to monitor the temperature of the hot air flowing in the air duct (14). The thermometer is connected to the control unit and feeds back the hot air temperature to the control unit.

10. The low-resistance, anti-clogging air preheater according to claim 6, characterized in that, The control unit (16) also includes an isolation door (163) disposed in the air duct (14), the isolation door (163) being used to control the opening and closing of the air duct (14).

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