Air preheater
By introducing a cyclone dust removal device and honeycomb ceramic heat storage body into the air preheater, the problem of dust in the flue gas affecting heat exchange is solved, and the heat exchange efficiency of the air preheater and the thermal efficiency of the boiler are improved.
Patent Information
- Application Number
- CN202420754907.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-11
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-04-11
AI Technical Summary
During the use of existing air preheaters, because the boiler flue gas contains a lot of floating dust, it is easy to stick to the heat exchange tube, which will affect the heat exchange effect and difficulty in cleaning, affecting the efficiency of the preheater.
An air preheater including a heat exchange device and a dust removal device is designed. The high-temperature flue gas is dust-removed by a cyclone separator. The clean flue gas enters the heat exchange tube and exchanges heat with the cold air. At the same time, it is in the heat exchange tube. A honeycomb ceramic heat storage body is installed to absorb and release heat, increasing the heat exchange area and efficiency.
It effectively avoids smoke and dust blocking the heat exchange pipe, improves heat exchange efficiency, extends the maintenance and cleaning time of the heat exchange pipe, and improves the thermal efficiency and fuel utilization of the boiler.
Smart Images
Figure CN222230585U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of preheating recovery, in particular to an air preheater. Background Art
[0002] Air preheater, also referred to as air preheater, is a preheating device that improves boiler heat exchange performance and reduces heat loss. The function of the air preheater is to transfer the heat carried by the flue gas discharged from the tail flue of the boiler to the air before entering the boiler through the heat sink, and preheat the air to a certain temperature.
[0003] During the use of the existing air preheater, since the flue gas of the boiler contains a large amount of floating dust, when passing through the heat exchange tube, it is easy to adhere to the inner wall of the heat exchange tube during the heat exchange process, affecting the heat exchange effect. Not only is it troublesome to clean it later, but it also affects the heat exchange efficiency of the preheater. Utility Model Content
[0004] The technical problem to be solved by the utility model is how to prevent smoke from blocking the heat exchange tubes of the air preheater.
[0005] The utility model solves the above technical problems through the following technical means: an air preheater, including a heat exchange device and a dust removal device; the heat exchange device includes a heat exchange chamber and a cold air inlet and a hot air outlet respectively arranged at both ends of the heat exchange chamber, and a heat exchange tube is arranged in the heat exchange chamber; the dust removal device is connected to the inlet end of the heat exchange tube. The heat exchange device can recycle the waste heat of the flue gas, thereby reducing the exhaust loss, and the thermal efficiency of the boiler can be improved when the hot air is used for combustion again; after the dust removal device pre-treats the high-temperature flue gas to remove dust, it can effectively avoid the smoke from clogging the heat exchange tube, and can also avoid the smoke from attaching to the tube wall in large quantities to affect the heat exchange efficiency.
[0006] As an optimized technical solution, the dust removal device adopts a cyclone separator, and the dust removal device includes a separation chamber, an air inlet pipe, an air outlet pipe and a dust outlet. The air inlet pipe, the air outlet pipe and the dust outlet are all arranged on the separation chamber, and the air outlet pipe is connected to the inlet end of the heat exchange tube. The dust removal device separates the smoke and dust in the flue gas by using the cyclone dust removal principle. The separated smoke and dust are discharged from the dust removal device through the dust outlet. The clean smoke moves along the separation chamber until it leaves from the air outlet pipe, and then the high-temperature clean smoke enters the heat exchange tube, exchanges heat with the cold air in the heat exchange device, and then leaves the heat exchange tube.
[0007] As an optimized technical solution, the air inlet pipe is arranged at the upper part of the side wall of the separation chamber, the air outlet pipe is arranged at the central area of the top wall of the separation chamber, the dust outlet is arranged at the bottom of the separation chamber, and the heat exchange device is arranged above the dust removal device. Clean high-temperature flue gas can quickly enter the heat exchange tube, thereby reducing the pressure drop of flue gas flow.
[0008] As an optimized technical solution, the air preheater also includes a first flow guide chamber, which is arranged between the dust removal device and the heat exchange tube, and the inner cavity size of the first flow guide chamber gradually increases from the dust removal device to the heat exchange tube. The first flow guide chamber can diffuse the high-temperature flue gas from the relatively small outlet pipe to a larger space, which is conducive to the high-temperature flue gas entering multiple heat exchange tubes evenly, thereby facilitating the increase in the number of heat exchange tubes and the heat exchange area of the heat exchange chamber to improve the heat exchange efficiency of the heat exchange chamber, and also avoid the situation where the flue gas concentrates on entering the heat exchange tubes in some areas, causing heat accumulation. In addition, the heat exchange tube with a larger coverage area can also fully extend the heat exchange time between the cold air and the heat exchange tube, and improve the heat exchange amount.
[0009] As an optimized technical solution, a plurality of first guide plates and a plurality of second guide plates are arranged in the first guide chamber, and the first guide plates and the second guide plates are arranged at intervals from top to bottom; a plurality of first guide plates are arranged in a row, and an angle is formed between each first guide plate and the Y direction of the horizontal plane, and the angle between the first guide plates in the middle and the two sides and the horizontal plane changes uniformly; a plurality of second guide plates are arranged in a row, and an angle is formed between each second guide plate and the X direction of the horizontal plane, and the angle between the second guide plates in the middle and the two sides and the horizontal plane changes uniformly. The combination of the first guide plate and the second guide plate is arranged to facilitate the uniform diffusion of high-temperature flue gas.
[0010] As an optimized technical solution, the air preheater further includes a second flow guide chamber, which is arranged between the cold air inlet and the heat exchange chamber, and the inner cavity size of the second flow guide chamber gradually increases from the cold air inlet to the heat exchange chamber. The second flow guide chamber can diffuse the cold air to the vertical surface of the heat exchange chamber, thereby increasing the contact surface between the cold air and the heat exchange tube and improving the heat exchange efficiency.
[0011] As an optimized technical solution, a plurality of third guide plates are arranged in a row in the second guide chamber, and each third guide plate forms an angle with the Z direction of the vertical plane, and the angles between the third guide plates in the middle and the vertical plane on both sides change evenly. The third guide plates are provided to facilitate uniform diffusion of cold air.
[0012] As an optimized technical solution, the air preheater further includes a slow flow chamber, which is arranged between the hot air outlet and the heat exchange chamber, and the inner cavity size of the slow flow chamber gradually decreases from the heat exchange chamber to the hot air outlet. The slow flow chamber can slow down the air flow, preventing the heat exchange air from passing through the heat exchange chamber quickly, thereby extending the heat exchange time between the air and the heat exchange tube and increasing the heat exchange amount.
[0013] As an optimized technical solution, a plurality of slow flow plates are provided in the slow flow chamber, and the slow flow plates are folded plates, and the inner angle of the folded plates faces one side of the heat exchange chamber. The structure of the slow flow plates can effectively slow down the air flow.
[0014] As an optimized technical solution, a heat storage body is provided in the heat exchange tube, and the heat storage body adopts a honeycomb ceramic heat storage body. After the heat storage body is added in the heat exchange tube, the heat storage body can continuously absorb and release heat, thereby improving the heat exchange quality and reducing the influence of flue gas temperature fluctuation on air heat exchange; in addition, the use of honeycomb ceramic heat storage body can utilize its porous thin wall characteristics to greatly increase the geometric surface area and thermal shock resistance of the carrier, and the evenly distributed through holes of the honeycomb ceramic heat storage body will not intercept the rare impurities in the clean flue gas, which is conducive to extending the maintenance and cleaning time of the heat exchange tube.
[0015] The advantages of the utility model are:
[0016] 1. The heat exchange device can recycle the waste heat of flue gas, thereby reducing the exhaust loss. When the hot air is used for combustion again, the thermal efficiency of the boiler can be improved. After the dust removal device pre-treats the high-temperature flue gas, it can effectively prevent the smoke from clogging the heat exchange tubes, and can also prevent the smoke from attaching to the tube wall in large quantities, affecting the heat exchange efficiency.
[0017] 2. The first guide chamber allows the high-temperature flue gas to diffuse from a relatively small exhaust pipe to a larger space, which is conducive to the high-temperature flue gas to evenly enter multiple heat exchange tubes, thereby increasing the number of heat exchange tubes and increasing the heat exchange area of the heat exchange chamber to improve the heat exchange efficiency of the heat exchange chamber, and avoid the situation where the flue gas concentrates on entering the heat exchange tubes in some areas and causes heat accumulation. In addition, the heat exchange tubes with a larger coverage area can also fully extend the heat exchange time between the cold air and the heat exchange tubes and increase the heat exchange amount.
[0018] 3. The second guide chamber can diffuse the cold air to the vertical surface of the heat exchange chamber, thereby increasing the contact surface between the cold air and the heat exchange tube and improving the heat exchange efficiency.
[0019] 4. The slow flow chamber can slow down the air flow and prevent the heat exchange air from passing through the heat exchange chamber quickly, thereby extending the heat exchange time between the air and the heat exchange tube and increasing the heat exchange amount.
[0020] 5. After adding a heat storage body in the heat exchange tube, the heat storage body can continuously absorb and release heat, thereby improving the heat exchange quality and reducing the impact of flue gas temperature fluctuations on air heat exchange; in addition, the use of honeycomb ceramic heat storage body can take advantage of its porous thin wall characteristics to greatly increase the geometric surface area and thermal shock resistance of the carrier, and the evenly distributed through holes of the honeycomb ceramic heat storage body will not intercept rare impurities in the clean flue gas, which is conducive to extending the maintenance and cleaning time of the heat exchange tube. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a schematic structural diagram of an air preheater according to an embodiment of the utility model. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described in combination with the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the utility model.
[0023] like Figure 1 As shown, an embodiment of the utility model discloses an air preheater, including a heat exchange device 1, a dust removal device 2, a first flow guide chamber 3, a second flow guide chamber 4, a slow flow chamber 5 and a heat storage body 6.
[0024] The heat exchange device 1 comprises a heat exchange chamber 11 and a cold air inlet 12 and a hot air outlet 13 respectively arranged at two ends of the heat exchange chamber 11 . Heat exchange tubes 14 are evenly arranged in the heat exchange chamber 11 .
[0025] The dust removal device 2 adopts a cyclone separator for cyclone dust removal. The dust removal device 2 includes a separation chamber 21, an air inlet pipe 22, an air outlet pipe 23 and a dust outlet 24; the air inlet pipe 22 is arranged on the upper part of the side wall of the separation chamber 21, and the air outlet pipe 23 is arranged at the central area of the top wall of the separation chamber 21. The air outlet pipe 23 is connected to the inlet end of the heat exchange tube 14; the dust outlet 24 is arranged at the bottom of the separation chamber 21 to discharge the smoke in the smoke.
[0026] The heat exchange device 1 is arranged above the dust removal device 2, so that the clean high-temperature flue gas can smoothly pass through the outlet pipe 23 and quickly enter the heat exchange tube 14, thereby reducing the pressure drop of the flue gas flow.
[0027] When in use, the smoke in the flue gas is separated by the dust removal device 2, and the separated smoke is discharged from the dust removal device 2 through the dust outlet 24. The clean smoke moves upward along the center position of the separation chamber 21 until it leaves from the outlet pipe 23, and then the high-temperature clean smoke enters the heat exchange tube 14, exchanges heat with the cold air in the heat exchange device 1, and then leaves the heat exchange tube 14; at the same time, the cold air entering from the cold air inlet 12 exchanges heat at the heat exchange tube 14, and then leaves from the hot air outlet 13. Therefore, the waste heat of the flue gas can be recovered and utilized through the heat exchange device 1, thereby reducing the exhaust loss, and the thermal efficiency of the boiler can be improved when the hot air is used for combustion again; and when the air temperature rises by 1.5°C in the air preheater, the exhaust temperature can be reduced by 1°C. After installing the air preheater in the boiler flue, if the air can be heated to 150-160°C, the exhaust temperature can be reduced by 110-120°C, thereby increasing the thermal efficiency of the boiler by 7%-7.5% and saving 11%-12% of fuel; after the high-temperature flue gas is pre-treated by the dust removal device 2 for dust removal, the problem of smoke blocking the heat exchange tube 14 can be effectively solved, and the heat exchange efficiency can be prevented from being affected by a large amount of smoke adhering to the tube wall.
[0028] The first guide chamber 3 is arranged between the outlet pipe 23 and the heat exchange tube 14, and the inner cavity size of the first guide chamber 3 gradually increases from the outlet pipe 23 to the heat exchange tube 14; a plurality of first guide plates 31 and a plurality of second guide plates 32 are arranged in the first guide chamber 3, and the first guide plates 31 and the second guide plates are arranged at intervals from top to bottom; the plurality of first guide plates 31 are arranged in a row, and an angle is formed between each first guide plate 31 and the Y direction of the horizontal plane, and the angle between the first guide plates 31 and the horizontal plane from the middle to the two sides changes uniformly, so that the clean high-temperature flue gas can be evenly diffused along the Y direction of the horizontal plane; the plurality of second guide plates 32 are arranged in a row, and an angle is formed between each second guide plate 32 and the X direction of the horizontal plane, and the angle between the second guide plates 31 and the horizontal plane from the middle to the two sides changes uniformly. The angle between the second guide plate 32 and the horizontal plane changes evenly, and finally the clean high-temperature flue gas can be evenly diffused along the X direction of the horizontal plane; through the combination of the first guide plate 31 and the second guide plate 32, the high-temperature flue gas can be evenly diffused from the relatively small outlet pipe 23 to a larger space, which is conducive to the high-temperature flue gas to evenly enter multiple heat exchange tubes 14, thereby facilitating the increase of the number of heat exchange tubes 14 and the heat exchange area of the heat exchange chamber 11 to improve the heat exchange efficiency of the heat exchange chamber 11, and avoid the situation where the flue gas concentrates on entering the heat exchange tubes 14 in some areas. The accumulation of heat, in addition, the heat exchange tubes 14 with a larger coverage area can also fully extend the heat exchange time between the cold air and the heat exchange tubes 14 and increase the heat exchange amount.
[0029] The second guide chamber 4 is arranged between the cold air inlet 12 and the heat exchange chamber 11, and the inner cavity size of the second guide chamber 4 gradually increases from the cold air inlet 12 to the heat exchange chamber 11; a plurality of third guide plates 41 are arranged in the second guide chamber 4, and the plurality of third guide plates 41 are arranged in a row, and an angle is formed between each third guide plate 41 and the Z direction of the vertical plane, and the angle between the third guide plates 41 and the vertical plane from the middle to the two sides changes uniformly; the third guide plates 41 can be used to evenly diffuse the cold air to the vertical plane of the heat exchange chamber 11, thereby increasing the contact area between the cold air and the heat exchange tube 14 and improving the heat exchange efficiency.
[0030] The slow flow chamber 5 is arranged between the hot air outlet 13 and the heat exchange chamber 11, and the inner cavity size of the slow flow chamber 5 gradually decreases from the heat exchange chamber 11 to the hot air outlet 13; a plurality of slow flow plates 51 are arranged in the slow flow chamber 5, and the slow flow plates 51 are folded plates, and the inner angle of the folded plates is toward the side of the heat exchange chamber 11; the slow flow plates 51 can play a role in slowing down the air flow, avoiding the situation where the heat exchange air passes through the heat exchange chamber 11 quickly, thereby prolonging the heat exchange time between the air and the heat exchange tube 14 and increasing the heat exchange amount.
[0031] A heat storage body 6 is provided in the heat exchange tube 14, and the heat storage body 6 is a honeycomb ceramic heat storage body 6. After the dust removal device 2 removes the smoke in the high-temperature flue gas, the impurities contained in the clean high-temperature flue gas are very low, so even if the heat storage body 6 is placed, the heat exchange tube 14 will not be easily blocked. Therefore, after the heat storage body 6 is added to the heat exchange tube 14, heat can be continuously absorbed and released through the heat storage body 6, thereby improving the heat exchange quality and reducing the influence of flue gas temperature fluctuations on air heat exchange; in addition, the use of the honeycomb ceramic heat storage body 6 can utilize its porous thin wall characteristics to greatly increase the geometric surface area and thermal shock resistance of the carrier, and the evenly distributed through holes of the honeycomb ceramic heat storage body 6 will not intercept rare impurities in the clean flue gas, which is beneficial to extend the maintenance and cleaning time of the heat exchange tube 14.
[0032] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. An air preheater, characterized in that: It includes a heat exchange device and a dust removal device; the heat exchange device includes a heat exchange chamber and a cold air inlet and a hot air outlet respectively arranged at both ends of the heat exchange chamber, and a heat exchange pipe is arranged in the heat exchange chamber; the dust removal device is connected to the inlet end of the heat exchange pipe.
2. The air preheater according to claim 1, characterized in that: The dust removal device adopts a cyclone separator, and the dust removal device includes a separation chamber, an air inlet pipe, an air outlet pipe and a dust outlet. The air inlet pipe, the air outlet pipe and the dust outlet are all arranged on the separation chamber, and the air outlet pipe is connected to the inlet end of the heat exchange tube.
3. The air preheater according to claim 2, characterized in that: The air inlet pipe is arranged at the upper part of the side wall of the separation chamber, the air outlet pipe is arranged at the central area of the top wall of the separation chamber, the dust outlet is arranged at the bottom of the separation chamber, and the heat exchange device is arranged above the dust removal device.
4. The air preheater according to claim 1, characterized in that: The air preheater further includes a first flow guide chamber, which is arranged between the dust removal device and the heat exchange tube, and the inner cavity size of the first flow guide chamber gradually increases from the dust removal device to the heat exchange tube.
5. The air preheater according to claim 4, characterized in that: A plurality of first guide plates and a plurality of second guide plates are arranged in the first guide chamber, and the first guide plates and the second guide plates are spaced apart from each other in the upper and lower parts; the plurality of first guide plates are arranged in a row, and an angle is formed between each first guide plate and the Y direction of the horizontal plane, and the angle between the first guide plates in the middle to the two sides and the horizontal plane changes evenly; the plurality of second guide plates are arranged in a row, and an angle is formed between each second guide plate and the X direction of the horizontal plane, and the angle between the second guide plates in the middle to the two sides and the horizontal plane changes evenly.
6. The air preheater according to claim 1, characterized in that: The air preheater further comprises a second flow guide chamber, which is arranged between the cold air inlet and the heat exchange chamber, and the inner cavity size of the second flow guide chamber gradually increases from the cold air inlet to the heat exchange chamber.
7. The air preheater according to claim 6, characterized in that: A plurality of third guide plates are arranged in a row in the second guide chamber, and each third guide plate forms an angle with the Z direction of the vertical plane. The angles between the third guide plates in the middle and the vertical plane change evenly from the middle to the two sides.
8. The air preheater according to claim 1, characterized in that: The air preheater further comprises a slow flow chamber, which is arranged between the hot air outlet and the heat exchange chamber, and the inner cavity size of the slow flow chamber gradually decreases from the heat exchange chamber to the hot air outlet.
9. The air preheater according to claim 8, characterized in that: A plurality of slow flow plates are arranged in the slow flow chamber, and the slow flow plates are folded plates, and the inner angle of the folded plates faces one side of the heat exchange chamber.
10. The air preheater according to claim 1, characterized in that: A heat storage body is arranged in the heat exchange tube, and the heat storage body is a honeycomb ceramic heat storage body.