A flue gas treatment system

Abstract

The application provides a flue gas treatment system, comprising an absorption heat pump, a flue, a heat exchanger and a desulfurization tower arranged in the flue, the heat exchanger being located upstream of the desulfurization tower, the absorption heat pump comprising an evaporator, the heat exchanger being used for absorbing heat of flue gas in the flue to heat medium of the evaporator, the absorption heat pump further comprising a condenser, the condenser being arranged in the flue and located on a downstream side of the desulfurization tower and being used for reheating the flue gas in the flue. The application takes heat from an upstream position of the desulfurization tower to improve overall operation parameters of the absorption heat pump, thereby improving temperature and pressure of condenser steam in the condenser; meanwhile, the condenser and the absorption heat pump are separately arranged and located downstream of the desulfurization tower, the intermediate water circuit and the corresponding heat transfer process thermal resistance are removed, the flue gas temperature can be reheated to 80-90 DEG C, thereby meeting the white smoke elimination requirement of the flue gas, and the white smoke elimination and waste heat utilization of the flue gas are considered.

Description

Technical Field

[0001] This invention relates to the field of flue gas treatment technology, and more specifically, to a flue gas treatment system. Background Technology

[0002] Given the limited availability of natural gas, improving heating efficiency through waste heat recovery technology will become increasingly important. Currently, boiler technology is quite mature, with efficiency reaching 96%, making it difficult to achieve significant energy savings through boiler equipment alone. Considering that the main component of boiler fuel is fossil fuels containing a large amount of hydrogen bonds, the flue gas produced contains 10-17% water vapor, with a condensation temperature of approximately 55-80℃. The latent heat of vaporization of water vapor accounts for about 6-11% of the fuel's lower heating value. However, due to issues such as low air preheating capacity and boiler return water temperature, the flue gas temperature is generally above 60℃, making it impossible to effectively utilize the latent heat of water vapor in the flue gas, resulting in a waste of low-temperature waste heat. Furthermore, after the flue gas exits the chimney, a large amount of water vapor condenses in the air, forming visual "white smoke" pollution. If the water vapor in the flue gas could be condensed, its latent heat could be fully utilized.

[0003] In extreme weather conditions, even after waste heat recovery and descaling, a very small amount of uncondensed water vapor in the flue gas can still form white smoke due to the low air temperature and poor diffusion. Therefore, the discharged flue gas is reheated to raise its temperature, so that the flue gas is far away from its dew point curve and white smoke is avoided near the chimney.

[0004] To eliminate or mitigate the white smoke phenomenon in exhaust gas, heating the gas before it is discharged is a common method, which reduces the relative humidity of the gas to keep it unsaturated. However, existing flue gas reheating devices all have certain shortcomings. For example, (1) if high-temperature (≥120℃) steam / hot water is used as a heat source to reheat the low-temperature flue gas (about 50℃) at the outlet of the desulfurization tower, there is a problem of high-grade heat energy waste; (2) if a gas-to-gas heat exchanger is used to use the high-temperature flue gas (about 150℃) after boiler dust removal as a heat source to reheat the low-temperature flue gas (about 50℃), it is difficult to achieve the function of waste heat recovery; (3) since the temperature of the low-temperature flue gas after the desulfurization tower is 20-50℃, if an absorption heat pump for waste heat recovery is used to extract the heat from the low-temperature waste heat source and use the hot water produced by the heat pump condenser to reheat the low-temperature flue gas, the temperature of the hot water produced by the heat pump condenser is low because the temperature of the low-temperature waste heat source is low, and the temperature of the flue gas after reheating (about 60℃-70℃) is not high, requiring additional reheating equipment; if intermediate water is used as an intermediate medium to heat the low-temperature flue gas at the outlet of the desulfurization tower, the thermal resistance of the heat transfer process is increased, further reducing the achievable flue gas reheating temperature.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The problem solved by this invention is that the existing flue gas treatment devices have an unreasonable structure and it is difficult to simultaneously achieve flue gas whitening and flue gas waste heat utilization.

[0007] To address the aforementioned problems, this invention provides a flue gas treatment system, comprising an absorption heat pump and a flue. A heat exchanger and a desulfurization tower are installed within the flue. The heat exchanger is located upstream of the desulfurization tower. The absorption heat pump includes an evaporator, which absorbs heat from the flue gas within the flue to heat the medium in the evaporator. The absorption heat pump also includes a condenser, which is located within the flue and downstream of the desulfurization tower, and is used to reheat the flue gas within the flue.

[0008] In this application, the heat exchanger extracts heat from upstream of the desulfurization tower, where the flue gas temperature is higher, which helps to improve the overall operating parameters of the absorption heat pump, thereby increasing the temperature and pressure of the refrigerant vapor in the condenser. At the same time, the condenser and the absorption heat pump are separately set and located downstream of the desulfurization tower, eliminating the intermediate water circuit and the corresponding thermal resistance of the heat transfer process, which can reheat the flue gas temperature to 80-90℃, thereby meeting the requirements for flue gas whitening. The working fluid used by the absorption heat pump is LiBr-H2O or NH3-H2O, with a maximum output temperature ≤150℃ and a heating capacity of generally 30-50℃, which can heat the boiler feedwater, thereby achieving the utilization of flue gas waste heat while meeting the requirements for flue gas whitening.

[0009] Preferably, the absorption heat pump further includes an absorber and a generator. The absorber is coupled to the boiler inlet water pipe to achieve heat exchange. The absorber, generator, condenser and evaporator are connected in sequence. The generator heats the medium by driving a heat source to generate medium steam.

[0010] The boiler return water pipeline is heated in the absorber and the feedwater does not enter the condenser. Through the circulation of "refrigerant-solution" inside the absorption heat pump, a portion of the waste heat absorbed by the evaporator can be used to heat the boiler feedwater, achieving the effect of partial waste heat recovery.

[0011] Preferably, the condenser is connected to the generator and evaporator respectively through a medium channel, and the medium channel is equipped with a throttling component. The structure is simple and easy to manufacture.

[0012] Preferably, the condenser is a tube bundle heat exchanger, wherein the inner and outer sides of the tube bundle are supplied with medium steam and flue gas, respectively. Because the refrigerant steam inside the condenser condenses into beads, its heat transfer coefficient is much higher than that of the intermediate water, and therefore its thermal resistance is much lower than that of the intermediate water, further increasing the temperature of the flue gas after reheating.

[0013] Preferably, a cyclone device is installed in the flue, and the cyclone device is located between the condenser and the desulfurization tower to drive the flue gas in the flue to rotate.

[0014] This design causes the flue gas to rotate and rise along the side wall of the flue, thereby effectively reducing the flow velocity of the flue gas in the vertical direction. Compared with traditional flues, the rising height of the flue gas after exiting the flue is reduced, which effectively reduces the condensation of water vapor in the flue gas due to contact with the cold air at a higher position, thereby further ensuring the elimination of white spots in the flue gas.

[0015] Preferably, the cyclone device includes a support frame, on which a wind turbine assembly is mounted, and at least one end of the wind turbine assembly is rotatably connected to the support frame. This configuration is simple in structure and convenient for production and processing.

[0016] Preferably, the bracket includes an upper seat plate and a lower seat plate. The lower seat plate is fixedly connected to the side wall of the flue and is provided with an air passage hole. The upper seat plate is horizontally fixed in the flue and rotatably connected to the impeller assembly. The projected areas of the lower seat plate, the air passage hole, and the flue in the horizontal direction are S1, S2, and S3, respectively, where S1 < S2 < 0.5 * S3.

[0017] This configuration allows the cyclone device to draw in air from the center of the lower base plate, and after the impeller assembly rotates, the air exits from the periphery of the upper base plate, causing the flue gas to spiral upward within the flue. At the same time, it reduces the gas pressure in the middle area of ​​the flue and makes it slightly lower than atmospheric pressure. Simultaneously, the cyclone device can rotate under the action of the airflow, thereby balancing the airflow pressure on both sides of the flue.

[0018] Preferably, the lower base plate gradually tapers towards the rotation axis of the impeller assembly from bottom to top, and the lower base plate is provided with air passage holes, the size of which is the same as the air inlet of the impeller assembly. This arrangement can guide the flue gas entering the cyclone device, resulting in low flow resistance.

[0019] Preferably, the cyclone device further includes an upwardly inclined air intake plate, the outlet end of which is located directly above the upper base plate.

[0020] This setup can guide and comb the rotating flue gas. At the same time, because the air pressure in the middle area of ​​the flue is low, outside air can be drawn into the flue gas through the air inlet plate, which promotes the mixing of the introduced air and the flue gas to be treated, improves the uniformity of mixing or contact, and improves the controllability of flue gas parameters to increase the whitening effect.

[0021] Preferably, the cyclone device further includes a jacket, which is located on the outer periphery of the flue and is not lower than the impeller assembly. The inlet end of the jacket is connected to the boiler inlet water pipe, and the outlet end of the jacket is connected to the absorber.

[0022] This setup can preheat the boiler inlet water pipe using the flue, and then heat the boiler inlet water pipe through the absorber, resulting in high waste heat utilization. At the same time, the boiler inlet water pipe is used to cool the flue gas. The cooled flue gas collides with the side wall of the flue as it rotates and rises, and condenses water when it mixes with air, thereby further reducing the water vapor content in the flue gas. With the combined effect of air dilution and condenser reheating, the flue gas whitening effect is excellent.

[0023] Compared with the prior art, the flue gas treatment system of the present invention has the following beneficial effects:

[0024] 1) The evaporator extracts heat from the higher-temperature flue gas before the desulfurization tower. This helps improve the overall operating parameters of the heat pump, thereby increasing the temperature and pressure of the refrigerant vapor in condenser 4, and further increasing the reheated flue gas temperature to 80-90℃;

[0025] 2) The boiler feedwater is heated in the absorber and does not enter the condenser. Through the circulation of "refrigerant-solution" inside the absorption heat pump, a portion of the waste heat absorbed by the evaporator can be used to heat the boiler feedwater, thus achieving the effect of partial waste heat recovery.

[0026] 3) The condenser is separated from the absorption heat pump and is located downstream of the desulfurization tower to heat the low-temperature flue gas. This eliminates the intermediate water circuit and the corresponding heat transfer process thermal resistance, thereby increasing the achievable temperature of the flue gas after reheating. When the refrigerant vapor inside the condenser condenses, it is in bead form, and the heat transfer coefficient is much higher than that of the intermediate water. Therefore, the heat transfer thermal resistance is much lower than that of the intermediate water, further increasing the achievable temperature of the flue gas after reheating. Attached Figure Description

[0027] Figure 1 This is an overall schematic diagram of the flue gas treatment system described in Embodiment 1 of the present invention;

[0028] Figure 2 This is a schematic diagram of the flue gas treatment system described in Embodiment 2 of the present invention.

[0029] Figure 3 This is a schematic diagram of the cyclone device described in Embodiment 2 of the present invention;

[0030] Figure 4 This is a schematic diagram of the wind turbine assembly described in Embodiment 2 of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1-Absorption heat pump; 11-Absorber; 12-Evaporator; 13-Generator; 14-Condenser; 141-Medium passage; 142-Throttling component; 15-Heat exchanger; 2-Flue; 3-Boiler inlet pipe; 4-Boiler return pipe; 5-Desulfurization tower; 6-Cyclone device; 61-Wind impeller assembly; 611-Hub; 612-Base plate; 613-Guide ring; 614-Iron blade; 6141-Gear; 6142-Notch; 615-Shaft sleeve; 62-Bracket; 621-Upper seat plate; 622-Lower seat plate; 63-Jacket; 64-Inlet plate. Detailed Implementation

[0033] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the technical features in the various embodiments of the present invention can be combined with each other without conflict.

[0034] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] Flue gas heat loss accounts for the largest proportion of boiler heat loss, approximately 6-11%. Therefore, flue gas waste heat is an important component of waste heat resources. Fully recovering and utilizing waste heat resources in flue gas not only has significant economic and social benefits but also helps improve energy efficiency, aligning with societal requirements for energy conservation and emission reduction. While existing flue gas reheat devices achieve some degree of "white spot elimination," they cannot simultaneously address both flue gas waste heat recovery and white spot elimination, and suffer from drawbacks such as high cost and complex structure.

[0036] Therefore, the applicant proposes the following technical solution:

[0037] Example 1

[0038] like Figure 1 As shown, a flue gas treatment system includes an absorption heat pump 1 and a flue 2. A heat exchanger 15 and a desulfurization tower 5 are installed in the flue 2. The heat exchanger 15 is located upstream of the desulfurization tower 5. The absorption heat pump 1 includes an evaporator 12. The heat exchanger 15 is used to absorb heat from the flue gas in the flue 2 to heat the medium in the evaporator 12. The absorption heat pump 1 also includes a condenser 14. The condenser 14 is installed in the flue 2 and located downstream of the desulfurization tower 5, and is used to reheat the flue gas in the flue 2.

[0039] In this application, heat exchanger 15 extracts heat from upstream of desulfurization tower 5, where the flue gas temperature is higher, which helps to improve the overall operating parameters of absorption heat pump 1, thereby increasing the temperature and pressure of refrigerant vapor in condenser 14. At the same time, condenser 14 is separately set from absorption heat pump 1 and is located downstream of desulfurization tower 5, eliminating the intermediate water circuit and the corresponding thermal resistance of heat transfer process, which can reheat the flue gas temperature to 80-90℃, thereby meeting the requirements for flue gas whitening. The working fluid used by absorption heat pump 1 is LiBr-H2O or NH3-H2O, with a maximum output temperature ≤150℃ and a heating capacity of generally 30-50℃, which can heat boiler feedwater, thereby achieving the utilization of flue gas waste heat while meeting the requirements for flue gas whitening.

[0040] Preferably, the absorption heat pump 1 further includes an absorber 11 and a generator 13. The absorber 11 is coupled to the boiler inlet pipe 3 and the boiler return pipe 4 respectively to achieve heat exchange. The absorber 11, generator 13, condenser 14 and evaporator 12 are connected in sequence. The generator 13 is heated by driving a heat source to generate medium steam.

[0041] The boiler return water pipeline 4 is heated in the absorber 11 and the feed water does not enter the condenser 14. Through the circulation of "refrigerant-solution" inside the absorption heat pump 1, a portion of the waste heat absorbed by the evaporator 12 can be used to heat the boiler feed water, thus achieving the effect of partial waste heat recovery.

[0042] Preferably, the condenser 14 is a tube bundle heat exchanger, wherein the inner and outer sides of the tube bundle are respectively supplied with medium steam and flue gas. Because the refrigerant steam inside the condenser 14 condenses into beads, its heat transfer coefficient is much higher than that of the intermediate water, so its thermal resistance is much lower than that of the intermediate water, which further increases the temperature of the flue gas after reheating.

[0043] Preferably, the condenser 14 is connected to the generator 13 and the evaporator 12 respectively through a medium channel 141, and the medium channel 141 is provided with a throttling component 142.

[0044] During operation, heat exchanger 15 absorbs heat from the high-temperature (approximately 120-150℃) flue gas and transfers it to evaporator 12. The flue gas then passes through desulfurization tower 5 for desulfurization and is directly heated by condenser 14 to raise its temperature to 80-90℃, thus solving the problem of flue gas whitening. For absorption heat pump 1, generator 13 drives a heat source to generate high-temperature, high-pressure medium vapor, which enters condenser 14 located in flue 2 through medium channel 141 for direct heat exchange heating of the flue gas (approximately 50℃) treated by desulfurization tower 5. The medium that releases heat in condenser 14 passes through throttling component 142 and enters evaporator 12 for evaporation, continuously utilizing heat exchanger 15 to recover heat from the flue gas. Absorber 11 absorbs the medium vapor generated by evaporator 12, completing the "solution-refrigerant" cycle while simultaneously heating the water in boiler inlet pipe 3 and then transporting it to the boiler through boiler return pipe 4, achieving waste heat recovery.

[0045] Example 2

[0046] To further improve the whitening effect of flue 2, the applicant made the following improvements based on Example 1:

[0047] like Figure 2-4 As shown, a flue gas treatment system includes an absorption heat pump 1 and a flue 2. A heat exchanger 15 and a desulfurization tower 5 are installed in the flue 2. The heat exchanger 15 is located upstream of the desulfurization tower 5. The absorption heat pump 1 includes an evaporator 12. The heat exchanger 15 is used to absorb heat from the flue gas in the flue 2 to heat the medium in the evaporator 12. The absorption heat pump 1 also includes a condenser 14. The condenser 14 is arranged on the central axis of the flue 2 and has a gap with the side wall of the flue 2. It is located downstream of the desulfurization tower 5 and is used to reheat the flue gas in the flue 2.

[0048] This application extracts heat from the upstream location of the desulfurization tower 5, where the flue gas temperature is higher, which helps to improve the overall operating parameters of the absorption heat pump 1, thereby increasing the temperature and pressure of the refrigerant vapor in the condenser 14. At the same time, the condenser 14 is separately set from the absorption heat pump 1 and is located downstream of the desulfurization tower 5, eliminating the intermediate water circuit and the corresponding thermal resistance of the heat transfer process. This allows the flue gas temperature to be reheated to 80-90℃ without interfering with the flow of the flue gas, especially the spiral ascent. This achieves the utilization of the waste heat of the flue gas while satisfying the elimination of whitening of the flue gas.

[0049] A cyclone device 6 is installed inside the flue 2, located between the condenser 14 and the desulfurization tower 5, to drive the flue gas inside the flue 2 to rotate. This arrangement causes the flue gas to rotate and rise along the side wall of the flue 2, thereby effectively reducing the vertical flow velocity of the flue gas. Compared to a traditional flue 2, the rising height of the flue gas after exiting the flue 2 is reduced, effectively reducing the contact between water vapor in the flue gas and the cold air at a higher position, thus reducing condensation. Although the temperature of the flue gas is reduced after reheating by the condenser 14, the overall flue gas whitening effect is better.

[0050] Preferably, the cyclone device 6 is located at the outlet end of the flue 2, and the cyclone device 6 and the desulfurization tower 5 are located on both sides of the condenser 14. This arrangement can prevent the condenser 14 from interfering with the rotation of the flue gas, allowing the flue gas to spiral upward within the flue 2.

[0051] As an example of the present invention, the cyclone device 6 includes a wind turbine assembly 61, which includes a hub 611, a base plate 612, and a guide ring 613. The lower edge of the hub 611 extends to form the base plate 612, and a fan blade 614 is disposed on the base plate 612. The fan blade 614 is inserted into the base plate 612, and the upper end of the fan blade 614 is inserted into the guide ring 613. A portion of the guide ring 613 extends out of the lower base plate 622. When flue gas enters through the air inlet of the guide ring 613 and finally exits from the outer periphery of the wind turbine assembly 61, the fan blades 614 are arranged in a circular array along the periphery of the base plate 612. Due to the guiding effect of the fan blades 614, the flue gas flow can spiral upward along the side wall of the flue 2.

[0052] The projection of the hub 611 onto the horizontal plane gradually increases from one end near the lower seat plate 622 toward the side of the base plate 612. This arrangement guides the flue gas entering the impeller assembly 61, preventing airflow turbulence inside the impeller assembly 61.

[0053] An air outlet is formed between the base plate 612, the guide ring 613, and the fan blade 614. As a preferred example of this application, the base plate 612 is provided with fan blade slots for mounting and fixing the fan blade 614; the fan blade slots are evenly distributed along the periphery of the base plate 612. Preferably, both ends of the fan blade 614 are respectively snap-fitted into the base plate 612 and the guide ring 613. This configuration allows for the detachable construction of the fan blade 614, base plate 612, and guide ring 613, facilitating the maintenance and assembly of the impeller assembly 61; of course, the fan blade 614 can also be fixed to the base plate 612 and the guide ring 613 by adhesive bonding to ensure a secure assembly.

[0054] As a preferred embodiment of the present invention, the fan blade 614 is provided with a retaining tooth 6141 and a notch 6142 near the air outlet, with the notch 6142 located below the retaining tooth 6141. This arrangement can stabilize the airflow at the air outlet and reduce the noise of the flue gas flow. Preferably, a bushing 615 is provided on the top of the hub 611, and the bushing 615 is used for rotatable connection with the bracket 62.

[0055] As a preferred example of the present invention, the cyclone device 6 includes a support 62, on which a wind turbine assembly 61 is mounted, and at least one end of the wind turbine assembly 61 is rotatably connected to the support 62. This configuration has a simple structure and is easy to manufacture.

[0056] As an example of the present invention, the bracket 62 includes an upper base plate 621 and a lower base plate 622. The lower base plate 622 is fixedly connected to the side wall of the flue 2. The lower base plate 622 is provided with an air passage hole. The upper base plate 621 is horizontally fixed in the flue 2 and rotatably connected to the impeller assembly 61. The projected areas of the lower base plate 622, the air passage hole, and the flue 2 in the horizontal direction are S1, S2, and S3, respectively, where S1 < S2 < 0.5 * S3.

[0057] This configuration allows the cyclone device 6 to take in air from the middle of the lower base plate 622, and after the impeller assembly 61 rotates, the air exits from the periphery of the upper base plate 621, causing the flue gas to spiral upward in the flue 2. At the same time, it reduces the gas pressure in the middle area of ​​the flue 2 and makes it slightly lower than atmospheric pressure. Meanwhile, the cyclone device 6 can rotate under the action of the airflow, thereby balancing the airflow pressure on both sides of the flue 2.

[0058] A first support rod is provided on the periphery of the upper base plate 621, and the first support rod is fixedly connected to the flue 2; a second support rod is provided on the inner periphery of the lower base plate 622, and a bearing is provided on the second support rod for rotatable connection with the impeller assembly 61. This arrangement ensures that all flue gas spirals upward after passing through the impeller assembly 61, while supporting both sides of the impeller assembly 61, resulting in low vibration during operation of the impeller assembly 61, thereby further reducing the gap between the impeller assembly 61 and the lower base plate 622.

[0059] Preferably, the lower base plate 622 is arranged in a circular or trumpet shape. Preferably, the lower base plate 622 gradually tapers towards the rotation axis of the impeller assembly 61 from bottom to top, and the lower base plate 622 is provided with air passage holes, the size of which is the same as the air inlet hole of the impeller assembly 61. This arrangement can guide the flue gas entering the cyclone device 6, resulting in low flow resistance.

[0060] Preferably, the cyclone device 6 further includes an upwardly inclined air inlet plate 64, the outlet end of which is located directly above the upper base plate 621. This arrangement can guide and comb the rotating flue gas. Simultaneously, due to the low air pressure in the middle region of the flue 2, outside air can be drawn into the flue 2 by the rotating flue gas through the air inlet plate 64, promoting the mixing of the introduced air and the flue gas to be treated, improving the uniformity of mixing or contact, and enhancing the controllability of flue gas parameters to increase the whitening effect.

[0061] Preferably, there are multiple air intake plates 64 arranged at different heights in the flue 2, and the projection of the air intake plates 64 on the horizontal plane is distributed in a circular array along the circle containing the flue 2. This arrangement has a simple structure and can automatically adjust the air intake ratio according to the airflow and rotation speed of the flue gas. When the flue gas rotation speed is higher, the air pressure at the center of the flue 2 is lower. At this time, the proportion of air drawn in through the air intake plates 64 is larger, but the rising distance of the flue gas after exiting the flue 2 is shorter, resulting in a better whitening effect. Conversely, when the flue gas rotation speed is lower, the air pressure at the center of the flue 2 is higher. At this time, the proportion of air drawn in through the air intake plates 64 is smaller, thus meeting the whitening requirements under different weather conditions.

[0062] Preferably, the bracket 62 is equipped with a drive device, which is connected to the impeller assembly 61. This configuration allows control of the rotational speed of the impeller assembly 61, thereby controlling the proportion of introduced air, improving the controllability of flue gas parameters, and enhancing the whitening effect.

[0063] As an example of the present invention, the cyclone device 6 further includes a jacket 63, which is located on the outer periphery of the flue 2 and is not lower than the impeller assembly 61. The inlet end of the jacket 63 is connected to the boiler inlet pipe 3, and the outlet end of the jacket 63 is connected to the absorber 11. This arrangement can preheat the boiler inlet pipe 3 using the flue 2, and then heat the boiler inlet pipe 3 through the absorber 11, resulting in high waste heat utilization. At the same time, the flue gas is cooled by the boiler inlet pipe 3. The cooled flue gas collides with the side wall of the flue 2 as it rotates and rises, and condenses water when it mixes with air, thereby further reducing the water vapor content in the flue gas. In addition, the combined effect of dilution by air and reheating by the condenser 14 further improves the whitening effect of the flue gas.

[0064] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A flue gas treatment system, characterized in that, The system includes an absorption heat pump (1) and a flue (2). A heat exchanger (15) and a desulfurization tower (5) are installed in the flue (2). The heat exchanger (15) is located upstream of the desulfurization tower (5). The absorption heat pump (1) includes an evaporator (12). The heat exchanger (15) is used to absorb the heat of the flue gas in the flue (2) to heat the medium in the evaporator (12). The absorption heat pump (1) also includes a condenser (14). The condenser (14) is installed in the flue (2) and located downstream of the desulfurization tower (5) to reheat the flue gas in the flue (2). A cyclone device (6) is installed inside the flue (2). The cyclone device (6) is located between the condenser (14) and the desulfurization tower (5) and is used to drive the flue gas in the flue (2) to rotate. The cyclone device (6) includes a support (62). The support (62) is provided with a wind turbine assembly (61). At least one end of the wind turbine assembly (61) is rotatably connected to the support (62). The support (62) includes an upper seat plate (621) and a lower seat plate (622). The lower seat plate (622) is fixedly connected to the side wall of the flue (2). The lower seat plate (622) is provided with an air passage hole. The upper seat plate (621) is horizontally fixed inside the flue (2) and rotatably connected to the wind turbine assembly (61). The projected areas of the lower seat plate (622), the air passage hole, and the flue (2) in the horizontal direction are S1, S2, and S3, respectively, where S1 < S2 < 0.5 * S3.

2. The flue gas treatment system according to claim 1, characterized in that, The absorption heat pump (1) also includes an absorber (11) and a generator (13). The absorber (11) is coupled to the boiler inlet pipe (3) to achieve heat exchange. The absorber (11), generator (13), condenser (14) and evaporator (12) are connected in sequence. The generator (13) generates medium steam by driving a heat source to heat the medium.

3. The flue gas treatment system according to claim 2, characterized in that, The condenser (14) is connected to the generator (13) and the evaporator (12) respectively through a medium channel (141), and the medium channel (141) is provided with a throttling component (142).

4. The flue gas treatment system according to claim 3, characterized in that, The condenser (14) is a tube bundle heat exchange device, wherein the inner and outer sides of the tube bundle are respectively supplied with medium steam and flue gas flow.

5. The flue gas treatment system according to claim 1, characterized in that, The lower base plate (622) gradually contracts towards the rotation axis of the wind turbine assembly (61) from bottom to top. The lower base plate (622) is provided with air passage holes, and the size of the air passage holes is the same as that of the air inlet of the wind turbine assembly (61).

6. The flue gas treatment system according to claim 5, characterized in that, The cyclone device (6) also includes an upwardly inclined air intake plate (63), the outlet end of which is located directly above the upper seat plate (621).

7. The flue gas treatment system according to claim 2, characterized in that, The cyclone device (6) also includes a jacket (64), which is located on the outer periphery of the flue (2) and is not lower than the impeller assembly (61). The inlet end of the jacket (64) is connected to the boiler water inlet pipe (3), and the outlet end of the jacket (64) is connected to the absorber (11).

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