Device for recovering moisture in desulfurized flue gas of coal-fired power plant

Abstract

According to the device for recovering the moisture in the desulfurized flue gas of the coal-fired power plant, the desulfurized flue gas 201 flows through the device 101 for recovering the moisture in the desulfurized flue gas of the power plant from bottom to top, and in the process, pollutants such as tiny liquid drops 202 and dust particles 203 in the flue gas 201 are captured by the device 101 for recovering the moisture in the desulfurized flue gas of the power plant and condensed and recovered. Compared with a tube bundle recoverer used by a desulfurization device of a coal-fired power plant at present, the distance from particles to the surface of a tube wall is shorter, the particles are captured by the tube wall more easily, resistance is small, emission is less, cleaning is easy, occupied space is small, cost is low, moisture in flue gas obtained after desulfurization of the power plant can be efficiently recovered, and meanwhile particle emission is greatly reduced.

Description

Technical Field

[0001] The invention relates to the field of flue gas treatment for thermal power generation, and in particular to a device for recovering water from desulfurized flue gas in a coal-fired power plant. Background Art

[0002] As a major consumer of water and energy, coal-fired power plants have become the focus of energy conservation and emission reduction due to their huge water and energy consumption. my country's power development plan for 2005-2020 clearly puts forward the issue of water conservation in power generation, and efforts must be made to develop water-saving flue gas pollution control technologies suitable for areas with water shortages.

[0003] The cost of industrial water use has gradually increased. In 2012, the country revised the water quota standards and reduced the water quota for thermal power generation by more than 30% from the 2002 level. In April 2015, my country issued the "Action Plan for Water Pollution Prevention and Control", which proposed strict water pollution prevention and control targets. Coal-fired power plants are facing tremendous pressure to save water and reduce emissions. Most of my country's newly built coal-fired units are located in the western coal-producing and water-scarce areas, and there is an urgent need to save water and reduce consumption.

[0004] The flue gas produced after desulfurization in coal-fired power plants has the characteristics of high humidity, easy agglomeration, and high dust concentration. It is easy to cause chimney corrosion after emission. The saturated wet flue gas is directly discharged into the atmosphere and condenses into water droplets when it gets cold, forming "white smoke" under the refraction of sunlight, causing visual pollution.

[0005] Reducing the emission of water vapor and waste heat after desulfurization in coal-fired power plants is one of the key directions for water conservation and consumption reduction in coal-fired power plants. Due to the coupling effect of moisture and latent heat in flue gas, effective flue gas dehumidification technology can simultaneously recover moisture and latent heat, reduce water consumption and particulate matter emissions in power plants, and fundamentally solve the chimney corrosion and "white smoke" phenomenon.

[0006] Flat-plate demisters are often used to remove large droplets. Their technical features include the use of baffle flow channels, simple structure, and pressure drop of less than 200 Pa. Flat-plate demisters have a low removal rate for particles of 10 microns and below. Ridge-type demisters are an improvement on the layout of flat-plate demisters, and there is no major difference in the working principle.

[0007] The working principle of the tube bundle demister is that the flue gas generates centrifugal motion through the cyclone, and the mist droplets and dust move toward the wall of the tube body, collide and condense and are thrown toward the inner tube wall, flow down in the form of a water film, and fall into the slurry pool to achieve the removal of mist droplets and dust. The inner diameter of the tube bundle demister used in coal-fired power plants is 300 to 600 mm.

[0008] The tube bundle demister and flat plate demister currently used in coal-fired power plants can recover water vapor droplets and particulate dust particles >10 microns in the desulfurized flue gas, but the recovery effect is not ideal for water vapor droplets and particulate dust particles ≤10 microns. New devices are needed to recover these water vapor droplets and particulate dust particles ≤10 microns.

[0009] The Chinese invention patent with the application number CN202311473258.9 proposes a method for improving the purification effect of a microtube bundle demister. By taking advantage of the fact that the space occupied by the microtube bundle demister is much smaller than that of other demisters, the microtube bundle demister is combined with a heat pump, reducing the comprehensive technical transformation cost and the implementation difficulty. Our patent proposes to assemble the microtube bundle demister inside the moisture recovery device, which is directly connected to the flue gas outlet of the power plant, significantly reducing the transformation cost.

[0010] The application technology of combining the microtube bundle demister with a heat pump proposed in the Chinese invention patent with the application number CN202311473258.9 significantly improves the purification effect of the microtube bundle demister and solves the common "gypsum rain" problem in existing thermal power plants. Our patent fundamentally solves the chimney corrosion and "white smoke" phenomena through the moisture recovery device.

[0011] The flue gas cooling tube group at the inlet of the microtube bundle demister proposed in the application number CN202311473258.9 will generate a large amount of condensed water during operation, and its use for the heat pump evaporator tube group and the microtube bundle demister has low cleaning efficiency. The moisture recovery device proposed in our patent can achieve the efficient recovery and utilization of moisture in the desulfurized flue gas of coal-fired power plants. Summary of the Invention

[0012] In order to improve the recovery efficiency of water vapor droplets and particulate dust particles with a size of ≤10 microns in the desulfurized flue gas of coal-fired power plants, the present invention proposes a device for recovering moisture in the desulfurized flue gas of coal-fired power plants. It includes a recovery device with an internal spiral structure and a method for recovering moisture in the desulfurized flue gas of coal-fired power plants using this internal spiral structure recovery device.

[0013] A device for recovering moisture in the desulfurized flue gas of a power plant, characterized in that:

[0014] The moisture recovery device 101 in the desulfurized flue gas of a power plant is composed of one or more recovery modules 102 combined.

[0015] Each recovery module 102 is composed of one or more separation tubes 103 with an internal spiral structure.

[0016] Each separation tube 103 with an internal spiral structure is composed of a hollow separation tube body 104 and a guide spiral 105 located inside the separation tube body 104.

[0017] The flue gas flows through the moisture recovery device 101 in the desulfurized flue gas of a power plant from bottom to top, and the liquid droplets after moisture recovery flow from top to bottom through the moisture recovery device 101 in the desulfurized flue gas of a power plant.

[0018] The moisture recovery device 101 for flue gas after desulfurization in a power plant can be arranged in one layer or multiple layers. Preferably, it is arranged in one layer.

[0019] The moisture recovery device 101 for flue gas after desulfurization in a power plant can be arranged at the top layer inside the existing desulfurization tower of a coal-fired power plant, or a new recovery tower can be built and arranged separately. Preferably, it is arranged at the top layer inside the existing desulfurization tower.

[0020] The body 104 of the separation tube and the guiding spiral 105 are made of the same plastic material. Preferably, it is flame-retardant polypropylene.

[0021] The length of the separation tube 103 with an internal spiral structure is between 0.1 meter and 0.6 meter. Preferably, it is 0.2 meter.

[0022] The inner diameter of the body 104 of the separation tube is the same as or slightly smaller than the outer diameter of the guiding spiral 105. Preferably, the inner diameter of the body 104 of the separation tube is slightly smaller than the outer diameter of the guiding spiral 105.

[0023] The inner diameter of the body 104 of the separation tube is between 10 millimeters and 100 millimeters, with a negative tolerance of 0.1 millimeter. Preferably, it is 10 millimeters - 0.1 millimeter.

[0024] The outer diameter of the guiding spiral 105 is between 10 millimeters and 100 millimeters. The outer diameter of the guiding spiral 105 is the same as the inner diameter of the body 104 of the separation tube, with a positive tolerance of 0.1 millimeter. Preferably, the outer diameter of the guiding spiral 105 is 10 millimeters + 0.1 millimeter.

[0025] The pitch of the guiding spiral 105 is between 10 millimeters and 100 millimeters. Preferably, the pitch of the guiding spiral 105 is 10 millimeters.

[0026] The guiding spiral 105 can be integrally formed with the body 104 of the separation tube, or the guiding spiral 105 and the body 104 of the separation tube can be processed separately and then combined into the separation tube 103 with an internal spiral structure. Preferably, the guiding spiral 105 and the body 104 of the separation tube are processed separately and then combined into the separation tube 103 with an internal spiral structure.

[0027] Each recovery module 102 is composed of a number of separation tubes 103 with an internal spiral structure. The processing method for a single recovery module 102 is as follows: Method a. The body 104 of the separation tube monomer and the diversion spiral 105 monomer are processed separately by the injection molding method. Then, the diversion spiral 105 monomer is inserted into the body 104 of the separation tube monomer to form a separation tube 103 monomer with an internal spiral structure. Subsequently, a number of separation tubes 103 monomers with an internal spiral structure are combined to form the recovery module 102. Method b. The pre-assembly module 106 composed of a number of body 104 monomers of the separation tube and the diversion spiral 105 monomer are processed separately by the injection molding method. Then, the diversion spiral 105 monomer is inserted into the pre-assembly module 106 respectively to form the recovery module 102. Preferably, Method b is adopted.

[0028] The assembly method of the diversion spiral 105 is as follows: Method aa. At room temperature, the diversion spiral 105 monomer is inserted into the body 104 of the separation tube monomer or the pre-assembly module 106 to form a separation tube 103 monomer with an internal spiral structure or the recovery module 102. Method ab. First, the body 104 of the separation tube monomer or the pre-assembly module 106 is heated, and then the room-temperature diversion spiral 105 is inserted. After cooling, a separation tube 103 monomer with an internal spiral structure or the recovery module 102 is formed. Preferably, Method ab is adopted.

[0029] In the assembly method ab of the diversion spiral 105, the heating temperature of the body 104 of the separation tube monomer or the pre-assembly module 106 is 80 - 100 °C, preferably 95 °C.

[0030] The present invention provides a device for recovering moisture in the flue gas after desulfurization in a power plant. The working principle is as follows: The flue gas 201 after desulfurization in the power plant flows upward through the device 101 for recovering moisture in the flue gas after desulfurization in the power plant. The device 101 for recovering moisture in the flue gas after desulfurization in the power plant is composed of a number of separation tubes 103 with an internal spiral structure. The separation tube 103 with an internal spiral structure is composed of an internally hollow body 104 of the separation tube and a diversion spiral 105. The flue gas 201 generates a rotational motion under the guidance of the diversion spiral 105. The centrifugal force generated by the rotation causes the tiny droplets 202 and dust particles 203 in the flue gas 201 to move towards the inner wall of the body 104 of the separation tube 103 with an internal spiral structure. When they touch the tube wall, they are absorbed by the liquid film 204 on the tube wall. Finally, under the action of gravity, the liquid film 204 moves downward and drips into the recovery water tank 107 in the form of large droplets. The tiny droplets 202 in the flue gas 201 are recovered, and the dust particles 203 in the flue gas 201 are purified. The present invention greatly recovers the water in the flue gas 201 after desulfurization in the power plant, and at the same time reduces the particulate matter emission concentration in the flue gas 201, effectively achieving the purposes of water conservation and environmental protection, and providing a good solution for building an environment-friendly and resource-saving society in China.

[0031] A device for recovering moisture in flue gas after desulfurization in a power plant, characterized by including the following steps:

[0032] 1. The flue gas 201 after desulfurization in the power plant flows upward through the moisture recovery device 101 for flue gas after desulfurization in the power plant. During this process, pollutants such as tiny droplets 202 and dust particles 203 in the flue gas 201 are captured and condensed for recovery by the moisture recovery device 101 for flue gas after desulfurization in the power plant.

[0033] 2. The moisture recovery device 101 for flue gas after desulfurization in the power plant is composed of numerous separation tubes 103 with an internal spiral structure. The separation tube 103 with an internal spiral structure is composed of an internal hollow separation tube body 104 and a guide spiral 105. The flue gas 201 generates a rotational motion under the guidance of the guide spiral 105.

[0034] 3. The centrifugal force generated by the rotation causes the tiny droplets 202 and dust particles 203 in the flue gas 201 to move towards the tube wall of the separation tube body 104 of the separation tube 103 with an internal spiral structure and are absorbed by the liquid film 204 on the tube wall when they hit the tube wall.

[0035] 4. Under the action of gravity, the liquid film 204 moves downward and drips into the recovery water tank 107 in the form of large droplets.

[0036] Advantages of the present invention: A device for recovering moisture in desulfurized flue gas of a coal-fired power plant provided by the present invention. The desulfurized flue gas 201 flows upward through the moisture recovery device 101 for flue gas after desulfurization in the power plant. During this process, pollutants such as tiny droplets 202 and dust particles 203 in the flue gas 201 are captured and condensed for recovery by the moisture recovery device 101 for flue gas after desulfurization in the power plant. Compared with the current bundle recovery device used in desulfurization devices of coal-fired power plants, the distance for the particulate matter to move to the tube wall surface is shorter in this method, and it is easier to be captured by the tube wall. Moreover, it has small resistance, less emissions, is easy to clean, occupies less space, and has low costs. It can efficiently recover the moisture in the flue gas after desulfurization in the power plant, and at the same time, significantly reduce the particulate matter emissions.

[0037] Compared with the existing devices for recovering water from flue gas after desulfurization in power plants, the present invention has the following advantages:

[0038] Compared with a common bundle recovery device, the device for recovering moisture in desulfurized flue gas of a coal-fired power plant provided by the present invention is significantly reduced in terms of the diameter of the separation tube, radial distance, volume, and weight.

[0039] Compared with common three-stage baffle recovery devices and 3 - 4 stage bundle recovery devices, the device for recovering moisture in desulfurized flue gas of a coal-fired power plant provided by the present invention has the advantages of high water recovery efficiency, small gas flow resistance (low energy consumption), small flushing difficulty, small occupied space, and low comprehensive cost.

[0040] The device for recovering moisture in desulfurized flue gas of coal-fired power plants provided by the present invention has high separation efficiency. Usually, the particulate matter concentration at the outlet of the primary device is only half of that of the four-stage ordinary tube bundle recovery device, and usually does not require multi-stage series connection.

[0041] Compared with the ordinary tube bundle recovery device, for the device for recovering moisture in desulfurized flue gas of coal-fired power plants provided by the present invention, the distance for fine particles to move to the tube wall surface is short, and it is easier to be captured by the tube wall.

[0042] The device for recovering moisture in desulfurized flue gas of coal-fired power plants provided by the present invention has a funnel aggregation effect. Dust particles are easily carried away by water flow and are not easy to aggregate, reducing particulate matter emissions in the flue gas while recovering water. BRIEF DESCRIPTION OF THE DRAWINGS The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0043] Figure 1 , a composition diagram of a device for recovering moisture in flue gas after desulfurization in a power plant

[0044] Figure 1 Description: The present invention proposes a device for recovering moisture in flue gas after desulfurization in a power plant, and the specific composition is as follows: The separation tube body 104 with a hollow interior and the guide spiral 105 located inside the separation tube body 104 constitute the separation tube 103 with an inner spiral structure. The recovery module 102 is composed of one or more separation tubes 103 with an inner spiral structure, and the device 101 for recovering moisture in flue gas after desulfurization in a power plant is composed of one or more recovery modules 102 combined.

[0045] Figure 1 Legend description: 101. Device for recovering moisture in flue gas after desulfurization in a power plant 102. Recovery module 103. Separation tube with an inner spiral structure 104. Separation tube body 105. Guide spiral

[0046] Figure 2 , a one-time forming processing drawing of a separation tube with an inner spiral structure

[0047] Figure 2 Description: The guide spiral 105 and the separation tube body 104 are processed by a one-time forming method.

[0048] Figure 2 Legend description: 104. Separation tube body 105. Guide spiral

[0049] Figure 3 , the separation tube with an internal spiral structure is processed separately for Figure

[0050] Figure 3 Note: The diversion spiral 105 and the body 104 of the separation tube are processed separately and then combined to form the separation tube 103 with an internal spiral structure.

[0051] Figure 3 Legend: 103. Separation tube with an internal spiral structure 104. Body of the separation tube 105. Diversion spiral

[0052] Figure 4 , Diagram a of the processing method for a single recovery module

[0053] Figure 4 Note: The body 104 monomers of the separation tube and the 105 monomers of the diversion spiral are processed separately by the injection molding method using a mold, and then the 105 monomers of the diversion spiral are inserted into the 104 monomers of the separation tube body to form the 103 monomers of the separation tube with an internal spiral structure. Then, a number of the 103 monomers of the separation tube with an internal spiral structure are combined to form the recovery module 102.

[0054] Figure 4 Legend: 102. Recovery module 103. Separation tube with an internal spiral structure 104. Body of the separation tube 105. Diversion spiral

[0055] Figure 5 , Diagram b of the processing method for a single recovery module

[0056] Figure 5 Note: The pre-assembly module 106 composed of a number of the 104 monomers of the separation tube body and the 105 monomers of the diversion spiral are processed separately by the injection molding method using a mold, and then the 105 monomers of the diversion spiral are inserted into the pre-assembly module 106 respectively to form the recovery module 102.

[0057] Figure 5 Legend: 102. Recovery module 104. Body of the separation tube 105. Diversion spiral 106. Pre-assembly module

[0058] Figure 6 , Diagram aa of the assembly method of the diversion spiral 105

[0059] Figure 6Description: At room temperature, insert the single-piece flow guide spiral 105 into the single-piece separation tube body 104 or the pre-assembled module 106 to form the single-piece separation tube 103 or the recovery module 102 with an internal spiral structure.

[0060] Figure 6 Legend: 103. Separation tube with an internal spiral structure 104. Separation tube body 105. Flow guide spiral

[0061] Figure 7 , Assembly method ab diagram of the flow guide spiral 105

[0062] Figure 7 Description: First, heat the single-piece separation tube body 104 or the pre-assembled module 106, then insert the room-temperature flow guide spiral 105, and after cooling, form the single-piece separation tube 103 or the recovery module 102 with an internal spiral structure.

[0063] Figure 7 Legend: 102. Recovery module 104. Separation tube body 105. Flow guide spiral 106. Pre-assembled module

[0064] Figure 8 It is the recovery principle diagram of the moisture recovery device for the flue gas after desulfurization in a coal-fired power plant.

[0065] Figure 8 Description: The flue gas 201 after desulfurization in the power plant flows upward through the moisture recovery device 101 for the flue gas after desulfurization in the power plant. The moisture recovery device 101 for the flue gas after desulfurization in the power plant is composed of numerous separation tubes 103 with an internal spiral structure. The separation tube 103 with an internal spiral structure is composed of an internally hollow separation tube body 104 and a flow guide spiral 105. The flue gas 201 generates a rotational motion under the guidance of the flow guide spiral 105. The centrifugal force generated by the rotation causes the tiny droplets 202 and dust particles 203 in the flue gas 201 to move towards the inner wall of the separation tube body 104 of the separation tube 103 with an internal spiral structure. When they hit the inner wall, they are absorbed by the liquid film 204 on the inner wall. Finally, under the action of gravity, the liquid film 204 moves downward and drips into the recovery water tank 107 in the form of large droplets.

[0066] Figure 8 Legend: 101. Moisture recovery device for the flue gas after desulfurization in the power plant 103. Separation tube with an internal spiral structure 104. Separation tube body 105. Flow guide spiral 107. Recovery water tank 201, flue gas 202, tiny droplets 203, dust particles 204, liquid film Detailed implementation manners

[0067] An apparatus for recovering moisture in desulfurized flue gas of coal-fired power plants according to the present invention includes the following steps.

[0068] 1. The flue gas 201 after desulfurization in the power plant flows upward through the moisture recovery device 101 for desulfurized flue gas in the power plant. During this process, pollutants such as tiny droplets 202 and dust particles 203 in the flue gas 201 are captured and condensed for recovery by the moisture recovery device 101 for desulfurized flue gas in the power plant.

[0069] 2. The moisture recovery device 101 for desulfurized flue gas in the power plant is composed of numerous separation tubes 103 with an internal spiral structure. The separation tube 103 with an internal spiral structure is composed of an internal hollow separation tube body 104 and a diversion spiral 105. The flue gas 201 generates a rotational motion under the guidance of the diversion spiral 105.

[0070] 3. The centrifugal force generated by the rotation causes the tiny droplets 202 and dust particles 203 in the flue gas 201 to move towards the tube wall of the separation tube body 104 of the separation tube 103 with an internal spiral structure and are absorbed by the liquid film 204 on the tube wall when they touch the tube wall.

[0071] 4. Under the action of gravity, the liquid film 204 moves downward and drips into the recovery water tank 107 in the form of large droplets.

[0072] After the above steps, the water vapor and particles in the flue gas 201 are significantly reduced, achieving the purpose of recovering the moisture in the flue gas 201 and purifying the flue gas 201. The purified flue gas 201 is discharged from the end of the separation tube 103 with an internal spiral structure and can be directly discharged or further treated to meet the emission standards.

[0073] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A device for recovering moisture from flue gas after desulfurization in a power plant, characterized by: a. The moisture recovery device in the flue gas after desulfurization in a power plant is composed of one or more recovery modules. b. Each recovery module is composed of one or more separation tubes with an inner spiral structure. c. Each separation tube with an internal spiral structure consists of two parts: a separation tube body with a hollow interior and a flow guide spiral located inside the separation tube body.

2. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The flue gas flows from bottom to top through the moisture recovery device in the flue gas after desulfurization in the power plant, and the flow direction of the droplets after the moisture recovery is from top to bottom through the moisture recovery device in the flue gas after desulfurization in the power plant.

3. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The moisture recovery device in the flue gas after desulfurization in the power plant can be arranged in one layer or in multiple layers. Preferably, it is arranged in one layer.

4. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The moisture recovery device in the flue gas after desulfurization in the power plant can be arranged on the top floor of the existing desulfurization tower in the coal-fired power plant, or a new recovery tower can be built and arranged separately. Preferably, it is arranged on the top floor of the existing desulfurization tower.

5. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The separation tube body and the guide spiral are made of the same plastic material, preferably flame-retardant polypropylene.

6. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The length of the separation tube with an inner spiral structure is between 0.1 m and 0.6 m, preferably 0.2 m.

7. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The inner diameter of the separation tube body is the same as or slightly smaller than the outer diameter of the guide spiral 105 . Preferably, the inner diameter of the separation tube body 104 is slightly smaller than the outer diameter of the guide spiral 105 .

8. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The inner diameter of the separation tube body is between 10 mm and 100 mm, with a negative tolerance of 0.1 mm, preferably, 10 mm-0.1 mm.

9. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The outer diameter of the guide spiral is between 10 mm and 100 mm, and the outer diameter of the guide spiral is the same as the inner diameter of the separation tube body, with a positive tolerance of 0.1 mm. Preferably, the outer diameter of the guide spiral is 10 mm+0.1 mm.

10. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The guide spiral pitch is between 10 mm and 100 mm, and preferably, the guide spiral pitch is 10 mm.

11. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The guide spiral can be formed at one time with the separation tube body, or the guide spiral and the separation tube body can be processed separately and then combined into a separation tube with an internal spiral structure. Preferably, the guide spiral and the separation tube body are processed separately and then combined into a separation tube with an internal spiral structure.

12. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: Each recycling module is composed of a plurality of separation tubes with an internal spiral structure, and the processing method of a single recycling module is as follows: Method a. The separation tube body monomer and the guide spiral monomer are separately processed by an open mold injection molding method, and then the guide spiral monomer is inserted into the separation tube body monomer to form a separation tube monomer with an internal spiral structure, and then the plurality of separation tube monomers with an internal spiral structure are combined into a recycling module. Method b: using an open mold injection method to process a pre-assembled module and a guide spiral monomer composed of a plurality of separation tube body monomers, and then inserting the guide spiral monomers into the pre-assembled module to form a recovery module. Preferably, method b is used.

13. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: The guide spiral assembly method is as follows: Method aa. Insert the guide spiral monomer into the separation tube body monomer or pre-assembled module at room temperature to form a separation tube monomer or recovery module with an inner spiral structure. Method ab. First heat the separation tube body monomer or pre-assembled module, then insert the guide spiral at room temperature, and after cooling, form a separation tube monomer or recovery module with an inner spiral structure. Preferably, method ab is used.

14. The device for recovering moisture from flue gas after desulfurization in a power plant according to claim 1, characterized in that: In the guide spiral assembly method ab, the heating temperature of the separation tube body monomer or the pre-assembled module is 80-100°C, preferably 95°C.

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