Biogas condensation and dehumidification device based on tubular heat exchange structure

Abstract

The utility model discloses a biogas condensation dehumidification device based on a tubular heat exchange structure, which relates to the technical field of biogas dehumidification, and comprises a cylindrical shell, a plurality of heat exchange tubes are arranged in the cylindrical shell along the axial direction of the cylindrical shell, the inner wall of each heat exchange tube is provided with an anti-corrosion coating, and the outer wall of each heat exchange tube is provided with an anti-corrosion layer. The two ends of each heat exchange pipe are fixedly connected with the cylindrical shell through pipe plates, the two ends of the cylindrical shell are connected with an air inlet pipe and an air outlet pipe through reducer pipes respectively, the air inlet end of the air outlet pipe is fixedly connected with a folded plate type gas-liquid separator, and the large-diameter end of the reducer pipe connected with the air outlet pipe is connected with a drainage pipe. The two ends of the barrel wall of the barrel-shaped shell are connected with a water inlet pipe and a water outlet pipe respectively. The biogas condensation and dehumidification device based on the tubular heat exchange structure is good in condensation and dehumidification effect and long in service life, and the maintenance cost can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of biogas dehumidification technology, specifically a biogas condensation and dehumidification device based on a tubular heat exchange structure. Background Technology

[0002] In wastewater treatment processes, organic matter is decomposed by microorganisms to produce biogas. Before use, biogas typically requires desulfurization to remove corrosive gases such as hydrogen sulfide. After desulfurization, biogas usually carries a large amount of saturated water vapor.

[0003] Traditional biogas dehumidification devices mostly employ adsorption or gravity separation methods. However, these methods have several drawbacks. Adsorption requires frequent replacement of the adsorbent, leading to increased operating costs and low efficiency. Gravity separation, due to its technical limitations, cannot effectively handle micron-sized droplets, resulting in poor dehumidification. Furthermore, desulfurized biogas still retains small amounts of corrosive gases such as hydrogen sulfide and other impurities. When directly applying traditional shell-and-tube heat exchangers, these corrosive components easily erode the tube walls, causing corrosion and blockage, thus affecting dehumidification efficiency and equipment lifespan.

[0004] Therefore, it is necessary to propose a biogas condensation and dehumidification device based on a shell-and-tube heat exchange structure to solve the above problems. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] The purpose of this invention is to provide a biogas condensation and dehumidification device based on a shell-and-tube heat exchange structure to solve the problems mentioned in the background art.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model provides the following technical solution: a biogas condensation and dehumidification device based on a tubular heat exchange structure, comprising a cylindrical shell, wherein multiple heat exchange tubes are arranged axially inside the cylindrical shell, the inner wall of each heat exchange tube is coated with an anti-corrosion coating, both ends of the multiple heat exchange tubes are fixedly connected to the cylindrical shell via tube sheets, and both ends of the cylindrical shell are respectively connected to an inlet pipe and an outlet pipe via reducing pipes, wherein a baffle-type gas-liquid separator is fixedly connected to the inlet end of the outlet pipe, and a drain pipe is connected to the large-diameter end of the reducing pipe connected to the outlet pipe; and a water inlet pipe and a water outlet pipe are respectively connected to both ends of the cylindrical shell wall.

[0009] Preferably, the heat exchange tube density in the central region of the tube sheet is greater than the heat exchange tube density in its peripheral region.

[0010] Preferably, temperature sensors are provided at both the gas outlet end of the heat exchange tube and the liquid outlet end of the cylindrical shell.

[0011] Preferably, a variable frequency pump is connected to the water inlet pipe.

[0012] Preferably, the large-diameter end of the variable-diameter pipe connected to the air outlet pipe is provided with a liquid collection tank, the drain pipe is connected to the liquid collection tank, the liquid collection tank is provided with a liquid level sensor, and an electric valve is connected to the drain pipe.

[0013] Preferably, the interior of the cylindrical shell is fixedly connected with multiple arc-shaped baffles in an alternating manner.

[0014] Preferably, the spacing between the plurality of bow-shaped baffles decreases progressively from the cooling water inlet to the cooling water outlet.

[0015] Preferably, the surface of the anti-corrosion coating has a micro-textured surface.

[0016] (III) Beneficial Effects

[0017] Compared with the prior art, this utility model provides a biogas condensation and dehumidification device based on a shell-and-tube heat exchange structure, which has the following beneficial effects:

[0018] 1. This biogas condensation and dehumidification device based on a shell-and-tube heat exchange structure enables secondary dehumidification of sulfur-containing biogas by setting heat exchange tubes and a baffle-type gas-liquid separator. At the same time, by setting an anti-corrosion coating inside the heat exchange tubes, corrosion of the heat exchange tubes can be avoided, ensuring the condensation and dehumidification effect while improving the reliability and durability of the equipment.

[0019] 2. This biogas condensation and dehumidification device based on a shell-and-tube heat exchange structure uses a temperature sensor and a variable frequency pump to monitor the outlet temperature difference in real time and automatically adjust the cooling water flow rate to ensure that water vapor is fully condensed.

[0020] 3. This biogas condensation and dehumidification device based on a tubular heat exchange structure uses multiple bow-shaped baffles with progressively smaller spacing from the cooling water inlet to the cooling water outlet. The gradually decreasing spacing can increase the flow velocity and maintain a high heat transfer coefficient. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] In the diagram: 1. Inlet pipe; 2. Temperature sensor; 3. Heat exchanger tube; 4. Bow-shaped baffle; 5. Outlet pipe; 6. Tube sheet; 7. Baffle-type gas-liquid separator; 8. Outlet pipe; 9. Inlet pipe; 10. Variable frequency pump; 11. Reducer; 12. Liquid level sensor; 13. Drain pipe; 14. Electric valve; 15. Cylindrical shell; 17. Liquid collection tank. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0024] Please see Figure 1 As shown, a biogas condensation and dehumidification device based on a tubular heat exchange structure includes a cylindrical shell 15. Multiple heat exchange tubes 3 are arranged axially inside the cylindrical shell 15. The inner wall of the heat exchange tubes 3 is coated with an anti-corrosion coating. Both ends of the multiple heat exchange tubes 3 are fixedly connected to the cylindrical shell 15 through a tube sheet 6. The two ends of the cylindrical shell 15 are respectively connected to an inlet pipe 1 and an outlet pipe 8 through a reducing pipe 11. A baffle-type gas-liquid separator 7 is fixedly connected to the inlet end of the outlet pipe 8. A drain pipe 13 is connected to the large diameter end of the reducing pipe 11 connected to the outlet pipe 8. A water inlet pipe 9 and a water outlet pipe 5 are respectively connected to both ends of the cylindrical shell 15.

[0025] During installation, the cylindrical shell 15 is laid horizontally, with the drain pipe 13 located at the bottom of the reducer 11 so that condensate can drain by gravity. In use, cooling water is continuously supplied to the cylindrical shell 15 through the inlet pipe 9, and biogas to be dehumidified is supplied to the heat exchange tubes 3 through the air inlet pipe 1. Multiple heat exchange tubes 3 allow the cooling water and biogas to exchange heat, causing the saturated water vapor in the biogas to condense into water. Part of the condensate adheres to the inner wall of the heat exchange tubes 3, while the other part remains suspended in the biogas as small droplets. The condensate adhering to the inner wall flows out of the heat exchange tubes 3 under the propulsion of the airflow, while the small droplets suspended in the biogas undergo gas-liquid separation through the baffle-type gas-liquid separator 7. The separated condensate flows into the reducer 11. Finally, all condensate is discharged through the drain pipe 13.

[0026] By applying an anti-corrosion coating to the inner wall of the heat exchange tube 3, the corrosion of the inner wall by hydrogen sulfide in the biogas can be prevented, thereby improving the service life of the heat exchange tube 3. Preferably, the inner walls of the inlet pipe 1, the outlet pipe 8, and the reducer pipe 11 are all provided with an anti-corrosion coating. The anti-corrosion coating is a polytetrafluoroethylene coating.

[0027] To adapt to the biogas flow rate distribution and avoid local blockage, the density of heat exchange tubes 3 in the central region of tube sheet 6 is greater than that in the outer region.

[0028] In some embodiments, to facilitate control of the medium temperature difference, temperature sensors 2 are provided at both the gas outlet end of the heat exchange tube 3 and the liquid outlet end of the cylindrical shell 15. By detecting the temperature difference between the two media entering and exiting, it is determined whether the biogas condensation requirements are met, and the cooling water flow rate is increased or decreased according to the temperature difference.

[0029] Specifically, a variable frequency pump 10 is connected to the water inlet pipe 9. Both the variable frequency pump 10 and the temperature sensor 2 are connected to the controller to achieve automatic adjustment of the cooling water flow rate. By presetting a suitable temperature difference threshold in the controller, when the temperature difference between the two is higher than the threshold, the cooling water flow rate is reduced to reduce the temperature difference, thereby reducing the cooling water consumption and the energy consumption of the variable frequency pump 10. When the temperature difference between the two is lower than the threshold, the cooling water flow rate is increased to ensure that the water vapor is fully cooled.

[0030] In some embodiments, the large-diameter end of the reducer 11 connected to the vent pipe 8 is provided with a liquid collection tank 17, and a drain pipe 13 is connected to the liquid collection tank 17. A liquid level sensor 12 is provided inside the liquid collection tank 17, and an electric valve 14 is connected to the drain pipe 13. Both the liquid level sensor 12 and the electric valve 14 are connected to the controller. Condensate is collected through the liquid collection tank 17, and the liquid level in the liquid collection tank 17 is detected by the liquid level sensor 12. When the liquid level detected by the liquid level sensor 12 reaches a preset threshold, the controller controls the electric valve 14 to open, so that the condensate is discharged from the drain pipe 13.

[0031] To improve heat exchange efficiency, multiple arc-shaped baffles 4 are staggered and fixedly connected inside the cylindrical shell 15. These baffles force the cooling water to repeatedly laterally flush the heat exchange tubes 3, effectively preventing the cooling water from flowing directly from the inlet to the outlet of the cylindrical shell 15, ensuring the fluid flows through the entire heat exchange area, thereby enhancing the heat exchange effect. Preferably, the spacing between the multiple arc-shaped baffles 4 gradually decreases from the cooling water inlet to the cooling water outlet. As the cooling water continuously absorbs heat, its cooling capacity gradually decreases. To ensure the cooling effect, the gradually decreasing spacing can increase the flow velocity and maintain a high heat transfer coefficient.

[0032] To prevent blockage of heat exchange tube 3, the surface of the anti-corrosion coating is textured with micro-texture. By creating the micro-texture, turbulence can be generated in the fluid, thereby reducing particle deposition on the tube wall.

[0033] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A biogas condensation and dehumidification device based on a shell-and-tube heat exchange structure, characterized in that: The device includes a cylindrical shell (15), inside which multiple heat exchange tubes (3) are arranged along its axial direction. The inner wall of the heat exchange tubes (3) is provided with an anti-corrosion coating. Both ends of the multiple heat exchange tubes (3) are fixedly connected to the cylindrical shell (15) through tube plates (6). Both ends of the cylindrical shell (15) are respectively connected to an air inlet pipe (1) and an air outlet pipe (8) through a reducing pipe (11). The air inlet end of the air outlet pipe (8) is fixedly connected to a baffle-type gas-liquid separator (7). The large diameter end of the reducing pipe (11) connected to the air outlet pipe (8) is connected to a drain pipe (13). Both ends of the cylindrical shell (15) are respectively connected to a water inlet pipe (9) and a water outlet pipe (5).

2. The biogas condensation and dehumidification device based on a shell-and-tube heat exchange structure according to claim 1, characterized in that: The density of heat exchange tubes (3) in the central region of the tube sheet (6) is greater than the density of heat exchange tubes (3) in the outer region.

3. The biogas condensation and dehumidification device based on a shell-and-tube heat exchange structure according to claim 1, characterized in that: Temperature sensors (2) are provided at both the gas outlet end of the heat exchange tube (3) and the liquid outlet end of the cylindrical shell (15).

4. The biogas condensation and dehumidification device based on a shell-and-tube heat exchange structure according to claim 1, characterized in that: A variable frequency pump (10) is connected to the water inlet pipe (9).

5. A biogas condensation and dehumidification device based on a tubular heat exchange structure according to claim 1, characterized in that: The large-diameter end of the variable-diameter pipe (11) connected to the air outlet pipe (8) is provided with a liquid collection tank (17), the drain pipe (13) is connected to the liquid collection tank (17), the liquid collection tank (17) is provided with a liquid level sensor (12), and an electric valve (14) is connected to the drain pipe (13).

6. A biogas condensation and dehumidification device based on a tubular heat exchange structure according to claim 1, characterized in that: The cylindrical shell (15) has multiple bow-shaped baffles (4) fixedly connected inside in an alternating manner.

7. A biogas condensation and dehumidification device based on a tubular heat exchange structure according to claim 6, characterized in that: The spacing between the multiple bow-shaped baffles (4) decreases progressively from the cooling water inlet to the cooling water outlet.

8. A biogas condensation and dehumidification device based on a tubular heat exchange structure according to claim 1, characterized in that: The surface of the anti-corrosion coating has a micro-textured surface.

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