Wastewater discharge sealing device and water electrolysis hydrogen production system

Abstract

This utility model provides a wastewater discharge sealing device and a water electrolysis hydrogen production system. The wastewater discharge sealing device includes a tank, an intermediate cylinder, an inner cylinder, and a floating component. The tank has an inlet, an outlet, and a gas outlet connecting the outside and the internal space of the tank. The gas outlet is located at the top of the tank. The outlet is located at the bottom of the tank. The inlet is lower than the outlet. The intermediate cylinder is located inside the tank. The lower end of the intermediate cylinder is fixed to the bottom of the tank. A first cavity is formed between the intermediate cylinder and the tank. A liquid passage hole is located at the top of the intermediate cylinder. The liquid passage hole is higher than the inlet. The inner cylinder is located inside the intermediate cylinder. The lower end of the inner cylinder is fixed to the bottom of the tank. The inner cavity of the inner cylinder communicates with the outlet. The inner cylinder and the intermediate cylinder directly form a second cavity. The upper end of the inner cylinder is lower than the liquid passage hole. The floating component is located inside the intermediate cylinder. The floating component is positioned above the inner cylinder. The floating component is configured to rise and fall with the liquid level in the second cavity, thereby opening or sealing the upper port of the inner cylinder. This invention can prevent liquid seal failure.

Description

Technical Field

[0001] This utility model relates generally to the technical field of hydrogen production by water electrolysis, and more specifically to a wastewater discharge sealing device and a hydrogen production system by water electrolysis. Background Technology

[0002] In current hydrogen production processes via water electrolysis, the periodically discharged wastewater contains residual hydrogen. Direct discharge of this hydrogen can easily lead to accumulation and explosion, posing a safety hazard. Preventing backfire is crucial. Existing water seal devices use liquid seals to prevent gas backflow. However, when the upstream wastewater pressure is high (containing hydrogen), it can cause a pressure increase in the water seal device, potentially leading to the complete discharge of liquid from the water seal tank and causing seal failure. Subsequently, hydrogen will also be discharged from the water seal device through the overflow pipe, posing a safety risk.

[0003] Therefore, there is a need to provide a wastewater discharge sealing device and a water electrolysis hydrogen production system to at least partially solve the above problems. Utility Model Content

[0004] The present invention includes a series of simplified concepts, which will be further explained in detail in the detailed description section. This present invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0005] To at least partially solve the above problems, the first aspect of this utility model provides a sewage discharge sealing device, which includes a tank, an intermediate cylinder, an inner cylinder, and a floating component;

[0006] The tank body has an air outlet, a liquid outlet, and a liquid inlet that connect the outside and the internal space of the tank body. The air outlet is located at the top of the tank body, the liquid outlet is located at the bottom of the tank body, and the liquid inlet is located lower than the air outlet along the vertical direction of the tank body.

[0007] The intermediate cylinder is disposed in the internal space of the tank body. The lower end of the intermediate cylinder is fixed to the bottom of the tank body. The side of the intermediate cylinder is spaced apart from the tank body to form a first cavity. The upper part of the intermediate cylinder is provided with a liquid passage hole that connects the first cavity and the internal space of the intermediate cylinder. Along the vertical direction, the liquid passage hole is located higher than the liquid inlet.

[0008] The inner cylinder is disposed in the internal space of the intermediate cylinder. The lower end of the inner cylinder is fixed to the bottom of the tank body, and the inner cavity of the inner cylinder is connected to the liquid outlet. The side of the inner cylinder is spaced apart from the intermediate cylinder to form a second cavity. Along the vertical direction, the upper end of the inner cylinder is lower than the opening position of the liquid passage hole.

[0009] The floating element is located inside the intermediate cylinder and is positioned above the inner cylinder. The floating element is configured to rise as the liquid level in the second cavity rises to open the upper port of the inner cylinder, and to fall as the liquid level in the second cavity falls until the upper port of the inner cylinder is blocked.

[0010] According to the first aspect of the present invention, when the pressure inside the sewage sealing device increases due to the presence of a large amount of hydrogen, the floating component can block the upper port of the inner cylinder when the liquid level in the second chamber drops to a certain level, thereby preventing the liquid from being completely discharged and thus achieving the technical objective of preventing liquid seal failure.

[0011] Optionally, the floating element is at least partially spaced from the side of the intermediate cylinder.

[0012] Optionally, the sewage sealing device further includes an overflow pipe connected to the outlet, the outlet end of the overflow pipe being no higher than the upper port of the inner cylinder in the vertical direction, and at least a portion of the overflow pipe being lower than the outlet end of the overflow pipe.

[0013] Optionally, the top of the intermediate cylinder is lower than the top of the tank body;

[0014] The sewage sealing device also includes a blocking member connected to the top of the intermediate cylinder. When the floating member is positioned to block the upper port of the inner cylinder, the floating member and the blocking member are spaced apart along the vertical direction.

[0015] Optionally, the top of the intermediate cylinder extends to the top of the tank body;

[0016] In a plane perpendicular to the vertical direction, the air outlet is located outside the orthographic projection of the intermediate cylinder.

[0017] Optionally, the floating element is configured as a buoy;

[0018] The center of the float is located below the liquid passage.

[0019] Optionally, the side of the tank is provided with a liquid replenishment port.

[0020] The replenishment port is located above the inlet port in the vertical direction.

[0021] Optionally, the number of liquid passage holes is multiple, and the multiple liquid passage holes are arranged at intervals along the circumferential direction of the intermediate cylinder; and / or

[0022] The number of liquid passage holes is multiple, and the multiple liquid passage holes are arranged at intervals along the vertical direction.

[0023] Optionally, the tank body includes a tank component and a cover component, the top of the tank component having an opening, and the cover component being detachably connected to the tank component at the opening;

[0024] The air outlet is located on the cover component.

[0025] The second aspect of this utility model provides a water electrolysis hydrogen production system, which includes the above-mentioned wastewater discharge sealing device.

[0026] According to the water electrolysis hydrogen production system of the second aspect of this utility model, by applying the above-mentioned wastewater discharge sealing device, the liquid can be prevented from being completely discharged, thereby achieving the technical objective of preventing liquid seal failure and improving the operational stability of the water electrolysis hydrogen production system. Attached Figure Description

[0027] The following drawings, which illustrate embodiments of the present invention, are incorporated herein as part of the present invention for understanding the invention. The drawings show embodiments of the present invention and their descriptions, serving to explain the principles of the present invention. In the drawings,

[0028] Figure 1 This is a schematic diagram of a sewage sealing device according to a preferred embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100: Wastewater discharge sealing device; 10: Tank body

[0031] 111: Tank component 11a: Opening

[0032] 111b: Liquid inlet; 11c: Liquid outlet

[0033] 111d: Liquid replenishment port; 11e: Second flange section

[0034] 112: Intermediate cylinder 12a: Liquid passage hole

[0035] 113: Inner cylinder 14: First cavity

[0036] 115: Second cavity 16: Inner cavity

[0037] 120: Cover component 21: First flange section

[0038] 122: Air outlet; 30: Floating component

[0039] 140: Overflow pipe; 41: Outlet end

[0040] 150: Blocking component H: Vertical direction Detailed Implementation

[0041] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with embodiments of the present invention.

[0042] To fully understand the embodiments of this utility model, a detailed structure will be presented in the following description. Obviously, the implementation of the embodiments of this utility model is not limited to the specific details familiar to those skilled in the art.

[0043] It should be understood that the terminology used herein is intended solely to describe specific implementation methods.

[0044] Furthermore, as not limiting this invention, the singular forms “a,” “an,” and “the” / “the” are also intended to include the plural forms, unless the context clearly indicates otherwise. When the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0045] The ordinal numbers such as "first" and "second" used in this utility model are merely identifiers and do not have any other meaning, such as a specific order. Furthermore, for example, the term "first component" does not imply the existence of a "second component," and the term "second component" does not imply the existence of a "first component." It should be noted that the terms "upper," "lower," "front," "rear," "left," "right," "inner," "outer," and similar expressions used in this utility model are for illustrative purposes only and are not intended to be limiting.

[0046] The terms “center,” “parallel,” “perpendicular,” “aligned,” and “symmetrical” used in this invention do not have to be precise, but can include typical engineering tolerances.

[0047] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0048] For a more detailed description, these accompanying drawings illustrate representative embodiments of the present invention and are not intended to limit the scope of the invention.

[0049] The water seal device is an important component of the drainage system in the water electrolysis hydrogen production system. Its principle is to separate hydrogen from water through the pressure of the water column, thereby preventing air from entering the hydrogen production system and reducing the risk of explosion when hydrogen and air mix. It plays an important role in the safety of the drainage system.

[0050] Currently, in existing water electrolysis hydrogen production processes, the periodically discharged wastewater contains residual hydrogen. Direct discharge of this hydrogen can easily lead to accumulation and explosion, posing a safety hazard. It is necessary to prevent gas backfire. Existing water seal tanks use liquid seals to prevent gas backflow. However, when the pressure of the discharged liquid at the front end is high (containing hydrogen), the pressure in the water seal tank increases, causing the entire liquid level to be discharged from the tank, rendering the liquid seal ineffective. Subsequently, hydrogen also escapes from the water seal tank through the overflow pipe, leading to a safety risk.

[0051] This application relates to the field of water electrolysis for hydrogen production, specifically to a wastewater discharge sealing device that combines gas-liquid separation, pressure buffering, and backfire prevention functions. The wastewater discharge sealing device is applied to a water electrolysis hydrogen production system to treat wastewater discharged from the system. See below. Figure 1 The wastewater discharge sealing device and the water electrolysis hydrogen production system having the same provided according to embodiments of the present invention will be described.

[0052] An embodiment of this utility model provides a sewage discharge sealing device 100. The sewage discharge sealing device 100 includes a tank 110, an intermediate cylinder 112, an inner cylinder 113, and a floating component 130.

[0053] The tank body 110 has an inlet 111b, an outlet 111c, and an outlet 122 that connect the external environment and the internal space of the tank body 110. The outlet 122 is located at the top of the tank body 110. The outlet 111c is located at the bottom of the tank body 110. Along the vertical direction of the tank body 110, the inlet 111b is positioned lower than the outlet 122. The inlet 111b is used to connect to an upstream drainage pipe.

[0054] An intermediate cylinder 112 is disposed within the internal space of the tank body 110. The lower end of the intermediate cylinder 112 is fixed to the bottom of the tank body 110. The side of the intermediate cylinder 112 is spaced apart from the tank body 110 to form a first cavity 114. A liquid passage 112a is provided on the upper part of the intermediate cylinder 112, communicating with the first cavity 114 and the internal space of the intermediate cylinder 112. In the vertical direction, the liquid passage 112a is positioned higher than the liquid inlet 111b.

[0055] The inner cylinder 113 is located within the internal space of the intermediate cylinder 112. The lower end of the inner cylinder 113 is fixed to the bottom of the tank body 110. The inner cavity 116 of the inner cylinder 113 communicates with the liquid outlet 111c. The side of the inner cylinder 113 is spaced apart from the intermediate cylinder 112 to form a second cavity 115. In the vertical direction, the upper end of the inner cylinder 113 is lower than the opening position of the liquid passage 112a.

[0056] The floating element 130 is located inside the intermediate cylinder 112. The floating element 130 is positioned above the inner cylinder 113. The floating element 130 is configured to rise as the liquid level in the second chamber 115 rises to open the upper port of the inner cylinder 113, and to fall as the liquid level in the second chamber 115 falls until it blocks the upper port of the inner cylinder 113.

[0057] The liquid passage 112a connects to the first chamber 114 and the second chamber 115. When the liquid level in the first chamber 114 reaches the liquid passage 112a, the liquid will flow into the second chamber 115 through the liquid passage 112a. This prevents the liquid from flowing directly into the inner cylinder 113.

[0058] During use, upstream wastewater is transported to tank 110 via inlet 111b. Inside tank 110, the wastewater first enters the first chamber 114, where gas-liquid separation is completed, and hydrogen is discharged from outlet 122. When the liquid level in the first chamber 114 rises to the position of through-hole 112a, the liquid enters the internal space of the intermediate cylinder 112 through through-hole 112a. When the liquid level in the intermediate cylinder 112 rises above the inner cylinder 113, the floating element 130 rises due to buoyancy, thereby detaching from the upper port of the inner cylinder 113. Liquid then flows through the gap between the floating element 130 and the inner cylinder 113 into the upper port of the inner cylinder 113, and the liquid flowing into the inner cylinder 113 is finally discharged outwards through outlet 111c. As the liquid level in the intermediate cylinder 112 drops below the upper port of the inner cylinder 113, the floating element 130 falls back to the upper port of the inner cylinder 113 and blocks the upper port of the inner cylinder 113, preventing the liquid in the intermediate cylinder 112 from flowing into the inner cylinder 113, thereby preventing the liquid in the intermediate cylinder 112 from continuing to be discharged.

[0059] According to the embodiment of the present utility model, when the pressure inside the sewage sealing device 100 increases due to the presence of a large amount of hydrogen, the floating member 130 can block the upper port of the inner cylinder 113 when the liquid level in the second chamber 115 drops to a certain level, thereby preventing the liquid from being completely discharged, and thus achieving the technical purpose of preventing liquid seal failure.

[0060] In some embodiments, the float 130 is at least partially spaced from the side of the intermediate cylinder 112. This facilitates the flow of liquid from the liquid passage 112a to the second cavity 115 through the gap between the float 130 and the intermediate cylinder 112.

[0061] In some other embodiments, the dimension of the floating member 130 in the vertical direction DH is smaller than its dimension in the horizontal direction. Through holes may be formed on the edges of the floating member 130. These through holes correspond to the dimensions of the second cavity 115 in the vertical direction DH. The through holes allow liquid to flow from the upper side to the lower side of the floating member 130, thereby allowing the liquid to flow into the second cavity 115. For example, the floating member 130 may be constructed in a disc shape.

[0062] In some embodiments, the wastewater sealing device 100 further includes an overflow pipe 140. The overflow pipe 140 is connected to the outlet 111c. The outlet end 141 of the overflow pipe 140 is not higher than the upper port of the inner cylinder 113 in the vertical direction DH. At least a portion of the overflow pipe 140 is lower than the outlet end 141 of the overflow pipe 140. The overflow pipe 140 always retains a certain amount of liquid, thereby isolating air and preventing backfire. Furthermore, since the outlet end 141 of the overflow pipe 140 is not higher than the upper port of the inner cylinder 113 in the vertical direction DH, according to the principle of connecting pipes, it can be ensured that the liquid level in the second chamber 115 can drop below the upper port of the inner cylinder 113, thereby allowing the floating member 130 to fall back to the position blocking the upper port of the inner cylinder 113.

[0063] In some embodiments, the top of the intermediate cylinder 112 is lower than the top of the tank body 110. The wastewater sealing device 100 also includes a blocking member 150. The blocking member 150 is connected to the top of the intermediate cylinder 112. Along the vertical direction DH, the distance between the inner cylinder 113 and the blocking member 150 is greater than the maximum size of the floating member 130. In other words, when the floating member 130 is located at the position blocking the upper port of the inner cylinder 113, the floating member 130 and the blocking member 150 are spaced apart along the vertical direction DH. By setting the top of the intermediate cylinder 112 to be lower than the top of the tank body 110, more space can be formed above the intermediate cylinder 112 for buffering hydrogen, reducing the risk of a sharp increase in front-end pressure. By providing the blocking member 150, the floating member 130 can be prevented from moving out of the intermediate cylinder 112, thereby preventing the floating member 130 from moving to the position of the outlet 122 and blocking the outlet 122, thereby improving the flexibility of the outlet 122 in terms of position selection.

[0064] Alternatively, the blocking element 150 may be a plate with holes.

[0065] Alternatively, the blocking element 150 can also be a frame structure made of filamentous, rod-shaped, or strip-shaped objects. For example, a cross-shaped structure made of stainless steel wire.

[0066] In some other embodiments not shown, the top of the intermediate cylinder 112 extends to the top of the tank body 110. In a plane perpendicular to the vertical direction DH, the vent 122 is located outside the orthographic projection of the intermediate cylinder 112. In other words, the vent 122 is misaligned with the intermediate cylinder 112. This prevents the floating element 130 from blocking the vent 122.

[0067] In some embodiments, the float 130 is configured as a float. The center of the float is located below the liquid passage 112a. When the liquid level in the first chamber 114 rises to the position of the liquid passage 112a, the liquid in the first chamber 114 flows through the liquid passage 112a to the upper spherical surface of the float, and then flows downward into the second chamber 115 through the gap between the float and the intermediate cylinder 112. It is understood that in order to allow the float to rise and fall under the action of buoyancy within the intermediate cylinder 112, the float is in clearance fit with the inner circumferential surface of the intermediate cylinder 112.

[0068] Optionally, the diameter of the float is larger than the inner diameter of the inner cylinder 113, and the diameter of the float is smaller than the inner diameter of the intermediate cylinder 112.

[0069] To ensure the float can reliably and stably seal the intermediate cylinder 112, the float is made of hollow metal or a non-metallic ball of equivalent mass. The hollow metal ball can be a hollow stainless steel ball.

[0070] In some embodiments, a replenishment port 111d is provided on the side of the tank body 110. The replenishment port 111d is located above the inlet port 111b in the vertical direction DH. The replenishment port 111d is used for replenishing water to establish the initial liquid level.

[0071] In some other embodiments, if the liquid replenishment port 111d is not provided, water or liquid can be replenished using the air outlet 122 to establish the initial liquid level.

[0072] In some embodiments, there are multiple liquid passage holes 112a. The multiple liquid passage holes 112a are arranged at intervals along the circumferential direction of the intermediate cylinder 112. This facilitates the simultaneous flow of liquid from different circumferential positions of the first cavity 114 into the internal space of the intermediate cylinder 112, thereby improving the liquid flow efficiency.

[0073] In some embodiments, there are multiple liquid passage holes 112a. The multiple liquid passage holes 112a are arranged at intervals along the vertical direction DH. This allows the liquid in the first cavity 114 to flow into the internal space of the intermediate cylinder 112 simultaneously from different positions in the vertical direction DH, thereby improving the liquid flow efficiency.

[0074] In some embodiments, the tank 110 includes a tank component 111 and a cover component 120. The top of the tank component 111 has an opening 111a. The cover component 120 is detachably connected to the tank component 111 at the opening 111a. An air outlet 122 is located on the cover component 120. A liquid inlet 111b and a liquid outlet 111c are located on the tank component 111. The cover component 120 is detachably connected to the pipe component for easy disassembly, facilitating cleaning and maintenance. The aforementioned replenishment port 111d is also located on the tank component 111. Compared to the conventional method of locating the replenishment port 111d on the cover component 120, this reduces the structural complexity and weight of the cover component 120. Furthermore, since the replenishment port 111d is a liquid interface, arranging all liquid interfaces on the tank component 111 facilitates the layout and centralized management of the liquid pipelines.

[0075] Optionally, the cover member 120 includes a first flange portion 121. The tank body 110 includes a second flange portion 111e. The first flange portion 121 and the second flange portion 111e are adapted to be connected by fasteners such as bolts.

[0076] The following specific embodiment further illustrates the sewage discharge sealing device 100 of this utility model:

[0077] The wastewater discharge sealing device 100 consists of a three-layer structure: a tank 110, an intermediate cylinder 112, and an inner cylinder 113. The intermediate cylinder 112 is placed inside the tank 110. The inner cylinder 113 is placed inside the intermediate cylinder 112. The height of the inner cylinder 113 is lower than that of the intermediate cylinder 112. A hollow stainless steel float (as a floating element 130) is installed on the inner cylinder 113. A baffle (as a blocking element 150) is installed above the float to prevent the float from moving upward and blocking the vent 122. The wastewater discharge sealing device 100 has four ports: a liquid replenishment port 111d, a liquid inlet port 111b, a vent 122, and a liquid outlet port 111c. The liquid replenishment port 111d is used to replenish water to establish the initial liquid level. The liquid inlet port 111b is connected to the upstream system for drainage. The vent 122 is used for the safe discharge of gas after gas-liquid separation, and is connected to pipelines and safety devices to lead to a safe place for venting. The liquid outlet port 111c is used to connect to the overflow pipe 140. When the water seal level is higher than the outlet end 141 of the overflow pipe 140, water flows out from the overflow pipe 140. When upstream sewage is discharged, the gas-liquid mixture enters the tank 110 and undergoes gas-liquid separation under gravity. The gas is discharged from the upper gas outlet 122, and the liquid remains in the tank 110. The liquid level in the tank 110 rises continuously as the upstream sewage discharge increases. When the liquid level reaches the top of the intermediate cylinder 112, it enters the internal space of the intermediate cylinder 112 through the liquid passage 112a. The liquid level in the intermediate cylinder 112 continues to rise (it can be understood that there is a gap between the float and the inner wall of the intermediate cylinder 112 to allow the liquid to flow down). When it reaches the height of the float, the buoyancy lifts the float up, and the gap between the float and the top of the inner cylinder 113 opens. The liquid is discharged from the sewage seal device 100 through the inner cylinder 113 and the overflow pipe 140 in sequence. As the overflow pipe 140 drains water, the liquid level in the intermediate cylinder 112 continuously decreases, causing the float to drop in height until it loses buoyancy and falls back to the upper port of the inner cylinder 113, thus sealing the upper port of the inner cylinder 113.

[0078] The wastewater sealing device 100 of this invention has the functions of gas-liquid separation, dynamic water sealing, and pressure protection. It can solve the problem of safety hazards caused by hydrogen gas being discharged from the water sealing device through the overflow pipe 140 when the water seal level fails in the prior art. This invention has a compact structure and low cost, and effectively solves the problem of insufficient reliability of the liquid seal in existing water seal tanks.

[0079] An embodiment of this utility model provides a water electrolysis hydrogen production system, which includes the above-mentioned wastewater discharge sealing device 100.

[0080] According to the embodiments of the present invention, the water electrolysis hydrogen production system, by applying the above-mentioned wastewater discharge sealing device 100, can prevent the liquid from being completely discharged, thereby achieving the technical objective of preventing liquid seal failure and improving the operational stability of the water electrolysis hydrogen production system.

[0081] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of the invention. Terms such as “set” appearing herein can refer to either a component being directly attached to another component or a component being attached to another component via an intermediary. A feature described in one embodiment may be applied, alone or in combination with other features, to another embodiment, unless that feature is not applicable in that other embodiment or is otherwise stated.

[0082] This utility model has been described through the above embodiments. However, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit this utility model to the described embodiments. Those skilled in the art will understand that many more variations and modifications can be made based on the teachings of this utility model, and all such variations and modifications fall within the scope of protection claimed by this utility model.

Claims

1. A blowdown water seal apparatus, characterized by, The sewage discharge sealing device includes a tank, an intermediate cylinder, an inner cylinder, and a floating component; The tank body has an air outlet, a liquid outlet, and a liquid inlet that connect the outside and the internal space of the tank body. The air outlet is located at the top of the tank body, the liquid outlet is located at the bottom of the tank body, and the liquid inlet is located lower than the air outlet along the vertical direction of the tank body. The intermediate cylinder is disposed in the internal space of the tank body. The lower end of the intermediate cylinder is fixed to the bottom of the tank body. The side of the intermediate cylinder is spaced apart from the tank body to form a first cavity. The upper part of the intermediate cylinder is provided with a liquid passage hole that connects the first cavity and the internal space of the intermediate cylinder. Along the vertical direction, the liquid passage hole is located higher than the liquid inlet. The inner cylinder is disposed in the internal space of the intermediate cylinder. The lower end of the inner cylinder is fixed to the bottom of the tank body, and the inner cavity of the inner cylinder is connected to the liquid outlet. The side of the inner cylinder is spaced apart from the intermediate cylinder to form a second cavity. Along the vertical direction, the upper end of the inner cylinder is lower than the opening position of the liquid passage hole. The floating element is located inside the intermediate cylinder and is positioned above the inner cylinder. The floating element is configured to rise as the liquid level in the second cavity rises to open the upper port of the inner cylinder, and to fall as the liquid level in the second cavity falls until the upper port of the inner cylinder is blocked.

2. The trap according to claim 1, wherein The floating element is at least partially spaced from the side of the intermediate cylinder.

3. The sewage discharge sealing device according to claim 1 or 2, characterized in that, The sewage discharge sealing device also includes an overflow pipe connected to the liquid outlet. The outlet end of the overflow pipe is not higher than the upper port of the inner cylinder in the vertical direction, and at least a portion of the overflow pipe is lower than the outlet end of the overflow pipe.

4. The sewage discharge sealing device according to claim 3, characterized in that, The top of the intermediate cylinder is lower than the top of the tank body; The sewage sealing device also includes a blocking member connected to the top of the intermediate cylinder. When the floating member is positioned to block the upper port of the inner cylinder, the floating member and the blocking member are spaced apart along the vertical direction.

5. The sewage discharge sealing device according to claim 3, characterized in that, The top of the intermediate cylinder extends to the top of the tank body; In a plane perpendicular to the vertical direction, the air outlet is located outside the orthographic projection of the intermediate cylinder.

6. The sewage discharge sealing device according to claim 1 or 2, characterized in that, The floating component is configured as a buoy; The center of the float is located below the liquid passage.

7. The sewage sealing device according to claim 1 or 2, characterized in that, The tank body is provided with a liquid replenishment port on its side. The replenishment port is located above the inlet in the vertical direction.

8. The sewage sealing device according to claim 1 or 2, characterized in that, The number of liquid passage holes is multiple, and the multiple liquid passage holes are arranged at intervals along the circumferential direction of the intermediate cylinder; and / or The number of liquid passage holes is multiple, and the multiple liquid passage holes are arranged at intervals along the vertical direction.

9. The sewage discharge sealing device according to claim 1 or 2, characterized in that, The tank body includes a tank component and a cover component, the top of the tank component has an opening, and the cover component is detachably connected to the tank component at the opening; The air outlet is located on the cover component.

10. A hydrogen production system by water electrolysis, characterized by, The water electrolysis hydrogen production system includes the wastewater discharge sealing device as described in any one of claims 1 to 9.

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