Unpowered soil ventilation system of bioretention facility and control method of unpowered soil ventilation system

Abstract

The invention provides an unpowered soil ventilation system for a bioretention facility, the system comprises a water storage module and a ventilation module which are arranged in a soil layer and are communicated with each other, and the water storage module is communicated with the interior of the soil layer so as to receive rainwater in the soil layer and provide aeration for the soil layer; a water outlet capable of being selectively opened and closed is formed in one side of the ventilation module, rainwater in the ventilation module can be discharged through the water outlet, and external air can be fed into the ventilation module and the water storage module through the water outlet; a lifting supporting unit and a discharge door control unit are further arranged, the lifting supporting unit can selectively provide support for the discharge door control unit according to the change of the liquid level in the ventilation module, and the discharge door control unit can control opening and closing of the water outlet according to the change of the liquid level in the ventilation module; the water storage module and the ventilation module are modularly combined, so that the uniform ventilation effect under the greenhouse soil of the regional greenbelt is achieved by only arranging a single ventilation module or a small number of ventilation modules, and the cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of soil aeration systems, and in particular to an unpowered soil aeration system for a bioretention facility and a control method thereof. Background Art

[0002] The bioretention facilities in the prior art have a high degree of soil sealing, and it is difficult for outside air to enter the soil. As a result, the bioretention facilities will cause the soil pores to be filled with water due to long-term water accumulation. The water inside the soil will occupy the air space, causing the oxygen inside the soil to be discharged, making the soil compacted.

[0003] Since plant roots in the soil require oxygen for respiration, the difficulty for outside air to enter the soil of the bioretention facility will also result in the plant roots not having sufficient oxygen for respiration, reducing the growth efficiency of the plants and thus affecting the landscape and ecological benefits of the bioretention facility.

[0004] The difficulty for outside air to enter the soil of the bioretention facility will accelerate the formation of an anaerobic environment in the soil, causing the soil to produce anaerobic by-products (such as harmful or odorous gases such as hydrogen sulfide and methane). At the same time, since oxygen is the key condition for nitrifying bacteria to convert ammonia nitrogen into nitrate, the reduction of air in the soil will also weaken nitrification and reduce the soil's denitrification capacity. In addition, anaerobic conditions will also increase the possibility of metal ions (such as iron, manganese, etc.) in the soil being reduced and released into the water, thereby causing secondary pollution.

[0005] The existing patent application number CN2018100091649 discloses a device for soil aeration, and the disclosed solution is to achieve soil oxygenation by introducing oxygen-containing air into the aeration pipe. However, the defects and shortcomings of this solution are: 1) The aeration tube is a single aeration tube with a small radiation area. Therefore, multiple aeration tubes need to be buried to achieve the oxygenation effect of a larger range of soil. However, the burying operation of multiple aeration tubes is relatively cumbersome, which makes this method huge in workload and cannot achieve uniform aeration of the soil.

[0006] 2) In the existing rainwater garden green space, oxygen-containing gas needs to be pumped into the aeration pipe by air hammer and other equipment for soil aeration operation each time aeration is performed, which requires additional power. In addition, since each aeration requires manual operation, the aeration frequency is limited.

[0007] Therefore, it is urgent to provide a new solution to solve the defects and shortcomings in the above-mentioned prior art. Summary of the invention

[0008] In order to solve the defects and shortcomings in the prior art, the present invention provides an unpowered soil aeration system for a bioretention facility and a control method thereof.

[0009] The specific solution provided by the present invention is as follows: A non-powered soil aeration system for a bioretention facility, the system comprising a water storage module and a ventilation module which are arranged inside the soil layer and are interconnected. The water storage module is connected to the inside of the soil layer so as to be able to receive rainwater in the soil layer and provide aeration to the soil layer; a drain outlet which can be selectively opened and closed is arranged on one side of the ventilation module, and through the drain outlet, rainwater inside the ventilation module can be discharged and external air can be sent into the ventilation module and the water storage module through the drain outlet; characterized in that: a lifting support unit and a drain door control unit are further arranged inside the ventilation module, the lifting support unit can selectively provide support for the drain door control unit according to the change of the liquid level inside the ventilation module, and the drain door control unit can control the opening and closing of the drain outlet according to the change of the liquid level inside the ventilation module.

[0010] As a further preferred embodiment of the present invention, the lifting support unit comprises a support float which can lift and lower synchronously with the liquid level inside the ventilation module. One side of the support float is connected to a support member through a transmission member which is rotatably arranged inside the ventilation module, and the support float drives the support member to lift and lower inside the ventilation module through the transmission member.

[0011] As a further preferred embodiment of the present invention, a guide rail is fixedly arranged inside the ventilation module, and the support member is located inside the guide rail and can lift and lower relative to the guide rail.

[0012] As a further preferred embodiment of the present invention, the drain door control unit comprises a balance member which is rotatably arranged inside the ventilation module. The bottom of one side of the balance member can abut against the top of the support member, the other side of the balance member is fixedly connected to a drain door float, the drain door float is flexibly connected to the drain door through a connecting member, and the drain door is adapted to the drain outlet.

[0013] As a further preferred embodiment of the present invention, the balance member is rotatably arranged inside the ventilation module through a hinge point, and the balance member is made of a water-absorbing material.

[0014] As a further preferred embodiment of the present invention, an extension part which abuts against the support member is arranged on one side of the balance member close to the support member.

[0015] As a further preferred embodiment of the present invention, when the balance member does not absorb water, the sum of the masses of the balance member and the extension part on the left side of the hinge point is equal to the sum of the masses of the balance member and the drain door float on the right side of the hinge point.

[0016] As a further preferred embodiment of the present invention, when the rainwater inside the initial ventilation module has not reached the first liquid level, the lifting support unit provides support for the drain gate control unit, and when the rainwater inside the ventilation module rises to the first liquid level, the lifting support unit cancels the support for the drain gate control unit, and when the rainwater inside the ventilation module drops to the third liquid level, the lifting support unit resumes the support for the drain gate control unit; and the first liquid level is higher than the third liquid level.

[0017] As a further preferred embodiment of the present invention, when the rainwater inside the initial ventilation module has not reached the second liquid level, the drain gate control unit does not rotate inside the ventilation module to control the closing of the drain opening. When the rainwater inside the ventilation module rises to the second liquid level, the drain gate control unit rotates to control the opening of the drain opening. And when the rainwater inside the ventilation module drops to the third liquid level, the drain gate control unit rotates to its original position under the support of the lifting support unit and relies on the self-weight of the drain gate to control the closing of the drain opening; and the second liquid level is higher than the first liquid level.

[0018] Furthermore, the present invention also provides a control method for a non-powered soil ventilation system of a bioretention facility, which is characterized in that it includes the following steps: S1: When it starts to rain, the rainwater seeps into the inside of the water storage module through the soil layer. The rainwater inside the water storage module flows into the inside of the ventilation module. The drain gate closes the drain opening due to its own gravity, and the rainwater cannot drain through the drain opening. S2: Since the closing of the drain opening causes the liquid levels inside the water storage module and the ventilation module to continuously rise with the increase in rainfall, the continuously rising liquid level inside the water storage module squeezes the space position of the gas inside the water storage module, causing the gas inside the water storage module to gradually move upward to the soil layer until it is discharged, completing the aeration of the soil layer. S3: The continuously rising liquid level also drives the support float to rise synchronously. The support float drives the support member to descend synchronously along the guide rail through the transmission member. S4: When the liquid level inside the water storage module reaches the first liquid level, the support member descends along the guide rail and disengages from the drain gate control unit, and the supporting effect of the support member on the drain gate control unit disappears. S5: When the liquid level inside the ventilation module rises to the second liquid level, it drives the drain gate float to rotate counterclockwise with the hinge point as the center. The left side of the balance member enters below the liquid level and absorbs water to increase weight. The weights on the left and right sides of the balance member are no longer balanced. The mass on the left side of the hinge point is greater than the mass on the right side. At this time, even if the liquid level drops, the balance member will drive the drain gate float to maintain the current angle unchanged. The drain gate float controls the opening of the drain gate through the connecting member. The water inside the interconnected water storage module and ventilation module is discharged into the subsequent rainwater well or rainwater pipe network through the drain opening. S6: When the liquid level inside the ventilation module is lower than the pipe orifice of the drain pipe, the external air enters the inside of the ventilation module from the drain pipe and finally enters the inside of the water storage module. S7: Until the liquid level inside the ventilation module drops to the third liquid level, at this time the support float moves downward synchronously with the liquid level. The support float drives the support member to rise synchronously along the guide rail through the transmission member. Until the support member upwardly abuts against the left extension of the balance member and then continues to rise, thereby driving the balance member and the drain door float to rotate clockwise along the hinge point. At this time, the weights on the left and right sides of the balance member are restored to balance, and the drain door pulls the drain door float under its own gravity to control the closing of the drain opening.

[0019] Compared with the prior art, the technical effects that the present invention can achieve include: 1) The present invention provides a biological retention facility unpowered soil ventilation system and its control method. By modularly combining the water storage module and the ventilation module, it is possible to achieve uniform ventilation of the soil under the regional green space facilities by arranging only one piece or a small number of ventilation modules, reducing construction operations and costs.

[0020] 2) The present invention provides a biological retention facility unpowered soil ventilation system and its control method. It can perform a set of ventilation cycles for the soil every time it rains. Compared with traditional aeration mechanisms, the ventilation frequency of the soil is more frequent, thereby further increasing the ventilation effect on the soil.

[0021] 3) The present invention provides a biological retention facility unpowered soil ventilation system and its control method. By using rainfall as the power to start the cycle of the entire soil ventilation system, no additional power support is required, no manual operation is needed, and the energy used is green, environmentally friendly, clean and can be recycled sustainably. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure shows a schematic structural diagram of the ventilation system provided by the present invention in its initial state.

[0023] Figure 2 The figure shows an installation diagram of the structure of the ventilation system provided by the present invention.

[0024] Figure 3 The figure shows a state structure diagram of the ventilation system provided by the present invention at the start of rainfall.

[0025] Figure 4 The figure shows a state structure diagram of the ventilation system provided by the present invention at the start of aeration.

[0026] Figure 5 The figure shows a state structure diagram of the ventilation system provided by the present invention during drainage.

[0027] Figure 6 The figure shows a state structure diagram of the ventilation system provided by the present invention when the water level drops during the drainage process.

[0028] Figure 7The figure shows the state structure diagram when the ventilation system provided by the present invention reaches the third liquid level during the drainage process.

[0029] Figure 8 The figure shows the state structure diagram when the ventilation system provided by the present invention is completely emptied during the drainage process. Detailed implementation manners

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0033] [First Embodiment] As Figure 1-2 The figure shows a biological retention facility non-powered soil ventilation system provided by the first embodiment of the present invention, which includes a water storage module 100 and a ventilation module 200 that are arranged inside the soil layer and are interconnected through a communication pipe 300. As Figure 2 shown, in this embodiment, the soil layer includes an original soil layer 500 and a backfill soil layer 400, and the water storage module 100 and the ventilation module 200 are arranged inside the backfill soil layer 400.

[0034] In this embodiment, the water storage module 100 is in internal communication with the soil layer to receive rainwater in the soil layer and provide aeration to the soil layer. It should be noted that the function of the water storage module 100 in this solution is to assist the normal operation of the soil ventilation system, and its shape and type do not fall within the protection scope of this application. Therefore, the shape of the water storage module 100 does not necessarily need to be set as the shape shown in Figure 1-2 . It can also be set to cross-sectional shapes such as square, rectangular, and circular according to needs, as long as the water storage module 100 is set as a functional module capable of realizing underground water storage inside the soil. At the same time, the water storage module 100 can be provided with only one and directly communicate with the air permeation module 200 through the connecting pipe 300, or the water storage module 100 can be set as multiple interconnected ones and then communicate with the air permeation module 200 through the connecting pipe 300 to meet different water storage requirements inside the soil.

[0035] On one side of the air permeation module 200 in this embodiment, there is a drain opening 201 that can be selectively opened and closed. Through the drain opening, the rainwater inside the air permeation module 200 can be discharged, and external air can be sent into the air permeation module 200 and the water storage module 100 through the drain opening. The rainwater discharged from the air permeation module 200 can be discharged into the rainwater well 600 and then into the rainwater pipe network at the bottom of the road surface 700 through the rainwater well 600, or directly discharged into the rainwater pipe network at the bottom of the road surface 700.

[0036] The improvement of this embodiment compared with the prior art is that: inside the air permeation module 200, there are also a lifting support unit 200A and a drain door control unit 200B. The lifting support unit 200A can selectively provide support for the drain door control unit 200B according to the liquid level change inside the air permeation module 200, and the drain door control unit 200B can control the opening and closing of the drain opening 201 according to the liquid level change inside the air permeation module 200. Through the mutual cooperation of the lifting support unit 200A and the drain door control unit 200B, a set of ventilation cycle process for the soil can be realized following each rainfall process, and the ventilation frequency of the soil is more frequent than that of the traditional aeration mechanism, thereby further increasing the ventilation effect on the soil. At the same time, by using rainfall as the power to start the cycle of the entire soil ventilation system, no additional power support is required, no manual operation is needed, and the energy used is green, environmentally friendly, clean, and can be recycled sustainably.

[0037] Such as Figure 1As shown, the lifting support unit 200A in this embodiment includes a support float A1 that can rise and fall synchronously with the liquid level inside the ventilation module 200. One side of the support float A1 is connected to the support member A3 by rotating a transmission member A2 arranged inside the ventilation module 200. The support float A1 drives the support member A3 to rise and fall inside the ventilation module 200 through the transmission member A2. In order to further limit the movement trajectory of the support member A3, a guide rail is fixedly arranged inside the ventilation module 200, and the support member A3 is located inside the guide rail and can rise and fall relative to the guide rail.

[0038] This arrangement ensures that: when the rainwater in the ventilation module 200 does not reach the first liquid level initially, the lifting support unit 200A provides support for the exhaust door control unit 200B, and when the rainwater in the ventilation module 200 rises to the first liquid level, the lifting support unit 200A cancels the support for the exhaust door control unit 200B, and when the rainwater in the ventilation module 200 drops to the third liquid level, the lifting support unit 200A resumes the support for the exhaust door control unit 200B; and the first liquid level is higher than the third liquid level.

[0039] like Figure 1 As shown, the drain door control unit 200B in this embodiment includes a balancing member B1 rotatably arranged inside the ventilation module 200 through a hinge point B0, and the bottom of one side of the balancing member B1 can abut against the top of the support member A3. Under the abutting support of the support member A3, the balancing member B1 can be helped to maintain balance and not rotate. Preferably, an extension portion B5 abutting against the support member A3 is provided on the side of the balancing member B1 close to the support member A3, so as to increase the abutting area with the support member A3 as much as possible and thus maintain stable support. The other side of the balancing member B1 is fixedly connected to the drain door float B2, and the drain door float B2 is flexibly connected to the drain door B4 through the connecting member B3. The drain door B4 is adapted to the drain outlet 201, and through the rotation of the balancing member B1 inside the ventilation module 200, the drain door B4 can be pulled through the connecting member B3 to open the drain outlet 201.

[0040] In this embodiment, in order to facilitate the rotation of the balancing member B1 around the hinge point B0, the balancing member B1 is preferably made of a water-absorbing material so that: when the balancing member B1 does not absorb water, the sum of the masses of the balancing member and the extension portion located on the left side of the hinge point B0 is equal to the sum of the masses of the balancing member and the drain door float B2 located on the right side of the hinge point B0, and when the balancing member B1 rotates counterclockwise, its left side enters below the liquid level to absorb water and increase its weight, so that the balancing member B1 pulls the drain door B4 through the connecting member B3 and maintains the drain door float B2 at its current angle.

[0041] Such a setting makes it so that: when the rainwater inside the initial air-permeable module 200 has not reached the second liquid level, the drain gate control unit 200B does not rotate inside the air-permeable module 200 to control the closing of the drain opening 201. When the rainwater inside the air-permeable module 200 rises to the second liquid level (at this time, the second liquid level is higher than the first liquid level, and the support member A3 cancels the support effect on the balance member B1), the drain gate control unit 200B rotates to control the opening of the drain opening 201. And when the rainwater inside the air-permeable module 200 drops to the third liquid level, the drain gate control unit 200B rotates to its original position under the support of the lifting support unit 200A and relies on the self-weight of the drain gate B4 to control the closing of the drain opening 201; and the second liquid level is higher than the first liquid level.

[0042] [Second Embodiment] As Figures 3-8 shown is a control method for a non-powered soil ventilation system of a bioretention facility mentioned in the first embodiment provided by the second embodiment of the present invention, including the following steps: S1: As Figure 3 shown, when it starts to rain, the rainwater seeps into the inside of the water storage module 100 through the soil layer. The rainwater inside the water storage module 100 flows into the inside of the air-permeable module 200. The drain gate B4 closes the drain opening 201 due to its own gravity, and the rainwater cannot drain through the drain opening 201; S2: Since the closing of the drain opening 201 causes the liquid levels inside the water storage module 100 and the air-permeable module 200 to continuously rise with the increase in rainfall, the continuously rising liquid level inside the water storage module 100 squeezes the space position of the gas inside the water storage module 100, causing the gas inside the water storage module 100 to gradually move upward to the soil layer until it is discharged, completing the aeration of the soil layer; S3: While the liquid level is continuously rising, when the liquid level inside the water storage module 100 reaches the first liquid level, it will drive the support float A1 to rise synchronously. The support float A1 drives the support member A3 to descend synchronously along the guide rail through the transmission member A2. When the support member A3 descends along the guide rail and disengages from the contact with the drain gate control unit 200B, the support effect of the support member A3 on the drain gate control unit 200B disappears, as Figure 4 shown; S4: When the liquid level inside the air-permeable module 200 rises to the second liquid level, it drives the drain gate float B2 to rotate counterclockwise with the hinge point B0 as the center, as Figure 5 shown. The left side of the balance member B1 enters below the liquid level to absorb water and gain weight. The weights on the left and right sides of the balance member B1 are no longer balanced. The mass on the left side of the hinge point B0 is greater than the mass on the right side. At this time, even if the liquid level drops, the balance member B1 will drive the drain gate float B2 to maintain the current angle unchanged, as Figure 6 shown. The drain gate B4 is controlled to open by the drain gate float B2 through the connecting member B3. The water inside the interconnected water storage module 100 and air-permeable module 200 is discharged into the subsequent rainwater well or rainwater pipe network through the drain opening 201; S6: When the liquid level inside the air-permeable module 200 is lower than the nozzle of the drain pipe 201, external air enters the inside of the air-permeable module 200 from the drain pipe 201 and finally enters the inside of the water storage module 100; S7: Until the liquid level inside the air-permeable module 200 drops to the third liquid level, as Figure 7 shown. At this time, the liquid level inside the air-permeable module 200 is nearly emptied, and the support float A1 moves downward synchronously with the liquid level. The support float A1 drives the support member A3 to rise synchronously along the guide rail through the transmission member A2 until the support member A3 upwardly abuts against the left extension B5 of the balance member B1 and then continues to rise, thereby driving the balance member B1 and the drain door float B2 to rotate clockwise along the hinge point B0. At this time, the weights on the left and right sides of the balance member B1 are restored to balance, and the drain door B4 pulls the drain door float B2 under its own gravity to control the closing of the drain port 201, as Figure 8 shown.

[0043] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A non-powered soil aeration system for a bioretention facility, the system comprising a water storage module (100) and a ventilation module (200) which are arranged inside a soil layer and are interconnected, the water storage module (100) being connected to the inside of the soil layer so as to receive rainwater in the soil layer and provide aeration to the soil layer; a drain port (201) which can be selectively opened and closed is arranged on one side of the ventilation module (200), rainwater inside the ventilation module (200) can be discharged through the drain port, and external air can be sent into the ventilation module (200) and the water storage module (100) through the drain port; the characteristics are as follows: The ventilation module (200) is further provided with a lifting support unit (200A) and a discharge door control unit (200B) inside. The lifting support unit (200A) can selectively provide support for the discharge door control unit (200B) according to changes in the liquid level inside the ventilation module (200), and the discharge door control unit (200B) can control the opening and closing of the drain port (201) according to changes in the liquid level inside the ventilation module (200).

2. The unpowered soil aeration system for a bioretention facility according to claim 1, characterized in that: The lifting support unit (200A) comprises a support float (A1) capable of synchronously lifting and lowering with the liquid level inside the ventilation module (200); one side of the support float (A1) is connected to a support member (A3) by rotating a transmission member (A2) disposed inside the ventilation module (200); and the support float (A1) drives the support member (A3) to move up and down inside the ventilation module (200) via the transmission member (A2).

3. The unpowered soil aeration system for a bioretention facility according to claim 2, characterized in that: A guide rail is fixedly arranged inside the ventilation module (200), and the support member (A3) is located inside the guide rail and can move up and down relative to the guide rail.

4. The unpowered soil aeration system for a bioretention facility according to claim 2, characterized in that: The discharge door control unit (200B) comprises a balancing member (B1) rotatably arranged inside the ventilation module (200); the bottom of one side of the balancing member (B1) can abut against the top of the support member (A3); the other side of the balancing member (B1) is fixedly connected to a discharge door float (B2); the discharge door float (B2) is flexibly connected to the discharge door (B4) via a connecting member (B3); and the discharge door (B4) is adapted to the drain outlet (201).

5. The unpowered soil aeration system for a bioretention facility according to claim 4, characterized in that: The balancing piece (B1) is rotatably arranged inside the ventilation module (200) via a hinge point (B0), and the balancing piece (B1) is made of a water-absorbing material.

6. The unpowered soil aeration system for a bioretention facility according to claim 5, characterized in that: An extension portion (B5) abutting against the support member (A3) is provided on one side of the balancing member (B1) close to the support member (A3).

7. The unpowered soil aeration system for a bioretention facility according to claim 6, characterized in that: When the balancing member (B1) does not absorb water, the sum of the masses of the balancing member and the extension portion located on the left side of the hinge point (B0) is equal to the sum of the masses of the balancing member and the door float (B2) located on the right side of the hinge point (B0).

8. The unpowered soil aeration system for a bioretention facility according to claim 1, characterized in that: When rainwater in the ventilation module (200) does not initially reach a first liquid level, the lifting support unit (200A) provides support for the discharge door control unit (200B), and when rainwater in the ventilation module (200) rises to the first liquid level, the lifting support unit (200A) cancels support for the discharge door control unit (200B), and when rainwater in the ventilation module (200) drops to a third liquid level, the lifting support unit (200A) resumes support for the discharge door control unit (200B); and the first liquid level is higher than the third liquid level.

9. The unpowered soil aeration system for a bioretention facility according to claim 8, characterized in that: When the rainwater in the ventilation module (200) does not reach the second liquid level initially, the drain door control unit (200B) does not rotate inside the ventilation module (200) to control the drain outlet (201) to be closed; when the rainwater in the ventilation module (200) rises to the second liquid level, the drain door control unit (200B) rotates to control the drain outlet (201) to be opened; and when the rainwater in the ventilation module (200) drops to the third liquid level, the drain door control unit (200B) rotates to the original position under the support of the lifting support unit (200A) and controls the drain outlet (201) to be closed by relying on the deadweight of the drain door; and the second liquid level is higher than the first liquid level.

10. A control method for an unpowered soil aeration system of a bioretention facility according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: When rainfall begins, rainwater infiltrates into the water storage module (100) through the soil layer, and rainwater in the water storage module (100) flows into the air permeable module (200). The drainage door (B4) closes the drainage outlet (201) due to its own gravity, and rainwater cannot be drained through the drainage outlet (201); S2: As the drain port (201) is closed, the liquid level inside the water storage module (100) and the ventilation module (200) continues to rise as the rainfall increases. The liquid level inside the water storage module (100) continues to rise, occupying the space of the gas inside the water storage module (100), so that the gas inside the water storage module (100) gradually moves upward to the soil layer until it is discharged, thereby completing the aeration of the soil layer. S3: The continuous rise of the liquid level also drives the support float (A1) to rise synchronously, and the support float (A1) drives the support member (A3) to descend synchronously along the guide rail through the transmission member (A2); S4: when the liquid level inside the water storage module (100) reaches a first liquid level, the support member (A3) descends along the guide rail and is disengaged from the discharge door control unit (200B), and the support function of the support member (A3) on the discharge door control unit (200B) disappears; S5: When the liquid level inside the ventilation module (200) rises to a second liquid level, the discharge door float (B2) is driven to rotate counterclockwise with the hinge point (B0) as the center of the circle, and the left side of the balance member (B1) enters below the liquid level to absorb water and increase weight. The left and right counterweights of the balance member (B1) are no longer balanced, and the mass on the left side of the hinge point (B0) is greater than the mass on the right side. At this time, even if the liquid level drops, the balance member (B1) will drive the discharge door float (B2) to maintain the current angle unchanged, and the discharge door float (B2) controls the discharge door (B4) to open through the connecting member (B3), and the water inside the interconnected water storage module (100) and the ventilation module (200) is discharged into the subsequent rainwater well or rainwater pipe network through the drainage port (201); S6: When the liquid level inside the ventilation module (200) is lower than the outlet of the drainage pipe (201), external air enters the ventilation module (200) from the drainage pipe (201) and finally enters the water storage module (100); S7: until the liquid level inside the ventilation module (200) drops to the third liquid level, the support float (A1) moves downward synchronously with the liquid level, and the support float (A1) drives the support member (A3) to rise synchronously along the guide rail through the transmission member (A2), until the support member (A3) contacts the left extension (B5) of the balance member (B1) upwards and continues to rise, thereby driving the balance member (B1) and the discharge door float (B2) to rotate clockwise along the hinge point (B0), at which time the left and right counterweights of the balance member (B1) are balanced, and the discharge door (B4) pulls the discharge door float (B2) under the action of its own gravity to control the drain outlet (201) to close.

Images