Layered underground greenhouse gas collecting device for rice field

Abstract

The layered underground greenhouse gas collecting device comprises a plurality of sections of gas collecting units which are detachably connected, each section of gas collecting unit comprises an outer cylinder body, a waterproof breathable film is fixedly arranged on the outer cylinder body, a gas inlet is formed in the outer circumferential surface of the outer cylinder body in a penetrating mode, and a gas outlet is formed in the outer circumferential surface of the outer cylinder body. Two partition plates are horizontally arranged in the outer cylinder body at intervals, an inner cavity is formed between the two partition plates, an inner cylinder body with the two ends penetrating through the partition plates is arranged in the inner cavity, a gas production pipe communicated with the inner cavity of the outer cylinder body is arranged on the inner cylinder body, and the inner cylinder bodies of the multiple sections of gas production units are coaxially arranged and form a pipe penetrating channel. And all the gas production pipes penetrate out of the gas production unit at the uppermost end through the pipe penetrating channel. The device can be suitable for the waterflooding environment of the rice field, can isolate invasion of water in the rice field during gas collection, improves the detection accuracy, can simultaneously observe gas dispersion and concentration change of different soil depths in situ, and improves the detection efficiency.

Description

Technical Field

[0001] This utility model relates to the field of soil detection technology, specifically to a layered underground greenhouse gas collection device for paddy fields. Background Technology

[0002] Currently, greenhouse gas (such as carbon dioxide CO2, methane CH4, and nitrous oxide N2O) capture technologies and devices occupy an important position in environmental science research. Although many technologies have been used to collect greenhouse gases emitted from the soil surface into the atmosphere, technologies and devices for direct in-situ collection from within the soil remain limited. As one of the major sources of greenhouse gas emissions, the emission dynamics of soil are crucial for understanding global climate change.

[0003] Most existing greenhouse gas sampling devices are primarily designed for dryland conditions. They typically consist of a sampling tube with an air inlet and an extraction pipe connected to one end. In use, the sampling tube is buried underground, and samples are collected at specific points via the extraction pipe. Under these conditions, gas exchange between the soil and atmosphere is relatively direct, without the need for significant water management considerations. However, in flooded paddy field environments, moisture can seep into the sampling tube, interfering with the detection process. Furthermore, due to the structural limitations of the sampling tube, it can only detect gases at a fixed soil depth, and cannot simultaneously observe the dispersion and concentration changes of multiple gases at different soil depths, making detection less convenient. Utility Model Content

[0004] The purpose of this invention is to provide a layered underground greenhouse gas collection device for paddy fields, which is suitable for the flooded environment of paddy fields, can isolate the intrusion of paddy field water during gas collection, improve the accuracy of detection, and can simultaneously observe the gas dispersion and concentration changes at different soil depths in situ, thereby improving detection efficiency.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a layered underground greenhouse gas collection device for paddy fields, comprising several detachably connected gas collection units. Each gas collection unit includes an outer cylinder, on which a waterproof and breathable membrane is fixedly installed. An air inlet is provided through the outer circumference of the outer cylinder. Two partitions are horizontally spaced inside the outer cylinder, forming an inner cavity between the two partitions. An inner cylinder with both ends penetrating the partitions is provided inside the inner cavity. A gas collection pipe communicating with the inner cavity of the outer cylinder is provided on the inner cylinder. The inner cylinders of several gas collection units are coaxially arranged and form a through-pipe channel. All gas collection pipes extend through the through-pipe channel to the outermost gas collection unit.

[0006] A further improvement of this utility model is that the gas sampling pipe includes a connecting head that penetrates the inner cylinder wall and a gas pipe fixed on the connecting head.

[0007] A further improvement of this utility model is that at least two air inlets are evenly distributed along the circumferential direction on the outer circumferential surface of the outer cylinder.

[0008] A further improvement of this utility model is that two annular grooves are provided on the outer circumferential surface of the outer cylinder, the air inlet is located between the two annular grooves, a sealing ring is provided in the annular groove, and the upper and lower ends of the waterproof and breathable membrane are sealed and fixed in the annular groove by clamps.

[0009] A further improvement of this utility model is that the waterproof and breathable membrane is a tubular membrane.

[0010] A further improvement of this utility model is that the upper and lower ends of the outer cylinder are respectively provided with an outer retaining ring and an inner retaining ring, and the outer cylinders of two adjacent gas collection units are fixed by the cooperation of the outer retaining ring and the inner retaining ring.

[0011] A further improvement of this utility model is that the lower end of the gas extraction unit is provided with a cone.

[0012] A further improvement of this utility model is that a control valve is provided at one end of the gas sampling pipe.

[0013] A further improvement of this utility model is that the partition is snapped and fixed inside the outer cylinder, and the waterproof and breathable membrane is disposed inside the outer cylinder with its upper and lower ends snapped and sealed between the inner wall of the outer cylinder and the partition.

[0014] The beneficial effects of this utility model are as follows:

[0015] This invention is applicable to flooded paddy fields. By setting up a waterproof and breathable membrane, it can isolate the intrusion of paddy field water during gas collection, thereby improving the accuracy of detection. Furthermore, by setting up multiple detachable and connectable gas collection units, it can simultaneously observe the gas dispersion and concentration changes at different soil depths in situ, thereby improving detection efficiency.

[0016] This invention features an inner cylinder housed within the outer cylinder. A connecting head on the inner cylinder allows for individual gas sampling at the corresponding depth for each gas sampling unit. Furthermore, the inner cylinders of several gas sampling units are coaxially aligned, forming a through-pipe channel. This facilitates the routing of the gas sampling pipes for each unit, allowing the gas sampling pipes to be positioned inside the outer cylinder, simplifying installation during construction.

[0017] This utility model uses a clamp and a sealing ring to seal and fix the waterproof and breathable membrane. Setting the waterproof and breathable membrane on the outside of the outer cylinder can maximize the isolation of moisture and facilitate the installation and replacement of the waterproof and breathable membrane.

[0018] In this invention, at least two air inlets are evenly distributed along the circumferential direction on the outer circumferential surface of the outer cylinder. The multiple air inlets expand the air intake area and improve the gas exchange efficiency.

[0019] In this invention, the lower end of the gas extraction unit is provided with a cone to facilitate direct insertion into the soil. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural schematic diagram of the present invention.

[0021] Figure 2 This is a schematic cross-sectional view of the structure of this utility model.

[0022] Figure 3 This is a schematic diagram of the gas extraction unit structure of this utility model.

[0023] Figure 4 This is a three-dimensional structural schematic diagram of the present invention (the outer cylinder of one of the gas sampling units is not shown in the figure).

[0024] In the diagram, 1-gas extraction unit, 2-outer cylinder, 3-air inlet, 4-partition plate, 5-inner cylinder, 7-connector, 8-annular groove, 9-outer retaining ring, 10-inner retaining ring, 11-cone head. Detailed Implementation

[0025] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1: Combination Figures 1-2 It is known that a layered underground greenhouse gas collection device for paddy fields includes several detachably connected gas collection units 1. Each gas collection unit 1 includes an outer cylinder 2. A waterproof and breathable membrane is fixedly installed on the upper part of the outer cylinder 2. An air inlet 3 is provided through the outer circumference of the outer cylinder 2. Two partitions 4 are horizontally spaced inside the outer cylinder 2, forming an inner cavity between the two partitions 4. An inner cylinder 5 with both ends penetrating through the partitions is provided inside the inner cavity. A gas collection pipe is provided on the inner cylinder 5 and communicates with the inner cavity of the outer cylinder 2. The inner cylinders 5 of several gas collection units 1 are coaxially arranged and form a through-pipe channel. All gas collection pipes pass through the through-pipe channel to the outside of the uppermost gas collection unit 1.

[0027] The gas sampling pipe includes a connecting head 7 that penetrates the inner cylinder 5 and is installed on the cylinder wall, and a gas pipe fixed to the connecting head 7. Preferably, the gas pipe is a PE flexible hose. A control valve is provided at one end of the gas sampling pipe.

[0028] At least two air inlets 3 are evenly distributed along the circumferential direction on the outer circumferential surface of the outer cylinder 2. Preferably, the air inlets 3 are vertical strip-shaped air inlets.

[0029] Preferably, the outer cylinder 2 is a cylinder with a height of 10cm and a diameter of 5cm, and the material of the outer cylinder 2 is PVC with a thickness of 4mm. The inner cylinder 5 has a diameter of 1.5cm.

[0030] Two annular grooves 8 are provided on the outer circumferential surface of the outer cylinder 2. The air inlet 3 is located between the two annular grooves 8. A sealing ring is provided in the annular groove 8. The upper and lower ends of the waterproof and breathable membrane are sealed and fixed in the annular groove 8 by clamps.

[0031] The waterproof and breathable membrane is a tubular membrane. It is fitted over the outside of the outer cylinder 2. Preferably, the waterproof and breathable membrane is made of polytetrafluoroethylene (PTFE).

[0032] During installation, the waterproof and breathable membrane is first positioned within the annular groove. Then, the sealing ring is embedded into the annular groove 8 to initially seal the waterproof and breathable membrane. Finally, the sealing ring is further tightened and fixed using clamps (such as ring clamps). Preferably, each annular groove has two sealing rings, with the waterproof and breathable membrane positioned between the two sealing rings for better sealing performance.

[0033] The outer cylinder 2 is provided with an outer retaining ring 9 and an inner retaining ring 10 at its upper and lower ends, respectively. The outer cylinder 2 of two adjacent gas sampling units 1 are fixed by the cooperation of the outer retaining ring 9 and the inner retaining ring 10. The outer circumferential surface of the inner retaining ring 10 is engaged with the inner circumferential surface of the outer retaining ring 9.

[0034] Preferably, the lower end of the gas extraction unit 1 is provided with a cone head 11.

[0035] Example 2: This example is based on Example 1, with modifications to its structure. The modified technical solution is as follows:

[0036] The diameter of the partition 4 is matched with the inner diameter of the outer cylinder 2. The partition 4 is snapped and fixed inside the outer cylinder 2. The waterproof and breathable membrane is set inside the outer cylinder 2 and its upper and lower ends are snapped and sealed between the inner wall of the outer cylinder 2 and the partition 4.

[0037] Compared to Embodiment 1, this embodiment places the waterproof and breathable membrane located on the outside inside the outer cylinder, which can reduce the damage to the waterproof and breathable membrane caused by the external environment. Furthermore, it utilizes the original partition 4 and the inner wall of the outer cylinder 2 to clamp and seal both ends of the waterproof and breathable membrane, reducing the need for the installation of annular grooves and sealing rings, thus reducing the cost of the device.

[0038] The working principle of the layered underground greenhouse gas collection device for paddy fields provided by the utility model is as follows: In use, multiple gas collection units are fixed by engaging the outer clamping ring 9 and the inner clamping ring 8 according to the detection needs. The assembled device is buried in the detection pit, and then the original soil is backfilled so that the device is buried in the soil and in close contact with the surrounding soil. The gas collection pipe extends out of the soil surface. A vacuum pump and the gas collection pipe are used to evacuate the outer cylinder. When the vacuum reaches a certain level, the control valve isolates the gas collection pipe from the outside air. Due to the negative pressure inside the outer cylinder 2, the soil gas will automatically flow into the outer cylinder. After the outer cylinder 2 has been balanced for 5 to 20 minutes, the sampler is connected to the gas collection pipe, and the control valve is opened to extract the gas.

[0039] In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Any equivalent structural or procedural transformations made using the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A layered underground greenhouse gas collection device for rice fields, characterized by: The application relates to a gas collecting device, which comprises a plurality of detachably connected gas collecting units (1), each of which comprises an outer cylinder (2), the upper end of the outer cylinder (2) is fixedly provided with a waterproof and breathable film, the outer circumferential surface of the outer cylinder (2) is provided with an air inlet (3) penetrating through the outer circumferential surface, two partition plates (4) are horizontally and spacedly arranged in the outer cylinder (2), an inner cylinder (5) penetrating through the partition plates (4) is arranged in the inner cavity formed between the two partition plates (4), the inner cylinder (5) is provided with a gas collecting pipe which is in communication with the inner cavity of the outer cylinder (2), the inner cylinders (5) of the plurality of gas collecting units (1) are coaxially arranged and form a pipe penetrating channel, and all the gas collecting pipes are led out of the uppermost gas collecting unit (1) through the pipe penetrating channel.

2. The layered underground greenhouse gas collection device for rice field according to claim 1, wherein: The gas collecting pipe comprises a communicating head (7) penetrating through the cylinder wall of the inner cylinder (5) and a gas pipe fixed on the communicating head (7).

3. The layered underground greenhouse gas collection device for rice field according to claim 1, wherein: At least two air inlets (3) are equidistantly distributed on the outer circumferential surface of the outer cylinder (2) along the circumferential direction of the outer cylinder (2).

4. The layered underground greenhouse gas collection device for rice field according to claim 1 or 3, characterized in that: Two annular grooves (8) are arranged on the outer circumferential surface of the outer cylinder (2), the air inlets (3) are located between the two annular grooves (8), a sealing ring is arranged in the annular groove (8), and the upper end and the lower end of the waterproof and breathable film are sealingly fixed in the annular groove (8) through a clamp member.

5. The layered underground greenhouse gas collection apparatus for rice field according to claim 1, wherein: The waterproof and breathable film is a cylindrical film.

6. The layered underground greenhouse gas collection apparatus for rice field according to claim 1, wherein: The upper end and the lower end of the outer cylinder (2) are respectively provided with an outer clamp ring (9) and an inner clamp ring (10), and the outer cylinder (2) of the adjacent two gas collecting units (1) is fixedly clamped through cooperation of the outer clamp ring (9) and the inner clamp ring (10).

7. The layered underground greenhouse gas collection apparatus for rice field according to claim 1, wherein: The lower end of the lowermost gas collecting unit (1) is provided with a taper head (11).

8. The layered underground greenhouse gas collection apparatus for rice field according to claim 1, wherein: One end of the gas collecting pipe is provided with a control valve.

9. The layered underground greenhouse gas collection apparatus for rice field according to claim 1, wherein: The partition plate (4) is clamped and fixed in the outer cylinder (2), and the waterproof and breathable film is arranged in the outer cylinder (2) and is clamped and sealed between the inner wall of the outer cylinder (2) and the partition plate (4).

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