Gas sampling device for measuring flux of greenhouse gas in water body

Abstract

The invention discloses a gas sampling device for measuring the flux of greenhouse gas in a water body. The gas sampling device comprises a floating table and a manual sampling chamber, the floating table comprises a floating body, a water seal tank and a flux ring, the floating body provides buoyancy, the water seal tank forms air-tight seal through water injection, and the flux ring is used for being matched with the automatic flux chamber. The floating body is provided with hollow holes, and water-gas interface substance exchange is achieved. The manual sampling chamber is of a bottomless columnar structure and comprises a barrel, a top cover, a gas sampling port and a gas pressure balance port, and the lower end of the manual sampling chamber can be inserted into the water seal tank to form gas seal. The gas sampling port is connected with sampling equipment or a laser spectrometer, and the gas pressure balance port maintains pressure balance. The floating table and the manual sampling chamber are designed in a modularized and separable mode, and after the manual sampling chamber is detached, the flux ring can be provided with an automatic flux chamber for measurement. The device is modularized and separable in design, flexible in multi-combination mode, suitable for various application scenes, compact in structure, convenient to carry and install and suitable for in-situ monitoring and research of water body greenhouse gas flux.

Description

Technical Field

[0001] The present invention relates to the technical field of greenhouse gas monitoring, and particularly to a gas sampling device for measuring the greenhouse gas flux in water bodies. Background Art

[0002] The release of greenhouse gases in water bodies (such as carbon dioxide, methane, and nitrous oxide) is an important source of global greenhouse gas emissions. Existing devices for measuring the greenhouse gas flux in water bodies are usually bulky and complex to operate, making them inconvenient for fieldwork. At the same time, traditional devices usually lack lightweight and modular designs and are difficult to adapt to complex field environments. Therefore, it is of great significance to develop a lightweight, flexible, modular, and multi-scenario suitable gas sampling device for water bodies.

[0003] It should be noted that the information disclosed in the above background art section is only for understanding the background of the present application, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0004] The main object of the present invention is to overcome the defects existing in the above background art, and to provide a gas sampling device for measuring the greenhouse gas flux in water bodies.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A gas sampling device for measuring the greenhouse gas flux in water bodies, comprising:

[0007] A floating platform, including a floating main body, a water seal groove, and a flux ring. The floating main body provides buoyancy. The water seal groove is an annular structure provided at the top of the floating main body, and forms a reliable airtight seal by injecting water. The flux ring is arranged inside the water seal groove and is used to adapt to an automatic flux chamber for measurement. The floating main body is provided with a hollow hole that penetrates up and down, and the hollow hole communicates with the flux ring, which can provide a channel between the water surface and the air to realize the material exchange at the water-air interface. A manual sampling chamber, which is a bottomless cylindrical structure, includes a hollow cylinder body, a top cover that closes the upper part of the cylinder body, a gas sampling port and a pressure balance port provided on the top cover. The lower end of the cylinder body can be adaptively inserted into the water seal groove and forms an airtight seal with the floating platform after the water seal groove is filled with water. The gas sampling port is used to connect a sampling device or a laser spectroscopic gas concentration analyzer, and the pressure balance port is used to maintain the pressure balance inside and outside the sampling chamber.

[0008] The floating platform and the manual sampling chamber are configured with a modular and separable design. When the manual sampling chamber is removed from the floating platform, an automatic flux chamber can be docked and installed through the flux ring for automatic flux measurement.

[0009] Further, the water seal groove is composed of two concentric circular rings with protrusions, and the height of the protrusions is 25 - 35 mm.

[0010] Further, the flux ring is a detachable structure, which is a circular ring with a protrusion. The height of the protrusion is 30 - 100 mm, the inner diameter is 200 - 210 mm, and the thickness is 5 - 10 mm.

[0011] Further, the height of the cylinder body of the manual sampling chamber is 100 mm - 300 mm.

[0012] Further, the water seal groove, the flux ring, and the cylinder body of the manual sampling chamber are made of acrylic material or PVC material.

[0013] Further, a sampling gas hose is detachably connected to the sampling gas port on the top cover of the manual sampling chamber, and the sampling gas hose is connected to a sampling syringe through a three - way valve with a Luer connector.

[0014] Further, a pressure balance tube is detachably connected to the pressure balance port on the top cover of the manual sampling chamber, and the length is not less than 1.5 meters.

[0015] Further, two portable handles are provided on the top of the manual sampling chamber.

[0016] Further, a gas mixing fan is arranged inside the top cover of the manual sampling chamber. The gas mixing fan is kept more than 30 mm away from the top cover and is used to fully mix the gas inside the manual sampling chamber.

[0017] Further, a battery box assembly is arranged inside the manual sampling chamber to supply power to the gas mixing fan.

[0018] The present invention has the following beneficial effects:

[0019] The present invention provides a gas sampling device for measuring the gas flux of water - body greenhouse gases. Its main technical advantages lie in its innovative modular design and versatility. The device mainly consists of a floating platform and a manual sampling chamber. The floating platform provides buoyancy through a floating main body and is equipped with a water seal groove and a flux ring, which can achieve reliable airtight sealing and at the same time support the connection of an automatic flux chamber and the material exchange at the water - air interface. The manual sampling chamber is a bottomless columnar structure, equipped with a sampling gas port, a pressure balance port, and an internally integrated gas mixing fan and battery box assembly. It can be quickly combined with or separated from the floating platform to form a flexible sampling system.

[0020] The innovative modular design of the gas sampling device of the present invention not only realizes the separability of the floating platform and the manual sampling chamber, but also supports multiple combination methods and usage scenarios. The floating platform can either be used alone with the flux ring for automatic flux measurement or be combined with the manual sampling chamber for needle sampling or laserThe spectrometer performs in-situ measurement. This diverse combination method greatly improves the flexibility of the device And applicability, enabling it to meet different monitoring requirements and the demands of complex field environments, showing extremely high portability and practicality in field operations.

[0021] In addition, the gas sampling device has a compact structure, convenient operation, and good airtightness, making it suitable for long-term field monitoring. The highly integrated design of the manual sampling chamber further simplifies the operation process.

[0022] In summary, through modular design, separable multi-combinations, and diverse usage methods, the present invention achieves high efficiency, flexibility, and convenience in measuring the water body greenhouse gas flux, providing an ideal solution for in-situ monitoring and research of the water body greenhouse gas flux.

[0023] Other beneficial effects in the embodiments of the present invention will be further described below. Brief Description of the Drawings

[0024] Figure 1A And Figure 1B Are respectively the three-dimensional structure diagram and the top view of the floating platform in the embodiments of the present invention.

[0025] Figure 2A And Figure 2B Are respectively the three-dimensional structure diagram and the lying view (viewed from the lower end opening of the manual sampling chamber inward) of the manual sampling chamber in the embodiments of the present invention.

[0026] Figure 3 Is the exploded structure diagram of the floating platform and the manual sampling chamber in the embodiments of the present invention.

[0027] Figure 4 Are the physical diagrams of two combination methods of the floating platform, the manual sampling chamber, and the detachable flux ring.

[0028] Figure 5 Are the physical diagrams of three application scenarios of the floating platform. Detailed Embodiments

[0029] The following provides a detailed description of the embodiments of the present invention. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0030] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, the connection can be for fixing or for coupling or communicating.

[0031] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of 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. Therefore, it should not be construed as a limitation to the present invention.

[0032] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0033] Referring to Figures 1A to 5 , an embodiment of the present invention provides a gas sampling device for measuring the greenhouse gas flux in water, including a floating platform and a manual sampling chamber; the floating platform includes a floating main body 1, a water seal groove 2 and a flux ring 3. The floating main body 1 provides buoyancy. The water seal groove 2 is an annular structure provided at the top of the floating main body 1, and a reliable airtight seal is formed by injecting water. The flux ring 3 is arranged inside the water seal groove 2 and is used to adapt to an automatic flux chamber for measurement. The floating main body 1 is provided with a hollow hole that penetrates up and down, and the hollow hole communicates with the flux ring 3, which can provide a channel between the water surface and the air to achieve the material exchange at the water-air interface. The manual sampling chamber is a bottomless columnar structure, including a hollow cylinder 4, a top cover 5 that closes the upper part of the cylinder 4, a gas sampling port 6 and a pressure balance port 7 provided on the top cover 5. The lower end of the cylinder 4 can be adaptively inserted into the water seal groove 2 and forms an airtight seal with the floating platform after the water seal groove 2 is filled with water. The gas sampling port 6 is used to connect a sampling device or a laser spectroscopy gas concentration analyzer, and the pressure balance port 7 is used to maintain the pressure balance inside and outside the sampling chamber. The floating platform and the manual sampling chamber are configured as a modular separable design. When the manual sampling chamber is removed from the floating platform, an automatic flux chamber can be docked and installed through the flux ring 3 for automatic flux measurement.

[0034] Due to the innovative modular design and separable structure, the gas sampling device of the present invention has remarkable flexibility and versatility. The separable design of the floating platform and the manual sampling chamber not only facilitates the carrying and installation of the device but also supports various combination methods and usage scenarios. The floating platform can be either individually paired with a flux ring for automatic flux determination or combined with the manual sampling chamber for in-situ determination through needle sampling or a laser spectrometer. Such diverse combination methods greatly improve the applicability and portability of the device, enabling it to meet different monitoring requirements and the demands of complex field environments. In addition, the modular design simplifies the maintenance and replacement processes of the device and reduces the usage cost. The floating platform has good airtightness and is suitable for long-term field monitoring, while the highly integrated design of the manual sampling chamber further enhances the operational convenience. Generally speaking, through modular design, separable multi-combinations, and diverse usage methods, the present invention achieves efficient, flexible, and convenient determination of water body greenhouse gas fluxes, providing an ideal solution for in-situ monitoring and research of water body greenhouse gas fluxes.

[0035] The floating main body 1 is made of low-density waterproof material, providing sufficient buoyancy and having good corrosion resistance, and can be deployed in freshwater or seawater environments. In a preferred embodiment, the water seal groove 2 is composed of two concentric raised rings, and the raised height is 25 - 35 mm. The flux ring 3 is a detachable structure, which is a raised ring, the raised height is 30 - 100 mm, the inner diameter is 200 - 210 mm, and the thickness is 5 - 10 mm. The height of the cylinder 4 of the manual sampling chamber is 100 mm - 300 mm. The water seal groove 2, the flux ring 3, and the cylinder 4 of the manual sampling chamber are made of acrylic material or PVC material.

[0036] Preferably, a sampling gas hose 12 is detachably connected to the gas sampling port 6 on the top cover 5 of the manual sampling chamber, and the sampling gas hose 12 is connected to a sampling syringe 13 through a three-way valve 11 with a Luer connector. Preferably, a barometric balance tube is detachably connected to the barometric balance port 7 on the top cover 5 of the manual sampling chamber, and the length is not less than 1.5 meters. Two portable handles 8 are also provided on the top of the manual sampling chamber.

[0037] In a preferred embodiment, a gas mixing fan 10 is provided inside the top cover 5 of the manual sampling chamber, and the gas mixing fan 10 is kept at a distance of more than 30 mm from the top cover 5 for fully mixing the gas inside the manual sampling chamber. A battery box assembly 9 is provided inside the manual sampling chamber to supply power to the gas mixing fan 10.

[0038] The following further describes specific embodiments of the present invention.

[0039] A gas sampling device for water body greenhouse gas flux determination includes a floating platform and a manual sampling chamber. AsFigure 1A , Figure 1B and Figure 3 As shown in Figure 1A , Figure 1B and Figure 3 , the floating platform includes a floating main body 1, a water seal tank 2 and a flux ring 3. The floating main body 1 is made of corrosion-resistant waterproof material and is used to provide long-term buoyancy for the device in the water body. The water seal tank 2 can form a reliable airtight seal by injecting water. The flux ring 3 is used to cooperate with the automatic flux chamber for measurement. As Figure 2A , Figure 2B and Figure 3 shown, the manual sampling chamber includes a cylinder body 4, a top plate 5, a gas sampling port 6, a pressure balance port 7, a portable handle 8, a battery box assembly 9, a gas mixing fan 10, a three-way valve 11 with a Luer connector, a gas sampling hose 12 and a gas sampling syringe 13. The gas sampling port 6 of the manual sampling chamber can be connected to a sampling needle through a Luer connector for sampling, or can be used in conjunction with a laser spectroscopy gas concentration analyzer. The pressure balance port 7 is used to maintain the pressure balance inside and outside the sampling chamber. The gas mixing fan 10 ensures the uniformity of the sampled gas, and the electricity required for its operation is provided by the battery box assembly 9. The portable handle 8 facilitates the movement and operation of the device. The structure of the present invention is compact and the operation is convenient. The modular design is convenient for carrying and installation, and is suitable for in-situ monitoring and research of water body greenhouse gas flux.

[0040] Specifically, the floating main body 1 is made of low-density waterproof material, has good corrosion resistance, can be deployed in fresh water or seawater environment, with a side length of not less than 450 mm, and can provide a buoyancy of not less than 20 kg. The water seal groove 2 is made of acrylic material, located at the top of the floating main body, and is composed of two concentric raised circles with a raised height of 30 mm. The inner diameter of the outer acrylic ring is not less than the outer diameter of the manual sampling chamber, and the outer diameter of the inner acrylic ring is not greater than the inner diameter of the manual sampling chamber. The manual sampling chamber can be inserted into it, and a reliable airtight seal can be formed after filling with water. The flux ring is a detachable structure made of acrylic material, which is a circular ring with a circular protrusion. The protrusion height is 30 - 100 mm, the inner diameter is 200 mm, and the outer diameter is 210 - 220 mm, and is used to adapt to common automatic flux chambers on the market. There are hollow holes in the floating platform with a diameter similar to the inner diameter of the flux ring. These holes can provide a channel between the water surface and the air, without affecting the material exchange at the water-gas interface, and dissolved gases can diffuse into the air according to Henry's law. The manual sampling chamber is a bottomless columnar structure made of PVC or acrylic material, with the upper top cover closed. Except for the gas sampling port and the air pressure balance port, the upper part can achieve effective airtightness. The height of the cylinder of the sampling chamber is determined according to the gas emission amount of the measured water surface, usually not less than 100 mm and not higher than 300 mm. The gas sampling port is located at the center of the top cover of the manual sampling chamber, and is detachably connected with a PVC gas sampling hose. The length of the gas sampling hose does not exceed 50 mm, and is connected to a gas sampling syringe through a three-way valve with a Luer connector. The solvent of the gas sampling syringe is 20 - 50 mL, which can be used for gas sampling. The air pressure balance port can be connected to an air pressure balance pipe, which is used to make the pressure inside and outside the sampling chamber consistent. The air pressure balance pipe is detachable, with a length of not less than 1.5 meters, which can meet the air pressure balance function while avoiding gas exchange inside and outside the device. Inside the inner side of the top cover of the manual sampling chamber, a gas mixing fan 10 with a power of 2 - 4 W is suspended. The gas mixing fan keeps a distance of more than 30 mm from the top cover, which is used to generate disturbance inside the sampling chamber to ensure that the gas is fully mixed, thereby improving the sampling accuracy. The battery box assembly 9 can install three 18650 batteries to provide 12V voltage, which can supply power for the gas mixing fan to work for not less than 10 hours. In addition, two portable handles are provided on the top of the manual sampling chamber for convenient carrying and handling. The floating platform can be combined with the manual sampling chamber or the automatic flux chamber for use to monitor the greenhouse gas concentration in real time.

[0041] Application examples:

[0042] Figure 4 The physical photos show two combination methods of the floating platform. On the left, the floating platform is used in combination with the manual sampling chamber, and on the right, the floating platform is installed with the flux ring. Figure 5Three application scenarios of the floating platform are shown in physical photos: on the left, the floating platform uses a manual sampling chamber and a syringe for needle sampling; in the middle, the floating platform uses a manual sampling chamber equipped with a laser spectrometer for in-situ determination; on the right, the floating platform uses a flux ring with an automatic flux chamber for in-situ determination.

[0043] (1) Preparation before flux measurement.

[0044] The device is used for two methods: manual gas sampling method and automatic flux measurement method. One of the measurement methods needs to be determined before the measurement, and the device is adjusted according to the method. If manual gas sampling is used, it is necessary to use a manual sampling chamber, install a barometric equilibrium tube at the barometric equilibrium port, and remove the flux ring of the floating platform at the same time. If the automatic flux measurement method is used, it is necessary to use an automatic flux chamber and a laser spectrometer, install a flux ring on the floating platform at the same time, and ensure good airtightness between the flux ring and the floating platform.

[0045] (2) Device deployment.

[0046] Before conducting the experiment, place the floating platform above the water surface to be measured. The water surface can be a fresh water area or a sea water area, including but not limited to rivers, lakes, oceans, etc. It should be ensured that the floating platform is placed horizontally to enable The water seal tank is above, and at the same time, the middle hole can realize the connection of water and gas, without affecting the mass transfer at the water-gas interface exchange, and dissolved gases can spontaneously diffuse into the air.

[0047] (3) Manual gas sampling.

[0048] Turn on the power of the gas mixing fan built into the manual sampling chamber, buckle the manual sampling chamber into the water seal groove of the floating platform and ensure that the edge is inserted into it. After filling the water seal groove (2) on the top of the floating platform with water, an effective water seal can be formed to reduce the entry of external gases into the sampling chamber, ensure airtightness, and record the time t. At the t + 60s moment, collect 30 ml of gas through a syringe with a Luer connector and inject it into a pre-evacuated gas sample bottle. Record the sample number and save it. Repeat the operation at the t + 60s moment at the t + 300s, t + 600s, t + 900s, and t + 1200s moments. Keep the samples away from light and bring them back to the laboratory to measure the concentration of the sampled gas (carbon dioxide CO 2 , methane CH 4 , or nitrous oxide N 2 O) through a gas chromatograph. According to the gas concentration and sampling time, calculate the concentration change rate Δc / Δt, where Δc represents the concentration change amount and Δt represents the time change amount. This change rate can be used to calculate the greenhouse gas exchange amount at the water-air interface.

[0049] (4) Automatic flux measurement.

[0050] Place the automatic flux chamber on the flux ring and ensure airtightness. Connect the inlet and outlet of the automatic flux chamber to the laser spectroscopy equipment that can measure the greenhouse gas concentration. By opening and closing the box of the automatic flux chamber, the real-time concentration can be directly measured and the concentration change rate Δc / Δt can be obtained. After the automatic flux chamber is closed, a sealed chamber is formed between the automatic flux chamber and the flux ring. At this time, the laser spectroscopy can measure the gas concentration in the chamber in real time and simultaneously obtain the change rate of the concentration over time. This change rate result can be used to calculate the exchange amount of greenhouse gases at the water-air interface.

[0051] (5) Flux calculation.

[0052] Calculate the concentration change rate Δc / Δt according to the gas concentration and sampling time. According to the concentration change rate Δc / Δt, the absolute air temperature T, the pressure P, the gas constant R, the volume V of the gas chamber (including the volume V 1 of the flux chamber and the volume V 2 above the water surface of the hollow hole of the floating platform), the area S of the hollow hole of the floating platform, and the relative molecular mass Mr, calculate the gas flux. The gas flux calculation formula is:

[0053]

[0054] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several alternatives or modifications can be made to these described embodiments, and these alternative or modified forms should all be regarded as belonging to the protection scope of the present invention. In the description of this specification, reference terms such as "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" are described The foregoing means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the protection scope of the patent application.

Claims

1. A gas sampling device for measuring greenhouse gas flux in water, characterized in that: include: The floating platform comprises a floating body, a water seal groove and a flux ring, wherein the floating body provides buoyancy, the water seal groove is an annular structure arranged on the top of the floating body, and forms a reliable airtight seal by water injection, and the flux ring is arranged inside the water seal groove, and is used to adapt to the automatic flux chamber for measurement; the floating body is provided with a hollow hole that passes through from top to bottom, and the hollow hole is communicated with the flux ring, and can provide a channel between the water surface and the air to realize the exchange of substances at the water-air interface; The manual sampling chamber is a bottomless columnar structure, comprising a hollow cylinder, a top cover that closes the upper part of the cylinder, and an air sampling port and an air pressure balance port arranged on the top cover; the lower end of the cylinder can be adaptively inserted into the water seal groove, and forms an airtight seal with the floating platform after the water seal groove is filled with water; the air sampling port is used to connect the sampling equipment or the laser spectrum gas concentration analyzer, and the air pressure balance port is used to maintain the pressure balance inside and outside the sampling chamber; The floating platform and the manual sampling chamber are configured into a modular detachable design. When the manual sampling chamber is removed from the floating platform, the automatic flux chamber can be docked and installed through the flux ring to perform automatic flux measurement.

2. The gas sampling device according to claim 1, characterized in that: The water seal groove is composed of two raised concentric rings, and the raised height is 25-35mm.

3. The gas sampling device according to claim 1, characterized in that: The flux ring is a detachable structure, which is a raised circular ring with a raised height of 30-100 mm, an inner diameter of 200-210 mm, and a thickness of 5-10 mm.

4. The gas sampling device according to claim 1, characterized in that: The height of the cylinder of the manual sampling chamber is 100mm-300mm.

5. The gas sampling device according to claim 1, characterized in that: The water seal groove, the flux ring and the barrel of the manual sampling chamber are made of acrylic material or PVC material.

6. The gas sampling device according to claim 1, characterized in that: The gas sampling port is detachably connected with a gas sampling hose on the top cover of the manual sampling chamber, and the gas sampling hose is connected to a gas sampling syringe through a three-way valve with a Luer connector.

7. The gas sampling device according to claim 1, characterized in that: The air pressure balance port is detachably connected to an air pressure balance tube on the top cover of the manual sampling chamber, and the length of the tube is not less than 1.5 meters.

8. The gas sampling device according to claim 1, characterized in that: Two portable handles are arranged on the top of the manual sampling chamber.

9. The gas sampling device according to claim 1, characterized in that: A gas mixing fan is arranged on the inner side of the top cover of the manual sampling chamber, and the gas mixing fan is kept at a distance of more than 30 mm from the top cover to fully mix the gas in the manual sampling chamber.

10. The gas sampling device according to claim 9, characterized in that: A battery box assembly is provided in the manual sampling chamber to supply power to the gas mixing fan.

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