Floatable dynamic box system for in-situ determination of greenhouse gas on water-gas interface and determination method

Abstract

The invention discloses a floatable dynamic box system for in-situ determination of greenhouse gas on a water-gas interface and a determination method, and relates to the technical field of water-gas interfaces, the floatable dynamic box system comprises a floatable sample accommodating gas chamber, an openable gas chamber top cover, a gas pump, a greenhouse gas measurement module and a data analysis processor. According to the method, a low-flow continuous gas extraction mode is adopted, equal-flow balance of gas is achieved through the gas inlet and the gas outlet, and pressure balance inside and outside the gas chamber is guaranteed. Compared with a traditional static box method and a vortex correlation method, flux data with higher time resolution can be obtained within shorter time, the application range is wide, manufacturing is easy, and the efficiency and accuracy of measuring the greenhouse gas flux of the water-gas interface are improved.

Description

Technical Field

[0001] This invention relates to the field of water-air interface technology, and in particular to a floating dynamic chamber system and method for in-situ measurement of greenhouse gases at the water-air interface. Background Technology

[0002] The water-air interface is a crucial channel for the release of greenhouse gases (such as carbon dioxide, methane, and nitrous oxide) into the atmosphere, and its flux changes exhibit significant spatiotemporal heterogeneity. To obtain the characteristics of greenhouse gas emissions from water bodies, existing studies employ measurement devices based on vacuum sampling, such as static chamber methods and semi-automatic chamber methods, to monitor gases at the water-air interface. However, these technologies still have the following shortcomings in practical applications: Firstly, some devices rely on closed or semi-closed sampling chambers, which can easily create pressure differences inside and outside the chamber during sampling due to vacuuming or gas accumulation, thus interfering with the natural diffusion process at the water-air interface and affecting the accuracy of flux measurement results. Secondly, some devices depend on manual intermittent sampling or offline analysis, making it difficult to achieve continuous, real-time monitoring of greenhouse gas concentration changes, resulting in low measurement efficiency and susceptibility to human operation and environmental disturbances. Furthermore, in aquatic environments, sampled gases are typically characterized by high humidity and a tendency to carry droplets and particulate impurities. Without effective filtration and protection measures, these factors can easily affect the gas pump and gas measurement module, thereby reducing the stability and reliability of the system operation.

[0003] This invention aims to provide a floating dynamic chamber system and method for in-situ measurement of greenhouse gases at the water-air interface, addressing the problems existing in the prior art. Through innovative design, the system integrates key components such as a floating sample-containing chamber, an openable / closable chamber top cover, an air pump, a greenhouse gas measurement module, and a data analysis processor. It provides a water-air interface greenhouse gas flux measurement system capable of achieving pressure balance and continuous dynamic sampling under in-situ water conditions, exhibiting excellent system stability. This system boasts advantages such as wide application range, simple construction, high measurement efficiency, and high accuracy, thereby improving the authenticity, continuity, and reliability of the measurement results. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems in the prior art and to provide a floating dynamic box system and measurement method for in-situ measurement of greenhouse gases at the water-air interface. Through dynamic flow sampling and pressure balance design, stable and continuous measurement of greenhouse gas flux at the water-air interface can be achieved.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A floating dynamic chamber system for in-situ measurement of greenhouse gases at the water-air interface includes: a floating sample-containing chamber, an openable and closable chamber top cover, an air pump, a greenhouse gas measurement module, and a data analysis processor.

[0007] The floating sample-containing air chamber is a cavity that runs vertically through the body. Its lower end is in contact with the water surface when in operation, forming a measurement space that covers the water-air interface.

[0008] The openable air chamber top cover covers the top of the floating sample-containing air chamber, and the connection between the two is sealed; the openable air chamber top cover is provided with an air inlet and an air outlet;

[0009] The air pump's inlet is connected to the air inlet of the openable air chamber top cover via an air passage, and is used to drive gas to be extracted from the floating sample containing air chamber.

[0010] The inlet of the greenhouse gas measurement module is connected to the outlet of the air pump via an air passage, and the outlet of the greenhouse gas measurement module is connected to the outlet of the floating sample containing air chamber. The greenhouse gas measurement module is used to perform online analysis of the extracted gas.

[0011] The data analysis processor is connected to the greenhouse gas measurement module and is used to receive and process measurement data.

[0012] The upper part of the floating sample-containing air chamber is provided with an annular groove, and the lower edge of the openable air chamber top cover is inserted into the annular groove; the annular groove can be injected with liquid to form a liquid seal.

[0013] The bottom of the floating sample holding chamber is provided with an annular air bladder to provide buoyancy so that the floating sample holding chamber floats stably on the water surface and keeps its bottom end in contact with the water surface.

[0014] A fan is suspended below the openable air chamber top cover to facilitate mixing of the gas inside the air chamber containing the floating sample.

[0015] A filter is installed in the air path between the air inlet of the openable air chamber top cover and the air inlet of the air pump to filter water vapor, droplets and particulate impurities in the gas.

[0016] The floating sample containment chamber is a transparent cylindrical cavity.

[0017] A method for in-situ determination of greenhouse gases at the water-air interface using the system described in this invention includes the following steps:

[0018] 1) Place the floating sample containing air chamber on the surface of the water body to be tested, so that it floats stably and covers the target water-air interface;

[0019] 2) The openable and closable air chamber top cover is sealed to the floating sample containing air chamber to form a relatively closed measurement space;

[0020] 3) Start the air pump to continuously extract the gas from the floating sample containment chamber and perform online analysis via the greenhouse gas measurement module;

[0021] 4) The concentration data output by the greenhouse gas measurement module is collected and analyzed in real time by the data analysis processor to realize continuous monitoring of greenhouse gas flux.

[0022] In step 2), a liquid seal is achieved between the liquid seal and the top cover of the openable and closable air chamber by injecting liquid into the annular groove above the floating sample containing air chamber.

[0023] After step 2) and before step 3), the fan located below the top cover of the openable air chamber is activated to facilitate the mixing of gases in the measurement space.

[0024] In step 3), the air pump's pumping flow rate is kept in balance with the gas flow rate entering the floating sample containment chamber to maintain a basically consistent pressure inside and outside the measurement space.

[0025] Compared with the prior art, the beneficial effects achieved by the technical solution of this invention are:

[0026] Compared to current technologies, this invention utilizes a floating structural design to stably deploy the gas chamber on the water surface. Employing a dynamic flow and pressure balance sampling method, it avoids interference from pressure differences caused by gas accumulation or extraction on the natural diffusion process at the water-gas interface. The system enables online, continuous monitoring of greenhouse gas concentrations, reducing uncertainties associated with manual operation. The device of this invention has a rational composition, moderate manufacturing cost, and is suitable for in-situ greenhouse gas flux measurement in various aquatic environments. It exhibits high stability and is suitable for widespread application. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a floating dynamic chamber system for measuring greenhouse gases at the water-air interface.

[0028] Figure 2 This is a schematic diagram of the three-dimensional structure of the air chamber that can hold a floating sample.

[0029] Figure 3 A three-dimensional structural diagram of a floating sample-containing air chamber and an openable / closable air chamber top cover.

[0030] Reference numerals: 1-Floating sample containment chamber, 2-Openable and closable chamber top cover, 3-Annular airbag, 4-Air pump, 5-Greenhouse gas measurement module, 6-Data analysis processor, 11-Outlet, outlet pipe 111, 12-Fan, 13-Inlet, inlet pipe 131, 14-Handle, 15-Filter, 16-Annular groove. Detailed Implementation

[0031] To make the technical problems, technical solutions and beneficial effects of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] Example 1

[0033] like Figures 1-3 As shown, the floating dynamic chamber system for measuring greenhouse gases at the water-air interface provided by the present invention mainly consists of a floating sample containing chamber 1, an openable and closable chamber top cover 2, an air pump 4, a greenhouse gas measurement module 5, and a data analysis processor 6.

[0034] The floating sample holding chamber 1 is a hollow cavity that runs vertically through the interior. In this embodiment, it is preferably a transparent cylindrical structure to facilitate observation of the internal state of the chamber. In its working state, the floating sample holding chamber 1 is positioned on the water surface, with its bottom in contact with the water surface, thus covering a certain area of ​​the water-air interface and forming a measurement space for greenhouse gas flux determination. An annular airbag 3 is provided at the bottom of the floating sample holding chamber 1. The annular airbag 3 is a sealed, flexible structure that provides buoyancy to the floating sample holding chamber 1, allowing it to float stably on the water surface. The buoyancy support of the annular airbag 3 ensures that the floating sample holding chamber 1 remains vertical on the water surface, with its bottom edge in contact with the water surface, thereby reducing the possibility of outside air entering the chamber from the water surface.

[0035] The openable and closable top cover 2 is positioned above the floating sample receiving chamber 1, covering the top of the floating sample receiving chamber 1 during measurement. The connection between the two is sealed to form a relatively independent measurement space. In a preferred embodiment, the upper part of the floating sample receiving chamber 1 is provided with an annular groove 16, and the lower edge of the openable and closable top cover 2 can be inserted into the annular groove 16. During measurement, an appropriate amount of pure water can be added to the annular groove 16 for liquid sealing to further reduce uncontrolled gas exchange between the inside and outside of the floating sample receiving chamber and improve measurement stability. It should be noted that the above sealing structure is only a preferred embodiment, and the present invention does not limit the specific sealing form. As long as it can effectively reduce irrelevant gas exchange between the inside and outside of the chamber during measurement, it should fall within the protection scope of the present invention.

[0036] A fan 12 is suspended below the openable air chamber top cover 2 to promote the mixing of gases inside the air chamber containing the floating sample. A handle 14 is provided on the top of the openable air chamber top cover 2 for easy operation.

[0037] The top of the openable air chamber cover 2 has two vents, serving as an air inlet 13 and an air outlet 11. The air inlet 13 is connected to the filter 15 via an air inlet pipe 131, and then to the air inlet of the air pump 4. The air outlet 11 is connected to the air outlet of the greenhouse gas measurement module 5 via an air outlet pipe 111, thus forming a continuous gas flow channel. The filter 15 is used to filter the gas entering the air pump, removing water vapor, droplets, and particulate impurities to reduce the impact of water vapor and impurities on system operation.

[0038] The air pump 4 drives the gas to circulate between the floating sample containment chamber 1 and the greenhouse gas measurement module 5, allowing the gas in the floating sample containment chamber to be continuously extracted and enter the greenhouse gas measurement module 5 for online analysis. By reasonably matching and controlling the gas flow rates at the air inlet 13 and the air outlet 11, the volume of gas entering and leaving the floating sample containment chamber 1 per unit time is kept basically consistent, thereby maintaining the internal pressure of the floating sample containment chamber 1 at a state close to the external atmospheric pressure, avoiding interference with the natural diffusion process at the water-air interface due to pressure changes.

[0039] The greenhouse gas measurement module 5 is used to perform real-time analysis of the collected gases. Modules suitable for greenhouse gases such as carbon dioxide, methane, and nitrous oxide can be selected according to actual needs. The greenhouse gas measurement module 5 is connected to the data analysis processor 6 via an integrated circuit or wireless communication. The data analysis processor 6 is used to collect, store, and analyze the measurement data in real time, thereby achieving continuous monitoring of greenhouse gas fluxes at the water-air interface.

[0040] The air inlet 13 and air outlet 11 located on the top of the openable air chamber cover 2 are connected to the air pump 4 and the greenhouse gas measurement module 5 via pipelines, forming a flow-through dynamic sampling gas path to maintain pressure balance inside and outside the air chamber 1 during measurement. Its working principle is explained below:

[0041] Air pump 4 continuously extracts gas from the floating sample containment chamber 1 through inlet 13 at a stable and controllable small flow rate. After online analysis by greenhouse gas measurement module 5, the gas is discharged or recirculated through outlet 11. By matching and controlling the gas volume flow rate of inlet 13 and outlet 11, the volume of gas entering and exiting the floating sample containment chamber 1 per unit time is kept approximately equal, thus maintaining a constant total gas volume within the chamber and avoiding significant positive or negative pressure. When changes in external environmental conditions (such as wind speed or temperature changes) or the operation of the air pump cause slight pressure fluctuations within the floating sample containment chamber 1, the dual-channel air path formed by inlet 13 and outlet 11 can adaptively adjust the gas exchange rate to quickly restore the pressure within the chamber to approximately the same level as the external atmospheric pressure, thereby achieving quasi-static pressure balance. By stabilizing the pressure within the floatable sample containment chamber 1 at a level close to ambient atmospheric pressure, the suction or inhibition effects caused by overpressure or negative pressure within the chamber can be effectively avoided, reducing interference with the natural diffusion process of greenhouse gases at the water-air interface, thereby improving the accuracy and reliability of flux measurement results. This pressure balancing mechanism, combined with the water seal structure formed by water injection into the annular trough 16, blocks uncontrolled gas exchange between the inside and outside of the chamber while allowing gas flow only through controlled gas paths formed by the inlet and outlet, thus maintaining a stable pressure environment within the floatable sample containment chamber 1 under dynamic sampling conditions.

[0042] Example 2

[0043] When measuring greenhouse gases such as nitrous oxide, methane, and carbon dioxide in actual processes, the following steps are included:

[0044] 1. First, place the floating sample containing air chamber 1 on the surface of the water body to be tested, so that it floats stably and covers the target water-air interface;

[0045] 2. The openable and closable air chamber top cover 2 is sealed and connected to the floating sample receiving air chamber 1 to form a measurement space; specifically, pure water is injected into the annular groove 16 at the top of the floating sample receiving air chamber 1 to achieve a liquid seal between it and the openable and closable air chamber top cover 2.

[0046] 3. Start fan 12 to promote gas mixing in the air chamber;

[0047] 4. Start the air pump 4 so that the gas in the floating sample containment chamber passes through the filter 15 and then enters the greenhouse gas measurement module 5 through the air pump 4 for online measurement.

[0048] 5. The measurement data is collected and processed in real time by the data analysis processor 6 to obtain the changing characteristics of greenhouse gas flux.

[0049] Through the above structure and working method, the present invention can achieve in-situ, continuous measurement of greenhouse gas flux without significantly disturbing the natural diffusion conditions at the water-air interface.

Claims

1. A floating dynamic chamber system for in-situ measurement of greenhouse gases at the water-air interface, characterized in that, include: The floating sample containment chamber (1), the openable and closable top cover of the chamber (2), the air pump (4), the greenhouse gas measurement module (5), and the data analysis processor (6) are included. The floating sample-containing air chamber (1) is a cavity that runs vertically through the body. Its lower end is in contact with the water surface in the working state, forming a measurement space that covers the water-air interface. The openable air chamber top cover (2) covers the top of the floating sample containing air chamber (1), and the connection between the two is sealed; the openable air chamber top cover (2) is provided with an air inlet (13) and an air outlet (11). The air pump (4) is connected to the air inlet (13) of the openable air chamber top cover (2) via an air passage, and is used to drive the gas to be drawn out from the floating sample containing air chamber (1). The inlet of the greenhouse gas measurement module (5) is connected to the outlet (8) of the air pump (4) through an air passage, and the outlet of the greenhouse gas measurement module (5) is connected to the outlet of the floating sample containing air chamber (1). The greenhouse gas measurement module is used to perform online analysis on the extracted gas. The data analysis processor (6) is connected to the greenhouse gas measurement module (5) and is used to receive and process measurement data.

2. The floating dynamic chamber system for in-situ measurement of greenhouse gases at the water-air interface as described in claim 1, characterized in that: The upper part of the floating sample containing air chamber (1) is provided with an annular groove (16), and the lower edge of the openable air chamber top cover (2) is inserted into the annular groove (16); the annular groove (16) is used to inject liquid to form a liquid seal.

3. The floating dynamic chamber system for in-situ measurement of greenhouse gases at the water-air interface as described in claim 1, characterized in that: The bottom of the floating sample holding chamber (1) is provided with an annular air bladder (3) to provide buoyancy so that the floating sample holding chamber (1) floats stably on the water surface and keeps its bottom end in contact with the water surface.

4. The floating dynamic chamber system for in-situ measurement of greenhouse gases at the water-air interface as described in claim 1, characterized in that: A fan (12) is suspended below the openable air chamber top cover (2) to facilitate the mixing of gases inside the floating sample containment air chamber (1).

5. The floating dynamic chamber system for in-situ measurement of greenhouse gases at the water-air interface as described in claim 1, characterized in that: A filter (15) is provided in the air passage between the air inlet (13) of the openable air chamber top cover (2) and the air inlet of the air pump (4).

6. The floating dynamic chamber system for in-situ measurement of greenhouse gases at the water-air interface as described in claim 1, characterized in that: The floating sample containment chamber (1) is a transparent cylindrical cavity.

7. A method for in-situ determination of greenhouse gases at the water-air interface using the system as described in any one of claims 1 to 6, characterized in that, Includes the following steps: 1) Place the floating sample containing air chamber (1) on the surface of the water body to be tested, so that it floats stably and covers the target water-air interface; 2) Seal the openable and closable air chamber top cover (2) with the floating sample containing air chamber (1) to form a relatively closed measurement space; 3) Start the air pump (4) to continuously extract the gas in the floating sample containment chamber (1) and perform online analysis through the greenhouse gas measurement module (5); 4) The concentration data output by the greenhouse gas measurement module (5) is collected and analyzed in real time by the data analysis processor (6) to realize continuous monitoring of greenhouse gas flux.

8. The determination method as described in claim 7, characterized in that: In step 2), a liquid seal is achieved between the liquid seal and the top cover (2) of the openable and closable air chamber by injecting liquid into the annular groove (16) at the top of the floating sample containing air chamber (1).

9. The determination method as described in claim 7, characterized in that: After step 2) and before step 3), the fan (12) located below the openable air chamber top cover (2) is activated to promote the mixing of gases in the measurement space.

10. The determination method as described in claim 7, characterized in that: In step 3), the air pump (4) maintains a balance with the gas flow rate entering the floating sample containment chamber (1).

Images