A full-automatic, multi-frequency monitoring water-gas interface greenhouse gas flux box

Abstract

The application discloses a kind of full-automatic, multi-frequency monitoring water-gas interface greenhouse gas's flux box, including multiple support columns, and each support column bottom is fixedly connected with counterweight, and counterweight is fixedly connected with buoy, and buoy is provided with through hole, and the through hole of buoy is fixedly connected with cylinder body;Cylinder body top is fixedly provided with annular groove, and annular groove movably clamps the annular convex of cover bottom.This application can automatically realize long time, multi-frequency monitoring of water-gas interface greenhouse gas flux.Compared with traditional single monitoring method, the device can reduce the error of greenhouse gas flux caused by destructive sampling in non-fixed point monitoring, and the consumption of time, manpower and material resources in multi-frequency monitoring process.

Description

Technical Field

[0001] This invention belongs to the field of water environment greenhouse gas monitoring and is a fully automatic, multi-frequency flux box for monitoring greenhouse gases at the water-air interface. Background Technology

[0002] Studies have shown that greenhouse gas emissions from aquatic ecosystems, such as oceans, lakes, reservoirs, ponds, and rivers, will further increase with global warming. Therefore, accurately and directly assessing carbon emissions from aquatic ecosystems is crucial. However, traditional devices for directly monitoring greenhouse gases in water, such as flux chambers, combined with portable greenhouse gas analyzers for cumulative single-time monitoring of greenhouse gases at the water-air interface, or periodic gas collection from flux chambers for laboratory analysis, cannot meet the requirements for monitoring flux variations over different time periods, such as diurnal and daily variations. Furthermore, destructive sampling at non-fixed locations increases errors in greenhouse gas flux measurements. In addition, frequent monitoring of greenhouse gas fluxes in water using traditional flux chambers is extremely resource-intensive. The errors in greenhouse gas flux measurements caused by destructive sampling at non-fixed locations in traditional single-time monitoring methods are also significant. Summary of the Invention

[0003] This invention solves the technical problem of time-consuming and labor-intensive methods for repeatedly monitoring greenhouse gas fluxes in water bodies using traditional flux boxes.

[0004] To solve the above problems, this application provides the following technical solution:

[0005] A fully automatic, multi-frequency flux box for monitoring greenhouse gases at the water-air interface includes multiple support columns. Each support column is fixedly connected to a counterweight at its bottom. The counterweight is fixedly connected to a float. The float has a through hole that is fixedly connected to the float body. A weather station is fixedly installed on the inner wall of the through hole. The top of the cylinder is fixedly provided with an annular groove, which movably engages with the annular protrusion at the bottom of the cover.

[0006] A water-blocking ring is fixedly connected to the inner wall of the annular groove.

[0007] The cover is also fixedly connected to a sampling tube, and a filter is fixedly installed at the air inlet of the sampling tube. The filter is installed in the inner cavity of the cylinder, and the air outlet of the sampling tube is fixedly connected to the air inlet of the gas analyzer.

[0008] The top of the cover is fixedly equipped with a controller, battery, water pump, and gas analyzer.

[0009] The signal output terminal of the controller is electrically connected to the push rod, the first fan, the second fan, the water pump, and the control terminal of the gas analyzer.

[0010] Both ends of the cover are symmetrically and fixedly connected to sliders. The outer side of the slider is provided with a sliding groove, and the side wall of each sliding groove is in sliding contact with each support column.

[0011] Push rods are fixedly connected to the two symmetrical sides at the bottom of the cover.

[0012] The bottom of the cover is fixedly connected to a first fan and a second fan.

[0013] The annular groove is provided with a connecting port, which is fixedly connected to a water injection pipe, and the water injection pipe is also fixedly provided with a water suction pipe.

[0014] Preferably, a weather station 603 is fixedly installed on the inner wall of the through hole 602 at a distance of 10-20cm from the water surface.

[0015] Preferably, the signal receiving end of the controller is electrically connected to the signal output end of the weather station.

[0016] A method for using a fully automated, multi-frequency flux box for monitoring greenhouse gases at the water-air interface includes the following steps: S1. Place the flux box on the water surface, start the first fan through the controller and drive the two push rods to open the cover. After the air in the flux box is released, control the push rods to close the cover. Then the water pump is started to continuously inject water into the annular groove at a high flow rate until the annular groove is full and overflow occurs; during the overflow, the water pump continuously replenishes water at a low flow rate. S2. Start the second fan briefly via the controller, then start the greenhouse gas analyzer. The gas analyzer extracts stable values ​​of greenhouse gas concentrations such as carbon dioxide (CO2) and methane (CH4) from the cylinder. After the measurement is completed, control the first fan and push rod to open the cover again after cycle N, and then close the cover. S3. After each interval N in step S, the controller repeats steps S1 to S2. When the greenhouse gas analyzer completes multiple monitoring sessions, the obtained data are the diurnal variation data of CO2 and CH4 concentrations.

[0017] Preferably, the venting time in step S1 is 5-6 minutes; Preferably, in step S1, the high flow rate is 60~70 ml / min, and the water overflows after continuous injection for 5~6 minutes; Preferably, in step S1, under overflow conditions, water is continuously replenished at a low flow rate of 7~8 ml / min to ensure that the gap between the annular groove and the annular protrusion is always in a completely sealed state. Preferably, in step S2, the controller starts the second fan for a short period of 3-4 minutes to ensure that the gas in the flux box is fully mixed; Preferably, in step S2, the greenhouse gas analyzer is started, and the gas analyzer extracts greenhouse gases from the cylinder to detect the concentrations of CO2 and CH4 in the 200 ml gas sample; Preferably, in step S2, the stable value of the delayed detection of CO2 and CH4 concentrations is 4 minutes after the start of detection, when the CO2 and CH4 concentrations measured by the greenhouse gas analyzer tend to stabilize, and the corresponding concentration value at this time is taken as the actual measured value. Preferably, in step S2, the period N is 3~4 hours.

[0018] Preferably, in step S3, the greenhouse gas analyzer performs 8 to 10 monitoring cycles. More preferably, in step S3, when the time interval of the controller is set to 3 hours / time, the data obtained by the greenhouse gas analyzer after 8 consecutive monitoring sessions are the daily variation data of CO2 and CH4 concentrations.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention enables fully automated monitoring of greenhouse gas fluxes at the water-air interface using the flux box method. Compared to traditional single-time monitoring methods, the device of this invention reduces errors in greenhouse gas fluxes caused by destructive sampling in non-fixed-point monitoring, as well as the consumption of time, manpower, and material resources during multiple monitoring sessions.

[0020] 2. The flux box of the present invention forms a sealed structure with a water tank through the annular protrusion 201 and the annular groove 301. When closed, the water in the water tank can completely seal the flux box without leakage, and when opened, it ensures that the water is in a natural state.

[0021] 3. This invention features a refined structure, stable operation, and small size, enabling the acquisition of accurate experimental data and making it suitable for field sampling. This invention has a wide range of applications, capable of obtaining greenhouse gas fluxes from various types of water bodies such as oceans, lakes, reservoirs, ponds, and rivers. Attached Figure Description

[0022] Figure 1 A schematic diagram of the overall structure of the flow meter with the lid open.

[0023] Figure 2 for Figure 1 A top-view structural diagram.

[0024] Figure 3 for Figure 2 A schematic diagram of the structure after disassembling cylinder 3, counterweight 601, and float 6.

[0025] Figure 4 for Figure 1A structural diagram showing the disassembled cylinder 3, annular groove 301, counterweight 601, and float 6.

[0026] Figure 5 for Figure 4 A structural diagram showing the disassembly of support column 1.

[0027] Figure 6 This is a structural schematic diagram of the pontoon 6 and the counterweight 601.

[0028] Figure label: Support column 1, cover 2, annular protrusion 201, cylinder 3, annular groove 301, water-blocking ring 302, push rod 4, slider 5, chute 501, float 6, counterweight 601, through hole 602, weather station 603, first fan 7, second fan 701, controller 8, battery 9, sampling tube 10, filter 1001, water suction pipe 11, water pump 12, gas analyzer 13, water injection pipe 14.

[0029] The model number selected in this patent is merely for illustrative purposes and is not intended to restrict the use of this particular model of instrument or material. Detailed Implementation

[0030] Example 1 like Figures 1-6 As shown, a fully automatic, multi-frequency monitoring flux box for greenhouse gases at the water-air interface includes multiple support columns 1. Each support column 1 has a counterweight 601 fixedly connected to its bottom. The counterweight 601 is fixedly connected to a float 6. The float 6 has a through hole 602. The through hole 602 of the float 6 is fixedly connected to the cylinder body 3. A weather station 603 is fixedly installed on the inner wall of the through hole 602. The top of the cylinder 3 is fixedly provided with an annular groove 301, which is movably engaged with the annular protrusion 201 at the bottom of the cover 2.

[0031] A water-blocking ring 302 is fixedly connected to the inner wall of the annular groove 301.

[0032] The cover 2 is also fixedly connected to the sampling tube 10. The air inlet of the sampling tube 10 is fixedly equipped with a filter 1001, which is set in the inner cavity of the cylinder 3. The air outlet of the sampling tube 10 is fixedly connected to the air inlet of the gas analyzer 13.

[0033] The top of the cover 2 is fixedly equipped with a controller 8, a battery 9, a water pump 12, and a gas analyzer 13.

[0034] The signal output terminal of the controller 8 is electrically connected to the control terminal of the push rod 4, the first fan 7, the second fan 701, the water pump 12, and the gas analyzer 13.

[0035] Both ends of the cover 2 are symmetrically and fixedly connected with sliders 5. The outer side of the slider 5 is provided with a sliding groove 501, and the side wall of each sliding groove 501 is in sliding contact with each support column 1.

[0036] Push rods 4 are fixedly connected to the two symmetrical sides at the bottom of the cover 2.

[0037] The bottom of the cover 2 is fixedly connected to the first fan 7 and the second fan 701.

[0038] The annular groove 301 is provided with a connecting port, which is fixedly connected to the water injection pipe 14. The water injection pipe 14 is also fixedly provided with a water suction pipe 11.

[0039] Preferably, a weather station 603 is fixedly installed on the inner wall of the through hole 602 at a distance of 10-20 cm from the water surface. The weather station 603 is powered by a battery 9.

[0040] The signal receiving end of controller 8 is electrically connected to the signal output end of weather station 603.

[0041] A method for using a fully automated, multi-frequency flux box for monitoring greenhouse gases at the water-air interface includes the following steps: S1. Place the flux box on the water surface, start the first fan 7 through the controller 8 and drive the two push rods 4 to open the cover 2. After the air in the flux box is released, control the push rods 4 to close the cover 2. Then, the water pump 12 is started to continuously inject water into the annular groove 301 at a high flow rate until the annular groove 301 is full and overflow occurs; during the overflow, the water pump 12 continuously replenishes water at a low flow rate. S2. Start the second fan 701 briefly through the controller 8, and then start the greenhouse gas analyzer 13. The gas analyzer 13 extracts greenhouse gases from the cylinder 3 to detect stable values ​​of CO2 and CH4 concentrations. After the measurement is completed, control the first fan 7 and push rod 4 to open the cover 2 again after cycle N, and then close the cover 2. S3. After each interval N in step S2, the controller 8 repeats steps S1 to S2. When the greenhouse gas analyzer 13 completes multiple monitoring, the obtained data are the diurnal variation data of CO2 and CH4 concentrations.

[0042] Preferably, the venting time in step S1 is 5 minutes; Preferably, in step S1, the high flow rate is 60 ml / min, and the water overflows after continuous injection for 5 minutes; Preferably, in step S1, under overflow conditions, water is continuously replenished at a low flow rate of 8 ml / min to ensure that the gap between the annular groove 301 and the annular protrusion 201 is always in a completely sealed state. Preferably, in step S2, the controller 8 starts the second fan 701 to run for a short time of 3 minutes to ensure that the gas in the flux box is fully mixed; Preferably, in step S2, the greenhouse gas analyzer 13 is started, and the gas analyzer 13 extracts greenhouse gas from the cylinder 3 to detect the concentrations of CO2 and CH4 in the 200 ml gas sample; Preferably, in step S2, the stable value of the delayed detection of CO2 and CH4 concentrations is 4 minutes after the start of detection, when the CO2 and CH4 concentrations measured by the greenhouse gas analyzer 13 tend to stabilize, and the corresponding concentration value at this time is taken as the actual measured value. Preferably, in step S2, the period N is 3 hours (the same as the time interval of controller 8 in step S3).

[0043] Preferably, in step S3, the greenhouse gas analyzer 13 performs multiple monitoring cycles, which is 8 times. More preferably, in step S3, when the time interval of the controller 8 is set to 3 hours / time, the data obtained by the greenhouse gas analyzer 13 after 8 consecutive monitoring sessions are the daily variation data of CO2 and CH4 concentrations.

[0044] Preferably, in step S1, the first fan 7 is used for gas exchange when the flux box is opened.

[0045] Preferably, in step S2, the second fan 701 is used to mix the greenhouse gas in the cylinder 3 after the flux box is closed.

[0046] The formula for calculating greenhouse gas fluxes is as follows:

[0047] In the formula, F Greenhouse gas flux (mg·m -2 ·h -1 ); Monitoring start time T The greenhouse gas concentration corresponding to 1 (h) is C 1 (ppm); monitoring end time T The greenhouse gas concentration corresponding to 2 (h) is C 2 (ppm); M The molar mass (g·mol) of greenhouse gases -1 ); V m The molar volume of greenhouse gases under standard conditions is 22.41 L·mol⁻¹. -1 Atmospheric pressure under monitoring conditions is P (kPa) and the air temperature close to the water surface are T (°C); H The height inside the flux box (m).

[0048] The diurnal CO2 and CH4 fluxes at the water-air interface are shown in Table 1.

[0049] M甲烷 = 16 g·mol -1 M 二氧化碳 = 44 g·mol -1 H = 0.5 m.

[0050] Table 1. Diurnal CO2 and CH4 fluxes at the water-air interface of an agricultural reservoir at 3-hour intervals.

[0051] Preferably, the support column 1 is used to mitigate the swaying effect of the stabilizing cylinder 3 when the cover 2 is raised or lowered. Preferably, the suction pipe 11 is used by the water pump 12 to draw river water. Preferably, the cylinder 3 has no cap at the bottom or top, and the cylinder 3 has a hollow structure; Preferably, the counterweight 601 is an iron block. Preferably, there are two support columns 1.

[0052] Preferably, the float 6 is a polyethylene foam tube.

[0053] Preferably, the battery 9 supplies power to the push rod 4, the first fan 7, the second fan 701, the controller 8, the water pump 12, and the gas analyzer 13.

[0054] Preferably, the push rod 4 is a telescopic rod, purchased from Dongguan Temuu Transmission Technology Co., Ltd., model TOMUU-U5, along with its related power supply and circuit.

[0055] Preferably, the first fan 7 is purchased from Shenzhen Youxin Electronics Technology Co., Ltd., model 4010s, along with its related power supply and circuitry.

[0056] Preferably, the second fan 701 is purchased from Shenzhen Defenglai Electronics Co., Ltd., specifically a DC 24V fan model and its related power supply and circuit.

[0057] Preferably, the timer power controller 8 is purchased from Shuyang County Zhuzhe Chiyi E-commerce Co., Ltd., model KG315T, along with its related power supply and circuit.

[0058] Preferably, the storage battery 9 is a P-HSE-2.2-12 model battery and its related power supply and circuit from Hebei Xunyan Technology Co., Ltd.

[0059] Preferably, the air filter 1001 is purchased from Xiamen Zanchengfeng Trading Co., Ltd., model ZFC100-04B / 06B.

[0060] Preferably, the water pump 12 is a C36451 model from Jinan Huimi Boke Technology Co., Ltd., along with its related power supply and circuitry. The water pump 12 has a built-in flow regulator. It is a 12V peristaltic pump.

[0061] Preferably, the gas analyzer 13 is a greenhouse gas analyzer, purchased from Beijing Century Chaoyang Technology Development Co., Ltd., model Picarro G2201-i, USA, along with its related power supply and circuitry; the gas analyzer 13 is equipped with a quantitative sampling pump.

[0062] Preferably, the weather station 603 is purchased from Shenzhen Huahanwei Technology Co., Ltd., specifically the TH20BL model and its related power supply and circuitry.

[0063] Weather station 603 is used to measure the temperature near the water surface and monitor the atmospheric pressure of the cylinder 3 under the environment. The weather station is fixedly attached to the inner wall of the through hole 602 of the float 6 at a position 10cm above the water surface.

[0064] The first fan 7 is used for gas exchange when the flux tank is opened, ensuring that the water in the flux tank is in a natural state.

[0065] The second fan 7-1 mixes the headspace gas after the flux box is closed.

[0066] Sampling tube 10 is used to collect the gas in cylinder 3 of the flux box.

[0067] The suction pipe 11, combined with the water pump 12, ensures that there is always water in the annular groove 301.

Claims

1. A fully automated, multi-frequency flux box for monitoring greenhouse gases at the water-air interface, comprising multiple support columns (1), characterized in that, Each of the support columns (1) is fixedly connected to a counterweight (601) at its bottom. The counterweight (601) is fixedly connected to a buoy (6). The buoy (6) is provided with a through hole (602). The through hole (602) of the buoy (6) is fixedly connected to the cylinder body (3). A weather station (603) is fixedly provided on the inner wall of the through hole (602). The top of the cylinder (3) is fixedly provided with an annular groove (301), which is movably engaged with the annular protrusion (201) at the bottom of the cover (2).

2. The fully automatic, multi-frequency flux chamber for monitoring greenhouse gases at the water-air interface according to claim 1, characterized in that, A water-blocking ring (302) is fixedly connected to the inner wall of the annular groove (301).

3. The fully automatic, multi-frequency flux monitoring chamber for greenhouse gases at the water-air interface according to claim 1, characterized in that, The cover (2) is also fixedly connected to a sampling tube (10). The inlet of the sampling tube (10) is fixedly equipped with a filter (1001). The filter (1001) is set in the inner cavity of the cylinder (3). The outlet of the sampling tube (10) is fixedly connected to the inlet of the gas analyzer (13).

4. The fully automatic, multi-frequency flux monitoring chamber for greenhouse gases at the water-air interface according to claim 1, characterized in that, The top of the cover (2) is fixedly equipped with a controller (8), a battery (9), a water pump (12), and a gas analyzer (13).

5. The fully automatic, multi-frequency flux monitoring chamber for greenhouse gases at the water-air interface according to claim 4, characterized in that, The signal output terminal of the controller (8) is electrically connected to the push rod (4), the first fan (7), the second fan (701), the water pump (12), and the control terminal of the gas analyzer (13).

6. The fully automatic, multi-frequency flux monitoring chamber for greenhouse gases at the water-air interface according to claim 1, characterized in that, The cover (2) has sliders (5) fixedly connected symmetrically at both ends. The sliders (5) have grooves (501) on the outside. The side wall of each groove (501) slides in contact with each support column (1).

7. The fully automatic, multi-frequency flux monitoring chamber for greenhouse gases at the water-air interface according to claim 1, characterized in that, Push rods (4) are fixedly connected to the two symmetrical sides of the bottom of the cover (2).

8. The fully automatic, multi-frequency flux monitoring chamber for greenhouse gases at the water-air interface according to claim 1, characterized in that, The bottom of the cover (2) is fixedly connected to a first fan (7) and a second fan (701).

9. The fully automatic, multi-frequency flux monitoring chamber for greenhouse gases at the water-air interface according to claim 1, characterized in that, The annular groove (301) is provided with a connecting port, which is fixedly connected to the water injection pipe (14), and the water injection pipe (14) is also fixedly provided with a water suction pipe (11).

10. A method for using a fully automated, multi-frequency flux monitoring chamber for greenhouse gases at the water-air interface as described in any one of claims 1-9, characterized in that... Includes the following steps: S1. Place the flux box on the water surface, start the first fan (7) through the controller (8) and drive the two push rods (4) to open the cover (2). After the air is released from the flux box, control the push rods (4) to close the cover (2). Then the water pump (12) is started to continuously inject water into the annular groove (301) at a high flow rate until the annular groove (301) is full and overflow occurs; when overflowing, the water pump (12) continuously replenishes water at a low flow rate. S2. Start the second fan (701) briefly through the controller (8), and then start the greenhouse gas analyzer (13). The gas analyzer (13) extracts and detects the stable values ​​of greenhouse gas concentrations such as carbon dioxide (CO2) and methane (CH4) from the cylinder (3). After the measurement is completed, control the first fan (7) and push rod (4) to open the cover (2) again after cycle N and then close the cover (2). S3, the controller (8) repeats steps S1 to S2 after each interval N in step S2; when the greenhouse gas analyzer (13) completes multiple monitoring, the obtained data is the diurnal variation data of CO2 and CH4 concentrations.

Images