A buoy-type online measuring device and method for atmospheric and seawater carbon dioxide partial pressure

Abstract

The present invention discloses a buoy-type online measuring device and method for atmospheric and seawater carbon dioxide partial pressure. The device includes a bubbling carbon dioxide balance, a carbon dioxide measurement module and a standard gas storage unit. The device integrates the pipeline inside the carbon dioxide measurement module, and can automatically realize four different measurement modes of zero gas measurement, standard gas measurement, atmospheric carbon dioxide measurement and seawater carbon dioxide measurement through valve switching. Compared with traditional carbon dioxide measurement equipment, the present invention has self-calibration capability, and utilizes two-point calibration including zero gas and standard gas to ensure the accuracy of the instrument measurement results, while realizing the measurement of atmospheric carbon dioxide. In addition, the present invention carries out a floating design inside the bubbling carbon dioxide balance, and the floating design ensures that the measured water body is always at the same depth, reducing the uncertainty of seawater carbon dioxide caused by changes in measurement depth.

Description

Technical Field

[0001] The invention belongs to the technical field of seawater carbon dioxide measurement, and in particular relates to a buoy-type online determination device and method for atmospheric and seawater carbon dioxide partial pressures. Background Art

[0002] The in-situ measurement device of seawater carbon dioxide based on the buoy platform is an effective means to achieve high-time resolution observation of seawater carbon dioxide content. The currently available solutions for in-situ measurement of seawater carbon dioxide mainly include an online monitoring method of ocean carbon dioxide based on electrochemical sensing (CN111678966B), a precise carbon dioxide measurement system based on a rapid gas-liquid equilibrium device (CN117969444A), and a device and method for measuring dissolved carbon dioxide concentration in seawater at different depths by bubbling method (CN116359463A).

[0003] The methods and devices provided by the above three solutions have their own advantages and disadvantages. The first method and device mainly detect the carbon dioxide in seawater by detecting the carbonate concentration in seawater and the equilibrium relationship of the carbonate system. The entire device needs to calculate the carbon dioxide concentration by measuring four parameters: temperature, salinity, pH and carbonate concentration. Any problem in the measurement result of any parameter will affect the measurement of carbon dioxide in seawater, and it is difficult to ensure the accuracy of pH measurement. Therefore, it is difficult for the device to have a stable performance in a complex sea surface environment. The second device and method use a gas-liquid balance-non-dispersive infrared spectroscopy absorption method to measure the carbon dioxide concentration in seawater. The device mainly solves the efficiency problem of gas-liquid balance and the measurement error caused by temperature change during the process of seawater entering the gas-liquid balance. The structure of the device is relatively complex, and the use of water pumps and multiple constant temperature units consumes a lot of power, so it is not suitable for the complex working environment of the buoy platform and long-term observation. The third device uses the bubbling method to measure dissolved carbon dioxide, which is a feasible design solution. However, in the design, the calibration problem of the carbon dioxide measuring instrument is not taken into account, it is difficult to ensure the accuracy of the measurement results, and there is a lack of atmospheric carbon dioxide measurement. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problem in the prior art that it is difficult to continuously and accurately measure the atmospheric and seawater carbon dioxide partial pressure levels on a buoy platform for a long time, and to provide a buoy-type atmospheric and seawater carbon dioxide partial pressure online measurement device and method.

[0005] The specific technical solutions adopted by the present invention are as follows:

[0006] In the first aspect, the present invention provides a buoy-type online determination device for atmospheric and seawater carbon dioxide partial pressure, which includes a bubbling carbon dioxide balancer, a carbon dioxide measurement module and a standard gas storage unit; the carbon dioxide measurement module includes a CO2 absorbent module, an air circuit integrated block and an air circuit fixed module formed by sequentially connecting a filter, a desiccant module, a CO2 measuring instrument and an air pump; the CO2 absorbent module and the air circuit fixed module are connected to the air circuit integrated block through an air circuit; the air circuit integrated block has multiple switching valves built in, which are used to switch four working air circuits through controlled valve switching operations, namely, a zero gas measurement air circuit, a standard gas measurement air circuit, an atmospheric carbon dioxide measurement air circuit and a seawater carbon dioxide measurement air circuit; the zero gas measurement air circuit is sequentially connected to the CO2 absorbent module and the air circuit fixed module and then recirculated back to the CO2 absorbent module; the standard gas measurement air circuit is sequentially connected to the CO2 standard gas entry pipeline and the air circuit fixed module, and finally connected to the exhaust pipe for external discharge; The measuring gas circuit is connected to the air inlet pipeline and the gas circuit fixed module in sequence, and finally connected to the exhaust pipe for external discharge; the seawater carbon dioxide measuring gas circuit is connected to the seawater CO2 inlet pipeline, the gas circuit fixed module and the seawater CO2 outlet pipeline in sequence; the top of the buoying carbon dioxide balancer is used to be fixed on the buoy platform, and is equipped with a buoyant material block that can float on the water surface and a long and short tube air-blowing module vertically installed on the buoyant material block, the long and short tube air-blowing module includes a long tube, a short tube and a closed space at the top of the balancer that is connected to the top of the long tube and the top of the short tube at the same time, and the closed space at the top of the balancer is connected to the seawater CO2 inlet pipeline and the seawater CO2 outlet pipeline; when the seawater carbon dioxide measuring gas circuit is used as a working gas circuit, the gas in the closed space at the top of the balancer is pumped into the seawater CO2 inlet pipeline by the air pump, and is re-discharged from the seawater CO2 outlet pipeline and injected into the long tube for bubbling; a pressure reducing valve is arranged at the gas outlet of the standard gas storage unit, and the outlet of the pressure reducing valve is connected to the CO2 standard gas inlet pipeline.

[0007] As a preferred embodiment of the above-mentioned first aspect, a data acquisition and control module is provided in the carbon dioxide measurement module. The data acquisition and control module serves as a central control unit and is simultaneously connected to the CO2 measuring instrument, the switching valve in the gas circuit integrated block, and the air pump, and is used to control the switching valve to switch the working gas circuit and control the working state of the air pump, while realizing data acquisition and processing of the CO2 measuring instrument.

[0008] As a preferred embodiment of the first aspect, the switching valve in the gas circuit integrated block is implemented by using a plurality of three-way solenoid valves.

[0009] As a preferred embodiment of the above-mentioned first aspect, the bubbling carbon dioxide balancer includes a fixed module, a telescopic hose, a guide rod, a buoyant material block, a long and short tube air blowing module and an integrated air interface; the fixed module is used to be fixed on the buoy platform, the bottom of the guide rod is fixedly connected to the buoyant material block, and the top of the guide rod is inserted into the fixed module to form a sliding pair that limits the guide rod to only be able to move vertically; the long and short tube air blowing module is fixed on the buoyant material block and moves up and down with the buoyant material block along with the water surface fluctuations; the enclosed space at the top of the balancer is connected to the seawater CO2 inlet and the seawater CO2 outlet on the integrated air interface through two independent air paths in the telescopic hose, the seawater CO2 inlet on the integrated air interface is connected to the seawater CO2 inlet pipeline, and the seawater CO2 outlet on the integrated air interface is connected to the seawater CO2 outlet pipeline.

[0010] As a preferred embodiment of the above-mentioned first aspect, the integrated air interface is also provided with an air inlet and an exhaust gas outlet. The integrated air interface is connected to the carbon dioxide measurement module through a four-way gas pipe, the air inlet is connected to the air inlet pipe, and the exhaust gas outlet is connected to the exhaust gas pipe.

[0011] As a preferred embodiment of the above-mentioned first aspect, the integrated air interface is connected to the carbon dioxide measurement module through a four-way gas pipe, and the four-way gas pipes respectively transport the air input from the air inlet, the exhaust gas discharged from the exhaust pipe, the gas extracted from the enclosed space on the top of the balancer, and the gas output from the seawater CO2 outlet pipe through four independent gas paths.

[0012] As a preferred embodiment of the first aspect, the bubbling carbon dioxide balancer is made of copper.

[0013] As a preferred embodiment of the first aspect, the integrated air interface and the telescopic hose are intermediately connected via a two-way air pipe, and a joint position of the telescopic hose and the two-way air pipe is located at the fixing module.

[0014] As a preferred embodiment of the first aspect, a flange for protecting the tube body is installed at the bottom of the long tube of the long-short tube inflation module.

[0015] In a second aspect, the present invention provides a method for online determination of atmospheric and seawater carbon dioxide partial pressure using the buoy-type atmospheric and seawater carbon dioxide partial pressure online determination device according to any one of the schemes of the first aspect, comprising:

[0016] S1. Install the bubbling carbon dioxide balancer on the buoy platform, adjust the height so that the buoyant material block floats on the sea surface, and the long and short tube aeration modules penetrate vertically into the sea surface, so that seawater enters the top closed space of the balancer through the long tube and the short tube and partially fills the bottom space, forming a closed water-gas exchange space above the liquid surface;

[0017] S2, switching the zero gas measurement gas path to the working gas path, and then continuously circulating the gas inside the zero gas measurement gas path under the action of the air pump, completely removing CO2 through the CO2 absorbent module, and obtaining the first measurement data for the zero gas with a CO2 concentration of 0 by the CO2 measuring instrument for zero point calibration;

[0018] S3, switching the standard gas measurement gas path to the working gas path, and then continuously inputting the CO2 standard gas into the pipeline after decompressing the CO2 standard gas stored in the standard gas storage unit under the action of the air pump, and obtaining second measurement data for the CO2 standard gas through the CO2 measuring instrument for standard gas calibration;

[0019] S4, switching the atmospheric carbon dioxide measurement gas path to the working gas path, and then pumping air from the external atmosphere into the pipeline under the action of the air pump, and obtaining third measurement data for the external atmosphere through the CO2 measuring instrument for calculating the atmospheric carbon dioxide concentration;

[0020] S5. Switch the seawater carbon dioxide measuring gas path to the working gas path, and then pump the gas in the enclosed space on the top of the balancer into the seawater CO2 inlet pipeline under the action of the air pump, and then discharge it from the seawater CO2 outlet pipeline and inject it into the long tube for bubbling, so that CO2 circulates repeatedly in the seawater and the air above the liquid surface to reach equilibrium, and obtain fourth measurement data for the gas in the tube after equilibrium through the CO2 measuring instrument, which is used to calculate the seawater carbon dioxide concentration.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) The present invention integrates the internal pipelines of the carbon dioxide measurement module, and can automatically realize four different measurement modes through valve switching, namely zero gas measurement, standard gas measurement, atmospheric carbon dioxide measurement and seawater carbon dioxide measurement. Compared with traditional carbon dioxide measurement equipment, the present invention forms a self-calibration capability by adding a calibration gas path of the carbon dioxide measurement module, and ensures the accuracy of the instrument measurement results by using a two-point calibration containing zero gas and standard gas. At the same time, the present invention adds the determination of atmospheric carbon dioxide, which can subsequently realize the estimation of sea-air carbon dioxide flux.

[0023] 2) The present invention adopts a floating design for the interior of the bubbling carbon dioxide balancer, which ensures that the measured water body is always at the same depth, reducing the uncertainty of seawater carbon dioxide caused by changes in measurement depth.

[0024] 3) The present invention has carried out a highly integrated design for the gas passage inside the carbon dioxide measurement module, the internal structure is more concise, the overall volume is smaller, and it is suitable for installation on the buoy platform. It can increase the stability of the measurement system and enable it to cope with harsh and complex external environments such as strong winds and heavy rains. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of a buoy-type online measurement device for atmospheric and seawater carbon dioxide partial pressure;

[0026] Figure 2 This is the control circuit diagram inside the carbon dioxide measurement module;

[0027] Figure 3 This is the working principle diagram of the gas circuit inside the carbon dioxide measurement module;

[0028] Figure 4 It is a structural schematic diagram of a bubbling carbon dioxide balancer;

[0029] Figure 5 It is a schematic diagram of the structure of the integrated air interface;

[0030] The accompanying drawings are marked as follows: bubbling carbon dioxide balance 1, carbon dioxide measurement module 2, standard gas storage unit 3, standard gas single-core tube 4, four-way gas pipe 5, pressure reducing valve 6; the bubbling carbon dioxide balance 1 includes a fixed module 1-1, a telescopic hose 1-2, a guide rod 1-3, a buoyant material block 1-4, a long and short tube aeration module 1-5, a flange 1-6, an integrated air interface 1-7, and a two-way air pipe 1-8; the carbon dioxide measurement module 2 includes a zero gas measurement gas circuit A, a standard gas measurement gas circuit B, an atmospheric carbon dioxide measurement gas circuit C, a seawater carbon dioxide measurement gas circuit D, a CO2 measuring instrument 2-1, a CO2 absorbent module 2-2, an air inlet pipe 2-3, a desiccant module 2-4, a gas circuit integrated block 2-5, a data acquisition and control module 2-6, a seawater CO2 inlet pipe 2-7, an air pump 2-8, a seawater CO2 outlet pipe 2-9, a CO2 standard gas inlet pipe 2-10, an exhaust pipe 2-11 and a filter 2-12. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation mode of the present invention is described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. The technical features in each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0032] In the description of the present invention, it is to be understood that when an element is considered to be "connected" to another element, it may be directly connected to the other element or indirectly connected, that is, there are intermediate elements. On the contrary, when an element is said to be "directly" connected to another element, there are no intermediate elements.

[0033] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for the purpose of distinguishing descriptions, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0034] like Figure 1 As shown, in a preferred embodiment of the present invention, a buoy-type atmospheric and seawater carbon dioxide partial pressure online measuring device is provided, which includes a bubbling carbon dioxide balance 1, a carbon dioxide measurement module 2, a standard gas storage unit 3, a standard gas single-core tube 4, a four-way gas tube 5, a pressure reducing valve 6 and other components. The key to the device is that the pipeline is integrated inside the carbon dioxide measurement module 2, and the four different measurement modes of zero gas measurement, standard gas measurement, atmospheric carbon dioxide measurement and seawater carbon dioxide measurement can be automatically realized through valve switching. At the same time, the bubbling carbon dioxide balance 1 is also designed to float inside, ensuring that the measured water body is always at the same depth, reducing the uncertainty caused by the change of seawater carbon dioxide measurement depth. The remaining standard gas storage unit 3, standard gas single-core tube 4, four-way gas tube 5, and pressure reducing valve 6 are auxiliary structures of the bubbling carbon dioxide balance 1 and the carbon dioxide measurement module 2.

[0035] The specific structure and working principle of the bubbling carbon dioxide balancer 1 and the carbon dioxide measurement module 2 in the buoy-type atmospheric and seawater carbon dioxide partial pressure online determination device are introduced in detail below.

[0036] like Figure 2As shown, the gas circuit control principle inside the above-mentioned carbon dioxide measurement module 2 is demonstrated. The carbon dioxide measurement module 2 includes a CO2 measuring instrument 2-1, a CO2 absorbent module 2-2, a desiccant module 2-4, a gas circuit integrated block 2-5, an air pump 2-8 and a filter 2-12. The above-mentioned CO2 measuring instrument 2-1, the CO2 absorbent module 2-2, the desiccant module 2-4, the air pump 2-8 and the filter 2-12 are connected to the gas circuit integrated block 2-5 through the gas circuit, but the specific different modules are reused on different gas circuits but the connection methods are different. The specific gas circuit is integrated and automatically controlled by the gas circuit integrated block 2-5. The gas circuit integrated block 2-5 has multiple switching valves built in. These switching valves can be switched through controlled valve switching operations to form four working gas circuits, namely zero gas measurement gas circuit A, standard gas measurement gas circuit B, atmospheric carbon dioxide measurement gas circuit C and seawater carbon dioxide measurement gas circuit D. However, it should be noted that the zero gas measurement gas path A, the standard gas measurement gas path B, the atmospheric carbon dioxide measurement gas path C, and the seawater carbon dioxide measurement gas path D do not exist at the same time. Under different measurement conditions, generally only one of the zero gas measurement gas path A, the standard gas measurement gas path B, the atmospheric carbon dioxide measurement gas path C, and the seawater carbon dioxide measurement gas path D exists, and this existing gas path is regarded as the current working gas path. In the four different working gas paths, the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, and the air pump 2-8 are connected in sequence, which can constitute a gas path fixed module whose connection mode does not change with the switching of the working gas path, but the connection mode of the CO2 absorbent module 2-2 in different working gas paths is different.

[0037] Combine the following Figure 2 , the specific forms of the zero gas measurement gas circuit A, the standard gas measurement gas circuit B, the atmospheric carbon dioxide measurement gas circuit C, and the seawater carbon dioxide measurement gas circuit D are introduced. In the embodiment of the present invention, the switching valve in the gas circuit integrated block 2-5 is implemented by 6 three-way solenoid valves V1~V6. The gas circuit working principle based on these 6 three-way solenoid valves is as follows Figure 3 Of course, this is only a preferred exemplary approach, and other valve switching methods may be considered in other embodiments, and this is not limited.

[0038] The zero gas measurement gas circuit A in the present invention is connected in sequence to the CO2 absorbent module 2-2, the filter 2-12, the desiccant module 2-4, the CO2 meter 2-1, and the air pump 2-8, and then circulates back to the CO2 absorbent module 2-2. The CO2 absorbent module 2-2 is filled with CO2 absorbent, and its composition is not limited as long as it can absorb CO2 in the gas. The filter 2-12 is used to filter the gas and remove impurities. The desiccant module 2-4 is filled with desiccant to absorb moisture in the gas. The CO2 meter 2-1 can be implemented by any device that can detect the CO2 concentration in the gas, but it should be miniaturized as much as possible to facilitate integration on the buoy platform.

[0039] It should be noted that, since the gas circuit of the present invention is switched and controlled by the gas circuit integrated block 2-5, the above zero gas measurement gas circuit actually flows through the gas circuit integrated block 2-5 at some nodes, but the gas circuit integrated block 2-5 only plays a role of conduction and has no other substantial role. Figure 2 As shown, in an embodiment of the present invention, the zero gas measurement gas circuit is a closed gas circuit, and the pipeline gas passes through the CO2 absorbent module 2-2, the gas circuit integrated block 2-5, the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, the air pump 2-8, the gas circuit integrated block 2-5, and enters the CO2 absorbent module 2-2 again. In the zero gas measurement gas circuit, the air pump 2-8 provides the power required for the circulation of the gas in the pipe. After running for a certain period of time, the small amount of CO2 in the pipeline gas is absorbed and the measurement data of zero gas, i.e., CO2 concentration of 0, can be obtained, which is used for zero point calibration of the carbon dioxide instrument. In an embodiment of the present invention, as Figure 3 As shown, when the zero gas measurement gas circuit is used as the working gas circuit, among the 6 three-way solenoid valves on the gas circuit integrated block 2-5, the three-way solenoid valve V1 is in the right position, the three-way solenoid valve V2 is in the right position, the three-way solenoid valve V5 is in the left position, the three-way solenoid valve V4 is in the right position, and the three-way solenoid valve V3 is in the right position, and the other valves remain in their original positions.

[0040] The standard gas measurement gas circuit B in the present invention sequentially connects the CO2 standard gas to enter the pipeline 2-10, the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, the air pump 2-8, and finally connects to the exhaust pipe 2-11 for external discharge.

[0041] It should also be noted that, since the gas circuit of the present invention is switched and controlled by the gas circuit integrated block 2-5, the above-mentioned standard gas measurement gas circuit actually flows through the gas circuit integrated block 2-5 at some nodes, but the gas circuit integrated block 2-5 only plays a role of conduction and has no other substantial role. Figure 2As shown, in the embodiment of the present invention, when measuring the carbon dioxide standard gas, the CO2 standard gas sequentially passes through the pressure reducing valve 6 to enter the CO2 standard gas inlet pipeline 2-10, and then sequentially passes through the gas path integrated block 2-5, the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, the air pump 2-8, the gas path integrated block 2-5, and finally is discharged from the exhaust pipe 2-11, and the measurement data of the CO2 standard gas can be obtained for the calibration of the carbon dioxide instrument. In the embodiment of the present invention, as Figure 3 As shown, when the standard gas measurement gas circuit is used as the working gas circuit, the three-way solenoid valve V5 on the gas circuit integrated block 2-5 is in the right position, and the three-way solenoid valve V4 is in the left position.

[0042] The atmospheric carbon dioxide measurement gas path C in the present invention is connected to the air inlet pipe 2-3, the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, the air pump 2-8 in sequence, and finally connected to the exhaust pipe 2-11 for external discharge.

[0043] It should also be noted that, since the gas circuit of the present invention is switched and controlled by the gas circuit integrated block 2-5, the above atmospheric carbon dioxide measurement gas circuit actually flows through the gas circuit integrated block 2-5 at some nodes, but the gas circuit integrated block 2-5 only plays a role of conduction and has no other substantial role. Figure 2 As shown, in the embodiment of the present invention, when measuring atmospheric carbon dioxide, the air input from the external atmosphere passes through the air inlet pipe 2-3, the gas circuit integrated block 2-5, the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, the air pump 2-8, the gas circuit integrated block 2-5, and finally discharged from the exhaust pipe 2-11. After running for a certain period of time to eliminate the residual gas in the pipe, the atmospheric carbon dioxide measurement data can be collected by the CO2 measuring instrument 2-1. In the embodiment of the present invention, as Figure 3 As shown, when the atmospheric carbon dioxide measurement gas circuit is used as the working gas circuit, the three-way solenoid valve V1 on the gas circuit integrated block 2-5 is in the left position, the three-way solenoid valve V2 is in the right position, the three-way solenoid valve V5 is in the left position, and the three-way solenoid valve V4 is in the left position.

[0044] The seawater carbon dioxide measuring gas circuit D in the present invention sequentially connects the seawater CO2 inlet pipeline 2-7, the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, the air pump 2-8 and the seawater CO2 outlet pipeline 2-9.

[0045] It should also be noted that, since the gas circuit of the present invention is switched and controlled by the gas circuit integrated block 2-5, the above-mentioned seawater carbon dioxide measurement gas circuit actually flows through the gas circuit integrated block 2-5 at some nodes, but the gas circuit integrated block 2-5 only plays a role of conduction and has no other substantial role. Figure 2As shown, in the embodiment of the present invention, when measuring the carbon dioxide in seawater, the air in the closed space at the top of the balancer in the bubbling carbon dioxide balancer 1, the seawater CO2 enters the pipeline 2-7, the gas circuit integrated block 2-5, the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, the air pump 2-8, the gas circuit integrated block 2-5, the seawater CO2 outlet pipeline 2-9 and then returns to the long tube of the bubbling carbon dioxide balancer 1, and the seawater is bubbled by the exhausted gas, so that the carbon dioxide repeatedly circulates in the seawater in the closed space at the top of the balancer and the air above the liquid surface to reach equilibrium, and then the seawater carbon dioxide measurement data can be collected by the CO2 measuring instrument 2-1. In the embodiment of the present invention, as Figure 3 As shown, when the seawater carbon dioxide measurement gas circuit is used as the working gas circuit, the three-way solenoid valve V6 on the gas circuit integrated block 2-5 is in the left position, the three-way solenoid valve V2 is in the left position, the three-way solenoid valve V5 is in the left position, the three-way solenoid valve V4 is in the right position, and the three-way solenoid valve V3 is in the left position.

[0046] The measurement process and sequence of the carbon dioxide measurement module 2 in the present invention are divided into four measurement processes in sequence, firstly zero gas measurement, secondly standard gas measurement, then atmospheric carbon dioxide measurement, and finally seawater carbon dioxide measurement, wherein zero gas measurement and standard gas measurement are both calibration measurements, and atmospheric carbon dioxide measurement and seawater carbon dioxide measurement are both sample measurements. Therefore, inside the carbon dioxide measurement module 2, the zero gas measurement gas circuit, the standard gas measurement gas circuit, the atmospheric carbon dioxide measurement gas circuit, and the seawater carbon dioxide measurement gas circuit need to be switched in sequence to complete a round of measurement, and continue the cycle in the next round of measurement.

[0047] In addition, the normal operation of the above-mentioned carbon dioxide measurement module 2 needs to be coordinated with the bubbling carbon dioxide balancer 1 and the standard gas storage unit 3 for auxiliary cooperation.

[0048] The top of the bubbling carbon dioxide balancer 1 is used to be fixed on the buoy platform, and is equipped with a buoyant material block 1-4 that can float on the water surface and a long and short tube aeration module 1-5 vertically installed on the buoyant material block 1-4. The long and short tube aeration module 1-5 includes a long tube, a short tube and a closed space at the top of the balancer, and the closed space at the top of the balancer is connected to the top of the long tube and the top of the short tube. Figure 2 As shown in the figure, the long and short tube air-inflating modules 1-5 form a structure similar to the letter H as a whole. The topmost part is the closed space at the top of the balancer, the left side is the long tube and the right side is the short tube. Figure 2The long and short dashed lines in the lower half of the long and short tube aeration module 1-5 represent the seawater area. The enclosed space at the top of the balancer actually plays the role of a water-gas exchange space, and both seawater and gas can enter the enclosed space at the top of the balancer through the long tube and the short tube. The enclosed space at the top of the balancer is a relatively closed space. The enclosed space at the top of the balancer is connected to the seawater CO2 inlet pipe 2-7 and the seawater CO2 outlet pipe 2-9 by setting an opening. Only the long tube, the short tube and the opening at the top of the entire space can enter and exit gas and seawater, but the other parts are closed. Based on the water-gas balance method, part of the seawater sample enters the enclosed space at the top of the balancer through the long tube and the short tube, and then the CO2 is exchanged between the seawater and the air inside the enclosed space at the top of the balancer by continuous circulation and aeration. When the gas-liquid equilibrium is reached, the CO2 partial pressure of the air in the enclosed space at the top of the balancer is equal to the CO2 partial pressure of the seawater. Therefore, the CO2 concentration in the air after equilibrium can be measured, and the CO2 partial pressure of the seawater can be obtained by conversion.

[0049] The purpose of setting the long and short tubes in the long and short tube aeration module 1-5 of the present invention is to facilitate the entry of seawater into the enclosed space at the top of the balancer, and the long tube provides the space required for aeration. When the seawater carbon dioxide measurement gas path is used as the working gas path, the gas in the enclosed space at the top of the balancer is pumped into the seawater CO2 inlet pipe 2-7 by the air pump 2-8, and is re-discharged from the seawater CO2 outlet pipe 2-9 and injected into the long tube for bubbling. In order to ensure sufficient gas exchange, the enclosed space at the top of the scale can be evacuated above the short tube, and the gas is pumped into the seawater CO2 inlet pipe 2-7 by the air pump 2-8, and then returns to the long tube for bubbling to avoid short circuit.

[0050] In addition, the CO2 standard gas of the present invention can be stored in the standard gas storage unit 3 in the form of high-pressure gas, and the standard gas storage unit 3 can be in the form of a gas cylinder. A pressure reducing valve 6 is provided at the gas outlet of the standard gas storage unit 3, and the outlet of the pressure reducing valve 6 is connected to the CO2 standard gas inlet pipeline 2-10. The connection between the pressure reducing valve 6 and the CO2 standard gas inlet pipeline 2-10 in the carbon dioxide measurement module 2 can be realized through a gas pipeline, which is called a standard gas single-core tube 4.

[0051] In addition, as mentioned above, each cycle measurement process of the carbon dioxide measurement module 2 needs to perform four measurement processes in sequence, first the zero gas measurement, then the standard gas measurement, then the atmospheric carbon dioxide measurement, and finally the seawater carbon dioxide measurement. In this cycle, the valve needs to be switched, and the necessary equipment and electrical components such as the CO2 measuring instrument 2-1 and the air pump 2-8 need to be controlled and data collected and processed. Therefore, the carbon dioxide measurement module 2 also needs to be provided with a data acquisition and control module 2-6. As a central control unit, the data acquisition and control module 2-6 is connected to the CO2 measuring instrument 2-1, the switching valve in the gas circuit integrated block 2-5, and the air pump 2-8 at the same time. On the one hand, it is used to control the switching valve to switch the working gas circuit, and on the other hand, it is used to control the working state of the air pump 2-8. At the same time, it is also necessary to collect and process data for the CO2 measuring instrument 2-1. Based on this approach, the air intake and air outlet conditions of each channel are controlled by the solenoid valve on the gas circuit integrated block 2-5. When a measurement branch is performed, the other measurement branches are kept closed by the solenoid valve. The working time of each gas circuit, the switch of the solenoid valve, the data collection and processing can be conveniently adjusted and set flexibly through the data collection and control module 2-6. The specific control wiring method and data collection and processing flow of the data collection and control module 2-6 belong to the prior art and will not be repeated here.

[0052] like Figure 4 As shown, the specific structure of the bubbling carbon dioxide balancer 1 used in the embodiment of the present invention is demonstrated, which includes a fixed module 1-1, a telescopic hose 1-2, a guide rod 1-3, a buoyant material block 1-4, a long and short tube aeration module 1-5, a flange 1-6 and an integrated air interface 1-7.

[0053] The fixed module 1-1 is provided with a mechanism that can cooperate with the mounting member on the buoy platform, and is used to fix the bubbling carbon dioxide balancer 1 as a whole on the buoy platform. However, since the sea surface is volatile, a floating mechanism is specially designed in the present invention to ensure that the sampling and monitoring position of the seawater is at the same water depth. This floating mechanism is constructed by a guide rod 1-3 and a buoyant material block 1-4. The bottom of the guide rod 1-3 is fixedly connected to the buoyant material block 1-4, and a guide sleeve mechanism is provided in the fixed module 1-1. The top of the guide rod 1-3 penetrates the guide sleeve mechanism in the fixed module 1-1 to form a sliding pair that limits the guide rod 1-3 to only be able to move vertically. The buoyant material block 1-4 can be made of foam, airbags and other materials that can float on the sea surface. When the sea surface fluctuates, the buoyant material block 1-4 will move up and down synchronously, but because its top is fixed on the guide rod 1-3, the guide rod 1-3 is only allowed to rise and fall vertically, so the buoyant material block 1-4 can also move up and down accordingly. The long and short tube air-blowing module 1-5 is fixed on the buoyant material block 1-4 and moves up and down with the buoyant material block 1-4 as the water surface fluctuates. Therefore, even if the sea surface fluctuates, the relative position of the long and short tube air-blowing module 1-5 below the sea surface remains substantially unchanged. The enclosed space at the top of the balancer in the long and short tube air-blowing module 1-5 can be arranged inside the buoyant material block 1-4, and the enclosed space at the top of the balancer is connected to the integrated air interface 1-7 through two independent air paths in the telescopic hose 1-2. The telescopic hose 1-2 is arranged around the guide rod 1-3, and the telescopic hose 1-2 is telescopic and is used to provide a degree of freedom of deformation when the sea surface fluctuates. The two independent air paths in the telescopic hose 1-2 can be realized by setting two independent hoses, or by setting a hose with dual passages.

[0054] like Figure 5 As shown, the integrated air interface 1-7 in the present invention is a structural member that integrates multiple gas interfaces. In the embodiment of the present invention, the integrated air interface 1-7 integrates a total of four gas interfaces, namely, a seawater CO2 inlet, a seawater CO2 outlet, an air inlet and an exhaust gas outlet. These four gas interfaces can be connected to the carbon dioxide measurement module 2 through pipelines to supply various gases required for detection. Specifically, the closed space at the top of the balancer is connected to the seawater CO2 inlet and the seawater CO2 outlet on the integrated air interface 1-7 through two independent gas paths in the telescopic hose 1-2, the seawater CO2 inlet on the integrated air interface 1-7 is connected to the above-mentioned seawater CO2 inlet pipeline 2-7, and the seawater CO2 outlet on the integrated air interface 1-7 is connected to the above-mentioned seawater CO2 outlet pipeline 2-9. The air inlet and the exhaust gas outlet in the integrated air interface 1-7 are directly connected to the atmosphere. After the entire integrated air interface 1-7 is connected to the carbon dioxide measurement module 2 through a gas pipeline, the air inlet is connected to the above-mentioned air inlet pipeline 2-3, and the exhaust gas outlet is connected to the above-mentioned exhaust gas pipe 2-11.

[0055] It can be seen that four different gases need to be exchanged between the integrated air interface 1-7 and the carbon dioxide measurement module 2. Therefore, in the embodiment of the present invention, the integrated air interface 1-7 is connected to the carbon dioxide measurement module 2 through a four-way gas pipe 5, and the four-way gas pipe 5 uses four independent gas paths to respectively transport the air input from the above-mentioned air inlet, the exhaust gas discharged from the above-mentioned exhaust pipe 2-11, the gas extracted from the above-mentioned closed space on the top of the balancer, and the gas output from the above-mentioned seawater CO2 outlet pipe 2-9.

[0056] In addition, in the embodiment of the present invention, in order to prevent contamination caused by biological attachment, the main structural material of the bubbling carbon dioxide balancer 1 can be copper.

[0057] In addition, it should be noted that, in theory, the seawater CO2 inlet and the seawater CO2 outlet in the integrated air interface 1-7 can be directly connected to the telescopic hose 1-2, but considering that the telescopic hose 1-2 has a reciprocating pulling force during the sea surface fluctuation, in order to reduce the force of the telescopic hose 1-2 on the integrated air interface 1-7, the integrated air interface 1-7 and the telescopic hose 1-2 are connected in the middle through the two-way air pipe 1-8, rather than directly connected, and the joint position of the telescopic hose 1-2 and the two-way air pipe 1-8 is fixed at the fixed module 1-1. Therefore, the end of the two-way air pipe 1-8 is relatively fixed to the fixed module 1-1, which can offset the force generated by the telescopic hose 1-2.

[0058] In addition, in the embodiment of the present invention, a flange 1-6 can be installed at the bottom of the long tube of the long-short tube air-blowing module 1-5. The flange 1-6 can further increase the stability of the long-short tube air-blowing module 1-5 and maintain its center of gravity. At the same time, the flange 1-6 can also protect the long tube.

[0059] In the present invention, based on the above-mentioned buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device, a method for online measuring atmospheric and seawater carbon dioxide partial pressure is also provided, and its specific method includes the following steps S1 to S5. The specific methods of steps S1 to S5 are described in detail below.

[0060] S1. Install the bubbling carbon dioxide balancer 1 on a buoy platform, and make the buoyant material blocks 1-4 float on the sea surface by adjusting the height. The long and short tube aeration modules 1-5 penetrate vertically into the sea surface, so that seawater enters the enclosed space at the top of the balancer through the long tube and the short tube and partially fills the bottom space of the enclosed space at the top of the balancer, forming a closed water-gas exchange space above the liquid surface.

[0061] It should be noted that the specific depth of the long and short tube aeration modules 1-5 vertically penetrating into the sea surface needs to be adjusted according to actual measurement requirements, and there is no limitation on this. However, it should be ensured that the seawater can only partially fill the bottom space of the enclosed space at the top of the balancer, and will not completely fill the enclosed space at the top of the balancer.

[0062] S2. By the valve switching operation in the gas circuit integrated block 2-5, the zero gas measurement gas circuit is switched to the working gas circuit, and the other gas circuits are closed. Then, the gas inside the zero gas measurement gas circuit is continuously circulated under the action of the air pump 2-8, and the CO2 is completely removed by the CO2 absorbent module 2-2. The CO2 measuring instrument 2-1 obtains the first measurement data for the zero gas with a CO2 concentration of 0, which is used for zero point calibration.

[0063] S3. Through the valve switching operation in the above-mentioned gas circuit integrated block 2-5, the above-mentioned standard gas measurement gas circuit is switched to the working gas circuit, and the other gas circuits are closed. Then, under the action of the air pump 2-8, the CO2 standard gas stored in the standard gas storage unit 3 is decompressed and the CO2 standard gas is continuously input into the pipeline 2-10. It flows through the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, and the air pump 2-8 in turn and is discharged through the exhaust pipe 2-11. The second measurement data is obtained for the CO2 standard gas through the CO2 measuring instrument 2-1 for standard gas calibration.

[0064] S4. Through the valve switching operation in the above-mentioned gas circuit integrated block 2-5, the above-mentioned atmospheric carbon dioxide measurement gas circuit is switched to the working gas circuit, and the other gas circuits are closed. Then, under the action of the air pump 2-8, the external atmosphere is drawn into the air into the pipeline 2-3, and the air flows through the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, and the air pump 2-8 in sequence, and then discharged through the exhaust pipe 2-11. After running for a certain period of time to eliminate the residual gas in the pipe, the third measurement data can be obtained for the external atmosphere through the CO2 measuring instrument 2-1 for calculating the atmospheric carbon dioxide concentration.

[0065] S5. By the valve switching operation in the gas circuit integrated block 2-5, the seawater carbon dioxide measurement gas circuit is switched to the working gas circuit, and the other gas circuits are closed. Then, under the action of the air pump 2-8, the gas in the enclosed space on the top of the balancer is pumped into the seawater CO2 entering the pipeline 2-7, and flows through the filter 2-12, the desiccant module 2-4, the CO2 measuring instrument 2-1, and the air pump 2-8 in sequence, and then is discharged from the seawater CO2 outlet pipeline 2-9 and injected into the long tube for bubbling, so that CO2 is repeatedly circulated in the seawater and the air above the liquid surface to reach equilibrium, and the fourth measurement data is obtained by the CO2 measuring instrument 2-1 for the gas in the tube after equilibrium, which is used to calculate the seawater carbon dioxide concentration.

[0066] It should be noted that the above-mentioned first measurement data, second measurement data, third measurement data, and fourth measurement data are actually the measurement results obtained by the CO2 measuring instrument 2-1 in different modes for measuring the CO2 concentration of the gas in the gas pipeline, but their uses are different. The first two are calibration information, and the latter two correspond to the measurement values ​​of the atmospheric sample and the seawater sample, respectively. The CO2 measuring instrument 2-1 needs to first perform internal calibration using the calibration information, and then convert the actual sample measurement value according to the third measurement data and the fourth measurement data. During calibration, two-point calibration can be performed based on zero gas and standard gas. How to perform calibration and conversion specifically belongs to the basic operation of CO2 measurement and will not be repeated.

[0067] The above-described embodiments are only some preferred implementations of the present invention, but are not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device, characterized in that: It includes a bubbling carbon dioxide balancer, a carbon dioxide measurement module and a standard gas storage unit; the carbon dioxide measurement module includes a CO2 absorbent module, an air circuit integrated block and an air circuit fixed module which is connected in sequence by a filter, a desiccant module, a CO2 measuring instrument and an air pump; the CO2 absorbent module and the air circuit fixed module are connected to the air circuit integrated block through the air circuit; the air circuit integrated block has multiple switching valves built in, which are used to switch four working air circuits through controlled valve switching operations, namely, a zero gas measurement air circuit, a standard gas measurement air circuit, an atmospheric carbon dioxide measurement air circuit and a seawater carbon dioxide measurement air circuit; the zero gas measurement air circuit is connected to the CO2 absorbent module and the air circuit fixed module in sequence and then recirculates back to the CO2 absorbent module; the standard gas measurement air circuit is connected to the CO2 standard gas inlet pipeline and the air circuit fixed module in sequence, and finally connected to the exhaust pipe for external discharge; the atmospheric carbon dioxide measurement air circuit is connected to the air inlet pipeline, the air circuit fixed module in sequence After the module, it is finally connected to the exhaust pipe for external discharge; the seawater carbon dioxide measurement gas circuit is connected to the seawater CO2 inlet pipeline, the gas circuit fixing module and the seawater CO2 outlet pipeline in sequence; the top of the buoying carbon dioxide balancer is used to be fixed on the buoy platform, and is equipped with a buoyant material block that can float on the water surface and a long and short tube air-blowing module vertically installed on the buoyant material block, the long and short tube air-blowing module includes a long tube, a short tube and a closed space on the top of the balancer that is connected to the top of the long tube and the top of the short tube at the same time, and the closed space on the top of the balancer is connected through the seawater CO2 inlet pipeline and the seawater CO2 outlet pipeline; when the seawater carbon dioxide measurement gas circuit is used as the working gas circuit, the gas in the closed space on the top of the balancer is pumped into the seawater CO2 inlet pipeline by the air pump, and is discharged again from the seawater CO2 outlet pipeline and injected into the long tube for bubbling; a pressure reducing valve is arranged at the gas outlet of the standard gas storage unit, and the outlet of the pressure reducing valve is connected to the CO2 standard gas inlet pipeline.

2. The buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device according to claim 1, characterized in that: The carbon dioxide measurement module is provided with a data acquisition and control module. The data acquisition and control module serves as a central control unit and is simultaneously connected to the CO2 measuring instrument, the switching valve in the gas circuit integrated block, and the air pump. It is used to control the switching valve to switch the working gas circuit and control the working state of the air pump, while realizing data acquisition and processing of the CO2 measuring instrument.

3. The buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device according to claim 1, characterized in that: The switching valve in the gas circuit integrated block is realized by using multiple three-way solenoid valves.

4. The buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device according to claim 1, characterized in that: The bubbling carbon dioxide balancer includes a fixed module, a telescopic hose, a guide rod, a buoyant material block, a long and short tube air-blowing module and an integrated air interface; the fixed module is used to be fixed on a buoy platform, the bottom of the guide rod is fixedly connected to the buoyant material block, and the top of the guide rod penetrates into the fixed module to form a sliding pair that limits the guide rod to be able to move only vertically; the long and short tube air-blowing module is fixed on the buoyant material block and moves up and down with the buoyant material block along with the water surface fluctuations; the enclosed space at the top of the balancer is connected to the seawater CO2 inlet and the seawater CO2 outlet on the integrated air interface through two independent air paths in the telescopic hose, the seawater CO2 inlet on the integrated air interface is connected to the seawater CO2 inlet pipeline, and the seawater CO2 outlet on the integrated air interface is connected to the seawater CO2 outlet pipeline.

5. The buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device according to claim 4, characterized in that: The integrated air interface is also provided with an air inlet and an exhaust gas outlet. The integrated air interface is connected to the carbon dioxide measurement module via a four-way gas pipe. The air inlet is connected to the air inlet pipeline, and the exhaust gas outlet is connected to the exhaust gas pipe.

6. The buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device according to claim 4, characterized in that: The integrated air interface is connected to the carbon dioxide measurement module through a four-way gas pipe, and the four-way gas pipe transmits the air input from the air inlet, the exhaust gas discharged from the exhaust pipe, the gas extracted from the enclosed space on the top of the balancer, and the gas output from the seawater CO2 outlet pipe through four independent gas paths.

7. The buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device according to claim 1, characterized in that: The bubbling carbon dioxide balancer is made of copper.

8. The buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device according to claim 4, characterized in that: The integrated air interface and the telescopic hose are connected via two-way air pipes, and the joint position of the telescopic hose and the two-way air pipes is located at the fixing module.

9. The buoy type atmospheric and seawater carbon dioxide partial pressure online measuring device according to claim 1, characterized in that: A flange for protecting the pipe body is installed at the bottom of the long pipe of the long-short pipe air blowing module.

10. A method for online determination of atmospheric and seawater carbon dioxide partial pressure using the buoy-type atmospheric and seawater carbon dioxide partial pressure online determination device as claimed in any one of claims 1 to 9, characterized in that: include: S1. Install the bubbling carbon dioxide balancer on the buoy platform, adjust the height so that the buoyant material block floats on the sea surface, and the long and short tube aeration modules penetrate vertically into the sea surface, so that seawater enters the top closed space of the balancer through the long tube and the short tube and partially fills the bottom space, forming a closed water-gas exchange space above the liquid surface; S2, switching the zero gas measurement gas path to the working gas path, and then continuously circulating the gas inside the zero gas measurement gas path under the action of the air pump, completely removing CO2 through the CO2 absorbent module, and obtaining the first measurement data for the zero gas with a CO2 concentration of 0 by the CO2 measuring instrument for zero point calibration; S3, switching the standard gas measurement gas path to the working gas path, and then continuously inputting the CO2 standard gas into the pipeline after decompressing the CO2 standard gas stored in the standard gas storage unit under the action of the air pump, and obtaining second measurement data for the CO2 standard gas through the CO2 measuring instrument for standard gas calibration; S4, switching the atmospheric carbon dioxide measurement gas path to the working gas path, and then pumping air from the external atmosphere into the pipeline under the action of the air pump, and obtaining third measurement data for the external atmosphere through the CO2 measuring instrument for calculating the atmospheric carbon dioxide concentration; S5. Switch the seawater carbon dioxide measuring gas path to the working gas path, and then pump the gas in the enclosed space on the top of the balancer into the seawater CO2 inlet pipeline under the action of the air pump, and then discharge it from the seawater CO2 outlet pipeline and inject it into the long tube for bubbling, so that CO2 circulates repeatedly in the seawater and the air above the liquid surface to reach equilibrium, and obtain fourth measurement data for the gas in the tube after equilibrium through the CO2 measuring instrument, which is used to calculate the seawater carbon dioxide concentration.

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