Layered measurement system for greenhouse gas

Abstract

The utility model discloses a layered measurement system for greenhouse gas. The layered measurement system comprises a plurality of acquisition units arranged along the height direction of a sampling tower, a multi-port switching valve connected with the plurality of sampling units, and a measurement unit connected to the other end of the multi-port switching valve, the sampling unit comprises a sampling pump, a front dehumidifier and a rear dehumidifier which are respectively arranged at two ends of the sampling pump, and a flow meter connected with the rear dehumidifier; wherein the other end of the flow meter is connected with the multi-port switching valve, and the sampling pump is connected with a sampling port of the sampling tower. According to the utility model, the multi-port switching valve is connected with the acquisition units at different heights, and independent sampling of each sampling unit is realized through switching of the valve ports, so that the influence of gas mixing on the measurement accuracy is avoided. The gas path of the whole sampling system is switched by using the multi-port switching valve, so that the conditions that the traditional measuring system re-uses a separation electromagnetic valve, the pipeline is complex and easy to damage and is not easy to overhaul are avoided.

Description

Technical Field

[0001] The utility model relates to the field of greenhouse gas measurement, in particular to a greenhouse gas stratification measurement system. Background Art

[0002] Cities are concentrated areas of human activities. In the past, urban air pollution monitoring was mainly targeted at the surface, but it was affected by the emission type and emission intensity of regional pollution sources, atmospheric transport and turbulence, causing the atmosphere to show concentration fluctuations in the vertical direction. By expanding the three-dimensional monitoring in the height direction, monitoring the profiles of greenhouse gases (CO2, CH4, etc.) at different heights, combining the determination of urban pollution source spectrum, using the tracing of pollutant species and species ratios, and using the positive definite matrix factor decomposition model, the source analysis of urban greenhouse gases can be achieved.

[0003] Although there are airships and drone platforms that can achieve altitude measurements, these methods cannot achieve continuous monitoring and are difficult to meet actual needs. Although some researchers have conducted some high-tower monitoring, there are disadvantages in that practical applications require convenient operation and maintenance, low cost, stability and reliability. The sampling pipelines are complex, the failure rate is high, and it is not conducive to inspection and maintenance. Utility Model Content

[0004] The purpose of the utility model is to provide a greenhouse gas stratification measurement system to solve the problems raised in the above background technology.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A greenhouse gas stratified measurement system comprises a plurality of collection units arranged along the height direction of a sampling tower, a multi-port switching valve connecting the plurality of sampling units, and a measurement unit connected to the other end of the multi-port switching valve; the sampling unit comprises a sampling pump, a front dehumidifier and a rear dehumidifier respectively arranged at both ends of the sampling pump, and a flow meter connected to the rear dehumidifier; wherein the other end of the flow meter is connected to the multi-port switching valve, and the sampling pump is connected to the sampling port of the sampling tower.

[0007] Furthermore: it also includes a calibration unit connected to the multi-port switching valve, and the calibration unit includes three standard gas pipes with different concentrations.

[0008] Furthermore: the multi-port switching valve includes an air inlet valve port matching the number of flow meters, an air outlet valve port connected to the measuring unit, and a calibration valve port connected to three calibration gas pipes one by one.

[0009] Further: the sampling unit also includes a filter connected between the post-dehumidifier and the multi-port switching valve.

[0010] Furthermore: the sampling unit also includes a sampling tube connected between the pre-dehumidifier and the sampling port.

[0011] Furthermore: it also includes a flow pressure control unit arranged between the multi-port switching valve and the measuring unit.

[0012] Furthermore: the measuring unit includes a plurality of analyzers connected in parallel and a data acquisition and transmission module connected to the analyzers.

[0013] Further: the number of sampling units is at least two.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The multi-port switching valve in the utility model is connected to the collection units at different heights, and each sampling unit can be sampled separately by switching the valve ports, so as to avoid gas mixing and affecting the measurement accuracy. The dehumidifiers arranged at the front and rear ends of the sampling pump condense and remove water from the greenhouse gas, so as to avoid the adverse effects of water vapor on the multi-port switching valve, analyzer, etc.

[0016] The utility model measures the working condition of the front end of the sampling pipeline by a flow meter, and measures the working condition of the rear end of the sampling pipeline by a flow pressure control unit. When the pipeline is blocked, the abnormality can be judged by the value change of the flow meter.

[0017] The multi-port switching valve is used to switch the gas circuit of the entire sampling system, avoiding the situation in which the traditional measurement system reuses separate solenoid valves, and the pipelines are complex, easy to damage, and difficult to repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the utility model;

[0019] In the figure: 1-sampling tower, 11-sampling port, 2-multi-port switching valve, 21-inlet valve port, 22-outlet valve port, 23-calibration valve port, 3-measuring unit, 31-analyzer, 32-data acquisition and transmission module, 4-sampling pump, 5-pre-dehumidifier, 6-post-dehumidifier, 7-flow meter, 8-calibration unit, 9-filter, 10-flow pressure control unit. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] In the description of the present utility model, it should be noted that the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model.

[0022] See also Figure 1 The utility model discloses a greenhouse gas stratified measurement system, comprising three collection units arranged along the height direction of a sampling tower 1, a multi-port switching valve 2 connecting the three sampling units, and a measuring unit 3 connected to the other end of the multi-port switching valve 2; the sampling unit comprises a sampling pump 4, a front dehumidifier 5 and a rear dehumidifier 6 respectively arranged at both ends of the sampling pump 4, and a flowmeter 7 connected to the rear dehumidifier 6; wherein the other end of the flowmeter 7 is connected to the multi-port switching valve 2, and the sampling pump 4 is connected to the sampling port 11 of the sampling tower 1. The sampling pump 4 provides power for gas transportation, and the flowmeter is used to detect the flow of the sampled gas. The sampling flow of the sampling pump 4 is greater than the actual flow of the analyzer. When the front end pipeline is blocked, the flow will change significantly, so the flowmeter can be used to judge the working state of the sampling unit. By setting sampling units at different heights, the concentration of pollutants in the atmosphere in the vertical direction can be collected, and multiple collection units and the measuring unit 3 are connected through the multi-port switching valve 2, without the need to use a separate electromagnetic valve, which simplifies the communication and power supply lines and facilitates inspection and maintenance. Sampling units at different heights are sampled separately to avoid gas mixing.

[0023] Furthermore, it also includes a calibration unit 8 connected to the multi-port switching valve 2. The calibration unit 8 includes three standard gas tubes with different concentrations. The three standard gas tubes are filled with standard gases of different concentrations, two of which are low-concentration and high-concentration working standard gases, and the other is connected to the target gas. The concentration of the analyte in the target gas is close to the concentration in the atmosphere and the concentration is known, which is used to verify the measurement results; the high-concentration and low-concentration working standard gases are used to perform linear adjustment on the measurement unit to meet the accuracy requirements.

[0024] Furthermore, the multi-port switching valve 2 includes three air inlet valve ports 21 connected to the flow meter, an air outlet valve port 22 connected to the measuring unit 3, a calibration valve port 23 connected to three calibration gas pipes one by one, and also includes two spare valve ports.

[0025] Furthermore, the sampling unit also includes a filter 9 connected between the post-dehumidifier 6 and the multi-port switching valve 2 .

[0026] Furthermore, the sampling unit also includes a sampling tube connected between the pre-dehumidifier 5 and the sampling port 11. The sampling tube is made of PRFE material or stainless steel material, which is suitable for gas transportation.

[0027] Furthermore, the system also includes a flow pressure control unit 10 arranged between the multi-port switching valve 2 and the measuring unit 3. The flow pressure control unit 10 can be a flow meter to detect the gas flow entering the measuring unit 3 to determine the working status of the rear end of the pipeline.

[0028] Furthermore, the measuring unit 3 includes a plurality of analyzers 31 connected in parallel and a data acquisition and transmission module 32 connected to the analyzers 31. In the present embodiment, two analyzers are selected, one for measuring carbon dioxide in the air and the other for measuring methane content. The transmission module 32 transmits the data measured by the analyzer to the host computer for analysis, thereby realizing greenhouse gas measurement and monitoring.

[0029] When the utility model is in operation, Figure 1 As shown, the multi-port switching valve 2 is provided with 9 valve ports, valve port 1 is connected to the pipeline of the upper sampling unit, valve port 3 is connected to the pipeline of the lower sampling unit, valve port 2 can be connected to the pipeline of the middle sampling unit (not shown in the figure), valve ports 4 and 6 are respectively connected to the high-concentration working standard gas and the low-concentration working standard gas for instrument calibration, valve port 5 is connected to the target standard gas for verifying the gas to be measured, valve ports 7 and 8 are spare valve ports, and valve port 9 is the outlet valve port, which is connected to the flow pressure control unit 10. When it is necessary to measure high-rise greenhouse gases, valve ports 2 and 3 are closed and valve port 1 is opened. The air enters the front-end dehumidifier 5 through the sampling port 11 of the highest layer, passes through the sampling pump 4, is diverted by the flowmeter 7, enters the rear-end dehumidifier 6, and then enters the filter 9 to filter impurities, enters the valve port 1 of the multi-port switching valve 2 and enters the analyzer. When measuring the lower greenhouse gas, valve port 3 of the multi-port switching valve 2 is opened, valve ports 1 and 2 are closed, and the gas flows in the lower sampling unit 3 and enters the measuring unit 3 through the multi-port switching valve 2.

[0030] The analyzer needs to be calibrated regularly. During calibration, connect the No. 4 and No. 6 valve ports of the multi-port switching valve 2 to the No. 9 valve port, close the No. 5 valve port, connect the analyzer to the working standard gas, and adjust the linearization of the analyzer through the high-concentration working standard gas and the low-concentration working standard gas; verify the accuracy of the analyzer regularly every day, open the No. 5 valve port, close the No. 4 and No. 6 valve ports, connect the target standard gas to the analyzer, and compare the test results of the analyzer with the actual concentration of the target standard gas to verify the system measurement results to see if the difference is within the controllable range. If the difference is too large, recalibration is required.

[0031] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0032] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A greenhouse gas stratification measurement system, characterized in that: The invention comprises a plurality of collection units arranged along the height direction of a sampling tower (1), a multi-port switching valve (2) connecting the plurality of sampling units, and a measuring unit (3) connected to the other end of the multi-port switching valve (2); the sampling unit comprises a sampling pump (4), a front dehumidifier (5) and a rear dehumidifier (6) respectively arranged at the two ends of the sampling pump (4), and a flow meter (7) connected to the rear dehumidifier (6); wherein the other end of the flow meter (7) is connected to the multi-port switching valve (2), and the sampling pump (4) is connected to the sampling port (11) of the sampling tower (1).

2. The greenhouse gas stratification measurement system according to claim 1, characterized in that: It also includes a calibration unit (8) connected to the multi-port switching valve (2), and the calibration unit (8) includes three calibration gas pipes with different concentrations.

3. The greenhouse gas stratification measurement system according to claim 2, characterized in that: The multi-port switching valve (2) comprises an air inlet valve port (21) matching the number of flow meters, an air outlet valve port (22) connected to the measuring unit (3), and a calibration valve port (23) connected one by one to three calibration gas pipes.

4. The greenhouse gas stratification measurement system according to claim 1, characterized in that: The sampling unit also includes a filter (9) connected between the post-dehumidifier (6) and the multi-port switching valve (2).

5. The greenhouse gas stratification measurement system according to claim 1, characterized in that: The sampling unit also includes a sampling tube connected between the front dehumidifier (5) and the sampling port (11).

6. The greenhouse gas stratification measurement system according to claim 1, characterized in that: It also includes a flow pressure control unit (10) arranged between the multi-port switching valve (2) and the measuring unit (3).

7. The greenhouse gas stratification measurement system according to claim 1, characterized in that: The measuring unit (3) comprises a plurality of analyzers (31) connected in parallel and a data acquisition and transmission module (32) connected to the analyzers (31).

8. The greenhouse gas stratification measurement system according to claim 1, characterized in that: The number of sampling units is at least two.

9. The greenhouse gas stratification measurement system according to claim 3, characterized in that: The multi-port switching valve (2) further comprises at least two spare valve ports.

Images