Greenhouse gas monitoring system

When connecting the greenhouse gas monitoring system pipeline and branch pipe joints, in order to prevent the influence of condensation water flow and pipe wall airflow fluctuations, the connection end of the pipeline and branch pipe should be extended towards the center (or 1/2) of the main pipe, and then fixed.

ZYGHG201 typeGreenhouse gas monitoring systemBy adopting advanced cavity ring down technology (CRDS) and utilizing proprietary optical measurement structures and data processing algorithms, the measurement optical path can reach 30km, meeting the monitoring requirements for trace gases in the atmosphere. It can achieve continuous online monitoring of CO2, CH4, and H2O. The system complies with the World Meteorological Organization (WMO) and other international networks, helping to achieve "carbon peak and carbon neutrality" as soon as possible.

The principle of cavity ring down spectroscopy (CRDS) technology is to use two high reflectivity mirrors to form a stable optical resonant cavity. A gas sample is filled into the resonant cavity, and when the laser mode matches the cavity mode and the resonant signal reaches a certain intensity, the incident light is cut off. The light is reflected back and forth between the two high reflectivity mirrors, and each reflection outputs a portion of the light from the exit mirror, which is received by the detector. The collected light signal decays exponentially. By fitting the optical signal with the e-index, the decay time constant τ can be obtained, and the RingDown curve is shown in the figure:

Laser cavity decay curve

　　
The relationship between the absorption coefficient of the sample and the decay time constant is:

1.1 High precision greenhouse gas online analysis system

1.1.1 High precision greenhouse gas monitoring and analysis unit

1.1.2 Gas Sampling Module

(1) The sampling head is set at the gas inlet outside the main pipe to prevent rainwater and coarse particles from falling into the main pipe, while also avoiding birds, small animals, and large insects from entering the main pipe. The design of the sampling head should ensure that the sampling airflow is not affected by wind direction and enters the main pipe stably.

(2) The airflow inside the sampling manifold should maintain laminar flow, and the residence time of the sampling gas in the manifold should be less than 30 seconds.

(3) The materials used to make the sampling device should be selected to not react chemically with the monitored pollutants and not release interfering substances.

(4) The pipeline connecting the monitoring instrument to the branch pipe joint should be made of materials that do not undergo chemical reactions with the monitored pollutants and do not release interfering substances.

(5) To prevent dust from falling into the monitoring and analysis instrument, a filter membrane should be installed between the sampling inlet of the monitoring instrument and the junction of the branch gas path.

(6) When connecting the greenhouse gas monitoring system pipeline and branch pipe joints, in order to prevent the influence of condensation water flow and pipe wall airflow fluctuations, the connection end of the pipeline and branch pipe should be extended towards the center (or 1/2) of the main pipe, and then fixed.

(7) It should be installed on a suitable support (such as a sampling tower of a certain height).

(8) It should be placed in a dry protective groove (pipe) and properly fixed (the pipe can be elevated or introduced into the measurement room through an underground pipeline, and the height of the empty protective groove (pipe) should be set according to the actual terrain of the local area. The depth of the underground pipeline should be 0.5-0.8m, and a protective groove pipe for the sampling pipeline should be installed inside the underground pipeline).

(9) At least one spare sampling tube should be installed at the same height as the inlet of the sampling tube; The spare sampling tube should be sealed at both ports during non use.

(10) When there are multiple air sampling pipelines, the pipeline direction should be consistent, kept parallel, neat, and aesthetically pleasing, and fixed in appropriate positions.

(11) Try to use a complete sampling tube as much as possible. If an extended connection is needed, the joint should be tightly connected and easy to inspect and replace in the future.

(12) A particulate matter filtration device should be installed at the inlet of the sampling tube, and dust, water, insect, and corrosion prevention measures should be taken.

(13) The retention time of air from the sampling tube inlet to the analysis equipment should be less than 5 minutes.

1.1.3 Ultra low temperature fully automatic cold trap

1.1.4 Standard gas

CO2 and CH4 two element standard gases, fully imported 29.5L steel cylinders, equipped with inert coating two-stage pressure reducing valves, standard gases from the China Meteorological Administration Detection Center, traceable to the World Meteorological Organization WMO certification;

1.2 Data acquisition instrument

1.3 Analysis software

2、 Product features and advantages

Domestic independent research and development production, guaranteed quality, excellent after-sales service capabilities, and fast response speed;

Easy to operate, highly automated, highly stable, and requiring minimal maintenance, suitable for long-term online unmanned operation of monitoring stations;

Flexibly respond to the actual needs of different users for greenhouse gas observation and meet various observation requirements;

Easy installation, high integration degree, standard 19 inch cabinet integration.