In-situ detection system for concentration of methane in deep sea

Abstract

The invention provides an in-situ detection system for the concentration of methane in deep sea. The in-situ detection system is characterized in that by utilizing the characteristic that methane gas absorbs infrared light, methane components in a seawater water sample are separated by a gas-liquid separation technology, and then the content of the methane components is detected by using an infrared sensor. The detection system is composed of a flange disc, a decompression valve, a decompression cabin, a water inlet pump, a high-pressure-resisting water outlet pump, a gas pump, a solenoid valve, a circuit board, a gas-liquid separation optical detection chamber, a fixed bottom plate, a fixed bracket and a shell; and the appearance of the in-situ detection system is a small-size sealing device with a water inlet/outlet and an electric watertight connector. The in-situ detection system has a small response degree of non-methane gas and a high system signal-to-noise ratio; under a condition that ocean current of the deep sea fluctuates violently, the in-situ detection system has a strong anti-interference capability, a simple structure, a small size and low cost, and the integration of a small-size ocean monitoring system with relatively strong environment adaptability is convenient to realize; and the in-situ detection system can be distributed in a bad environment of the deep sea, and a concentration index of the methane in seawater can be subjected to in-situ detection under a long-time unmanned duty condition.

Description

technical field [0001] The invention belongs to the technical field of water body monitoring, and relates to a detection system for methane content in water, in particular to an in-situ detection system for deep-sea methane concentration. Background technique [0002] At present, there are mainly the following two systems for the detection of methane content in deep seawater at home and abroad: [0003] One is a semiconductor gas-sensing in-situ methane measurement system, which uses the oxide semiconductor gas-sensing material SnO 2 Adsorption or desorption of gas molecules will cause changes in conductivity to measure methane gas, which is characterized by a large measurement range, up to 50nmol / L-10μmol / L, and a deep working water depth, up to 3500m, but due to the semiconductor material Gas sensitive material SnO 2 Due to the inherent detection characteristics, other gases entering the detection chamber may also be oxidized, thereby interfering with the oxygen adsorpti...

AI Technical Summary

Problems solved by technology

[0006] (1) The semiconductor gas-sensitive in-situ methane measurement system has poor stability in deep-sea applications;

[0007] (2) The semiconductor gas-sensitive in-situ methane measurement system is not sensitive in the dynamic environment of water flow;

[0008] (3) The in-situ methane measurement system for laser Raman spectroscopy is complex in structure and expensive, and it is difficult to promote it in practical applications

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