Multi-optical fiber channel laser infrared gas sensor

Abstract

The invention discloses a multi-optical fiber channel laser infrared gas sensor comprising a circuit and man-machine exchange module, at least one semiconductor thermoelectric refrigerator, a laser, at least one infrared detector and an optical fiber probe, wherein the circuit and man-machine exchange module is used for power supply management, system control, and the phase-locking amplification, the collection, the storage, the analysis and the reading of signals as well as man-machine interaction; the semiconductor thermoelectric refrigerator is connected with the circuit and man-machine exchange module and is used for realizing temperature control; the laser is fixed on the semiconductor thermoelectric refrigerator, is connected with the circuit and man-machine exchange module, and is used for transmitting infrared laser; the infrared detector is fixed on the semiconductor thermoelectric refrigerator, is connected with the circuit and man-machine exchange module, and is used for receiving infrared laser; and the optical fiber probe is connected with the laser and the infrared detector through an optical fiber and is used for detecting a plurality of gas points to be detected. The invention can detect gas in the distance or corners with higher safety and simultaneously detect a plurality of gas measuring points, improves the integration, and lowers the cost.

Description

technical field [0001] The invention relates to an infrared gas sensor, in particular to a laser infrared gas sensor with multiple optical fiber channels. Background technique [0002] In the petrochemical industry and mineral development, there are often flammable gases such as carbon monoxide, alkanes, alkenes, and alkynes, and organic vapors such as benzene, aldehydes, and ketones. They are flammable and explosive, and pose a huge threat to production safety and environmental protection. It must be closely monitored in real time. There are mainly two types of sensors for detecting flammable gases: catalytic combustion and infrared absorption. The catalytic combustion sensor is relatively easy to design and manufacture, and the price is relatively low. But it has the following serious defects: the reaction requires oxygen to participate, that is, the oxygen content in the detected environment cannot be too low, and its detection value will be low when the oxygen content ...

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Problems solved by technology

But it has the following serious defects: the reaction requires oxygen to participate, that is, the oxygen content in the detected environment cannot be too low, and its detection value will be low when the oxygen content is lower than 16%; there are silicon, chlorine, When sulfur and other compounds are used, the sensor will be poisoned, the sensitivity will be seriously reduced or even completely invalid; it can only detect low combustible gas concentration, the gas concentration is too high or long-term exposure to low concentration gas will cause the sensitivity of the sensor to be greatly reduced or damaged; Slow, noticeable lag; poor stability, requires recalibration every few months

However, general laser infrared gas sensors are not suitable for combustible gas monitoring. The reason is that the infrared light source used is a quantum cascade laser, which has a large operating current and strong heat generation. It needs to use a semiconductor thermoelectric cooler to cool and stabilize the temperature. If the refrigerator fails or the sensor does not discharge heat in time, flammable and explosive gases may be ignited, resulting in catastrophic consequences

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