Connected petroleum storage tank leakage monitoring device based on fiber oxygen sensing

Abstract

The invention discloses a connected petroleum storage tank leakage monitoring device based on fiber oxygen sensing; the monitoring device comprises a laser drive, a sensor and a photoelectric detector; the left side of a laser is connected with the laser drive and a signal generation module; the right side of the laser is connected with an optical switch via a circulator; a preamplifier is connected with the control center via a data collection card; the control center is connected with the bottom of the optical switch. The monitoring device is reasonable and scientific in structure, easy andsafe to use, low in cost, simple in structure, can be widely promoted and mounted, and can be applied to long time unmanned monitoring in various combustible gas stations; optical signal transmissioncan be realized so as to improve the response speed; a metallurgy powder sleeve can prevent water molecules from entering the fiber oxygen sensor; oxygen molecules with the inherent vibration frequency at 760 nanometer of the oxygen can absorb the spectrum; the whole sensing structure is passive, electrically neutral, and thus preventing electromagnetic interferences of a traditional sensor from causing hidden troubles.

Description

technical field [0001] The invention relates to the technical field of VOC leakage safety monitoring in the area of ​​connected petroleum storage tanks, in particular to a leakage monitoring device for connected petroleum storage tanks based on optical fiber oxygen sensing. Background technique [0002] For the connected storage tank, the gas phase is connected. Normally, the VOC in the storage tank will not leak and cause environmental pollution. However, due to factors such as valves and corrosion in the connected pipeline, VOC will be in direct contact with air, which can easily cause an explosion. Passed the test The concentration of oxygen can reflect the sealing effect of Unicom storage tanks and provide guarantee for the safe operation of storage tanks. The sensors used for natural gas leakage detection mainly include semiconductor gas sensors, electrochemical gas sensors, and solid electrolyte gas sensors. , contact combustion gas sensors, etc. These sensors generall...

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Problems solved by technology

[0002] For the connected storage tank, the gas phase is connected. Normally, the VOC in the storage tank will not leak and cause environmental pollution. However, due to factors such as valves and corrosion in the connected pipeline, VOC will be in direct contact with air, which can easily cause an explosion. Passed the test The concentration of oxygen can reflect the sealing effect of Unicom storage tanks and provide guarantee for the safe operation of storage tanks. The sensors used for natural gas leakage detection mainly include semiconductor gas sensors, electrochemical gas sensors, and solid electrolyte gas sensors. , contact combustion gas sensors, etc. These sensors generally have the disadvantages of slow response, easy to be interfered by other gas components, frequent maintenance, and low measurement accuracy. It is difficult to realize remote, real-time, online monitoring. The biggest disadvantage of this type of sensor is It is charged by itself, and there are safety hazards when it is used in special environments such as flammable and explosive. In recent years, research in this field has developed rapidly at home and abroad, especially the optical detection method based on laser absorption spectroscopy technology for natural gas leakage. Monitoring, including non-dispersive infrared absorption (NDIR), Fourier transform infrared (FTIR) spectrometer and tunable semiconductor laser spectroscopy (TDLAS), has the advantages of fast response and high detection efficiency, but NDIR and FTIR are based on the use of near-infrared Bands of molecular absorption spectra brought for detection, CO in air 2 and H 2 The influence of O and other gases makes the background of the measurement signal large, the accuracy is low, and it is not suitable for remote measurement. However, Tunable Semiconductor Laser Spectroscopy (TDLAS) has the advantages of high sensitivity, high resolution, and fast response to realize remote, on-line, and in-situ monitoring. It has become the main technology of new natural gas leakage monitoring instruments, and there are handheld methane gas remote detector products using this technology on the market abroad. The sensitivity can reach ppm level, the response time is 0.1s, but the measurement distance is less than 10m. There are also relevant vehicle-mounted and airborne leakage monitoring equipment for on-site experiments. Some extractive combustible gas detection devices have been developed by some companies, but this extractive equipment must extract and sample the on-site gas, and the detection time increases, which is not suitable for use in tunnels. It is used in dangerous places such as natural gas stations, and there is currently no effective monitoring method for the monitoring of oxygen in this application environment.

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