Distributed optical fiber temperature sensing measurement device and method

Abstract

The invention relates to a distributed optical fiber temperature sensing measurement device which comprises a measuring host machine and a sensing optical cable, wherein the measuring host machine comprises a laser, a light split module, a detection module and an analysis unit; the device is characterized in that the sensing optical cable is provided with a temperature sensor; the light split module is used for respectively filtering out scattered lights transmitted along the sensing optical cable and reflected lights / transmitted lights of the temperature sensor and transmitting the scattered lights and the reflected lights / transmitted lights to the analysis unit by the detection module; and the analysis unit is used for obtaining distributed temperature measuring data according to the information of the scattered lights and obtaining dot-type temperature measuring data according to the information of the scattered lights and the reflected lights. The invention also provides a distributed optical temperature sensing measurement method. The device and the method combine the distributed measurement function and the dot-type measurement function, can also carry out on-line temperature correction and have the advantages of simple structure, low cost and the like.

Description

technical field [0001] The invention relates to an optical fiber temperature sensing and measuring device and method, in particular to a distributed optical fiber temperature sensing and measuring device and method with a point temperature measuring function. Background technique [0002] Distributed optical fiber temperature sensing system is a new real-time and distributed measurement system based on OTDR technology and Raman scattering technology. Distributed optical fiber temperature sensing devices have been widely used in highway traffic tunnels, high-voltage cable trenches, subways and other fields. [0003] At present, a widely used distributed optical fiber temperature sensing device includes a light source module, a light splitting module, a detection module, a reference unit and a sensing optical cable. The reference unit includes a section of reference optical fiber. The temperature of the reference optical fiber can be constant or measured in real time; the ref...

AI Technical Summary

Problems solved by technology

However, since the sensing optical cables are all installed outdoors, such as distributed optical fiber temperature sensing devices used in traffic tunnels, the sensing optical cables are laid at a distance of about 100mm from the tunnel vault, and the height from the ground is close to 7m, so it is not easy to heat it calibration

Moreover, the conventional water bath calibration method cannot perform real-time online calibration, which affects the reliability of the distributed optical fiber temperature sensing device

[0006] In addition, for some applications, for example, some special or critical parts require higher temperature measurement accuracy (short heating area), or need to improve the response time of temperature measurement, only the distributed temperature measurement function cannot meet the application requirements:

[0007] For example, in the field of power applications, it is necessary to monitor high-voltage cables and switch cabinets at the same time; when monitoring overheating of linear high-voltage cables, the use of distributed temperature measurement can effectively avoid measurement blind spots, thereby realizing complete monitoring of high-voltage cables; The temperature monitoring of high-voltage switchgear is mainly to monitor the temperature at the busbar and contacts inside the switchgear. The area to be tested is relatively small, and it is inconvenient to lay sensing optical cables in the area to be tested, and the traditional distributed optical fiber temperature sensor The temperature measurement accuracy of the system is limited by the spatial resolution, and the temperature monitoring of small monitoring points in the area to be measured is inaccurate;

[0008] As another example, for a long-distance highway traffic tunnel, the use of a distributed optical fiber temperature sensing system can achieve comprehensive monitoring of the fire in the measurement area; Drift will occur, and the temperature response time of the sensing cable will lag behind, causing the system to obtain the position of the ignition point after the drift of the hot spot; making the system's positioning of the ignition point inaccurate, unable to reflect the temperature change in the monitoring area in time, and delaying the detection of the fire. Response time affects the accuracy and timeliness of temperature measurement

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