CN206074150U - A kind of temperature monitoring system based on railway tunnel communications optical cable - Google Patents

Abstract

The utility model provides a temperature monitoring system based on a railway tunnel communication optical cable. The temperature monitoring system based on railway tunnel communication optical cable uses tunnel optical fiber as a temperature sensor, and includes: a laser source, a coupler, and a temperature measuring optical fiber arranged in sequence along the laser propagation direction, and a modulated laser for emitting from the laser source The first photoelectric channel for amplification processing, the second photoelectric channel for separating and amplifying the scattered echo fed back by the coupler, and the signal acquisition and processing unit for photoelectric signal acquisition and processing; the first photoelectric channel It is connected with the laser source, the second photoelectric channel is connected with the coupler, and the signal acquisition and processing unit is respectively connected with the first photoelectric channel and the second photoelectric channel.

Description

A Temperature Monitoring System Based on Communication Optical Cable in Railway Tunnel

technical field

The utility model relates to a temperature monitoring system based on a railway tunnel communication optical cable.

Background technique

In order to ensure the safety of trains running in the tunnel, it is necessary to monitor various technical indicators of the tunnel, such as temperature monitoring and fire monitoring. However, taking temperature detection as an example, the monitoring of tunnel temperature indicators still mainly depends on manual measurement, such as regularly sending people to the site to conduct long-distance measurement with infrared or laser thermometers. This manual measurement method mainly has the following problems:

1. The monitoring period is long, and fever phenomena in many places cannot be detected and dealt with in time;

2. The detection and analysis judgment is carried out manually, so the detection and analysis results are greatly affected by human factors;

3. Infrared or laser thermometers are often expensive, and affected by funds, it is difficult to popularize and promote them.

Therefore, it is necessary to propose a temperature monitoring system based on railway tunnel communication optical cables using tunnel optical fibers as temperature sensors.

Utility model content

The purpose of the utility model is to provide a temperature monitoring system based on railway tunnel communication optical cable using tunnel optical fiber as a temperature sensor.

The technical scheme of the utility model is as follows: a temperature monitoring system based on the railway tunnel communication optical cable uses the tunnel optical fiber as the temperature sensor, and includes: a laser source, a coupler, and a temperature measuring optical fiber arranged in sequence along the laser propagation direction; The first photoelectric channel for amplifying the modulated laser light emitted by the laser source, the second photoelectric channel for separating and amplifying the scattered echoes fed back by the coupler, and the signal acquisition and processing for photoelectric signal acquisition and processing unit; the first photoelectric channel is connected to the laser source, the second photoelectric channel is connected to the coupler, and the signal acquisition and processing unit is respectively connected to the first photoelectric channel and the second photoelectric channel channels are connected.

Preferably, the laser source includes a signal generator and a laser connected to each other, and the laser is connected to the coupler and the first photoelectric channel respectively.

Preferably, the laser is a high-power pulsed semiconductor laser.

Preferably, the first photoelectric channel includes a first photodiode and a first amplifier electrically connected to each other, and the first photodiode is connected to the laser source and receives modulated laser light emitted by the laser source; the first photodiode An amplifier is electrically connected to the signal acquisition and processing unit, and sends the first photoelectric signal to the signal acquisition and processing unit.

Preferably, the second photoelectric channel includes a filter, a second photodiode and a second amplifier connected in sequence, the filter is connected to the coupler, and receives the scattered echo fed back by the coupler, The second amplifier is electrically connected to the signal acquisition and processing unit, and sends a second photoelectric signal to the signal acquisition and processing unit.

Preferably, the signal acquisition and processing unit includes a data acquisition module and a computer electrically connected to each other, and the data acquisition module is electrically connected to the first photoelectric channel and the second photoelectric channel respectively.

Preferably, it also includes a single-chip microcomputer for confirming that the carrier signal frequency needs to be output, the single-chip microcomputer is electrically connected with the signal acquisition processing unit and the laser source, and confirms the said signal according to the electrical signal provided by the signal acquisition processing unit. The frequency of the carrier signal required to modulate the laser emitted by the laser source.

Preferably, the coupler is a Y-type directional coupler.

The beneficial effect of the utility model is that: the temperature monitoring system based on the railway tunnel communication optical cable adopts the initial modulation frequency whose size is equal to half of the frequency sampling interval, and accurately restores the actual anti-Stokes laser with a limited frequency sampling interval. The spatial distribution of Mann reflection enables the realization of high spatial resolution, long-distance power modulation type optical frequency domain Raman reflection fiber optic temperature sensor.

Description of drawings

Fig. 1 is the structural block diagram of the temperature monitoring system based on the railway tunnel communication optical cable that the utility model embodiment provides;

Fig. 2 is a schematic diagram of the coupler structure of the temperature monitoring system based on the railway tunnel communication optical cable shown in Fig. 1 .

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

Unless otherwise specifically and clearly described in the context, the elements and assemblies in the present invention may exist in a single form or in multiple forms, and the present invention is not limited thereto. It can be understood that the term "and/or" used herein refers to and covers any and all possible combinations of one or more of the associated listed items.

Please refer to FIG. 1 , which is a structural block diagram of a temperature monitoring system based on railway tunnel communication optical cables provided by an embodiment of the present invention. The temperature monitoring system 100 based on the railway tunnel communication optical cable utilizes the tunnel optical fiber as a temperature sensor, and includes a laser source 10, a coupler 20 and a temperature measuring optical fiber 30 arranged in sequence along the laser propagation direction, and is used to monitor the laser source 10 The first photoelectric channel 40 for amplifying the emitted modulated laser, the second photoelectric channel 50 for separating and amplifying the scattered echo fed back by the coupler 20, and the signal acquisition and processing unit for photoelectric signal acquisition and processing 60 and the single-chip microcomputer 70 for confirming that the frequency of the carrier signal needs to be output. In this embodiment, the temperature measuring optical fiber 30 is an optical fiber not used in the communication optical cable in the tunnel.

Wherein, the first photoelectric channel 40 is connected to the laser source 10, the second photoelectric channel 50 is connected to the coupler 20, and the signal acquisition and processing unit 60 is connected to the first photoelectric channel 40 respectively. It is connected with the second photoelectric channel 50 , and the single chip microcomputer 70 is electrically connected with the signal acquisition and processing unit 60 and the laser source 10 respectively.

The laser source 10 includes a signal generator 11 and a laser 12 connected to each other, and the laser 12 is connected to the coupler 20 and the first photoelectric channel 40 respectively. Specifically, the signal generator 11 is an AD9859 signal generator with a maximum output frequency up to 200MHz, and the laser 12 is a high-power pulsed semiconductor laser, and its main parameters are: center wavelength: 905nm; repetition rate (Prf): 5kHz ; Peak current (Ip): 4A; Peak power (Po): 10W; Coupling efficiency of laser and optical fiber: 65%.

In this embodiment, the signal generator 11 is electrically connected to the single-chip microcomputer 70, and outputs a periodic signal of a corresponding frequency according to an instruction of the single-chip microcomputer 70, such as a sine wave signal, a square wave signal, a triangular wave signal, etc.; The periodic signal passes through the laser 12 to obtain modulated laser light carrying the periodic signal. Moreover, the laser 12 generates two paths of the modulated laser light, one path of the modulated laser light enters the first photoelectric channel 40 , and the other path of the modulated laser light enters the temperature measuring optical fiber 30 through the coupler 20 .

In this embodiment, the coupler 20 is a Y-type directional coupler. Specifically, please refer to FIG. 2 , the selection principle of the coupler 20 is as follows: the loss of the 1-2 end and the 2-3 end of the coupler 20 is as small as possible, and the isolation between the 1-3 end and the 2-1 end The bigger the better. Moreover, the light entering the optical fiber is pulsed light, and the scattered light is quasi-continuous light, so the isolation at the 2-1 end needs to be made larger, so that the signal strength can be improved.

Specifically, the coupler 20 receives the scattered echo fed back by the temperature measuring fiber 30, such as the anti-Stokes Raman backscattered light echo generated by the temperature measuring fiber 30, and the coupler 20 also sends the scattered echo to the second photoelectric channel 50 , and performs signal separation and amplification processing on the scattered echo through the second photoelectric channel 50 .

The first photoelectric channel 40 includes a first photodiode 41 and a first amplifier 42 electrically connected to each other, the first photodiode 41 is connected to the laser source 10, and receives the modulated laser light emitted by the laser source 10; The first amplifier 42 is electrically connected to the signal acquisition and processing unit 60 , and sends a first photoelectric signal to the signal acquisition and processing unit 60 . Preferably, the first photodiode 41 is an avalanche photodiode.

Specifically, the first photodiode 41 is connected to the laser 12 of the laser source 10, receives the modulated laser emitted by the laser 12, and amplifies the modulated laser.

The second photoelectric channel 50 includes a filter 51, a second photodiode 52 and a second amplifier 53 connected in sequence, and the filter 51 is connected to the coupler 20 and receives feedback from the coupler 20. For scattered echoes, the second amplifier 53 is electrically connected to the signal acquisition and processing unit 60 , and sends a second photoelectric signal to the signal acquisition and processing unit 60 . Preferably, the second photodiode 52 is an avalanche photodiode.

Specifically, the filter 51 of the second photoelectric channel 50 receives the scattered echoes provided by the coupler 20, and separates the anti-Stokes Raman backscattering with temperature information in the scattered echoes. optical signal, and the separated anti-Stokes Raman backscattered optical signal is sent to the Raman channel of the second photodiode 52, and finally amplified by the second amplifier 53.

The signal acquisition and processing unit 60 includes a data acquisition module 61 and a computer 62 electrically connected to each other, and the data acquisition module 61 is electrically connected to the first photoelectric channel 40 and the second photoelectric channel 50 respectively. In this embodiment, the data acquisition module 61 is a CS series data acquisition card.

Specifically, the data acquisition module 61 receives the first photoelectric signal and the second photoelectric signal sent by the first photoelectric channel 40 and the second photoelectric channel 50 respectively, and from the measured laser power waveform Calculate the amplitude and phase of the anti-Stokes Raman reflection signal waveform respectively, and construct the frequency domain response function corresponding to the anti-Stokes Raman reflection signal, perform corresponding calculations, and then generate two signals, and send one to the The single-chip microcomputer 70 determines the frequency of the signal to be transmitted next time; the other channel is sent to the computer 62, and the computer 62 processes the collected data, and finally obtains the spatial distribution of the temperature and displays it in the form of a graph or a table.

The single-chip microcomputer 70 receives the signal sent by the data acquisition module 61, thereby confirming the frequency of the carrier signal to be output, and then sends an instruction to the signal generator 11 of the laser source 10, and after the signal generator 11 receives the instruction, Output a periodic signal corresponding to the frequency.

Compared with the prior art, the temperature monitoring system based on the railway tunnel communication optical cable provided by the utility model accurately restores the actual anti-Stokes with a finite frequency sampling interval by adopting an initial modulation frequency equal to half of the frequency sampling interval The spatial distribution of the Raman reflection enables the realization of a high spatial resolution, long-distance power-modulated optical frequency-domain Raman reflection fiber optic temperature sensor.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from all points of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, so it is intended to fall within the scope of the claims All changes within the meaning and range of equivalents of the required elements are included in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (8)

1. A temperature monitoring system based on railway tunnel communication optical cable is characterized in that, utilizes tunnel optical fiber as temperature sensor, and includes: laser source, coupler and temperature-measuring optical fiber arranged successively along laser propagation direction, and for all The first photoelectric channel for amplifying the modulated laser light emitted by the laser source, the second photoelectric channel for separating and amplifying the scattered echoes fed back by the coupler, and the signal acquisition and processing unit for photoelectric signal acquisition and processing ; The first photoelectric channel is connected to the laser source, the second photoelectric channel is connected to the coupler, and the signal acquisition and processing unit is connected to the first photoelectric channel and the second photoelectric channel respectively. connect. 2. The temperature monitoring system based on the railway tunnel communication optical cable according to claim 1, wherein the laser source includes a signal generator and a laser connected to each other, and the laser is connected to the coupler and the second laser respectively. An optical channel connection. 3. The temperature monitoring system based on the railway tunnel communication optical cable according to claim 2, wherein the laser is a high-power pulsed semiconductor laser. 4. the temperature monitoring system based on railway tunnel communication optical cable according to claim 1, is characterized in that, described first photoelectric channel comprises the first photodiode and the first amplifier that are electrically connected to each other, and described first photodiode and The laser source is connected to receive the modulated laser light emitted by the laser source; the first amplifier is electrically connected to the signal acquisition and processing unit, and sends a first photoelectric signal to the signal acquisition and processing unit. 5. The temperature monitoring system based on the railway tunnel communication optical cable according to claim 1, wherein the second photoelectric channel includes a filter, a second photodiode and a second amplifier connected in sequence, and the filter The second amplifier is connected to the coupler and receives the scattered echo fed back by the coupler, and the second amplifier is electrically connected to the signal acquisition and processing unit, and sends a second photoelectric signal to the signal acquisition and processing unit. 6. the temperature monitoring system based on railway tunnel communication optical cable according to claim 1, is characterized in that, described signal acquisition processing unit comprises the data acquisition module and computer that are electrically connected to each other, and described data acquisition module is connected with described first respectively A photoelectric channel is electrically connected with the second photoelectric channel. 7. the temperature monitoring system based on railway tunnel communication optical cable according to claim 1, is characterized in that, also comprises the single-chip microcomputer that is used to confirm needing to output carrier signal frequency, and described single-chip microcomputer is respectively connected with described signal acquisition processing unit and described The laser source is electrically connected, and the carrier signal frequency required for the modulated laser emitted by the laser source is confirmed according to the electrical signal provided by the signal acquisition and processing unit. 8. The temperature monitoring system based on the railway tunnel communication optical cable according to claim 1, wherein the coupler is a Y-type directional coupler.