Principles and Applications of Distributed Fiber Optical Temperature Sensing-INNO

Penginderaan Suhu Serat Optik Terdistribusi (DTS) adalah teknologi pemantauan suhu canggih yang memanfaatkan serat optik sebagai komponen sensitif suhu dan media transmisi sinyal untuk mencapai pemantauan distribusi suhu secara terus menerus dan real-time dalam jarak jauh dan rentang yang luas. Sistem DTS biasanya didasarkan pada prinsip reflektometri domain waktu optik (OTDR) dan efek hamburan Raman dari serat optik, dan memperoleh informasi distribusi suhu sepanjang serat dengan menganalisis perubahan intensitas hamburan Raman mundur cahaya pada serat.

1、Komponen utama sistem DTS

sumber cahaya
Laser: Laser berdenyut berdaya tinggi seperti Nd: Laser YAG atau penguat serat yang didoping Erbium (EDFA) laser umumnya digunakan. Sinyal cahaya pulsa yang dipancarkan oleh laser ditransmisikan ke area yang diukur melalui serat optik.
Serat optik
Merasakan serat: used for transmitting optical signals and serving as a temperature sensitive component. Common sensing fibers include single-mode fibers and multi-mode fibers. Single mode fiber is widely used due to its low loss and high resolution.
detektor
Fotodetektor: used to detect backscattered Raman light returning from optical fibers. The commonly used photodetectors include photomultiplier tubes (PMT) and avalanche photodiodes (APD).
unit pengolah sinyal
Data acquisition card: used to collect electrical signals output by photodetectors and convert them into digital signals.
Signal processor: processes the collected digital signals and extracts temperature information. Common signal processing algorithms include Fourier transform, wavelet transform, dll..
software system
Data analysis software: used to display and analyze temperature distribution data, generate temperature curves and temperature distribution graphs. Software systems typically have data storage, alarm functions, dan kemampuan pemantauan jarak jauh.
The working principle of DTS system
Principle of Optical Time Domain Reflectometry (OTDR)
The pulse light signal emitted by the laser propagates along the optical fiber, and when it encounters uneven points or end faces in the fiber, it will produce backscattered light. By measuring the return time and intensity of backscattered light, the propagation distance and position of the optical signal in the fiber can be determined.
Raman berhamburan
When optical signals propagate in optical fibers, various types of scattering occur, including Rayleigh scattering, Hamburan brillouin, dan Raman berhamburan. Intensitas cahaya hamburan Raman bergantung pada suhu. Raman scattering is divided into Stokes scattering and Anti Stokes scattering. The intensity of anti Stokes scattering light increases with temperature, while the intensity of Stokes scattering light does not change significantly with temperature. By measuring the intensity ratio of anti Stokes scattering light to Stokes scattering light, the temperature at each point along the fiber can be calculated.

2、Application scenarios of DTS system

Sistem tenaga
Pemantauan suhu kabel: In high-voltage cables and cable trenches, DTS system can monitor the temperature distribution of cables in real time, detect overheating problems in a timely manner, and prevent cable damage and fire accidents.
Substation temperature monitoring: In the substation, the DTS system can monitor the temperature of equipment such as transformers and switchgear to ensure the safe operation of the equipment.
Oil and gas industry
Oil pipeline monitoring: In long-distance oil pipelines, the DTS system can monitor the temperature distribution of the pipeline in real time, detect leakage points and temperature anomalies in a timely manner, and prevent environmental pollution and economic losses.
Oil well temperature monitoring: Di sumur minyak, DTS systems can monitor the temperature distribution underground, providing data support for oil extraction.
Architecture and Infrastructure
Bridge temperature monitoring: In large bridges, DTS systems can monitor the temperature distribution of the bridge body, evaluate the health status of the bridge, and promptly detect potential safety hazards.
Tunnel temperature monitoring: In tunnels, DTS systems can monitor the temperature distribution inside the tunnel to ensure its safe operation.
perlindungan lingkungan
Pemantauan suhu tanah: Dalam penelitian pertanian dan ekologi, DTS systems can monitor soil temperature distribution, provide guidance for agricultural production, and study soil microbial activity and nutrient transformation.
Pemantauan suhu air: In rivers, danau, dan lautan, DTS systems can monitor the temperature distribution of water bodies and study the impacts of water ecosystems and climate change.
keselamatan kebakaran
Warehouse temperature monitoring: In large warehouses, DTS systems can monitor the temperature distribution inside the warehouse, detect fire hazards in a timely manner, and prevent fire accidents.
Tunnel fire monitoring: In tunnels, DTS systems can monitor the temperature distribution inside the tunnel in real time, detect fires in a timely manner, and activate the fire protection system.

3、Advantages of DTS system

Long distance monitoring: The DTS system can achieve temperature monitoring for up to tens of kilometers, suitable for large-scale, long-distance temperature monitoring scenarios.
High resolution: DTS systems can provide temperature distribution data with high spatial resolution, typically up to several meters or even shorter.
Pemantauan waktu nyata: The DTS system can achieve real-time and continuous temperature monitoring, dan mendeteksi anomali suhu secara tepat waktu.
Interferensi anti elektromagnetik: Optical fibers have good anti electromagnetic interference capabilities and are suitable for temperature monitoring in strong electromagnetic environments.
Instalasi mudah: The installation and maintenance of DTS system are relatively simple and cost-effective.

4、Limitations of DTS system

Biaya: Although the unit cost of DTS system decreases with the increase of monitoring distance, the initial investment cost is still relatively high.
Accuracy limitation: The temperature measurement accuracy of DTS system is affected by various factors, such as fiber quality, environmental temperature changes, external interference, dll..
Complex data processing: DTS systems require complex signal processing algorithms and high-performance computer systems to process large amounts of data.
ringkasan
Itu Penginderaan Suhu Serat Optik Terdistribusi (DTS) system is an advanced temperature monitoring technology that utilizes the Raman scattering effect and optical time domain reflection principle of optical fibers to achieve continuous and real-time monitoring of temperature distribution over long distances and large ranges. DTS system has a wide range of applications in the fields of power system, oil and gas industry, construction and infrastructure, perlindungan lingkungan, keselamatan kebakaran, dll.. It has advantages such as long-distance monitoring, resolusi tinggi, pemantauan waktu nyata, interferensi anti elektromagnetik, dan instalasi mudah. Namun, DTS systems also have limitations such as high cost, accuracy limitations, and complex data processing.