DTS Fiber dts fiber optic-INNO

Обговорення розподіленого волокна DTS Fiber

1、 Принцип розподіленої волоконно-оптичної системи вимірювання температури DTS

Основні принципи розподілених волоконно-оптичних систем вимірювання температури (DTS) засновані на оптичній рефлектометрії у часовій області (OTDR) принцип оптичних волокон і ефект комбінаційного розсіювання оптичних волокон.

При взаємодії лазерних імпульсів з молекулами волокна, виникають різні явища розсіювання, such as Rayleigh scattering, Бріллюенівське розсіювання, і комбінаційне розсіяння. В теорії, всі три типи розсіювання могли бути використані як опорні сигнали для вимірювання температури. Проте, багаторічні дослідження показали, що інтенсивність релеївського розсіювання вкрай нестабільна до втрат чутливості оптичних волокон. Якщо релеївське розсіювання світла використовується як опорний сигнал для систем вимірювання температури протягом тривалого часу, це спричинить невизначеність у характеристиках втрат оптичних волокон, призводить до зниження стабільності системи та навіть неможливості її роботи. тому, система вибирає комбінаційне розсіювання, чутливе до змін температури, як опорний сигнал.

Комбінаційне розсіювання генерується тепловими коливаннями молекул волокна, який створює стоксове світло, довше за довжину хвилі джерела світла, і антистоксове світло, коротше за довжину хвилі джерела світла. Модуляція оптичного волокна зовнішньою температурою спричинить зміни антистоксової інтенсивності у волокні. Співвідношення антистоксів до стоксів може забезпечити абсолютну індикацію температури. У поєднанні з високоякісними джерелами імпульсного світла та високошвидкісною технологією збору та обробки сигналу, точні значення температури можна отримати в усіх точках уздовж волокна.

The DTS system includes a pulsed laser that sends approximately 1m pulses (еквівалентно 10 нс часу) to the fiber optic cable. When the pulse propagates along the optical fiber and interacts with the glass, a small amount of the original laser pulse is reflected back to the DTS sensing system due to small defects in the glass. Аналізуючи відбите світло, DTS can calculate the temperature of the event (based on the power of the reflected light) and the location of the event (based on measuring the time it takes for the backscattered light to return).

This technology has some characteristics, наприклад моніторинг у реальному часі. The system can monitor the temperature of the tested area in real-time for 7 × 24 години, detect and locate temperature anomalies in a timely manner, and provide early warning; Its continuous distributed measurement capability can achieve simultaneous monitoring of multiple points and events without affecting each other, and the part before the fiber break can still work normally, with strong resistance to destruction; Крім того, it has ultra-high precision and high sensitivity. The system parameters can be configured according to the environment, and standard communication optical cables can be directly used. The monitoring area is divided according to on-site requirements; The response is very rapid, with a scanning cycle as low as 1 другий. Загалом, DTS utilizes the Raman scattering effect of light in optical fibers and the propagation characteristics of light to achieve effective measurement of temperature distribution along the fiber.

2、 DTS Fiber Distributed Fiber Types

Classify according to the different optical fibers used
Multimode fiber optic sensor: Fiber optic cables that can transmit multiple transmission modes are called multimode fibers. In multimode fiber optic sensors, the transmission type fiber optic sensor uses multimode optical fibers to transmit optical signals and measures them based on different light reception intensities. This type of sensor is commonly used for industrial detection, such as detecting liquid level, тиск, deformation, температура, швидкість потоку, поточний, magnetic field, тощо. It has the advantages of stable and reliable performance, проста структура, and low cost, but its sensitivity is relatively low. The transmission bandwidth of multimode fiber can reach 30 megahertz to several hundred megahertz, making it suitable for sensing and measurement over shorter distances (up to 40km). Наприклад, in some temperature and physical quantity sensing and monitoring scenarios where distance requirements are not particularly long and cost needs to be controlled, multimode fiber type distributed fiber sensors will be used.
Single mode fiber optic sensor: A type of optical fiber with a very thin core and cladding (with a small refractive index difference between the core and cladding) that can only transmit one transmission mode, called a single-mode fiber. This single-mode fiber optic sensor can be constructed using single-mode optical fibers to form interferometers. External factors can cause changes in the optical path in the optical fiber, resulting in variations in interference fringes, which can be used for measuring various physical quantities. Single mode fiber optic transmission has a bandwidth of up to 10 gigahertz, підходить для міжміських перевезень (40-100км) вимірювань. In scenarios that require long-distance розподілене оптоволокно зондування, such as temperature and strain monitoring of oil and gas pipelines, single-mode fiber optic sensors can play a role by stably transmitting optical signals over long distances to achieve sensing functions.
Classified by sensing function
Raman Thermometry (DTS): This type is based on the Raman scattering effect to measure temperature. It is a standalone temperature measurement system that measures the temperature distribution along the fiber by utilizing the temperature dependent relationship between the Stokes and anti Stokes intensity ratio generated by Raman scattering in the fiber. Its price is relatively cheaper than the Brillouin type, usually in the tens of thousands of yuan. Raman type DTS is widely used in many scenarios that require temperature monitoring, such as temperature monitoring and warning systems in buildings, промислове обладнання, power cable trenches, тощо. By distributing sensors in these places, real-time temperature changes can be monitored to avoid safety hazards caused by abnormal temperatures. Наприклад, in power cable trenches, temperature increases caused by overload or local faults can be detected in a timely manner to prevent accidents such as cable fires.
Brillouin type (such as BOTDR): This type of distributed fiber optic sensor can simultaneously measure temperature and stress, based on the Brillouin scattering effect. Two optical fibers are required on site, one for temperature measurement and one for stress measurement, but the cost is very high, with prices reaching millions. Although Brillouin type distributed fiber optic sensors are expensive, they have important applications in some special engineering and scientific research scenarios that require simultaneous measurement of temperature and stress. Наприклад, in the structural health monitoring of large bridges, Brillouin type distributed fiber optic sensors can be used to obtain the temperature distribution and stress distribution of the bridge under different working conditions, which is of great significance for the safety assessment and life prediction of the bridge. Проте, due to their high cost, they are rarely used in ordinary civilian scenarios.

3、 DTS Fiber Distributed Fiber Application

Fire alarm field
In fire alarm systems in large spaces such as subways, автодорожні тунелі, складські приміщення, тощо, distributed fiber optic temperature measurement systems play a good role in temperature monitoring and fire monitoring. In highway tunnels, the detection fiber optic cable is installed at the top middle position of the tunnel. If it is a closed tunnel, the fiber optic cable can also be placed on the side or top middle position of the tunnel (and 1m away from the wall) for easy monitoring. The detection optical cable needs to be fixed at regular intervals. The fiber optic host is placed in a monitoring room with good environmental conditions, and its display can show the main interface of the monitoring system. The working mode can be selected according to the usage requirements, and it can be used for real-time temperature monitoring, real-time monitoring of spatial temperature field distribution, alarm and other operations. And the fiber optic host can be connected to the fire alarm controller, setting partition parameters according to the actual spatial distribution, such as alarm temperature, partition range, тощо. The number of partitions can reach hundreds, and each partition can independently sound an alarm.
For some special places where flammable materials or high fire risks are stored, such as crude oil storage tanks, when installing fire automatic detection devices on oil tanks, distributed fiber optic temperature sensors can be installed on the secondary sealing ring of the oil tank float. Distributed fiber optic temperature sensors can be regarded as continuous distributed temperature fire detectors here, which can measure the temperature at any point along the fiber optic cable without blind spots. They can quickly respond to temperature changes, timely warn of fire hazards, ensure the safety of oil tanks, and prevent serious consequences such as oil and gas explosions caused by abnormal temperature increases.
Monitoring of power facilities
For temperature monitoring of power devices such as high-voltage transmission and distribution cables, силові кабелі, кабельні траншеї, and power equipment, the temperature distribution and temperature change trend of the high-voltage cables covered by the detection optical cables can be monitored in real time by laying detection optical cables on the high-voltage cables to be tested. High voltage cables can also be divided into several areas and monitored separately according to requirements, with segmented functions such as warning temperature, alarm temperature, heating rate, and temperature difference alarm. The distributed fiber optic monitoring and alarm system provides an effective way for temperature monitoring, тривога, аналіз, and management of high-voltage cables and other power devices, which helps to timely detect faults such as cable overheating and ensure the stability and safety of power supply. Due to its use of optical fiber as a medium, it is not affected by electromagnetic interference like some traditional electrical sensors, and linear distribution detection can fully cover the cable without any monitoring blank areas.
It is also applied in temperature monitoring of power equipment such as switchgear and transformers. It can achieve distributed temperature measurement of these devices, timely grasp the temperature situation during device operation, prevent equipment damage caused by high temperature, and improve the reliability and safety of power equipment operation. In substations or distribution rooms, distributed fiber optic temperature sensors can be arranged along key parts of switchgear and transformers, such as around the windings of transformers, which can sensitively capture small temperature changes in equipment and help power workers take maintenance measures in advance.
Monitoring of oil and gas storage tanks
The temperature rise of oil and gas storage tanks can lead to an increase in pressure inside the tanks, which may cause serious consequences. By using distributed fiber optic temperature sensors and laying detection cables on the outer surface and top of oil and gas storage tanks, the temperature distribution and trend of the entire tank can be monitored. When the alarm condition is reached, the system outputs an alarm signal. This monitoring method has many advantages, such as real-time monitoring of the entire oil and gas tank to provide comprehensive temperature analysis; Flexible setting of constant temperature alarm, differential temperature alarm, and temperature rate alarm; The detection cable is non electrified, corrosion-resistant, and can work safely in hazardous environments; Легко встановити, one optical cable can simultaneously measure dozens of oil and gas tanks; Through proper installation, it is also possible to measure whether there are leaks in oil and gas tanks. The DTS system has the characteristics of strong environmental adaptability and high long-term stability, making it suitable for long-term temperature monitoring of oil and gas storage tanks.
Моніторинг трубопроводів
In terms of pipeline monitoring, whether it is liquid or gas transportation pipelines, especially in the important pipeline parts of underground transportation in the energy industry, поширюється волоконно-оптичний датчик температури technology can be used for pipeline monitoring, виявлення витоку, and data measurement during pipeline transportation, включаючи виявлення трубопроводів і витоків, розташування витоків, та забезпечення допоміжним обладнанням для існуючих трубопроводів. Наприклад, в нафто- і газотранспортних трубопроводах, шляхом прокладання оптичних волокон уздовж трубопроводу, є можливість стежити за змінами температури навколишнього середовища або самого трубопроводу в реальному часі. Якщо є витік або інші ситуації, температура навколо місця витоку може змінитися. Система DTS може виявити цю температурну аномалію та точно визначити місце витоку, що має велике значення для запобігання економічних втрат (наприклад, матеріальні втрати, спричинені витоками нафти та газу) і забруднення навколишнього середовища.
Застосування, пов'язані з водозбереженням будівельних конструкцій
При перевірці та вимірюванні стану безпеки водоохоронних споруд, таких як дамби, distributed fiber optic temperature sensors can not only measure the temperature distribution field of dams and other buildings, but also play a role in temperature measurement during concrete pouring. They can also detect dam leakage and locate leakage points. Distributed fiber optic deformation measurement technology also allows for static measurement and dynamic deformation measurement of hydraulic building structures. In reservoirs, моніторинг температури, concrete dam monitoring, leakage detection and positioning, water leakage path positioning, measurement of subsidence process, deformation measurement, rock layer research and other work can be carried out; In terms of dams and embankments, моніторинг температури, dam and embankment monitoring, leakage detection and positioning, positioning of groundwater leakage paths, leakage detection of sealing bodies and joints, and other monitoring work can be carried out, забезпечення комплексних методів моніторингу даних для гарантії безпеки водозберігаючих будівель.

4、 InnoTech – найкраща компанія в галузі DTS

Fuzhou Yingnuo Electronic Technology Co., ТОВ. – це високотехнологічне підприємство, яке займається науковими дослідженнями та розробками, виробництва, sales, and service. Компанія має ряд продуктів і досягнень у DTS.

Технічні дослідження та характеристики продукції
Технологія розподіленої волоконно-оптичної системи вимірювання температури Yingnuo Technology базується на основних принципах DTS, наприклад, використання оптоволоконного ефекту спонтанного комбінаційного розсіювання для досягнення вимірювання температури та оптичного відбиття у часовій області для функції просторового позиціонування. Його продукти, наприклад хост вимірювання IF-DTS, може використовувати високошвидкісні вузькоімпульсні напівпровідникові лазерні імпульси, з’єднані в чутливе волокно, і далі фільтрувати, detect, and collect high-speed data through the weak backscattering signal of the fiber to obtain temperature sensitive anti Stokes signals and temperature insensitive Stokes signals, thereby obtaining accurate temperature information distributed along the fiber. And combined with advanced fire intelligent alarm judgment algorithms, achieve real-time online monitoring of the entire sensing fiber optic process.

The product has some outstanding features, such as a measurement range of -30.0 ℃~240.0 ℃, distributed real-time measurement function, which can cover the detection area and accurately locate the location of the fire; Long measurement distance and rich measurement information; High measurement accuracy and fast response speed; High reliability and low false alarm rate; The alarm method is flexible and can achieve multi-level differential temperature alarm, ensuring reliable alarm in the early stage of a fire. Крім того, the detection optical cable serves as both a signal transmission carrier and a temperature sensing element, with advantages such as easy installation, тривалий термін служби, and low maintenance costs in the later stages.

Yingnuo Technology’s products have a wide range of applications, наприклад тунелі, метро, електроенергія, нафтохімії, греблі, oil wells, та інші поля. Compared with other traditional methods in tunnel fire monitoring, the advantages of high precision and accurate positioning through distributed fiber optic temperature measurement can more timely detect fire hazards. Real time monitoring of various key equipment temperatures can be achieved in power equipment monitoring, reducing equipment operation risks. Крім того, the product has a certain cost advantage and can provide products and services at relatively reasonable prices in the market (such as the IF-DTS distributed fiber optic temperature measurement system with different price options), which is very attractive for large-scale projects that require the deployment of a large number of sensors.