fiber optics solutions for extreme environments-INNO

Cảm biến nhiệt độ sợi quang huỳnh quang có nhiều ưu điểm phù hợp với môi trường khắc nghiệt:

Độ nhạy cao: Nó có thể đạt được độ nhạy cực cao, cho phép cảm nhận chính xác những thay đổi nhiệt độ nhỏ ngay cả trong môi trường khắc nghiệt. Ví dụ, trong một số tình huống nghiên cứu khoa học hoặc quy trình kiểm soát công nghiệp chính xác cực kỳ nhạy cảm với sự thay đổi nhiệt độ, độ nhạy cao đảm bảo độ chính xác của phép đo.
Không bị ảnh hưởng bởi nhiễu điện từ: Dựa trên sợi quang huỳnh quang để đo nhiệt độ, nó không bị ảnh hưởng bởi nhiễu điện từ từ môi trường xung quanh. Trong giám sát thiết bị công nghiệp dưới trường điện từ mạnh, đo nhiệt độ thiết bị trạm biến áp lớn, hoặc các địa điểm nghiên cứu khoa học đặc biệt có môi trường bức xạ điện từ phức tạp, ưu điểm này đảm bảo độ tin cậy của dữ liệu đo nhiệt độ, while traditional metal probe sensors may cause measurement errors due to electromagnetic interference.
Remote measurement capability: The transmission distance of optical fiber can reach tens of meters without affecting measurement accuracy. In some dangerous extreme environments, such as near high-temperature furnaces and nuclear radiation environments, sensors can be placed at measurement points through long-distance optical fibers, and operators can collect and monitor data from a safe distance; This is also very suitable for difficult to access scenarios such as measuring the temperature of volcanic lava and measuring the water temperature near deep-sea geothermal vents.
No need for power supply (fiber optic cables themselves do not require power supply): The main source of energy is the light source, which is safe and convenient to use in environments that require explosion-proof or isolated power supply (such as oil and gas extraction sites, chemical raw material storage warehouses, and other flammable and explosive places, mỏ, vân vân.), avoiding potential hazards such as electric sparks that may be caused by power supply.
Diversity and flexibility of measurement points: By changing the number and position of fluorescent probes in the optical fiber, it is easy to achieve multi-point or distributed temperature measurement. In large-scale pipeline networks, buildings with wide coverage areas, vân vân., probes can be set up at multiple key locations according to demand for comprehensive temperature monitoring, increasing the flexibility and applicability of the system.
Corrosion resistance and high temperature resistance: Fiber optic materials have excellent corrosion resistance and high temperature resistance, and can be used in harsh environments, withstanding high temperatures, áp lực cao, and corrosive chemical substances. Maintain the normal temperature measurement function of sensors in high-temperature, áp suất cao, and highly corrosive environments such as the combustion zone of aerospace engines, around metal smelting furnaces, and inside chemical reaction vessels.
Ổn định lâu dài: The combination of fluorescent substances and optical fibers has high chemical and physical stability. Under long-term and uninterrupted monitoring requirements, such as temperature monitoring of offshore oil and gas platform equipment and environmental temperature monitoring station equipment in the Arctic region, nó có thể hoạt động ổn định trong thời gian dài, greatly reducing the frequency of maintenance and calibration, effectively saving costs and manpower.
Độ chính xác cao: Fluorescent substances respond quickly and have good repeatability to temperature, making measurement results more accurate in both rapidly changing temperature fields (such as temperature fluctuations in combustion reactions) and long-term stable temperature measurement requirements, ensuring high-precision data output.
Fast data transmission speed: Fiber optic transmission of data is extremely fast, especially important in extreme environmental systems that require rapid response. Ví dụ, temperature monitoring at the moment of rocket engine ignition, high-speed data transmission can provide timely feedback on temperature information for timely decision-making and adjustment; Real time or almost real-time temperature monitoring can be achieved.
Easy integration and automation: The fluorescence fiber optic temperature measurement system can be easily integrated with existing computer systems and automation equipment, facilitating the automation and intelligence of temperature monitoring. In some modern automated production factories, remote unmanned monitoring stations, vân vân., intelligent temperature management can be easily integrated into existing systems.
Good electrical insulation and explosion resistance: The fiber optic sensor used for fluorescence fiber optic temperature measurement is an electrical insulator that is non-conductive. Even in flammable and explosive environments, it will not generate electric sparks or static electricity, which can cause accidents. Vì thế, in extreme environments with explosive hazards such as chemical and oil and gas storage, its intrinsic safety is extremely high.

Cảm biến nhiệt độ sợi quang phân tán also have their unique advantages for extreme environments:

cách nhiệt: Optical fibers themselves are electrically insulated, vốn đã an toàn, and resistant to electromagnetic interference. This is of great significance in environmental monitoring of power systems, such as near large substations or high-voltage transmission towers. This insulation can prevent electrical accidents and ensure that temperature measurements are not affected by external electromagnetic interference, ensuring data accuracy. Cáp quang phân tán temperature sensors are capable of working in environments with electromagnetic interference risks, such as temperature monitoring of power facilities in areas with frequent lightning strikes or temperature monitoring of wind and photovoltaic power generation equipment during operation.
Giám sát từ xa: It can achieve distributed continuous real-time temperature monitoring over a long distance and a large range, accurately measuring the temperature value at any point along the fiber optic cable. In extreme environments with long-distance characteristics, such as temperature difference monitoring of the entire submarine fiber optic cable, temperature monitoring along multi kilometer or even tens of kilometers long oil pipelines or urban heating pipeline systems, it is possible to achieve full fiber coverage and obtain comprehensive temperature information, greatly reducing the complexity and cost of detection point layout.
Chống ăn mòn: The material used to make the fiber optic core is silicon dioxide, which endows the fiber optic sensor with excellent corrosion resistance and long service life. In highly corrosive marine environments, industrial wastewater discharge pipelines, and underground oil and gas pipelines, a large amount of corrosive media (such as seawater, acidic and alkaline solutions, vân vân.) are densely distributed. Distributed fiber optic temperature sensors can measure temperature stably for a long time without being eroded.
Strong flexibility: Optical fibers have excellent flexibility and flexible installation positions, which can meet the needs of different projects and installation positions. In environments with complex spatial layouts (such as small and irregular installation spaces for instruments and equipment inside spacecraft, and complex tunnel scenes in large water conservancy projects), optical fibers can be bent and arranged according to the actual spatial requirements, making it easier for sensors to accurately measure in extreme environments that are difficult to plan and layout. Temperature measurement in narrow spaces such as car engine compartments and airplane wings can also leverage this feature.
Obtaining multiple points of information at once: By measuring the entire fiber area in one go, a one-dimensional distribution map of the measured area can be obtained. By setting a special framework for the fiber (such as framing it into a grating shape), the two-dimensional and three-dimensional distribution of the measured area can also be determined. In large chemical storage tanks and buildings, it is necessary to conduct three-dimensional temperature field distribution detection (such as detecting the temperature distribution at different heights and areas in a large warehouse, using a three-dimensional fiber optic network to transmit and receive and measure the temperature at different locations), and overall temperature detection of the internal structure of large bridges, which can obtain multi-point and overall temperature information. This advantage is very obvious and can efficiently understand the temperature status of the entire monitoring space.
Suitable for various complex and extreme environments: Distributed fiber optic temperature sensors can adapt to various extreme environments. Ví dụ, in complex and diverse production scenarios in various industries such as chemical, điện tử, luyện kim, dược phẩm, vân vân., it can effectively work when measuring the thermal distribution field of large storage tanks storing flammable, chất nổ, gas or other substances. Hơn thế nữa, in large equipment such as boilers, máy phát điện, vân vân., it is difficult to install conventional sensors due to their complex structure, or conventional sensors cannot be approached due to strong electromagnetic interference, or the cost of point by point measurement is too high to be practical. Distributed fiber optic temperature sensors can play a prominent role in these extreme environments where traditional sensors are not suitable. Ngoài ra, good temperature monitoring results can be achieved in extreme scenarios such as temperature field distribution measurement in bridges, đập nước, ships, tòa nhà lớn, kho hàng, high-pressure vessels, đường hầm, and even aircraft and spacecraft bodies.

Basic Principles and Development of Distributed Fiber Optic Sensors

The principle of distributed cảm biến nhiệt độ sợi quang is to use the Raman scattering principle of fiber optic. When the temperature of a certain part of the fiber optic changes, the scattered light is affected. Through high-speed signal acquisition and data processing technology, the location of the disturbance can be accurately located and real-time temperature alarm information can be provided. At the beginning of its development, it started with Rayleigh scattering systems based on optical time domain reflectometry (OTDR), and went through Raman scattering systems based on OTDR and Brillouin scattering systems based on OTDR. This development process greatly improved the temperature measurement accuracy and range. Hiện tại, research on optical frequency domain reflectometry (OFDR) technology is also constantly deepening. Although there is still some way to go in terms of industrial practicality, it is still the development direction of distributed fiber optic temperature sensor technology. Với sự phát triển, Hiệu suất của toàn bộ cảm biến nhiệt độ sợi quang phân tán tiếp tục được cải thiện để thích ứng tốt hơn với các nhu cầu đo lường môi trường khắc nghiệt khác nhau.

Fiber Bragg grating temperature sensors cũng có nhiều ưu điểm phù hợp với môi trường khắc nghiệt:

Sóng mang tín hiệu độc đáo và lợi thế tương ứng: sử dụng bước sóng phản xạ làm sóng mang tín hiệu (tức là. điều chế bước sóng), nó không bị ảnh hưởng bởi sự dao động dòng điện và điện áp. So với các cảm biến truyền thống sử dụng dòng điện và điện áp làm sóng mang tín hiệu, chẳng hạn như cảm biến nhiệt độ dựa trên phương pháp đo điện truyền thống (chẳng hạn như máy dò nhiệt độ dựa trên điện trở kim loại) trong môi trường nhiệt độ cực thấp và từ trường mạnh, they cannot work due to the Kondo effect at ultra-low temperatures (causing a significant increase in temperature probe resistance), Hall effect under strong electromagnetic fields, and magnetoresistance effect (causing strong interference to the readings of most electronic components). Fiber Bragg grating temperature sensors completely avoid this drawback and can perform temperature measurements normally. This characteristic of using wavelength as a signal also has stability that matches its optical method. Even in complex optical interference environments or light source fluctuations, it can still detect wavelength drift caused by temperature changes relatively stably, thus enabling accurate temperature measurement.

Small and lightweight, suitable for distributed multi-point measurement: kích thước nhỏ, trọng lượng nhẹ, và dễ dàng tạo ra nhiều cách tử liên tục trong một sợi quang. Mảng lưới được sản xuất rất nhẹ và linh hoạt, and when combined with time-division multiplexing and wavelength division multiplexing technologies, it is very suitable as a distributed sensing element. It performs well in distributed multi-point temperature measurement of large areas or large-scale structures, such as the need to arrange numerous measurement points on the surface of the huge fuselage of an aerospace aircraft, and temperature monitoring at multiple points on the surface and inside of large superconducting equipment (maglev train superconducting components, particle accelerator superconducting components, vân vân.). After embedding or pasting inside or on the surface of the structure, multi-point temperature measurement can be achieved; This feature is also beneficial for reducing the complexity and weight burden of equipment when arranging multiple sensors, and has irreplaceable advantages for some cutting-edge applications that require strict weight requirements, such as sensor loads in aerospace exploration equipment.
Strong resistance to electromagnetic interference and corrosion: This is a common advantage of the fiber optic sensor family. This sensor can be widely used in extreme environments, whether it is for monitoring equipment temperature in high-temperature and high electromagnetic interference areas such as metal smelting factories, or for detecting temperature in some marine ship electrical equipment due to corrosion risks and electrical interference in the surrounding salt spray and humid environment. Stable operation can also be achieved in special extreme environments such as nuclear power, nơi có bức xạ điện từ mạnh và có nguy cơ ăn mòn tiềm ẩn (chẳng hạn như sự hiện diện của bầu không khí ăn mòn ở các đảo hạt nhân do các chất hóa học đặc biệt), như giám sát nhiệt độ đường ống hệ thống làm mát bên ngoài của lò phản ứng hạt nhân hay giám sát nhiệt độ của một số thiết bị điện bên trong nhà máy điện hạt nhân.
Ưu điểm về độ nhạy và tốc độ phản hồi: Cảm biến nhiệt độ cách tử sợi Bragg dựa trên khả năng phát hiện độ nhạy pha có thể đạt được độ nhạy cực cao ở mức milikelvin, điều đó có nghĩa là họ có thể phát hiện những thay đổi nhỏ về nhiệt độ (chẳng hạn như dao động nhiệt độ yếu gần độ không tuyệt đối, sự thay đổi nhiệt độ trong môi trường nghiên cứu cực kỳ vi mô như tế bào sinh học), making them suitable for precise measurement of small temperature changes. Đồng thời, it has a fast response time and can provide timely and accurate temperature data feedback in extreme scenarios where rapid temperature changes occur, such as changes in the temperature field around the detonation shock wave generated at the moment of an explosion experiment or sudden temperature changes on the surface of the irradiated object under high-energy laser irradiation. It also has broad application prospects in fields such as biomedical imaging, microfluidics, nanotechnology, which require extremely high reaction speed and measurement accuracy.

Comparison of the advantages of fiber optics solutions in extreme environments

Khả năng chống nhiễu điện từ
Cảm biến nhiệt độ sợi quang huỳnh quang: Dựa trên nguyên lý của sợi quang huỳnh quang, nó cách ly nhiễu điện từ một cách tự nhiên và có thể đảm bảo đo nhiệt độ chính xác mà không bị ảnh hưởng trong các tình huống khắc nghiệt như môi trường điện từ mạnh, nhà máy công nghiệp với nhiều thiết bị điện tử và môi trường điện từ phức tạp.
Cảm biến nhiệt độ sợi quang phân tán: Sợi quang có các đặc tính cơ bản là cách điện và khả năng chống nhiễu điện từ. Trong vùng điện từ mạnh liên quan đến điện (xung quanh trạm biến áp và đường dây tải điện cao thế), dữ liệu đo nhiệt độ ổn định, không có sự can thiệp hoặc sai lệch, và có thể theo dõi chính xác nhiệt độ trong xưởng sản xuất với số lượng lớn thiết bị điện tạo ra trường điện từ phức tạp.
Cảm biến nhiệt độ lưới sợi Bragg: Using wavelength as the signal carrier, it avoids electromagnetic interference in current and voltage, and can stably detect temperature in extreme scenarios with high-intensity electromagnetic fields (such as around large particle accelerators, near strong electromagnetic emission equipment, vân vân.).
In terms of extreme environmental resistance (nhiệt độ cao, áp suất cao, ăn mòn mạnh, vân vân.)
Cảm biến nhiệt độ sợi quang huỳnh quang: The fiber optic material is corrosion-resistant and high-temperature resistant, and can penetrate deep into industrial furnaces at high temperatures for temperature measurement up to several hundred degrees Celsius; Work normally in environments with corrosive chemicals, such as chemical reaction vessels and acid storage tanks; Suitable for temperature monitoring in high-pressure environments (such as temperature monitoring near high-pressure hot springs in deep sea).
Cảm biến nhiệt độ sợi quang phân tán: The fiber optic material is corrosion-resistant silicon dioxide, which can continuously monitor temperature in corrosive environments of chemical wastewater pipelines and around underground pipelines in saline alkali areas for decades of service life; Effective in monitoring the temperature along large high-temperature steam transmission pipelines in scenarios where high-temperature oil generates heat and pressure in long-distance oil pipelines; It can also be used in scenarios such as aircraft and spacecraft bodies that require temperature monitoring while experiencing high-altitude pressure changes.
Cảm biến nhiệt độ lưới sợi Bragg: With its miniaturized integrated design, it can be attached to the surface of high-temperature components (for monitoring the surface temperature of aviation turbine engine blades) để đo lường; Using fiber Bragg grating sensors made of special materials to solve high temperature and ultra-high temperature measurement (such as sapphire fiber Bragg grating sensors that can measure high temperatures up to 1600 oC); Temperature measurement can also be carried out on outdoor electrical equipment in harsh marine climate environments with corrosion risks (external motor temperature of offshore wind power generation equipment).

Measurement dimensions and flexibility
Cảm biến nhiệt độ sợi quang huỳnh quang: By adjusting the arrangement of the fluorescent probe, point to multipoint measurement can be achieved, thereby meeting the temperature measurement needs in different spaces and flexible layout requirements. It can also balance small-scale local temperature monitoring and large-scale distributed point temperature monitoring. Ví dụ, when arranging temperature monitoring points for different production line equipment in a factory building, the position of fluorescent probes can be freely set according to the distribution of equipment to create or adjust the temperature monitoring layout.
Cảm biến nhiệt độ sợi quang phân tán: The entire fiber optic line can be regarded as the sensing area, which can complete long-distance continuous measurement at once. It has natural distributed measurement characteristics, especially can easily form a fiber optic network for temperature monitoring in two-dimensional or even three-dimensional areas (such as three-dimensional warehouses and multi story buildings). Hơn thế nữa, the flexibility of optical fibers allows for installation positions to be unrestricted, and can be arranged between channels or equipment of different shapes and directions according to specific environments to obtain temperature values.
Cảm biến nhiệt độ lưới sợi Bragg: Multiple gratings can be integrated on a single optical fiber to achieve multiple measurement points. Tuy nhiên, compared to the above two, the density of measurement points per unit fiber length can theoretically be higher. Through wavelength division multiplexing and time-division multiplexing technology, the temperature of each grating point can be measured in time or simultaneously. It is more suitable for fields with precise spatial layout (such as narrow internal space of optical instruments and biomedical micro samples requiring multi-point accurate temperature measurement), and due to its lightweight and flexibility, it also has great flexibility in attachment and embedding.
Cost and application popularization aspects
Cảm biến nhiệt độ sợi quang huỳnh quang: It has achieved large-scale industrial production and application, with rapidly decreasing costs. Hiện nay, it is widely used in medical diagnosis, quản lý năng lượng, và các lĩnh vực khác. With the expansion of popularity and technological upgrades, there is still room for cost reduction, making it easy for new users to choose and adopt. Introducing this sensor through infrastructure renovation does not require particularly huge cost investment.
Distributed fiber optic temperature sensors have been widely used in large-scale engineering projects (such as health monitoring of large bridge structures and long-distance pipeline temperature monitoring systems) and specific industrial scenarios (such as power plants and substation monitoring). Although its technology has developed maturely, it is hindered in the popularization of some small or cost sensitive projects due to relatively high initial investment in measurement hosts and supporting equipment, fiber optic laying, vân vân. Tuy nhiên, with the promotion of technology, advances in materials, and the improvement of equipment integration, its application cost is also expected to decrease.
Cảm biến nhiệt độ lưới sợi Bragg: It is widely used in high-end equipment manufacturing fields such as aerospace and large ship manufacturing, and also has a certain proportion of micro applications in biomedical research. Due to the limitations of fiber Bragg grating technology, especially the preparation technology of special materials such as sapphire fiber, which is mastered in a small number of units and has high costs, such as complex preparation processes and special grating writing conditions, the overall cost is high. Hơn thế nữa, many high-end applications still rely on imported components. If we want to apply them in general industrial scenarios or large-scale promotion of basic monitoring fields like the previous two, there are still significant cost barriers.