Quick Facts
In order to prevent fires and failures, optical fiber sensors are widely used in various fields such as optical cable operation and maintenance, oil and gas pipeline networks, power systems, and public transportation, gradually forming a pattern of close integration of production, education and research.
The traditional optical fiber sensing technology is difficult to meet the development trend of "large capacity, high precision, high density, long distance and high reliability" of optical fiber sensing network.
Driven by the market in the main application fields of optical fiber sensing technology and its own technology, the market scale of the industry continues to rise and has broad development prospects.
01 Downstream application accidents are high, and optical fiber sensing technology is promising
1) Fires and accidents caused by faulty electrical cables
On November 9, the National Fire and Rescue Administration released the national fire situation report from January to October 2023. From January to October this year, a total of 74 fires were reported across the country50,000 cases, 1,381 people died, 2,063 people were injured, and 61 direct property losses were verified500 million yuan, compared with the same period last year, the number of cases and the number of injuries increased by 25% and 65%。Among them, a total of 21 were caused by electrical-caused fires70,000 cases, the fires killed 418 people, accounting for 30 of the total3%, direct property loss 26300 million yuan, electrical failure is the primary cause of fire.
In addition to fire, with the rapid growth of optical cable laying area and intensity, as well as the rapid growth of China's oil and gas pipeline network and power system, there are also many difficulties in its operation and maintenance management, such as large monitoring workload, large fault location error, imperfect performance monitoring and other problems. According to relevant statistics, more than 85% of the network and electricity unavailability events are caused by cable failures, which has caused great losses to economic and social life.
In order to prevent the occurrence of fires and reduce the losses caused by cable failures, scientific and technological personnel continue to explore and develop new early warning technologies. Among them, optical fiber sensing technology, as an emerging technical means, has been widely used in fire early warning and optical cable monitoring, and has achieved important results.
2) Fiber optic sensing technology
Sensing technology is an important part of modern information technology, optical fiber sensing is a new type of sensing technology that uses light as the carrier of information, optical fiber as the medium of propagation and sensing, and obtains useful information by analyzing the changes of optical signals in the sensing fiber.
As the most rapidly developing branch in the field of modern sensing, optical fiber sensing has many unique and excellent properties, such as small size, light weight, corrosion resistance to high temperature and other harsh environments, anti-electromagnetic interference, large information capacity, high sensitivity, etc., and can achieve large-scale and long-distance signal detection through multiplexing technology arrays or distributed structures. Therefore, optical fiber sensing technology is particularly suitable for long-term measurement in harsh environments, turning passive inspection into active perception, realizing digital and intelligent monitoring and operation and maintenance, and has incomparable advantages over traditional electromagnetic sensors.
3) Application scenarios of optical fiber sensing technology
After years of academic research and technological development, optical fiber sensing technology has formed a trend of accelerated development in recent years, and has extensive scientific research in the measurement of temperature, pressure, sound waves, vibrations, magnetic fields, strains and many other physical quantities, and has been widely used in a number of practical scenarios and interdisciplinary fields, such as electric power, petroleum, chemical industry, transportation, biology, medical treatment, etc., and has gradually formed a pattern of close integration of production, education and research. Typical applications are as follows:
Optical cable operation and maintenance management
In the process of construction and service of optical cables, due to technical and environmental impacts, it is inevitable that there will be bad torsion and physical damage, and fault status monitoring and early warning are required. Although optical networks have protection measures for the active/standby paths of logical links, if the active/standby paths are on the same physical optical cable, the risk of service interruption caused by fiber disconnection accidents will greatly increase. The "co-routing detection" technology based on optical fiber sensing can realize the fusion management of optical cable pipeline information and service routing information.
Oil and gas pipeline network monitoring
China has a huge oil and gas pipeline network, according to the National Energy Administration, by 2025, the scale of the national oil and gas pipeline network will reach 210,000 kilometers. The oil and gas pipeline network has the characteristics of long span, complex geographical and geological environment, and most of them are in unsupervised areas in the field, and it is difficult for traditional monitoring methods to meet the safety monitoring requirements of oil and gas pipelines. Based on optical fiber sensing technology, the communication optical cable laid in the same trench of oil and gas pipelines and the intelligent analysis algorithm can realize real-time monitoring of long-distance pipelines with high spatial resolution and multi-parameter measurement.
Power line monitoring
The scale and transmission capacity of China's power grid rank first in the world. The stable operation of transmission lines is susceptible to the influence of environmental factors such as bad weather such as strong winds, thunderstorms, ice and snow disasters, and the traditional monitoring plan mainly relies on manual inspection, electronic point sensors and other methods, which have problems such as high labor intensity, high cost, difficult installation and maintenance, and difficult coverage of large areas. Optical fiber sensing technology can realize long-distance and real-time monitoring of a variety of parameters along the line, and has the advantages of fast response, strong anti-interference, high reliability, light weight and miniaturization compared with traditional methods.
The figure below shows a pilot of icing monitoring on a line of State Grid based on the distributed optical fiber sensing monitoring system in Accelink station, which can realize continuous real-time monitoring of the icing thickness of OPGW fiber optic cable by pitch.
Geological environment and fire monitoring and early warning
Based on optical fiber sensing technology and China's extensive coverage of optical communication network, a geological environment monitoring and early warning network including plains, mountains, rivers and oceans can be constructed. Through the analysis of optical signals and the detection of vibration and other parameters, on the one hand, it can monitor abnormal changes in the geological environment in real time, and provide early warning and risk assessment of **, landslides, debris flows, etc., so as to take appropriate protective measures;On the other hand, the changes of geological parameters, such as crustal displacement, water level changes, and geotechnical structure deformation, can be obtained in real time to assist in evaluating the safety and stability of the structure.
Perimeter security monitoring
The rapid development of social economy has put forward higher security requirements for important strategic areas such as nuclear power plants, railways, hazardous chemical warehouses, military bases, office areas, important infrastructure facilities, and large network nodes. The perimeter security system based on optical fiber sensing can effectively overcome the shortcomings of the traditional security system such as blind spots, performance deterioration, high false alarm rate, and lightning strikes, and has the advantages of long monitoring distance, no electromagnetic radiation, strong anti-interference ability, high reliability, and low operating cost.
Submarine cable monitoring and early warning
In addition to the monitoring of the geological environment mentioned above, its typical application scenarios include the effective monitoring of submarine cables, optical cables and related infrastructure, such as the monitoring and early warning of submarine trawl activities, ship anchoring, dredging activities, vortex-induced vibration, electrical faults, partial discharge, etc.
02 The sensor network is developing towards high precision, and the new array grating fiber may become the optimal solution
1) Several common fiber sensing technologies
Unlike traditional sensors, which are independent individuals, fiber optic sensors can connect multiple sensing units in series on a single fiber to form a monitoring network. According to the differences in the layout design of sensing units, optical fiber sensing technology can be divided into three categories: single-point, quasi-distributed and distributed.
Single-point fiber optic sensing
Single-point optical fiber sensors generally realize the acquisition of information in local areas, mainly including fiber grating sensors, optical fiber microstructure interferometry sensors, optical fiber spectral absorption sensors, and micro-nano fiber sensors. These sensing units can realize the sensing measurement of single or even multiple physical parameters, such as stress, vibration, refractive index, temperature, etc.
Among them, fiber grating (FBG) is a common point sensor. FBG is a method (such as ultraviolet engraving) to produce a periodic distribution of the refractive index of the fiber core of the optical fiber, which is selective to wavelength, and can reflect light of a specific wavelength and make other light pass through. FBG sensor has become one of the most rapidly developing sensors in recent years due to its advantages of high sensitivity, anti-electromagnetic interference, corrosion resistance, wide dynamic measurement range, small size, strong stability and easy reuse.
Quasi-distributed fiber optic sensing
Quasi-distributed optical fiber sensing technology connects multiple sensing units in series through optical fibers to achieve single-fiber long-distance and large-capacity sensing monitoring. The sensing units used to construct a quasi-distributed sensor network mostly use fiber grating, fiber optic FPI and fiber optic interferometer, which themselves have a high signal-to-noise ratio, and at the same time maintain the advantages of distributed sensing in networking and signal transmission. Using the characteristics of light waves, a quasi-distributed sensing network is formed on a single or multiple optical fibers through wavelength division multiplexing, time division multiplexing, frequency division multiplexing, space division multiplexing and hybrid multiplexing technologies.
Distributed fiber optic sensing
Distributed optical fiber sensing technology is an important part of the field of optical fiber sensing, which integrates transmission and sensing, and can realize the information acquisition of up to one million measurement points on the sensing optical fiber link, and realize large-scale and long-distance sensing monitoring. The distributed optical fiber sensing technology has no blind spots, and breaks through the limitation of the number of fiber grating demodulation and multiplexing sensing units and the limitation of spatial resolution, so it is called distributed measurement. At present, distributed optical fiber sensing systems have been widely used in many fields such as perimeter security, pipeline security, resource exploration, structural health monitoring, and medical testing, showing excellent engineering prospects.
2) The development trend of optical fiber sensing technology
At present, the new optical fiber sensing network characterized by "large capacity, high precision, high density, long distance and high reliability" has become the most important development trend of optical fiber sensing
Large capacity: It represents thousands or even tens of thousands of optical fiber sensing units
High accuracy: It represents a further significant improvement in the accuracy of optical fiber sensing monitoring
High density, which means that the sensing unit spacing will reach the centimeter level;
Long-distance, which means that the monitoring range of optical fiber sensing is up to tens or even hundreds of kilometers;
High reliability means that it can better meet the needs of long-term reliable operation of harsh engineering sites.
However, the traditional optical fiber sensing technology, whether it is fiber grating sensing technology or distributed optical fiber sensing technology, is difficult to meet the application needs and urgent needs of "large capacity, high precision, high density, long distance, and high reliability" optical fiber sensing network. Therefore, a new generation of optical fiber sensing technology based on grating arrays has emerged.
3) Grating fiber array sensing may be the optimal solution
With the sustained and stable development of China's economy, urban rail transit, highways, airports, oil and gas pipelines, large bridges, high-speed railways and other national large-scale projects and important infrastructure have shown a rapid growth trend.
The above-mentioned large-scale infrastructure and major projects are closely related to the safety of people's lives and property, and their operation status monitoring and safety management have become major problems that need to be solved urgently. In the face of the operation status monitoring and safety management needs of large-scale infrastructure and major projects in the fields of complex large transportation and security, traditional optical fiber sensing and other sensing technologies such as fiber grating sensing technology and distributed optical fiber sensing technology cannot meet the development needs of the above application fields due to their respective technical shortcomings.
The new generation of optical fiber sensing technology based on grating optical fiber, grating fiber array sensing, can be written into the fiber grating by drawing tower, and the massive sensing signals are demodulated by using wavelength division + time division hybrid multiplexing, effectively integrating the respective advantages of "fiber grating sensing technology" and "distributed optical fiber sensing technology", and then realizing a new generation of optical fiber sensing network with "large capacity, high precision, high density, long distance and high reliability". Chinese enterprises, such as Anhui Longlian Intelligence, have begun to lay out this new type of optical fiber sensing intelligent system, and have achieved certain results.
The emergence of new grating fiber array sensing technology can provide a complete and advanced solution for the state monitoring and safety management of national large-scale projects and important infrastructure in the fields of large transportation and security in China. The real-time condition monitoring and safety management needs of downstream markets such as high-speed railways have significantly improved the real-time monitoring capabilities and safety management level of China's large-scale infrastructure.
03Driven by technology, the optical fiber sensing industry has broad development prospects
The overall market size of China's fiber optic sensing solutions
In the first part, we mentioned that at present, optical fiber sensing technology has been widely used in power grid infrastructure, urban pipe corridors, oil and gas energy infrastructure, submarine cables, transportation infrastructure, urban security and other fields to achieve asset monitoring, operation and maintenance management functions, and the downstream application fields are very broad.
And according to Frost &Sullivan's statistics and **, in 2021, the market size of China's optical fiber sensing solutions will reach 729 billion yuan, with a compound annual growth rate of 271%, the rapid development of investment in power grid infrastructure, urban pipe corridors, oil and gas energy infrastructure, submarine cables, and other industries is the major growth factor driving the overall optical fiber sensing market. **By 2026, the market size will reach 2087 billion yuan.
2) Optical fiber sensingThe process of domestic substitution has been accelerated
At present, foreign companies engaged in optical fiber sensing technology mainly focus on product sales, and focus on the power industry, oil exploration and perimeter security in the Chinese market. Relatively speaking, the domestic enterprises engaged in optical fiber sensing technology are small, mainly focusing on product sales combined with engineering services, and the products are widely used in petroleum and petrochemical, electric power, transportation and other fields.
In recent years, domestic technology research and development enterprises with years of technology accumulation and market development, is gradually narrowing the gap with imported products, has been in the high-end market with foreign manufacturers to compete directly, and steadily replaced part of the market share occupied by foreign products.
Driven by technology, the industry has broad development prospects
With the rapid development of sensing technology, information technology and Internet technology, optical fiber sensors and intelligent instrumentation using new materials, new mechanisms and new technologies have achieved high sensitivity, high adaptability and high reliability, and are developing in the direction of multi-functional, miniaturization, modularization, intelligence, integration and networking. The market drivers for the main application areas are as follows:
Power Grid Industry
According to the plan, the State Grid will promote the construction of the power Internet of Things in two stages: 2019-2021 is the strategic breakthrough period, which will focus on the application of new technologies such as artificial intelligence, Internet of Things, and cloud computing to improve the power grid IoT and depth perception capabilities, and initially build the power Internet of Things in 2021Through three years of upgrading, the power Internet of Things will be built in 2024.
Offshore wind industry
According to the Global Wind Energy Association, China's new offshore wind power capacity was 16.9 million kilowatts in 2021, compared to 165 kW in 201850,000 kilowatts have achieved a substantial increase, and China's installed offshore wind power capacity has reached the first place in the world. From 2018 to 2021, the trend of new installed capacity of offshore wind power in China is shown in the figure below
Comprehensive pipe gallery
With the advancement of the process of urban modernization, the first department attaches more importance to the development of urban infrastructure construction, and the importance of the construction and management of the comprehensive pipe gallery in the urban infrastructure is gradually reflected, and it also provides more space for the application of optical fiber sensing system in the fields of pipe gallery body monitoring, tunnel environmental monitoring, and pipe gallery asset management.
Petroleum and petrochemical
The petroleum and petrochemical industry has high requirements for safety management, and sudden equipment failure may lead to unplanned shutdown of equipment and lead to safety production accidents. The stable operation of various types of key equipment is the cornerstone of the safe production of petrochemical enterprises, and petroleum and petrochemical enterprises need to install asset monitoring and operation and maintenance management systems on key equipment to monitor and diagnose temperature, stress, vibration, etc.
Urban Intelligent Transportation
According to the data of the Prospective Industry Research Institute, from 2011 to 2020, the total size of China's intelligent transportation market increased from about 4200.0 billion yuan increased to about 165.8 billion yuan, showing a clear upward trend, with an annualized growth rate of nearly 20%, showing a stable growth trend. It is estimated that by 2026, the market size of China's intelligent transportation industry will exceed 4,0000 billion yuan, with an average annual compound growth rate of about 16%. The rapid development of the urban intelligent transportation industry provides a broad market space for the application of optical fiber sensing systems in traffic signal control, fire monitoring, tunnel temperature monitoring, stress monitoring and other fields.
In the future, the development trend of miniaturization, intelligence and networking of optical fiber sensing and instrumentation technology will achieve reliable, accurate and ubiquitous network sensing. Various instruments and sensors can intelligently identify and perceive objects such as power grids, transportation, dams, and oil and gas pipelines, forming an Internet of Things of collaborative sensing, ubiquitous perception, and intelligent perception, and promoting the development of Internet of Things applications. As the basic components of the sensor network, optical fiber sensors and intelligent instrumentation will be integrated into the development of the Internet of Things industry, and will have a very broad market prospect in the future.
04 Epilogue
With the progress of FBG array sensing technology and the continuous emergence of research results, it has become more and more important in the field of sensors. It is widely used in civil engineering structures, aerospace industry, shipbuilding and shipping industry, power industry, petrochemical industry, medicine, nuclear industry, etc. A lot of practical technology research with development potential and market prospects is being carried out.
Looking to the future, there is still room for further improvement and improvement of fiber optic sensing technology. For example, we will continue to promote the engineering and practical application of optical fiber sensing technology, starting from market logic, demand drives the market, and the market drives technological progressSolve the engineering problems of optical fiber in many fields such as medical biology, resource exploration, military and national defense, so that optical fiber sensors can gradually approach or even replace traditional electromagnetic sensors on the basis of maintaining their own unique advantages, and realize technological revolution. The maturity and improvement of these technologies will give a tremendous impetus to the construction of the national economy.