Fiber optic temperature measurement technology is a recently developed temperature measurement technology suitable for high-voltage equipment. Unlike other traditional temperature measurement methods such as wireless temperature measurement, infrared temperature measurement, thermocouple testing, etc., fiber optic temperature measurement has advanced temperature measurement advantages. However, like other new technologies in fiber optic sensors, fiber optic temperature measurement technology is not everything that can be achieved. It is not intended to completely replace traditional temperature measurement methods, but rather to supplement and improve traditional temperature measurement technology. Fiber optic sensor technology can fully leverage its characteristics in new applications, creating new fiber optic temperature measurement solutions and technological applications.
Application scope of fiber optic temperature measurement technology
Temperature measurement under strong electromagnetic field
High frequency and microwave heating methods have received attention and are gradually expanding into the following fields: high-frequency melting of metals, welding and quenching, vulcanization of rubber, drying of wood and fabrics, as well as pharmaceuticals, chemicals, and even home cooking. Fiber optic temperature measurement technology has absolute advantages in these fields because it does not have additional heating caused by conductive parts and is not affected by electromagnetic fields.
Temperature measurement of high-voltage electrical appliances
The most typical application is temperature measurement of the winding resistance hot spot of high-voltage transformers, to ensure that the transformer is in the optimal power distribution state. Another type of application is in various high-voltage devices, such as generators, high-voltage switches, overload protection devices, and even overhead power lines and underground cables.
The production process of flammable and explosive materials and temperature measurement of equipment
Fiber optic sensors are essentially fire-resistant and explosion-proof devices, which do not require explosion-proof measures and are very safe and reliable. Compared with electrical sensors, it can reduce costs and improve sensitivity. For example, the reaction tank in a large chemical plant operates in a high-temperature and high-pressure state. Real time monitoring of the surface temperature characteristics of the reaction tank can ensure its correct operation. By laying optical fibers along the surface of the reaction tank into a temperature sensing grid, any hot spot can be monitored, which can effectively prevent accidents from occurring.
Introduction to Fluorescence Temperature Measurement Technology
Fiber optic temperature measurement technology has been widely applied in the field of temperature sensing technology in recent years. Unlike traditional temperature measurement methods, fiber optic temperature measurement can directly measure the temperature of hotspots through a sensing probe placed on the measured point in a complex electromagnetic environment, providing users with direct and dynamic measurement. It has the advantages of direct, real-time, and accurate measurement. The measurement and signal transmission of sensitive components in the fiber optic temperature measurement system are completed by fiber optics, without the introduction of electrical signals. It is very suitable for direct temperature measurement in high voltage and strong magnetic field environments, while ensuring the insulation performance of the original high-voltage environmental device.
The fluorescence fiber temperature sensing technology based on the principle of fluorescence afterglow has unique advantages such as large measurement range, stable performance, simple topology structure, and long service life. It is an important development direction in the field of fiber optic temperature measurement and has a very broad prospect.
The working principle of fiber optic fluorescence temperature sensor
Fiber optic fluorescence temperature sensor is currently a new type of temperature sensor that is actively researched. The working mechanism of fluorescence temperature measurement is based on the basic physical phenomenon of photoluminescence. The so-called photoluminescence is a phenomenon of light emission, which occurs when a material is excited by light in the ultraviolet, visible, or infrared regions. The fluorescence parameters emitted have a one-to-one correspondence with temperature, and the required temperature can be obtained by detecting their fluorescence intensity or fluorescence lifetime.
The intensity type fluorescent fiber optic sensor is affected by the micro bending, coupling, scattering, and back reflection of the fiber, causing intensity disturbances and making it difficult to achieve high accuracy. Fluorescence lifetime type sensors can avoid the above drawbacks, so they are the main mode used, and the measurement of fluorescence lifetime is the key to temperature measurement systems. Fiber optic fluorescence temperature sensors have their own unique advantages compared to other fiber optic temperature sensors: due to the inherent relationship between fluorescence lifetime and temperature, which is independent of light intensity, self aligning fiber optic temperature sensors can be made. However, general fiber optic temperature sensors based on light intensity detection require frequent calibration due to the fact that the optical transmission characteristics of the system are often related to transmission fibers and fiber couplers.
The characteristics of fiber optic temperature sensors
Fiber optic temperature sensors have many advantages compared to traditional temperature sensors:
1. Light waves do not generate electromagnetic interference and are not afraid of electromagnetic interference;
2. Easy to be received by various optical detection devices, and can easily perform photoelectric or electro-optic conversion;
3. Easy to match with highly developed modern electronic devices and computers;
4. Fiber optic has a wide operating frequency and a large dynamic range, making it a low loss transmission line;
5. The optical fiber itself is not electrified, has a small size and light weight, is easy to bend, and has good radiation resistance. It is particularly suitable for use in harsh environments such as flammable, explosive, strictly limited space, and strong electromagnetic interference.
Composition of Fluorescent Fiber Temperature Measurement System
The fluorescence fiber temperature monitoring system is a new type of fluorescence fiber temperature measurement fire monitoring system developed based on fluorescence fiber temperature sensing technology. The system consists of fiber optic temperature demodulator, temperature measuring fiber optic probe, transmission fiber optic, monitoring host, and fiber optic temperature measurement software.
The fiber optic temperature measurement sensor system is specifically designed to ensure the safe operation of high-voltage power equipment (such as transformers, switchgear, cable joints, capacitors) in power plants, substations, and industrial and mining enterprises. When these key equipment are used for a long time, overloaded, insulation aging, or poor contact, local overheating will occur. By monitoring the temperature at multiple points inside the equipment in real-time, possible faults can be predicted, effectively preventing accidents from occurring.
The characteristics of fluorescence temperature measurement system in the application of power equipment
(1) FJINNO has achieved independent research and development and production of fiber optic temperature measurement devices, with mature technology and high degree of application, which have been widely used in large power enterprises;
(2) Embed the fluorescent fiber optic temperature sensor probe into the tested equipment and use the fiber optic as the medium for temperature sensing signal propagation. It has good insulation performance, strong resistance to electromagnetic interference, and fast response speed;
(3) Under high voltage and high magnetic field conditions, it is possible to achieve online and real-time accurate measurement of the hot spot temperature of the winding, effectively overcoming the inherent shortcomings of traditional temperature measurement methods such as inability to directly measure hot spot temperature, poor electromagnetic immunity performance, and poor accuracy. It can provide effective and reliable operational status information and decision support for the operation department in complex electromagnetic environments such as transformers in a timely manner, and improve the reliability of power system operation;
(4) Fluorescent fiber optic temperature sensors can easily achieve integrated structural design with the transformer body, simplify the secondary information transmission circuit, and improve the integration degree between intelligent components and the transformer body.
The application scope of fluorescence fiber optic temperature measurement system
Temperature measurement for rail transit
Electrical fire warning and monitoring system (power plants, substations, industrial and mining enterprises)
Application in the power industry
Online Monitoring of Hotspot Fluorescent Fiber Optic Temperature in Oil Immersed Transformer Windings
Hot spot fiber optic temperature measurement for switchgear
Please contact FJINNO for the specific application scope and price of fiber optic temperature measurement.