Electricity is the most widely used secondary energy in modern society, and the power industry is an important basic industry and public utility related to the national economy and people's livelihood. It goes without saying that the sensor is equivalent to the visual nerve of the power industry, and it is an important guarantee for the safe and reliable operation of electricity and the stable supply of quality and quantity.
In the process of electric power production, temperature measurement and control are very important. Accurate measurement of temperature parameters is essential for the output quality, production efficiency and safe and reliable operation of electric energy. At present, in the process of power production and maintenance, non-traditional temperature sensors such as advanced infrared thermometers have been gradually adopted to replace the traditional thermocouple temperature sensors of thermocouples and thermal resistors, thereby realizing the production process of electric power or important equipment. Temperature monitoring and control.
Principles and advantages of infrared temperature sensors
Infrared radiation, commonly known as infrared, refers to electromagnetic waves with a wavelength in the range of approximately 0.75-1000 mm. The physical essence of infrared radiation is heat radiation. When the temperature of an object is above absolute zero, the thermal motion of the charged particles inside will emit infrared rays. The higher the temperature of the object, the more infrared radiation will be emitted and the stronger the energy of the infrared radiation. The infrared thermometer is based on the energy of the infrared radiation of the object and its wavelength distribution, and the corresponding relationship with the surface temperature of the object, and accurately measures the surface temperature of the object by measuring the infrared energy radiated by the object itself.
Compared with conventional temperature sensors such as thermocouples and thermal resistors, infrared thermometers have many advantages such as wide temperature measurement range, long life, reliable performance, extremely fast response and non-contact. In addition, infrared thermometers are also particularly suitable for measuring the temperature of corrosive media and moving objects without damaging the temperature field of the object being measured.
In recent years, with the rapid development of microprocessor chips and infrared temperature sensing technology, the performance of infrared temperature sensors has been continuously improved, and its application range can cover different sections of low, medium and high temperature.
Medium and low temperature infrared temperature sensor in electrical facilities and process measurement and control
The PyroCoupleM series of miniature infrared temperature sensors produced by Calex Electronics of the United Kingdom have a temperature range of -20 ° C to +500 ° C, an accuracy of ±1% of the reading, a repeatability of ±0.5% of the reading, and a response time of 200 ms. It has an IP65 protection rating and can be used in environments with an ambient temperature range of 0°C to 70°C and a relative humidity of 95%, and can output current, voltage or thermocouple signals. In power plants, it is mainly used to measure the temperature of boiler air preheaters, bus bars, important circuit breakers, motor bearings, motor windings, transformer windings, UPS or other electrical joints in a non-contact manner, and is used to detect hot spots of equipment in time. Or connection faults, etc., to provide diagnostics, status maintenance and maintenance of electrical systems or equipment.
Fluke's new CM series of small integrated infrared thermometers from Fluke, whose output signal is 0-5V or J, K type thermocouple continuous signal and switch alarm contact signal, and RS232 digital communication Interface, probe status and self-diagnostic display LEDs for continuous temperature monitoring in industrial manufacturing processes. In the case of large electromagnetic interference in the field, it can be used to replace common thermocouples and thermal resistors that are susceptible. The thermometer has a fast response time of up to 150ms, which enables real-time monitoring of the temperature of the trapline, the temperature difference of the hydrophobic bag and the detection of the water in the pumping line. It can fully meet the preventive water protection of the power plant and the rapid detection. Response time and reliability requirements.
Infrared pyrometer in furnace applications
Generally, an infrared thermometer measuring high temperature (above 700 ° C) has a useful wavelength band mainly in the near-infrared region of 0.76 to 3 mm, and optical materials for transmission are mainly optical glass or quartz.
The Marathon series of infrared thermometers produced by Raytheon are industrial grade products designed for harsh industrial environments. The temperature range is -40 ° C ~ 3000 ° C. This infrared moisture meter has a high performance optical lens. With an optical resolution of up to 300:1 and response times of 2ms, 60ms and 120ms, it is IP65 rated to prevent contamination and damage during installation, setup and use. And with standard analog, digital and distributed relay outputs, it can simultaneously transmit data, alarm triggers and control signals. Built-in smart circuit box and easy to use operator interface. In addition, the infrared thermometer's rugged stainless steel housing ensures safe operation in demanding industrial environments.
Through the temperature of the boiler furnace and the rear furnace zone of the power plant, not only the combustion intensity of the fuel inside, but also the efficiency of the combustion process can be directly reflected, and the heating surface of the boiler and the subsequent process can be indirectly affected (such as Normal operation of denitration, ash control, etc.) From the point of view of the safety control and efficiency of the power plant, the temperature in the furnace zone is very important and requires the key parameters of the operation monitoring. In Europe, a considerable number of power plant or boiler manufacturers (such as the French Stein boiler) use the above-mentioned type of infrared optical pyrometer to measure the temperature of the flue gas in the large boiler section and thereby achieve the full furnace of the boiler. Flame detection and protection of hearth fires.
Application advantages of infrared imager
In a power plant, the operation or maintenance personnel not only need to know the average temperature of the surface of the controlled object, but also need to know the distribution of the temperature field of the monitored object in order to analyze and study whether the operation is normal and whether the internal structure is defective. Different from the point-type infrared temperature sensor described above, the infrared imager adopts the surface temperature measurement method, which can visually display the temperature field distribution of the object in image form to meet the needs of temperature field monitoring.
The infrared imager mainly detects the radiation amount in the infrared electromagnetic spectrum region with the wavelength range of 0.9 to 14 mm, and gives the temperature value and temperature field distribution map of the heat radiator through thermal image technology, and converts it into a visible thermal image. Most imagers do not use conventional CCD or CMOS sensing elements, but instead use a special FPA (focal plane array) to sense longer wavelength bands. The most commonly used FPAs are InSb, InGaAs, HgCdTe and QWIP. Currently, the world's most advanced infrared imager has a temperature sensitivity of up to 0.03 °C.
When the infrared camera is actually used, it is only necessary to input the relevant parameters such as the thermal range, the heat level, the atmospheric temperature, the ambient temperature, the emissivity of the measured object, and the measurement distance into the meter embedded computer, and the automatic drawing can be automatically obtained. Temperature distribution and other results.
Infrared imager can quickly and accurately detect the loose or poor contact of the electrical equipment, load imbalance, overload, overheating and other hidden dangers (the potential hazard of these hidden dangers is arcing, short circuit, equipment fire or burning, resulting in more brewing Serious accident or fire, etc.). For all devices that can be seen directly, the infrared imager is able to determine the thermal hazard of all connection points, and for those parts that cannot be directly seen due to obscuration, the potential can be found based on the conduction of heat to the outer part. Hidden dangers. In this case, there is no better way to do the traditional detection method than disintegration. It can be seen that the role of the infrared imager is irreplaceable in the operational testing of circuit breakers, conductors, bus bars and other components.
In addition, the infrared imager can easily detect the imbalance of the transmission or power supply circuit or the imbalance of the three-phase load.
Dry Back - Glue Down,Waterproof Vinyl Glue Down Floor,Waterproof Luxury Vinyl Floor,Textured Luxury Vinyl Plank Flooring
Changzhou Yingda New Material Co., Ltd , https://www.yingdaspc.com