Abstract:In petrochemical industry, elevated flares are the important devices to burn off the waste gas from upstream processes. However, there often exist incomplete combustions during flare operations. These are mainly manifested as two forms: (1) unburned volatile organic compound (VOC) emission due to low heat values in the combustion zone; (2) smoke or soot emission due to insufficient air supply. In recent years, the flare industry has made an attempt to use optical methods on flares to monitor their combustion conditions. Several optical monitoring technologies including passive Fourier Transform Infrared (PFTIR) spectroscopy, mid-infrared hyper-spectral imagery, sky-light line-of-sight attenuation (sky-LOSA) and dual wavelength infrared sensor used in flare industry are presented. Their operating principles, applications and developments are discussed. Finally, the development trend and application prospect of remote optical monitors in the field of elevated flares are analyzed.

Abstract:Wire bonding is one of the key technologies of infrared detector packaging. However, the choice of wires may directly affect the electrical, mechanical and thermal properties of infrared detector modules. Because material, material diameter, material length and lead process need to be considered in wire interconnection, a variety of wires are usually used to meet different demands in the packaging of infrared detectors. The electrical, mechanical and thermal properties of the wires of infrared detector modules are presented systematically. The burn-out current of gold wire, silicon aluminum wire, platinum wire and other wires in atmospheric and vacuum environment is especially tested and analyzed. The burnout current of wires in atmospheric environment is significantly greater than that in vacuum environment. This result is consistent with the empirical formula substantially. The research is of referential value to the packaging of space infrared detectors.

Abstract:To realize the particularly high detection accuracy proposed by World Meteorological Organization (WMO) for atmospheric pressure profile and surface pressure, the interference of turbulence with range-resolved differential absorption lidars and integrated path differential absorption lidars should be removed. A detection beam and a reference beam are converted into a left-handed rotation polarization light beam and a right-handed rotation polarization light beam respectively. Then, both beams are emitted synchronously. The echoes transmitted by atmosphere are separated again by a 1/4 wave plate, a polarized light splitter and two F-P etalons and then are detected. To reduce the error due to the difference between two channels, the division, logarithm and integral operation are processed symmetrically by an analog circuit in real time. The same path transmission, synchronous emission and synchronous receiving of both the detection beam pulse of a differential absorption lidar and the reference beam pulse can cancel the common-mode interference of the factors such as atmospheric random motion with the system. The simulation research results show that the symmetric arrangement of a differential absorption lidar is a most beneficial measure for improving its detection accuracy.

Abstract:To verify the performance of a type II superlattice infrared detector, a driving circuit is designed for the detector. Because the infrared detector has high sensitivity, a low noise power supply bias circuit which can optimize the layout of the circuit board is designed. The driving circuit designed according to the characteristics of a 320×256 long wave infrared focal plane array is used to provide power and bias voltages and timing and control signals for the detector assembly. The experimental results show that this driving circuit can meet the lower noise and high precision requirements of the type II superlattice infrared imaging system.

Abstract:To meet the special application demands of civil aviation meteorologists who need to send aeronautical meteorological information periodically at all-weather time, a comprehensive monitoring and alarming system which has the functions of human body state detection, meteorological information release status monitoring and sound-light and voice alarming is developed. The system is based on infrared detection technology, microcontroller technology and computer programming technology. It can judge information sending state by detecting the working status of related personnel and decoding the contents of aeronautical information. Because the system can automatically call its backstage alarming molecule to alarm, it is a comprehensive monitoring and alarming system which can monitor the whole information sending process.

Abstract:Rotary kilns are the core equipment for clinker calcination in industrial production. To prevent the accidents caused by local high temperature, they need to be monitored in production in real time. In modern industries, the surface temperature of rotary kilns is usually monitored by infrared temperature measurement methods in real time. But in the process of monitoring, the faults should be located in real time. Traditional real-time rotary kiln monitoring methods generally use twodimensional images to display the surface temperature of rotary kilns. The thermal images obtained by these methods are poor in intuition and stereoscopic sense. To solve the above problems, a new method which can reconstruct the surface temperature fields of a rotary kiln in three dimensions and display the temperature information on the whole surface of the rotary kiln in pseudo color is proposed. The experimental results show that the three-dimensional model of the temperature field of the rotary kiln generated is better than traditional thermal images and is easier to be identified by operators. This is beneficial to industrial production.

Abstract:When a ground-based opto-electronic system is used to observe the space targets in the visible light waveband in the daytime, its detection ability will drop sharply due to the factors such as atmospheric scattering. Compared with the visible light waveband, the infrared waveband has strong atmospheric penetration ability. Therefore, to observe space targets in the infrared waveband can solve the detection problem occurred in the daytime. The influence of different atmospheric composition on medium wave infrared transmission is calculated and analyzed by a MODTRAN software and a medium wave infrared imaging system is used in a ground-based telescope for observation. The experimental results show that the medium wave infrared detector can detect the stars of seventh magnitude in the daytime and the average signal-to-noise ratio is 6.236. This research is of a certain referential significance to the space detection by ground-based infrared telescopes in the daytime.