Research And Development Of Triple Channels Infrared Flame Detector

Advanced fire detection technologies have great significance in ensuring safty production in petrochemical industrial field. Domestic existing fire detectors have the disadvantages of long response time, low sensitivity and low reliablity, and are difficult to meet the strict requirments in the sophisticated industrial field. This dissertation has researched and developed a new triple channels infrared flame detector, putting an emphasis to solve the above problems:First, the design of triple channels infrared detector is proposed. Flame signal, man-made heat sources and background radiant interference channels are established based on the profound researches of spectrums of flame, man-made heat sources and background radiant interference. Detection response time is shorten through detecting the characteristics of infrared radiation of combustion in early age. Interference immunity is improved by detecting and analyzing the characteristics of interferences. Detection reliability is improved through filterating interferences according to flame flickering frequency.Second, hyper-sensitive triple channels flame recognition algorithm is proposed. The logic relationship of triple channels signal amplitude is comparatively stable while the amplitude decays sharply as the transmission distance increases. Infrared radiation type is recognized to differentiate the flame and interferences through analyzing the logic relationship of triple channels signal amplitude, improving the effective detection distance and flame detection sensitivity.Finally, with the DSP as the core, the hardware and software design of triple channels infrared flame detector is proposed. Due to the lack of time, only the prototype machine is developed, and the detection distance, interferences immunity are tested on the machine. Tests results prove the excellent performances of the machine, though, there is still certain gap between the machine and international advanced detectors. By using better infrared sensors, applying better curcuits and infrared optical lens to the detector, better performances can be achieved.