Research And Implementation Of Infrared Flame Detector

In recent years,the state has paid more and more attention to fire protection,and the tunnel fire prevention is a very important part of the fire control link.Due to the relatively closed space is narrow and the road tunnel traffic is relatively large,the evacuation and rescue are more difficult,these places once the fire is no timely alarm and take measures,it is easy to cause a large number of vehicles into the tunnel,fire fighting and evacuation of personnel will be very difficult,and the rescue difficult,often caused by extremely destructive and dangerous consequences.The flame detector with high reliability is helpful to discover fire at the first time,fire alarm in time,organize rescue quickly,and reduce personnel injury and economic loss to the utmost.Aiming at tunnel fire,a new type of point infrared flame detector is researched and developed in this paper.The problems of long time,low sensitivity and low detection reliability of the existing flame detectors are solved.Firstly,the development of flame detectors at home and abroad is investigated,and the useful information in flame combustion is analyzed.The real flame signals are selected according to the flame flicker frequency.The principle of point infrared flame detector is also discussed,and the working principle of the key device(pyroelectric sensor)is analyzed,and the theoretical knowledge is saved.According to the theoretical knowledge,the hardware circuit is designed.The hardware circuit includes signal acquisition board,signal processing board and signal power board.The three wavelength intelligent flame detection algorithm with high sensitivity design algorithm based on the center wavelength of three sensors and pass band width can be obtained.The ratio of relations into three different sensor flame radiation power and radiation interference power,according to the FFT(fast Fourier transform)to obtain the real flame and the interference peak radiation spectrum.The algorithm is simulated by several real ignition experiments in labview.The results show that the automobile headlamps,sunlight,artificial heat sources and other interference have strong resistance,and the detection distance and angle can reach the leading level in china.Finally,the prototype verifies its reliability and strong anti-interference ability in the field ignition environment,and through the performance test of the national standard,electromagnetic interference experiment,temperature box experiment,pulse groupexperiment,mechanical vibration experiment.The test results show that the flame detector in this paper can be used in practical engineering,and the finished sample machine has the advantages of long detection distance,fast response block and strong anti-interference ability,so as to meet the design requirements.