Aspiration type laser image smoke sensing fire hazard detecting method and device

Abstract

A air suction type laser image method for detecting fire accient by sensing smoke includes such stesp as pumping smoke or aerosol in smoke detecting chamber, taking the scatter image of smoke particles under the action of laser by CCD camera, A / D convertion, analyzing by image signal processor to obtain relative parameters, classifying and judging by neuro network, and driving the alarm device if it is the smoke of fire accident. Its advantages are high sensitivity, high speed, and reliability.

Description

Technical field: [0001] The invention belongs to the technical field of fire detection, and in particular relates to a method and a device for detecting a smoke-sensing fire with a laser image. Background technique: [0002] Smoke is one of the early characteristics of fire, and smoke detection is an important field of fire detection. The point-type smoke detector has the characteristics of simple structure, low cost, large application, and wide distribution. It is one of the main detection devices in the current automatic fire alarm system. The point-type smoke detector includes photoelectric smoke detection There are two types of detectors and ionization smoke detectors, and photoelectric smoke detectors include two types of scattered light and dimming. According to the "Applied Laser" 2001 No. 2 (Vol.21, No.2, pp.79-81) sponsored by the Chinese Optical Society, point-type smoke detectors are limited by their detection mechanism and structural design. However, there are ...

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Problems solved by technology

[0003] ① Ionization smoke detectors are not strong in anti-airflow interference, and are easily affected by changes in ambient temperature, humidity and air pressure. At the same time, because radioactive substances are used in the ionization chamber, they will have adverse effects on the environment and human body, and their application is subject to certain restrictions. limit;

[0004] ② Photoelectric smoke detectors are sensitive to large particles of smoke particles produced by smoldering combustion, while ion smoke detectors are sensitive to small particles of smoke particles produced by open flames; when the detector is set at a certain sensitivity level, the small particles The alarm can only be alarmed when the smoke reaches a higher concentration, which will easily lead to false alarms; if the sensitivity is adjusted to a higher level, the probability of false alarms will increase;

[0005] ③The color of smoke is different from bright (gray) and dark (black). The scattered light photoelectric smoke detector is sensitive to gray smoke, but not to black smoke; the dimming photoelectric smoke detector is more sensitive to black smoke. Good response, but not sensitive to off-white smoke; coupled with differences in the composition and particle size of fire smoke, the sensitivity of existing point-type smoke detection technology to open flames and smoldering smoke of different combustion objects or the same combustion object Inconsistent;

[0006] ④In practical applications, point-type smoke detectors are susceptible to interference from non-fire factors such as dust and electromagnetics, and are prone to false alarms

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