The national standard flame detector stipulates that the response time of point-type ultraviolet flame detectors is acceptable within 30s, but due to the advancement of technology, the response time of flame detection alarm products on the market can meet this time range, but this is necessary for practical applications and security requirements, and the requirements for indicators and performance are getting higher and higher. The response time of most domestic police systems is seconds, and the response speed of Japan and the United States can reach ms. The detection distance of foreign flame detectors that can be consulted is 500 meters, which cannot be used for flame detection at longer distances. The flame detectors on the market mainly include smoke sensors, infrared sensors and ultraviolet photosensitive tubes. Even for flame detection systems that use multi-information fusion technology, the information sources of their detection are mainly these three aspects. Traditional flame detection sensors have the following shortcomings:
Flame detectors
1. Smoke sensor, which is an indirect flame detector. When the flame is generated, smoke is also generated. When the smoke reaches a certain concentration, an alarm signal is issued. There are great disadvantages in detecting flames in this way. Some substances do not produce smoke when they burn (such as natural gas, ethanol, methanol, etc.), and the detection distance is short. The sensor must be in a location with dense smoke. It can be seen that when the flame occurs and the smoke is dense, then the alarm may be too late in some occasions.
2. The thermal release infrared flame detector in the flame detector directly detects the infrared spectrum with a wavelength of 4.35±0.15μπ in the flame. The detection target is relatively clear. It consists of a thermal release probe and an amplifier. The disadvantage is that this type of sensor is piezoelectric and is very sensitive to sound electromagnetic waves and vibrations, so the place of use is subject to certain restrictions, and its detection distance is less than 80m.
3. Conventional ultraviolet flame detectors directly detect the ultraviolet spectrum of 180-260nm in the flame. The detection target is also very clear and the response speed is relatively fast. It consists of an ultraviolet sensitive probe and an amplifier. The disadvantage is that the sensitivity is poor, the detection distance is less than 15 meters, it cannot resist the interference of lightning, and there is a certain false alarm rate. Therefore, it is only used in short-distance closed environments, such as furnaces, industrial boilers, etc.
In view of the characteristics and limitations of different types of flame detectors, how to integrate the real-time and accuracy required for fire detection alarms, the high-speed response of flame detection, long-distance detection (for different places), and accurate reporting have become difficult problems that flame detection technology must solve.
The national standard flame detector stipulates that the response time of point-type ultraviolet flame detectors is acceptable within 30s, but due to the advancement of technology, the response time of flame detection alarm products on the market can meet this time range, but this is necessary for practical applications and security requirements, and the requirements for indicators and performance are getting higher and higher. The response time of most domestic police systems is seconds, and the response speed of Japan and the United States can reach ms. The detection distance of foreign flame detectors that can be consulted is 500 meters, which cannot be used for flame detection at longer distances. The flame detectors on the market mainly include smoke sensors, infrared sensors and ultraviolet photosensitive tubes. Even for flame detection systems that use multi-information fusion technology, the information sources of their detection are mainly these three aspects. Traditional flame detection sensors have the following shortcomings:
Flame detectors
1. Smoke sensor, which is an indirect flame detector. When the flame is generated, smoke is also generated. When the smoke reaches a certain concentration, an alarm signal is issued. There are great disadvantages in detecting flames in this way. Some substances do not produce smoke when they burn (such as natural gas, ethanol, methanol, etc.), and the detection distance is short. The sensor must be in a location with dense smoke. It can be seen that when the flame occurs and the smoke is dense, then the alarm may be too late in some occasions.
2. The thermal release infrared flame detector in the flame detector directly detects the infrared spectrum with a wavelength of 4.35±0.15μπ in the flame. The detection target is relatively clear. It consists of a thermal release probe and an amplifier. The disadvantage is that this type of sensor is piezoelectric and is very sensitive to sound electromagnetic waves and vibrations, so the place of use is subject to certain restrictions, and its detection distance is less than 80m.
3. Conventional ultraviolet flame detectors directly detect the ultraviolet spectrum of 180-260nm in the flame. The detection target is also very clear and the response speed is relatively fast. It consists of an ultraviolet sensitive probe and an amplifier. The disadvantage is that the sensitivity is poor, the detection distance is less than 15 meters, it cannot resist the interference of lightning, and there is a certain false alarm rate. Therefore, it is only used in short-distance closed environments, such as furnaces, industrial boilers, etc.
In view of the characteristics and limitations of different types of flame detectors, how to integrate the real-time and accuracy required for fire detection alarms, the high-speed response of flame detection, long-distance detection (for different places), and accurate reporting have become difficult problems that flame detection technology must solve.