A tunnel fire detection system and its fiber grating detector

Abstract

The invention discloses a tunnel fire detection system and its optical fiber grating detector. The optical fiber grating detector includes a temperature sensing element and a humidity sensor, which is used to detect the ambient humidity of the environment where the temperature sensing element is located. The output represents The humidity detection signal of the ambient humidity; the wiper is used to scrape off the water droplets on the temperature sensing element; the processor is connected with the humidity sensor and the wiper signal, and is used to receive the humidity detection signal of the humidity sensor, and the humidity The ambient humidity represented by the detection signal is compared with the preset humidity limit value. If the ambient humidity is greater than the humidity limit value, then under the ambient humidity, according to the relationship between the preset ambient humidity and the wiper start frequency, the corresponding ambient humidity will be used. Start the wipers at the start frequency. The ambient temperature is detected by the humidity sensor, and the starting frequency of the wiper is controlled according to the ambient humidity, so that when there is water on the temperature sensing element, the water is scraped off in time, so as to reduce the temperature detection lag of the temperature sensing element caused by the water on the temperature sensing element Influence.

Description

technical field [0001] The invention relates to a fire detection system, in particular to a tunnel fire detection system and a fiber grating detector thereof. Background technique [0002] In recent years, with the increasing investment of the Chinese government in infrastructure, traffic tunnels have ushered in a stage of rapid development. However, at the same time, the frequency of tunnel fires is gradually increasing, which seriously threatens the safety of people's lives and properties. Due to the closed environment of the traffic tunnel, it is not conducive to the heat diffusion of smoke and dust when a fire occurs, which makes it difficult to evacuate people, difficult to fight fires, and serious fire damage. Therefore, how to effectively prevent traffic tunnel fires and ensure the fire safety of traffic tunnels has become a topic of concern in the fire protection circles at home and abroad. [0003] In the prior art, the Chinese patent with the authorized announcem...

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Problems solved by technology

[0006] The above-mentioned fiber optic sensing tunnel fire alarm systems all use the temperature sensing element of the fiber optic grating temperature sensor for temperature detection. Due to the high ambient humidity in the tunnel, especially in rainy days, water droplets may accumulate on the temperature sensing element. If water droplets accumulate on the temperature sensing element, when the ambient temperature detected by it rises rapidly, due to the large specific heat capacity of water, more heat needs to be absorbed to raise the temperature to the ambient temperature, so the temperature detected by the temperature sensing element will lag behind. The ambient temperature in the tunnel, in the event of a fire, will prolong the response time of the fire alarm

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