Abstract：Rapid identification of coal mine inrush water source is of great significance to coal mine safety production, therefore，laser induced fluorescence technology is used in the rapid identification of coal mine inrush water, which broke the insufficiency of a long time spent on traditional chemistry method. Mine goaf water is the most common and the most harmful type of water source, and the temperature is one of the most important factors that affect the physical properties. Studying the temperature characteristics of laser induced fluorescence detection of the goaf water can help to quickly and accurately identify mine inrush sources, which has important academic significance and practical value. In this paper, 405 nm blue-violet semiconductor laser as a light source, the laser power is set to 120 mW, the generating laser light is supposed to go by the UV/Vis quartz fiber and expose the water sample by fluorescence probe before the tested water samples are activated by laser to generate the fluorescence which is collected by a fluorescence probe. Finally it is transmitted to the spectrometer through quartz fiber.Taking the goaf water collected from Zhangji Coal Mine in Huainan in March 2017 as the research object, the suspended particles in the water sample is filtered out before placing it in the beaker and reducing the sample temperature to 5 ℃ with ice cubes to. Then it is put into a constant temperature bath pot, using the iron stand fixed fluorescent probe to deposite it at a place 1 cm under the liquid surface. In the process of fluorescence spectrum acquisition, the sample is always placed in a constant temperature water bath, and the fluorescence spectra were obtained by controlling the temperature of the sample in the water bath over the temperature range of 10.0～60.0 ℃, and discusses the effects of temperature variation on the laser induced fluorescence spectra, peak position, peaks, temperature coefficients and spectral area of the goaf water. The results show that, with the increase of temperature, the molecular motion is accelerated, the probability of collision between the molecules is increased. As a result, the non-radiative transition increases, the fluorescence efficiency of the goaf water decreases, the fluorescence intensity is weakened, and the overall attenuation of the fluorescence spectra is mainly concentrated in the 400～700 nm band. The wavelength of the two peaks in the fluorescent spectra of the goaf water remains unchanged, which did not drift with temperature. The fluorescence intensity of two peaks (472 and 493 nm) is where it is weakened the most. Besides, there is a good linear relationship between the decrease of fluorescence intensity and the temperature rise, the correlation coefficient r2 is 0.91 at 472 nm, and the fitting correlation coefficient r2 is 0.963 36 at 293 nm. The temperature coefficient at 472 nm reached a minimum of 0.34% at 20.0 ℃, 493 nm temperature coefficient at 20 ℃ when the minimum value of 0.81%, both temperature coefficients in 20 ℃ to achieve the lowest value that fluorescence spectra in the vicinity of 20 ℃ the most stable. When the temperature increases, the area of the old air water in the 400～700 nm band and the temperature axis is gradually reduced, the correlation coefficient r2 of the area and the temperature of the 400～700 nm band spectrum is 0.975 39, i.e. the decrease of the area and the temperature rise has a good linear relation. By studying the temperature characteristics of the mine goaf water, the laser induced fluorescence spectrum of the mine goaf water is the most stable at 20 ℃, and under this temperature condition, the laser induced fluorescence technique is the most effective to identify the mine water source. At the same time, the temperature compensation by using the linear relation of the goaf wave peak and the area to the temperature can further enhance the sensitivity and accuracy of the identification of mine water inrush by using LIF technology. The study is of great significance to realize fast and accurate discrimination of mine goaf water.
