煤矿井下突水水源的快速判别对煤矿安全生产意义非常重大, 激光荧光技术用于煤矿突水水源的识别打破了传统水化学方法耗时长的不足。 矿井老空水是最常见也是危害最大的水源类型, 而温度是影响物质特性的重要因素之一, 研究激光诱导荧光检测老空水的温度特性有助于快速准确识别矿井突水水源, 该研究具有重要的学术意义和实用价值。 采用405 nm蓝紫光半导体激光器作为光源, 设定激光器功率为120 mW, 产生的激光经UV/Vis石英光纤由荧光探头照射待测水样, 待测水样受激光激发产生荧光由荧光探头采集, 通过石英光纤传输至光谱仪。 以2017年3月在淮南市张集煤矿采集的老空水作为研究对象, 首先过滤掉水样中的悬浮颗粒, 随后将其放置在烧杯中, 使用冰块使样品温度降低至5.0 ℃, 随后放入恒温水浴锅中, 使用铁架台固定荧光探头使其位于液面下1 cm处。 在荧光光谱采集过程中, 样品始终放置在恒温水浴锅中, 通过水浴锅控制样品在10.0~60.0 ℃温度范围内获取荧光光谱, 并讨论了温度变化对老空水激光诱导荧光光谱谱图、 波峰位置及峰值、 温度系数、 谱图面积的影响。 研究结果表明: 随着温度升高, 加速了分子运动, 增加了分子间碰撞的概率, 使得非辐射跃迁增加, 老空水的荧光效率下降, 荧光强度减弱, 荧光光谱整体呈衰减变化主要集中在400~700 nm波段; 老空水荧光光谱的两个波峰所对应的波长保持不变, 并未随着温度变化发生漂移, 两个波峰处(472和493 nm)荧光强度减弱最明显, 同时荧光强度减弱与温度升高存在较好的线性关系, 荧光强度和温度在472 nm处拟合相关系数 r²为0.91, 在493 nm处的拟合相关系数 r²为0.963 36; 472 nm处的温度系数在20.0 ℃时达到最小值0.34%, 493 nm处的温度系数在20 ℃时达到最小值0.81%, 两处的温度系数均在20.0 ℃时达到最低值即荧光光谱在20.0 ℃附近最稳定; 温度升高, 老空水在荧光光谱在400~700 nm波段与温度轴包围的面积逐渐减小, 400~700 nm波段谱图所对应的面积与温度的拟合相关系数 r²为0.975 39即面积的减小与温度的升高有良好的线性关系。 通过研究矿井老空水的温度特性, 矿井老空水的激光诱导荧光光谱在20 ℃最稳定, 在该温度条件下采用激光诱导荧光技术进行矿井水源的识别效果最佳, 同时利用老空水波峰以及面积与温度的线性关系进行温度补偿可以进一步提升利用LIF技术进行矿井突水水源识别的灵敏度和精度, 该研究对实现矿井老空水的快速、 准确判别具有重要意义。

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.