大型储油罐温度检测技术研究

Temperature Measurement Technology Research of Large Storage Tank

目前的储油罐油温测量多局限于电类传感器,具有极大的安全隐患。基于安全考虑,提出了采用基于拉曼散射的全分布式光纤传感的方法,通过对油罐内传感光纤产生的背向拉曼散射光信号的测量与分析,得到油罐不同深度温度信息。针对噪声信号,提出了采用8 000次线性累加平均与小波模极大值配合使用的去噪方法。在系统标定时,利用MATLAB对光强比与温度数据进行三次多项式曲线拟合。对于2种光不等衰减问题,提出采用以e为底指数修正方法。最后对系统进行了精度分析,该系统可以实现油罐不同深度温度安全检测,在1.2 km范围内测温精度为0.8℃。

The large storage tank oil temperature measurements are confined to the electrical sensors, having great potential safety hazards. Based on safety, this paper puts forward fully distributed optical fiber sensing method based on Raman scattering. By measuring and analyzing the back Raman scattered light signals, tank temperature information can be obtained. For noise sig- nal, combination of 8000 times cumulative average and wavelet modulus maxima de-nosing method was proposed. When system calibration, MATLAB was used to fit experiment light intensity ratio and temperature data based on three times polynomial curve fitting. For both light unequal attenuation issues, a correction method based on the e exponent was proposed. Finally, the system can achieve large oil tank temperature of different depth, within 1.2 km, temperature measurement accuracy is 0.8℃.