Research On Leakage Monitoring Method And System Of Buried Oil Tank

Buried oil tanks are the main way of oil storage in gas stations.At present,there are about119,000 gas stations in China and nearly 476,000 buried oil tanks.Due to the long-term influence of mechanical stress and corrosion,most of the oil tanks are in danger of leaking at any time.Oil tank leakage not only causes economic losses,but also pollutes soil and groundwater,posing a threat to the surrounding environment and population.Although domestic and foreign research and development of related leakage monitoring technology products,it is still difficult to detect microleakage,and it is even more difficult to achieve leakage positioning.This article adheres to the principle of early detection and early elimination of potential safety hazards.On the basis of existing research,a two-layer oil tank leakage detection scheme based on array electrodes and distributed liquid levels is proposed,and a cross-plane array sensor for leakage detection of buried horizontal oil tanks is designed,developed a set of monitoring system for micro-leakage of buried oil tanks,carried out correlative verification experiments with different leakage rates and leakage locations,and adopted a neural network-based data fusion method.The training and learning of the data set verifies the feasibility of the leakage monitoring program in this paper.The main research work and innovations of this paper are as follows:(1)The mathematical model of the cross-plane array sensor was established,and the structural parameters were optimized by using finite element simulation to analyze the response characteristics of the array electrode under different working conditions through the capacitance variation range,sensitivity,and non-uniformity of the sensor performance indicators.The optimized parameters are as follows: Electrode spacing L=2.2mm,electrode thickness d =0.4mm of 2*4 array electrode.Test experiments on different substances,electrode layers,and different electrode response characteristics verify the effectiveness and reliability of the array electrode leakage monitoring.(2)A set of leakage monitoring system is developed through the modular design of software and hardware.The analog circuit is composed of a micro capacitance detection circuit,a liquid level processing circuit,an electrode switching circuit and a power supply circuit,and the digital circuit is composed of a data acquisition circuit with FPGA+AD7606 as the core.Through testing experiment,each circuit module has good working performance,among which the switching control logic realizes the sequential excitation,detection and ground gating of the array electrodes,and the dual-channel acquisition control program realizes the data acquisition of the array electrodes and the distributed liquid level.(3)According to the two types of sensor data collected by the leakage monitoring system,data fusion is carried out through the neural network,and the LMSE function is continuously corrected under the condition of the steepest descent method to approximate the expected value theory,and the array electrode and the liquid level data set are trained and learned,The accuracy rate of leakage location identification is as high as 98.62%,which can realize the accurate positioning of buried oil tank leakage monitoring.(4)Combining the optimized structure parameters of the array electrode and the distributed liquid level sensor to construct an indoor micro-leakage monitoring simulation test system,and carry out simulation experiments on different leakage conditions.The experimental data show that the proposed optimized parameter array electrode is effective detect micro-leakage.Both the leakage volume and the leakage location are sensitive to the response,and the distributed liquid level detection has high stability and fast response.Experimental test results: within the range of0.41% to 2.1% leakage rate,the average relative error of leakage rate measurement is 3.18%,and accurate positioning of the leakage area can be achieved.Through the above-mentioned proposed buried oil tank leakage monitoring plan,array electrode sensor parameter optimization,leakage monitoring system research and indoor experimental work,the theoretical basis and practical basis for the micro leakage monitoring of buried oil tanks are provided.