Research On Detecting And Control Key Technologies In Long-distance Slurry Pipeline Transportation

Long-distance slurry pipeline transportation has many advantages over other transportation technologies, such as larger capacity, less land use, less reliance on climate conditions, more energy saving and reduced emission. With the increase in demand for mineral resource in suburban areas, the need for long-distance slurry pipeline also rises significantly. However, during the slurry pipeline transportation process, sedimentation, blockage and severe wear may easily occur. Accurately detecting and controlling the velocity of the slurry flow is key to solving these problems. At present, most of the established slurry pipeline transportation systems in our country are provided by foreign companies. However, the current technology cannot ensure accurate detection of the slurry flow velocity under all circumstances. In addition, automation control under various complicated conditions needs to be improved. This study is part of the National Science and Technology Support Program Project, titled "Research on the key technologies of the secure operation of slurry pipeline in complex terrains". It focuses on the detection and control issues pertaining to the long-distance slurry pipeline transportation process and aims to provide solutions for the accurate intelligence detection and control of the transportation system under complex conditions. The main findings are summarized below.1. This thesis analyzes the process flows and parameters of the long-distance slurry pipeline, studies the characteristics of slurry pipeline transportation.The key points in the slurry pipeline transportation process control are analyzed, Pipeline transportation process hybrid control system framework is proposed. Through the modeling of each section of pipeline flow control and the dynamic model of pipeline, a continuous way of conveying velocity control of the process model is put forward and set up.The transportation velocity control system of the slurry pipeline is proved to be a transfer delay system with characteristics such as nonlinearity, time varying, multi-input multi-output and strong coupling.2. Through reviewing theories and conducting experiments, the disturbance of using the electromagnetic flow meter to measure flow velocity of the slurry pipeline transportation is analyzed. A detection system of slurry flow velocity based on multi-sensor information integration is developed. The characteristic parameters related to the slurry flow velocity are determined and extracted, such as pressure difference fluctuation factor, flow fluctuation factor and etc. The correlations between these parameters and the slurry flow velocity are analyzed. Based on the features extracted from multiple sensors, AdaBoost is combined with FCMAC to identify the facticity of flow velocity data. An improved AdaBoost-FCMAC recognition algorithm as false data identifier is proposed. The experiment results confirm that this method can achieve accurate and real-time detection of slurry flow velocity under complex operating mode.3. The operating modes of the actual process of the industrial multi-pump station pipeline transportation change very frequently. Hence, human-simulated multi-mode controller structure and algorithm based on the complex inverse control with Application to the flow velocity control for Slurry Pipeline are proposed. The deduction process from feature recognition to total output of human-simulated multi-mode control is presented. The reversibility of the pipeline flow adjustment system is analyzed, and the inverse control model based on wavelet neural network is constructed. The flow velocity complex NPID inverse control is proposed. The results of experiments and simulation have confirmed the high performance of this algorithm, and the validity of the control structure and algorithm.4. The restart technology after slurry pipeline transportation system failure is investigated. In order to ensure the slurry pipeline transportation system can safety re-start from the special working conditions, the start characteristics of transmission system parts and control laws are analyzed. Switching control based on intelligent recognition is designed to meet the requirements of slurry restarting. Through the intelligent recognition and diagnosis of system status, restarting with gain-varying and step-varying by means of switching control is realized by using the combination of expecting standard value and adjustment value. The experiment results show that the automatic restarting of slurry by means of switching control based on intelligent recognition is safe and stable even after a long-term pump-stop.5. On a simulated experimental base of long-distance slurry pipeline transportation in our country, the whole operating mode intelligent measurement and control system of industry standard based on complex step idea is developed. The practical application of the measurement and control system based on multi-sensor fusion and intelligent control method is achieved. The transportation characteristics and parameters of slurry pipeline are studied, and the simulation of automatic multi-pump slurry pipeline transportation control on different industrialization conditions is achieved. The robustness and stability of the proposed method are then verified.The proposed intelligent measurement and control technique in this thesis can resolve the difficulty of accurately detecting the flow velocity of slurry transportation, and achieve stable control under strong disturbance and special operating modes. The findings of this research are innovative and have engineering practical value. There are also good prospects in their extended applications.Finally, the main innovative research results are summarized, and further study directions are discussed.