It is an important prerequisite for high performance of the whole dredger to maintain safe and effective operation of the conveying system during dredging process. Due to the complex operation processes, current monitoring and adjustment operations of the conveying system are mostly based on personal operation experience. There is a lack of monitoring, evaluation and accurate control methods for the overall working status of the conveying system. This paper intends to research and establish a monitoring and optimization scheme which can monitor and deduce the working status of the entire pipeline in real time, applying relevant theories and analysis methods of sediment movement mechanics, after conducting a field test and analysis of a reclamation project in China. In order to solve the problem of monitoring and predicting the risk of pipe blockage in the dynamic operation of the transportation system, the method of lower limit velocity parameters of key monitoring points is adopted; while the parameters of lower limit velocity at key monitoring points and economic velocity range (which is defined by the critical velocity) of the entire pipeline are taken as the major control factors, according to the working characteristics of the conveying system; On this basis, a dynamic monitoring and optimization scheme of conveying system is put forward according to its operating properties. The comparative analysis and calculation are carried out based on the measured data from the field test.The results show that the monitoring and optimization scheme proposed in this paper can accurately deduce the entire pipeline conveying parameters in real time; and the operation parameter of the conveying system can be real-time optimized and adjusted on the premise of ensuring safety, to maintain the relatively efficient and stable operation status.
Hydraulic Dredger, represented by Trailing Suction Hopper Dredger (TSHD) and Cutter Suction Dredger (CSD), is the most popular ship type in dredging industry, which is widely used in inland and offshore dredging and reclamation projects. Conveying system, composed of slurry pump(s), pipeline, supporting and auxiliary devices, is one of the key and main energy consumption components of hydraulic dredger, performing the function of suction and discharge of dredged material. Its working performance is the key factor for construction efficiency and energy consumption of hydraulic dredgers (Xiong et al., 2015; Li et al., 2017). Generally, designed slurry pump power can account for 20-40%, 40-60% of the total installed power of large and super larger TSHD for trailing (dredging) operation and discharging operation respectively (Zhang, 2003). The operation mode for conveying system of CSD may be adopted due to the change of conveying distance, and the energy consumption of conveying system may account for more than 80% of the total (Bi et al., 2009; Li et al., 2017). Therefore, it is an important premise for high-efficiency and energy-saving operation of the whole dredger, to keep the conveying system working safely and efficiently through reasonable optimization and adjustment measures, on the basis of real-time monitoring of relevant operation parameters.
