Analysis Of Flow Characteristics And Wear Performance And Research Of Impeller Structure To Reduce Wear Of Deep-sea Mining Pump

The mining pump is one of the core equipment in the deep sea mining conveying system,and it is the key equipment that determines the success of deep sea mining.Due to the influence of factors such as deep-sea environment and complex operating environment,deep-sea mining pumps are required to have the characteristics of high lift,good flow capacity,good wear resistance and stable hydraulic performance.According to the actual operating characteristics of the deep-sea mining pump,different particle parameters and operating conditions will affect the flow characteristics and hydraulic performance in the mining pump.The wear of the flow passage components is directly related to the wear of the mining pump,so it is of great significance to use the appropriate optimization method to optimize the structure of the mining pump.In this paper,theoretical analysis,numerical simulation,experimental research and optimization research methods are used to conduct in-depth research on the hydraulic performance,flow characteristics,wear performance,wear test and impeller structure wear reduction optimization of deep-sea mining pumps,and form a systematic research results.The main research contents are as follows:(1)Based on the deep-sea mining pump designed according to the overall requirements of the project,the hydraulic performance test was carried out under the condition of clear water,and the hydraulic performance change data was obtained.The test results show that the designed deep-sea mining pump meets the requirements,and the test The results are consistent with the change trend of the numerical simulation results,and the error between the performance data is within a reasonable range,which verifies the correctness of the numerical calculation method.Research on wear performance and wear reduction optimization of impeller structure provides important support.(2)Based on the SST k-ω model and the DPM model,different particle parameters(six particle sizes,three particle densities and three particle volume concentrations)and different operating conditions(three rotational speed conditions and three flow conditions)were studied.The flow characteristics of the flow passage components of the deep-sea mining pump and the influence on the hydraulic performance output are obtained.The influence results of these particle parameters and operating conditions on the flow characteristics of the deep-sea mining pump,as well as the influence results on the head and efficiency are obtained.The changes of the internal flow characteristics and hydraulic performance of the deep-sea mining pump when conveying solid-liquid two-phase flow are comprehensively revealed.(3)Based on the SST k-ω model and the DPM model,combined with the wear model selected for the deep-sea mining pump,the wear performance of the flow passage components of the deep-sea mining pump under different particle parameters and different operating conditions was studied,and the first-stage impeller,Surface wear distribution results and wear rate variation results of the primary guide vane,secondary impeller,and secondary guide vane.It provides a theoretical reference for the structural optimization of deep-sea mining pumps that transport different coarse-grained minerals.(4)A test pump with the same specific speed and similar structure as the deep-sea mining pump was developed,and the qualitative wear verification test of the mining pump was carried out for the first time.Three qualitative wear tests were carried out on the test pump under small flow conditions,rated flow conditions and large flow conditions.The experimental wear results and the numerical simulation wear results were compared and analyzed.The results show that the wear results of each flow passage components are consistent,indicating that the wear model used in this paper can more accurately predict the wear of the surface of the deep-sea mining pump flow passage components,and the model used in this paper is correct.This provides an important reference for the wear test research,development and application of deep-sea mining pumps.(5)Based on Response Surface Methodology(RSM),wear reduction optimization of impeller structure of deep-sea mining pump was studied.Plackett-burman design was performed using Minitab software to identify four factors that are most sensitive to the performance of deep-sea mining pumps.Expert Design software was used to conduct experimental Design for the four most significant control variables screened out according to box-Behnken Design(BBD)method,and 29 groups of models were established combining these factors.The optimal hydraulic model was found through multiple regression analysis,and the optimal model pump was taken as the object.Particles with different parameters under different flow conditions and head,efficiency,shaft power,and the change of the impeller wear and tear strength,the optimal model of the pump will be the results with the original mining pump is analyzed,the result shows that in ensuring that lift and efficiency under the condition of stable or close to,the simulation to get the optimal model of the pump impeller wear rate was reduced by 29.5% on average.This provides an important reference for the optimization of structural wear reduction and wear performance of deep-sea mining pump.