Research On Hydraulic Design Standardization Of Shaft Type Inlet Passage

The front vertical cross-flow pump is one of the commonly used types of low-lift pumping stations.It has the characteristics of excellent hydraulic performance,good heat dissipation of the motor and convenient installation.More and more low-lift pumping stations use this form With the acceleration of China's urbanization process and the improvement of flood control standards,it is expected that a large number of low-lift pumping stations will be built.The shaft inlet flow passage is an important part of the pre-shaft cross-flow pump device,which can provide good water inlet conditions for the pump and has a significant impact on the overall efficiency of the pump unit.Therefore,the research on the shaft flow passage has practical significance and practical valueAfter analyzing the application and research status of the shaft type inlet passage,it is found that there are two main problems in the flow channel design process:1.There are a lot of repeated design work;2.The overall efficiency of the pump unit is not uniform.In order to solve these two problems,this paper proposes a hydraulic design standardization study on the front vertical shaft inlet passage.The significance of this research is to ensure the high quality of the hydraulic performance of the design flow channel,ensure the stable operation of the entire pump device,avoid the repetitive design work,and facilitate the further application of the results.The research contents of this paper are as follows:(1)Analyze the existing data,obtain the favorable conditions for implementing the hydraulic design standardization of the front vertical shaft inlet flow passage,and determine the specific requirements that correspond to the standardized results.The favorable conditions are reflected in the development of the hydraulic design method,the main installation dimensions of the common water pump model and the difference between the control values of the flow channel.The requirements are reflected in four aspects:excellent hydraulic performance,reasonable series division,wide application range and convenient application.(2)Introduced the concept of the nominal average flow rate of the pump,and determined the parameters that control the size of the passage in the shaft type inlet passage.By the basis of statistical analysis,determine the value of each control parameter according to the needs of the project.Finally,according to the importance of the control parameters,the nominal average flow velocity of the pump and the maximum width of the outer wall of the shaft.Determined the key parameters in the standardization of hydraulic design and divide into 24 standardized schemes.(3)According to the control flow rate requirements and other restrictions,determine the specific parameters of each scheme in the hydraulic design standardization study of the shaft type inlet flow passage,And after the hydraulic optimization design,24 shaft type inlet flow passage standardization optimization schemes are formed.Through the verification of numerical calculation,there is no bad flow state in the flow channel,and the hydraulic performance is excellent.The flow rate distribution uniformity is between 98.3%and 98.5%,and the water inflow pump angle is between 88.80 and 89.2°.(4)In order to expand the application range of the hydraulic design standardization research results of the front shaft type inlet water passage,two adjustment methods are determined by the specificity of the standardization scheme.(5)In order to facilitate the selection and application of the hydraulic design standardization research results of the shaft type inlet water passage,the corresponding software was compiled by Visual Basic languageIn this paper,the hydraulic design standardization research of the shaft inlet flow passage is carried out,24 kinds of standardized shaft type inlet water passage schemes which can meet the actual needs of the project are proposed,and the corresponding selection procedure is designed,which can effectively improve the front position.The design level of the shaft-type inlet passage avoids repeated hydraulic design work.And it laid the foundation for the implementation of the standardization of the shaft inlet flow passage.