Study On Hydraulic Characteristic And Optimum Design Of Pump System With Slanting And Extensive Shaft

According to the angle between pump shaft and horizontal line, a pump system could be divided into three types, which are vertical pump system, slanting pump system and horizontal pump system, respectively. A pump system with slanting and extensive shaft is one of the low head pump systems, and has many advantages, such as more simple pump house structure, less hydraulic loss, higher pump system efficiency, more convenient installation and management, better condition of heat dissipation, etc, which means the pump system has the higher application value and potential.The construction of large pumping station engineering in our country gives an impulse to research on the both vertical pump system and bulb tubular pump system with horizontal shaft. Because the reliability of the pump bearing, the pump system with slanting and extensive shaft has been disbelieved for a long time, it is applied scarcely and its hydraulic performance is not studied in more depth. With the rapid development of the whole industry level of our country, the problem of the bearing has been basically solved, and the application prospect has been unfolded. Therefore the optimum hydraulic computation for the hydraulic performance of the inlet and outlet conduit of the pump system is studied deeply. And the hydraulic performance is compared and analyzed among the pump systems with different pump shaft angle for the first time in this paper, so as to further enrich the types of the low head pump system for application.With the help of the FLUENT software, the numerical computation of 3-D turbulent flow of the ZBM791 prototype pump section is completed, based on which the flow performance of the pump is analyzed, and the computation result of the energy performance is compared with that of the model test. The comparison results indicate that the numerical computation method used in this paper is feasible, which provides a necessary technology condition for the numerical computation of 3-D turbulent flow in the pump system.With reference to the main data of a low head pumping station, the numerical computation of 3-D turbulent flow and the optimum hydraulic design for the inlet conduit of the pump system with 3 different pump shaft angles,which are 15°, 30°and 45°, respectively, is completed by application of FLUENT. The interior flow patterns and the hydraulic losses of the 3 inlet conduits are obtained, and the change trend of the hydraulic performance with the increase of the pump shaft angle is analyzed.Based on the data of the same pumping station, the numerical computations of 3-D turbulent flow and the optimum hydraulic designs for the slanting outlet conduit of the pump systems with different angles are also completed, respectively. The interior flow pattern and hydraulic loss of each outlet conduit are analyzed and their interior flow patterns and hydraulic losses are compared.With the help of CFD theory and technology, the numerical computations of 3-D turbulent flow for the pump system with different angles are completed, respectively. The flow patterns and hydraulic losses of the conduits are compared between the two conditions: one is the computations for the whole pump systems, and the other one is the computations for the conduits only.In order to verify the numerical computation results of the slanting inlet conduit, the model test research for the 3 slanting inlet conduits with different angles are completed, respectively. The interior flow patterns of each conduit are observed and the hydraulic losses are measured, and the model test results are compared with the numerical computation results. The comparison results indicate that test results are basically consistent with the numerical results, nevertheless, the numerical results are somewhat less than the test ones.The hydraulic performance of the pump system with slanting and extensive shaft is excellent, and it could be suitably applied by low head pumping station. The hydraulic performance of this type of pump system is needed to be researched more deeply in the future, so as to be applied to the engineering much better.