Research on inflow and energy conversion characteristics of centrifugal pump as turbine in different conditions
LIN Tong1,2*, XIE Jing1,XIE Renhua1
1. College of Mechanical and Electronic Engineering, Jiangxi College of Applied Technology, Ganzhou, Jiangxi 341000, China; 2. National-Provincial Joint Engineering Laboratory of Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
Abstract：To reveal the energy conversion characteristic of the pump as turbine(PAT)under different discharges, a single-stage cantilever centrifugal pump with the specific speed of 90 under the turbine mode was studied. By applying the finite volume method(FVM)to simulate the performance of diffe-rent flow rates, the accuracy of numerical simulation was validated by experimental results. The results show that the impeller is the main component of hydraulic loss in PAT. With the discharge increasing, the proportion of hydraulic loss in the impeller shows the tendency of decreasing first and then increa-sing. Under the design operating condition(Q=80 m3/h), the proportion of hydraulic loss of volute, impeller and cavity is 33%, 35.1% and 22.3%, respectively. By analyzing the distributions of stream-lines and velocity triangle at the inlet of the blade under different conditions, the relation between the flow characteristic and the hydraulic loss was revealed. The flow in the impeller is uniform and without vortex. However, the poor flow characteristic can be observed with the discharge deviating from the design condition. The backflow occurs at the inlet of the impeller under the part-flow condition, and the vortex occurs at the suction side of the blade under the large-flow condition. Finally, to further research the mechanism of energy conversion, enstrophy coefficient was utilized to analyze the hydraulic loss from the aspect of energy. The research results could provide references for the efficient design and operating of PAT.
林通*,谢京,谢仁华. 离心泵作透平多工况内流与能量转换特性[J]. 排灌机械工程学报, 2021, 39(10): 994-1000.
LIN Tong*,XIE Jing,XIE Renhua. Research on inflow and energy conversion characteristics of centrifugal pump as turbine in different conditions. Journal of Drainage and Irrigation Machinery Engin, 2021, 39(10): 994-1000.
