Design And Research On New Balance Device Of Radial Force Of Centrifugal Pump

Centrifugal pump with double volute can balance radial force effectively under off-design operating conditions, but the flow passage is narrow and difficult to cast. In order to balance the radial force more effectively and cast the double volute easily, IH200-150-400double volute centrifugal pump was researched as a model. Optimized the double volute structure based on CFD simulation and experimental study, and designed a new device to balance radial force. The main works are as following1. Three-dimensional modeling of pump flow field with different volute structures was conducted by Pro/E, and these models were meshed by Gambit. Numerical calculation model of impeller radial force and the simulation numerical method suit for centrifugal pump is determined2. The radial force of single and double volute pump were simulated under different flow rate, and the hydraulic performance was predicted. The results show that the double volute can balance the radial force effectively under off-design conditions, but the head and efficiency were decreased in contrast to the single volute. The maximum decrease of head is1.6m and the efficiency is2.1%.3. Three double volute pumps with different baffle length were designed, and the influence of baffle length on the radial force balance was studied. The result suggests that with the length of the baffle increases, the radial force balance effect is improved, but not obviously. The double volute pump with a short baffle can remain a good radial force balance effect, although not so effective as the longer baffle. And when the baffle extending to near the tongue, the baffle length has little impact on radial force, in addition, the difficulty of casting will increase.4. Depending on the conclusion that double volute with short baffle can balance the radial force well, a new radial force balance device which features a multi-volute structure was designed and studied. The results show that multi-volute pump can balance the radial force effectively, and the direction of radial force changes indistinctively. It can balance radial force more placidly and effectively. The head and efficiency of multi-volute pump are very close to the double volute pump.5. Single volute and multi-volute pumps with three different section profiles were designed, including rectangular, trapezoidal and circular shapes. The impact of section profile on the radial force balance was analyzed. The results show that section profile has a certain impact on the radial force balance, and so dose the head and the efficiency of pump, but not obvious.6. The experiments about radial force and hydraulic performance of IH200-150-400double volute centrifugal pump were conducted. The results show that test results are close to the simulation results, which verified the numerical simulation results are reliability, and the simulation results has a certain significance to design the structural to balance radial force of centrifugal pump.