黏性条件下基于导叶和叶轮匹配关系的多级导叶式离心泵PAT性能预测

PAT Performance Prediction of Guide Vane Multistage Centrifugal Pumps Based on the Matching Relationship Between Guide Vane and Impeller under Viscous Conditions

在实际流程工业中,用单级蜗壳式离心泵反转作透平无法有效地从高压液体系统中回收能量,需采用多级导叶式离心泵反转作透平来回收这部分能量,而现阶段理论不能预测多级导叶式离心泵在透平工况下最优工况点性能参数。此外,离心泵作透平回收液体余压能量时,实际流道内液体往往具有一定的黏度,介质黏度的变化会导致其在透平工况下最优工况点的性能参数较介质为清水时会有差异。为研究实际工业流程中多级导叶式离心泵的选型问题,借鉴离心泵叶轮和压水室的匹配原理和ISO国际标准《输送黏性介质离心泵的性能修正》的修正方法,理论推导了黏性条件下基于导叶与叶轮匹配关系的性能预测公式,得到介质为黏性液体时泵工况与透平工况之间的流量之比与扬程之比,通过数值模拟的方法验证理论推导的准确性。结果表明,性能预测公式得到的流量之比与数值模拟方法得到的流量之比的误差在4%~6%,而扬程之比与数值模拟结果之间的误差在2%~7%。证明研究可为多级导叶式离心泵作透平用于回收黏性液体中余压能量时的选型提供依据。

In the actual process industry,the use of worm-shell single-stage centrifugal pump reversal for turbulence can not effectively recover energy from the high-pressure liquid system,the need to use multi-stage guide lobe centrifugal pump reversal for turbulence to recover this part of the energy,and at this stage the theory can not predict the multi-stage guide lobe centrifugal pump in turbulent conditions under the optimal operating point performance parameters.In addition,the centrifugal pump for turbulence recovery of liquid residual pressure energy,the actual flow channel of the liquid often has a certain viscosity,the change in the viscosity of the medium will lead to its optimal operating point in the turbulent condition of the performance parameters than the medium for clear water will be different.In order to study the selection of multi-stage guide lobe centrifugal pump in the actual industrial process,with reference to the matching principle of impeller and pressure chamber of centrifugal pump and the correction method of ISO international standard“Performance correction of centrifugal pump for conveying viscous medium”,theoretically derived the performance prediction formula based on the matching relationship between guide lobe and impeller under viscous condition,and obtained the ratio of flow rate to head between pump condition and turbine condition when the medium is viscous liquid.The accuracy of the theoretical derivation is verified by numerical simulation.The results show that the error between the ratio of flow rate obtained from the performance prediction formula and the ratio of flow rate obtained from the numerical simulation method is 4%~6%,while the error between the ratio of head and the numerical simulation results is 2%~7%.It is demonstrated that the study can provide a basis for the selection of multi-stage guide vane centrifugal pumps as turbines for recovering residual pressure energy in viscous liquids.