Investigation on Energy Loss in Centrifugal Pump Based on Entropy Generation and High-Order Spectrum Analysis
Investigation on Energy Loss in Centrifugal Pump Based on Entropy Generation and High-Order Spectrum Analysis
复制标题
基于熵产和高阶谱分析的离心泵能量损失研究
DOI：
10.1115/1.4047231
复制
发表时间：
2020-09-01
影响因子：
2
通讯作者：
Zhang, Chenliang
中科院分区：
文献类型：
--
作者：
Cui, Baoling;Zhang, Chenliang
全开直叶片离心泵具有结构简单、高速稳定性好等优点。然而，这种离心泵内部能量损失大，效率低。不稳定流动引起的流量损失占离心泵内部能量损失的大部分，这些能量主要以压力脉动和振动的形式耗散到泵周围。为了更好地了解离心泵的水力特性和能量损失，本文采用熵产生法对离心泵内部的能量损失进行了数值分析，根据实验结果分析了不同流量下压力脉动和振动能量的分布，并用高阶谱分析研究了设计流量(Q(D))为20%时流量和能量损失之间的相关性。通过均方根(RMS)值来评估实验中的压力脉动和振动能量。熵生率的分布表明，蜗壳、间隙、舌头和叶片入口的扩散段有较大的能量损失。在设计流量(Q(D))的20%时，能量损失是由舌部附近的回流引起的，EP2处的EGR具有0.44f(N)的非线性基频。通过双谱分析和相干分析，分析了非受迫流动产生的非线性基本特征频率，发现非受迫流动在近舌区相互传递。
Full-open, straight-blade centrifugal pumps have the advantages of simple structure and high stability at high speeds. However, this type of centrifugal pump has a large internal energy loss and low efficiency. The flow loss caused by unstable flow accounts for most of the internal energy loss of a centrifugal pump, and this energy dissipates mainly to the surroundings of the pump in the form of pressure pulsation and vibration. In this study, to effectively understand the hydraulic behavior and energy loss in a centrifugal pump, the energy losses in the pump were numerically analyzed by the entropy generation method, the distribution of the energies of pressure pulsation and vibration was evaluated based on experimental results at different flowrates, and the correlation between flow and energy loss at 20% of the design flowrate (Q(d)) was investigated by high-order spectrum analysis. The energies of pressure pulsation and vibration in the experiment were evaluated by the root-mean-square (RMS) value. The distribution of the entropy generation rate (EGR) indicated large energy losses at the diffusion section of the volute, clearance, tongue, and blade inlet. At 20% of the design flowrate (Q(d)), the energy loss was caused by the backflow near the tongue, and the EGR at EP2 had a nonlinear fundamental characteristic frequency of 0.44f(n). By bispectrum and coherence analysis, the nonlinear fundamental characteristic frequencies generated by the unforced flow were analyzed, and it was found that unforced flow was transmitted to one another in the near-tongue region.