Optimal hydraulic design of an ultra-low specific speed centrifugal pump based on the local entropy production theory

The ultra-low specific speed centrifugal pump has been widely applied in aerospace engineering, metallurgy, and other industrial fields. However, its hydraulic design lacks specialized theory and method. Moreover, the impeller and volute are designed separately without considering their coupling effect. Therefore, the optimal design is proposed in this study based on the local entropy production theory. Four geometrical parameters are selected to establish orthogonal design schemes including blade outlet setting angle, wrapping angle volute inlet width, and throat area. Subsequently, a 3D steady flow with Reynolds stress turbulent model and energy equation model is numerically conducted and the entropy production is calculated by a user-defined function code. The range analysis is made to identify the optimal scheme indicating that the combination of local entropy production and orthogonal design is feasible on pump optimization. The optimal pump is visibly improved with an increase of 1.08% in efficiency. Entropy production is decreased by 16.75% and 6.03% in impeller and volute, respectively. High energy loss areas are captured and explained in terms of helical vortex and wall friction, and the turbulent and wall entropy production are respectively reduced by 3.82% and 14.34% for the total pump.

[1]  L. Duan,et al.  Application of entropy generation method for analyzing energy loss of cyclone separator , 2014 .

[2]  Jinya Zhang,et al.  Numerical analysis of entropy production on a LNG cryogenic submerged pump , 2016 .

[3]  H. Herwig,et al.  Local entropy production in turbulent shear flows: a high-Reynolds number model with wall functions , 2004 .

[4]  Lei Tan,et al.  Multiparameter and multiobjective optimization design of centrifugal pump based on orthogonal method , 2017 .

[5]  Hyun Bae Jin,et al.  Spiral Casing of a Volute Centrifugal Pump - Effects of the Cross Sectional Shape - , 2013 .

[6]  Dazhi Pan,et al.  NUMERICAL INVESTIGATION OF BLADE DYNAMIC CHARACTERISTICS IN AN AXIAL FLOW PUMP , 2013 .

[7]  Zhang Lei.  Effect of Abnormal Blade Incidence on Internal Entropy Generation in Axial-flow Fans , 2012 .

[8]  Zhongli Ji,et al.  The flow pattern and entropy generation in an axial inlet cyclone with reflux cone and gaps in the vortex finder , 2016 .

[9]  Bai Dong-an.  Optimal design of ultra-low specific speed centrifugal pump for LRE , 2011 .

[10]  Zhongli Ji,et al.  Entropy generation analysis on cyclone separators with different exit pipe diameters and inlet dimensions , 2015 .

[11]  Sunsheng Yang,et al.  Research on Pump Volute Design Method Using CFD , 2011 .

[12]  Heinz Herwig,et al.  Local entropy production in turbulent shear flows: A tool for evaluating heat transfer performance , 2006 .

[13]  Yi Zhen-qin.  Study on Super-low Specific Speed Centrifugal Pump , 2008 .

[14]  Qi Xue-yi.  Impact of impeller type on performance of high-speed centrifugal pumps with ultra-low specific-speed , 2009 .

[15]  H. Herwig,et al.  Entropy production calculation for turbulent shear flows and their implementation in cfd codes , 2005 .

[16]  A. Bejan.  Advanced Engineering Thermodynamics , 1988 .

[17]  Ji Pei,et al.  Effects of distance between impeller and guide vane on losses in a low head pump by entropy production analysis , 2016 .

[18]  Yongxue Zhang,et al.  A CFD study of IGV vane number on hydraulic characteristics and pressure pulsation of an is centrifugal pump , 2017 .

[19]  Ji Pei,et al.  Cavitation optimization for a centrifugal pump impeller by using orthogonal design of experiment , 2017 .

[20]  Fei Long,et al.  Non-Overload Design of Low Specific Speed Submersible Pump , 2010 .

[21]  Jinya Zhang,et al.  Quasi-3D hydraulic design in the application of an LNG cryogenic submerged pump , 2016 .

[22]  Young-Seok Choi,et al.  Design techniques to improve the performance of a centrifugal pump using CFD , 2015 .

[23]  Hucan Hou,et al.  A numerically research on energy loss evaluation in a centrifugal pump system based on local entropy production method , 2017 .

[24]  Hucan Hou,et al.  The Optimal Hydraulic Design of Centrifugal Impeller Using Genetic Algorithm with BVF , 2014 .