Abstract：To accurately calculate the hydraulic loss of centrifugal pump and its location, improve the hydraulic performance and avoid the limitations of traditional method based on pressure drop analysis, the local entropy production method was introduced in this study on energy consumption evaluation of centrifugal pumps. The whole steady flow passage of centrifugal pump was numerically simulated based on Reynolds stress turbulent model and energy equation model, and then the local entropy production terms were defined by self-definition field functions. Taking the cases of pipe flow for air and water as example, the results calculated by the local entropy production method were highly consistent with those calculated by Darcy law, pressure drop method and energy balance method, indicating that the local entropy production method established is reliable. Meanwhile, the calculation for centrifugal pump shows that the impeller and volute casing are the main domains generating entropy production, and the irreversible energy loss generated mainly cover wall entropy production and turbulent entropy production and in the design flow condition, these two occupy 48.61% and 47.91% of the whole respectively at the most. Above all, the energy loss by the entropy production method have some errors but basically accord with those by the traditional method, indicating that this entropy production me-thod is feasible in centrifugal pump irreversible energy loss evaluation.
张永学, 侯虎灿, 徐畅, 何文萱, 李振林. 熵产方法在离心泵能耗评价中的应用[J]. 排灌机械工程学报, 2017, 35(4): 277-282.
ZHANG Yongxue, HOU Hucan, XU Chang, HE Wenxuan, LI Zhenlin. Application of entropy production method to centrifugal pump energy loss evaluation. Journal of Drainage and Irrigation Machinery Engin, 2017, 35(4): 277-282.
[1]杨敏官, 张宁, 李忠, 等. 基于 CFD 的离心泵侧壁式压水室优化设计[J]. 江苏大学学报(自然科学版), 2013, 34(1): 28-32. YANG Minguan, ZHANG Ning, LI Zhong, et al. Optimal design of centrifugal pump with tilt volute based on CFD[J].Journal of Jiangsu University(natural science edition), 2013, 34(1): 28-32.(in Chinese)[2]BEJAN A,KESTIN J. Entropy generation through heat and fluid flow[M]. New York: John Wiley & Sons Inc, 1982.[3]SPURK J H. Fluid mechanics[M]. New York: Springer-Verlag, 1997:67-74.[4]ZHANG H C, SCHMANDT B, HERWIG H. Determination of loss coefficients for micro-flow devices: A method based on the second law analysis(SLA)[C]//Procee-dings of ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer. New York:American Society of Mechanical Engineers, 2009: 545-552.[5]KOCK F, HERWIG H. Local entropy production in turbulent shear flows: a high-Reynolds number model with wall functions[J]. International journal of heat and mass transfer, 2004, 47(10): 2205-2215.[6]CHU S X, LIU L H. Entropy generation analysis of two-dimensional high-temperature confined jet[J]. International journal of thermal sciences, 2009, 48(5): 998-1006.[7]KALURI R S, BASAK T. Entropy generation due to na-tural convection in discretely heated porous square cavities[J]. Energy, 2011, 36(8): 5065-5080.[8]王松岭, 张磊, 叶学民, 等. 基于熵产理论的离心风机性能优化[J]. 中国电机工程学报, 2011, 31(11): 86-91. WANG Songling, ZHANG Lei, YE Xuemin, et al. Performance optimization of centrifugal fan based on entropy generation theory[J]. Proceedings of the CSEE,2011, 31(11): 86-91.(in Chinese) [9]GONG R Z, WANG H J, CHEN L X, et al. Application of entropy production theory to hydro-turbine hydraulic analysis[J]. Science China technological sciences, 2013, 56(7): 1636-1643.[10]Spurk D I J H, Strömungslehre[M].Berlin: Springer, 1989.[11]HERWIG H, KOCK F. Direct and indirect methods of calculating entropy generation rates in turbulent convective heat transfer problems[J]. Heat and mass transfer, 2007, 43(3): 207-215.[12]段璐, 吴小林, 姬忠礼. 熵产方法在旋风分离器内部能耗分析中的应用[J]. 化工学报, 2014, 65(2): 583-592. DUAN Lu, WU Xiaolin, JI Zhongli.Application of entropy generation method for analyzing energy loss of cyclone separator[J].CIESC Journal,2014, 65(2): 583-592.(in Chinese)[13]KOCK F, HERWIG H. Entropy production calculation for turbulent shear flows and their implementation in CFD codes[J]. International journal of heat and fluid flow, 2005, 26(4): 672-680.[14]张翔, 王洋, 徐小敏, 等. 低比转数离心泵叶轮内能量转换特性[J]. 农业机械学报, 2011, 42(7): 75-81. ZHANG Xiang,WANG Yang, XU Xiaomin, et,al. Ener-gy conversion characteristic within impeller of low specific speed centrifugal pump[J]. Transactions of the CSAM,2011, 42(7): 75-81.(in Chinese)[15]沈维道,蒋智敏,童钧耕.工程热力学[M].3版.北京:高等教育出版社,2001.[16]ZHANG J, XU C, ZHANG Y, et al. Quasi-3D hydraulic design in the application of an LNG cryogenic submerged pump[J]. Journal of natural gas science and engineering, 2016, 29: 89-100.
