The influence of the number of guide vane blades on the pressure and axial force distribution of the first stage impeller of LNG submersible pump was studied by CFD technology.Three kinds of blade numbers of 7,8 and 9 were designed for the first and third stage guide vanes at the same time.The K-epsilon turbulence model was used to simulate the multi-condition numerical simulation,and the liquid nitrogen working fluid was used to verify the relevant external characteristics test.The pressure distribution and axial force characteristics of the first stage impeller inside the LNG pump were obtained.The results show that the total axial force of the submersible pump is the smallest when the number of guide vanes is 8,and the overall efficiency of the pump is the best.The axial force acting on the back cover plate on the first stage impeller is greater than that on the front cover plate.When the number of guide vanes is 8,the axial force of the front and rear cover plates of the first stage impeller is the smallest and the pressure distribution is the most uniform.When the number of guide vanes is 9 and the number of impeller blades is 9,there will be a common frequency doubling during operation.The vibration accumulates on the same frequency doubling and induces resonance,resulting in the maximum axial force of the front and rear cover plates.The axial force of the front cover plate of the impeller is increased by 3.45%on average compared with other schemes.The absolute value of the axial force of the rear cover plate increases by 1.88%on average.In summary,the hydraulic efficiency of the submersible pump is optimal when the number of guide vanes is 8.
关键词
LNG/潜液泵/导叶叶片数/首级叶轮/轴向力平衡/CFD
Key words
LNG/submersible pump/the blade number of guide vane/the first-stage impeller/axial force balance/CFD
维普
万方数据