Design of axial auxiliary impeller in external circulation cooling system of large pump
Jia Yun1, Jia Yanwei2, Wei Xianzhu3
1.School of Energy Science and Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China; 2.Harbin Electric Power Equipment Co. Ltd., Harbin, Heilongjiang 150066, China; 3.State Key Laboratory of Hydropower Equipment, Harbin, Heilongjiang 150040, China
Abstract：In order to design and validate the auxiliary impeller required by the cycle power of the oil-lubricated external circulation cooling system on the reactor coolant pump′s bi-directional thrust bearing, the CFD method is applied to present a numerical analysis for the pressure feature and flow rate within the oil impeller. The objective is to demonstrate the vector distribution of the relative velocity on the center surface of the flow path, and to verify the possibility of creating any flush angle from the inlet flow of the vane, the pros and cons of the vane shape design and how well it functionally matches the vane. The numerical analysis intuitively reflects the flow parameters and patterns generated by the designed shape of the vane, indicates the fact that the velocity at the vane′s inlet mainly affects the tangent angle; thus, effectively lowers the damaging impact on any system devices located adjacent to the rear outlet of the vane. Through simulation of the oil-lubricating circulation, numerical analysis are comparatively analyzed with the testing results, for all 5 complete working processes, deviations are uniformly less than 5% and precisely satisfied lubricating oil′s flow, head, zero-impact on flows and other operating requirements. This paper concludes the practical application of a simplified numerical analysis and reasoning could replace the repetitive testing employed in the traditional design process for axial auxiliary impellers. It has been successfully applied in the design of reactor coolant pump.
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