Highly loaded aerodynamic design and three dimensional performance enhancement of a HTGR helium compressor

A design study of multistage axial helium compressor of a 300 MWe high temperature gas-cooled reactor is presented in this paper. Helium compressor is characterized by shorter blades, narrow flow channels, numerous stages and longer slim rotor, which result in losses due to blade surface and end wall boundary layers growths, secondary flows and clearance leakage flows, any occurrence of flow separation and stage mismatch. Therefore, the purpose of this paper is to improve and optimize the aerodynamic design of helium compressor.The property of helium is different from that of air, so how to choose the design parameters of a helium compressor is discussed first. And then how to shorten the axial length of the helium compressor or how to decrease the number of stages for a certain pressure ratio by increasing the stage loading are investigated.The new highly loaded helium compressor of larger flow coefficient and high reaction is designed and optimized. Three-dimensional flow patterns in a helium stage are simulated with CFD software (NUMECA). Adjusting the position of blade maximum camber deflection position; redistributing radial compression work; 3D blading techniques, such as distribution spanwise relative airfoil thickness, custom tailoring airfoils and bowed stator vane to mitigate end wall boundary layers and corner separation have improved the aerodynamic performance of the first stage of helium compressor.

► A new highly loaded helium compressor of larger flow coefficient (1st stage) is simulated.
► The basic approaches are taken in the optimized design.
► The advanced 3D blading techniques have adopted to mitigate corner separation.
► The final highly loaded design has increased the pressure ratio obviously, even with high efficiency and large stable operating range.