Investigation on Interaction between Geometry and Performance and Design of S-CO2 Radial Inflow Turbine’ s Vaneless Inlet Volute

Abstract

The inlet volute is one of the key components that guide the working fluid into the radial inflow turbine. It has a significant effect on the performance of the radial inflow turbine. The conventional design criteria for the vaneless inlet volute mainly focuses on the ideal gas, which does not apply to real gas cases, such as supercritical carbon dioxide(S-CO2). In this paper, an MW-class S-CO2 radial inflow turbine is studied. Firstly, the inlet volute design of the radial inflow turbine with a vaned stator is completed, and the flow in the whole machine is calculated using CFD simulations. Then, based on the inlet boundary conditions of the impellers, the vaneless inlet volute with different throat areas and cross-sectional area distributions are investigated. The results indicate that the size of the counter rotating vortexes in the vaneless inlet volute increases with the throat area increasing, and is also influenced apparently by the cross-sectional area distribution. The volute throat area has little effect on the circumferential distribution of the outlet airflow angle but changes the average value of the airflow angle. The cross-sectional area distribution of the volute influences the circumferential distribution of the outlet flow angle. The result indicates that volute with a small-scale convex profile has a uniform outlet flow field. Compared to the turbine with the vaned stator, the radial dimension of the vaneless volute turbine obtained in the final design is significantly reduced, and the total-total efficiency at the design point is 85.62%, which meets the design requirements. Moreover, it also has good performance at off-design operating conditions.

Research Advances in the Application of the Supercritical CO2 Brayton Cycle to Reactor Systems: A Review

“…Validations using coupled system component models confirmed the reliability of this approach [52]. Zhu studied a bladed SCO 2 centrifugal turbine intake volute and performed numerical simulations of the entire centrifugal turbine [53]. The results indicated a harmonious match between the designed bladed centrifugal turbine intake volute and its nozzle and impeller.…”

Numerical Evaluation in a Scaled Rotor-Less Nozzle Vaned Radial Turbine Model under Variable Geometry Conditions

“…Conventional design criteria for each turbine part (volute, stator, and rotor) focus primarily on ideal gas, but new systems under development such as hydrogen or industrial gases, such as S-CO 2 , require further research on radial turbines [27]. The use of new propulsion systems, alternative to diesel and gasoline engines, need to have a turbocharging system suitable for their needs; therefore, work on these geometries is still in progress in multiple areas.…”