Numerical investigation on the performance of impeller back seal configuration in a supercritical CO2 radial-inflow turbine

Radial-inflow turbine is a core component in supercritical CO2 (SCO2) Brayton cycle. The leakage from the nozzle outlet towards the impeller back brings a great challenge to the efficiency and security of the power system. In this paper, the labyrinth seal (LS) and dry gas seal (DGS) are arranged on the impeller back of a SCO2 radial-inflow turbine and the influence on the comprehensive performance is investigated. Results demonstrate that both LS and DGS configurations can significantly reduce leakage of the impeller back and DGS configuration performs better. Compared with the configuration without leakage, the power and efficiency of DGS configuration are only reduced by 0.27% and 0.35% respectively. The seal clearance and the inlet width have a greater effect on LS configuration. The thermo-mechanical seal deformation values of DGS configurations are all less than 8 μm, which verifies the feasibility. Finally, a novel combined seal configuration with both LS and DGS is proposed and excellent performance is achieved, providing a potential approach for the sealing problem of SCO2 radial-inflow turbine.

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Numerical Analysis of Labyrinth Seal Performance for the Impeller Backface Cavity of a Supercritical CO2 Radial Inflow Turbine

Computer Modeling in Engineering & Sciences ◽

10.32604/cmes.2021.014176 ◽

2021 ◽

Vol 126 (3) ◽

pp. 935-953

Author(s):

Jinguang Yang ◽

Feng Zhao ◽

Min Zhang ◽

Yan Liu ◽

Xiaofang Wang

Keyword(s):

Numerical Analysis ◽

Supercritical Co2 ◽

Labyrinth Seal ◽

Radial Inflow Turbine

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Design of a Centrifugal Compressor Stage and a Radial-Inflow Turbine Stage for a Supercritical CO2 Recompression Brayton Cycle by Using 3D Inverse Design Method

Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy ◽

10.1115/gt2017-64631 ◽

2017 ◽

Author(s):

Jiangnan Zhang ◽

Pedro Gomes ◽

Mehrdad Zangeneh ◽

Benjamin Choo

Keyword(s):

Centrifugal Compressor ◽

Supercritical Co2 ◽

Design Method ◽

Ideal Gas ◽

Inverse Design ◽

Brayton Cycle ◽

Real Gas ◽

Radial Inflow Turbine ◽

Inverse Design Method ◽

The Ideal

It is found that the ideal gas assumption is not proper for the design of turbomachinery blades using supercritical CO2 (S-CO2) as working fluid especially near the critical point. Therefore, the inverse design method which has been successfully applied to the ideal gas is extended to applications for the real gas by using a real gas property lookup table. A fast interpolation lookup approach is implemented which can be applied both in superheated and two-phase regimes. This method is applied to the design of a centrifugal compressor blade and a radial-inflow turbine blade for a S-CO2 recompression Brayton cycle. The stage aerodynamic performance (volute included) of the compressor and turbine is validated numerically by using the commercial CFD code ANSYS CFX R162. The structural integrity of the designs is also confirmed by using ANSYS Workbench Mechanical R162.

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Optimization of Supercritical CO2 Brayton Cycle for Simple Cycle Gas Turbines Exhaust Heat Recovery Using Genetic Algorithm

Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy ◽

10.1115/gt2017-63696 ◽

2017 ◽

Author(s):

Akshay Khadse ◽

Lauren Blanchette ◽

Jayanta Kapat ◽

Subith Vasu ◽

Kareem Ahmed

Keyword(s):

Genetic Algorithm ◽

Mass Flow Rate ◽

Flow Rate ◽

Supercritical Co2 ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Brayton Cycle ◽

Exhaust Heat ◽

Exhaust Heat Recovery

For the application of waste heat recovery (WHR), supercritical CO2 (S-CO2) Brayton power cycles offer significant suitable advantages such as compactness, low capital cost and applicable to a broad range of heat source temperatures. The current study is focused on thermodynamic modelling and optimization of Recuperated (RC) and Recuperated Recompression (RRC) S-CO2 Brayton cycles for exhaust heat recovery from a next generation heavy duty simple cycle gas turbine using a genetic algorithm. The Genetic Algorithm (GA) is mainly based on bio-inspired operators such as crossover, mutation and selection. This non-gradient based algorithm yields a simultaneous optimization of key S-CO2 Brayton cycle decision variables such as turbine inlet temperature, pinch point temperature difference, compressor pressure ratio. It also outputs optimized mass flow rate of CO2 for the fixed mass flow rate and temperature of the exhaust gas. The main goal of the optimization is to maximize power out of the exhaust stream which makes it single objective optimization. The optimization is based on thermodynamic analysis with suitable practical assumptions which can be varied according to the need of user. Further the optimal cycle design points are presented for both RC and RRC configurations and comparison of net power output is established for waste heat recovery.

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Numerical investigation on the leakage characteristics of stepped labyrinth seal

2016 IEEE International Conference on Aircraft Utility Systems (AUS) ◽

10.1109/aus.2016.7748137 ◽

2016 ◽

Cited By ~ 1

Author(s):

Tong Fei ◽

Wang Yehao ◽

Zhu Hongtao

Keyword(s):

Numerical Investigation ◽

Labyrinth Seal ◽

Leakage Characteristics

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A Novel Solar Receiver for Supercritical CO2 Brayton Cycle

Energy Procedia ◽

10.1016/j.egypro.2019.01.099 ◽

2019 ◽

Vol 158 ◽

pp. 339-344 ◽

Cited By ~ 4

Author(s):

Liang Teng ◽

Yimin Xuan

Keyword(s):

Supercritical Co2 ◽

Brayton Cycle ◽

Solar Receiver

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Preliminary prospects of a Pumped Thermal Energy Storage (PTES) based on a supercritical CO2 Brayton cycle

10.31224/osf.io/zuct2 ◽

2021 ◽

Author(s):

Karin Astrid Senta Edel ◽

František Hrdlička ◽

Václav Novotný

Keyword(s):

Energy Storage ◽

Thermal Energy ◽

Thermal Energy Storage ◽

Supercritical Co2 ◽

Storage Systems ◽

Renewable Energy Sources ◽

Brayton Cycle ◽

Term Energy ◽

Weather Changes

As part of the change towards a higher deployment of renewable energy sources, which naturally deliver energy intermittently, the need for energy storage systems is increasing. For compensation of disturbance in power production due to inter-day to seasonal weather changes, long-term energy storage is required. In the spectrum of storage systems, one out of a few geographically independent possibilities is the storage of electricity in heat, so-called Carnot-Batteries. This paper presents a Pumped Thermal Energy Storage (PTES) system based on a recuperated supercritical CO2 Brayton cycle. The modelled system provides a round-trip efficiency of 38.9%.

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