The supercritical CO2 power cycle system for waste heat recovery (WHR) of internal combustion engine (ICE) has widely been concerned as a research hotspot. And the expander is a key component in the supercritical CO2 power system. Rolling rotor expander has the following advantages: compact size, light weight, less moving parts, high stability and long service life, which qualify it a very suitable choice for engine’s waste heat recovery system. For a self-designed rolling rotor expander using supercritical CO2 as its working fluid, FLUENT software was used to simulate its internal flow field in this study, obtaining the changes of the internal pressure field and turbulent kinetic energy. The causes of local vortex in the expansion process were analyzed. Under different working conditions of the expander, the change of internal pressure and the distribution of P-V curve were observed, and the work capacity under different inlet pressure was analyzed. Results show that, the work capacity increases if the intake pressure increases within a certain range. However, if the inlet pressure keeps increasing and exceeds a reasonable limit, the local vortex in the suction process is enhanced and the pressure loss is increased and the degree of the turbulence is strengthened, which causes a certain impact on the expansion process and expander service life. The rotating speed has a great influence on the operation of the expander. These results provide guidance for the design and optimization of the supercritical CO2 expander in the future.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    CFD Simulation of a Supercritical CO2 Rolling Rotor Expander for Waste Heat Recovery System of Engines


    Additional title:

    Sae Technical Papers


    Contributors:
    Li, Daiqiang (author) / Shu, Ge-Qun (author) / Huang, Guangdai (author) / Yu, Guopeng (author)

    Conference:

    WCX World Congress Experience ; 2018



    Publication date :

    2018-04-03




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Oil-Free Axial Piston Expander for Waste Heat Recovery

    Darmedru, Antoine / Melis, Julien / Daccord, Rémi | SAE Technical Papers | 2014


    Waste heat recovery from diesel engines

    Bjoerkvist,T. / Nahab Diesel,SE | Automotive engineering | 1986


    Waste Heat Recovery In Truck Engines

    Leising, C.J. / Purohit, G.P. / Finegold, J.G. et al. | SAE Technical Papers | 1978


    Advancements in hydrogen expander airbreathing engines

    GLICKSTEIN, M. / POWELL, T. | AIAA | 1987


    Supercharged Expander to Enhance Waste Heat Recovery Through ORC-Based Recovery Unit in Vehicle Applications

    Di Battista, Davide / Fatigati, Fabio / DI BARTOLOMEO, Marco et al. | SAE Technical Papers | 2021