推进用于抽水蓄热储能的无量纲径向透平机械模型

Abstract Accurate estimation of turbomachinery efficiency is crucial for assessing the performance of advanced energy systems , especially in innovative technologies like pumped thermal energy storage . Despite its critical role, most system-level analyses do not account for the variability of turbomachinery efficiency with system design parameters, leading to inaccurate performance predictions and suboptimal designs. Non-dimensional models stand as a promising approach to predict turbomachinery efficiency as a function of system-level variables, exhibiting greater robustness and computational efficiency compared to mean-line models. This work introduces new non-dimensional models to predict the performance of both centrifugal compressors and radial inflow turbines, addressing the limitations of existing methods by harmonizing various approaches and supplementing them with additional data from mean-line models. The newly developed models are applied to a 2 MW pumped thermal energy storage system . The results suggest that using single-stage machines limits the round-trip efficiency (RTE) due to a mismatch in optimal operating speed between charge compressor and turbine. The round-trip efficiency increases from 48.1% to 50.9% when multiple stages are employed. The results also show that larger scale system can increase efficiency by rotating at grid synchronous frequency, with a 15 MW system reaching 55.1% efficiency.