Performance and Loss Analysis of a Small-Scale Supercritical CO2 Turbine

The supercritical carbon dioxide (S-CO2) power cycle is widely applicable to the utilization of multigrade heat sources due to its high efficiency and compact structure, in which the turbine is critical to the performance of the system. In this study, the operation pattern and output performance of an S-CO2 axial turbine with a design power scale of 10 kW power are investigated by experiments and numerical simulations. The loss mechanisms and distributions are analyzed using numerical simulations and loss models. The results show that the turbine output power and efficiency are at 9.66 kW and 36.6% at the designed condition and the output performance depends on the pressure ratio and rational speed. In addition, the flow field distribution reveals that the flow separation phenomenon occurs leading to loss, with the tip clearance loss being the most significant. Furthermore, the loss model validated in this paper is proven to be competent enough to fulfill the prediction of the loss distribution under different operational conditions, which could be very promising in the design of an S-CO2 axial turbine.

Automated summary

In this study, the operation pattern and output performance of a 10 kW S-CO2 axial turbine are investigated using experiments and numerical simulations. The results show that at the designed condition, the turbine achieves an output power of 9.66 kW and an efficiency of 36.6%. The results also indicate that the turbine's performance is influenced by the pressure ratio and rational speed. Additionally, the flow field distribution reveals the occurrence of flow separation phenomenon, with tip clearance loss being the most significant.