Compressor is the core equipment of supercritical carbon dioxide(S-CO_2) power cycle system

which runs near the critical region of S-CO_2. Therefore

the non-equilibrium condensation of S-CO_2 is easy to occur when S-CO_2 flows in the compressor

which affects the performance and reliability of the system. The experimental observation of S-CO_2 non-equilibrium condensation in the compressor is difficult

the numerical simulation is complex

and the S-CO_2 compressor design experience is also relatively lacking. Based on the recent research results

this paper summarizes the current research progress of S-CO_2 non-equilibrium condensation from the perspectives of research methods

mathematical models and experimental studies. Moreover

it points out the further research directions

such as: changing the geometry parameters of nozzle to change the volume of nucleation zone

so as to change the residence time of fluid in metastable state; improving the gas equations of state to enhance the accuracy of thermophysical properties of the working fluid in metastable state

so that the numerical simulation can be carried out accurately; using the Wilson line measured in the experiment to set the inlet conditions of the compressor in the design of S-CO_2 compressor

to construct a new safe boundary.