Compressor is the core component of supercritical carbon dioxide(S-CO_2) power cycle. It is essential to carry out component-level experimental research on it and detect the working characteristics of the compressor and its auxiliary equipments. Building an accurate closed-loop simulation model of closed S-CO_2 compression loop is a necessary preparation for selecting the loop key parameters and establishing the system control strategy

which is also an important prerequisite for the stable operation of compressor under test parameters. In this paper

the thermodynamic model of the compressor in the test loop is studied

and the operation performance of the centrifugal compressor in S-CO_2 compression loop is predicted. Based on the conventional one-dimensional loss model of the compressor

the prediction result is compared with the experimental data in the open literatures. It finds that

the conventional compressor model has a large error under the deviating design conditions

which needs to be corrected. Therefore

flow coefficient is introduced

which is defined as the ratio of mass flow and rotation speed. Then

by taking the ratio of flow coefficient under working condition to that under design condition as the correction factor

the conventional loss model is corrected. Compared with the experimental data in Sandia National Laboratory

it can be found that the prediction results of the corrected model are highly consistent with the change trend and numerical value of the experimental values

and the maximum error does not exceed 3%

which can better predict the variable operating characteristics of the S-CO_2 compressor during operation.