Background: Supercritical water reactor (SCWR) is the only one that uses light water as a coolant among all fourth generation nuclear reactors. Purpose: This study aims to investigate the characteristics of supercritical water heat transfer in various pipelines. Methods: The models of rectangular

triangular

circle and annular channels are employed

with equivalent diameters of 2 mm

3 mm and 5 mm for each of them. Based on these models

heat transfer charactersistics of supercritical water in different shape channels at certain mass flow and fluid velocity were calculated via ANSYS CFX. Results: There are two situations for the same equivalent diameter: in the condition of constant mass flow rate

the heat transfer property of circle channel outperforms other three types of channels

and the smaller equivalent diameter channels

the better of the heat transfer. In constant fluid velocity condition

the heat transfer property of annular channel presents best performance over others

and the smaller equivalent diameter channels

the better of the heat transfer in subcritical condition whilst the bigger equivalent diameter channels

the better of the heat transfer in supercritical condition. Conclusion: Compared with the experimental results

the model can provide a certain reference for the design of supercritical water reactor. Abstract