For enhancing the film stiffness of supercritical CO_2(S-CO_2) hydrodynamic dry gas seal and reducing the additional power consumption due to the installation of heater in the seal inlet line

a new structure of S-CO_2 hydrostatic-dynamic dry gas seal with the heating of the ring body at the back of the static ring is proposed. Based on the conjugate heat transfer model

the pressure and temperature distribution of dry gas seal were simulated utilizing commercial software Fluent. The steady-state performance and flow field distribution of S-CO_2 hydrodynamic seal

hydrostatic seal and hydrostatic-dynamic seal were compared and analyzed

and the flow and heat transfer characteristics and power consumption of S-CO_2 hydrostatic-dynamic dry gas seals under different heating modes and heat temperatures were discussed. The results show that the film stiffness of the hydrostaticdynamic dry gas seal is improved more than doubled compared with the hydrodynamic dry gas seal

while the leakage rate increased significantly by 35% at the same time. The power consumption under ring heating mode is 44% lower than that under direct gas heating mode

leading to better operating economy. It provides a new idea for the structure design and auxiliary system improvement of compressor dry gas seal in S-CO_2 power generation system.