In order to analyze the performance of the spiral groove dry gas seal considered effects of both real gas and slip flow simultaneously

the modified pressure governing equations of the seal based on the narrow groove theory by taking the effective viscosity coefficient instead of the gas dynamic viscosity and the real gas Virial state equation instead of the ideal gas state equation. N2

H2

CO2 were taken as examples. The leakage

the pressure at groove root radius and the opening force of the seal were calculated. Meanwhile

the leakage

the pressure at groove root radius and the opening force under the condition of ideal gas without slip flow

ideal gas with slip flow

real gas without slip flow and real gas with slip flow were compared

respectively. The results showed that the effect of slip flow made the leakage increase

and the pressure at groove root radius and the opening force decrease. The effect of real gas made the leakage

the pressure at groove root radius and opening force of susceptible compressed gas (Z<1) increase whereas the leakage

the pressure at groove root and opening force of non-susceptible compressed gas (Z>1) decrease. With increasing sealed pressure po

the effect of slip flow was reduced

while that of the real gas was strengthened. Under the condition of low sealed pressure

the slip flow effect was significant. On the contrary

the real gas effect played a predominant role under the condition of high sealed pressure.