The model of pressurization rate in cryogenic tank with liquid nitrogen as the working medium was deduced from thermal analysis of the tank

two working conditions in experiment were set up to verify the model. Then experiment was mainly carried out contrastively in direct venting mode

venting mode and parallel mode to measure ullage pressure and venting rate of vapor in the storage tank

the masses of venting vapor of three models were compared

the TVS(thermodynamic venting system) efficiency of different models within pressure control range during single cycle was analyzed. Results of experiment showed that the vapor parallel model had obvious advantages on mass of venting vapor and depressurization rate of ullage than other models

and the venting mass of vapor in parallel model could reduce 97% than that in venting.