Measurement of transient discharge mass flow rate from a cryogenic tank during sudden depressurization

An experimental study has been conducted to determine the most practical and accurate technique that can be used for measurement of transient mass flow rate during sudden discharge of a cryogenic liquid from a storage tank. Different types of direct and indirect methods of measurement were considered. The method of relating the time rate of change of weight of the liquid in the tank to the discharge mass flow rate was found to be the most practical and reliable one. Descriptions of the flow system, the instrumentation, and the data acquisition systems are given in detail. Various tests were conducted with the proposed arrangement where combinations of different initial vapor pressures and different valve openings were used. The discharge mass flow rates for these cases were calculated from the collected data. Results of some selected cases are presented in detail together with an error analysis. Also, an attempt is made to obtain an equation which models the dynamic behavior of the liquid in the test tank. It is assumed that the solution of this equation can be used to make the necessary corrections on the load cell response.