Ground experimental investigation of thermodynamic vent system with HCFC123

Thermodynamic vent system (TVS) is of significance to long term on-orbit storage of cryogenic fuel. In the present study, one ground experiment is established to investigate the pressure control performance of TVS with the working fluid of HCFC123. The tank pressure variation and fluid temperature change are respectively studied in self-pressurization, injection mixing and active refrigeration phases. The refrigeration capacity supplied by TVS and fluid thermal stratification during different phases, are specially illustrated. The effectiveness of the pressure control performance by means of TVS has been proven in the present experiment. The total venting gas loss is about 17.3 kg for 16 throttling cycles. The corresponding refrigeration capacity of TVS is 1216–1415 W, with circulation volume flow of 95 L/h and throttling ratio of 16.8–18.9%. Moreover, it costs approximately 6 h for the liquid thermal stratification developing fully. While in active refrigeration phase, the vapor has the maximum temperature reduction of 9.2 °C, and the variation of the liquid temperature is limited in 2.0 °C. When compared to direct venting method, TVS has recovered more than 23.22% venting loss for 4.75 h' operation. On the whole, the effective pressure control and heat load elimination of TVS are greatly confirmed.