Experimental investigation on two-phase flow instabilities in long-distance transportation of liquid oxygen

摘要

Two-phase instabilities are inevitably encountered in the cryogenic transport process, which are significant for the high-efficient utilization of cryogenic fluids as well as the safe operation of cryogenic devices, especially for long distance transportation systems. An experimental study is performed on a 200-meter-long transfer system with liquid oxygen to investigate the details with respect to the cryogenic two-phase instabilities. The fluid pressure, temperature as well as flow rate along the conveying pipelines are measured, and the pipeline chill-down, tank chill-down, filling and parking steps are conducted sequentially. The results demonstrate the important role of gas forced convection for long pipelines, and reveal the flow and thermal performance of chill-down process. The system damage caused by chill-down pressure surge might be possibly avoided through properly controlling the inlet pressure of the pipeline and simultaneously chill-down efficiency can be improved. Besides, the geyser phenomenon with 8 min duration and 0.18 MPa pressure amplitude was observed in a 10-meter-high vertical pipeline during the parking process, and the consumption rate of cryogenic fluids was greatly increased.