This study investigates the slugging characteristics of the gas–liquid slug flow interface in horizontal pipes. Using air and water as the experimental media, an experimental system was established using double-parallel conductance probes in a pipe with an inner diameter of 5 cm. By capturing the transient development process of the gas–liquid interface, the slugging characteristics of the gas–liquid two-phase flow interface in different flow regions were revealed. The results show that the value of gas-phase superficial velocity has an important influence on the shape and development of the interface wave during the slugging process. When the gravity wave generated during the slugging process can propagate upstream, the slugging phenomenon is periodic, and when the gravity wave cannot propagate upstream, the slugging phenomenon is random. The experiment verified the correctness of the interface instability theory and the liquid slug stability theory, and clarified the definitions of h o and h s . In addition, the paper analyzed the influence of gas–liquid velocity on slugging distance, h o and h s , and liquid slug frequency.

The Mixed Refrigerant (MR) component is an important factor influencing the performances of natural gas liquefaction processes. However, there is a lack of systematic research about the utilization of propane pre-cooled (C3/MRC). In this paper, this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption. The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant. The power consumption of the compressor in the hybrid refrigeration process is affected by both flow and pressure ratios. Its specific power consumption can be reduced by increasing the flow and decreasing the pressure ratio at the same time. The increase in refrigerant pressure at the high-pressure end can significantly mitigate the energy loss of the heat exchanger and compressor.