Evaluate the performance of the vertically upward gas–liquid two-phase flow in an airlift pump system

• The study examined the effects of submergence ratio and two-phase pipe section length on the performance of airlift pumps, providing an in-depth analysis of their operating principles and efficiency. • To the best of the authors' knowledge, there are almost no published articles on the gas lift pump two-phase pipe length. • To solve the problem that the flow model of airlift pump is limited by the requirements of flow range, this paper, building on the Stenning and Mark (1968) model, consider pipeline losses to establish a more accurate airlift pumps flow model. • The airlift pumps flow model proposed in this paper provides an explicit expression for the constant K in the Stenning and Mark (1968) model. • The model proposed in this paper not only accurately predicts the performance of airlift pumps at low gas flow rates but also maintains high precision at high gas flow rates. This paper conducts experiments on gas–liquid two-phase flow in airlift pumps (ALPs) using air–water as the medium, measuring liquid flow rates over a broad range of flow rates, and investigates the effects of submergence ratio and the two-phase pipe section length on the performance of ALPs. Evaluate the performance of ALPs under specified operating conditions. Experimental results show that liquid flow velocity initially increases with the increase in gas flow velocity and then stabilizes; the highest liquid flow velocity does not necessarily correspond to the highest efficiency. The performance of the ALPs increases with the two-phase pipe section length within a certain range of the two-phase pipe section length. However, once this range is exceeded, the performance of the ALPs is nearly unaffected by the two-phase pipe section length; the minimum gas flow velocity required to pump liquid increases as the submergence ratio decreases. This paper presents ALPs model that is independent of pipe diameter and flow range and validates it against experimental results. The model outcomes align well with the experimental data across all flow ranges. Additionally, the model effectively captures the sensitivity changes related to the two-phase pipe section length and the submergence ratio, and accurately predicts the minimum gas flow velocity required for liquid discharge under various operating conditions.