Structural Optimization and Performance Analysis of Gravity-Enhanced Gas–Liquid Hydrocyclone

To address the challenges of low gas–liquid separation efficiency and poor operational stability under high gas–liquid ratio conditions, a novel gravity-enhanced gas–liquid hydrocyclone was proposed based on the principles of gravitational settling and cyclonic separation. By combining numerical simulation, experimental design, and laboratory experiments, the optimization of key structural parameters of the gas–liquid hydrocyclone, including the cone-end length of the overflow outlet, was systematically investigated. A multivariate regression model describing the relationship between the structural parameters and gas–liquid separation efficiency was established, and the optimal combination of structural parameters was determined. The influences of different inlet gas volume fractions and underflow-to-overflow split ratios on the internal flow field characteristics, gas–liquid phase distribution, and separation performance of the hydrocyclone were systematically investigated. The results show that the optimal separation efficiency reached 95.51% when L1 = 35 mm, D2 = 13.767 mm, and L2 = 320 mm, which was 1.11% higher than that obtained before optimization. The separation efficiency of the hydrocyclone decreased with increasing inlet gas volume fraction. The main separation region was concentrated in the cyclonic separation zone beneath the overflow outlet, whereas the pressure at the overflow outlet reached a maximum value of 0.40 kPa and subsequently remained nearly constant at an inlet gas volume fraction of 80%. The pressure field and gas–liquid distribution characteristics were significantly altered with increasing lower overflow split ratio, resulting in enhanced aggregation of the central gas core. The numerical simulation results were in good agreement with the experimental data, with the maximum and average errors being 4.63% and 3.39%, respectively. This study provides new insights and technical guidance for the structural innovation and parameter optimization of gas–liquid separation equipment under high gas–liquid ratio conditions.