Abstract:To address the issues of pressure monitoring lag and control inaccuracy in LNG storage tanks, this study investigates a VOF-based multiphase flow monitoring and control method. By integrating the gas-liquid interface tracking mechanism, the rolling optimization strategy of MPC, and the disturbance compensation capability of DDPG, an integrated "monitoring–optimization–compensation" control architecture is constructed. The VOF-WTD-WPE multi-scale fusion method is adopted to achieve mechanism-data collaborative perception, while the MPC-DDPG cooperative optimization framework handles multiple constraints and nonlinear disturbances. Experimental results show that the model reduces the mean pressure monitoring error by 85.2%, narrows the steady-state fluctuation range by 53.3%, achieves an anomaly detection sensitivity of 98.2%, and lowers the false alarm rate to 1.5%. Additionally, the specific energy consumption of the system is reduced by 30.4%, and computational resource usage is decreased by 68.7%. The results demonstrate that the proposed model significantly enhances the real-time performance and control accuracy of pressure monitoring, providing effective support for the intelligent and safe operation of LNG storage and transportation systems.