Performance analysis and optimal design based on dynamic characteristics for pressure compensated subsea all-electric valve actuator

Subsea Christmas trees are critical pieces of equipment in subsea production systems, and the main components of subsea Christmas trees are all-electric valves and actuators. A pressure compensated valve actuator was proposed in this paper, which substantially reduced the high-pressure hydraulic resistance during valve closure. According to the dynamic characteristics of this valve actuator under certain volume constraints, a performance optimization method was further proposed. To minimize the fail-close time of the valve actuator and minimize the resultant vibrations, five design parameters of the valve actuator were optimized. Relation curves of the geometrical parameters of the actuator with respect to the fail-close time and gate terminal speed were acquired with MATLAB/Simulink software. According to the optimization results, the valve and its actuator were fabricated. The horizontal and vertical accelerations under valve fail-close event were obtained through vibration experiments. The experimental results indicated that the fail-close time of the valve was basically identical to the theoretically calculated value and that the end vibrations were within the allowable range. These results verify the correctness of the optimization method proposed in this paper and show that the designed pressure compensated valve actuator has sufficient safety and can be applied to Subsea Christmas trees.