Active Pressure-Compensation Technology for Deep-Sea Fluid Samplers

Decompression presents a significant challenge in ensuring the reliability of deep-sea samples. To address this issue, the current study introduces a precise active pressure-compensation technology adaptable to diverse deep-sea fluid samplers. Leveraging this technology, an active pressure compensator is also developed. The flow rate required to maintain pressure during sample recovery is determined through theoretical calculations. Based on this flow requirement, a cam piston pump—the most important component of the compensator—is designed. Furthermore, a control circuit is devised for the active pressure compensator to regulate pressure during sample recovery. Laboratory experiments verify the flow output performance and mechanical efficiency of the cam piston pump at 60 MPa. Subsequently, a pressure-maintaining sampler is constructed and tested within an extra-high pressure test chamber. Preliminary results indicate that at depths of up to 6000 m, the proposed active pressure-compensation technology can maintain sample pressures at over 99% of their in situ pressures, thereby enhancing sample quality.