Design of hydraulic system for autonomous sampler at deep-sea

Deep-sea is the last part of ocean unexplored by human, which is rich not only in oil and gas resources but also in mineral and biological resources. To date, deep-sea exploration has become one of the international research focuses and frontiers. Pressure-retaining sampler is the important equipment used for collection of high-fidelity fluid samples at deep-sea, called sampler for short, which is the foundation and guarantee for deep-sea exploration. The existing sampler usually needs some auxiliary equipment, such like winch or submersible, to complete the actions of diving, sampling and retrieving. With these auxiliary equipment involved, the whole sampling actions suffer from long working hours and expensive cost, which limits the further application of samplers. Our research team aims to develop an autonomous sampler with capabilities to automatically sample fluid, retain pressure and return to the mothership. With this aim, this article presents a hydraulic system for autonomous sampler, which could keep the pressure difference between ports of sampling valve at a small level. With a case of a sampling volume of 500mL, a sampling depth of 6000 meters and a diving speed of 1m/s, a simulation model built in AMESim environment is carried out. The results show that this hydraulic system could get a short sampling time, a high accuracy of sampling depth and a sampling valve with a small driving force and a small throttling effect.