Design and Experimental Study of Pressure Compensation System for Full-Ocean-Depth Gas-Tight Sediment Sampler

Abstract Aiming at the requirement of the full-ocean-depth (operating water depth 11000 m) manned submersible to carry out the gas-tight sampling operation of the abyss seabed sediment, a kind of full-ocean-depth carrier submersible mechanical hand-held, full-ocean-depth gas-tight sediment sampler (GTSS) with the function of pressure-retaining and coring is designed. Firstly, the volume change model of pressure compensator is established, and it is pointed out that the volume of pressure compensator is about 16.14% equal to the volume of gas-tight sediment sampler (GTSS). Secondly, the pressure compensator is analyzed and calculated, and the relationship between the precharge pressure of the pressure compensator, the nominal volume of the pressure compensator and the pressure holding effect of the gas-tight sediment sampler (GTSS) is studied. The results show that with the increase of gas precharge pressure in the pressure compensator, the final pressure of the sampler also increases. Under the same precharge pressure condition, the larger the nominal volume of the pressure compensator, the greater the final pressure of the sampler. Finally, the air tightness test method is designed by using the developed gas tightness sampler of the full-ocean-depth product, and the change of the final pressure in the gas tight sampler under different precharge pressure is observed. The test results are consistent with the simulation results, indicating the correctness of the pressure compensation system (PCS) model.