Study on the Dynamic Characteristics of a Seawater Relief Valve with Spring-Chamber-Damping Used in Submersible

The seawater hydraulic variable ballast system (SHVBS) is a critical subsystem to control the submersible dive or float. The operational safety and stability of the SHVBS are ensured by the relief valve, whose dynamic characteristics significantly impact the working status of the submersible. Poor dynamic characteristics can cause vibration and noise. In this paper, the principle and structure of the relief valve with spring-chamber-damping are proposed. Using a spring chamber as a damping chamber can significantly simplify the structure and reduce the volume. Force analysis of the ball, which is used as the valve core, is conducted, and the mathematical model of the relief valve is also established. The simulation model is built by Matlab/Simulink, and the flow-pressure dynamic characteristic can be simulated, and the diameter of the damping orifice on the ball seat and the mass of the moving part in the relief valve are considered. Finally, the change trends of the relief valve's dynamic characteristics, including pressure pulsation and overshoot. The results show that the lighter the moving parts, the more conducive it is to optimize the dynamic characteristics, so the material of the ball and the ball seat is made of low-density ceramic and plastic, respectively. Meanwhile, oversized damping orifices cause pressure pulsation, while undersized damping orifices cause an increase in overshoot. The relief valve can get a better dynamic characteristic when the diameter of the damping orifice is about 0.6 mm.