This study focuses on the development of a closed-loop controlled hydraulic system designed for the efficient transport and storage of liquefied hydrogen. Given the high energy density and the environmentally friendly nature of hydrogen, the research ...
This study focuses on the development of a closed-loop controlled hydraulic system designed for the efficient transport and storage of liquefied hydrogen. Given the high energy density and the environmentally friendly nature of hydrogen, the research emphasizes the need for advanced technologies capable of handling hydrogen in its liquefied form at high pressures. The core of the system is a reciprocating plunger pump, deemed suitable for pumping liquefied hydrogen due to its ability to operate at pressures exceeding 90 MPa. This is crucial for charging vehicles' hydrogen tanks, which require gaseous hydrogen at 75 MPa. To achieve precise control over the pump operation, the study employs a double-rod hydraulic cylinder driven by a sinusoidal motion, with its displacement being continuously monitored and fed back to a hydraulic proportional directional control valve. This valve, characterized by its feedback mechanism for spool position and built-in signal amplification, ensures smooth and shock-free operation across all ports during the reciprocating motion of the pump. The paper details the specifications of both the proportional control valve and the double-rod cylinder, highlighting the importance of maintaining oil viscosity within a specified range under varying temperatures to ensure efficient operation. Through experimental setups using liquefied nitrogen, the study showcases the system’s capability to handle no-load conditions effectively, simulating the operational demands of liquefied hydrogen pumping. Conclusively, this research presents a sophisticated hydraulic system capable of meeting the high-pressure requirements for liquefied hydrogen transport and storage, promising to advance the infrastructure needed for hydrogen fueling stations. The findings contribute to the broader efforts of integrating hydrogen as a sustainable and clean energy resource, particularly in the transportation sector.