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Hydraulic Power Unit for 900 bar Liquid Hydrogen Pump
Y. B. Ham(함영복),Tahseen Kanwal(타신),M. A. Trimzi(모지즈),B. C. An(안병철),H. U. Kim(김홍욱),J. H. Park(박중호),S. N. Yun(윤소남) 유공압건설기계학회 2020 유공압건설기계학회 학술대회논문집 Vol.2020 No.12
A conceptual driving mechanism to run a 900 bar liquid hydrogen pump is proposed in this paper. The design of 3 types of power unit mechanisms to drive pumps is a hydraulic power pack, servo valve power pack, and electro-hydraulic actuator (EHA) compact power unit. It is recommended to isolate the hydraulic power pack from the pump for safety, but if the safety of electronic devices is ensured, it can be integrated into a compact size. In addition, the merits and demerits of these 3 hydraulic power units for the pumping of liquid hydrogen are explained. In addition, the effect of using different types of control valves to configure the hydraulic circuit and actuator is proposed. In the future, it is expected that a suitable warm end (one end of the cryogenic reciprocating pump is called warm end) can be configured by applying this paper.
Dynamic Testing of Check Valve for Cryogenic Pump
Tahseen Kanwal(타신),M. A. Trimzi(모지즈),B. C. An(안병철),H. U. Kim(김홍욱),J. H. Park(박중호),Y. B. Ham(함영복) 유공압건설기계학회 2021 유공압건설기계학회 학술대회논문집 Vol.2021 No.11
Check valves are an important component in any hydraulic system. Cryogenic liquids have very low viscosity and also at cryogenic temperature, material shrinks and hardened which increases the sealing gaps dramatically. In this article, we discuss the relation between the flow rate and pressure drop for the check valve used in a high-pressure cryogenic pump. Also, we did a simulation to check the leak and analyze the check valve with and without spring at two different testing conditions: normal closed and with the varying flow direction. We found from the simulation that leakage in the normally closed position is almost zero even at high pressure which is quite different from the real scenario. This result is due to the ideal conditions used by simulation software. We also shown quantitatively that time to change of direction of flow is more for high pressure and it is low as the frequency of proportional directional control valve changes.