Study On The Electrostatic Accumulation Characteristic Of Liquid Hydrogen During Flowing And Storage

With the rapid development of the space industry and energy industry, cryogenic fluids such as liquid oxygen, liquid hydrogen and liquefied natural gas(LNG) are more and more widely applied. In the process of conveying, insulating fluids carry static electricity because of the friction with the surface of the pipe and their good electrical insulation behavior. Static accumulation of fluid, which attracted great attention, has become the key factors influencing the industrial safety. Fluid charged problem involves multiple subjects such as fluid mechanics, electrostatics and thermodynamics, so the further study of this problem is of important theoretical and practical significance.This paper, based on study of the theory, proposes a calculation model of wide applicability and verifies the accuracy of the theoretical model through comparing the theoretical results with experimental data. Then the model is applied to the actual transport of liquid hydrogen and guidance for it is put forward according to the results.First of all, this paper introduces the research situation and achievements of the fluid static characteristics on the basis of literature investigation and then expounds the basic mechanism and influence factors of fluid charged problem. Furthermore, mathematical model of electrostatic charge density in pipe flow is built. According to the characteristics of flow in pipe, the equation is solved by difference scheme. In order to verify the accuracy of the calculation model, the experimental methods and content are designed and a test bench is built with reference to the rotating disk system to test flow electrification rate. Formation and distribution of electrical potential of low conductivity hydrocarbon product and liquid hydrogen in a tank are studied.The results of theoretical calculation model are consistent with the experimental ones, which confirming the applicability of the theoretical calculation model for research of fluid charged problem. Based on it, the model is applied to study the static electricity characteristics of liquid hydrogen. Guiding measures for transport and storage of liquid hydrogen to reduce the electrostatic hazard is obtained.