关键词: 石油, 氢, 储罐, 静电电位, 安全

Abstract: Static electricity can be generated at the interface between a fluid and a solid surface. Hydrocarbon products as well as liquid hydrogen in chemical and energy industry are of low conductivity, inflammable and explosive, which enables the static charge easily accumulated, resulting in high electric potentials and electric fields during its transportation and storage. To avoid safety hazard due to sparks of sufficient energy for an explosion to occur inside a tank, this paper studied the formation and distribution of electrical potential of some typical hydrocarbon products and liquid hydrogen in cylindrical vessels. Poisson equation and Laplace equation were solved by using Bessel function to get the potential value distribution of liquid and gas in the tanks. The impact parameters such as tank structure, fluid properties and charge density to the potential were analyzed. The potential variation behavior against the above parameters was obtained. It was found that the maximum static potential appears at about 72% of the liquid level/height from the bottom instead of the liquid-gas interface. The calculations also showed that the potential reaches its crest value for each fluid studied when the filling rate is 65%-75% of the full capacity. Some suggestions were given for design of low conductivity fluid tanks to avoid high electric potential safety hazard.

Key words: petroleum, hydrogen, tank, electrostatic potential, safety