Abstract:

In this paper,first,by taking into consideration the variation of space charge density with the filling time in oil tanks in the filling process,a dynamic distribution model of electrostatic potential in vertical cylindrical oil tanks is established.Then,the effectiveness of the model is verified by comparing the results obtained by the model with the experimental ones in the literature.Finally,the proposed model is employed to analyze the dynamic distri- bution laws of electrostatic potential in three kinds of tanks respectively without filling pipeline,with middle crane tube filling and with bottom pipeline filling.The results show that (1) both the maximum spatial potential and the maximum oil-surface potential of the three above-mentioned tanks first increase and then decrease with the oil filling rate; (2) the bottom pipeline slightly affects the electrostatic potential distribution in tanks,while the middle crane tube significantly reduces the potential; and (3) with the diameter increase of the middle crane tube,the maximum spatial potential decreases at constant filling flux but increases at constant filling velocity.This research provides references for the selection of transportation conditions and parameters and helps to reduce the electrostatic risk du- ring the filling of oil into tanks.

Key words: oil tank, space charge density, electrostatic potential, dynamic distribution, model