Estimation of the residual resource of vertical cylindrical steel tanks for oil products, taking into account geometric structural deviations.

Abstract

Abstract. The article is devoted to solving a number of problems associated with determining the residual resource of cylindrical steel tanks. When studying the negative factors that affect the operational resource of the studied objects, detailed attention is paid to the geometric structural deviations that appear in the process of using these technical structures. The deviations of the outer contour of the bottom of the tank, the forming wall of the tank from the vertical at the level of the top of each belt of the wall, and the deviation of the paving of the base from the horizontal are selected as a determining parameter and are investigated. The work assumes that the forecasting of the residual resource is based on the determination of its minimum estimate by calculation. A comparison of the minimum estimate with the established permissible level of wear of the structures under study is carried out. Achieving the maximum permissible critical values of deviations below which the necessary reserve of the load-bearing target is not provided is defined as a limit state. In the absence of significant failure statistics, a probabilistic-physical approach is used to evaluate the objective technical condition and forecast the residual resource of the specified structures. Within this approach to the assessment of durability, there is a probabilistic model that uses the failure DM-distribution. The parameters of the used model are based on a physical interpretation. The main parameters taken into account are the average rate of change of the determining parameter and the coefficient of variation of the generalized degradation process. The work gives an example in which the residual and total service life of steel cylindrical tanks is determined. The results obtained during the calculations demonstrate proportionality with the permissible normative values and periods of operation specified in the regulatory documentation. The article presents the criteria for assessing the residual resource of the investigated steel cylindrical tanks, the use of which will allow reducing operating costs by increasing the intervals between repairs.