Release:2017, Vol. 3. №3
About the authors:Boris V. Grigoriev, Cand. Sci. (Tech.), Head of the Department of Applied and Technical Physics, University of Tyumen; firstname.lastname@example.org
This article presents the results of an experimental study of the temperature variation of the inner wall of a steel tank under different operating conditions. The authors provide the scheme of the experimental setup and the results of measurements of the wall temperature of the reservoir in the gas and liquid regions. The setup includes a cryocamera, a model of a vertical steel tank, soil temperature sensors and a system for heating and pumping oil.
It has been shown that the temperature of the reservoir wall in the region of the gas space near the surface of the liquid, after filling with the coolant of the reservoir by 60% and standing for 25 minutes, is close to the value of the gas space temperature; at a distance from the surface of the liquid the wall temperature is lower. It has been established that natural convection of the gas-air mixture is observed in the free space of the reservoir. For this reason, the internal surface of the tank wall is unevenly heated, which implies that the assumption of the equality of temperature of the inner wall of the reservoir and the temperature of the gas space is incorrect.
To describe the thermal operating conditions of the reservoir, a physical-mathematical model has been developed and a computer program has been created to simulate the heat exchange between the reservoir and the environment numerically. Within the framework of the model, the following assumptions are made: a boundary condition of the first kind is given at the point of contact between the soil and the metal; for the interaction of the environment with the wall there correspond boundary conditions of the 2nd and 3rd kinds; the temperature of the outer wall of the reservoir varies according to the cosine law.
Based on the results of the performed research, the comparison of the experimental and calculated data is within 0.7 °C or 2%, which indicates a correct formulation of the numerical solution.