One of the major problems associated with crude oil storage tanks is the settling of heavy particles and formation of accumulated sludge at the bottom of the tank. In this study, the temperature distribution within a crude oil storage tank has been calculated numerically and the effects of exterior surface paint color on the tank temperature have been investigated. A thermodynamic model has been developed on the basis of the equilibrium between the liquid and solid phases to calculate the solid-phase precipitation. Employing a sedimentation equilibrium model, the deposition of the solid phase and sludge formation has been evaluated. To validate the numerical results, Khark 28th crude oil storage tank is selected as a case study and the numerical values of sludge height and oil temperature have been compared to the experimental data, where good agreement is observed. Finally, the effects of the exterior surface paint color on sludge formation of a crude oil storage tank have been investigated. The results show that applying a darker color instead of the existing one may lead to 1.5 million USD/year savings for 40 crude oil storage tanks.

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