Research on heat transfer characteristics of crude oil storage tank heated by jet in combination with mechanical stirring

Mechanical stirring can enhance the jet heating of storage tanks. However, the internal heat transfer characteristics during heating and the effects of different agitators are unclear. This paper simulated the heating process of single jet and three agitators under different stirring speeds, considering crude oil rheology and wax crystal latent heat, using the SIMPLE algorithm. Results show that mechanical stirring spreads jet - introduced heat across the domain, making the temperature field more uniform. The agitator B, with higher impact flow velocity, a broader velocity core, and wider reflux coverage, was most effective. After 4 - hour heating, it raised the average temperature by 0.13 °C over the single jet, reduced temperature variance by 80 %, and increased the heating rate by 12.5 %. At high speed (350 rpm), the three impellers showed little difference. At low speed (150 rpm), the agitator B also increased the minimum temperature. After 4 - hour heating, the domain's minimum temperature was 1.04 °C higher than the single jet, and 0.35 °C and 0.37 °C higher than the agitators A and C. The findings also apply to large - scale oil storage facilities and different crude oil types. Both high-speed stirring and low-speed stirring were comprehensively evaluated from various perspectives.