Analysis of the main influencing factors of waste heat utilization effectiveness in the tank storage receiving process of waxy crude oil under dynamic liquid level conditions

Tank receiving process as an indispensable part of the crude oil tank storage process, the study of waste heat utilization effectiveness in tank receiving process, thus reduces the frequency of tank heating and plays a key role in achieving the “dual carbon" targets of the relevant energy storage companies. This paper analyses the waste heat transfer characteristics of received oil in the tank storage receiving process under dynamic liquid level conditions. The density field inhomogeneity is innovatively adopted to reflect waste heat utilization effectiveness of the tank storage receiving process, quantitatively characterized the influencing mechanisms between the density field inhomogeneity inside the storage tank and the external dynamic thermal environment and the mixing conditions. The results show that tank storage receiving process has gone through the heat flow diffusion stage, heat flow accumulation stage and hot and cold oil mixture stage. The heat flow diffusion stage is mainly affected by convective heat transfer, the heat flow floatation behavior is caused by mixed convection and the heat flow diffusion behavior is caused by natural convection. After the newly received hot oil breaks through the original layer and form a new hot oil layer, the process enters into the heat flow accumulation stage. This stage is affected by convection in a similar way to the heat flow diffusion phase, but the natural convection on the oil continues to deepen. And the received oil waste heat utilization effectiveness by the external environmental temperature impact is deeper. With the hot oil layer continues to accumulate, the heat transfer mode is gradually transformed from convective heat transfer to heat conduction mode of heat transfer, the receiving process enters the hot and cold oil mixture stage, the cold oil layer in the tank to heat up rapidly, and the mixing temperature gradually becomes the main influencing factors of the received oil waste heat utilization. When the tank storage receiving process is over, the larger the flow rate of the received oil and the lower the temperature, the better the efficiency of the received oil waste heat utilization.