Study On Structure Design And Thermal Insulation Performance Of Composite Energy Storage Pipeline

Under the national energy dual carbon strategic goal,the oil field production operation in the process of consumption reduction is imminent.Adopting effective insulation technology for long distance pipeline can not only guarantee the safety of production and operation,but also is one of the key links of energy saving management.A composite energy storage pipeline with phase change materials(PCM),proposed based on the concept of phase change energy storage,not only has good thermal insulation performance during steady-state operation,but also can use the phase change energy release characteristics of phase change materials to adjust the heat loss of crude oil and improve the thermal insulation performance of the pipeline,so as to ensure the stable transportation of crude oil.In this paper,the composite energy storage pipeline with PCM was taken as the research object.Considering the phase state characteristics of phase change materials,combined with the partition heat transfer description theory of crude oil porous medium,the heat transfer model of composite energy storage pipeline was established.The finite volume method was used to discrete the governing equation,and fluent software was used to carry out numerical simulation.Combined with the existing experimental data of crude oil phase transition and PCM phase transition,the model was used to solve the problem.After comparison,the relative errors were less than 5%,which proves that the model and solution method established in this paper were suitable for the study of thermal insulation performance of composite energy storage pipeline.The effective parameters of composite layer of pipeline were determined by steady-state heat conduction theory,and the reasonable structure of pipeline was given.The heat transfer characteristics of typical composite pipeline were analyzed by numerical simulation method,and the thermal insulation performance was evaluated.The influence analysis of physical properties of phase change materials on thermal insulation performance was carried out.Based on orthogonal experiment method,the effective time of thermal insulation was taken as the target,and the sensitivity of influence of temperature zone,latent heat value and proportion of PCM phase change was determined.Considering the effect of natural convection in the process of phase transformation,combined with the cascade theory,the cascade structure design of energy storage composite pipeline was carried out,and its thermal insulation performance was significantly improved compared with conventional energy storage pipeline.The phase change heat transfer analysis of the composite layer was carried out for the restart condition,and the law of PCM phase change energy storage was clarified.This study can provide a theoretical basis for the application of composite energy storage pipeline in oilfield engineering.