Research On Efficient Calculation Of Pipeline Batch Transportation Process Of Cold And Hot Crude Oil

In recent years,a large amount of foreign crude oil has been imported to China.Because of the differences between foreign oil and domestic oil,batch transportation is generally used for transporting cold and hot oil.Batch transportation of the cold and hot oil is a complex unsteady hydraulic and thermodynamic process.In order to ensure its safe operation,a large number of conditions are needed to be calculated and a lot of time is wasted.Because of the slow speed of the traditional simulation calculation method,in this paper,the POD model is used to realize the rapid thermodynamic calculation of the batch transportation of the cold and hot oil.The geometric model and mathematical model of the pipeline for batch transportation of the cold and hot oil are established.The calculation area is discretized by using the body-fitted coordinate.A high order model for batch transportation of the cold and hot oil is established by the combination of the finite volume method(FVM)and the finite difference method(FDM).The hydraulic and thermodynamic calculation of batch transportation pipeline is realized.The transportation process of one hot and cold oil pipeline is simulated and calculated,and its thermodynamic law is analyzed.The application process of POD reduced-order model(POD-ROM)is analyzed by a concrete example,and the calculation results of POD method and FVM are compared and analyzed.It is found that the maximum error of the temperature field obtained by the two models is no more than 0.05 ? and the average calculation speed of POD-ROM is more than 700 times that of FVM.It can be seen that POD-ROM has higher accuracy and calculation speed.The POD-ROM is applied to the thermodynamic simulation calculation of the cold and hot oil batch transportation in the Second Donglin Pipeline.Three kinds of operation conditions are calculated and analyzed.By the comparison between POD-ROM and FVM,it is found that the POD model is of better precision,and the average error of the oil temperature at the end of pipeline is 0.16 ?,the calculation speed is more than 100 times that of FVM.Through comparison with the field data,it is found that the simulation results of POD method are of high accuracy.The average oil temperature deviation of the cold oil and the hot oil is less than 1.27 ? and 1.37 ? respectively.The POD-ROM has obvious calculation advantage and can provide convenience for the hot oil pipeline which requires a large number of calculations.It is therefore necessary to extend it to other crude oil pipelines.