Research Of Grease Stain Thickness Measurement In The Pipeline By Ray-scanning Technology

In the process of petroleum transport,the wax deposition on the inner wall of the pipe forms grease stain,which will reduce the efficiency of petroleum transport and affect the security of petroleum transport petroleum.Then it is important to study the method for measuring the thickness and image of the grease stain to guide the cleaning job for a long-time running pipeline,which contains large grease stain on the inner wall due to the adsorption and deposition effect.In recent years,many researches and approaches based on nuclear technology has been studied.The traditional methods need some procedures include taking sample and sample preparation,which are complex and inconvenient,for different pipelines.For these phenomenon,γ-ray and neutron beams were used to achieve the measurement and contour reconstruction of grease stains by scanning transmission and prompt gammaray neutron activation in this work.For the γ-ray scanning transmission method on grease stain thickness measurement,the theoretical calculation was studied and the relationship between the scanning distance and the intensity of transmitted γ-ray was obtained.The design of the detection device,which includes the source item system,the sample and the scanning system,the detector system,was carried out with Monte Carlo code MCNP.The method was also validated with the experiments and the thickness of grease stain was obtained without calibration procedure.In addition,in order to reconstruct the contour of grease,the difference of grease thickness under different scanning angles was studied.The grease stain,which was with high content of hydrogen and contained different amount of hydrogen at different position,was detected with PGNAA technique and obtained the information of the thickness.The Monte Carlo method was used to design and optimize the measuring device including the neutron source selection and neutron collimation.Meanwhile,the simulation and experimental results acquired showed that the contour of grease was reconstructed with the method.In this work,the feasibility of determining the thickness and reconstructing the contour of grease were studied with simulation and experiments.And the application with the approaches will be developed.