Research On Airborne Detection Device For Gas Pipeline Defects Based On Infrared Thermal Wave Phase Method

For the problem of aging and overhauling existing underground gas pipelines in cities,the use of pipeline robots to perform on-line or in-service non-destructive testing has become the mainstream.The research on pipeline robots has also been widely carried out.But there is a lack of defect inspection devices for use with robots who can be carried into pipelines and energy by robots.After reading a bunch of existing literature and results,and comprehensive analyzes to determine the main detection method,which is a method of infrared thermal wave with eddy current thermal excitation.By analyzing thermal wave theory and conduction model,infrared radiation and infrared thermal imaging technology,and eddy current thermal excitation technology,a detection method of infrared thermal wave phase pipeline defects is summarized.The method guides selecting infrared imager,hardware implement and designing algorithm in the pipeline defect detection device and other related issues.The study,meanwhile playing an important role in the quantitative analysis of defects,and based on this,the electronic part of the thermal wave phase detection device is designed,and ultimately to achieve the operating program.The robot is equipped with inspection device,in pipe application environment,the robot load capacity,it is also obtained by means discussed.And discussed obtained by the mechanical structure of the basic design requirements of the detection means.After selecting and calculating the infrared thermal imager and its parameters,the mechanical structure of the detection device was finally designed.According to the actual pipeline defects,the simulated pipeline defect specimens used to obtain the defect detection model and verification were designed and processed,and a cross-control group was designed according to the testing requirements.Then,the defect specimens were tested using the designed detection device.After obtaining a large amount of thermal phase image data,it is found through data analysis that the difference between the gray mean value of the defect and the non-defect region of the image changes with the change of the depth value of the defect.The two have a singlevalued correspondence and have a good linearity..Using this law,by fitting the experimental data to establish a depth of the flaw detection model type and slit type circular defects,display model experimental tests have established certain detection accuracy.The total length of underground pipelines in China is increasing year by year.The safety hazards posed by old pipelines urgently need to be eliminated.Online pipeline non-destructive testing technology carried by pipeline robots will also be more urgently needed.Early warning and reduction of accident rates due to pipeline leakage will be reduced.Even eliminating people and economic losses is of great significance.