| Aiming at the existing problems of high cost of pipeline scaling cleaning and not easy to observe the descaling effect in the industrial field,this paper researches an online descaling system combining infrared detection technology and ultrasonic cleaning technology.Based on the infrared array sensor to achieve real-time temperature monitoring of the pipeline surface,and combined with temperature changes,the power of ultrasonic drive power supply is dynamically adjusted to achieve online ultrasonic descaling of pipelines.The main research contents of this thesis include.Firstly,the ultrasonic power supply for pipeline descaling was designed:its operating frequency is about 21.5k Hz,and the maximum output power of the power supply is 500W.The frequency tracking scheme is based on the HZ6686 special chip designed by our lab team,which realizes the normal driving of the ultrasonic transducer and the fast tracking of the transducer frequency.The YM32A infrared array sensor is used to monitor the change of scale thickness in the pipe in real time through the pipe surface temperature.Secondly,the heat transfer models with different shapes and fouling conditions were established.Based on COMSOL software,the heat transport characteristics of the pipeline and its fouling are analyzed by combining fluid temperature,thermal resistance distribution and pipeline shape,etc.The correspondence between the pipeline surface temperature and the thickness of the scale layer inside the pipeline is established,and the feasibility of online pipeline descaling based on the pipeline surface temperature monitoring scheme is theoretically demonstrated.Finally,the performance of the online pipeline descaling system based on the detection of pipeline surface temperature by infrared sensors is verified through experiments simulating the production line environment.The average temperature accuracy of the system reached 0.3℃,with4.7%error from the simulated average temperature measurement,and the judgment accuracy of the descaling thickness reached at least 1.2mm.the online system consumes 45W at the highest,and there is no obvious overheating phenomenon during the working process.The online descaling system can generate a maximum acoustic field intensity of 0.69W/cm~2 in water,and can achieve an average descaling rate of 89.7%and an average reduction of 22%in working time for 1.2mm and 2.6mm thickness of dirt in the pipeline,which verifies the feasibility of the descaling detection scheme in this paper. |
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