Research Of Ultrasonic Transmission Law In Heat Exchanger

Heat exchanger is generally used in the petrochemical industry,run for a long period of time,the heat exchanger will fouling,results in the decrease of heat transfer coefficient,need to be cleaned.Offline cleaning technology which commonly used has many disadvantages,so the online cleaning technology of the heat exchanger has become a hot research topic.Due to ultrasonic descaling technology having a lot of unique advantages,some researchers have launched research on its application in the field of heat exchanger cleaning online.Existing research are focus on macro areas such as ultrasonic descaling technology can strengthen heat exchanger heat transfer effect,achieve online cleaning.Microcosmic problems which closely affect the heat transfer effect of the heat exchanger online cleaning such as ultrasound how to spread in the solid liquid phase alternating environment of heat exchanger,how to load more uniform distribution of ultrasonic wave in the heat exchanger,how to load the ultrasound makes it further transmission distance and how to install ultrasonic generator on the heat exchanger not covered for the time being.So this paper mainly studies ultrasonic transmission law in heat exchanger,including ultrasonic transmission law in heat exchanger and the influence of different ultrasonic power frequency and baffle plate when ultrasonic loading on the tube sheet;ultrasonic transmission law in heat exchanger and the influence of different ultrasonic power frequency and baffle plate when ultrasonic loading in medium;the effect of two different installation way;research on transmission mechanism of ultrasonic wave when it loading on the tube plate by Single tube model;using the curve fitting and B-P neural network model for data processing.Experimental results show : when the ultrasonic wave loads on the tube plate,the ultrasonic attenuation along the length direction are volatile,its propagation law along the direction of the heat exchange tube can use B-P neural network model to forecast,under the same frequency,the power greater,the ultrasonic cavitation effect better,under the same power,ultrasonic frequency is not the low altitude,the better the results,but 10KHz?500w>40KHz?500w>20KHz,baffle plate affects the decay curve waveform;When the ultrasonic wave load in medium,ultrasonic attenuation along the length direction as exponential function in the patterns,attenuation formula isyBxAe-=,under the same frequency,the power greater,the ultrasonic cavitation effect better,under the same power,the frequency lower,the ultrasonic cavitation effect better,baffle plate almost no effect;Ultrasonic wave loads on the tube sheet,it's actual effect is better than ultrasonic loading in tube side medium;Ultrasonic wave loads on the tube plate,the micro vibration of heat exchange tube is coupled longitudinal diameter compound movement,the main mechanism of its anti scale removal is the slip effect and the cavitation effect.