换热器内超声空化效应影响因素数值研究

对超声波参数和换热器参数对超声波空化效应影响的研究,能够找出最佳的超声波参数使其防除垢效果更好。本文利用数值计算方法研究了超声波功率、频率和换热器内介质温度以及换热管的型式对超声空化的影响。结果表明,随着超声波功率的增大,水中汽含率也增大,而且变化也相对激烈;随着频率的增加汽含率先增大后降低,20 kHz为最佳频率;介质温度越高,空化效应越强烈;管径波动较多的波纹管更有利于空化效应的产生和发展。

Numerical Study on the Factors of Ultrasonic Cavitation Effect in Heat Exchanger

Researching the influences that ultrasonic parameters and heat exchanger parameters may bring about in ultrasonic cavitation,we can find out the most proper ultrasonic parameters that make the effect of cleaning dirt better.The thesis study the influences that ultrasonic power, frequency,medium temperature in heat exchangers and the type of heat exchangers tube may bring about in ultrasonic cavitation through numerical calculation.The result show that with the ultrasonic power’s increase,the gas rate in water will increase,and the change will be relatively sharp;with the frequency’s increase,the gas rate in water will increase soon and decrease later,the most proper frequency is 20 kHz.the higher medium temperature,the stronger ultrasonic cavitation,if bellows has more changes in diameter,the development of ultrasonic cavitation will be more easy.