The heat exchanger is a key component for energy and heat transfer in industrial processes. However

when the cooling water in the heat exchanger participates in heat exchange

crystallization fouling often forms on the inner walls of the heat exchanger tubes. Ultrasonic waves can effectively reduce fouling formation. In this paper

the effect of ultrasonic waves is simulated by coupling the fluid internal pressure variations and the cavitation model with a sound pressure equation. Wall shear force is used as a link to construct the crystallization fouling model under the action of ultrasonic waves. Based on the constructed model

the fouling deposition in the heat exchanger tube with and without ultrasonic waves is compared to analyze the influence of ultrasonic amplitude and frequency in detail. The results show that when the ultrasonic frequency is 20 kHz and the amplitude is 100 kPa

the fouling resistance in the tube is reduced by 45.8%. Under the influence of ultrasonic waves

the wall shear force fluctuates periodically over time

with its average value significantly higher than that without ultrasonic waves. The thickness of the fouling layer increases gradually with the length of the pipe section. The fouling thickness decreases close to the ultrasonic inlet. In the research scope of this paper

the increase of ultrasonic frequency can weaken the scale inhibition effect. When the frequency reaches 50 kHz

the scale inhibition rate decreases by 19.9%. The increase of the amplitude enhances the scale inhibition effect. When the amplitude reaches 250 kPa

the scale inhibition rate increases by 34.9%. Additionally

the fouling thickness increases with ultrasonic frequency but decreases with ultrasonic amplitude.