Elevation of the Operating Efficiency of Plate-Like Heat Exchangers in the Presence of Ultrasonic Vibration

We study the influence of ultrasonic vibration on the local corrosion and deposition of carbonates onto the surface of AISI 304 stainless steel under the conditions of heat exchange. It is shown that, in the presence of ultrasonic vibration with a power of 9 W and a frequency of 27 kHz, it is possible to shift the activation potential to the anodic side by 0.22 V (from 0.20 up to 0.42 V/SCRE). A mechanism of repassivation of pittings under the action of ultrasonic vibration is proposed. It is based on the removal of corrosion products over the zones of pitting realized to a decrease in their adhesion to the vibrating surface. It is shown that the application of ultrasonic vibration to the surface covered with a layer of carbonate deposits makes it possible to make the heat-transfer coefficient 3.8 times higher. The application of ultrasound with a power of 190 W makes it possible to prevent any deposition of scale on the clean surfaces of heat exchange.