Review Article

Enhancement of Heat Transfer by Ultrasound: Review and Recent Advances

Table 6

Review of vibrating structures for heat exchangers and their advantages.

ReferenceDescription of the studyFrequency, power, intensityBest and/or interesting result obtained

Benzinger et al. [87]Microstructured heat exchanger, antifouling investigations20 kHz, 35 WPulses of 1 min to break the fouling layer but fouling speed increased
Bott and Tianqing [90]Ozone + ultrasound to clean heat exchangers, axially propagated ultrasound20 kHz, 2357.8 kW m−22357.8 kW m−2, 3 × 1 min pulse/day, up to 70% reduction in biofilm thickness
Bott [88]Control of biofilm formation or biofilm removing in heat exchangers20 kHz88% reduction of biofilm growth with 10 treatments/day, 3 × 30 s at 40% amplitude
Gondrexon et al. [85]Vibrating shell-and-tube heat exchanger, experimental investigation35 kHz, 80 WOverall heat transfer coefficient increased up to 257%
Kurbanov and Melkumov [82]Heat exchanger-type for heating and refrigeration3 and 16 kHz27% increase in but other major advantages
Li et al. [91]Effects of various parameters on antiscale and scale removal.
Sedimentary speed and scale inhibition rate analysed
14–20 kHz;
0–250 W
Larger acoustic intensity is better for scale removal.
40°C best for antiscale, 50°C for scale removal. Better effect for small distances to the ultrasonic transducer
Monnot et al. [83]Cooling of chemical reactor (2.9 L), experimental and modelling800 kHz; 1.6 MHz; 20 kHz; 0–109 WMax ~ 2.04 at 800 kHz, 57.6 W
Mott et al. [89]Experimental investigation, glass tubes filled with water, standing waves20–350 kHz,
35–45 W
95.3% of biofilm removed by
2 × 30 s treatment at 20 kHz in 7 cm tubes, 87.5% at 3 × 30 s in 50 cm tubes
Tisseau et al. [84]Shell and tube heat exchanger, experimental investigation35 kHz, variable powerOverall heat transfer coefficient increase up to 250%