Aiming at extensive applications and frosting problems of wavy finned-tube heat exchangers and based on the phase change driving force to analyze its frosting mechanism

the frosting characateristics on wavy aluminum surfaces with different cold surface temperatures (-5-15 ℃)

air temperatures (11-17 ℃)

and air velocities (1.5-2.5 m/s) were experimentally analyzed in this study. The micromorphology of frost growth on wavy aluminum surfaces was observed. In addition

the environmental effects on frost formation were analyzed using the Taguchi experimental method. The results showed that a change in experimental conditions affected the frosting characteristics on wavy aluminum surfaces. Using a wavy plate with a wavy angle of 11.3° as an example

when the frosting time was 60 min

compared to a cold surface temperature of﹣5 ℃

the frosting weight increased by 12.20% and 31.28%

and the frost layer thickness increased by 19.95% and 47.24%

when the cold surface temperature was﹣10 ℃ and﹣15 ℃

respectively. Based on the Taguchi experimental method

when compared to the air temperature and velocity

the cold surface temperature and air relative humidity greatly influence the frosting characteristics on wavy surfaces. These analyses that were based on the Taguchi experimental method revealed that the contribution rates of cold surface temperature and air relative humidity to the frosting weight of wavy surfaces were 37.3% and 31.8%

respectively

and the contribution rates to the frost layer thickness were 61.1% and 22.6%

respectively. Compared to the air temperature and velocity

the cold surface temperature and air relative humidity had a greater impact on the frosting characteristics on wavy surfaces. It is worth noting that the contribution rate of air velocity to the frost weight was 22.6%

while the contribution rate of frost layer thickness was only 4.2%

revealing that the air velocity played a considerable role in the densification of the frost layer.