Experimental determination of thermal contact resistance of helically serrated finned tubes with different bonding extents

In this article, helically serrated finned tubes, which are generally used in heat recovery steam generator (HRSG) boilers in combined cycle power plants, are experimentally studied, in order to find their thermal contact resistance (TCR) values in different conditions. Temperature, air velocity and fin-to-tube bonding extent were the variables and a precise methodology was performed to extract the TCR values from the obtained data. The results showed that TCR decreases by increasing the air velocity and the bonding extent, but temperature has a negligible effect on it. Moreover, the TCR values showed a good consistency in order of magnitude when compared to similar systems studied before.