AIRSIDE PERFORMANCE OF STAGGERED TUBE BUNDLE HAVING SHALLOW TUBE ROWS

Airside performance for tube bank having N = 1 ~6 are reported in this study. Test results indicated that the heat transfer coefficients for N = 1 and N = 2 are comparable and the heat transfer coefficients increase with the number of tube row. For the same P _t, P _t the heat transfer coefficients for the tube bank containing smaller diameter tube are higher than those of larger tube diameter for N≥2 and is comparable for N = 1. Comparisons of the heat transfer performance were made with several correlations. It is found that the Gnielinski correlation gives the best predictive ability. For multiple-row heat exchangers, the predictive ability of the well-known ?ukauskas correlation is also good. But the correlation under-estimate the present I-row heat exchangers. As a consequence, a slight modification to the ?ukauskas correlation is proposed that can extend its applicability in N = 1 and Re_D < 1000. In addition, modification to the frictional performance of ?ukauskas correlation is also made. The mean deviation of the proposed frictional correlation is 11.2%.