Performance comparison for oil-water heat transfer of circumferential overlap trisection helical baffle heat exchanger

The performance tests were conducted on oil-water heat transfer in circumferential overlap trisection helical baffle heat exchangers with incline angles of 12 degrees, 16 degrees, 20 degrees, 24 degrees and 28 degrees, and compared with a segmental baffle heat exchanger. The results show that the shell side heat transfer coefficient h(o) and pressure drop Delta p(o) both increase while the comprehensive index h(o)/Delta p(o) decreases with the increase of the mass flow rate of all schemes. And the shell side heat transfer coefficient, pressure drop and the comprehensive index h(o)/Delta p(o) decrease with the increase of the baffle incline angle at a certain mass flow rate. The average values of shell side heat transfer coefficient and the comprehensive index h(o)/Delta p(o) of the 12 degrees helical baffled scheme are above 50% higher than those of the segmental one correspondingly, while the pressure drop value is very close and the ratios of the average values are about 1.664 and 1.596, respectively. The shell-side Nusselt number Nu(o) and the comprehensive index Nu(o).Eu-zo(-1) increase with the increase of Reynolds number of the shell side axial in all schemes, and the results also demonstrate that the small incline angled helical scheme has better comprehensive performance.