Experimental investigation on enhanced heat transfer of vertical condensers with trisection helical baffles

•Trisection helical baffles are introduced for vertical condenser enhancement.•Condensation in short-section and intermediate drainage is applied in new schemes.•Helical baffles with liquid dam and drainage gaps can promote condenser performance.•Dual-thread baffle scheme is superior to that of single-thread one by about 19%.•Condensation enhancement ratio of helical schemes is 1.5–2.5 over segment one.

The vertical condensers have advantages of small occupation area, convenient in assemble or dismantle tube bundle and simple structure etc. However, the low heat transfer performance limits their applications. To enhance the heat transfer, a novel type of vertical condensers was designed by introducing trisection helical baffles with liquid dams and gaps for facilitating condensate drainage. Four configurations of vertical condensers with trisection helical baffle are experimentally studied and compared to a traditional segment baffle condenser. The enhancement ratio of trisection helical baffle schemes is about 1.5–2.5 and the heat transfer coefficient of the dual-thread trisection helical baffle scheme is superior to that of the single-thread one by about 19%. Assistant by the theoretical study, the experimental data is simulated and the condensation enhancement mechanisms by applying trisection helical baffle in vertical condenser are summarized as condensate drainage, short tube construct and reduce steam dead zone functions of the helical baffles.