Experimental investigation on heat transfer performance of heat exchanger with ladder-type fold baffles

Conventional plain baffles are often used in heat exchangers with helical baffles. There are two X-shaped triangular leakage zones between the two adjacent plain baffles, which decrease heat transfer performance of the heat exchanger obviously. The improved configuration of ladder-type fold baffle was proposed. Folded panels of the two adjacent ladder-type fold baffles contact closely to eliminate the triangular leakage zones and thus the shell-side flow field is improved significantly. The experimental results show that the overall heat transfer coefficient of the improved heat exchanger with ladder-type fold baffles increases by an average value of 21.4% compared with that of conventional heat exchanger with plain baffles. And the shell-side heat transfer coefficient increases by an average value of 27.3%. However, the increment in pumping power penalty due to the increase of shell-side pressure drop is 2~80 W. The thermal performance factor TEF is enhanced by 14.8%~24.2%, with an average value of 19.5%. In addition, heat exchangers with ladder-type fold baffles are convenient in localization and installation. The results of this paper are of great significance in the optimum design of the heat exchanger.