Entropy generation of heat exchanger with helical baffles

A comparative study on the performance of fold helical baffle heat exchanger with the original sector-shaped helical baffle heat exchanger was carry out based on the entropy generation number of second law of thermodynamics with CFD numerical methods for analyzing the optimized degree of energy conversion quantity and quality of the improved heat exchanger. The result shows that the fold helical baffle heat exchanger can close the outer triangle leakage zone at the straight edge of the sector-shaped baffles, which makes the heat exchanger not only maintain a better plunger flow in the shell-side, but also form a more significant radial velocity gradient. The overall heat transfer coefficient of fold helical baffle heat exchanger increases by 30.4%-36.3% and the shell-side pressure drop increases by 36.0%-36.5%. The entropy generation number of helical baffle heat exchanger decreases with an increase in heat transfer unit number. Under different entrance flow rates, the heat transfer unit numbers of fold helical baffle heat exchanger are all greater than those of sector-shaped helical baffle heat exchanger, but entropy production numbers are less, reduced by 24.4%-28.4%. The fold helical baffle heat exchanger not only has obvious advantages in the quantity of energy conversion, but also has a significantly improvement in the quality energy conversion, that is, the degree of perfection of thermodynamic. The results are of important significance to further understand the flow and heat transfer mechanism of helical baffle heat exchanger and to guide the optimization design of helical baffle heat exchanger.