Effect of shell on performance of heat exchanger with trefoil-hole baffle

The periodic whole cross-section model and the periodic unit duct model were established, and the differences between two models were discussed. The effects of shell wall and baffle edges on the shell side performance of the heat exchanger with trefoil-hole baffle were investigated using both models. Thermodynamics in the shell side and heat transfer coefficient of each tube in different position were discussed. It is found that disparities between the results of the two numerical models decreases with the increase of the inner shell diameter. When the shell diameter is 0.8 m, the disparity is less than 10%, which means that the effects of the shell wall and the edges of baffles become weaker. When the shell diameter is less than 0.8 m, modified correlations for the periodic unit duct model are introduced to quantitatively reveal the effects of shell wall and baffle edges on thermodynamics with the variations of the shell diameter and baffle spacing. The fluid-flow velocities at specific locations on the shell side were measured using a laser doppler velocimeter system. The accuracy of the numerical simulation method was verified by the experimental results.