The effect of minichannels on the overall heat transfer coefficient and pressure drop of a shell and tube heat exchanger: Experimental performance comparison

Abstract

Channels with small hydraulic diameters improve the overall heat transfer coefficient (OHTC) and compactness of shell and tube heat exchangers (STHEs). Intensified compactness decreases both the weight and volume of heat exchangers and allows us to use less working fluid. This study experimentally investigated the effects of minichannels on the OHTC and pressure drop performance of a STHE for five different thermal and hydrodynamic operating conditions. Present study also compared the experimental OHTC and pressure drop results of the mini-channel shell and tube heat exchanger (MC-STHE) with those of previously reported experimental results of conventional STHEs under different conditions. The MC-STHE had an OHTC of 1.1–6.6 times as high as the conventional heat exchangers. Besides, the minichannels increased the OHTC of the STHE to ∼6700 W/m2K and yielded a higher pressure drop than the macro tube heat exchangers at Re ≅ 14,000 (∀˙ = 600 L/h).