Experimental study on thermal-hydraulic characteristics of cryogenic plate-fin heat exchangers

Plate-fin heat exchangers (PFHEs) are used in diverse applications because of their superior capabilities. Recently, the demand for PFHEs has increased in cryogenic industries. Therefore, evaluating the thermal and hydraulic performances of PFHEs under cryogenic conditions is crucial for effectively designing them. In this study, the thermal–hydraulic characteristics of cryogenic nitrogen gas flowing through PFHEs were investigated experimentally. Two PFHEs with different fin geometries are used in this study. The hydraulic diameters of the PFHEs were 2.13 and 1.47 mm. The experimental ranges of the Reynolds and Prandtl numbers were 345–7800 and 0.72–0.75, respectively. From the experimental results, a heat transfer correlation based on the Diani correlation was derived in both turbulent and laminar regimes, with root mean square percentage errors of 0.68 and 6.9 % for the turbulent and laminar regimes, respectively. For hydraulic performance, the calculated pressure drop demonstrated good agreement with the experimental data, with a root mean square percentage error of 13 %.