Performance study on plain fin filled with catalyst in a plate fin heat exchanger for hydrogen liquefaction

Abstract

In order to develop the correlations of the fin performances of the catalyst filled plate fin heat exchanger (CFPFHE) for hydrogen liquefaction, a numerical model of the plain fin filled with catalyst at 30–80 K is established. The effects of temperature, the structural parameters of the fin and catalyst layer and the operating condition on the fin performances of the fin channel are analyzed and discussed. The results show that the temperature distribution patterns and fin performances at 30–40 K and above 40 K have obvious differences. The results above 40 K can be characterized by that at 70–80 K. The sensitivity analysis shows that the distributions of sensitivity at 70–80 K and 30–40 K are similar. The heat transfer and ortho-para hydrogen conversion performances are mainly affected by the structural parameters of the fin and the operating condition, while the flow performance is mainly affected by the structural parameters of the catalyst layer. The correlations of the flow and heat transfer performances at 70–80 K and 30–40 K are obtained by fitting the data points on the response surface with more than 97% of the fitting degrees and within ±15% of the deviations. Meanwhile, the correlations of the ortho-para hydrogen conversion performance show that the mass space velocities at 70–80 K and 30–40 K should be lower than 1.25 and 7.50 kg m−3 s−1 respectively to reach the standard of the ortho-para hydrogen conversion. The correlations of the fin performances can be used as the basis of optimization design of the CFPFHE.