Comprehensive experimental and modeling analysis of helically-wound coiled vaporizer

This article concerns energy transformation and considers the process of cryogenic liquid regasification, which is a key aspect of the optimal use of alternative fuels in transport. The research presented in the article uses liquid nitrogen as a proxy for cryogenic fuel and focuses on the risk of freezing of the heating fluid in heat exchangers. The main objective of this article is to analyze the existing boiling correlations and to select the best correlation for regasification of cryogen based on their comparison with experimental measurements. The second objective is to identify the potential risk of freezing of the heating fluid. The article presents comprehensive research including theoretical analyses, modeling and experimental measurements concerning the problem of regasification in an original helical heat exchanger designed for the purpose of regasification of fuel for road transport. The study includes 2D modeling using different boiling correlations, 3D CFD modeling of the entire heat exchanger and experimental measurements for different cryogen and heating fluid mass flows. The obtained results showed that the modified flow boiling correlation based on the Miropolski model gave the best comparison with the experimental results. The 3D CFD modeling showed that the proposed heat exchanger design provided the proper distribution of the heating medium flow and minimized the occurrence of dead zones, which were particularly susceptible to freezing. The results and methodology presented in the article can be used for the complete design of heat exchangers dedicated to the regasification of cryogenic liquids. • Helically-wound coiled heat exchanger for LNG regasification was designed. • 2D model of HX operation has been developed. • Different flow boiling correlations have been employed. • CFD modeling was employed to assess dead zones and flow maldistribution.