Numerical investigation of the vortex tube performance in novel precooling methods in the hydrogen fueling station

In the present study, the potential of integrating a Ranque-Hilsch vortex tube (RHVT) in the precooling process for refueling high-pressure hydrogen vehicles in hydrogen refueling stations is investigated. In this regard, two novel precooling processes integrating a vortex tube are proposed to significantly reduce the capital expenditure and operating costs in hydrogen fueling stations. Then a numerical study of the RHVT performance is carried out for a high-pressure hydrogen flow to validate the feasibility of the proposed processes. Obtained results from the numerical simulation show that the energy separation effect also exists in the RHVT with hydrogen flow at the pressure level of tens of megapascals. Moreover, it is found that the energy separation performance of the RHVT improves as the pressure ratio increases. In other words, the temperature drop of the cold exit of RHVT decreases as the pressure ratio decreases in the refueling process, which just matches the slowing-down temperature rise during the cylinder charge. Based on the obtained results, it is concluded that the integration of a RHVT into the precooling process has potential in the hydrogen fueling station. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study investigates the potential of integrating a Ranque-Hilsch vortex tube (RHVT) in the precooling process for refueling high-pressure hydrogen vehicles at hydrogen refueling stations. Two novel precooling processes are proposed to reduce costs, and a numerical study shows that the RHVT exhibits energy separation effects with high-pressure hydrogen flow, with improved performance at higher pressure ratios. The integration of a RHVT into the precooling process is concluded to have potential in hydrogen fueling stations.