Library Subscription: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

IMPROVING FAST REFILL EFFICIENCY OF COMPRESSED NATURAL GAS BY PRE-CHILLING

Get access (open in a dialog) DOI: 10.1615/IHTC16.ctm.022853
pages 3707-3714

Abstract

The fast refill process rapidly fuels natural gas vehicles by forcing compressed natural gas (CNG) into the vehicle's CNG fuel tank. The conventional fast refill produces a significant amount of heat inside the fuel tank due to the recompression work applied to the natural gas. This heat lowers the gas density and thereby limits the mass of gas that can be carried and reduces the vehicle's driving range. To refill more natural gas, a method referred to as the pre-chilling method is proposed and numerically simulated. A heatsink installed inside the tank is cooled down below ambient temperature by the vehicle's onboard air conditioning system. This pre-chilled heatsink absorbs the recompression heat during the refill process, which helps increase the refilled mass. Two-dimensional axisymmetric CFD (computational fluid dynamics) simulation of unsteady, compressible, turbulent flow is conducted for a type-III cylinder being fast-filled with the pre-chilling thermal management. Dynamic average temperature and mass curves as well as transient temperature distribution in the cylinder are presented. Maximum improvement of fill efficiency achieved through pre-chilling is 6.6% showing the effectiveness of this method.