CryoEvap: An open-source software to simulate the evaporation of cryogenic liquids in vertically orientated storage tanks

The paper presents a new software tool, CryoEvap , based on a novel and validated modelling approach that simulates the isobaric evaporation of cryogenic liquids in storage tanks. CryoEvap provides time-dependent liquid volume, boil-off gas rates, boil-off gas temperature, average vapour temperature, vapour temperature profiles, different heat ingresses and estimates of transient time relevant to industrial applications in cryogenic energy storage. The software has been implemented in Python under an object-oriented programming paradigm. CryoEvap is designed to aid research in novel applications such as renewable energy storage and the optimal integration of the storage tanks into process simulators. In this paper we provide new research insights into the behaviour of cryogens when stored in two industry-relevant scenarios of large and medium scale storage. The results indicate that the transient period varies drastically between different sized storage tanks and that the inclusion of the vapour thermal expansion is an essential pre-requisite for good estimates of the boil-off gas rates.