Působení vnějšího zdroje tepla na tlakovou láhev

Abstract

This bachelor’s thesis investigates the effects of an external heat source on a pressure cylinder designed for gaseous hydrogen storage. Prior to the theoretical part of the thesis, the investigated issue is set within the broader context of hydrogen technology safety and the risks associated with the thermal loading of pressure vessels. The theoretical part summarizes the fundamental physical and chemical properties of hydrogen, provides an overview of the design types of pressure vessels used for its storage, and describes the basic mechanisms of heat transfer under thermal loading. The practical part focuses on the development and validation of a numerical model for estimating the heating of the vessel wall, the heating of the internal medium, pressure development, and changes in material properties at elevated temperatures. The model is formulated as a two-dimensional transient heat conduction problem, complemented by a gas energy balance, composite matrix decomposition, and a simplified strength criterion. The model was validated on two cases. The first case was an open type I steel cylinder, where the simulation accurately reproduced the experimentally measured thermal response. The second case was a type IV composite vessel corresponding to the tank of a first-generation Toyota Mirai vehicle, in which temperature profiles, hydrogen pressure response, and composite matrix degradation were monitored. A comparison of numerical results with experimental measurements demonstrated that the proposed model is applicable for predicting the fundamental behavior of a pressure vessel under local thermal loading, while also revealing its limitations, particularly in the later stages of the process following the loss of vessel integrity.