Session: 17-01-01: Research Posters

Paper Number: 144417

144417 - Lh2 Tanks in Fire Incidents - the Cryogenic High Temperature Thermal Vacuum Chamber Enables In-Depth Insights 

In the course of decarbonizing the energy industry, cryogenic energy carriers are seen as having great potential. This is because they allow significantly higher volumetric energy densities to be achieved than when these energy carriers are stored at typical temperatures on Earth. This is important for numerous energy-intensive applications, such as those found in all transport sectors. Important cryogenic energy carriers include liquefied hydrogen (LH2) and liquefied natural gas (LNG).

The challenge is to keep the energy carrier cold for a long time. This is achieved by the implementation of thermal super-insulations (TSI) systems based on multilayer insulations (MLI), microspheres, perlites, and vacuum for instance, and which have proven to be effective in several cryogenic applications. However, due to the short period of use, the low number of documented incidents, and the still few investigations carried out in the field, the exploitation of such systems in the transport sector still suffers from insufficient knowledge about the course and consequences of incidents. Accidents involving collisions, fires, and their combination are quite common in the transportation sector and may generate extraordinary loads on the tank and its insulation system, eventually leading to tank failure.

The present study focuses on the behavior of TSI in tanks when it is exposed to an external heat source which is representative of a hydrocarbon fire. This may cause an increase of the heat flow into a tank by several orders of magnitude to normal design conditions, based on thermodynamics and damage to the thermal insulation system. Finally, such an event could lead to a rapid release of flammable gasses by the safety valves, or in the worst case to a Boiling Liquide Expanding Vapour Explosion (BLEVE).

To study the relevant effects on this objective a test rig was developed that allows repeatable testing of TSI at industrial conditions in a fire scenario, the quantitative measurement of the heat flow by the double-walled system and to analyze the TSI sample before and after the test. This test rig takes into account the typical double-walled design of tanks for cryogenic fluids with vacuum and an additional insulating material in the interspace.

In the paper, a new test concept will be presented that was designed and manufactured. This concept is based on the recent findings from diverse tested TSIs that will be presented to justify the design specifications. All in all, there are strong differences between the different TSI systems. Several safety concerns and research gaps come with layered insulations which are typically used in the transport sector and which will be the focus of this new test chamber named Cryogenic High Temperature Thermal Vacuum Chamber (CHTTVC). This concept enables the test of larger TSI samples at industrial conditions, and the consideration of cryogenic conditions, which are relevant for the investigation of various phenomena. These results are relevant for the evaluation of incidents with storages for cryogenic fluids and can thus contribute to the improvement of TSI and the development of emergency measures for the protection of persons and infrastructures.

Presenting Author: Frank Otremba Bundesanstalt für Materialforschung und -prüfung (BAM)

Presenting Author Biography: Frank Otremba is the Head of the BAM division “Tanks for Dangerous Goods and Accidental Mechanics” in Berlin and honorary professor at the technical university of Brandenburg. He graduated as mechanical engineer (Dipl.-Ing.) and got his Ph.D. from University of Rostock in the field of numerical methods and fracture mechanics in 1991.

Authors:

Robert Eberwein Bundesanstalt für Materialforschung und -prüfung (BAM)
Giordano Emrys Scarponi Alma Mater Studiorum - Università di Bologna
Valerio Cozzani Alma Mater Studiorum - Università di Bologna
Frank Otremba Bundesanstalt für Materialforschung und -prüfung (BAM)