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A filling process of the pressure bottle used for the air storage was investigated by numerical simulations. During the filling process, the temperature was rising up to maximal value and after that started to decline. The good match was found between experimental and numerical results. In order to reproduce the experimental conditions, the process of the filling bottle was controlled by the pressure which varied in time. This filling strategy influenced furthermore the mass flow rate and the air flow velocity. Because of the geometrical symmetry, the simulation was calculated as an axisymmetric problem.
Transport safety depends in great extent of what happens to the cargo once the carrying vehicle derails or rollovers. The exposure of tanks to direct fire is a condition that potentially involves catastrophic consequences. Studying the behavior of the contained fluid under these drastic circumstances, is critical to develop methods and techniques to mitigate the serious consequences of many mishaps. In this paper, the experimental potentials of a Particle Image Velocimetry data acquisition system are described, for providing experimental data that could be used to calibrate mathematical models. As an example of the situations that need to be modelled, an experiment is described concerning the effect of the boundary conditions and protecting devices, on the rate of variation of pressure and temperature of the fluid in a tank exposed to a direct fire. In this regard, the results emphasize the importance of equipping the vessels with both thermal insulation and safety valves.
Small and large-scale tests have been carried out Pressure vessel – to improve numerical modelling Different types of fire must be distinguished Modelling of vessels were discussed Test configuration has been developed to see what happens in the vessel First results encourage us to continue the Research Thermohydraulics needs further work (boundary layers).
There was a need to validate the longitudinal performance required for the cargo securement, as current standards exhibit differences. A model has been proposed in this paper, to simulate the effect of a shifting cargo on the braking efficiency of the vehicle. Results suggest that the braking efficiency can be greater in the case of a shifting cargo, as a result of the uncoupling of the cargo-vehicle systems, implying that similar braking forces are exerted on a reduced mass. The shifting of the cargo can occur as a result of the vibration of the vehicle, that leads to having a diminished friction force to prevent the shifting of the cargo.
The safety of any transport system depends on a multitude of conditions, parameters and circumstances. In this regard, the interaction of the carried Cargo with the carrying vehicle represents a factor influencing the overall safety of any transport. The effects of cargo on the vehicle have to do with the vibration or shifting of the cargo, affecting the lateral stability of the vehicles and the braking performance.
Such interaction has been associated to road crashes and maritime vehicles capsizing. Simulation of cargo-vehicle interaction thus represents an interesting Topic when a reduction in transport accidents is pursued. In this paper, the fundamentals principles for simulating the interaction of the liquid cargo and the carrying vehicle, is presented. In the case of a road transportation, the proposed simplified Simulation methodologies, show good agreement with a full-scale test.
Biofuels, particularly biodiesel, have gained significant attention as an alternative to traditional fossil fuels in recent years. Unlike diesel, which contains hundreds of compounds, biodiesel only contains a few compounds in the C16-C18 carbon chain. However, the use of biodiesel in automobile and transportation applications can result in problems of degradation or even damage in materials. Among the commonly used polymer materials, fluorocarbon (FKM) shows excellent performance and high stability and compatibility towards oil, diesel, ethanol, and other chemicals. FKM is a family of fluorocarbon-based fluoroelastomer materials, which provide excellent high-temperature and chemical stability compared to other elastomers. As a result, FKM is widely used in chemical processes such as petroleum refining, where it is used for sealings, pumps, and other components.
Mechanical stress often accelerates the failure of polymer materials. The aim of this research is to study the interaction between the sealing material FKM and biofuels B10 (heating oil with 10% biodiesel). The mechanical stress test was carried out in a special apparatus. Both mechanical and non-mechanical stress tests were conducted on specimens at 20, 40, and 70 °C for 28 days to document changes in mass, volume, and tensile properties. Both increasing temperature and mechanical stress have a significant effect on the tensile strength of the FKM polymer when exposed to B10. The combination of increasing temperature and mechanical stress induced rupture within 2 h. It was also established that FKM polymer with pre-exposure in B10 survived longer during mechanical stress compared to specimens exposed only to air. With the support of infrared (IR) spectroscopy, we were able to confirm the penetration of B10 into the FKM polymer.
The importance of tanks for storing cryogenic fluids in the energy industry is increasing because of ongoing political conflicts and the implementation of more environmentally friendly energy sources. Key representatives for the application of cryogenic tanks are natural gas in the form of Liquefied Natural Gas (LNG) and hydrogen, e. g. in the form of Liquefied Hydrogen (LH2), for which significantly higher transport capacities can be achieved with the same transport volume using cryogenic storages than with storages based solely on overpressure.
What applies to all cryogenic transported fluids in common is their condition that must be maintained. Hence heat flows into the preserved fluid must be minimized. Thermal super Insulations (TSI) based on e. g. multilayer insulations (MLI), perlites, and vacuum are utilized for this purpose and have already proven themselves in similar applications. However, for the use of tanks for cryogenic fluids in the transport sector, there is insufficient knowledge regarding the course and consequences of incidents, which is due to the still short period of use and the few documented incidents, hence few investigations carried out in this field. Typical scenarios in the transport sector represent car accidents with collisions, fires, and their combination, which are associated with extraordinary loads on the tank.
The focus of this study is to investigate the behavior of TSI as a result of their thermal exposure to a heat source representing a fire. It is worth mentioning that this could lead to an increase of the heat flux into a tank by several orders of magnitude, and to permanent damage of the TSI, ultimately rapid release of flammable gas as well as a Boiling Liquide Expanding Vapour Explosion (BLEVE). For this purpose, a high temperature thermal vacuum chamber (HTTVC) has been developed that allows thermal loading of MLI or perlites in a vacuum and simultaneous measurement of heat flow through this TSI. The HTTVC is designed to represent realistic insulation conditions and to withstand thermal loads from typical design fires.
The HTTVC was applied to investigate TSI based on MLI and vacuum. It is shown that the thermal stress caused permanent damage to the TSI, with shrinkage, phase change, pyrolysis, and condensation being significant damage mechanisms. The results are relevant for the evaluation of accident scenarios and can thus contribute to the improvement of TSI and the development of emergency measures for the protection of persons and infrastructures.
Liquefied Hydrogen (LH2) or Liquefied Natural Gas (LNG)
establish themselves as important energy carriers in the transport
sector. Its storage requires tanks with Thermal Super Insulations
(TSI) to keep the transported fluid cold. TSI has proven itself in
various applications over a long time, but not in the land
transport sector, where accidents involving collisions, fires, and
their combination are to be expected. The focus of this study is
to investigate the behavior of different types of TSI when
exposed to a heat source that represents a fire. Therefore, a High-
Temperature Thermal Vacuum Chamber (HTTVC) was used that
allows the thermal loading of thermal insulation material in a
vacuum and measuring the heat flow through the TSI in parallel.
Within this study, 5 samples were tested regarding 3 different
types of MLI, rock wool, and perlites. The thermal exposure
caused different effects on the samples. In practice, this can be
connected to the rapid release of flammable gases as well as a
Boiling Liquid Expanding Vapour Explosion (BLEVE). These
results are relevant for the evaluation of accident scenarios, the
improvement of TSI, and the development of emergency
measures.
The interest in hydrogen-based green energy is increasing worldwide, and the same is true for hydrogen-powered vehicles. Among the possible solutions to store hydrogen in such vehicles, cryogenic tanks equipped with multi-layer insulation (MLI) are the most promising to increase the amount of energy stored per unit volume. However, MLI is affected by severe deterioration when exposed to an external source of heat such as a fire following a car accident, leaving the tank unprotected and leading to failure in a relatively short time. In this work, a one-dimensional model to evaluate MLI thermal degradation when a liquid hydrogen tank is exposed to fire is presented. The relevance of taking MLI degradation into account when simulating the pressure increase due to external fire exposure is here demonstrated through the analysis of several case studies. The results show that MLI systems performance depletes within a few minutes of exposure to hydrocarbon poolfire.