Sander M.,KIT ITEP |
Brighenti F.,KIT ITEP |
Gehring R.,KIT ITEP |
Jordan T.,KIT IKET |
And 6 more authors.
International Journal of Hydrogen Energy | Year: 2014
A new multi-functionality hybrid energy storage concept, LIQHYSMES, has been recently proposed. It combines the use of LIQuid HYdrogen (LH2) as the bulk energy carrier with much faster and efficient superconducting magnetic energy storage (SMES). The LIQHYSMES Storage Unit LSU integrates liquefaction and storage of H2 as well as the LH2-cooled SMES: A process for the intermediate storage of H2 in liquefied form is proposed, and alternative SMES designs are compared. The basic operational principle is simulated for a simple model case with two large LIQHYSMES storage plants supporting the transfer of renewable energy from one region of strong supply to a second one with a widely negative imbalance between supply and load. Losses of all plant components are analysed in terms of their relevance for the overall efficiency, and some cost issues are briefly addressed. A small first experimental demonstration is now underway and also briefly introduced. Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Spengler C.,GRS Society for plants and Reactor Safety |
Foit J.,KIT IKET |
Fargette A.,AREVA |
Agethen K.,Ruhr University Bochum |
Cranga M.,Institute for Radiological Protection and Nuclear Safety
Annals of Nuclear Energy | Year: 2014
In the course of a severe accident in a light water reactor, the interactions of corium with the concrete structures of the reactor cavity (Molten Corium-Concrete Interactions or MCCI) may have a significant impact on the long-term integrity of the containment. The 2D behaviour of the melt pool contained in the reactor cavity under dry or top flooding conditions is considered as one of the key phenomena. The "scaling" issue is usually resolved by - in a first step - identifying the impact of physical mechanisms on the process and - in a second step - evaluating these mechanisms at scaled conditions regarding time and length. The conditions for the MCCI change with time due to the evolution of the melt's state defined by e.g., its composition, temperature and solid fraction, and due to the change of cavity contour and the decreasing decay heat. Here, simplified models are investigated with the objective to infer from laboratory-scale experiments how basic and important parameters like the temperature of the melt and the erosion depth evolve with time if transposed to reactor scale. Due to the simplifications in the models under consideration, the MCCI is analysed assuming "ideal" boundary conditions as e.g., an evolution of a cavity contour with time while retaining its geometrical shape (sphere, cylinder, etc.). Based on these idealised assumptions, generic trends for physical parameters like melt temperature, heat flux at the pool boundary surface, concrete fraction in the melt, viscosity, etc. can be deduced. Simple scaling methods are introduced and checked for consistency by comparison calculations with the MCCI MEDICIS module of the ASTEC integral code. Finally they are applied to a scaling problem under ideal and simplified initial and boundary conditions and the resulting generic trends of the physical parameters are evaluated at reactor scale. Such methods are very useful to better understand the MCCI phenomenology although more detailed MCCI codes are indispensable to simulate more complex accident sequences or to take into account complex boundary conditions. © 2014 Elsevier Ltd. All rights reserved.