In the future, hydrogen technology will also be used on rails. In the future, regional trains will be equipped with fuel cells that convert oxygen and hydrogen into electrical energy.
In its “Heat2Comfort” project funded by the BMWI, the Fraunhofer Institute for Manufacturing Technology and Applied Materials Research IFAM in Dresden is making its contribution to this type of emission-free and low-noise mode of transport.
Together with its partners, Hörmann Vehicle Engineering GmbH, Wärmetauscher Sachsen GmbH and the Institut für Luft- und Kältetechnik Gemeinnützige Gesellschaft mbH, the institute is working on a new approach to using waste heat for vehicle air conditioning. The partners are also supported by DB Systemtechnik GmbH, DB RegioNetz Verkehrs GmbH and Energieanlagenbau GmbH Westenfeld.
The central idea of the approach is an effective utilization of the fuel cell waste heat for the temperature control of the vehicle interior. This is intended to increase the minimum range of fuel cell multiple units by 20%. At the same time, the comfort of travelers is to be increased from both a thermal and acoustic point of view.
The aim is to cover both heating and cooling with the waste heat from the fuel cell. This means that the waste heat can even be used for indoor air conditioning during summer operation by supplying an absorption heat pump with waste heat from the fuel cell to generate air conditioning.
As a result, the electricity from the fuel cell can be used in a concentrated manner for propulsion and does not have to be used for air conditioning. In contrast, today’s vehicles require up to 25% of the total energy requirement for air conditioning in the passenger compartment and driver’s cab. The efficient use of the existing fuel cell waste heat is a major influencing factor for increasing the range.
In addition to its materials science expertise, the Energy and Thermal Management business area at Fraunhofer IFAM Dresden also contributes its know-how on the thermal and fluidic development of components to the “Heat2Comfort” project. In addition, there is extensive experience in mathematical modeling and experimental validation of flow, heat and material transport processes.
Specifically, the researchers within the project deal with the coupling of the heat source, i.e. the fuel cell, with the various uses of heat in the form of absorption chillers and space heating. This is done via PCM memory, in which fiber structures are used to adapt the memory capacity.
In addition, the thermal activation of interior surfaces and other built-in components such as table and seat constructions is considered.
The many years of expertise at Fraunhofer IFAM Dresden in the field of cellular metallic materials also benefit when optimizing the temperature distribution on the surfaces. For example, findings from the recently completed “Hybrid-FHKL” project, in which hybrid heating and cooling surfaces with room air conditioning for building technology were developed and investigated, are used. The use of cellular metals to generate uniform surface temperatures is a central question that is also relevant in “Heat2Comfort”.
At Fraunhofer IFAM Dresden, simulations of energy flows, storage behavior and the design of cellular metallic materials for thermal component activation are also carried out.