EKOK – Comfort- and energy consumption optimized indoor air-conditioning systems for rail vehicles
Starting point / Motivation
The requirements in terms of comfort are enormous in rail vehicles, especially for passenger transport on long-haul routes: noticeable temperature fluctuations or permanent air currents are normally not tolerated by the passengers. However, the cooling systems providing this function consume a lot of energy. Dogmas induced by norms, such as the maximum preheating time of vehicle in the parked and cooled state lead to an oversizing of systems in comparison to what would be necessary for the regular operation. Thus, has a significant impact on the loss of energy efficiency.
Contents and goals
The aim of this project is to maximize the traveller's comfort in rail vehicles while minimizing the cooling relevant energy consumption by the use of innovative technology approaches aside from standardized dogmas.
By means of computer-aided flow simulation (CFD), the possibilities and limits of new technology approaches in heating and cooling were investigated, taking into account the increasing comfort requirements of the modern traveler. The investigation of the influence of different parameters on the comfort perception included the following points:
- Determination of the best possible "Control levers"
- Analysis of the relevant technologies as well as the current procedures and parameterization of cooling- and heating systems
- Comparison of the different systems by means of a CFD-Simulation and the calculation of the resulting comfort-indicators
- Comparison of the conceptual approaches regarding energy consumption and comfort
- Qualitative considerations in view of regulation and the thereby associated application conditions of the respective system
Results and Conclusions
The simulation studies carried out have shown that air-conditioning systems with floor heating systems significantly increase comfort and, at the same time, also reduce energy consumption. Heating solutions embedded directly in the floor, in the walls or also in the windows (in the sense of "active heat insulation") avoid low radiation temperatures, which otherwise have a very negative effect on comfort.
Due to the almost loss-free conversion of electrical energy into thermal energy, the energy consumption and thus also the operating costs can be reduced with surface heating systems. The results of these simulations can be used as a decision support for further development of innovative concepts for series production.
Dr. Manfred Hofer, Molinari Rail Austria GmbH
DI Gabriel Haller, RTA Rail Tec Arsenal Fahrzeugversuchsanlage GmbH
Molinari Rail Austria GmbH
Dr. Manfred Hofer
Tel.: +43 (5242) 71400-30