A focus on temperature management

The drive system of a rail automobile is the most important power shopper in operation, adopted by the programs for temperature administration of the passenger compartment and the drive system—no matter the kind of prepare propulsion. Batteries or gas cells should be maintained at an optimum working temperature in electrically powered trains with out power provide by way of overhead traces or third rails.

Many rail operators are contemplating such trains for the almost 40% of non-electrified tracks in Germany. The general power consumption in these trains considerably impacts vary and potential working occasions.

Probably the most appropriate technique for temperature administration of the drive system, inside, and any onboard power storage will depend on the drive idea, local weather, and working situations.

The grasp thesis of Marcos Escamilla Sánchez on the potential of built-in thermal administration, which obtained the Glorious Thesis 2024 award at Fraunhofer IWU, concludes that the DB class 490, used within the S-Bahn (suburban prepare) operation of Hamburg, has such an environment friendly thermal administration system, due to its warmth pump and waste warmth restoration from traction and auxiliary operations, that steady growth seems most cheap.

This mannequin is a purely electrical prepare with out a further battery. The system’s effectivity (Coefficient of Efficiency) is excessive all year long due to the energy-efficient air-con and heating.

Sánchez at the moment works as a programs engineer on the rail automobile producer Alstom. Along with the local weather know-how specialist and tools supplier for battery-powered commercial vehiclesWölfle GmbH, he investigated underneath which working situations an built-in thermal administration system may provide effectivity benefits.

The thought is to design a complete system that connects the drive system and, the place current, the batteries and power electronics in a water circuit coupled with a heat pump or chilled water air-con system.

Such an strategy ought to cowl all temperature situations: the passenger compartment and battery must be heated in winter and cooled in summer season; whereas the waste heat from the drive will be utilized in winter, it should be dissipated from the system in summer season.

The outcome: a calming water air-con system offers little effectivity acquire on common in Hamburg; nonetheless, it may reveal its benefits in icy areas—the place heating is usually required all year long, whereas cooling is comparatively uncommon.

Operators will see one of the best coefficient of efficiency in a automobile operation characterised by frequent acceleration and braking, quick distances, and frequent stops, which aligns significantly effectively with the working profiles of S-Bahn and U-Bahn (subway) programs. An built-in thermal administration system may additionally save weight and require fewer HVAC (Heating, Air flow, Air Conditioning) parts.

Sánchez is assured that the influence of an built-in thermal management system on the energy balance and value of battery-electric prepare programs or trains with hydrogen gas cell propulsion can be substantial, as in such programs, the energy storage requires almost fixed cooling or heating.

Offered by Fraunhofer Institute for Machine Instruments and Forming Know-how IWU