Commercial vehicles constantly require power – in driving mode as well as during breaks. At the IAA in Hanover (hall 16, stand B02), Eberspaecher is presenting a fuel-cell APU (auxiliary power unit) that converts diesel very efficiently to electricity and thereby supplies all on-board consumer components. The system – entirely independent from the engine – revolutionizes energy management in the truck: for electricity generation the load can be taken off the generator and consumption and emissions decrease. In future generations of trucks, components still driven mechanically today could thus be powered electrically at considerably less expense.
Whether for the air conditioning system or the refrigerator – the numerous consumers of electricity on board of a commercial vehicle constantly require power. During the journey this need has so far been met via the generator. In stationary periods, a diesel auxiliary power unit or, in the worst case, the idling engine takes over the supply of on-board electricity and air-conditioning: the so-called diesel-engine APU usually drives the air-conditioning compressor mechanically – via a belt – and produces electricity. The fuel-cell APU presented by the German automotive supplier in Hanover can do significantly more: “Not only does our system solve the energy problem during stationary periods – rather, we’re pursuing a new, holistic approach to on-board power supply in the truck that, beside the environmental balance, also decisively enhances operating efficiency”, explains Dr. Klaus Beetz, COO Eberspaecher Climate Control Systems.
Same output – 50 percent less consumption
The innovative fuel-cell APU generates electrical power – without mechanical power losses – from the diesel in the truck tank quietly, in an energy-saving way and virtually emissions-free. Nitrogen oxide, carbon monoxide and soot particulate emissions are 90 percent less compared with a diesel-engine APU. Thanks to the control electronics, only as much electricity is produced as is actually required. The maximum output is 3 kW, the possible efficiency is up to 40 percent. The system operates so effectively that it can be used as a supplier of energy not only during stationary periods but on a permanent basis. When the truck starts for driving the fuel-cell system starts as well, supplying all the consumers of electricity. This relieves the generator, which would otherwise require approximately double the amount of fuel to provide the electrical power as the diesel fuel-cell system. The longer the fuel-cell system runs and the more power is called off, the more powerfully it enhances the overall efficiency and cost effectiveness of the vehicle. “Reducing consumption is a key challenge in the transport sector – with our fuel-cell solution, future generations of trucks can achieve potential savings in electricity supply”, comments Dr. Beetz.
Operating principle based on core competencies of the Eberspaecher Group
The basis of the Eberspaecher APU is a high-temperature fuel cell that can generate electricity from fuel gas of fossil origin. This fuel gas is produced in a so-called reformer: here, diesel is first mixed with air; afterwards the mixture flows through a catalytic converter. This process generates fuel gas containing hydrogen and carbon monoxide. The technology required for this process is based on the core competencies of the Eberspaecher Group: “The mixture formation is based on our know-how in the area of fuel-operated pre-heaters, whereas in catalysis our exhaust technology skills are brought to bear”, underlines Dr. Beetz.
Fuel-cell system paves the way for further electrification
The electrification of commercial vehicles is an important aspect in further fuel and CO2 reduction in the transport sector. The diesel fuel-cell APU is an important part in this future strategy. Many energy-intensive consumers, that were previously coupled with the drive engine, such as the cooling water- and hydraulic pump or the compressed-air system, could in future be operated considerably more efficiently by electric means – using electricity from the mobile fuel-cell system. Even the air-conditioning compressor, today coupled with the engine, plus an additional auxiliary cooling system could be replaced by a single electrical AC system for driving and stationary operation. One major advantage: the output of the drive engine would then almost exclusively take care of propulsion, which reduces consumption further. Thanks to the switch from mechanically to electrically driven components, the weight distribution in the truck could also be revolutionized. And, because the battery is constantly in an ideal charging state during fuel-cell operation, the batteries lifetime lasts longer and the truck cuts out more rarely.
“At the present time we’ve not yet reached the end of development”, sums up Dr. Beetz. “But currently we’re pressing ahead with the systems development together with a well-known commercial vehicle manufacturer. Before this year is over we’ll be carrying out extensive practical testing and are planning to launch the fuel-cell APU initially on the US market at the end of 2017.”
Eberspaecher sets standards
As an innovation partner of the automotive industry, Eberspaecher traditionally develops solutions that set new standards: in 2013, the company launched the Hydronic 2 Comfort, the fastest pre-heater in the world. ActiveSound, a technology based on antisound, enabling the exhaust gas sound to be configured as required, has been in production since 2011. A further example is the highly complex exhaust-gas aftertreatment systems for commercial vehicles complying with emission standard Euro 6. The new fuel-cell APU now continues this series of innovative solutions for the more efficient mobility of the future.
