An auxiliary power unit (APU) is a small, self-contained power source that is used in land and rail vehicles as well as in general aviation or maritime applications. These units provide an independent power supply that allows the main engine to remain switched off while electrical devices continue to operate. Based on the SP-180 SRE-hybrid Wankel engine, Sky Power International offers the SP-180 SRE APU demonstrator mobile APU test and evaluation system.
The system runs on gasoline. A 48V DC power supply is required to operate the demonstrator. Exhaust and silencer, engine control unit (ECU), starter and alternator (12KW constant), EFI, fuel pump, an electrical system consisting of power supply and starter control, a thermal system for oil, as well as a cooling circuit including pumps and a heat exchanger, are installed as standard in the SP-180 SRE APU demonstrator.
“The compact design makes the entire system ideal for mobile use,” explains Karsten Schudt, managing director of Sky Power International. With the installed SP-180 SRE hybrid Wankel engine, the APU demonstrator works very efficiently. Thanks to the compact design of the engine, the test and evaluation system is very space-saving, lightweight and extremely smooth-running. Furthermore, Wankel engines can also reach higher speeds with low vibrations.
“Thanks to its very compact and simple design, low vibrations, high speeds and consistent power output, the Wankel motor offers some decisive advantages over traditional reciprocating piston engines. These characteristics make it particularly attractive for applications where space, weight and power play a major role,” continues Schudt.
In addition, the Wankel engine offers further significant advantages in APU applications. By using the APU, the main engine can be switched off when idling, which can significantly reduce fuel consumption. Switching off the main engine also leads to a considerable reduction in exhaust emissions. By using an APU, wear can be reduced, which extends the service life of the main engine and reduces maintenance costs.
“Overall, Auxiliary Power Units offer a wide range of benefits for land vehicles and help to reduce fuel consumption, protect the environment and increase comfort for users. With advancing technology, such as that of the Wankel engine, APUs will become even more efficient and environmentally friendly,” says Schudt.