Development of a Climate and Altitude Simulation Test Bench for Handheld Power Tools 2018-32-0033
For evaluating the overall suitability of using innovative biofuels in handheld power tools such as chainsaws, trimmers and blowers, under any typical operating condition worldwide, a climate and altitude conditioning test bench was developed at the Institute of Energy Efficient Mobility (IEEM) of Karlsruhe University of Applied Sciences. The 6 m³ hermetically sealed and thermally insulated test chamber is large enough to fit the entire power tool. A two-stage refrigeration system with intake air drying and resistance heating allows for realistic temperature conditions to be set in the test chamber, ranging from arctic cold to tropical heat (-20 to 45 °C). Altitudes up to 3,000 m above sea level can be simulated using a throttle valve at the inlet of the chamber and a pressure-controlled rotary piston blower positioned downstream the test chamber outlet. The air-cooled engines to be tested are fully exposed to the ambient conditions inside the test chamber, able to aspirate the conditioned combustion air freely and release both exhaust gas and waste heat into the chamber environment. In order to control the power tools when the chamber is closed, an adaptive remote control system was specially developed. It enables automatic engine start by cable pull (e.g. for cold start testing), engaging the choke valve as well as operating the throttle lever automatically.
This paper discusses the development process, the design, the operating limits as well as the transient and stationary operating behavior of the climate and altitude simulation test bench.
Artur Martel, Fino Scholl, Dennis Weierter, Maurice Kettner
Karlsruhe University of Applied Sciences
SAE/JSAE Small Engine Technology Conference