Garrett Motion is advancing the design of its fuel cell compressor technology with a new-generation device that is more than 40 percent smaller than the previous model for the same fuel cell stack output.
The company uses similar technology as its electric turbochargers for combustion engines to push moist air through fuel cell membranes. Some fuel cells employ reciprocating compressors that give those vehicles the sound of a quietly idling lawnmower.
Garrett says that its smooth turbine e-compressors are even quieter than before, while the extra capacity comes from spinning the turbine faster than 150,000 rpm. That’s a 50 percent increase in speed over the first-generation e-compressor.
Impressively, the price tag of this new smaller unit is also smaller: just one-third the cost of the previous e-compressor. Additionally, an optional second compressor, or turbo expander, boosts electrical efficiency so that Garrett’s turbine e-compressor uses 20 percent less electricity than reciprocating models.
The e-compressor can spin at such elevated speeds reliably thanks to its use of airfoil bearings that eliminate the risk of degradation due to oil contamination. Garrett claims best-in-class durability with more than 1 million start-and-stop cycles over 25,000 hours of life. The air bearing is also quieter and provides better shock absorption due absence of physical contact between the motor housing and the rotating turbine assembly.