Siemens Energy’s Brian Grosso Unveils Compressor Testing Results with High Impeller Tip Speed

Brian Grosso of Siemens Energy’s Advanced Compression Systems continued the conversation surrounding its new hydrogen compressor demonstration, which passed performance and mechanical testing up to high-speed operation in a closed-loop facility. Grosso contributed a technical analysis of how Siemens Energy achieved high impeller tip speeds and its benefits for hydrogen compression applications.

He also disclosed some performance and rotordynamics testing results, which displayed multiple levels of API compliance across power tolerance, allowable vibration, and performance on the operating map. Lastly, Grosso explains the purpose of gaseous helium in compressor mechanical testing and why pure hydrogen testing may be required for future generations of high-speed machines.

TURBO: What is the role of gaseous helium in this closed-loop hydrogen compression system?

Grosso: Helium is the closest inert gas in mole weight to hydrogen, and it’s typically used in compressor mechanical testing. As the closest inert gas, we can test it at a high fraction of the compressor speed to ensure safety before we tested with hydrogen. At some point, when you start adding enough head and more stages to the machine, testing with helium would get too hot at full speeds. To fully test the capabilities of these machines in the future, it’s anticipated that you’ll need to test using hydrogen gas.

TURBO: Can you speak on the performance and rotordynamics testing results?

Grosso: We met stricter than API 617 performance guarantees in terms of the power tolerance. We did work to analyze the effect of the semi-open impeller shroud gap on performance throughout the operating map. The mechanical test results were also very positive: The API allowable vibration limit decreases with speed, but we were able to meet the allowable vibration limit during these tests – even up to approximately 28,000 rpm.