Elliott Group has developed a new, reconfigurable compressor configuration for hydrogen applications.
The Flex-Op® compressor configuration enhances reliability and accessibility to the rotating components, and leverages Elliott’s over 70 years of proven hydrogen compression experience.
“Hydrogen compression requires a large number of compression stages to achieve a reasonable head for a very light gas,” said Dr. Klaus Brun, Elliott’s Director of Research and Development. “With the Flex-Op arrangement of three to four casings, up to 40 impeller stages can fit into a footprint that traditionally only fit up to 10 stages. This shrinks the linear footprint of the compressor section from 40 feet or more to about 10 feet, and offers up to four times the compression capability within the approximate linear footprint of one compressor.”
Individual compressors can be run in series or parallel, or both, in the Flex-Op configuration. Three to four centrifugal compressors are stacked around a single multi-pinion gearbox to accomplish this. Each rotor is connected to its own pinion through a flexible shaft attached to the central gear, allowing for individual optimization of rotor speeds for maximum aerodynamic efficiency. Elliott’s barrel casing configuration, along with the single multi-pinion gearbox, enables the assembly to be powered by either a variable frequency drive (VFD) or a motor in conjunction with a variable speed drive (VSD).
Numerous advantages exist between the Flex-Op setup and reciprocating or high-speed centrifugal compressors. It is compact and simple to maintain and repair because it utilizes ordinary Elliott compressors and impellers. Individual compressors can be engaged or disengaged, series or parallel operation can be selected, and each compressor can run at a different speed. Most crucially, for pure hydrogen compression, the process gas is oil-free. Finally, the Flex-Op concept is not confined to hydrogen applications but also works well for energy storage, process compression, and refining.
