Development of a Centrifugal Hydrogen Pipeline Gas Compressor

Written by Francis A. Di Bella, PE and Dr. Colin Osborne of Concepts NREC - Tuesday, January 12 2010

In order to quantify the susceptibility of the aluminum and titanium alloys to hydrogen embrittlement, Texas A&M has fabricated a special test fixture identified as a Small Hole Punch assembly to be used with a standard Instron tensile test machine. The test apparatus will puncture a hole into a test specimen that measures 3 mm in diameter and 0.5 mm thick. The purpose of these tests is to determine the relative effects of hydrogen exposure on the metal matrix, and thus, determine if the metal strength has been compromised.

The complete hydrogen pipeline compressor package that integrates all of these major components is shown in Figure 5. The complete modular package, as shown, is 26 ft long x 10 ft tall x 6 ft wide (at the base) x 8 ft. wide at the control panel, approximately ½ the footprint of a piston-type, hydrogen compressor. The packaged module can be transported to the installation site as a pre-assembled package with a minimum of final alignment, water piping, and electrical power connections, instrumentation, and controls start-up.

Preliminary design details of the completed pipeline compressor module include:

• Compressor design conditions confirmed by project collaborators
• P_inlet= 350 psig, P_outlet=1,285 psig; Flow rate= 240,000 kg/day
• 6-stage, 60,000 rpm, 3.56 pressure ratio compressor
• Integral gearbox pinions driving individual, overhung impellers
• Design of compressor’s major mechanical elements completed and satisfied by two manufacturers per component
• KMC tilting pad radial and thrust bearings designs validated for use
• FlowServe single, gas face-seals have been validated for use
• Heat exchanger specifications met by two manufacturers to cool hydrogen gas to 100°F between stages
• Tranter Plate-type Heat Exchanger Design
• Heatric Heat Exchanger (compact, plate-fin surface core)