Advanced Sealing Technology for Hydrogen Compressors

In support of the hydrogen economy, the DOE seeks to develop delivery technologies for hydrogen as an energy carrier for transportation and stationary power. However, the 2003 DOE Strategic Initiatives for Hydrogen Delivery Workshop determined that existing hydrogen compressor designs cannot meet the need for a reliable, efficient, and cost-competitive transportation infrastructure. This project will develop non-contacting, low-leakage sealing technology for oil-free centrifugal hydrogen compressors capable of transporting up to 1,000,000 kg of hydrogen per day and compressing it from 300 psi to 1,000-2,000 psi. In Phase I, an existing foil seal design was enhanced for use with hydrogen, a subscale version of the enhanced design was fabricated, and preliminary static testing was conducted with air and helium to differential pressures of 100 and 250 psig respectively. The helium was used to simulate hydrogen. Leakage flow coefficients were determined to be substantially less than any other dynamic shaft seal. In Phase II, a full-scale seal will be fabricated, and low leakage will be demonstrated over a wide range of operating conditions. Commercial Applications and Other Benefits as described by the awardee: The seal technology should allow higher efficiency natural gas pipeline compressors to be built and operated, thereby enabling large-scale hydrogen gas delivery. Based upon the almost 50 million horsepower of natural gas pipeline compressors in service today, it is estimated that the use of oil-free, non-contacting bearings and seals ¿ in both hydrogen and natural gas pipeline compressors ¿ could yield a savings of 33,000 MW-hours of energy per year. Significant potential also exists for application of the sealing technology to more efficient gas turbine engines for aircraft.