Performance Analysis of Natural Gas Centrifugal Compressors Under Hydrogen-Blended Conditions

The transport of natural gas blended with hydrogen is a key strategy for the low-carbon energy transition. However, the influence mechanism of its thermo-physical property variations on centrifugal compressor performance remains insufficiently understood. This study systematically investigates the effects of the hydrogen blending ratio (HBR, 0–30%), inlet temperature, and rotational speed on key compressor parameters (pressure ratio, polytropic efficiency, and outlet temperature) through numerical simulations. In order to evaluate the influence of hydrogen blending on the performance and stability of centrifugal compressors, a three-dimensional model of the compressor was established, and the simulation conducted was verified with the experimental data. Results indicate that under constant inlet conditions, both the pressure ratio and outlet temperature decrease with increasing HBR, while polytropic efficiency remains relatively stable. Hydrogen blending significantly expands the surge margin, shifting both surge and choke lines downward, and consequently reducing the stable operating range by 27.11% when hydrogen content increases from 0% to 30%. This research provides theoretical foundations and practical guidance for optimizing hydrogen-blended natural gas centrifugal compressor design and operational control.