CHANGING LAW OF THERMO-PHYSICAL PROPERTIES OF HYDROGEN-BLENDED NATURAL GAS TRANSPORTED IN MEDIUM-AND LOW-PRESSURE PIPELINE

Hydrogen injection into natural gas pipeline network transportation changes the thermophysical properties of the original natural gas in the pipeline. The effects of pressure change, temperature variation (283.15～ 323.15 K) and hydrogen-blending volume ratio (0%～ 30%) on the thermophysical properties of hydrogen-blended natural gas in both low-pressure (0～1.6 MPa) and medium-pressure pipelines (1.6～10 MPa) were calculated and analyzed. As the hydrogen blending volume ratio increased, the Joule-Thomson coefficient, calorific value, Wobbe index, and viscosity of hydrogen-blended natural gas in the pipeline decreased, while the compression factor increased. The calorific value and Wobbe index of hydrogen-blended natural gas increased with rising pipeline pressure. The viscosity of hydrogen-blended natural gas decreased with increasing temperature, while the compression factor increases with increasing temperature. The results of this study can provide data reference and guidance for the implementation of hydrogen-blended natural gas projects in the future.