Abstract:
Objective Adding hydrogen into the natural gas pipeline network will change the composition and physical parameters of the gas, cause the operating point of the centrifugal compressor to shift, and affect the inlet and outlet pressure, power and energy consumption of the compressor. Therefore, it is necessary to analyze the adaptability of the operating conditions of the hydrogen-blending transport compressor.
Methods Taking the first-line West-East gas pipeline as the research object and considering the influence of hydrogen blending on the physical properties of natural gas, a calculation model of the centrifugal compressor characteristics of hydrogen-blended natural gas based on the similar conversion method was established. Furthermore, the simulation model of the hydrogen-blended natural gas pipeline with hydrogen admixture of 0%-20% was analyzed; the variation law of the pressure, temperature, operating point and performance parameters of the centrifugal compressor along the pipeline was analyzed before and after hydrogen blending under the same transmission capacity and the same calorific value.
Results For the same transmission conditions, when the transmission volume was (28-45)×106 m3/d and the hydrogen admixture was 0%-20%, the increase of hydrogen admixture by every 5% would cause the inlet pressure, outlet pressure and pressure head of the typical R-R compressor increase by 3.34%, 1.60% and 0.39% on average, respectively. It would also lead to the reduction of the self-consumption gas, power, and pressure ratio of the compressor by 0.35%, 4.11% and 1.64% on average, respectively. For the same calorific value, when the transmission volume was (28-35)×106 m3/d and the hydrogen admixture was 0%-20%, the increase of hydrogen admixture by every 5% would cause the inlet pressure, outlet pressure, consumable gas and power of typical R-R compressors increase 7.31%, 5.37%, 4.78% and 0.84% on average, respectively. It would also lead the head and pressure ratio decrease by 0.11% and 1.72% on average, respectively.
Conclusion The first-line pipeline compressor of the West-East gas pipeline is suitable for hydrogen-mixed transmission conditions.