【摘要】 超临界水气化制氢循环发电系统是一种新型的煤炭清洁利用技术，在超临界环境下煤炭最终转化为H₂O与CO₂混合气进入透平做功，但混合气中的水蒸气在透平末级会发生非平衡凝结，造成叶片水蚀并伴随复杂激波现象。基于国内外研究现状，以MS喷管为研究对象，模拟研究了H₂O/CO₂混合工质的凝结流动特性，分析了CO₂质量分数和背压变化对流动参数分布及激波形态的影响。研究表明：CO₂的添加显著改变混合工质的凝结特性，CO₂质量分数从0增至0.4时，凝结区域向出口移动，出口温度降低5.24 K，液相质量分数减少2.28%；背压升高会驱使气动激波向上游移动，而凝结激波位置基本保持稳定，当气动激波覆盖凝结区域时，成核率趋近于零；在固定背压下，CO₂浓度增加不改变激波位置，但会使激波强度显著增强。更多还原

【Abstract】 The supercritical water gasification hydrogen production cycle power generation system is an innovative clean coal utilization technology. Under supercritical conditions, coal is ultimately converted into a H₂O/CO₂ gas mixture that enters the turbine for power generation. However,non-equilibrium condensation of water vapor occurs in the final turbine stage, leading to blade water erosion accompanied by complex shock wave phenomena. Based on current domestic and international research progress, this study employs an MS nozzle as the research object to numerically investigate the condensation flow characteristics of H₂O/CO₂ mixtures. The effects of CO₂ mass fraction and backpressure variations on flow parameter distributions and shock wave morphology are systematically analysed. Key findings include: the addition of CO₂ significantly alters the condensation characteristics of the working fluid. When the CO₂ mass fraction increases from 0 to 0.4, the condensation zone shifts toward the outlet, accompanied by a 5.24 K decrease in outlet temperature and a 2.28% reduction in liquid phase mass fraction; elevated backpressure drives aerodynamic shock waves upstream, while condensation-induced shock waves remain positionally stable,when aerodynamic shocks overlap the condensation zone, the nucleation rate approaches zero; under constant backpressure conditions, increasing CO₂ concentration does not alter shock wave positions but markedly enhances shock wave intensity.更多还原