Abstract:
Objective In response to the "dual-carbon" goals, achieve the low-carbon transformation of natural gas-fired power plants and meet the targets of low-carbon emissions, high energy conversion efficiency, and pollutant reduction.
Method Based on the 9F-class gas turbine, a swirl burner with a swirl number of 0.75~0.8 was designed. The GRI-Mech 3.0 chemical reaction model, large eddy simulation (LES), improved EDC + PDF turbulence-chemistry coupling model were used, combined with PCA and GSA, and research was carried out under multiple working conditions with a hydrogen blending ratio of 0%~30% and a pressure of 1.0~2.5 MPa.
Result When the hydrogen blending ratio was 15%~20%, the carbon emission intensity was reduced by 18%~23%, the energy efficiency was increased by 2.8%~3.5%, the NOx emission was stable at 42~48 mg/Nm3, and the CO emission was less than 50 mg/Nm3. When the hydrogen blending ratio reaches 30%, the NOx emission reaches 65 mg/Nm3, which was close to the international advanced standard. PCA and GSA show that the hydrogen blending ratio, operating pressure, and turbulence intensity contribute 85% to the NOx emission (R2>0.92).
Conclusion Compared with international advanced technologies, the dynamic turbulence regulation strategy of this study demonstrates the research potential in China, providing theoretical and practical support for the low-carbon upgrade of natural gas-fired power plants. However, there are still issues such as combustion instability and unclear hydrogen embrittlement mechanisms in high hydrogen blending ratios. Future research can focus on developing new burners, deeply exploring the hydrogen embrittlement mechanism, and combining machine learning to develop dynamic combustion control strategies to promote the development and wide application of natural gas hydrogen blending technology.